Commit message: btrfs: merge btrfs_find_device and find_device

Both btrfs_find_device() and find_device() does the same thing except
that the latter does not take the seed device onto account in the device
scanning context. We can merge them.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
CVE: CVE-2019-18885
CWE: CWE-284
Vulnerability description: fs/btrfs/volumes.c in the Linux kernel before 5.1 allows a btrfs_verify_dev_extents NULL pointer dereference via a crafted btrfs image because fs_devices->devices is mishandled within find_device, aka CID-09ba3bc9dd15.

Project: linux
File: scrub.c

int scrub_enumerate_chunks(struct scrub_ctx *sctx,
			   struct btrfs_device *scrub_dev, u64 start, u64 end)
{
	struct btrfs_dev_extent *dev_extent = NULL;
	struct btrfs_path *path;
	struct btrfs_fs_info *fs_info = sctx->fs_info;
	struct btrfs_root *root = fs_info->dev_root;
	u64 length;
	u64 chunk_offset;
	int ret = 0;
	int ro_set;
	int slot;
	struct extent_buffer *l;
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct btrfs_block_group_cache *cache;
	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	path->reada = READA_FORWARD;
	path->search_commit_root = 1;
	path->skip_locking = 1;

	key.objectid = scrub_dev->devid;
	key.offset = 0ull;
	key.type = BTRFS_DEV_EXTENT_KEY;

	while (1) {
		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		if (ret < 0)
			break;
		if (ret > 0) {
			if (path->slots[0] >=
			    btrfs_header_nritems(path->nodes[0])) {
				ret = btrfs_next_leaf(root, path);
				if (ret < 0)
					break;
				if (ret > 0) {
					ret = 0;
					break;
				}
			} else {
				ret = 0;
			}
		}

		l = path->nodes[0];
		slot = path->slots[0];

		btrfs_item_key_to_cpu(l, &found_key, slot);

		if (found_key.objectid != scrub_dev->devid)
			break;

		if (found_key.type != BTRFS_DEV_EXTENT_KEY)
			break;

		if (found_key.offset >= end)
			break;

		if (found_key.offset < key.offset)
			break;

		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
		length = btrfs_dev_extent_length(l, dev_extent);

		if (found_key.offset + length <= start)
			goto skip;

		chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);

		/*
		 * get a reference on the corresponding block group to prevent
		 * the chunk from going away while we scrub it
		 */
		cache = btrfs_lookup_block_group(fs_info, chunk_offset);

		/* some chunks are removed but not committed to disk yet,
		 * continue scrubbing */
		if (!cache)
			goto skip;

		/*
		 * we need call btrfs_inc_block_group_ro() with scrubs_paused,
		 * to avoid deadlock caused by:
		 * btrfs_inc_block_group_ro()
		 * -> btrfs_wait_for_commit()
		 * -> btrfs_commit_transaction()
		 * -> btrfs_scrub_pause()
		 */
		scrub_pause_on(fs_info);
		ret = btrfs_inc_block_group_ro(cache);
		if (!ret && sctx->is_dev_replace) {
			/*
			 * If we are doing a device replace wait for any tasks
			 * that started delalloc right before we set the block
			 * group to RO mode, as they might have just allocated
			 * an extent from it or decided they could do a nocow
			 * write. And if any such tasks did that, wait for their
			 * ordered extents to complete and then commit the
			 * current transaction, so that we can later see the new
			 * extent items in the extent tree - the ordered extents
			 * create delayed data references (for cow writes) when
			 * they complete, which will be run and insert the
			 * corresponding extent items into the extent tree when
			 * we commit the transaction they used when running
			 * inode.c:btrfs_finish_ordered_io(). We later use
			 * the commit root of the extent tree to find extents
			 * to copy from the srcdev into the tgtdev, and we don't
			 * want to miss any new extents.
			 */
			btrfs_wait_block_group_reservations(cache);
			btrfs_wait_nocow_writers(cache);
			ret = btrfs_wait_ordered_roots(fs_info, U64_MAX,
						       cache->key.objectid,
						       cache->key.offset);
			if (ret > 0) {
				struct btrfs_trans_handle *trans;

				trans = btrfs_join_transaction(root);
				if (IS_ERR(trans))
					ret = PTR_ERR(trans);
				else
					ret = btrfs_commit_transaction(trans);
				if (ret) {
					scrub_pause_off(fs_info);
					btrfs_put_block_group(cache);
					break;
				}
			}
		}
		scrub_pause_off(fs_info);

		if (ret == 0) {
			ro_set = 1;
		} else if (ret == -ENOSPC) {
			/*
			 * btrfs_inc_block_group_ro return -ENOSPC when it
			 * failed in creating new chunk for metadata.
			 * It is not a problem for scrub/replace, because
			 * metadata are always cowed, and our scrub paused
			 * commit_transactions.
			 */
			ro_set = 0;
		} else {
			btrfs_warn(fs_info,
				   "failed setting block group ro: %d", ret);
			btrfs_put_block_group(cache);
			break;
		}

		down_write(&fs_info->dev_replace.rwsem);
		dev_replace->cursor_right = found_key.offset + length;
		dev_replace->cursor_left = found_key.offset;
		dev_replace->item_needs_writeback = 1;
		up_write(&dev_replace->rwsem);

		ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
				  found_key.offset, cache);

		/*
		 * flush, submit all pending read and write bios, afterwards
		 * wait for them.
		 * Note that in the dev replace case, a read request causes
		 * write requests that are submitted in the read completion
		 * worker. Therefore in the current situation, it is required
		 * that all write requests are flushed, so that all read and
		 * write requests are really completed when bios_in_flight
		 * changes to 0.
		 */
		sctx->flush_all_writes = true;
		scrub_submit(sctx);
		mutex_lock(&sctx->wr_lock);
		scrub_wr_submit(sctx);
		mutex_unlock(&sctx->wr_lock);

		wait_event(sctx->list_wait,
			   atomic_read(&sctx->bios_in_flight) == 0);

		scrub_pause_on(fs_info);

		/*
		 * must be called before we decrease @scrub_paused.
		 * make sure we don't block transaction commit while
		 * we are waiting pending workers finished.
		 */
		wait_event(sctx->list_wait,
			   atomic_read(&sctx->workers_pending) == 0);
		sctx->flush_all_writes = false;

		scrub_pause_off(fs_info);

		down_write(&fs_info->dev_replace.rwsem);
		dev_replace->cursor_left = dev_replace->cursor_right;
		dev_replace->item_needs_writeback = 1;
		up_write(&fs_info->dev_replace.rwsem);

		if (ro_set)
			btrfs_dec_block_group_ro(cache);

		/*
		 * We might have prevented the cleaner kthread from deleting
		 * this block group if it was already unused because we raced
		 * and set it to RO mode first. So add it back to the unused
		 * list, otherwise it might not ever be deleted unless a manual
		 * balance is triggered or it becomes used and unused again.
		 */
		spin_lock(&cache->lock);
		if (!cache->removed && !cache->ro && cache->reserved == 0 &&
		    btrfs_block_group_used(&cache->item) == 0) {
			spin_unlock(&cache->lock);
			btrfs_mark_bg_unused(cache);
		} else {
			spin_unlock(&cache->lock);
		}

		btrfs_put_block_group(cache);
		if (ret)
			break;
		if (sctx->is_dev_replace &&
		    atomic64_read(&dev_replace->num_write_errors) > 0) {
			ret = -EIO;
			break;
		}
		if (sctx->stat.malloc_errors > 0) {
			ret = -ENOMEM;
			break;
		}
skip:
		key.offset = found_key.offset + length;
		btrfs_release_path(path);
	}

	btrfs_free_path(path);

	return ret;
}

Project: linux
File: ioctl.c

static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
{
	struct inode *inode = file_inode(file);
	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_super_block *super_block = fs_info->super_copy;
	struct btrfs_trans_handle *trans;
	char label[BTRFS_LABEL_SIZE];
	int ret;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	if (copy_from_user(label, arg, sizeof(label)))
		return -EFAULT;

	if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
		btrfs_err(fs_info,
			  "unable to set label with more than %d bytes",
			  BTRFS_LABEL_SIZE - 1);
		return -EINVAL;
	}

	ret = mnt_want_write_file(file);
	if (ret)
		return ret;

	trans = btrfs_start_transaction(root, 0);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		goto out_unlock;
	}

	spin_lock(&fs_info->super_lock);
	strcpy(super_block->label, label);
	spin_unlock(&fs_info->super_lock);
	ret = btrfs_commit_transaction(trans);

out_unlock:
	mnt_drop_write_file(file);
	return ret;
}

Project: linux
File: volumes.c

static u64 calc_stripe_length(u64 type, u64 chunk_len, int num_stripes)
{
	int index = btrfs_bg_flags_to_raid_index(type);
	int ncopies = btrfs_raid_array[index].ncopies;
	int data_stripes;

	switch (type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
	case BTRFS_BLOCK_GROUP_RAID5:
		data_stripes = num_stripes - 1;
		break;
	case BTRFS_BLOCK_GROUP_RAID6:
		data_stripes = num_stripes - 2;
		break;
	default:
		data_stripes = num_stripes / ncopies;
		break;
	}
	return div_u64(chunk_len, data_stripes);
}

Project: linux
File: dev-replace.c

static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info)
{
	set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state);
	wait_event(fs_info->dev_replace.replace_wait, !percpu_counter_sum(
		   &fs_info->dev_replace.bio_counter));
}

Project: linux
File: scrub.c

void btrfs_scrub_continue(struct btrfs_fs_info *fs_info)
{
	atomic_dec(&fs_info->scrub_pause_req);
	wake_up(&fs_info->scrub_pause_wait);
}

Project: linux
File: volumes.c

static int read_one_chunk(struct btrfs_fs_info *fs_info, struct btrfs_key *key,
			  struct extent_buffer *leaf,
			  struct btrfs_chunk *chunk)
{
	struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
	struct map_lookup *map;
	struct extent_map *em;
	u64 logical;
	u64 length;
	u64 devid;
	u8 uuid[BTRFS_UUID_SIZE];
	int num_stripes;
	int ret;
	int i;

	logical = key->offset;
	length = btrfs_chunk_length(leaf, chunk);
	num_stripes = btrfs_chunk_num_stripes(leaf, chunk);

	ret = btrfs_check_chunk_valid(fs_info, leaf, chunk, logical);
	if (ret)
		return ret;

	read_lock(&map_tree->map_tree.lock);
	em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
	read_unlock(&map_tree->map_tree.lock);

	/* already mapped? */
	if (em && em->start <= logical && em->start + em->len > logical) {
		free_extent_map(em);
		return 0;
	} else if (em) {
		free_extent_map(em);
	}

	em = alloc_extent_map();
	if (!em)
		return -ENOMEM;
	map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
	if (!map) {
		free_extent_map(em);
		return -ENOMEM;
	}

	set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
	em->map_lookup = map;
	em->start = logical;
	em->len = length;
	em->orig_start = 0;
	em->block_start = 0;
	em->block_len = em->len;

	map->num_stripes = num_stripes;
	map->io_width = btrfs_chunk_io_width(leaf, chunk);
	map->io_align = btrfs_chunk_io_align(leaf, chunk);
	map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
	map->type = btrfs_chunk_type(leaf, chunk);
	map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
	map->verified_stripes = 0;
	for (i = 0; i < num_stripes; i++) {
		map->stripes[i].physical =
			btrfs_stripe_offset_nr(leaf, chunk, i);
		devid = btrfs_stripe_devid_nr(leaf, chunk, i);
		read_extent_buffer(leaf, uuid, (unsigned long)
				   btrfs_stripe_dev_uuid_nr(chunk, i),
				   BTRFS_UUID_SIZE);
		map->stripes[i].dev = btrfs_find_device(fs_info->fs_devices,
							devid, uuid, NULL, true);
		if (!map->stripes[i].dev &&
		    !btrfs_test_opt(fs_info, DEGRADED)) {
			free_extent_map(em);
			btrfs_report_missing_device(fs_info, devid, uuid, true);
			return -ENOENT;
		}
		if (!map->stripes[i].dev) {
			map->stripes[i].dev =
				add_missing_dev(fs_info->fs_devices, devid,
						uuid);
			if (IS_ERR(map->stripes[i].dev)) {
				free_extent_map(em);
				btrfs_err(fs_info,
					"failed to init missing dev %llu: %ld",
					devid, PTR_ERR(map->stripes[i].dev));
				return PTR_ERR(map->stripes[i].dev);
			}
			btrfs_report_missing_device(fs_info, devid, uuid, false);
		}
		set_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
				&(map->stripes[i].dev->dev_state));

	}

	write_lock(&map_tree->map_tree.lock);
	ret = add_extent_mapping(&map_tree->map_tree, em, 0);
	write_unlock(&map_tree->map_tree.lock);
	if (ret < 0) {
		btrfs_err(fs_info,
			  "failed to add chunk map, start=%llu len=%llu: %d",
			  em->start, em->len, ret);
	}
	free_extent_map(em);

	return ret;
}

Project: linux
File: volumes.c

void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step)
{
	struct btrfs_device *device, *next;
	struct btrfs_device *latest_dev = NULL;

	mutex_lock(&uuid_mutex);
again:
	/* This is the initialized path, it is safe to release the devices. */
	list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
		if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
							&device->dev_state)) {
			if (!test_bit(BTRFS_DEV_STATE_REPLACE_TGT,
			     &device->dev_state) &&
			     (!latest_dev ||
			      device->generation > latest_dev->generation)) {
				latest_dev = device;
			}
			continue;
		}

		if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
			/*
			 * In the first step, keep the device which has
			 * the correct fsid and the devid that is used
			 * for the dev_replace procedure.
			 * In the second step, the dev_replace state is
			 * read from the device tree and it is known
			 * whether the procedure is really active or
			 * not, which means whether this device is
			 * used or whether it should be removed.
			 */
			if (step == 0 || test_bit(BTRFS_DEV_STATE_REPLACE_TGT,
						  &device->dev_state)) {
				continue;
			}
		}
		if (device->bdev) {
			blkdev_put(device->bdev, device->mode);
			device->bdev = NULL;
			fs_devices->open_devices--;
		}
		if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
			list_del_init(&device->dev_alloc_list);
			clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
			if (!test_bit(BTRFS_DEV_STATE_REPLACE_TGT,
				      &device->dev_state))
				fs_devices->rw_devices--;
		}
		list_del_init(&device->dev_list);
		fs_devices->num_devices--;
		btrfs_free_device(device);
	}

	if (fs_devices->seed) {
		fs_devices = fs_devices->seed;
		goto again;
	}

	fs_devices->latest_bdev = latest_dev->bdev;

	mutex_unlock(&uuid_mutex);
}

Project: linux
File: ioctl.c

static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
{
	struct btrfs_ioctl_get_subvol_info_args *subvol_info;
	struct btrfs_fs_info *fs_info;
	struct btrfs_root *root;
	struct btrfs_path *path;
	struct btrfs_key key;
	struct btrfs_root_item *root_item;
	struct btrfs_root_ref *rref;
	struct extent_buffer *leaf;
	unsigned long item_off;
	unsigned long item_len;
	struct inode *inode;
	int slot;
	int ret = 0;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
	if (!subvol_info) {
		btrfs_free_path(path);
		return -ENOMEM;
	}

	inode = file_inode(file);
	fs_info = BTRFS_I(inode)->root->fs_info;

	/* Get root_item of inode's subvolume */
	key.objectid = BTRFS_I(inode)->root->root_key.objectid;
	key.type = BTRFS_ROOT_ITEM_KEY;
	key.offset = (u64)-1;
	root = btrfs_read_fs_root_no_name(fs_info, &key);
	if (IS_ERR(root)) {
		ret = PTR_ERR(root);
		goto out;
	}
	root_item = &root->root_item;

	subvol_info->treeid = key.objectid;

	subvol_info->generation = btrfs_root_generation(root_item);
	subvol_info->flags = btrfs_root_flags(root_item);

	memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
	memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
						    BTRFS_UUID_SIZE);
	memcpy(subvol_info->received_uuid, root_item->received_uuid,
						    BTRFS_UUID_SIZE);

	subvol_info->ctransid = btrfs_root_ctransid(root_item);
	subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
	subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);

	subvol_info->otransid = btrfs_root_otransid(root_item);
	subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
	subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);

	subvol_info->stransid = btrfs_root_stransid(root_item);
	subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
	subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);

	subvol_info->rtransid = btrfs_root_rtransid(root_item);
	subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
	subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);

	if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
		/* Search root tree for ROOT_BACKREF of this subvolume */
		root = fs_info->tree_root;

		key.type = BTRFS_ROOT_BACKREF_KEY;
		key.offset = 0;
		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		if (ret < 0) {
			goto out;
		} else if (path->slots[0] >=
			   btrfs_header_nritems(path->nodes[0])) {
			ret = btrfs_next_leaf(root, path);
			if (ret < 0) {
				goto out;
			} else if (ret > 0) {
				ret = -EUCLEAN;
				goto out;
			}
		}

		leaf = path->nodes[0];
		slot = path->slots[0];
		btrfs_item_key_to_cpu(leaf, &key, slot);
		if (key.objectid == subvol_info->treeid &&
		    key.type == BTRFS_ROOT_BACKREF_KEY) {
			subvol_info->parent_id = key.offset;

			rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
			subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);

			item_off = btrfs_item_ptr_offset(leaf, slot)
					+ sizeof(struct btrfs_root_ref);
			item_len = btrfs_item_size_nr(leaf, slot)
					- sizeof(struct btrfs_root_ref);
			read_extent_buffer(leaf, subvol_info->name,
					   item_off, item_len);
		} else {
			ret = -ENOENT;
			goto out;
		}
	}

	if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
		ret = -EFAULT;

out:
	btrfs_free_path(path);
	kzfree(subvol_info);
	return ret;
}

Project: linux
File: volumes.c

static void sort_parity_stripes(struct btrfs_bio *bbio, int num_stripes)
{
	struct btrfs_bio_stripe s;
	int i;
	u64 l;
	int again = 1;

	while (again) {
		again = 0;
		for (i = 0; i < num_stripes - 1; i++) {
			if (parity_smaller(bbio->raid_map[i],
					   bbio->raid_map[i+1])) {
				s = bbio->stripes[i];
				l = bbio->raid_map[i];
				bbio->stripes[i] = bbio->stripes[i+1];
				bbio->raid_map[i] = bbio->raid_map[i+1];
				bbio->stripes[i+1] = s;
				bbio->raid_map[i+1] = l;

				again = 1;
			}
		}
	}
}

Project: linux
File: scrub.c

static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
{
	struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
	struct scrub_ctx *sctx = sbio->sctx;
	int i;

	WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
	if (sbio->status) {
		struct btrfs_dev_replace *dev_replace =
			&sbio->sctx->fs_info->dev_replace;

		for (i = 0; i < sbio->page_count; i++) {
			struct scrub_page *spage = sbio->pagev[i];

			spage->io_error = 1;
			atomic64_inc(&dev_replace->num_write_errors);
		}
	}

	for (i = 0; i < sbio->page_count; i++)
		scrub_page_put(sbio->pagev[i]);

	bio_put(sbio->bio);
	kfree(sbio);
	scrub_pending_bio_dec(sctx);
}

Project: linux
File: volumes.c

static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info)
{
	struct btrfs_root *chunk_root = fs_info->chunk_root;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_chunk *chunk;
	struct btrfs_key key;
	struct btrfs_key found_key;
	u64 chunk_type;
	bool retried = false;
	int failed = 0;
	int ret;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

again:
	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
	key.offset = (u64)-1;
	key.type = BTRFS_CHUNK_ITEM_KEY;

	while (1) {
		mutex_lock(&fs_info->delete_unused_bgs_mutex);
		ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
		if (ret < 0) {
			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
			goto error;
		}
		BUG_ON(ret == 0); /* Corruption */

		ret = btrfs_previous_item(chunk_root, path, key.objectid,
					  key.type);
		if (ret)
			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
		if (ret < 0)
			goto error;
		if (ret > 0)
			break;

		leaf = path->nodes[0];
		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);

		chunk = btrfs_item_ptr(leaf, path->slots[0],
				       struct btrfs_chunk);
		chunk_type = btrfs_chunk_type(leaf, chunk);
		btrfs_release_path(path);

		if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
			ret = btrfs_relocate_chunk(fs_info, found_key.offset);
			if (ret == -ENOSPC)
				failed++;
			else
				BUG_ON(ret);
		}
		mutex_unlock(&fs_info->delete_unused_bgs_mutex);

		if (found_key.offset == 0)
			break;
		key.offset = found_key.offset - 1;
	}
	ret = 0;
	if (failed && !retried) {
		failed = 0;
		retried = true;
		goto again;
	} else if (WARN_ON(failed && retried)) {
		ret = -ENOSPC;
	}
error:
	btrfs_free_path(path);
	return ret;
}

Project: linux
File: volumes.c

static struct btrfs_fs_devices *find_fsid_changed(
					struct btrfs_super_block *disk_super)
{
	struct btrfs_fs_devices *fs_devices;

	/*
	 * Handles the case where scanned device is part of an fs that had
	 * multiple successful changes of FSID but curently device didn't
	 * observe it. Meaning our fsid will be different than theirs.
	 */
	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
		if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,
			   BTRFS_FSID_SIZE) != 0 &&
		    memcmp(fs_devices->metadata_uuid, disk_super->metadata_uuid,
			   BTRFS_FSID_SIZE) == 0 &&
		    memcmp(fs_devices->fsid, disk_super->fsid,
			   BTRFS_FSID_SIZE) != 0) {
			return fs_devices;
		}
	}

	return NULL;
}

Project: linux
File: volumes.c

void btrfs_assign_next_active_device(struct btrfs_device *device,
				     struct btrfs_device *this_dev)
{
	struct btrfs_fs_info *fs_info = device->fs_info;
	struct btrfs_device *next_device;

	if (this_dev)
		next_device = this_dev;
	else
		next_device = btrfs_find_next_active_device(fs_info->fs_devices,
								device);
	ASSERT(next_device);

	if (fs_info->sb->s_bdev &&
			(fs_info->sb->s_bdev == device->bdev))
		fs_info->sb->s_bdev = next_device->bdev;

	if (fs_info->fs_devices->latest_bdev == device->bdev)
		fs_info->fs_devices->latest_bdev = next_device->bdev;
}

Project: linux
File: ioctl.c

static unsigned int btrfs_inode_flags_to_xflags(unsigned int flags)
{
	unsigned int xflags = 0;

	if (flags & BTRFS_INODE_APPEND)
		xflags |= FS_XFLAG_APPEND;
	if (flags & BTRFS_INODE_IMMUTABLE)
		xflags |= FS_XFLAG_IMMUTABLE;
	if (flags & BTRFS_INODE_NOATIME)
		xflags |= FS_XFLAG_NOATIME;
	if (flags & BTRFS_INODE_NODUMP)
		xflags |= FS_XFLAG_NODUMP;
	if (flags & BTRFS_INODE_SYNC)
		xflags |= FS_XFLAG_SYNC;

	return xflags;
}

Project: linux
File: ioctl.c

static void get_block_group_info(struct list_head *groups_list,
				 struct btrfs_ioctl_space_info *space)
{
	struct btrfs_block_group_cache *block_group;

	space->total_bytes = 0;
	space->used_bytes = 0;
	space->flags = 0;
	list_for_each_entry(block_group, groups_list, list) {
		space->flags = block_group->flags;
		space->total_bytes += block_group->key.offset;
		space->used_bytes +=
			btrfs_block_group_used(&block_group->item);
	}
}

Project: linux
File: volumes.c

static void btrfs_release_disk_super(struct page *page)
{
	kunmap(page);
	put_page(page);
}

Project: linux
File: volumes.c

static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
			       u64 start, u64 type)
{
	struct btrfs_fs_info *info = trans->fs_info;
	struct btrfs_fs_devices *fs_devices = info->fs_devices;
	struct btrfs_device *device;
	struct map_lookup *map = NULL;
	struct extent_map_tree *em_tree;
	struct extent_map *em;
	struct btrfs_device_info *devices_info = NULL;
	u64 total_avail;
	int num_stripes;	/* total number of stripes to allocate */
	int data_stripes;	/* number of stripes that count for
				   block group size */
	int sub_stripes;	/* sub_stripes info for map */
	int dev_stripes;	/* stripes per dev */
	int devs_max;		/* max devs to use */
	int devs_min;		/* min devs needed */
	int devs_increment;	/* ndevs has to be a multiple of this */
	int ncopies;		/* how many copies to data has */
	int nparity;		/* number of stripes worth of bytes to
				   store parity information */
	int ret;
	u64 max_stripe_size;
	u64 max_chunk_size;
	u64 stripe_size;
	u64 chunk_size;
	int ndevs;
	int i;
	int j;
	int index;

	BUG_ON(!alloc_profile_is_valid(type, 0));

	if (list_empty(&fs_devices->alloc_list)) {
		if (btrfs_test_opt(info, ENOSPC_DEBUG))
			btrfs_debug(info, "%s: no writable device", __func__);
		return -ENOSPC;
	}

	index = btrfs_bg_flags_to_raid_index(type);

	sub_stripes = btrfs_raid_array[index].sub_stripes;
	dev_stripes = btrfs_raid_array[index].dev_stripes;
	devs_max = btrfs_raid_array[index].devs_max;
	devs_min = btrfs_raid_array[index].devs_min;
	devs_increment = btrfs_raid_array[index].devs_increment;
	ncopies = btrfs_raid_array[index].ncopies;
	nparity = btrfs_raid_array[index].nparity;

	if (type & BTRFS_BLOCK_GROUP_DATA) {
		max_stripe_size = SZ_1G;
		max_chunk_size = BTRFS_MAX_DATA_CHUNK_SIZE;
		if (!devs_max)
			devs_max = BTRFS_MAX_DEVS(info);
	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
		/* for larger filesystems, use larger metadata chunks */
		if (fs_devices->total_rw_bytes > 50ULL * SZ_1G)
			max_stripe_size = SZ_1G;
		else
			max_stripe_size = SZ_256M;
		max_chunk_size = max_stripe_size;
		if (!devs_max)
			devs_max = BTRFS_MAX_DEVS(info);
	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
		max_stripe_size = SZ_32M;
		max_chunk_size = 2 * max_stripe_size;
		if (!devs_max)
			devs_max = BTRFS_MAX_DEVS_SYS_CHUNK;
	} else {
		btrfs_err(info, "invalid chunk type 0x%llx requested",
		       type);
		BUG_ON(1);
	}

	/* We don't want a chunk larger than 10% of writable space */
	max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
			     max_chunk_size);

	devices_info = kcalloc(fs_devices->rw_devices, sizeof(*devices_info),
			       GFP_NOFS);
	if (!devices_info)
		return -ENOMEM;

	/*
	 * in the first pass through the devices list, we gather information
	 * about the available holes on each device.
	 */
	ndevs = 0;
	list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
		u64 max_avail;
		u64 dev_offset;

		if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
			WARN(1, KERN_ERR
			       "BTRFS: read-only device in alloc_list\n");
			continue;
		}

		if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
					&device->dev_state) ||
		    test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
			continue;

		if (device->total_bytes > device->bytes_used)
			total_avail = device->total_bytes - device->bytes_used;
		else
			total_avail = 0;

		/* If there is no space on this device, skip it. */
		if (total_avail == 0)
			continue;

		ret = find_free_dev_extent(trans, device,
					   max_stripe_size * dev_stripes,
					   &dev_offset, &max_avail);
		if (ret && ret != -ENOSPC)
			goto error;

		if (ret == 0)
			max_avail = max_stripe_size * dev_stripes;

		if (max_avail < BTRFS_STRIPE_LEN * dev_stripes) {
			if (btrfs_test_opt(info, ENOSPC_DEBUG))
				btrfs_debug(info,
			"%s: devid %llu has no free space, have=%llu want=%u",
					    __func__, device->devid, max_avail,
					    BTRFS_STRIPE_LEN * dev_stripes);
			continue;
		}

		if (ndevs == fs_devices->rw_devices) {
			WARN(1, "%s: found more than %llu devices\n",
			     __func__, fs_devices->rw_devices);
			break;
		}
		devices_info[ndevs].dev_offset = dev_offset;
		devices_info[ndevs].max_avail = max_avail;
		devices_info[ndevs].total_avail = total_avail;
		devices_info[ndevs].dev = device;
		++ndevs;
	}

	/*
	 * now sort the devices by hole size / available space
	 */
	sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
	     btrfs_cmp_device_info, NULL);

	/* round down to number of usable stripes */
	ndevs = round_down(ndevs, devs_increment);

	if (ndevs < devs_min) {
		ret = -ENOSPC;
		if (btrfs_test_opt(info, ENOSPC_DEBUG)) {
			btrfs_debug(info,
	"%s: not enough devices with free space: have=%d minimum required=%d",
				    __func__, ndevs, devs_min);
		}
		goto error;
	}

	ndevs = min(ndevs, devs_max);

	/*
	 * The primary goal is to maximize the number of stripes, so use as
	 * many devices as possible, even if the stripes are not maximum sized.
	 *
	 * The DUP profile stores more than one stripe per device, the
	 * max_avail is the total size so we have to adjust.
	 */
	stripe_size = div_u64(devices_info[ndevs - 1].max_avail, dev_stripes);
	num_stripes = ndevs * dev_stripes;

	/*
	 * this will have to be fixed for RAID1 and RAID10 over
	 * more drives
	 */
	data_stripes = (num_stripes - nparity) / ncopies;

	/*
	 * Use the number of data stripes to figure out how big this chunk
	 * is really going to be in terms of logical address space,
	 * and compare that answer with the max chunk size. If it's higher,
	 * we try to reduce stripe_size.
	 */
	if (stripe_size * data_stripes > max_chunk_size) {
		/*
		 * Reduce stripe_size, round it up to a 16MB boundary again and
		 * then use it, unless it ends up being even bigger than the
		 * previous value we had already.
		 */
		stripe_size = min(round_up(div_u64(max_chunk_size,
						   data_stripes), SZ_16M),
				  stripe_size);
	}

	/* align to BTRFS_STRIPE_LEN */
	stripe_size = round_down(stripe_size, BTRFS_STRIPE_LEN);

	map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
	if (!map) {
		ret = -ENOMEM;
		goto error;
	}
	map->num_stripes = num_stripes;

	for (i = 0; i < ndevs; ++i) {
		for (j = 0; j < dev_stripes; ++j) {
			int s = i * dev_stripes + j;
			map->stripes[s].dev = devices_info[i].dev;
			map->stripes[s].physical = devices_info[i].dev_offset +
						   j * stripe_size;
		}
	}
	map->stripe_len = BTRFS_STRIPE_LEN;
	map->io_align = BTRFS_STRIPE_LEN;
	map->io_width = BTRFS_STRIPE_LEN;
	map->type = type;
	map->sub_stripes = sub_stripes;

	chunk_size = stripe_size * data_stripes;

	trace_btrfs_chunk_alloc(info, map, start, chunk_size);

	em = alloc_extent_map();
	if (!em) {
		kfree(map);
		ret = -ENOMEM;
		goto error;
	}
	set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
	em->map_lookup = map;
	em->start = start;
	em->len = chunk_size;
	em->block_start = 0;
	em->block_len = em->len;
	em->orig_block_len = stripe_size;

	em_tree = &info->mapping_tree.map_tree;
	write_lock(&em_tree->lock);
	ret = add_extent_mapping(em_tree, em, 0);
	if (ret) {
		write_unlock(&em_tree->lock);
		free_extent_map(em);
		goto error;
	}

	list_add_tail(&em->list, &trans->transaction->pending_chunks);
	refcount_inc(&em->refs);
	write_unlock(&em_tree->lock);

	ret = btrfs_make_block_group(trans, 0, type, start, chunk_size);
	if (ret)
		goto error_del_extent;

	for (i = 0; i < map->num_stripes; i++)
		btrfs_device_set_bytes_used(map->stripes[i].dev,
				map->stripes[i].dev->bytes_used + stripe_size);

	atomic64_sub(stripe_size * map->num_stripes, &info->free_chunk_space);

	free_extent_map(em);
	check_raid56_incompat_flag(info, type);

	kfree(devices_info);
	return 0;

error_del_extent:
	write_lock(&em_tree->lock);
	remove_extent_mapping(em_tree, em);
	write_unlock(&em_tree->lock);

	/* One for our allocation */
	free_extent_map(em);
	/* One for the tree reference */
	free_extent_map(em);
	/* One for the pending_chunks list reference */
	free_extent_map(em);
error:
	kfree(devices_info);
	return ret;
}

Project: linux
File: volumes.c

static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
				  struct btrfs_device *device,
				  u64 chunk_offset, u64 start, u64 num_bytes)
{
	int ret;
	struct btrfs_path *path;
	struct btrfs_fs_info *fs_info = device->fs_info;
	struct btrfs_root *root = fs_info->dev_root;
	struct btrfs_dev_extent *extent;
	struct extent_buffer *leaf;
	struct btrfs_key key;

	WARN_ON(!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state));
	WARN_ON(test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state));
	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	key.objectid = device->devid;
	key.offset = start;
	key.type = BTRFS_DEV_EXTENT_KEY;
	ret = btrfs_insert_empty_item(trans, root, path, &key,
				      sizeof(*extent));
	if (ret)
		goto out;

	leaf = path->nodes[0];
	extent = btrfs_item_ptr(leaf, path->slots[0],
				struct btrfs_dev_extent);
	btrfs_set_dev_extent_chunk_tree(leaf, extent,
					BTRFS_CHUNK_TREE_OBJECTID);
	btrfs_set_dev_extent_chunk_objectid(leaf, extent,
					    BTRFS_FIRST_CHUNK_TREE_OBJECTID);
	btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);

	btrfs_set_dev_extent_length(leaf, extent, num_bytes);
	btrfs_mark_buffer_dirty(leaf);
out:
	btrfs_free_path(path);
	return ret;
}

Project: linux
File: scrub.c

static void scrub_put_ctx(struct scrub_ctx *sctx)
{
	if (refcount_dec_and_test(&sctx->refs))
		scrub_free_ctx(sctx);
}

Project: linux
File: ioctl.c

static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
{
	struct btrfs_ioctl_send_args *arg;
	int ret;

	if (compat) {
#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
		struct btrfs_ioctl_send_args_32 args32;

		ret = copy_from_user(&args32, argp, sizeof(args32));
		if (ret)
			return -EFAULT;
		arg = kzalloc(sizeof(*arg), GFP_KERNEL);
		if (!arg)
			return -ENOMEM;
		arg->send_fd = args32.send_fd;
		arg->clone_sources_count = args32.clone_sources_count;
		arg->clone_sources = compat_ptr(args32.clone_sources);
		arg->parent_root = args32.parent_root;
		arg->flags = args32.flags;
		memcpy(arg->reserved, args32.reserved,
		       sizeof(args32.reserved));
#else
		return -ENOTTY;
#endif
	} else {
		arg = memdup_user(argp, sizeof(*arg));
		if (IS_ERR(arg))
			return PTR_ERR(arg);
	}
	ret = btrfs_ioctl_send(file, arg);
	kfree(arg);
	return ret;
}

Project: linux
File: volumes.c

int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
			     u64 chunk_offset, u64 chunk_size)
{
	struct btrfs_fs_info *fs_info = trans->fs_info;
	struct btrfs_root *extent_root = fs_info->extent_root;
	struct btrfs_root *chunk_root = fs_info->chunk_root;
	struct btrfs_key key;
	struct btrfs_device *device;
	struct btrfs_chunk *chunk;
	struct btrfs_stripe *stripe;
	struct extent_map *em;
	struct map_lookup *map;
	size_t item_size;
	u64 dev_offset;
	u64 stripe_size;
	int i = 0;
	int ret = 0;

	em = btrfs_get_chunk_map(fs_info, chunk_offset, chunk_size);
	if (IS_ERR(em))
		return PTR_ERR(em);

	map = em->map_lookup;
	item_size = btrfs_chunk_item_size(map->num_stripes);
	stripe_size = em->orig_block_len;

	chunk = kzalloc(item_size, GFP_NOFS);
	if (!chunk) {
		ret = -ENOMEM;
		goto out;
	}

	/*
	 * Take the device list mutex to prevent races with the final phase of
	 * a device replace operation that replaces the device object associated
	 * with the map's stripes, because the device object's id can change
	 * at any time during that final phase of the device replace operation
	 * (dev-replace.c:btrfs_dev_replace_finishing()).
	 */
	mutex_lock(&fs_info->fs_devices->device_list_mutex);
	for (i = 0; i < map->num_stripes; i++) {
		device = map->stripes[i].dev;
		dev_offset = map->stripes[i].physical;

		ret = btrfs_update_device(trans, device);
		if (ret)
			break;
		ret = btrfs_alloc_dev_extent(trans, device, chunk_offset,
					     dev_offset, stripe_size);
		if (ret)
			break;
	}
	if (ret) {
		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
		goto out;
	}

	stripe = &chunk->stripe;
	for (i = 0; i < map->num_stripes; i++) {
		device = map->stripes[i].dev;
		dev_offset = map->stripes[i].physical;

		btrfs_set_stack_stripe_devid(stripe, device->devid);
		btrfs_set_stack_stripe_offset(stripe, dev_offset);
		memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
		stripe++;
	}
	mutex_unlock(&fs_info->fs_devices->device_list_mutex);

	btrfs_set_stack_chunk_length(chunk, chunk_size);
	btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
	btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
	btrfs_set_stack_chunk_type(chunk, map->type);
	btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
	btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
	btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
	btrfs_set_stack_chunk_sector_size(chunk, fs_info->sectorsize);
	btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);

	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
	key.type = BTRFS_CHUNK_ITEM_KEY;
	key.offset = chunk_offset;

	ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
	if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
		/*
		 * TODO: Cleanup of inserted chunk root in case of
		 * failure.
		 */
		ret = btrfs_add_system_chunk(fs_info, &key, chunk, item_size);
	}

out:
	kfree(chunk);
	free_extent_map(em);
	return ret;
}

Project: linux
File: volumes.c

btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
		      int flush, struct block_device **bdev,
		      struct buffer_head **bh)
{
	int ret;

	*bdev = blkdev_get_by_path(device_path, flags, holder);

	if (IS_ERR(*bdev)) {
		ret = PTR_ERR(*bdev);
		goto error;
	}

	if (flush)
		filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
	ret = set_blocksize(*bdev, BTRFS_BDEV_BLOCKSIZE);
	if (ret) {
		blkdev_put(*bdev, flags);
		goto error;
	}
	invalidate_bdev(*bdev);
	*bh = btrfs_read_dev_super(*bdev);
	if (IS_ERR(*bh)) {
		ret = PTR_ERR(*bh);
		blkdev_put(*bdev, flags);
		goto error;
	}

	return 0;

error:
	*bdev = NULL;
	*bh = NULL;
	return ret;
}

Project: linux
File: scrub.c

static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
					  struct btrfs_device *scrub_dev,
					  u64 chunk_offset, u64 length,
					  u64 dev_offset,
					  struct btrfs_block_group_cache *cache)
{
	struct btrfs_fs_info *fs_info = sctx->fs_info;
	struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
	struct map_lookup *map;
	struct extent_map *em;
	int i;
	int ret = 0;

	read_lock(&map_tree->map_tree.lock);
	em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
	read_unlock(&map_tree->map_tree.lock);

	if (!em) {
		/*
		 * Might have been an unused block group deleted by the cleaner
		 * kthread or relocation.
		 */
		spin_lock(&cache->lock);
		if (!cache->removed)
			ret = -EINVAL;
		spin_unlock(&cache->lock);

		return ret;
	}

	map = em->map_lookup;
	if (em->start != chunk_offset)
		goto out;

	if (em->len < length)
		goto out;

	for (i = 0; i < map->num_stripes; ++i) {
		if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
		    map->stripes[i].physical == dev_offset) {
			ret = scrub_stripe(sctx, map, scrub_dev, i,
					   chunk_offset, length);
			if (ret)
				goto out;
		}
	}
out:
	free_extent_map(em);

	return ret;
}

Project: linux
File: volumes.c

static noinline struct btrfs_fs_devices *find_fsid(
		const u8 *fsid, const u8 *metadata_fsid)
{
	struct btrfs_fs_devices *fs_devices;

	ASSERT(fsid);

	if (metadata_fsid) {
		/*
		 * Handle scanned device having completed its fsid change but
		 * belonging to a fs_devices that was created by first scanning
		 * a device which didn't have its fsid/metadata_uuid changed
		 * at all and the CHANGING_FSID_V2 flag set.
		 */
		list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
			if (fs_devices->fsid_change &&
			    memcmp(metadata_fsid, fs_devices->fsid,
				   BTRFS_FSID_SIZE) == 0 &&
			    memcmp(fs_devices->fsid, fs_devices->metadata_uuid,
				   BTRFS_FSID_SIZE) == 0) {
				return fs_devices;
			}
		}
		/*
		 * Handle scanned device having completed its fsid change but
		 * belonging to a fs_devices that was created by a device that
		 * has an outdated pair of fsid/metadata_uuid and
		 * CHANGING_FSID_V2 flag set.
		 */
		list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
			if (fs_devices->fsid_change &&
			    memcmp(fs_devices->metadata_uuid,
				   fs_devices->fsid, BTRFS_FSID_SIZE) != 0 &&
			    memcmp(metadata_fsid, fs_devices->metadata_uuid,
				   BTRFS_FSID_SIZE) == 0) {
				return fs_devices;
			}
		}
	}

	/* Handle non-split brain cases */
	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
		if (metadata_fsid) {
			if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0
			    && memcmp(metadata_fsid, fs_devices->metadata_uuid,
				      BTRFS_FSID_SIZE) == 0)
				return fs_devices;
		} else {
			if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
				return fs_devices;
		}
	}
	return NULL;
}

Project: linux
File: volumes.c

int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
{
	struct btrfs_balance_control *bctl;
	struct btrfs_balance_item *item;
	struct btrfs_disk_balance_args disk_bargs;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_key key;
	int ret;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	key.objectid = BTRFS_BALANCE_OBJECTID;
	key.type = BTRFS_TEMPORARY_ITEM_KEY;
	key.offset = 0;

	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
	if (ret > 0) { /* ret = -ENOENT; */
		ret = 0;
		goto out;
	}

	bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
	if (!bctl) {
		ret = -ENOMEM;
		goto out;
	}

	leaf = path->nodes[0];
	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);

	bctl->flags = btrfs_balance_flags(leaf, item);
	bctl->flags |= BTRFS_BALANCE_RESUME;

	btrfs_balance_data(leaf, item, &disk_bargs);
	btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
	btrfs_balance_meta(leaf, item, &disk_bargs);
	btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
	btrfs_balance_sys(leaf, item, &disk_bargs);
	btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);

	/*
	 * This should never happen, as the paused balance state is recovered
	 * during mount without any chance of other exclusive ops to collide.
	 *
	 * This gives the exclusive op status to balance and keeps in paused
	 * state until user intervention (cancel or umount). If the ownership
	 * cannot be assigned, show a message but do not fail. The balance
	 * is in a paused state and must have fs_info::balance_ctl properly
	 * set up.
	 */
	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
		btrfs_warn(fs_info,
	"balance: cannot set exclusive op status, resume manually");

	mutex_lock(&fs_info->balance_mutex);
	BUG_ON(fs_info->balance_ctl);
	spin_lock(&fs_info->balance_lock);
	fs_info->balance_ctl = bctl;
	spin_unlock(&fs_info->balance_lock);
	mutex_unlock(&fs_info->balance_mutex);
out:
	btrfs_free_path(path);
	return ret;
}

Project: linux
File: scrub.c

static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
{
	scrub_pause_on(fs_info);
	scrub_pause_off(fs_info);
}

Project: linux
File: ioctl.c

static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
{
	struct btrfs_ioctl_ino_lookup_user_args *args;
	struct inode *inode;
	int ret;

	args = memdup_user(argp, sizeof(*args));
	if (IS_ERR(args))
		return PTR_ERR(args);

	inode = file_inode(file);

	if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
	    BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
		/*
		 * The subvolume does not exist under fd with which this is
		 * called
		 */
		kfree(args);
		return -EACCES;
	}

	ret = btrfs_search_path_in_tree_user(inode, args);

	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
		ret = -EFAULT;

	kfree(args);
	return ret;
}

Project: linux
File: scrub.c

static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
						  u64 start, u64 len)
{
	__scrub_mark_bitmap(sparity, sparity->dbitmap, start, len);
}

Project: linux
File: volumes.c

static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
			       struct btrfs_fs_info *fs_info)
{
	struct btrfs_root *root = fs_info->chunk_root;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_dev_item *dev_item;
	struct btrfs_device *device;
	struct btrfs_key key;
	u8 fs_uuid[BTRFS_FSID_SIZE];
	u8 dev_uuid[BTRFS_UUID_SIZE];
	u64 devid;
	int ret;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
	key.offset = 0;
	key.type = BTRFS_DEV_ITEM_KEY;

	while (1) {
		ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
		if (ret < 0)
			goto error;

		leaf = path->nodes[0];
next_slot:
		if (path->slots[0] >= btrfs_header_nritems(leaf)) {
			ret = btrfs_next_leaf(root, path);
			if (ret > 0)
				break;
			if (ret < 0)
				goto error;
			leaf = path->nodes[0];
			btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
			btrfs_release_path(path);
			continue;
		}

		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
		if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
		    key.type != BTRFS_DEV_ITEM_KEY)
			break;

		dev_item = btrfs_item_ptr(leaf, path->slots[0],
					  struct btrfs_dev_item);
		devid = btrfs_device_id(leaf, dev_item);
		read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
				   BTRFS_UUID_SIZE);
		read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
				   BTRFS_FSID_SIZE);
		device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
					   fs_uuid, true);
		BUG_ON(!device); /* Logic error */

		if (device->fs_devices->seeding) {
			btrfs_set_device_generation(leaf, dev_item,
						    device->generation);
			btrfs_mark_buffer_dirty(leaf);
		}

		path->slots[0]++;
		goto next_slot;
	}
	ret = 0;
error:
	btrfs_free_path(path);
	return ret;
}

Project: linux
File: ioctl.c

static void clone_update_extent_map(struct btrfs_inode *inode,
				    const struct btrfs_trans_handle *trans,
				    const struct btrfs_path *path,
				    const u64 hole_offset,
				    const u64 hole_len)
{
	struct extent_map_tree *em_tree = &inode->extent_tree;
	struct extent_map *em;
	int ret;

	em = alloc_extent_map();
	if (!em) {
		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
		return;
	}

	if (path) {
		struct btrfs_file_extent_item *fi;

		fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
				    struct btrfs_file_extent_item);
		btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
		em->generation = -1;
		if (btrfs_file_extent_type(path->nodes[0], fi) ==
		    BTRFS_FILE_EXTENT_INLINE)
			set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
					&inode->runtime_flags);
	} else {
		em->start = hole_offset;
		em->len = hole_len;
		em->ram_bytes = em->len;
		em->orig_start = hole_offset;
		em->block_start = EXTENT_MAP_HOLE;
		em->block_len = 0;
		em->orig_block_len = 0;
		em->compress_type = BTRFS_COMPRESS_NONE;
		em->generation = trans->transid;
	}

	while (1) {
		write_lock(&em_tree->lock);
		ret = add_extent_mapping(em_tree, em, 1);
		write_unlock(&em_tree->lock);
		if (ret != -EEXIST) {
			free_extent_map(em);
			break;
		}
		btrfs_drop_extent_cache(inode, em->start,
					em->start + em->len - 1, 0);
	}

	if (ret)
		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
}

Project: linux
File: scrub.c

static inline void scrub_put_recover(struct btrfs_fs_info *fs_info,
				     struct scrub_recover *recover)
{
	if (refcount_dec_and_test(&recover->refs)) {
		btrfs_bio_counter_dec(fs_info);
		btrfs_put_bbio(recover->bbio);
		kfree(recover);
	}
}

Project: linux
File: ioctl.c

static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
				 void __user *arg)
{
	struct btrfs_ioctl_dev_info_args *di_args;
	struct btrfs_device *dev;
	int ret = 0;
	char *s_uuid = NULL;

	di_args = memdup_user(arg, sizeof(*di_args));
	if (IS_ERR(di_args))
		return PTR_ERR(di_args);

	if (!btrfs_is_empty_uuid(di_args->uuid))
		s_uuid = di_args->uuid;

	rcu_read_lock();
	dev = btrfs_find_device(fs_info->fs_devices, di_args->devid, s_uuid,
				NULL, true);

	if (!dev) {
		ret = -ENODEV;
		goto out;
	}

	di_args->devid = dev->devid;
	di_args->bytes_used = btrfs_device_get_bytes_used(dev);
	di_args->total_bytes = btrfs_device_get_total_bytes(dev);
	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
	if (dev->name) {
		strncpy(di_args->path, rcu_str_deref(dev->name),
				sizeof(di_args->path) - 1);
		di_args->path[sizeof(di_args->path) - 1] = 0;
	} else {
		di_args->path[0] = '\0';
	}

out:
	rcu_read_unlock();
	if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
		ret = -EFAULT;

	kfree(di_args);
	return ret;
}

Project: linux
File: scrub.c

static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
				     struct scrub_block *sblocks_for_recheck)
{
	struct scrub_ctx *sctx = original_sblock->sctx;
	struct btrfs_fs_info *fs_info = sctx->fs_info;
	u64 length = original_sblock->page_count * PAGE_SIZE;
	u64 logical = original_sblock->pagev[0]->logical;
	u64 generation = original_sblock->pagev[0]->generation;
	u64 flags = original_sblock->pagev[0]->flags;
	u64 have_csum = original_sblock->pagev[0]->have_csum;
	struct scrub_recover *recover;
	struct btrfs_bio *bbio;
	u64 sublen;
	u64 mapped_length;
	u64 stripe_offset;
	int stripe_index;
	int page_index = 0;
	int mirror_index;
	int nmirrors;
	int ret;

	/*
	 * note: the two members refs and outstanding_pages
	 * are not used (and not set) in the blocks that are used for
	 * the recheck procedure
	 */

	while (length > 0) {
		sublen = min_t(u64, length, PAGE_SIZE);
		mapped_length = sublen;
		bbio = NULL;

		/*
		 * with a length of PAGE_SIZE, each returned stripe
		 * represents one mirror
		 */
		btrfs_bio_counter_inc_blocked(fs_info);
		ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
				logical, &mapped_length, &bbio);
		if (ret || !bbio || mapped_length < sublen) {
			btrfs_put_bbio(bbio);
			btrfs_bio_counter_dec(fs_info);
			return -EIO;
		}

		recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
		if (!recover) {
			btrfs_put_bbio(bbio);
			btrfs_bio_counter_dec(fs_info);
			return -ENOMEM;
		}

		refcount_set(&recover->refs, 1);
		recover->bbio = bbio;
		recover->map_length = mapped_length;

		BUG_ON(page_index >= SCRUB_MAX_PAGES_PER_BLOCK);

		nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);

		for (mirror_index = 0; mirror_index < nmirrors;
		     mirror_index++) {
			struct scrub_block *sblock;
			struct scrub_page *page;

			sblock = sblocks_for_recheck + mirror_index;
			sblock->sctx = sctx;

			page = kzalloc(sizeof(*page), GFP_NOFS);
			if (!page) {
leave_nomem:
				spin_lock(&sctx->stat_lock);
				sctx->stat.malloc_errors++;
				spin_unlock(&sctx->stat_lock);
				scrub_put_recover(fs_info, recover);
				return -ENOMEM;
			}
			scrub_page_get(page);
			sblock->pagev[page_index] = page;
			page->sblock = sblock;
			page->flags = flags;
			page->generation = generation;
			page->logical = logical;
			page->have_csum = have_csum;
			if (have_csum)
				memcpy(page->csum,
				       original_sblock->pagev[0]->csum,
				       sctx->csum_size);

			scrub_stripe_index_and_offset(logical,
						      bbio->map_type,
						      bbio->raid_map,
						      mapped_length,
						      bbio->num_stripes -
						      bbio->num_tgtdevs,
						      mirror_index,
						      &stripe_index,
						      &stripe_offset);
			page->physical = bbio->stripes[stripe_index].physical +
					 stripe_offset;
			page->dev = bbio->stripes[stripe_index].dev;

			BUG_ON(page_index >= original_sblock->page_count);
			page->physical_for_dev_replace =
				original_sblock->pagev[page_index]->
				physical_for_dev_replace;
			/* for missing devices, dev->bdev is NULL */
			page->mirror_num = mirror_index + 1;
			sblock->page_count++;
			page->page = alloc_page(GFP_NOFS);
			if (!page->page)
				goto leave_nomem;

			scrub_get_recover(recover);
			page->recover = recover;
		}
		scrub_put_recover(fs_info, recover);
		length -= sublen;
		logical += sublen;
		page_index++;
	}

	return 0;
}

Project: linux
File: volumes.c

static void describe_balance_args(struct btrfs_balance_args *bargs, char *buf,
				 u32 size_buf)
{
	int ret;
	u32 size_bp = size_buf;
	char *bp = buf;
	u64 flags = bargs->flags;
	char tmp_buf[128] = {'\0'};

	if (!flags)
		return;

#define CHECK_APPEND_NOARG(a)						\
	do {								\
		ret = snprintf(bp, size_bp, (a));			\
		if (ret < 0 || ret >= size_bp)				\
			goto out_overflow;				\
		size_bp -= ret;						\
		bp += ret;						\
	} while (0)

#define CHECK_APPEND_1ARG(a, v1)					\
	do {								\
		ret = snprintf(bp, size_bp, (a), (v1));			\
		if (ret < 0 || ret >= size_bp)				\
			goto out_overflow;				\
		size_bp -= ret;						\
		bp += ret;						\
	} while (0)

#define CHECK_APPEND_2ARG(a, v1, v2)					\
	do {								\
		ret = snprintf(bp, size_bp, (a), (v1), (v2));		\
		if (ret < 0 || ret >= size_bp)				\
			goto out_overflow;				\
		size_bp -= ret;						\
		bp += ret;						\
	} while (0)

	if (flags & BTRFS_BALANCE_ARGS_CONVERT) {
		int index = btrfs_bg_flags_to_raid_index(bargs->target);

		CHECK_APPEND_1ARG("convert=%s,", get_raid_name(index));
	}

	if (flags & BTRFS_BALANCE_ARGS_SOFT)
		CHECK_APPEND_NOARG("soft,");

	if (flags & BTRFS_BALANCE_ARGS_PROFILES) {
		btrfs_describe_block_groups(bargs->profiles, tmp_buf,
					    sizeof(tmp_buf));
		CHECK_APPEND_1ARG("profiles=%s,", tmp_buf);
	}

	if (flags & BTRFS_BALANCE_ARGS_USAGE)
		CHECK_APPEND_1ARG("usage=%llu,", bargs->usage);

	if (flags & BTRFS_BALANCE_ARGS_USAGE_RANGE)
		CHECK_APPEND_2ARG("usage=%u..%u,",
				  bargs->usage_min, bargs->usage_max);

	if (flags & BTRFS_BALANCE_ARGS_DEVID)
		CHECK_APPEND_1ARG("devid=%llu,", bargs->devid);

	if (flags & BTRFS_BALANCE_ARGS_DRANGE)
		CHECK_APPEND_2ARG("drange=%llu..%llu,",
				  bargs->pstart, bargs->pend);

	if (flags & BTRFS_BALANCE_ARGS_VRANGE)
		CHECK_APPEND_2ARG("vrange=%llu..%llu,",
				  bargs->vstart, bargs->vend);

	if (flags & BTRFS_BALANCE_ARGS_LIMIT)
		CHECK_APPEND_1ARG("limit=%llu,", bargs->limit);

	if (flags & BTRFS_BALANCE_ARGS_LIMIT_RANGE)
		CHECK_APPEND_2ARG("limit=%u..%u,",
				bargs->limit_min, bargs->limit_max);

	if (flags & BTRFS_BALANCE_ARGS_STRIPES_RANGE)
		CHECK_APPEND_2ARG("stripes=%u..%u,",
				  bargs->stripes_min, bargs->stripes_max);

#undef CHECK_APPEND_2ARG
#undef CHECK_APPEND_1ARG
#undef CHECK_APPEND_NOARG

out_overflow:

	if (size_bp < size_buf)
		buf[size_buf - size_bp - 1] = '\0'; /* remove last , */
	else
		buf[0] = '\0';
}

Project: linux
File: volumes.c

static int btrfs_free_stale_devices(const char *path,
				     struct btrfs_device *skip_device)
{
	struct btrfs_fs_devices *fs_devices, *tmp_fs_devices;
	struct btrfs_device *device, *tmp_device;
	int ret = 0;

	if (path)
		ret = -ENOENT;

	list_for_each_entry_safe(fs_devices, tmp_fs_devices, &fs_uuids, fs_list) {

		mutex_lock(&fs_devices->device_list_mutex);
		list_for_each_entry_safe(device, tmp_device,
					 &fs_devices->devices, dev_list) {
			if (skip_device && skip_device == device)
				continue;
			if (path && !device->name)
				continue;
			if (path && !device_path_matched(path, device))
				continue;
			if (fs_devices->opened) {
				/* for an already deleted device return 0 */
				if (path && ret != 0)
					ret = -EBUSY;
				break;
			}

			/* delete the stale device */
			fs_devices->num_devices--;
			list_del(&device->dev_list);
			btrfs_free_device(device);

			ret = 0;
			if (fs_devices->num_devices == 0)
				break;
		}
		mutex_unlock(&fs_devices->device_list_mutex);

		if (fs_devices->num_devices == 0) {
			btrfs_sysfs_remove_fsid(fs_devices);
			list_del(&fs_devices->fs_list);
			free_fs_devices(fs_devices);
		}
	}

	return ret;
}

Project: linux
File: volumes.c

static int __btrfs_balance(struct btrfs_fs_info *fs_info)
{
	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
	struct btrfs_root *chunk_root = fs_info->chunk_root;
	u64 chunk_type;
	struct btrfs_chunk *chunk;
	struct btrfs_path *path = NULL;
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct extent_buffer *leaf;
	int slot;
	int ret;
	int enospc_errors = 0;
	bool counting = true;
	/* The single value limit and min/max limits use the same bytes in the */
	u64 limit_data = bctl->data.limit;
	u64 limit_meta = bctl->meta.limit;
	u64 limit_sys = bctl->sys.limit;
	u32 count_data = 0;
	u32 count_meta = 0;
	u32 count_sys = 0;
	int chunk_reserved = 0;

	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto error;
	}

	/* zero out stat counters */
	spin_lock(&fs_info->balance_lock);
	memset(&bctl->stat, 0, sizeof(bctl->stat));
	spin_unlock(&fs_info->balance_lock);
again:
	if (!counting) {
		/*
		 * The single value limit and min/max limits use the same bytes
		 * in the
		 */
		bctl->data.limit = limit_data;
		bctl->meta.limit = limit_meta;
		bctl->sys.limit = limit_sys;
	}
	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
	key.offset = (u64)-1;
	key.type = BTRFS_CHUNK_ITEM_KEY;

	while (1) {
		if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
		    atomic_read(&fs_info->balance_cancel_req)) {
			ret = -ECANCELED;
			goto error;
		}

		mutex_lock(&fs_info->delete_unused_bgs_mutex);
		ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
		if (ret < 0) {
			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
			goto error;
		}

		/*
		 * this shouldn't happen, it means the last relocate
		 * failed
		 */
		if (ret == 0)
			BUG(); /* FIXME break ? */

		ret = btrfs_previous_item(chunk_root, path, 0,
					  BTRFS_CHUNK_ITEM_KEY);
		if (ret) {
			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
			ret = 0;
			break;
		}

		leaf = path->nodes[0];
		slot = path->slots[0];
		btrfs_item_key_to_cpu(leaf, &found_key, slot);

		if (found_key.objectid != key.objectid) {
			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
			break;
		}

		chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
		chunk_type = btrfs_chunk_type(leaf, chunk);

		if (!counting) {
			spin_lock(&fs_info->balance_lock);
			bctl->stat.considered++;
			spin_unlock(&fs_info->balance_lock);
		}

		ret = should_balance_chunk(fs_info, leaf, chunk,
					   found_key.offset);

		btrfs_release_path(path);
		if (!ret) {
			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
			goto loop;
		}

		if (counting) {
			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
			spin_lock(&fs_info->balance_lock);
			bctl->stat.expected++;
			spin_unlock(&fs_info->balance_lock);

			if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
				count_data++;
			else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
				count_sys++;
			else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
				count_meta++;

			goto loop;
		}

		/*
		 * Apply limit_min filter, no need to check if the LIMITS
		 * filter is used, limit_min is 0 by default
		 */
		if (((chunk_type & BTRFS_BLOCK_GROUP_DATA) &&
					count_data < bctl->data.limit_min)
				|| ((chunk_type & BTRFS_BLOCK_GROUP_METADATA) &&
					count_meta < bctl->meta.limit_min)
				|| ((chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) &&
					count_sys < bctl->sys.limit_min)) {
			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
			goto loop;
		}

		if (!chunk_reserved) {
			/*
			 * We may be relocating the only data chunk we have,
			 * which could potentially end up with losing data's
			 * raid profile, so lets allocate an empty one in
			 * advance.
			 */
			ret = btrfs_may_alloc_data_chunk(fs_info,
							 found_key.offset);
			if (ret < 0) {
				mutex_unlock(&fs_info->delete_unused_bgs_mutex);
				goto error;
			} else if (ret == 1) {
				chunk_reserved = 1;
			}
		}

		ret = btrfs_relocate_chunk(fs_info, found_key.offset);
		mutex_unlock(&fs_info->delete_unused_bgs_mutex);
		if (ret == -ENOSPC) {
			enospc_errors++;
		} else if (ret == -ETXTBSY) {
			btrfs_info(fs_info,
	   "skipping relocation of block group %llu due to active swapfile",
				   found_key.offset);
			ret = 0;
		} else if (ret) {
			goto error;
		} else {
			spin_lock(&fs_info->balance_lock);
			bctl->stat.completed++;
			spin_unlock(&fs_info->balance_lock);
		}
loop:
		if (found_key.offset == 0)
			break;
		key.offset = found_key.offset - 1;
	}

	if (counting) {
		btrfs_release_path(path);
		counting = false;
		goto again;
	}
error:
	btrfs_free_path(path);
	if (enospc_errors) {
		btrfs_info(fs_info, "%d enospc errors during balance",
			   enospc_errors);
		if (!ret)
			ret = -ENOSPC;
	}

	return ret;
}

Project: linux
File: ioctl.c

static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
{
	struct inode *inode = file_inode(file);
	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_ioctl_qgroup_assign_args *sa;
	struct btrfs_trans_handle *trans;
	int ret;
	int err;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	ret = mnt_want_write_file(file);
	if (ret)
		return ret;

	sa = memdup_user(arg, sizeof(*sa));
	if (IS_ERR(sa)) {
		ret = PTR_ERR(sa);
		goto drop_write;
	}

	trans = btrfs_join_transaction(root);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		goto out;
	}

	if (sa->assign) {
		ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
	} else {
		ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
	}

	/* update qgroup status and info */
	err = btrfs_run_qgroups(trans);
	if (err < 0)
		btrfs_handle_fs_error(fs_info, err,
				      "failed to update qgroup status and info");
	err = btrfs_end_transaction(trans);
	if (err && !ret)
		ret = err;

out:
	kfree(sa);
drop_write:
	mnt_drop_write_file(file);
	return ret;
}

Project: linux
File: scrub.c

static int scrub_checksum_tree_block(struct scrub_block *sblock)
{
	struct scrub_ctx *sctx = sblock->sctx;
	struct btrfs_header *h;
	struct btrfs_fs_info *fs_info = sctx->fs_info;
	u8 calculated_csum[BTRFS_CSUM_SIZE];
	u8 on_disk_csum[BTRFS_CSUM_SIZE];
	struct page *page;
	void *mapped_buffer;
	u64 mapped_size;
	void *p;
	u32 crc = ~(u32)0;
	u64 len;
	int index;

	BUG_ON(sblock->page_count < 1);
	page = sblock->pagev[0]->page;
	mapped_buffer = kmap_atomic(page);
	h = (struct btrfs_header *)mapped_buffer;
	memcpy(on_disk_csum, h->csum, sctx->csum_size);

	/*
	 * we don't use the getter functions here, as we
	 * a) don't have an extent buffer and
	 * b) the page is already kmapped
	 */
	if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
		sblock->header_error = 1;

	if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h)) {
		sblock->header_error = 1;
		sblock->generation_error = 1;
	}

	if (!scrub_check_fsid(h->fsid, sblock->pagev[0]))
		sblock->header_error = 1;

	if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
		   BTRFS_UUID_SIZE))
		sblock->header_error = 1;

	len = sctx->fs_info->nodesize - BTRFS_CSUM_SIZE;
	mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
	p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
	index = 0;
	for (;;) {
		u64 l = min_t(u64, len, mapped_size);

		crc = btrfs_csum_data(p, crc, l);
		kunmap_atomic(mapped_buffer);
		len -= l;
		if (len == 0)
			break;
		index++;
		BUG_ON(index >= sblock->page_count);
		BUG_ON(!sblock->pagev[index]->page);
		page = sblock->pagev[index]->page;
		mapped_buffer = kmap_atomic(page);
		mapped_size = PAGE_SIZE;
		p = mapped_buffer;
	}

	btrfs_csum_final(crc, calculated_csum);
	if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
		sblock->checksum_error = 1;

	return sblock->header_error || sblock->checksum_error;
}

Project: linux
File: ioctl.c

static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
{
	struct inode *inode = file_inode(file);
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_ioctl_qgroup_create_args *sa;
	struct btrfs_trans_handle *trans;
	int ret;
	int err;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	ret = mnt_want_write_file(file);
	if (ret)
		return ret;

	sa = memdup_user(arg, sizeof(*sa));
	if (IS_ERR(sa)) {
		ret = PTR_ERR(sa);
		goto drop_write;
	}

	if (!sa->qgroupid) {
		ret = -EINVAL;
		goto out;
	}

	trans = btrfs_join_transaction(root);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		goto out;
	}

	if (sa->create) {
		ret = btrfs_create_qgroup(trans, sa->qgroupid);
	} else {
		ret = btrfs_remove_qgroup(trans, sa->qgroupid);
	}

	err = btrfs_end_transaction(trans);
	if (err && !ret)
		ret = err;

out:
	kfree(sa);
drop_write:
	mnt_drop_write_file(file);
	return ret;
}

Project: linux
File: scrub.c

int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
			   struct btrfs_device *dev)
{
	struct scrub_ctx *sctx;

	mutex_lock(&fs_info->scrub_lock);
	sctx = dev->scrub_ctx;
	if (!sctx) {
		mutex_unlock(&fs_info->scrub_lock);
		return -ENOTCONN;
	}
	atomic_inc(&sctx->cancel_req);
	while (dev->scrub_ctx) {
		mutex_unlock(&fs_info->scrub_lock);
		wait_event(fs_info->scrub_pause_wait,
			   dev->scrub_ctx == NULL);
		mutex_lock(&fs_info->scrub_lock);
	}
	mutex_unlock(&fs_info->scrub_lock);

	return 0;
}

Project: linux
File: scrub.c

static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
					   struct map_lookup *map,
					   struct btrfs_device *scrub_dev,
					   int num, u64 base, u64 length)
{
	struct btrfs_path *path, *ppath;
	struct btrfs_fs_info *fs_info = sctx->fs_info;
	struct btrfs_root *root = fs_info->extent_root;
	struct btrfs_root *csum_root = fs_info->csum_root;
	struct btrfs_extent_item *extent;
	struct blk_plug plug;
	u64 flags;
	int ret;
	int slot;
	u64 nstripes;
	struct extent_buffer *l;
	u64 physical;
	u64 logical;
	u64 logic_end;
	u64 physical_end;
	u64 generation;
	int mirror_num;
	struct reada_control *reada1;
	struct reada_control *reada2;
	struct btrfs_key key;
	struct btrfs_key key_end;
	u64 increment = map->stripe_len;
	u64 offset;
	u64 extent_logical;
	u64 extent_physical;
	u64 extent_len;
	u64 stripe_logical;
	u64 stripe_end;
	struct btrfs_device *extent_dev;
	int extent_mirror_num;
	int stop_loop = 0;

	physical = map->stripes[num].physical;
	offset = 0;
	nstripes = div64_u64(length, map->stripe_len);
	if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
		offset = map->stripe_len * num;
		increment = map->stripe_len * map->num_stripes;
		mirror_num = 1;
	} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
		int factor = map->num_stripes / map->sub_stripes;
		offset = map->stripe_len * (num / map->sub_stripes);
		increment = map->stripe_len * factor;
		mirror_num = num % map->sub_stripes + 1;
	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
		increment = map->stripe_len;
		mirror_num = num % map->num_stripes + 1;
	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
		increment = map->stripe_len;
		mirror_num = num % map->num_stripes + 1;
	} else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
		get_raid56_logic_offset(physical, num, map, &offset, NULL);
		increment = map->stripe_len * nr_data_stripes(map);
		mirror_num = 1;
	} else {
		increment = map->stripe_len;
		mirror_num = 1;
	}

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	ppath = btrfs_alloc_path();
	if (!ppath) {
		btrfs_free_path(path);
		return -ENOMEM;
	}

	/*
	 * work on commit root. The related disk blocks are static as
	 * long as COW is applied. This means, it is save to rewrite
	 * them to repair disk errors without any race conditions
	 */
	path->search_commit_root = 1;
	path->skip_locking = 1;

	ppath->search_commit_root = 1;
	ppath->skip_locking = 1;
	/*
	 * trigger the readahead for extent tree csum tree and wait for
	 * completion. During readahead, the scrub is officially paused
	 * to not hold off transaction commits
	 */
	logical = base + offset;
	physical_end = physical + nstripes * map->stripe_len;
	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
		get_raid56_logic_offset(physical_end, num,
					map, &logic_end, NULL);
		logic_end += base;
	} else {
		logic_end = logical + increment * nstripes;
	}
	wait_event(sctx->list_wait,
		   atomic_read(&sctx->bios_in_flight) == 0);
	scrub_blocked_if_needed(fs_info);

	/* FIXME it might be better to start readahead at commit root */
	key.objectid = logical;
	key.type = BTRFS_EXTENT_ITEM_KEY;
	key.offset = (u64)0;
	key_end.objectid = logic_end;
	key_end.type = BTRFS_METADATA_ITEM_KEY;
	key_end.offset = (u64)-1;
	reada1 = btrfs_reada_add(root, &key, &key_end);

	key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
	key.type = BTRFS_EXTENT_CSUM_KEY;
	key.offset = logical;
	key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
	key_end.type = BTRFS_EXTENT_CSUM_KEY;
	key_end.offset = logic_end;
	reada2 = btrfs_reada_add(csum_root, &key, &key_end);

	if (!IS_ERR(reada1))
		btrfs_reada_wait(reada1);
	if (!IS_ERR(reada2))
		btrfs_reada_wait(reada2);


	/*
	 * collect all data csums for the stripe to avoid seeking during
	 * the scrub. This might currently (crc32) end up to be about 1MB
	 */
	blk_start_plug(&plug);

	/*
	 * now find all extents for each stripe and scrub them
	 */
	ret = 0;
	while (physical < physical_end) {
		/*
		 * canceled?
		 */
		if (atomic_read(&fs_info->scrub_cancel_req) ||
		    atomic_read(&sctx->cancel_req)) {
			ret = -ECANCELED;
			goto out;
		}
		/*
		 * check to see if we have to pause
		 */
		if (atomic_read(&fs_info->scrub_pause_req)) {
			/* push queued extents */
			sctx->flush_all_writes = true;
			scrub_submit(sctx);
			mutex_lock(&sctx->wr_lock);
			scrub_wr_submit(sctx);
			mutex_unlock(&sctx->wr_lock);
			wait_event(sctx->list_wait,
				   atomic_read(&sctx->bios_in_flight) == 0);
			sctx->flush_all_writes = false;
			scrub_blocked_if_needed(fs_info);
		}

		if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
			ret = get_raid56_logic_offset(physical, num, map,
						      &logical,
						      &stripe_logical);
			logical += base;
			if (ret) {
				/* it is parity strip */
				stripe_logical += base;
				stripe_end = stripe_logical + increment;
				ret = scrub_raid56_parity(sctx, map, scrub_dev,
							  ppath, stripe_logical,
							  stripe_end);
				if (ret)
					goto out;
				goto skip;
			}
		}

		if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
			key.type = BTRFS_METADATA_ITEM_KEY;
		else
			key.type = BTRFS_EXTENT_ITEM_KEY;
		key.objectid = logical;
		key.offset = (u64)-1;

		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		if (ret < 0)
			goto out;

		if (ret > 0) {
			ret = btrfs_previous_extent_item(root, path, 0);
			if (ret < 0)
				goto out;
			if (ret > 0) {
				/* there's no smaller item, so stick with the
				 * larger one */
				btrfs_release_path(path);
				ret = btrfs_search_slot(NULL, root, &key,
							path, 0, 0);
				if (ret < 0)
					goto out;
			}
		}

		stop_loop = 0;
		while (1) {
			u64 bytes;

			l = path->nodes[0];
			slot = path->slots[0];
			if (slot >= btrfs_header_nritems(l)) {
				ret = btrfs_next_leaf(root, path);
				if (ret == 0)
					continue;
				if (ret < 0)
					goto out;

				stop_loop = 1;
				break;
			}
			btrfs_item_key_to_cpu(l, &key, slot);

			if (key.type != BTRFS_EXTENT_ITEM_KEY &&
			    key.type != BTRFS_METADATA_ITEM_KEY)
				goto next;

			if (key.type == BTRFS_METADATA_ITEM_KEY)
				bytes = fs_info->nodesize;
			else
				bytes = key.offset;

			if (key.objectid + bytes <= logical)
				goto next;

			if (key.objectid >= logical + map->stripe_len) {
				/* out of this device extent */
				if (key.objectid >= logic_end)
					stop_loop = 1;
				break;
			}

			extent = btrfs_item_ptr(l, slot,
						struct btrfs_extent_item);
			flags = btrfs_extent_flags(l, extent);
			generation = btrfs_extent_generation(l, extent);

			if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
			    (key.objectid < logical ||
			     key.objectid + bytes >
			     logical + map->stripe_len)) {
				btrfs_err(fs_info,
					   "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
				       key.objectid, logical);
				spin_lock(&sctx->stat_lock);
				sctx->stat.uncorrectable_errors++;
				spin_unlock(&sctx->stat_lock);
				goto next;
			}

again:
			extent_logical = key.objectid;
			extent_len = bytes;

			/*
			 * trim extent to this stripe
			 */
			if (extent_logical < logical) {
				extent_len -= logical - extent_logical;
				extent_logical = logical;
			}
			if (extent_logical + extent_len >
			    logical + map->stripe_len) {
				extent_len = logical + map->stripe_len -
					     extent_logical;
			}

			extent_physical = extent_logical - logical + physical;
			extent_dev = scrub_dev;
			extent_mirror_num = mirror_num;
			if (sctx->is_dev_replace)
				scrub_remap_extent(fs_info, extent_logical,
						   extent_len, &extent_physical,
						   &extent_dev,
						   &extent_mirror_num);

			ret = btrfs_lookup_csums_range(csum_root,
						       extent_logical,
						       extent_logical +
						       extent_len - 1,
						       &sctx->csum_list, 1);
			if (ret)
				goto out;

			ret = scrub_extent(sctx, map, extent_logical, extent_len,
					   extent_physical, extent_dev, flags,
					   generation, extent_mirror_num,
					   extent_logical - logical + physical);

			scrub_free_csums(sctx);

			if (ret)
				goto out;

			if (extent_logical + extent_len <
			    key.objectid + bytes) {
				if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
					/*
					 * loop until we find next data stripe
					 * or we have finished all stripes.
					 */
loop:
					physical += map->stripe_len;
					ret = get_raid56_logic_offset(physical,
							num, map, &logical,
							&stripe_logical);
					logical += base;

					if (ret && physical < physical_end) {
						stripe_logical += base;
						stripe_end = stripe_logical +
								increment;
						ret = scrub_raid56_parity(sctx,
							map, scrub_dev, ppath,
							stripe_logical,
							stripe_end);
						if (ret)
							goto out;
						goto loop;
					}
				} else {
					physical += map->stripe_len;
					logical += increment;
				}
				if (logical < key.objectid + bytes) {
					cond_resched();
					goto again;
				}

				if (physical >= physical_end) {
					stop_loop = 1;
					break;
				}
			}
next:
			path->slots[0]++;
		}
		btrfs_release_path(path);
skip:
		logical += increment;
		physical += map->stripe_len;
		spin_lock(&sctx->stat_lock);
		if (stop_loop)
			sctx->stat.last_physical = map->stripes[num].physical +
						   length;
		else
			sctx->stat.last_physical = physical;
		spin_unlock(&sctx->stat_lock);
		if (stop_loop)
			break;
	}
out:
	/* push queued extents */
	scrub_submit(sctx);
	mutex_lock(&sctx->wr_lock);
	scrub_wr_submit(sctx);
	mutex_unlock(&sctx->wr_lock);

	blk_finish_plug(&plug);
	btrfs_free_path(path);
	btrfs_free_path(ppath);
	return ret < 0 ? ret : 0;
}

Project: linux
File: volumes.c

static void pending_bios_fn(struct btrfs_work *work)
{
	struct btrfs_device *device;

	device = container_of(work, struct btrfs_device, work);
	run_scheduled_bios(device);
}

Project: linux
File: volumes.c

int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info)
{
	struct btrfs_root *root = fs_info->chunk_root;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_key key;
	struct btrfs_key found_key;
	int ret;
	int slot;
	u64 total_dev = 0;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	/*
	 * uuid_mutex is needed only if we are mounting a sprout FS
	 * otherwise we don't need it.
	 */
	mutex_lock(&uuid_mutex);
	mutex_lock(&fs_info->chunk_mutex);

	/*
	 * Read all device items, and then all the chunk items. All
	 * device items are found before any chunk item (their object id
	 * is smaller than the lowest possible object id for a chunk
	 * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
	 */
	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
	key.offset = 0;
	key.type = 0;
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto error;
	while (1) {
		leaf = path->nodes[0];
		slot = path->slots[0];
		if (slot >= btrfs_header_nritems(leaf)) {
			ret = btrfs_next_leaf(root, path);
			if (ret == 0)
				continue;
			if (ret < 0)
				goto error;
			break;
		}
		btrfs_item_key_to_cpu(leaf, &found_key, slot);
		if (found_key.type == BTRFS_DEV_ITEM_KEY) {
			struct btrfs_dev_item *dev_item;
			dev_item = btrfs_item_ptr(leaf, slot,
						  struct btrfs_dev_item);
			ret = read_one_dev(fs_info, leaf, dev_item);
			if (ret)
				goto error;
			total_dev++;
		} else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
			struct btrfs_chunk *chunk;
			chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
			ret = read_one_chunk(fs_info, &found_key, leaf, chunk);
			if (ret)
				goto error;
		}
		path->slots[0]++;
	}

	/*
	 * After loading chunk tree, we've got all device information,
	 * do another round of validation checks.
	 */
	if (total_dev != fs_info->fs_devices->total_devices) {
		btrfs_err(fs_info,
	   "super_num_devices %llu mismatch with num_devices %llu found here",
			  btrfs_super_num_devices(fs_info->super_copy),
			  total_dev);
		ret = -EINVAL;
		goto error;
	}
	if (btrfs_super_total_bytes(fs_info->super_copy) <
	    fs_info->fs_devices->total_rw_bytes) {
		btrfs_err(fs_info,
	"super_total_bytes %llu mismatch with fs_devices total_rw_bytes %llu",
			  btrfs_super_total_bytes(fs_info->super_copy),
			  fs_info->fs_devices->total_rw_bytes);
		ret = -EINVAL;
		goto error;
	}
	ret = 0;
error:
	mutex_unlock(&fs_info->chunk_mutex);
	mutex_unlock(&uuid_mutex);

	btrfs_free_path(path);
	return ret;
}

Project: linux
File: ioctl.c

static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
				       void __user *arg)
{
	struct btrfs_ioctl_scrub_args *sa;
	int ret;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	sa = memdup_user(arg, sizeof(*sa));
	if (IS_ERR(sa))
		return PTR_ERR(sa);

	ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);

	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
		ret = -EFAULT;

	kfree(sa);
	return ret;
}

Project: linux
File: ioctl.c

static noinline int create_subvol(struct inode *dir,
				  struct dentry *dentry,
				  const char *name, int namelen,
				  u64 *async_transid,
				  struct btrfs_qgroup_inherit *inherit)
{
	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
	struct btrfs_trans_handle *trans;
	struct btrfs_key key;
	struct btrfs_root_item *root_item;
	struct btrfs_inode_item *inode_item;
	struct extent_buffer *leaf;
	struct btrfs_root *root = BTRFS_I(dir)->root;
	struct btrfs_root *new_root;
	struct btrfs_block_rsv block_rsv;
	struct timespec64 cur_time = current_time(dir);
	struct inode *inode;
	int ret;
	int err;
	u64 objectid;
	u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
	u64 index = 0;
	uuid_le new_uuid;

	root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
	if (!root_item)
		return -ENOMEM;

	ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
	if (ret)
		goto fail_free;

	/*
	 * Don't create subvolume whose level is not zero. Or qgroup will be
	 * screwed up since it assumes subvolume qgroup's level to be 0.
	 */
	if (btrfs_qgroup_level(objectid)) {
		ret = -ENOSPC;
		goto fail_free;
	}

	btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
	/*
	 * The same as the snapshot creation, please see the comment
	 * of create_snapshot().
	 */
	ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
	if (ret)
		goto fail_free;

	trans = btrfs_start_transaction(root, 0);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		btrfs_subvolume_release_metadata(fs_info, &block_rsv);
		goto fail_free;
	}
	trans->block_rsv = &block_rsv;
	trans->bytes_reserved = block_rsv.size;

	ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
	if (ret)
		goto fail;

	leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
	if (IS_ERR(leaf)) {
		ret = PTR_ERR(leaf);
		goto fail;
	}

	btrfs_mark_buffer_dirty(leaf);

	inode_item = &root_item->inode;
	btrfs_set_stack_inode_generation(inode_item, 1);
	btrfs_set_stack_inode_size(inode_item, 3);
	btrfs_set_stack_inode_nlink(inode_item, 1);
	btrfs_set_stack_inode_nbytes(inode_item,
				     fs_info->nodesize);
	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);

	btrfs_set_root_flags(root_item, 0);
	btrfs_set_root_limit(root_item, 0);
	btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);

	btrfs_set_root_bytenr(root_item, leaf->start);
	btrfs_set_root_generation(root_item, trans->transid);
	btrfs_set_root_level(root_item, 0);
	btrfs_set_root_refs(root_item, 1);
	btrfs_set_root_used(root_item, leaf->len);
	btrfs_set_root_last_snapshot(root_item, 0);

	btrfs_set_root_generation_v2(root_item,
			btrfs_root_generation(root_item));
	uuid_le_gen(&new_uuid);
	memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
	btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
	btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
	root_item->ctime = root_item->otime;
	btrfs_set_root_ctransid(root_item, trans->transid);
	btrfs_set_root_otransid(root_item, trans->transid);

	btrfs_tree_unlock(leaf);
	free_extent_buffer(leaf);
	leaf = NULL;

	btrfs_set_root_dirid(root_item, new_dirid);

	key.objectid = objectid;
	key.offset = 0;
	key.type = BTRFS_ROOT_ITEM_KEY;
	ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
				root_item);
	if (ret)
		goto fail;

	key.offset = (u64)-1;
	new_root = btrfs_read_fs_root_no_name(fs_info, &key);
	if (IS_ERR(new_root)) {
		ret = PTR_ERR(new_root);
		btrfs_abort_transaction(trans, ret);
		goto fail;
	}

	btrfs_record_root_in_trans(trans, new_root);

	ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
	if (ret) {
		/* We potentially lose an unused inode item here */
		btrfs_abort_transaction(trans, ret);
		goto fail;
	}

	mutex_lock(&new_root->objectid_mutex);
	new_root->highest_objectid = new_dirid;
	mutex_unlock(&new_root->objectid_mutex);

	/*
	 * insert the directory item
	 */
	ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
	if (ret) {
		btrfs_abort_transaction(trans, ret);
		goto fail;
	}

	ret = btrfs_insert_dir_item(trans, name, namelen, BTRFS_I(dir), &key,
				    BTRFS_FT_DIR, index);
	if (ret) {
		btrfs_abort_transaction(trans, ret);
		goto fail;
	}

	btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
	ret = btrfs_update_inode(trans, root, dir);
	BUG_ON(ret);

	ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid,
				 btrfs_ino(BTRFS_I(dir)), index, name, namelen);
	BUG_ON(ret);

	ret = btrfs_uuid_tree_add(trans, root_item->uuid,
				  BTRFS_UUID_KEY_SUBVOL, objectid);
	if (ret)
		btrfs_abort_transaction(trans, ret);

fail:
	kfree(root_item);
	trans->block_rsv = NULL;
	trans->bytes_reserved = 0;
	btrfs_subvolume_release_metadata(fs_info, &block_rsv);

	if (async_transid) {
		*async_transid = trans->transid;
		err = btrfs_commit_transaction_async(trans, 1);
		if (err)
			err = btrfs_commit_transaction(trans);
	} else {
		err = btrfs_commit_transaction(trans);
	}
	if (err && !ret)
		ret = err;

	if (!ret) {
		inode = btrfs_lookup_dentry(dir, dentry);
		if (IS_ERR(inode))
			return PTR_ERR(inode);
		d_instantiate(dentry, inode);
	}
	return ret;

fail_free:
	kfree(root_item);
	return ret;
}

Project: linux
File: scrub.c

static int lock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
			    bool *locked_ret)
{
	struct btrfs_block_group_cache *bg_cache;
	struct btrfs_full_stripe_locks_tree *locks_root;
	struct full_stripe_lock *existing;
	u64 fstripe_start;
	int ret = 0;

	*locked_ret = false;
	bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
	if (!bg_cache) {
		ASSERT(0);
		return -ENOENT;
	}

	/* Profiles not based on parity don't need full stripe lock */
	if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
		goto out;
	locks_root = &bg_cache->full_stripe_locks_root;

	fstripe_start = get_full_stripe_logical(bg_cache, bytenr);

	/* Now insert the full stripe lock */
	mutex_lock(&locks_root->lock);
	existing = insert_full_stripe_lock(locks_root, fstripe_start);
	mutex_unlock(&locks_root->lock);
	if (IS_ERR(existing)) {
		ret = PTR_ERR(existing);
		goto out;
	}
	mutex_lock(&existing->mutex);
	*locked_ret = true;
out:
	btrfs_put_block_group(bg_cache);
	return ret;
}

Project: linux
File: ioctl.c

loff_t btrfs_remap_file_range(struct file *src_file, loff_t off,
		struct file *dst_file, loff_t destoff, loff_t len,
		unsigned int remap_flags)
{
	struct inode *src_inode = file_inode(src_file);
	struct inode *dst_inode = file_inode(dst_file);
	bool same_inode = dst_inode == src_inode;
	int ret;

	if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
		return -EINVAL;

	ret = btrfs_remap_file_range_prep(src_file, off, dst_file, destoff,
					  &len, remap_flags);
	if (ret < 0 || len == 0)
		return ret;

	if (remap_flags & REMAP_FILE_DEDUP)
		ret = btrfs_extent_same(src_inode, off, len, dst_inode, destoff);
	else
		ret = btrfs_clone_files(dst_file, src_file, off, len, destoff);

	if (same_inode)
		inode_unlock(src_inode);
	else
		btrfs_double_inode_unlock(src_inode, dst_inode);

	return ret < 0 ? ret : len;
}

Project: linux
File: ioctl.c

static int clone_copy_inline_extent(struct inode *dst,
				    struct btrfs_trans_handle *trans,
				    struct btrfs_path *path,
				    struct btrfs_key *new_key,
				    const u64 drop_start,
				    const u64 datal,
				    const u64 skip,
				    const u64 size,
				    char *inline_data)
{
	struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
	struct btrfs_root *root = BTRFS_I(dst)->root;
	const u64 aligned_end = ALIGN(new_key->offset + datal,
				      fs_info->sectorsize);
	int ret;
	struct btrfs_key key;

	if (new_key->offset > 0)
		return -EOPNOTSUPP;

	key.objectid = btrfs_ino(BTRFS_I(dst));
	key.type = BTRFS_EXTENT_DATA_KEY;
	key.offset = 0;
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0) {
		return ret;
	} else if (ret > 0) {
		if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
			ret = btrfs_next_leaf(root, path);
			if (ret < 0)
				return ret;
			else if (ret > 0)
				goto copy_inline_extent;
		}
		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
		if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
		    key.type == BTRFS_EXTENT_DATA_KEY) {
			ASSERT(key.offset > 0);
			return -EOPNOTSUPP;
		}
	} else if (i_size_read(dst) <= datal) {
		struct btrfs_file_extent_item *ei;
		u64 ext_len;

		/*
		 * If the file size is <= datal, make sure there are no other
		 * extents following (can happen do to an fallocate call with
		 * the flag FALLOC_FL_KEEP_SIZE).
		 */
		ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
				    struct btrfs_file_extent_item);
		/*
		 * If it's an inline extent, it can not have other extents
		 * following it.
		 */
		if (btrfs_file_extent_type(path->nodes[0], ei) ==
		    BTRFS_FILE_EXTENT_INLINE)
			goto copy_inline_extent;

		ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
		if (ext_len > aligned_end)
			return -EOPNOTSUPP;

		ret = btrfs_next_item(root, path);
		if (ret < 0) {
			return ret;
		} else if (ret == 0) {
			btrfs_item_key_to_cpu(path->nodes[0], &key,
					      path->slots[0]);
			if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
			    key.type == BTRFS_EXTENT_DATA_KEY)
				return -EOPNOTSUPP;
		}
	}

copy_inline_extent:
	/*
	 * We have no extent items, or we have an extent at offset 0 which may
	 * or may not be inlined. All these cases are dealt the same way.
	 */
	if (i_size_read(dst) > datal) {
		/*
		 * If the destination inode has an inline extent...
		 * This would require copying the data from the source inline
		 * extent into the beginning of the destination's inline extent.
		 * But this is really complex, both extents can be compressed
		 * or just one of them, which would require decompressing and
		 * re-compressing data (which could increase the new compressed
		 * size, not allowing the compressed data to fit anymore in an
		 * inline extent).
		 * So just don't support this case for now (it should be rare,
		 * we are not really saving space when cloning inline extents).
		 */
		return -EOPNOTSUPP;
	}

	btrfs_release_path(path);
	ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
	if (ret)
		return ret;
	ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
	if (ret)
		return ret;

	if (skip) {
		const u32 start = btrfs_file_extent_calc_inline_size(0);

		memmove(inline_data + start, inline_data + start + skip, datal);
	}

	write_extent_buffer(path->nodes[0], inline_data,
			    btrfs_item_ptr_offset(path->nodes[0],
						  path->slots[0]),
			    size);
	inode_add_bytes(dst, datal);

	return 0;
}

Project: linux
File: ioctl.c

static long _btrfs_ioctl_set_received_subvol(struct file *file,
					    struct btrfs_ioctl_received_subvol_args *sa)
{
	struct inode *inode = file_inode(file);
	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_root_item *root_item = &root->root_item;
	struct btrfs_trans_handle *trans;
	struct timespec64 ct = current_time(inode);
	int ret = 0;
	int received_uuid_changed;

	if (!inode_owner_or_capable(inode))
		return -EPERM;

	ret = mnt_want_write_file(file);
	if (ret < 0)
		return ret;

	down_write(&fs_info->subvol_sem);

	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
		ret = -EINVAL;
		goto out;
	}

	if (btrfs_root_readonly(root)) {
		ret = -EROFS;
		goto out;
	}

	/*
	 * 1 - root item
	 * 2 - uuid items (received uuid + subvol uuid)
	 */
	trans = btrfs_start_transaction(root, 3);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		trans = NULL;
		goto out;
	}

	sa->rtransid = trans->transid;
	sa->rtime.sec = ct.tv_sec;
	sa->rtime.nsec = ct.tv_nsec;

	received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
				       BTRFS_UUID_SIZE);
	if (received_uuid_changed &&
	    !btrfs_is_empty_uuid(root_item->received_uuid)) {
		ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
					  root->root_key.objectid);
		if (ret && ret != -ENOENT) {
		        btrfs_abort_transaction(trans, ret);
		        btrfs_end_transaction(trans);
		        goto out;
		}
	}
	memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
	btrfs_set_root_stransid(root_item, sa->stransid);
	btrfs_set_root_rtransid(root_item, sa->rtransid);
	btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
	btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
	btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
	btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);

	ret = btrfs_update_root(trans, fs_info->tree_root,
				&root->root_key, &root->root_item);
	if (ret < 0) {
		btrfs_end_transaction(trans);
		goto out;
	}
	if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
		ret = btrfs_uuid_tree_add(trans, sa->uuid,
					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
					  root->root_key.objectid);
		if (ret < 0 && ret != -EEXIST) {
			btrfs_abort_transaction(trans, ret);
			btrfs_end_transaction(trans);
			goto out;
		}
	}
	ret = btrfs_commit_transaction(trans);
out:
	up_write(&fs_info->subvol_sem);
	mnt_drop_write_file(file);
	return ret;
}

Project: linux
File: ioctl.c

static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
{
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
	struct extent_map *em;
	u64 len = PAGE_SIZE;

	/*
	 * hopefully we have this extent in the tree already, try without
	 * the full extent lock
	 */
	read_lock(&em_tree->lock);
	em = lookup_extent_mapping(em_tree, start, len);
	read_unlock(&em_tree->lock);

	if (!em) {
		struct extent_state *cached = NULL;
		u64 end = start + len - 1;

		/* get the big lock and read metadata off disk */
		lock_extent_bits(io_tree, start, end, &cached);
		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
		unlock_extent_cached(io_tree, start, end, &cached);

		if (IS_ERR(em))
			return NULL;
	}

	return em;
}

Project: linux
File: scrub.c

int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
		    u64 end, struct btrfs_scrub_progress *progress,
		    int readonly, int is_dev_replace)
{
	struct scrub_ctx *sctx;
	int ret;
	struct btrfs_device *dev;
	unsigned int nofs_flag;

	if (btrfs_fs_closing(fs_info))
		return -EINVAL;

	if (fs_info->nodesize > BTRFS_STRIPE_LEN) {
		/*
		 * in this case scrub is unable to calculate the checksum
		 * the way scrub is implemented. Do not handle this
		 * situation at all because it won't ever happen.
		 */
		btrfs_err(fs_info,
			   "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
		       fs_info->nodesize,
		       BTRFS_STRIPE_LEN);
		return -EINVAL;
	}

	if (fs_info->sectorsize != PAGE_SIZE) {
		/* not supported for data w/o checksums */
		btrfs_err_rl(fs_info,
			   "scrub: size assumption sectorsize != PAGE_SIZE (%d != %lu) fails",
		       fs_info->sectorsize, PAGE_SIZE);
		return -EINVAL;
	}

	if (fs_info->nodesize >
	    PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
	    fs_info->sectorsize > PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
		/*
		 * would exhaust the array bounds of pagev member in
		 * struct scrub_block
		 */
		btrfs_err(fs_info,
			  "scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
		       fs_info->nodesize,
		       SCRUB_MAX_PAGES_PER_BLOCK,
		       fs_info->sectorsize,
		       SCRUB_MAX_PAGES_PER_BLOCK);
		return -EINVAL;
	}

	/* Allocate outside of device_list_mutex */
	sctx = scrub_setup_ctx(fs_info, is_dev_replace);
	if (IS_ERR(sctx))
		return PTR_ERR(sctx);

	mutex_lock(&fs_info->fs_devices->device_list_mutex);
	dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
	if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
		     !is_dev_replace)) {
		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
		ret = -ENODEV;
		goto out_free_ctx;
	}

	if (!is_dev_replace && !readonly &&
	    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
		btrfs_err_in_rcu(fs_info, "scrub: device %s is not writable",
				rcu_str_deref(dev->name));
		ret = -EROFS;
		goto out_free_ctx;
	}

	mutex_lock(&fs_info->scrub_lock);
	if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
	    test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) {
		mutex_unlock(&fs_info->scrub_lock);
		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
		ret = -EIO;
		goto out_free_ctx;
	}

	down_read(&fs_info->dev_replace.rwsem);
	if (dev->scrub_ctx ||
	    (!is_dev_replace &&
	     btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
		up_read(&fs_info->dev_replace.rwsem);
		mutex_unlock(&fs_info->scrub_lock);
		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
		ret = -EINPROGRESS;
		goto out_free_ctx;
	}
	up_read(&fs_info->dev_replace.rwsem);

	ret = scrub_workers_get(fs_info, is_dev_replace);
	if (ret) {
		mutex_unlock(&fs_info->scrub_lock);
		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
		goto out_free_ctx;
	}

	sctx->readonly = readonly;
	dev->scrub_ctx = sctx;
	mutex_unlock(&fs_info->fs_devices->device_list_mutex);

	/*
	 * checking @scrub_pause_req here, we can avoid
	 * race between committing transaction and scrubbing.
	 */
	__scrub_blocked_if_needed(fs_info);
	atomic_inc(&fs_info->scrubs_running);
	mutex_unlock(&fs_info->scrub_lock);

	/*
	 * In order to avoid deadlock with reclaim when there is a transaction
	 * trying to pause scrub, make sure we use GFP_NOFS for all the
	 * allocations done at btrfs_scrub_pages() and scrub_pages_for_parity()
	 * invoked by our callees. The pausing request is done when the
	 * transaction commit starts, and it blocks the transaction until scrub
	 * is paused (done at specific points at scrub_stripe() or right above
	 * before incrementing fs_info->scrubs_running).
	 */
	nofs_flag = memalloc_nofs_save();
	if (!is_dev_replace) {
		/*
		 * by holding device list mutex, we can
		 * kick off writing super in log tree sync.
		 */
		mutex_lock(&fs_info->fs_devices->device_list_mutex);
		ret = scrub_supers(sctx, dev);
		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
	}

	if (!ret)
		ret = scrub_enumerate_chunks(sctx, dev, start, end);
	memalloc_nofs_restore(nofs_flag);

	wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
	atomic_dec(&fs_info->scrubs_running);
	wake_up(&fs_info->scrub_pause_wait);

	wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);

	if (progress)
		memcpy(progress, &sctx->stat, sizeof(*progress));

	mutex_lock(&fs_info->scrub_lock);
	dev->scrub_ctx = NULL;
	scrub_workers_put(fs_info);
	mutex_unlock(&fs_info->scrub_lock);

	scrub_put_ctx(sctx);

	return ret;

out_free_ctx:
	scrub_free_ctx(sctx);

	return ret;
}

Project: linux
File: volumes.c

static noinline void run_scheduled_bios(struct btrfs_device *device)
{
	struct btrfs_fs_info *fs_info = device->fs_info;
	struct bio *pending;
	struct backing_dev_info *bdi;
	struct btrfs_pending_bios *pending_bios;
	struct bio *tail;
	struct bio *cur;
	int again = 0;
	unsigned long num_run;
	unsigned long batch_run = 0;
	unsigned long last_waited = 0;
	int force_reg = 0;
	int sync_pending = 0;
	struct blk_plug plug;

	/*
	 * this function runs all the bios we've collected for
	 * a particular device.  We don't want to wander off to
	 * another device without first sending all of these down.
	 * So, setup a plug here and finish it off before we return
	 */
	blk_start_plug(&plug);

	bdi = device->bdev->bd_bdi;

loop:
	spin_lock(&device->io_lock);

loop_lock:
	num_run = 0;

	/* take all the bios off the list at once and process them
	 * later on (without the lock held).  But, remember the
	 * tail and other pointers so the bios can be properly reinserted
	 * into the list if we hit congestion
	 */
	if (!force_reg && device->pending_sync_bios.head) {
		pending_bios = &device->pending_sync_bios;
		force_reg = 1;
	} else {
		pending_bios = &device->pending_bios;
		force_reg = 0;
	}

	pending = pending_bios->head;
	tail = pending_bios->tail;
	WARN_ON(pending && !tail);

	/*
	 * if pending was null this time around, no bios need processing
	 * at all and we can stop.  Otherwise it'll loop back up again
	 * and do an additional check so no bios are missed.
	 *
	 * device->running_pending is used to synchronize with the
	 * schedule_bio code.
	 */
	if (device->pending_sync_bios.head == NULL &&
	    device->pending_bios.head == NULL) {
		again = 0;
		device->running_pending = 0;
	} else {
		again = 1;
		device->running_pending = 1;
	}

	pending_bios->head = NULL;
	pending_bios->tail = NULL;

	spin_unlock(&device->io_lock);

	while (pending) {

		rmb();
		/* we want to work on both lists, but do more bios on the
		 * sync list than the regular list
		 */
		if ((num_run > 32 &&
		    pending_bios != &device->pending_sync_bios &&
		    device->pending_sync_bios.head) ||
		   (num_run > 64 && pending_bios == &device->pending_sync_bios &&
		    device->pending_bios.head)) {
			spin_lock(&device->io_lock);
			requeue_list(pending_bios, pending, tail);
			goto loop_lock;
		}

		cur = pending;
		pending = pending->bi_next;
		cur->bi_next = NULL;

		BUG_ON(atomic_read(&cur->__bi_cnt) == 0);

		/*
		 * if we're doing the sync list, record that our
		 * plug has some sync requests on it
		 *
		 * If we're doing the regular list and there are
		 * sync requests sitting around, unplug before
		 * we add more
		 */
		if (pending_bios == &device->pending_sync_bios) {
			sync_pending = 1;
		} else if (sync_pending) {
			blk_finish_plug(&plug);
			blk_start_plug(&plug);
			sync_pending = 0;
		}

		btrfsic_submit_bio(cur);
		num_run++;
		batch_run++;

		cond_resched();

		/*
		 * we made progress, there is more work to do and the bdi
		 * is now congested.  Back off and let other work structs
		 * run instead
		 */
		if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
		    fs_info->fs_devices->open_devices > 1) {
			struct io_context *ioc;

			ioc = current->io_context;

			/*
			 * the main goal here is that we don't want to
			 * block if we're going to be able to submit
			 * more requests without blocking.
			 *
			 * This code does two great things, it pokes into
			 * the elevator code from a filesystem _and_
			 * it makes assumptions about how batching works.
			 */
			if (ioc && ioc->nr_batch_requests > 0 &&
			    time_before(jiffies, ioc->last_waited + HZ/50UL) &&
			    (last_waited == 0 ||
			     ioc->last_waited == last_waited)) {
				/*
				 * we want to go through our batch of
				 * requests and stop.  So, we copy out
				 * the ioc->last_waited time and test
				 * against it before looping
				 */
				last_waited = ioc->last_waited;
				cond_resched();
				continue;
			}
			spin_lock(&device->io_lock);
			requeue_list(pending_bios, pending, tail);
			device->running_pending = 1;

			spin_unlock(&device->io_lock);
			btrfs_queue_work(fs_info->submit_workers,
					 &device->work);
			goto done;
		}
	}

	cond_resched();
	if (again)
		goto loop;

	spin_lock(&device->io_lock);
	if (device->pending_bios.head || device->pending_sync_bios.head)
		goto loop_lock;
	spin_unlock(&device->io_lock);

done:
	blk_finish_plug(&plug);
}

Project: linux
File: volumes.c

int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path)
{
	struct btrfs_root *root = fs_info->dev_root;
	struct request_queue *q;
	struct btrfs_trans_handle *trans;
	struct btrfs_device *device;
	struct block_device *bdev;
	struct super_block *sb = fs_info->sb;
	struct rcu_string *name;
	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
	u64 orig_super_total_bytes;
	u64 orig_super_num_devices;
	int seeding_dev = 0;
	int ret = 0;
	bool unlocked = false;

	if (sb_rdonly(sb) && !fs_devices->seeding)
		return -EROFS;

	bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
				  fs_info->bdev_holder);
	if (IS_ERR(bdev))
		return PTR_ERR(bdev);

	if (fs_devices->seeding) {
		seeding_dev = 1;
		down_write(&sb->s_umount);
		mutex_lock(&uuid_mutex);
	}

	filemap_write_and_wait(bdev->bd_inode->i_mapping);

	mutex_lock(&fs_devices->device_list_mutex);
	list_for_each_entry(device, &fs_devices->devices, dev_list) {
		if (device->bdev == bdev) {
			ret = -EEXIST;
			mutex_unlock(
				&fs_devices->device_list_mutex);
			goto error;
		}
	}
	mutex_unlock(&fs_devices->device_list_mutex);

	device = btrfs_alloc_device(fs_info, NULL, NULL);
	if (IS_ERR(device)) {
		/* we can safely leave the fs_devices entry around */
		ret = PTR_ERR(device);
		goto error;
	}

	name = rcu_string_strdup(device_path, GFP_KERNEL);
	if (!name) {
		ret = -ENOMEM;
		goto error_free_device;
	}
	rcu_assign_pointer(device->name, name);

	trans = btrfs_start_transaction(root, 0);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		goto error_free_device;
	}

	q = bdev_get_queue(bdev);
	set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
	device->generation = trans->transid;
	device->io_width = fs_info->sectorsize;
	device->io_align = fs_info->sectorsize;
	device->sector_size = fs_info->sectorsize;
	device->total_bytes = round_down(i_size_read(bdev->bd_inode),
					 fs_info->sectorsize);
	device->disk_total_bytes = device->total_bytes;
	device->commit_total_bytes = device->total_bytes;
	device->fs_info = fs_info;
	device->bdev = bdev;
	set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
	clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
	device->mode = FMODE_EXCL;
	device->dev_stats_valid = 1;
	set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE);

	if (seeding_dev) {
		sb->s_flags &= ~SB_RDONLY;
		ret = btrfs_prepare_sprout(fs_info);
		if (ret) {
			btrfs_abort_transaction(trans, ret);
			goto error_trans;
		}
	}

	device->fs_devices = fs_devices;

	mutex_lock(&fs_devices->device_list_mutex);
	mutex_lock(&fs_info->chunk_mutex);
	list_add_rcu(&device->dev_list, &fs_devices->devices);
	list_add(&device->dev_alloc_list, &fs_devices->alloc_list);
	fs_devices->num_devices++;
	fs_devices->open_devices++;
	fs_devices->rw_devices++;
	fs_devices->total_devices++;
	fs_devices->total_rw_bytes += device->total_bytes;

	atomic64_add(device->total_bytes, &fs_info->free_chunk_space);

	if (!blk_queue_nonrot(q))
		fs_devices->rotating = 1;

	orig_super_total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
	btrfs_set_super_total_bytes(fs_info->super_copy,
		round_down(orig_super_total_bytes + device->total_bytes,
			   fs_info->sectorsize));

	orig_super_num_devices = btrfs_super_num_devices(fs_info->super_copy);
	btrfs_set_super_num_devices(fs_info->super_copy,
				    orig_super_num_devices + 1);

	/* add sysfs device entry */
	btrfs_sysfs_add_device_link(fs_devices, device);

	/*
	 * we've got more storage, clear any full flags on the space
	 * infos
	 */
	btrfs_clear_space_info_full(fs_info);

	mutex_unlock(&fs_info->chunk_mutex);
	mutex_unlock(&fs_devices->device_list_mutex);

	if (seeding_dev) {
		mutex_lock(&fs_info->chunk_mutex);
		ret = init_first_rw_device(trans, fs_info);
		mutex_unlock(&fs_info->chunk_mutex);
		if (ret) {
			btrfs_abort_transaction(trans, ret);
			goto error_sysfs;
		}
	}

	ret = btrfs_add_dev_item(trans, device);
	if (ret) {
		btrfs_abort_transaction(trans, ret);
		goto error_sysfs;
	}

	if (seeding_dev) {
		char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];

		ret = btrfs_finish_sprout(trans, fs_info);
		if (ret) {
			btrfs_abort_transaction(trans, ret);
			goto error_sysfs;
		}

		/* Sprouting would change fsid of the mounted root,
		 * so rename the fsid on the sysfs
		 */
		snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU",
						fs_info->fs_devices->fsid);
		if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
			btrfs_warn(fs_info,
				   "sysfs: failed to create fsid for sprout");
	}

	ret = btrfs_commit_transaction(trans);

	if (seeding_dev) {
		mutex_unlock(&uuid_mutex);
		up_write(&sb->s_umount);
		unlocked = true;

		if (ret) /* transaction commit */
			return ret;

		ret = btrfs_relocate_sys_chunks(fs_info);
		if (ret < 0)
			btrfs_handle_fs_error(fs_info, ret,
				    "Failed to relocate sys chunks after device initialization. This can be fixed using the \"btrfs balance\" command.");
		trans = btrfs_attach_transaction(root);
		if (IS_ERR(trans)) {
			if (PTR_ERR(trans) == -ENOENT)
				return 0;
			ret = PTR_ERR(trans);
			trans = NULL;
			goto error_sysfs;
		}
		ret = btrfs_commit_transaction(trans);
	}

	/* Update ctime/mtime for libblkid */
	update_dev_time(device_path);
	return ret;

error_sysfs:
	btrfs_sysfs_rm_device_link(fs_devices, device);
	mutex_lock(&fs_info->fs_devices->device_list_mutex);
	mutex_lock(&fs_info->chunk_mutex);
	list_del_rcu(&device->dev_list);
	list_del(&device->dev_alloc_list);
	fs_info->fs_devices->num_devices--;
	fs_info->fs_devices->open_devices--;
	fs_info->fs_devices->rw_devices--;
	fs_info->fs_devices->total_devices--;
	fs_info->fs_devices->total_rw_bytes -= device->total_bytes;
	atomic64_sub(device->total_bytes, &fs_info->free_chunk_space);
	btrfs_set_super_total_bytes(fs_info->super_copy,
				    orig_super_total_bytes);
	btrfs_set_super_num_devices(fs_info->super_copy,
				    orig_super_num_devices);
	mutex_unlock(&fs_info->chunk_mutex);
	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
error_trans:
	if (seeding_dev)
		sb->s_flags |= SB_RDONLY;
	if (trans)
		btrfs_end_transaction(trans);
error_free_device:
	btrfs_free_device(device);
error:
	blkdev_put(bdev, FMODE_EXCL);
	if (seeding_dev && !unlocked) {
		mutex_unlock(&uuid_mutex);
		up_write(&sb->s_umount);
	}
	return ret;
}

Project: linux
File: ioctl.c

static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
				const char *name, unsigned long fd, int subvol,
				u64 *transid, bool readonly,
				struct btrfs_qgroup_inherit *inherit)
{
	int namelen;
	int ret = 0;

	if (!S_ISDIR(file_inode(file)->i_mode))
		return -ENOTDIR;

	ret = mnt_want_write_file(file);
	if (ret)
		goto out;

	namelen = strlen(name);
	if (strchr(name, '/')) {
		ret = -EINVAL;
		goto out_drop_write;
	}

	if (name[0] == '.' &&
	   (namelen == 1 || (name[1] == '.' && namelen == 2))) {
		ret = -EEXIST;
		goto out_drop_write;
	}

	if (subvol) {
		ret = btrfs_mksubvol(&file->f_path, name, namelen,
				     NULL, transid, readonly, inherit);
	} else {
		struct fd src = fdget(fd);
		struct inode *src_inode;
		if (!src.file) {
			ret = -EINVAL;
			goto out_drop_write;
		}

		src_inode = file_inode(src.file);
		if (src_inode->i_sb != file_inode(file)->i_sb) {
			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
				   "Snapshot src from another FS");
			ret = -EXDEV;
		} else if (!inode_owner_or_capable(src_inode)) {
			/*
			 * Subvolume creation is not restricted, but snapshots
			 * are limited to own subvolumes only
			 */
			ret = -EPERM;
		} else {
			ret = btrfs_mksubvol(&file->f_path, name, namelen,
					     BTRFS_I(src_inode)->root,
					     transid, readonly, inherit);
		}
		fdput(src);
	}
out_drop_write:
	mnt_drop_write_file(file);
out:
	return ret;
}

Project: linux
File: volumes.c

struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
					   void *holder)
{
	struct btrfs_super_block *disk_super;
	bool new_device_added = false;
	struct btrfs_device *device = NULL;
	struct block_device *bdev;
	struct page *page;
	u64 bytenr;

	lockdep_assert_held(&uuid_mutex);

	/*
	 * we would like to check all the supers, but that would make
	 * a btrfs mount succeed after a mkfs from a different FS.
	 * So, we need to add a special mount option to scan for
	 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
	 */
	bytenr = btrfs_sb_offset(0);
	flags |= FMODE_EXCL;

	bdev = blkdev_get_by_path(path, flags, holder);
	if (IS_ERR(bdev))
		return ERR_CAST(bdev);

	if (btrfs_read_disk_super(bdev, bytenr, &page, &disk_super)) {
		device = ERR_PTR(-EINVAL);
		goto error_bdev_put;
	}

	device = device_list_add(path, disk_super, &new_device_added);
	if (!IS_ERR(device)) {
		if (new_device_added)
			btrfs_free_stale_devices(path, device);
	}

	btrfs_release_disk_super(page);

error_bdev_put:
	blkdev_put(bdev, flags);

	return device;
}

Project: linux
File: volumes.c

void btrfs_scratch_superblocks(struct block_device *bdev, const char *device_path)
{
	struct buffer_head *bh;
	struct btrfs_super_block *disk_super;
	int copy_num;

	if (!bdev)
		return;

	for (copy_num = 0; copy_num < BTRFS_SUPER_MIRROR_MAX;
		copy_num++) {

		if (btrfs_read_dev_one_super(bdev, copy_num, &bh))
			continue;

		disk_super = (struct btrfs_super_block *)bh->b_data;

		memset(&disk_super->magic, 0, sizeof(disk_super->magic));
		set_buffer_dirty(bh);
		sync_dirty_buffer(bh);
		brelse(bh);
	}

	/* Notify udev that device has changed */
	btrfs_kobject_uevent(bdev, KOBJ_CHANGE);

	/* Update ctime/mtime for device path for libblkid */
	update_dev_time(device_path);
}

Project: linux
File: scrub.c

static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
{
	if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
		return 2;
	else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
		return 3;
	else
		return (int)bbio->num_stripes;
}

Project: linux
File: scrub.c

static void scrub_bio_end_io(struct bio *bio)
{
	struct scrub_bio *sbio = bio->bi_private;
	struct btrfs_fs_info *fs_info = sbio->dev->fs_info;

	sbio->status = bio->bi_status;
	sbio->bio = bio;

	btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
}

Project: linux
File: ioctl.c

static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
{
	struct inode *inode = file_inode(file);
	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
	struct btrfs_inode *binode = BTRFS_I(inode);
	struct btrfs_root *root = binode->root;
	struct btrfs_trans_handle *trans;
	unsigned int fsflags, old_fsflags;
	int ret;
	u64 old_flags;
	unsigned int old_i_flags;
	umode_t mode;

	if (!inode_owner_or_capable(inode))
		return -EPERM;

	if (btrfs_root_readonly(root))
		return -EROFS;

	if (copy_from_user(&fsflags, arg, sizeof(fsflags)))
		return -EFAULT;

	ret = check_fsflags(fsflags);
	if (ret)
		return ret;

	ret = mnt_want_write_file(file);
	if (ret)
		return ret;

	inode_lock(inode);

	old_flags = binode->flags;
	old_i_flags = inode->i_flags;
	mode = inode->i_mode;

	fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
	old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
	if ((fsflags ^ old_fsflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
		if (!capable(CAP_LINUX_IMMUTABLE)) {
			ret = -EPERM;
			goto out_unlock;
		}
	}

	if (fsflags & FS_SYNC_FL)
		binode->flags |= BTRFS_INODE_SYNC;
	else
		binode->flags &= ~BTRFS_INODE_SYNC;
	if (fsflags & FS_IMMUTABLE_FL)
		binode->flags |= BTRFS_INODE_IMMUTABLE;
	else
		binode->flags &= ~BTRFS_INODE_IMMUTABLE;
	if (fsflags & FS_APPEND_FL)
		binode->flags |= BTRFS_INODE_APPEND;
	else
		binode->flags &= ~BTRFS_INODE_APPEND;
	if (fsflags & FS_NODUMP_FL)
		binode->flags |= BTRFS_INODE_NODUMP;
	else
		binode->flags &= ~BTRFS_INODE_NODUMP;
	if (fsflags & FS_NOATIME_FL)
		binode->flags |= BTRFS_INODE_NOATIME;
	else
		binode->flags &= ~BTRFS_INODE_NOATIME;
	if (fsflags & FS_DIRSYNC_FL)
		binode->flags |= BTRFS_INODE_DIRSYNC;
	else
		binode->flags &= ~BTRFS_INODE_DIRSYNC;
	if (fsflags & FS_NOCOW_FL) {
		if (S_ISREG(mode)) {
			/*
			 * It's safe to turn csums off here, no extents exist.
			 * Otherwise we want the flag to reflect the real COW
			 * status of the file and will not set it.
			 */
			if (inode->i_size == 0)
				binode->flags |= BTRFS_INODE_NODATACOW
					      | BTRFS_INODE_NODATASUM;
		} else {
			binode->flags |= BTRFS_INODE_NODATACOW;
		}
	} else {
		/*
		 * Revert back under same assumptions as above
		 */
		if (S_ISREG(mode)) {
			if (inode->i_size == 0)
				binode->flags &= ~(BTRFS_INODE_NODATACOW
				             | BTRFS_INODE_NODATASUM);
		} else {
			binode->flags &= ~BTRFS_INODE_NODATACOW;
		}
	}

	/*
	 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
	 * flag may be changed automatically if compression code won't make
	 * things smaller.
	 */
	if (fsflags & FS_NOCOMP_FL) {
		binode->flags &= ~BTRFS_INODE_COMPRESS;
		binode->flags |= BTRFS_INODE_NOCOMPRESS;

		ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
		if (ret && ret != -ENODATA)
			goto out_drop;
	} else if (fsflags & FS_COMPR_FL) {
		const char *comp;

		if (IS_SWAPFILE(inode)) {
			ret = -ETXTBSY;
			goto out_unlock;
		}

		binode->flags |= BTRFS_INODE_COMPRESS;
		binode->flags &= ~BTRFS_INODE_NOCOMPRESS;

		comp = btrfs_compress_type2str(fs_info->compress_type);
		if (!comp || comp[0] == 0)
			comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);

		ret = btrfs_set_prop(inode, "btrfs.compression",
				     comp, strlen(comp), 0);
		if (ret)
			goto out_drop;

	} else {
		ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
		if (ret && ret != -ENODATA)
			goto out_drop;
		binode->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
	}

	trans = btrfs_start_transaction(root, 1);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		goto out_drop;
	}

	btrfs_sync_inode_flags_to_i_flags(inode);
	inode_inc_iversion(inode);
	inode->i_ctime = current_time(inode);
	ret = btrfs_update_inode(trans, root, inode);

	btrfs_end_transaction(trans);
 out_drop:
	if (ret) {
		binode->flags = old_flags;
		inode->i_flags = old_i_flags;
	}

 out_unlock:
	inode_unlock(inode);
	mnt_drop_write_file(file);
	return ret;
}

Project: linux
File: dev-replace.c

void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount)
{
	percpu_counter_sub(&fs_info->dev_replace.bio_counter, amount);
	cond_wake_up_nomb(&fs_info->dev_replace.replace_wait);
}

Project: linux
File: ioctl.c

static noinline int btrfs_ioctl_snap_create(struct file *file,
					    void __user *arg, int subvol)
{
	struct btrfs_ioctl_vol_args *vol_args;
	int ret;

	if (!S_ISDIR(file_inode(file)->i_mode))
		return -ENOTDIR;

	vol_args = memdup_user(arg, sizeof(*vol_args));
	if (IS_ERR(vol_args))
		return PTR_ERR(vol_args);
	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';

	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
					      vol_args->fd, subvol,
					      NULL, false, NULL);

	kfree(vol_args);
	return ret;
}

Project: linux
File: volumes.c

static struct btrfs_fs_devices *find_fsid_inprogress(
					struct btrfs_super_block *disk_super)
{
	struct btrfs_fs_devices *fs_devices;

	list_for_each_entry(fs_devices, &fs_uuids, fs_list) {
		if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid,
			   BTRFS_FSID_SIZE) != 0 &&
		    memcmp(fs_devices->metadata_uuid, disk_super->fsid,
			   BTRFS_FSID_SIZE) == 0 && !fs_devices->fsid_change) {
			return fs_devices;
		}
	}

	return NULL;
}

Project: linux
File: ioctl.c

static void btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
				     struct inode *inode2, u64 loff2, u64 len)
{
	if (inode1 < inode2) {
		swap(inode1, inode2);
		swap(loff1, loff2);
	} else if (inode1 == inode2 && loff2 < loff1) {
		swap(loff1, loff2);
	}
	lock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
	lock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
}

Project: linux
File: ioctl.c

static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
					 void __user *arg)
{
	struct btrfs_ioctl_balance_args *bargs;
	int ret = 0;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	mutex_lock(&fs_info->balance_mutex);
	if (!fs_info->balance_ctl) {
		ret = -ENOTCONN;
		goto out;
	}

	bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
	if (!bargs) {
		ret = -ENOMEM;
		goto out;
	}

	btrfs_update_ioctl_balance_args(fs_info, bargs);

	if (copy_to_user(arg, bargs, sizeof(*bargs)))
		ret = -EFAULT;

	kfree(bargs);
out:
	mutex_unlock(&fs_info->balance_mutex);
	return ret;
}

Project: linux
File: ioctl.c

static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
				     struct inode *inode,
				     u64 endoff,
				     const u64 destoff,
				     const u64 olen,
				     int no_time_update)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	int ret;

	inode_inc_iversion(inode);
	if (!no_time_update)
		inode->i_mtime = inode->i_ctime = current_time(inode);
	/*
	 * We round up to the block size at eof when determining which
	 * extents to clone above, but shouldn't round up the file size.
	 */
	if (endoff > destoff + olen)
		endoff = destoff + olen;
	if (endoff > inode->i_size)
		btrfs_i_size_write(BTRFS_I(inode), endoff);

	ret = btrfs_update_inode(trans, root, inode);
	if (ret) {
		btrfs_abort_transaction(trans, ret);
		btrfs_end_transaction(trans);
		goto out;
	}
	ret = btrfs_end_transaction(trans);
out:
	return ret;
}

Project: linux
File: volumes.c

static int find_live_mirror(struct btrfs_fs_info *fs_info,
			    struct map_lookup *map, int first,
			    int dev_replace_is_ongoing)
{
	int i;
	int num_stripes;
	int preferred_mirror;
	int tolerance;
	struct btrfs_device *srcdev;

	ASSERT((map->type &
		 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)));

	if (map->type & BTRFS_BLOCK_GROUP_RAID10)
		num_stripes = map->sub_stripes;
	else
		num_stripes = map->num_stripes;

	preferred_mirror = first + current->pid % num_stripes;

	if (dev_replace_is_ongoing &&
	    fs_info->dev_replace.cont_reading_from_srcdev_mode ==
	     BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
		srcdev = fs_info->dev_replace.srcdev;
	else
		srcdev = NULL;

	/*
	 * try to avoid the drive that is the source drive for a
	 * dev-replace procedure, only choose it if no other non-missing
	 * mirror is available
	 */
	for (tolerance = 0; tolerance < 2; tolerance++) {
		if (map->stripes[preferred_mirror].dev->bdev &&
		    (tolerance || map->stripes[preferred_mirror].dev != srcdev))
			return preferred_mirror;
		for (i = first; i < first + num_stripes; i++) {
			if (map->stripes[i].dev->bdev &&
			    (tolerance || map->stripes[i].dev != srcdev))
				return i;
		}
	}

	/* we couldn't find one that doesn't fail.  Just return something
	 * and the io error handling code will clean up eventually
	 */
	return preferred_mirror;
}

Project: linux
File: ioctl.c

long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	/*
	 * These all access 32-bit values anyway so no further
	 * handling is necessary.
	 */
	switch (cmd) {
	case FS_IOC32_GETFLAGS:
		cmd = FS_IOC_GETFLAGS;
		break;
	case FS_IOC32_SETFLAGS:
		cmd = FS_IOC_SETFLAGS;
		break;
	case FS_IOC32_GETVERSION:
		cmd = FS_IOC_GETVERSION;
		break;
	}

	return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
}

Project: linux
File: ioctl.c

static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
					       void __user *arg, int subvol)
{
	struct btrfs_ioctl_vol_args_v2 *vol_args;
	int ret;
	u64 transid = 0;
	u64 *ptr = NULL;
	bool readonly = false;
	struct btrfs_qgroup_inherit *inherit = NULL;

	if (!S_ISDIR(file_inode(file)->i_mode))
		return -ENOTDIR;

	vol_args = memdup_user(arg, sizeof(*vol_args));
	if (IS_ERR(vol_args))
		return PTR_ERR(vol_args);
	vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';

	if (vol_args->flags &
	    ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
	      BTRFS_SUBVOL_QGROUP_INHERIT)) {
		ret = -EOPNOTSUPP;
		goto free_args;
	}

	if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
		ptr = &transid;
	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
		readonly = true;
	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
		if (vol_args->size > PAGE_SIZE) {
			ret = -EINVAL;
			goto free_args;
		}
		inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
		if (IS_ERR(inherit)) {
			ret = PTR_ERR(inherit);
			goto free_args;
		}
	}

	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
					      vol_args->fd, subvol, ptr,
					      readonly, inherit);
	if (ret)
		goto free_inherit;

	if (ptr && copy_to_user(arg +
				offsetof(struct btrfs_ioctl_vol_args_v2,
					transid),
				ptr, sizeof(*ptr)))
		ret = -EFAULT;

free_inherit:
	kfree(inherit);
free_args:
	kfree(vol_args);
	return ret;
}

Project: linux
File: ioctl.c

static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
					void __user *arg, int version)
{
	int ret = 0;
	int size;
	struct btrfs_ioctl_logical_ino_args *loi;
	struct btrfs_data_container *inodes = NULL;
	struct btrfs_path *path = NULL;
	bool ignore_offset;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	loi = memdup_user(arg, sizeof(*loi));
	if (IS_ERR(loi))
		return PTR_ERR(loi);

	if (version == 1) {
		ignore_offset = false;
		size = min_t(u32, loi->size, SZ_64K);
	} else {
		/* All reserved bits must be 0 for now */
		if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
			ret = -EINVAL;
			goto out_loi;
		}
		/* Only accept flags we have defined so far */
		if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
			ret = -EINVAL;
			goto out_loi;
		}
		ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
		size = min_t(u32, loi->size, SZ_16M);
	}

	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}

	inodes = init_data_container(size);
	if (IS_ERR(inodes)) {
		ret = PTR_ERR(inodes);
		inodes = NULL;
		goto out;
	}

	ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
					  build_ino_list, inodes, ignore_offset);
	if (ret == -EINVAL)
		ret = -ENOENT;
	if (ret < 0)
		goto out;

	ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
			   size);
	if (ret)
		ret = -EFAULT;

out:
	btrfs_free_path(path);
	kvfree(inodes);
out_loi:
	kfree(loi);

	return ret;
}

Project: linux
File: volumes.c

static int alloc_profile_is_valid(u64 flags, int extended)
{
	u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
			       BTRFS_BLOCK_GROUP_PROFILE_MASK);

	flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;

	/* 1) check that all other bits are zeroed */
	if (flags & ~mask)
		return 0;

	/* 2) see if profile is reduced */
	if (flags == 0)
		return !extended; /* "0" is valid for usual profiles */

	/* true if exactly one bit set */
	return is_power_of_2(flags);
}

Project: linux
File: volumes.c

static int chunk_drange_filter(struct extent_buffer *leaf,
			       struct btrfs_chunk *chunk,
			       struct btrfs_balance_args *bargs)
{
	struct btrfs_stripe *stripe;
	int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
	u64 stripe_offset;
	u64 stripe_length;
	int factor;
	int i;

	if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
		return 0;

	if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
	     BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
		factor = num_stripes / 2;
	} else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
		factor = num_stripes - 1;
	} else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
		factor = num_stripes - 2;
	} else {
		factor = num_stripes;
	}

	for (i = 0; i < num_stripes; i++) {
		stripe = btrfs_stripe_nr(chunk, i);
		if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
			continue;

		stripe_offset = btrfs_stripe_offset(leaf, stripe);
		stripe_length = btrfs_chunk_length(leaf, chunk);
		stripe_length = div_u64(stripe_length, factor);

		if (stripe_offset < bargs->pend &&
		    stripe_offset + stripe_length > bargs->pstart)
			return 0;
	}

	return 1;
}

Project: linux
File: volumes.c

static noinline int find_next_devid(struct btrfs_fs_info *fs_info,
				    u64 *devid_ret)
{
	int ret;
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct btrfs_path *path;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
	key.type = BTRFS_DEV_ITEM_KEY;
	key.offset = (u64)-1;

	ret = btrfs_search_slot(NULL, fs_info->chunk_root, &key, path, 0, 0);
	if (ret < 0)
		goto error;

	BUG_ON(ret == 0); /* Corruption */

	ret = btrfs_previous_item(fs_info->chunk_root, path,
				  BTRFS_DEV_ITEMS_OBJECTID,
				  BTRFS_DEV_ITEM_KEY);
	if (ret) {
		*devid_ret = 1;
	} else {
		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
				      path->slots[0]);
		*devid_ret = found_key.offset + 1;
	}
	ret = 0;
error:
	btrfs_free_path(path);
	return ret;
}

Project: linux
File: volumes.c

static int verify_one_dev_extent(struct btrfs_fs_info *fs_info,
				 u64 chunk_offset, u64 devid,
				 u64 physical_offset, u64 physical_len)
{
	struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
	struct extent_map *em;
	struct map_lookup *map;
	struct btrfs_device *dev;
	u64 stripe_len;
	bool found = false;
	int ret = 0;
	int i;

	read_lock(&em_tree->lock);
	em = lookup_extent_mapping(em_tree, chunk_offset, 1);
	read_unlock(&em_tree->lock);

	if (!em) {
		btrfs_err(fs_info,
"dev extent physical offset %llu on devid %llu doesn't have corresponding chunk",
			  physical_offset, devid);
		ret = -EUCLEAN;
		goto out;
	}

	map = em->map_lookup;
	stripe_len = calc_stripe_length(map->type, em->len, map->num_stripes);
	if (physical_len != stripe_len) {
		btrfs_err(fs_info,
"dev extent physical offset %llu on devid %llu length doesn't match chunk %llu, have %llu expect %llu",
			  physical_offset, devid, em->start, physical_len,
			  stripe_len);
		ret = -EUCLEAN;
		goto out;
	}

	for (i = 0; i < map->num_stripes; i++) {
		if (map->stripes[i].dev->devid == devid &&
		    map->stripes[i].physical == physical_offset) {
			found = true;
			if (map->verified_stripes >= map->num_stripes) {
				btrfs_err(fs_info,
				"too many dev extents for chunk %llu found",
					  em->start);
				ret = -EUCLEAN;
				goto out;
			}
			map->verified_stripes++;
			break;
		}
	}
	if (!found) {
		btrfs_err(fs_info,
	"dev extent physical offset %llu devid %llu has no corresponding chunk",
			physical_offset, devid);
		ret = -EUCLEAN;
	}

	/* Make sure no dev extent is beyond device bondary */
	dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
	if (!dev) {
		btrfs_err(fs_info, "failed to find devid %llu", devid);
		ret = -EUCLEAN;
		goto out;
	}

	/* It's possible this device is a dummy for seed device */
	if (dev->disk_total_bytes == 0) {
		dev = btrfs_find_device(fs_info->fs_devices->seed, devid, NULL,
					NULL, false);
		if (!dev) {
			btrfs_err(fs_info, "failed to find seed devid %llu",
				  devid);
			ret = -EUCLEAN;
			goto out;
		}
	}

	if (physical_offset + physical_len > dev->disk_total_bytes) {
		btrfs_err(fs_info,
"dev extent devid %llu physical offset %llu len %llu is beyond device boundary %llu",
			  devid, physical_offset, physical_len,
			  dev->disk_total_bytes);
		ret = -EUCLEAN;
		goto out;
	}
out:
	free_extent_map(em);
	return ret;
}

Project: linux
File: scrub.c

static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
{
	while (atomic_read(&fs_info->scrub_pause_req)) {
		mutex_unlock(&fs_info->scrub_lock);
		wait_event(fs_info->scrub_pause_wait,
		   atomic_read(&fs_info->scrub_pause_req) == 0);
		mutex_lock(&fs_info->scrub_lock);
	}
}

Project: linux
File: scrub.c

static void scrub_recheck_block_on_raid56(struct btrfs_fs_info *fs_info,
					  struct scrub_block *sblock)
{
	struct scrub_page *first_page = sblock->pagev[0];
	struct bio *bio;
	int page_num;

	/* All pages in sblock belong to the same stripe on the same device. */
	ASSERT(first_page->dev);
	if (!first_page->dev->bdev)
		goto out;

	bio = btrfs_io_bio_alloc(BIO_MAX_PAGES);
	bio_set_dev(bio, first_page->dev->bdev);

	for (page_num = 0; page_num < sblock->page_count; page_num++) {
		struct scrub_page *page = sblock->pagev[page_num];

		WARN_ON(!page->page);
		bio_add_page(bio, page->page, PAGE_SIZE, 0);
	}

	if (scrub_submit_raid56_bio_wait(fs_info, bio, first_page)) {
		bio_put(bio);
		goto out;
	}

	bio_put(bio);

	scrub_recheck_block_checksum(sblock);

	return;
out:
	for (page_num = 0; page_num < sblock->page_count; page_num++)
		sblock->pagev[page_num]->io_error = 1;

	sblock->no_io_error_seen = 0;
}

Project: linux
File: scrub.c

static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map,
			u64 logical, u64 len,
			u64 physical, struct btrfs_device *dev, u64 flags,
			u64 gen, int mirror_num, u64 physical_for_dev_replace)
{
	int ret;
	u8 csum[BTRFS_CSUM_SIZE];
	u32 blocksize;

	if (flags & BTRFS_EXTENT_FLAG_DATA) {
		if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
			blocksize = map->stripe_len;
		else
			blocksize = sctx->fs_info->sectorsize;
		spin_lock(&sctx->stat_lock);
		sctx->stat.data_extents_scrubbed++;
		sctx->stat.data_bytes_scrubbed += len;
		spin_unlock(&sctx->stat_lock);
	} else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
		if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
			blocksize = map->stripe_len;
		else
			blocksize = sctx->fs_info->nodesize;
		spin_lock(&sctx->stat_lock);
		sctx->stat.tree_extents_scrubbed++;
		sctx->stat.tree_bytes_scrubbed += len;
		spin_unlock(&sctx->stat_lock);
	} else {
		blocksize = sctx->fs_info->sectorsize;
		WARN_ON(1);
	}

	while (len) {
		u64 l = min_t(u64, len, blocksize);
		int have_csum = 0;

		if (flags & BTRFS_EXTENT_FLAG_DATA) {
			/* push csums to sbio */
			have_csum = scrub_find_csum(sctx, logical, csum);
			if (have_csum == 0)
				++sctx->stat.no_csum;
		}
		ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
				  mirror_num, have_csum ? csum : NULL, 0,
				  physical_for_dev_replace);
		if (ret)
			return ret;
		len -= l;
		logical += l;
		physical += l;
		physical_for_dev_replace += l;
	}
	return 0;
}

Project: linux
File: scrub.c

void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
{
	mutex_lock(&fs_info->scrub_lock);
	atomic_inc(&fs_info->scrub_pause_req);
	while (atomic_read(&fs_info->scrubs_paused) !=
	       atomic_read(&fs_info->scrubs_running)) {
		mutex_unlock(&fs_info->scrub_lock);
		wait_event(fs_info->scrub_pause_wait,
			   atomic_read(&fs_info->scrubs_paused) ==
			   atomic_read(&fs_info->scrubs_running));
		mutex_lock(&fs_info->scrub_lock);
	}
	mutex_unlock(&fs_info->scrub_lock);
}

Project: linux
File: ioctl.c

int btrfs_ioctl_get_supported_features(void __user *arg)
{
	static const struct btrfs_ioctl_feature_flags features[3] = {
		INIT_FEATURE_FLAGS(SUPP),
		INIT_FEATURE_FLAGS(SAFE_SET),
		INIT_FEATURE_FLAGS(SAFE_CLEAR)
	};

	if (copy_to_user(arg, &features, sizeof(features)))
		return -EFAULT;

	return 0;
}

Project: linux
File: ioctl.c

static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
					u64 off, u64 olen, u64 destoff)
{
	struct inode *inode = file_inode(file);
	struct inode *src = file_inode(file_src);
	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
	int ret;
	u64 len = olen;
	u64 bs = fs_info->sb->s_blocksize;

	/*
	 * TODO:
	 * - split compressed inline extents.  annoying: we need to
	 *   decompress into destination's address_space (the file offset
	 *   may change, so source mapping won't do), then recompress (or
	 *   otherwise reinsert) a subrange.
	 *
	 * - split destination inode's inline extents.  The inline extents can
	 *   be either compressed or non-compressed.
	 */

	/*
	 * VFS's generic_remap_file_range_prep() protects us from cloning the
	 * eof block into the middle of a file, which would result in corruption
	 * if the file size is not blocksize aligned. So we don't need to check
	 * for that case here.
	 */
	if (off + len == src->i_size)
		len = ALIGN(src->i_size, bs) - off;

	if (destoff > inode->i_size) {
		const u64 wb_start = ALIGN_DOWN(inode->i_size, bs);

		ret = btrfs_cont_expand(inode, inode->i_size, destoff);
		if (ret)
			return ret;
		/*
		 * We may have truncated the last block if the inode's size is
		 * not sector size aligned, so we need to wait for writeback to
		 * complete before proceeding further, otherwise we can race
		 * with cloning and attempt to increment a reference to an
		 * extent that no longer exists (writeback completed right after
		 * we found the previous extent covering eof and before we
		 * attempted to increment its reference count).
		 */
		ret = btrfs_wait_ordered_range(inode, wb_start,
					       destoff - wb_start);
		if (ret)
			return ret;
	}

	/*
	 * Lock destination range to serialize with concurrent readpages() and
	 * source range to serialize with relocation.
	 */
	btrfs_double_extent_lock(src, off, inode, destoff, len);
	ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
	btrfs_double_extent_unlock(src, off, inode, destoff, len);
	/*
	 * Truncate page cache pages so that future reads will see the cloned
	 * data immediately and not the previous data.
	 */
	truncate_inode_pages_range(&inode->i_data,
				round_down(destoff, PAGE_SIZE),
				round_up(destoff + len, PAGE_SIZE) - 1);

	return ret;
}

Project: linux
File: ioctl.c

static long btrfs_ioctl_set_received_subvol(struct file *file,
					    void __user *arg)
{
	struct btrfs_ioctl_received_subvol_args *sa = NULL;
	int ret = 0;

	sa = memdup_user(arg, sizeof(*sa));
	if (IS_ERR(sa))
		return PTR_ERR(sa);

	ret = _btrfs_ioctl_set_received_subvol(file, sa);

	if (ret)
		goto out;

	ret = copy_to_user(arg, sa, sizeof(*sa));
	if (ret)
		ret = -EFAULT;

out:
	kfree(sa);
	return ret;
}

Project: linux
File: scrub.c

static int scrub_checksum_super(struct scrub_block *sblock)
{
	struct btrfs_super_block *s;
	struct scrub_ctx *sctx = sblock->sctx;
	u8 calculated_csum[BTRFS_CSUM_SIZE];
	u8 on_disk_csum[BTRFS_CSUM_SIZE];
	struct page *page;
	void *mapped_buffer;
	u64 mapped_size;
	void *p;
	u32 crc = ~(u32)0;
	int fail_gen = 0;
	int fail_cor = 0;
	u64 len;
	int index;

	BUG_ON(sblock->page_count < 1);
	page = sblock->pagev[0]->page;
	mapped_buffer = kmap_atomic(page);
	s = (struct btrfs_super_block *)mapped_buffer;
	memcpy(on_disk_csum, s->csum, sctx->csum_size);

	if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
		++fail_cor;

	if (sblock->pagev[0]->generation != btrfs_super_generation(s))
		++fail_gen;

	if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
		++fail_cor;

	len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
	mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
	p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
	index = 0;
	for (;;) {
		u64 l = min_t(u64, len, mapped_size);

		crc = btrfs_csum_data(p, crc, l);
		kunmap_atomic(mapped_buffer);
		len -= l;
		if (len == 0)
			break;
		index++;
		BUG_ON(index >= sblock->page_count);
		BUG_ON(!sblock->pagev[index]->page);
		page = sblock->pagev[index]->page;
		mapped_buffer = kmap_atomic(page);
		mapped_size = PAGE_SIZE;
		p = mapped_buffer;
	}

	btrfs_csum_final(crc, calculated_csum);
	if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
		++fail_cor;

	if (fail_cor + fail_gen) {
		/*
		 * if we find an error in a super block, we just report it.
		 * They will get written with the next transaction commit
		 * anyway
		 */
		spin_lock(&sctx->stat_lock);
		++sctx->stat.super_errors;
		spin_unlock(&sctx->stat_lock);
		if (fail_cor)
			btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
				BTRFS_DEV_STAT_CORRUPTION_ERRS);
		else
			btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
				BTRFS_DEV_STAT_GENERATION_ERRS);
	}

	return fail_cor + fail_gen;
}

Project: linux
File: scrub.c

static int scrub_pages_for_parity(struct scrub_parity *sparity,
				  u64 logical, u64 len,
				  u64 physical, struct btrfs_device *dev,
				  u64 flags, u64 gen, int mirror_num, u8 *csum)
{
	struct scrub_ctx *sctx = sparity->sctx;
	struct scrub_block *sblock;
	int index;

	sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
	if (!sblock) {
		spin_lock(&sctx->stat_lock);
		sctx->stat.malloc_errors++;
		spin_unlock(&sctx->stat_lock);
		return -ENOMEM;
	}

	/* one ref inside this function, plus one for each page added to
	 * a bio later on */
	refcount_set(&sblock->refs, 1);
	sblock->sctx = sctx;
	sblock->no_io_error_seen = 1;
	sblock->sparity = sparity;
	scrub_parity_get(sparity);

	for (index = 0; len > 0; index++) {
		struct scrub_page *spage;
		u64 l = min_t(u64, len, PAGE_SIZE);

		spage = kzalloc(sizeof(*spage), GFP_KERNEL);
		if (!spage) {
leave_nomem:
			spin_lock(&sctx->stat_lock);
			sctx->stat.malloc_errors++;
			spin_unlock(&sctx->stat_lock);
			scrub_block_put(sblock);
			return -ENOMEM;
		}
		BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
		/* For scrub block */
		scrub_page_get(spage);
		sblock->pagev[index] = spage;
		/* For scrub parity */
		scrub_page_get(spage);
		list_add_tail(&spage->list, &sparity->spages);
		spage->sblock = sblock;
		spage->dev = dev;
		spage->flags = flags;
		spage->generation = gen;
		spage->logical = logical;
		spage->physical = physical;
		spage->mirror_num = mirror_num;
		if (csum) {
			spage->have_csum = 1;
			memcpy(spage->csum, csum, sctx->csum_size);
		} else {
			spage->have_csum = 0;
		}
		sblock->page_count++;
		spage->page = alloc_page(GFP_KERNEL);
		if (!spage->page)
			goto leave_nomem;
		len -= l;
		logical += l;
		physical += l;
	}

	WARN_ON(sblock->page_count == 0);
	for (index = 0; index < sblock->page_count; index++) {
		struct scrub_page *spage = sblock->pagev[index];
		int ret;

		ret = scrub_add_page_to_rd_bio(sctx, spage);
		if (ret) {
			scrub_block_put(sblock);
			return ret;
		}
	}

	/* last one frees, either here or in bio completion for last page */
	scrub_block_put(sblock);
	return 0;
}

Project: linux
File: scrub.c

static void scrub_page_get(struct scrub_page *spage)
{
	atomic_inc(&spage->refs);
}

Project: linux
File: dev-replace.c

static char* btrfs_dev_name(struct btrfs_device *device)
{
	if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))
		return "<missing disk>";
	else
		return rcu_str_deref(device->name);
}

Project: linux
File: volumes.c

static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
			     enum btrfs_map_op op,
			     u64 logical, u64 *length,
			     struct btrfs_bio **bbio_ret,
			     int mirror_num, int need_raid_map)
{
	struct extent_map *em;
	struct map_lookup *map;
	u64 offset;
	u64 stripe_offset;
	u64 stripe_nr;
	u64 stripe_len;
	u32 stripe_index;
	int i;
	int ret = 0;
	int num_stripes;
	int max_errors = 0;
	int tgtdev_indexes = 0;
	struct btrfs_bio *bbio = NULL;
	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
	int dev_replace_is_ongoing = 0;
	int num_alloc_stripes;
	int patch_the_first_stripe_for_dev_replace = 0;
	u64 physical_to_patch_in_first_stripe = 0;
	u64 raid56_full_stripe_start = (u64)-1;

	if (op == BTRFS_MAP_DISCARD)
		return __btrfs_map_block_for_discard(fs_info, logical,
						     *length, bbio_ret);

	em = btrfs_get_chunk_map(fs_info, logical, *length);
	if (IS_ERR(em))
		return PTR_ERR(em);

	map = em->map_lookup;
	offset = logical - em->start;

	stripe_len = map->stripe_len;
	stripe_nr = offset;
	/*
	 * stripe_nr counts the total number of stripes we have to stride
	 * to get to this block
	 */
	stripe_nr = div64_u64(stripe_nr, stripe_len);

	stripe_offset = stripe_nr * stripe_len;
	if (offset < stripe_offset) {
		btrfs_crit(fs_info,
			   "stripe math has gone wrong, stripe_offset=%llu, offset=%llu, start=%llu, logical=%llu, stripe_len=%llu",
			   stripe_offset, offset, em->start, logical,
			   stripe_len);
		free_extent_map(em);
		return -EINVAL;
	}

	/* stripe_offset is the offset of this block in its stripe*/
	stripe_offset = offset - stripe_offset;

	/* if we're here for raid56, we need to know the stripe aligned start */
	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
		unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
		raid56_full_stripe_start = offset;

		/* allow a write of a full stripe, but make sure we don't
		 * allow straddling of stripes
		 */
		raid56_full_stripe_start = div64_u64(raid56_full_stripe_start,
				full_stripe_len);
		raid56_full_stripe_start *= full_stripe_len;
	}

	if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
		u64 max_len;
		/* For writes to RAID[56], allow a full stripeset across all disks.
		   For other RAID types and for RAID[56] reads, just allow a single
		   stripe (on a single disk). */
		if ((map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) &&
		    (op == BTRFS_MAP_WRITE)) {
			max_len = stripe_len * nr_data_stripes(map) -
				(offset - raid56_full_stripe_start);
		} else {
			/* we limit the length of each bio to what fits in a stripe */
			max_len = stripe_len - stripe_offset;
		}
		*length = min_t(u64, em->len - offset, max_len);
	} else {
		*length = em->len - offset;
	}

	/*
	 * This is for when we're called from btrfs_bio_fits_in_stripe and all
	 * it cares about is the length
	 */
	if (!bbio_ret)
		goto out;

	down_read(&dev_replace->rwsem);
	dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
	/*
	 * Hold the semaphore for read during the whole operation, write is
	 * requested at commit time but must wait.
	 */
	if (!dev_replace_is_ongoing)
		up_read(&dev_replace->rwsem);

	if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
	    !need_full_stripe(op) && dev_replace->tgtdev != NULL) {
		ret = get_extra_mirror_from_replace(fs_info, logical, *length,
						    dev_replace->srcdev->devid,
						    &mirror_num,
					    &physical_to_patch_in_first_stripe);
		if (ret)
			goto out;
		else
			patch_the_first_stripe_for_dev_replace = 1;
	} else if (mirror_num > map->num_stripes) {
		mirror_num = 0;
	}

	num_stripes = 1;
	stripe_index = 0;
	if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
		stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
				&stripe_index);
		if (!need_full_stripe(op))
			mirror_num = 1;
	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
		if (need_full_stripe(op))
			num_stripes = map->num_stripes;
		else if (mirror_num)
			stripe_index = mirror_num - 1;
		else {
			stripe_index = find_live_mirror(fs_info, map, 0,
					    dev_replace_is_ongoing);
			mirror_num = stripe_index + 1;
		}

	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
		if (need_full_stripe(op)) {
			num_stripes = map->num_stripes;
		} else if (mirror_num) {
			stripe_index = mirror_num - 1;
		} else {
			mirror_num = 1;
		}

	} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
		u32 factor = map->num_stripes / map->sub_stripes;

		stripe_nr = div_u64_rem(stripe_nr, factor, &stripe_index);
		stripe_index *= map->sub_stripes;

		if (need_full_stripe(op))
			num_stripes = map->sub_stripes;
		else if (mirror_num)
			stripe_index += mirror_num - 1;
		else {
			int old_stripe_index = stripe_index;
			stripe_index = find_live_mirror(fs_info, map,
					      stripe_index,
					      dev_replace_is_ongoing);
			mirror_num = stripe_index - old_stripe_index + 1;
		}

	} else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
		if (need_raid_map && (need_full_stripe(op) || mirror_num > 1)) {
			/* push stripe_nr back to the start of the full stripe */
			stripe_nr = div64_u64(raid56_full_stripe_start,
					stripe_len * nr_data_stripes(map));

			/* RAID[56] write or recovery. Return all stripes */
			num_stripes = map->num_stripes;
			max_errors = nr_parity_stripes(map);

			*length = map->stripe_len;
			stripe_index = 0;
			stripe_offset = 0;
		} else {
			/*
			 * Mirror #0 or #1 means the original data block.
			 * Mirror #2 is RAID5 parity block.
			 * Mirror #3 is RAID6 Q block.
			 */
			stripe_nr = div_u64_rem(stripe_nr,
					nr_data_stripes(map), &stripe_index);
			if (mirror_num > 1)
				stripe_index = nr_data_stripes(map) +
						mirror_num - 2;

			/* We distribute the parity blocks across stripes */
			div_u64_rem(stripe_nr + stripe_index, map->num_stripes,
					&stripe_index);
			if (!need_full_stripe(op) && mirror_num <= 1)
				mirror_num = 1;
		}
	} else {
		/*
		 * after this, stripe_nr is the number of stripes on this
		 * device we have to walk to find the data, and stripe_index is
		 * the number of our device in the stripe array
		 */
		stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
				&stripe_index);
		mirror_num = stripe_index + 1;
	}
	if (stripe_index >= map->num_stripes) {
		btrfs_crit(fs_info,
			   "stripe index math went horribly wrong, got stripe_index=%u, num_stripes=%u",
			   stripe_index, map->num_stripes);
		ret = -EINVAL;
		goto out;
	}

	num_alloc_stripes = num_stripes;
	if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL) {
		if (op == BTRFS_MAP_WRITE)
			num_alloc_stripes <<= 1;
		if (op == BTRFS_MAP_GET_READ_MIRRORS)
			num_alloc_stripes++;
		tgtdev_indexes = num_stripes;
	}

	bbio = alloc_btrfs_bio(num_alloc_stripes, tgtdev_indexes);
	if (!bbio) {
		ret = -ENOMEM;
		goto out;
	}
	if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL)
		bbio->tgtdev_map = (int *)(bbio->stripes + num_alloc_stripes);

	/* build raid_map */
	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK && need_raid_map &&
	    (need_full_stripe(op) || mirror_num > 1)) {
		u64 tmp;
		unsigned rot;

		bbio->raid_map = (u64 *)((void *)bbio->stripes +
				 sizeof(struct btrfs_bio_stripe) *
				 num_alloc_stripes +
				 sizeof(int) * tgtdev_indexes);

		/* Work out the disk rotation on this stripe-set */
		div_u64_rem(stripe_nr, num_stripes, &rot);

		/* Fill in the logical address of each stripe */
		tmp = stripe_nr * nr_data_stripes(map);
		for (i = 0; i < nr_data_stripes(map); i++)
			bbio->raid_map[(i+rot) % num_stripes] =
				em->start + (tmp + i) * map->stripe_len;

		bbio->raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
		if (map->type & BTRFS_BLOCK_GROUP_RAID6)
			bbio->raid_map[(i+rot+1) % num_stripes] =
				RAID6_Q_STRIPE;
	}


	for (i = 0; i < num_stripes; i++) {
		bbio->stripes[i].physical =
			map->stripes[stripe_index].physical +
			stripe_offset +
			stripe_nr * map->stripe_len;
		bbio->stripes[i].dev =
			map->stripes[stripe_index].dev;
		stripe_index++;
	}

	if (need_full_stripe(op))
		max_errors = btrfs_chunk_max_errors(map);

	if (bbio->raid_map)
		sort_parity_stripes(bbio, num_stripes);

	if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL &&
	    need_full_stripe(op)) {
		handle_ops_on_dev_replace(op, &bbio, dev_replace, &num_stripes,
					  &max_errors);
	}

	*bbio_ret = bbio;
	bbio->map_type = map->type;
	bbio->num_stripes = num_stripes;
	bbio->max_errors = max_errors;
	bbio->mirror_num = mirror_num;

	/*
	 * this is the case that REQ_READ && dev_replace_is_ongoing &&
	 * mirror_num == num_stripes + 1 && dev_replace target drive is
	 * available as a mirror
	 */
	if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
		WARN_ON(num_stripes > 1);
		bbio->stripes[0].dev = dev_replace->tgtdev;
		bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
		bbio->mirror_num = map->num_stripes + 1;
	}
out:
	if (dev_replace_is_ongoing) {
		lockdep_assert_held(&dev_replace->rwsem);
		/* Unlock and let waiting writers proceed */
		up_read(&dev_replace->rwsem);
	}
	free_extent_map(em);
	return ret;
}

Project: linux
File: volumes.c

static int chunk_usage_filter(struct btrfs_fs_info *fs_info,
		u64 chunk_offset, struct btrfs_balance_args *bargs)
{
	struct btrfs_block_group_cache *cache;
	u64 chunk_used, user_thresh;
	int ret = 1;

	cache = btrfs_lookup_block_group(fs_info, chunk_offset);
	chunk_used = btrfs_block_group_used(&cache->item);

	if (bargs->usage_min == 0)
		user_thresh = 1;
	else if (bargs->usage > 100)
		user_thresh = cache->key.offset;
	else
		user_thresh = div_factor_fine(cache->key.offset,
					      bargs->usage);

	if (chunk_used < user_thresh)
		ret = 0;

	btrfs_put_block_group(cache);
	return ret;
}

Project: linux
File: volumes.c

static struct btrfs_device *add_missing_dev(struct btrfs_fs_devices *fs_devices,
					    u64 devid, u8 *dev_uuid)
{
	struct btrfs_device *device;

	device = btrfs_alloc_device(NULL, &devid, dev_uuid);
	if (IS_ERR(device))
		return device;

	list_add(&device->dev_list, &fs_devices->devices);
	device->fs_devices = fs_devices;
	fs_devices->num_devices++;

	set_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
	fs_devices->missing_devices++;

	return device;
}

Project: linux
File: dev-replace.c

int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
{
	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
	struct btrfs_device *tgt_device = NULL;
	struct btrfs_device *src_device = NULL;
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = fs_info->tree_root;
	int result;
	int ret;

	if (sb_rdonly(fs_info->sb))
		return -EROFS;

	mutex_lock(&dev_replace->lock_finishing_cancel_unmount);
	down_write(&dev_replace->rwsem);
	switch (dev_replace->replace_state) {
	case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:
	case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
	case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:
		result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
		up_write(&dev_replace->rwsem);
		break;
	case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
		tgt_device = dev_replace->tgtdev;
		src_device = dev_replace->srcdev;
		up_write(&dev_replace->rwsem);
		ret = btrfs_scrub_cancel(fs_info);
		if (ret < 0) {
			result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;
		} else {
			result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
			/*
			 * btrfs_dev_replace_finishing() will handle the
			 * cleanup part
			 */
			btrfs_info_in_rcu(fs_info,
				"dev_replace from %s (devid %llu) to %s canceled",
				btrfs_dev_name(src_device), src_device->devid,
				btrfs_dev_name(tgt_device));
		}
		break;
	case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
		/*
		 * Scrub doing the replace isn't running so we need to do the
		 * cleanup step of btrfs_dev_replace_finishing() here
		 */
		result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
		tgt_device = dev_replace->tgtdev;
		src_device = dev_replace->srcdev;
		dev_replace->tgtdev = NULL;
		dev_replace->srcdev = NULL;
		dev_replace->replace_state =
				BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED;
		dev_replace->time_stopped = ktime_get_real_seconds();
		dev_replace->item_needs_writeback = 1;

		up_write(&dev_replace->rwsem);

		/* Scrub for replace must not be running in suspended state */
		ret = btrfs_scrub_cancel(fs_info);
		ASSERT(ret != -ENOTCONN);

		trans = btrfs_start_transaction(root, 0);
		if (IS_ERR(trans)) {
			mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
			return PTR_ERR(trans);
		}
		ret = btrfs_commit_transaction(trans);
		WARN_ON(ret);

		btrfs_info_in_rcu(fs_info,
		"suspended dev_replace from %s (devid %llu) to %s canceled",
			btrfs_dev_name(src_device), src_device->devid,
			btrfs_dev_name(tgt_device));

		if (tgt_device)
			btrfs_destroy_dev_replace_tgtdev(tgt_device);
		break;
	default:
		result = -EINVAL;
	}

	mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);
	return result;
}

Project: linux
File: volumes.c

int btrfs_bg_type_to_factor(u64 flags)
{
	if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
		     BTRFS_BLOCK_GROUP_RAID10))
		return 2;
	return 1;
}

Project: linux
File: volumes.c

static int del_balance_item(struct btrfs_fs_info *fs_info)
{
	struct btrfs_root *root = fs_info->tree_root;
	struct btrfs_trans_handle *trans;
	struct btrfs_path *path;
	struct btrfs_key key;
	int ret, err;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	trans = btrfs_start_transaction(root, 0);
	if (IS_ERR(trans)) {
		btrfs_free_path(path);
		return PTR_ERR(trans);
	}

	key.objectid = BTRFS_BALANCE_OBJECTID;
	key.type = BTRFS_TEMPORARY_ITEM_KEY;
	key.offset = 0;

	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	if (ret < 0)
		goto out;
	if (ret > 0) {
		ret = -ENOENT;
		goto out;
	}

	ret = btrfs_del_item(trans, root, path);
out:
	btrfs_free_path(path);
	err = btrfs_commit_transaction(trans);
	if (err && !ret)
		ret = err;
	return ret;
}

Project: linux
File: volumes.c

int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
{
	struct extent_map *em;
	struct map_lookup *map;
	int ret;

	em = btrfs_get_chunk_map(fs_info, logical, len);
	if (IS_ERR(em))
		/*
		 * We could return errors for these cases, but that could get
		 * ugly and we'd probably do the same thing which is just not do
		 * anything else and exit, so return 1 so the callers don't try
		 * to use other copies.
		 */
		return 1;

	map = em->map_lookup;
	if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
		ret = map->num_stripes;
	else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
		ret = map->sub_stripes;
	else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
		ret = 2;
	else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
		/*
		 * There could be two corrupted data stripes, we need
		 * to loop retry in order to rebuild the correct data.
		 *
		 * Fail a stripe at a time on every retry except the
		 * stripe under reconstruction.
		 */
		ret = map->num_stripes;
	else
		ret = 1;
	free_extent_map(em);

	down_read(&fs_info->dev_replace.rwsem);
	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace) &&
	    fs_info->dev_replace.tgtdev)
		ret++;
	up_read(&fs_info->dev_replace.rwsem);

	return ret;
}

Project: linux
File: scrub.c

static u64 get_full_stripe_logical(struct btrfs_block_group_cache *cache,
				   u64 bytenr)
{
	u64 ret;

	/*
	 * Due to chunk item size limit, full stripe length should not be
	 * larger than U32_MAX. Just a sanity check here.
	 */
	WARN_ON_ONCE(cache->full_stripe_len >= U32_MAX);

	/*
	 * round_down() can only handle power of 2, while RAID56 full
	 * stripe length can be 64KiB * n, so we need to manually round down.
	 */
	ret = div64_u64(bytenr - cache->key.objectid, cache->full_stripe_len) *
		cache->full_stripe_len + cache->key.objectid;
	return ret;
}

Project: linux
File: scrub.c

static void scrub_parity_get(struct scrub_parity *sparity)
{
	refcount_inc(&sparity->refs);
}

Project: linux
File: ioctl.c

static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
		unsigned int flags)
{
	if (S_ISDIR(inode->i_mode))
		return flags;
	else if (S_ISREG(inode->i_mode))
		return flags & ~FS_DIRSYNC_FL;
	else
		return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
}

Project: linux
File: scrub.c

static void scrub_parity_bio_endio(struct bio *bio)
{
	struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
	struct btrfs_fs_info *fs_info = sparity->sctx->fs_info;

	if (bio->bi_status)
		bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
			  sparity->nsectors);

	bio_put(bio);

	btrfs_init_work(&sparity->work, btrfs_scrubparity_helper,
			scrub_parity_bio_endio_worker, NULL, NULL);
	btrfs_queue_work(fs_info->scrub_parity_workers, &sparity->work);
}

Project: linux
File: volumes.c

int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
{
	mutex_lock(&fs_info->balance_mutex);
	if (!fs_info->balance_ctl) {
		mutex_unlock(&fs_info->balance_mutex);
		return -ENOTCONN;
	}

	/*
	 * A paused balance with the item stored on disk can be resumed at
	 * mount time if the mount is read-write. Otherwise it's still paused
	 * and we must not allow cancelling as it deletes the item.
	 */
	if (sb_rdonly(fs_info->sb)) {
		mutex_unlock(&fs_info->balance_mutex);
		return -EROFS;
	}

	atomic_inc(&fs_info->balance_cancel_req);
	/*
	 * if we are running just wait and return, balance item is
	 * deleted in btrfs_balance in this case
	 */
	if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
		mutex_unlock(&fs_info->balance_mutex);
		wait_event(fs_info->balance_wait_q,
			   !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
		mutex_lock(&fs_info->balance_mutex);
	} else {
		mutex_unlock(&fs_info->balance_mutex);
		/*
		 * Lock released to allow other waiters to continue, we'll
		 * reexamine the status again.
		 */
		mutex_lock(&fs_info->balance_mutex);

		if (fs_info->balance_ctl) {
			reset_balance_state(fs_info);
			clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
			btrfs_info(fs_info, "balance: canceled");
		}
	}

	BUG_ON(fs_info->balance_ctl ||
		test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
	atomic_dec(&fs_info->balance_cancel_req);
	mutex_unlock(&fs_info->balance_mutex);
	return 0;
}

Project: linux
File: volumes.c

static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
{
	int i;

	for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
		btrfs_dev_stat_reset(dev, i);
}

Project: linux
File: volumes.c

static int btrfs_may_alloc_data_chunk(struct btrfs_fs_info *fs_info,
				      u64 chunk_offset)
{
	struct btrfs_block_group_cache *cache;
	u64 bytes_used;
	u64 chunk_type;

	cache = btrfs_lookup_block_group(fs_info, chunk_offset);
	ASSERT(cache);
	chunk_type = cache->flags;
	btrfs_put_block_group(cache);

	if (chunk_type & BTRFS_BLOCK_GROUP_DATA) {
		spin_lock(&fs_info->data_sinfo->lock);
		bytes_used = fs_info->data_sinfo->bytes_used;
		spin_unlock(&fs_info->data_sinfo->lock);

		if (!bytes_used) {
			struct btrfs_trans_handle *trans;
			int ret;

			trans =	btrfs_join_transaction(fs_info->tree_root);
			if (IS_ERR(trans))
				return PTR_ERR(trans);

			ret = btrfs_force_chunk_alloc(trans,
						      BTRFS_BLOCK_GROUP_DATA);
			btrfs_end_transaction(trans);
			if (ret < 0)
				return ret;

			btrfs_add_raid_kobjects(fs_info);

			return 1;
		}
	}
	return 0;
}

Project: linux
File: ioctl.c

static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
{
	struct btrfs_inode *binode = BTRFS_I(file_inode(file));
	unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags);

	if (copy_to_user(arg, &flags, sizeof(flags)))
		return -EFAULT;
	return 0;
}

Project: linux
File: scrub.c

static void scrub_missing_raid56_worker(struct btrfs_work *work)
{
	struct scrub_block *sblock = container_of(work, struct scrub_block, work);
	struct scrub_ctx *sctx = sblock->sctx;
	struct btrfs_fs_info *fs_info = sctx->fs_info;
	u64 logical;
	struct btrfs_device *dev;

	logical = sblock->pagev[0]->logical;
	dev = sblock->pagev[0]->dev;

	if (sblock->no_io_error_seen)
		scrub_recheck_block_checksum(sblock);

	if (!sblock->no_io_error_seen) {
		spin_lock(&sctx->stat_lock);
		sctx->stat.read_errors++;
		spin_unlock(&sctx->stat_lock);
		btrfs_err_rl_in_rcu(fs_info,
			"IO error rebuilding logical %llu for dev %s",
			logical, rcu_str_deref(dev->name));
	} else if (sblock->header_error || sblock->checksum_error) {
		spin_lock(&sctx->stat_lock);
		sctx->stat.uncorrectable_errors++;
		spin_unlock(&sctx->stat_lock);
		btrfs_err_rl_in_rcu(fs_info,
			"failed to rebuild valid logical %llu for dev %s",
			logical, rcu_str_deref(dev->name));
	} else {
		scrub_write_block_to_dev_replace(sblock);
	}

	scrub_block_put(sblock);

	if (sctx->is_dev_replace && sctx->flush_all_writes) {
		mutex_lock(&sctx->wr_lock);
		scrub_wr_submit(sctx);
		mutex_unlock(&sctx->wr_lock);
	}

	scrub_pending_bio_dec(sctx);
}

Project: linux
File: volumes.c

int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
			struct btrfs_fs_info *fs_info)
{
	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
	struct btrfs_device *device;
	int stats_cnt;
	int ret = 0;

	mutex_lock(&fs_devices->device_list_mutex);
	list_for_each_entry(device, &fs_devices->devices, dev_list) {
		stats_cnt = atomic_read(&device->dev_stats_ccnt);
		if (!device->dev_stats_valid || stats_cnt == 0)
			continue;


		/*
		 * There is a LOAD-LOAD control dependency between the value of
		 * dev_stats_ccnt and updating the on-disk values which requires
		 * reading the in-memory counters. Such control dependencies
		 * require explicit read memory barriers.
		 *
		 * This memory barriers pairs with smp_mb__before_atomic in
		 * btrfs_dev_stat_inc/btrfs_dev_stat_set and with the full
		 * barrier implied by atomic_xchg in
		 * btrfs_dev_stats_read_and_reset
		 */
		smp_rmb();

		ret = update_dev_stat_item(trans, device);
		if (!ret)
			atomic_sub(stats_cnt, &device->dev_stats_ccnt);
	}
	mutex_unlock(&fs_devices->device_list_mutex);

	return ret;
}

Project: linux
File: volumes.c

static int open_fs_devices(struct btrfs_fs_devices *fs_devices,
				fmode_t flags, void *holder)
{
	struct btrfs_device *device;
	struct btrfs_device *latest_dev = NULL;
	int ret = 0;

	flags |= FMODE_EXCL;

	list_for_each_entry(device, &fs_devices->devices, dev_list) {
		/* Just open everything we can; ignore failures here */
		if (btrfs_open_one_device(fs_devices, device, flags, holder))
			continue;

		if (!latest_dev ||
		    device->generation > latest_dev->generation)
			latest_dev = device;
	}
	if (fs_devices->open_devices == 0) {
		ret = -EINVAL;
		goto out;
	}
	fs_devices->opened = 1;
	fs_devices->latest_bdev = latest_dev->bdev;
	fs_devices->total_rw_bytes = 0;
out:
	return ret;
}

Project: linux
File: scrub.c

static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
					     struct scrub_block *sblock_good)
{
	int page_num;
	int ret = 0;

	for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
		int ret_sub;

		ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
							   sblock_good,
							   page_num, 1);
		if (ret_sub)
			ret = ret_sub;
	}

	return ret;
}

Project: linux
File: volumes.c

static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
{
	struct btrfs_fs_devices *fs_devices;
	struct btrfs_device *device;
	struct btrfs_device *orig_dev;

	fs_devices = alloc_fs_devices(orig->fsid, NULL);
	if (IS_ERR(fs_devices))
		return fs_devices;

	mutex_lock(&orig->device_list_mutex);
	fs_devices->total_devices = orig->total_devices;

	/* We have held the volume lock, it is safe to get the devices. */
	list_for_each_entry(orig_dev, &orig->devices, dev_list) {
		struct rcu_string *name;

		device = btrfs_alloc_device(NULL, &orig_dev->devid,
					    orig_dev->uuid);
		if (IS_ERR(device))
			goto error;

		/*
		 * This is ok to do without rcu read locked because we hold the
		 * uuid mutex so nothing we touch in here is going to disappear.
		 */
		if (orig_dev->name) {
			name = rcu_string_strdup(orig_dev->name->str,
					GFP_KERNEL);
			if (!name) {
				btrfs_free_device(device);
				goto error;
			}
			rcu_assign_pointer(device->name, name);
		}

		list_add(&device->dev_list, &fs_devices->devices);
		device->fs_devices = fs_devices;
		fs_devices->num_devices++;
	}
	mutex_unlock(&orig->device_list_mutex);
	return fs_devices;
error:
	mutex_unlock(&orig->device_list_mutex);
	free_fs_devices(fs_devices);
	return ERR_PTR(-ENOMEM);
}

Project: linux
File: volumes.c

static void submit_stripe_bio(struct btrfs_bio *bbio, struct bio *bio,
			      u64 physical, int dev_nr, int async)
{
	struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
	struct btrfs_fs_info *fs_info = bbio->fs_info;

	bio->bi_private = bbio;
	btrfs_io_bio(bio)->stripe_index = dev_nr;
	bio->bi_end_io = btrfs_end_bio;
	bio->bi_iter.bi_sector = physical >> 9;
	btrfs_debug_in_rcu(fs_info,
	"btrfs_map_bio: rw %d 0x%x, sector=%llu, dev=%lu (%s id %llu), size=%u",
		bio_op(bio), bio->bi_opf, (u64)bio->bi_iter.bi_sector,
		(u_long)dev->bdev->bd_dev, rcu_str_deref(dev->name), dev->devid,
		bio->bi_iter.bi_size);
	bio_set_dev(bio, dev->bdev);

	btrfs_bio_counter_inc_noblocked(fs_info);

	if (async)
		btrfs_schedule_bio(dev, bio);
	else
		btrfsic_submit_bio(bio);
}

Project: linux
File: scrub.c

static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
						  struct map_lookup *map,
						  struct btrfs_device *sdev,
						  struct btrfs_path *path,
						  u64 logic_start,
						  u64 logic_end)
{
	struct btrfs_fs_info *fs_info = sctx->fs_info;
	struct btrfs_root *root = fs_info->extent_root;
	struct btrfs_root *csum_root = fs_info->csum_root;
	struct btrfs_extent_item *extent;
	struct btrfs_bio *bbio = NULL;
	u64 flags;
	int ret;
	int slot;
	struct extent_buffer *l;
	struct btrfs_key key;
	u64 generation;
	u64 extent_logical;
	u64 extent_physical;
	u64 extent_len;
	u64 mapped_length;
	struct btrfs_device *extent_dev;
	struct scrub_parity *sparity;
	int nsectors;
	int bitmap_len;
	int extent_mirror_num;
	int stop_loop = 0;

	nsectors = div_u64(map->stripe_len, fs_info->sectorsize);
	bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
	sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
			  GFP_NOFS);
	if (!sparity) {
		spin_lock(&sctx->stat_lock);
		sctx->stat.malloc_errors++;
		spin_unlock(&sctx->stat_lock);
		return -ENOMEM;
	}

	sparity->stripe_len = map->stripe_len;
	sparity->nsectors = nsectors;
	sparity->sctx = sctx;
	sparity->scrub_dev = sdev;
	sparity->logic_start = logic_start;
	sparity->logic_end = logic_end;
	refcount_set(&sparity->refs, 1);
	INIT_LIST_HEAD(&sparity->spages);
	sparity->dbitmap = sparity->bitmap;
	sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;

	ret = 0;
	while (logic_start < logic_end) {
		if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
			key.type = BTRFS_METADATA_ITEM_KEY;
		else
			key.type = BTRFS_EXTENT_ITEM_KEY;
		key.objectid = logic_start;
		key.offset = (u64)-1;

		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		if (ret < 0)
			goto out;

		if (ret > 0) {
			ret = btrfs_previous_extent_item(root, path, 0);
			if (ret < 0)
				goto out;
			if (ret > 0) {
				btrfs_release_path(path);
				ret = btrfs_search_slot(NULL, root, &key,
							path, 0, 0);
				if (ret < 0)
					goto out;
			}
		}

		stop_loop = 0;
		while (1) {
			u64 bytes;

			l = path->nodes[0];
			slot = path->slots[0];
			if (slot >= btrfs_header_nritems(l)) {
				ret = btrfs_next_leaf(root, path);
				if (ret == 0)
					continue;
				if (ret < 0)
					goto out;

				stop_loop = 1;
				break;
			}
			btrfs_item_key_to_cpu(l, &key, slot);

			if (key.type != BTRFS_EXTENT_ITEM_KEY &&
			    key.type != BTRFS_METADATA_ITEM_KEY)
				goto next;

			if (key.type == BTRFS_METADATA_ITEM_KEY)
				bytes = fs_info->nodesize;
			else
				bytes = key.offset;

			if (key.objectid + bytes <= logic_start)
				goto next;

			if (key.objectid >= logic_end) {
				stop_loop = 1;
				break;
			}

			while (key.objectid >= logic_start + map->stripe_len)
				logic_start += map->stripe_len;

			extent = btrfs_item_ptr(l, slot,
						struct btrfs_extent_item);
			flags = btrfs_extent_flags(l, extent);
			generation = btrfs_extent_generation(l, extent);

			if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
			    (key.objectid < logic_start ||
			     key.objectid + bytes >
			     logic_start + map->stripe_len)) {
				btrfs_err(fs_info,
					  "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
					  key.objectid, logic_start);
				spin_lock(&sctx->stat_lock);
				sctx->stat.uncorrectable_errors++;
				spin_unlock(&sctx->stat_lock);
				goto next;
			}
again:
			extent_logical = key.objectid;
			extent_len = bytes;

			if (extent_logical < logic_start) {
				extent_len -= logic_start - extent_logical;
				extent_logical = logic_start;
			}

			if (extent_logical + extent_len >
			    logic_start + map->stripe_len)
				extent_len = logic_start + map->stripe_len -
					     extent_logical;

			scrub_parity_mark_sectors_data(sparity, extent_logical,
						       extent_len);

			mapped_length = extent_len;
			bbio = NULL;
			ret = btrfs_map_block(fs_info, BTRFS_MAP_READ,
					extent_logical, &mapped_length, &bbio,
					0);
			if (!ret) {
				if (!bbio || mapped_length < extent_len)
					ret = -EIO;
			}
			if (ret) {
				btrfs_put_bbio(bbio);
				goto out;
			}
			extent_physical = bbio->stripes[0].physical;
			extent_mirror_num = bbio->mirror_num;
			extent_dev = bbio->stripes[0].dev;
			btrfs_put_bbio(bbio);

			ret = btrfs_lookup_csums_range(csum_root,
						extent_logical,
						extent_logical + extent_len - 1,
						&sctx->csum_list, 1);
			if (ret)
				goto out;

			ret = scrub_extent_for_parity(sparity, extent_logical,
						      extent_len,
						      extent_physical,
						      extent_dev, flags,
						      generation,
						      extent_mirror_num);

			scrub_free_csums(sctx);

			if (ret)
				goto out;

			if (extent_logical + extent_len <
			    key.objectid + bytes) {
				logic_start += map->stripe_len;

				if (logic_start >= logic_end) {
					stop_loop = 1;
					break;
				}

				if (logic_start < key.objectid + bytes) {
					cond_resched();
					goto again;
				}
			}
next:
			path->slots[0]++;
		}

		btrfs_release_path(path);

		if (stop_loop)
			break;

		logic_start += map->stripe_len;
	}
out:
	if (ret < 0)
		scrub_parity_mark_sectors_error(sparity, logic_start,
						logic_end - logic_start);
	scrub_parity_put(sparity);
	scrub_submit(sctx);
	mutex_lock(&sctx->wr_lock);
	scrub_wr_submit(sctx);
	mutex_unlock(&sctx->wr_lock);

	btrfs_release_path(path);
	return ret < 0 ? ret : 0;
}

Project: linux
File: volumes.c

static void btrfs_kobject_uevent(struct block_device *bdev,
				 enum kobject_action action)
{
	int ret;

	ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
	if (ret)
		pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
			action,
			kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
			&disk_to_dev(bdev->bd_disk)->kobj);
}

Project: linux
File: ioctl.c

static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
{
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
	struct extent_map *em = NULL;
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
	u64 end;

	read_lock(&em_tree->lock);
	em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
	read_unlock(&em_tree->lock);

	if (em) {
		end = extent_map_end(em);
		free_extent_map(em);
		if (end - offset > thresh)
			return 0;
	}
	/* if we already have a nice delalloc here, just stop */
	thresh /= 2;
	end = count_range_bits(io_tree, &offset, offset + thresh,
			       thresh, EXTENT_DELALLOC, 1);
	if (end >= thresh)
		return 0;
	return 1;
}

Project: linux
File: volumes.c

static void btrfs_end_bio(struct bio *bio)
{
	struct btrfs_bio *bbio = bio->bi_private;
	int is_orig_bio = 0;

	if (bio->bi_status) {
		atomic_inc(&bbio->error);
		if (bio->bi_status == BLK_STS_IOERR ||
		    bio->bi_status == BLK_STS_TARGET) {
			unsigned int stripe_index =
				btrfs_io_bio(bio)->stripe_index;
			struct btrfs_device *dev;

			BUG_ON(stripe_index >= bbio->num_stripes);
			dev = bbio->stripes[stripe_index].dev;
			if (dev->bdev) {
				if (bio_op(bio) == REQ_OP_WRITE)
					btrfs_dev_stat_inc_and_print(dev,
						BTRFS_DEV_STAT_WRITE_ERRS);
				else
					btrfs_dev_stat_inc_and_print(dev,
						BTRFS_DEV_STAT_READ_ERRS);
				if (bio->bi_opf & REQ_PREFLUSH)
					btrfs_dev_stat_inc_and_print(dev,
						BTRFS_DEV_STAT_FLUSH_ERRS);
			}
		}
	}

	if (bio == bbio->orig_bio)
		is_orig_bio = 1;

	btrfs_bio_counter_dec(bbio->fs_info);

	if (atomic_dec_and_test(&bbio->stripes_pending)) {
		if (!is_orig_bio) {
			bio_put(bio);
			bio = bbio->orig_bio;
		}

		btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
		/* only send an error to the higher layers if it is
		 * beyond the tolerance of the btrfs bio
		 */
		if (atomic_read(&bbio->error) > bbio->max_errors) {
			bio->bi_status = BLK_STS_IOERR;
		} else {
			/*
			 * this bio is actually up to date, we didn't
			 * go over the max number of errors
			 */
			bio->bi_status = BLK_STS_OK;
		}

		btrfs_end_bbio(bbio, bio);
	} else if (!is_orig_bio) {
		bio_put(bio);
	}
}

Project: linux
File: volumes.c

static int __btrfs_map_block_for_discard(struct btrfs_fs_info *fs_info,
					 u64 logical, u64 length,
					 struct btrfs_bio **bbio_ret)
{
	struct extent_map *em;
	struct map_lookup *map;
	struct btrfs_bio *bbio;
	u64 offset;
	u64 stripe_nr;
	u64 stripe_nr_end;
	u64 stripe_end_offset;
	u64 stripe_cnt;
	u64 stripe_len;
	u64 stripe_offset;
	u64 num_stripes;
	u32 stripe_index;
	u32 factor = 0;
	u32 sub_stripes = 0;
	u64 stripes_per_dev = 0;
	u32 remaining_stripes = 0;
	u32 last_stripe = 0;
	int ret = 0;
	int i;

	/* discard always return a bbio */
	ASSERT(bbio_ret);

	em = btrfs_get_chunk_map(fs_info, logical, length);
	if (IS_ERR(em))
		return PTR_ERR(em);

	map = em->map_lookup;
	/* we don't discard raid56 yet */
	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
		ret = -EOPNOTSUPP;
		goto out;
	}

	offset = logical - em->start;
	length = min_t(u64, em->len - offset, length);

	stripe_len = map->stripe_len;
	/*
	 * stripe_nr counts the total number of stripes we have to stride
	 * to get to this block
	 */
	stripe_nr = div64_u64(offset, stripe_len);

	/* stripe_offset is the offset of this block in its stripe */
	stripe_offset = offset - stripe_nr * stripe_len;

	stripe_nr_end = round_up(offset + length, map->stripe_len);
	stripe_nr_end = div64_u64(stripe_nr_end, map->stripe_len);
	stripe_cnt = stripe_nr_end - stripe_nr;
	stripe_end_offset = stripe_nr_end * map->stripe_len -
			    (offset + length);
	/*
	 * after this, stripe_nr is the number of stripes on this
	 * device we have to walk to find the data, and stripe_index is
	 * the number of our device in the stripe array
	 */
	num_stripes = 1;
	stripe_index = 0;
	if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
			 BTRFS_BLOCK_GROUP_RAID10)) {
		if (map->type & BTRFS_BLOCK_GROUP_RAID0)
			sub_stripes = 1;
		else
			sub_stripes = map->sub_stripes;

		factor = map->num_stripes / sub_stripes;
		num_stripes = min_t(u64, map->num_stripes,
				    sub_stripes * stripe_cnt);
		stripe_nr = div_u64_rem(stripe_nr, factor, &stripe_index);
		stripe_index *= sub_stripes;
		stripes_per_dev = div_u64_rem(stripe_cnt, factor,
					      &remaining_stripes);
		div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
		last_stripe *= sub_stripes;
	} else if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
				BTRFS_BLOCK_GROUP_DUP)) {
		num_stripes = map->num_stripes;
	} else {
		stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
					&stripe_index);
	}

	bbio = alloc_btrfs_bio(num_stripes, 0);
	if (!bbio) {
		ret = -ENOMEM;
		goto out;
	}

	for (i = 0; i < num_stripes; i++) {
		bbio->stripes[i].physical =
			map->stripes[stripe_index].physical +
			stripe_offset + stripe_nr * map->stripe_len;
		bbio->stripes[i].dev = map->stripes[stripe_index].dev;

		if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
				 BTRFS_BLOCK_GROUP_RAID10)) {
			bbio->stripes[i].length = stripes_per_dev *
				map->stripe_len;

			if (i / sub_stripes < remaining_stripes)
				bbio->stripes[i].length +=
					map->stripe_len;

			/*
			 * Special for the first stripe and
			 * the last stripe:
			 *
			 * |-------|...|-------|
			 *     |----------|
			 *    off     end_off
			 */
			if (i < sub_stripes)
				bbio->stripes[i].length -=
					stripe_offset;

			if (stripe_index >= last_stripe &&
			    stripe_index <= (last_stripe +
					     sub_stripes - 1))
				bbio->stripes[i].length -=
					stripe_end_offset;

			if (i == sub_stripes - 1)
				stripe_offset = 0;
		} else {
			bbio->stripes[i].length = length;
		}

		stripe_index++;
		if (stripe_index == map->num_stripes) {
			stripe_index = 0;
			stripe_nr++;
		}
	}

	*bbio_ret = bbio;
	bbio->map_type = map->type;
	bbio->num_stripes = num_stripes;
out:
	free_extent_map(em);
	return ret;
}

Project: linux
File: volumes.c

int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
		       fmode_t flags, void *holder)
{
	int ret;

	lockdep_assert_held(&uuid_mutex);

	mutex_lock(&fs_devices->device_list_mutex);
	if (fs_devices->opened) {
		fs_devices->opened++;
		ret = 0;
	} else {
		list_sort(NULL, &fs_devices->devices, devid_cmp);
		ret = open_fs_devices(fs_devices, flags, holder);
	}
	mutex_unlock(&fs_devices->device_list_mutex);

	return ret;
}

Project: linux
File: volumes.c

int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
{
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct btrfs_root *dev_root = fs_info->dev_root;
	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
	struct extent_buffer *eb;
	int slot;
	int ret = 0;
	struct btrfs_device *device;
	struct btrfs_path *path = NULL;
	int i;

	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}

	mutex_lock(&fs_devices->device_list_mutex);
	list_for_each_entry(device, &fs_devices->devices, dev_list) {
		int item_size;
		struct btrfs_dev_stats_item *ptr;

		key.objectid = BTRFS_DEV_STATS_OBJECTID;
		key.type = BTRFS_PERSISTENT_ITEM_KEY;
		key.offset = device->devid;
		ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
		if (ret) {
			__btrfs_reset_dev_stats(device);
			device->dev_stats_valid = 1;
			btrfs_release_path(path);
			continue;
		}
		slot = path->slots[0];
		eb = path->nodes[0];
		btrfs_item_key_to_cpu(eb, &found_key, slot);
		item_size = btrfs_item_size_nr(eb, slot);

		ptr = btrfs_item_ptr(eb, slot,
				     struct btrfs_dev_stats_item);

		for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
			if (item_size >= (1 + i) * sizeof(__le64))
				btrfs_dev_stat_set(device, i,
					btrfs_dev_stats_value(eb, ptr, i));
			else
				btrfs_dev_stat_reset(device, i);
		}

		device->dev_stats_valid = 1;
		btrfs_dev_stat_print_on_load(device);
		btrfs_release_path(path);
	}
	mutex_unlock(&fs_devices->device_list_mutex);

out:
	btrfs_free_path(path);
	return ret < 0 ? ret : 0;
}

Project: linux
File: ioctl.c

static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
{
	struct inode *inode = file_inode(file);
	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_root *new_root;
	struct btrfs_dir_item *di;
	struct btrfs_trans_handle *trans;
	struct btrfs_path *path;
	struct btrfs_key location;
	struct btrfs_disk_key disk_key;
	u64 objectid = 0;
	u64 dir_id;
	int ret;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	ret = mnt_want_write_file(file);
	if (ret)
		return ret;

	if (copy_from_user(&objectid, argp, sizeof(objectid))) {
		ret = -EFAULT;
		goto out;
	}

	if (!objectid)
		objectid = BTRFS_FS_TREE_OBJECTID;

	location.objectid = objectid;
	location.type = BTRFS_ROOT_ITEM_KEY;
	location.offset = (u64)-1;

	new_root = btrfs_read_fs_root_no_name(fs_info, &location);
	if (IS_ERR(new_root)) {
		ret = PTR_ERR(new_root);
		goto out;
	}
	if (!is_fstree(new_root->root_key.objectid)) {
		ret = -ENOENT;
		goto out;
	}

	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}
	path->leave_spinning = 1;

	trans = btrfs_start_transaction(root, 1);
	if (IS_ERR(trans)) {
		btrfs_free_path(path);
		ret = PTR_ERR(trans);
		goto out;
	}

	dir_id = btrfs_super_root_dir(fs_info->super_copy);
	di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
				   dir_id, "default", 7, 1);
	if (IS_ERR_OR_NULL(di)) {
		btrfs_free_path(path);
		btrfs_end_transaction(trans);
		btrfs_err(fs_info,
			  "Umm, you don't have the default diritem, this isn't going to work");
		ret = -ENOENT;
		goto out;
	}

	btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
	btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
	btrfs_mark_buffer_dirty(path->nodes[0]);
	btrfs_free_path(path);

	btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
	btrfs_end_transaction(trans);
out:
	mnt_drop_write_file(file);
	return ret;
}

Project: linux
File: volumes.c

static int btrfs_uuid_scan_kthread(void *data)
{
	struct btrfs_fs_info *fs_info = data;
	struct btrfs_root *root = fs_info->tree_root;
	struct btrfs_key key;
	struct btrfs_path *path = NULL;
	int ret = 0;
	struct extent_buffer *eb;
	int slot;
	struct btrfs_root_item root_item;
	u32 item_size;
	struct btrfs_trans_handle *trans = NULL;

	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}

	key.objectid = 0;
	key.type = BTRFS_ROOT_ITEM_KEY;
	key.offset = 0;

	while (1) {
		ret = btrfs_search_forward(root, &key, path,
				BTRFS_OLDEST_GENERATION);
		if (ret) {
			if (ret > 0)
				ret = 0;
			break;
		}

		if (key.type != BTRFS_ROOT_ITEM_KEY ||
		    (key.objectid < BTRFS_FIRST_FREE_OBJECTID &&
		     key.objectid != BTRFS_FS_TREE_OBJECTID) ||
		    key.objectid > BTRFS_LAST_FREE_OBJECTID)
			goto skip;

		eb = path->nodes[0];
		slot = path->slots[0];
		item_size = btrfs_item_size_nr(eb, slot);
		if (item_size < sizeof(root_item))
			goto skip;

		read_extent_buffer(eb, &root_item,
				   btrfs_item_ptr_offset(eb, slot),
				   (int)sizeof(root_item));
		if (btrfs_root_refs(&root_item) == 0)
			goto skip;

		if (!btrfs_is_empty_uuid(root_item.uuid) ||
		    !btrfs_is_empty_uuid(root_item.received_uuid)) {
			if (trans)
				goto update_tree;

			btrfs_release_path(path);
			/*
			 * 1 - subvol uuid item
			 * 1 - received_subvol uuid item
			 */
			trans = btrfs_start_transaction(fs_info->uuid_root, 2);
			if (IS_ERR(trans)) {
				ret = PTR_ERR(trans);
				break;
			}
			continue;
		} else {
			goto skip;
		}
update_tree:
		if (!btrfs_is_empty_uuid(root_item.uuid)) {
			ret = btrfs_uuid_tree_add(trans, root_item.uuid,
						  BTRFS_UUID_KEY_SUBVOL,
						  key.objectid);
			if (ret < 0) {
				btrfs_warn(fs_info, "uuid_tree_add failed %d",
					ret);
				break;
			}
		}

		if (!btrfs_is_empty_uuid(root_item.received_uuid)) {
			ret = btrfs_uuid_tree_add(trans,
						  root_item.received_uuid,
						 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
						  key.objectid);
			if (ret < 0) {
				btrfs_warn(fs_info, "uuid_tree_add failed %d",
					ret);
				break;
			}
		}

skip:
		if (trans) {
			ret = btrfs_end_transaction(trans);
			trans = NULL;
			if (ret)
				break;
		}

		btrfs_release_path(path);
		if (key.offset < (u64)-1) {
			key.offset++;
		} else if (key.type < BTRFS_ROOT_ITEM_KEY) {
			key.offset = 0;
			key.type = BTRFS_ROOT_ITEM_KEY;
		} else if (key.objectid < (u64)-1) {
			key.offset = 0;
			key.type = BTRFS_ROOT_ITEM_KEY;
			key.objectid++;
		} else {
			break;
		}
		cond_resched();
	}

out:
	btrfs_free_path(path);
	if (trans && !IS_ERR(trans))
		btrfs_end_transaction(trans);
	if (ret)
		btrfs_warn(fs_info, "btrfs_uuid_scan_kthread failed %d", ret);
	else
		set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags);
	up(&fs_info->uuid_tree_rescan_sem);
	return 0;
}

Project: linux
File: volumes.c

static int btrfs_prepare_sprout(struct btrfs_fs_info *fs_info)
{
	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
	struct btrfs_fs_devices *old_devices;
	struct btrfs_fs_devices *seed_devices;
	struct btrfs_super_block *disk_super = fs_info->super_copy;
	struct btrfs_device *device;
	u64 super_flags;

	lockdep_assert_held(&uuid_mutex);
	if (!fs_devices->seeding)
		return -EINVAL;

	seed_devices = alloc_fs_devices(NULL, NULL);
	if (IS_ERR(seed_devices))
		return PTR_ERR(seed_devices);

	old_devices = clone_fs_devices(fs_devices);
	if (IS_ERR(old_devices)) {
		kfree(seed_devices);
		return PTR_ERR(old_devices);
	}

	list_add(&old_devices->fs_list, &fs_uuids);

	memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
	seed_devices->opened = 1;
	INIT_LIST_HEAD(&seed_devices->devices);
	INIT_LIST_HEAD(&seed_devices->alloc_list);
	mutex_init(&seed_devices->device_list_mutex);

	mutex_lock(&fs_devices->device_list_mutex);
	list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
			      synchronize_rcu);
	list_for_each_entry(device, &seed_devices->devices, dev_list)
		device->fs_devices = seed_devices;

	mutex_lock(&fs_info->chunk_mutex);
	list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
	mutex_unlock(&fs_info->chunk_mutex);

	fs_devices->seeding = 0;
	fs_devices->num_devices = 0;
	fs_devices->open_devices = 0;
	fs_devices->missing_devices = 0;
	fs_devices->rotating = 0;
	fs_devices->seed = seed_devices;

	generate_random_uuid(fs_devices->fsid);
	memcpy(fs_devices->metadata_uuid, fs_devices->fsid, BTRFS_FSID_SIZE);
	memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
	mutex_unlock(&fs_devices->device_list_mutex);

	super_flags = btrfs_super_flags(disk_super) &
		      ~BTRFS_SUPER_FLAG_SEEDING;
	btrfs_set_super_flags(disk_super, super_flags);

	return 0;
}

Project: linux
File: volumes.c

int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
{
	struct btrfs_fs_info *fs_info = device->fs_info;
	struct btrfs_root *root = fs_info->dev_root;
	struct btrfs_trans_handle *trans;
	struct btrfs_dev_extent *dev_extent = NULL;
	struct btrfs_path *path;
	u64 length;
	u64 chunk_offset;
	int ret;
	int slot;
	int failed = 0;
	bool retried = false;
	bool checked_pending_chunks = false;
	struct extent_buffer *l;
	struct btrfs_key key;
	struct btrfs_super_block *super_copy = fs_info->super_copy;
	u64 old_total = btrfs_super_total_bytes(super_copy);
	u64 old_size = btrfs_device_get_total_bytes(device);
	u64 diff;

	new_size = round_down(new_size, fs_info->sectorsize);
	diff = round_down(old_size - new_size, fs_info->sectorsize);

	if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
		return -EINVAL;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	path->reada = READA_BACK;

	mutex_lock(&fs_info->chunk_mutex);

	btrfs_device_set_total_bytes(device, new_size);
	if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
		device->fs_devices->total_rw_bytes -= diff;
		atomic64_sub(diff, &fs_info->free_chunk_space);
	}
	mutex_unlock(&fs_info->chunk_mutex);

again:
	key.objectid = device->devid;
	key.offset = (u64)-1;
	key.type = BTRFS_DEV_EXTENT_KEY;

	do {
		mutex_lock(&fs_info->delete_unused_bgs_mutex);
		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		if (ret < 0) {
			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
			goto done;
		}

		ret = btrfs_previous_item(root, path, 0, key.type);
		if (ret)
			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
		if (ret < 0)
			goto done;
		if (ret) {
			ret = 0;
			btrfs_release_path(path);
			break;
		}

		l = path->nodes[0];
		slot = path->slots[0];
		btrfs_item_key_to_cpu(l, &key, path->slots[0]);

		if (key.objectid != device->devid) {
			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
			btrfs_release_path(path);
			break;
		}

		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
		length = btrfs_dev_extent_length(l, dev_extent);

		if (key.offset + length <= new_size) {
			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
			btrfs_release_path(path);
			break;
		}

		chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
		btrfs_release_path(path);

		/*
		 * We may be relocating the only data chunk we have,
		 * which could potentially end up with losing data's
		 * raid profile, so lets allocate an empty one in
		 * advance.
		 */
		ret = btrfs_may_alloc_data_chunk(fs_info, chunk_offset);
		if (ret < 0) {
			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
			goto done;
		}

		ret = btrfs_relocate_chunk(fs_info, chunk_offset);
		mutex_unlock(&fs_info->delete_unused_bgs_mutex);
		if (ret == -ENOSPC) {
			failed++;
		} else if (ret) {
			if (ret == -ETXTBSY) {
				btrfs_warn(fs_info,
		   "could not shrink block group %llu due to active swapfile",
					   chunk_offset);
			}
			goto done;
		}
	} while (key.offset-- > 0);

	if (failed && !retried) {
		failed = 0;
		retried = true;
		goto again;
	} else if (failed && retried) {
		ret = -ENOSPC;
		goto done;
	}

	/* Shrinking succeeded, else we would be at "done". */
	trans = btrfs_start_transaction(root, 0);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		goto done;
	}

	mutex_lock(&fs_info->chunk_mutex);

	/*
	 * We checked in the above loop all device extents that were already in
	 * the device tree. However before we have updated the device's
	 * total_bytes to the new size, we might have had chunk allocations that
	 * have not complete yet (new block groups attached to transaction
	 * handles), and therefore their device extents were not yet in the
	 * device tree and we missed them in the loop above. So if we have any
	 * pending chunk using a device extent that overlaps the device range
	 * that we can not use anymore, commit the current transaction and
	 * repeat the search on the device tree - this way we guarantee we will
	 * not have chunks using device extents that end beyond 'new_size'.
	 */
	if (!checked_pending_chunks) {
		u64 start = new_size;
		u64 len = old_size - new_size;

		if (contains_pending_extent(trans->transaction, device,
					    &start, len)) {
			mutex_unlock(&fs_info->chunk_mutex);
			checked_pending_chunks = true;
			failed = 0;
			retried = false;
			ret = btrfs_commit_transaction(trans);
			if (ret)
				goto done;
			goto again;
		}
	}

	btrfs_device_set_disk_total_bytes(device, new_size);
	if (list_empty(&device->resized_list))
		list_add_tail(&device->resized_list,
			      &fs_info->fs_devices->resized_devices);

	WARN_ON(diff > old_total);
	btrfs_set_super_total_bytes(super_copy,
			round_down(old_total - diff, fs_info->sectorsize));
	mutex_unlock(&fs_info->chunk_mutex);

	/* Now btrfs_update_device() will change the on-disk size. */
	ret = btrfs_update_device(trans, device);
	if (ret < 0) {
		btrfs_abort_transaction(trans, ret);
		btrfs_end_transaction(trans);
	} else {
		ret = btrfs_commit_transaction(trans);
	}
done:
	btrfs_free_path(path);
	if (ret) {
		mutex_lock(&fs_info->chunk_mutex);
		btrfs_device_set_total_bytes(device, old_size);
		if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state))
			device->fs_devices->total_rw_bytes += diff;
		atomic64_add(diff, &fs_info->free_chunk_space);
		mutex_unlock(&fs_info->chunk_mutex);
	}
	return ret;
}

Project: linux
File: volumes.c

static struct btrfs_fs_devices *open_seed_devices(struct btrfs_fs_info *fs_info,
						  u8 *fsid)
{
	struct btrfs_fs_devices *fs_devices;
	int ret;

	lockdep_assert_held(&uuid_mutex);
	ASSERT(fsid);

	fs_devices = fs_info->fs_devices->seed;
	while (fs_devices) {
		if (!memcmp(fs_devices->fsid, fsid, BTRFS_FSID_SIZE))
			return fs_devices;

		fs_devices = fs_devices->seed;
	}

	fs_devices = find_fsid(fsid, NULL);
	if (!fs_devices) {
		if (!btrfs_test_opt(fs_info, DEGRADED))
			return ERR_PTR(-ENOENT);

		fs_devices = alloc_fs_devices(fsid, NULL);
		if (IS_ERR(fs_devices))
			return fs_devices;

		fs_devices->seeding = 1;
		fs_devices->opened = 1;
		return fs_devices;
	}

	fs_devices = clone_fs_devices(fs_devices);
	if (IS_ERR(fs_devices))
		return fs_devices;

	ret = open_fs_devices(fs_devices, FMODE_READ, fs_info->bdev_holder);
	if (ret) {
		free_fs_devices(fs_devices);
		fs_devices = ERR_PTR(ret);
		goto out;
	}

	if (!fs_devices->seeding) {
		close_fs_devices(fs_devices);
		free_fs_devices(fs_devices);
		fs_devices = ERR_PTR(-EINVAL);
		goto out;
	}

	fs_devices->seed = fs_info->fs_devices->seed;
	fs_info->fs_devices->seed = fs_devices;
out:
	return fs_devices;
}

Project: linux
File: volumes.c

int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *tree_root = fs_info->tree_root;
	struct btrfs_root *uuid_root;
	struct task_struct *task;
	int ret;

	/*
	 * 1 - root node
	 * 1 - root item
	 */
	trans = btrfs_start_transaction(tree_root, 2);
	if (IS_ERR(trans))
		return PTR_ERR(trans);

	uuid_root = btrfs_create_tree(trans, fs_info,
				      BTRFS_UUID_TREE_OBJECTID);
	if (IS_ERR(uuid_root)) {
		ret = PTR_ERR(uuid_root);
		btrfs_abort_transaction(trans, ret);
		btrfs_end_transaction(trans);
		return ret;
	}

	fs_info->uuid_root = uuid_root;

	ret = btrfs_commit_transaction(trans);
	if (ret)
		return ret;

	down(&fs_info->uuid_tree_rescan_sem);
	task = kthread_run(btrfs_uuid_scan_kthread, fs_info, "btrfs-uuid");
	if (IS_ERR(task)) {
		/* fs_info->update_uuid_tree_gen remains 0 in all error case */
		btrfs_warn(fs_info, "failed to start uuid_scan task");
		up(&fs_info->uuid_tree_rescan_sem);
		return PTR_ERR(task);
	}

	return 0;
}

Project: linux
File: ioctl.c

static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
{
	struct inode *inode = file_inode(file);
	struct btrfs_inode *binode = BTRFS_I(inode);
	struct btrfs_root *root = binode->root;
	struct btrfs_trans_handle *trans;
	struct fsxattr fa;
	unsigned old_flags;
	unsigned old_i_flags;
	int ret = 0;

	if (!inode_owner_or_capable(inode))
		return -EPERM;

	if (btrfs_root_readonly(root))
		return -EROFS;

	memset(&fa, 0, sizeof(fa));
	if (copy_from_user(&fa, arg, sizeof(fa)))
		return -EFAULT;

	ret = check_xflags(fa.fsx_xflags);
	if (ret)
		return ret;

	if (fa.fsx_extsize != 0 || fa.fsx_projid != 0 || fa.fsx_cowextsize != 0)
		return -EOPNOTSUPP;

	ret = mnt_want_write_file(file);
	if (ret)
		return ret;

	inode_lock(inode);

	old_flags = binode->flags;
	old_i_flags = inode->i_flags;

	/* We need the capabilities to change append-only or immutable inode */
	if (((old_flags & (BTRFS_INODE_APPEND | BTRFS_INODE_IMMUTABLE)) ||
	     (fa.fsx_xflags & (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE))) &&
	    !capable(CAP_LINUX_IMMUTABLE)) {
		ret = -EPERM;
		goto out_unlock;
	}

	if (fa.fsx_xflags & FS_XFLAG_SYNC)
		binode->flags |= BTRFS_INODE_SYNC;
	else
		binode->flags &= ~BTRFS_INODE_SYNC;
	if (fa.fsx_xflags & FS_XFLAG_IMMUTABLE)
		binode->flags |= BTRFS_INODE_IMMUTABLE;
	else
		binode->flags &= ~BTRFS_INODE_IMMUTABLE;
	if (fa.fsx_xflags & FS_XFLAG_APPEND)
		binode->flags |= BTRFS_INODE_APPEND;
	else
		binode->flags &= ~BTRFS_INODE_APPEND;
	if (fa.fsx_xflags & FS_XFLAG_NODUMP)
		binode->flags |= BTRFS_INODE_NODUMP;
	else
		binode->flags &= ~BTRFS_INODE_NODUMP;
	if (fa.fsx_xflags & FS_XFLAG_NOATIME)
		binode->flags |= BTRFS_INODE_NOATIME;
	else
		binode->flags &= ~BTRFS_INODE_NOATIME;

	/* 1 item for the inode */
	trans = btrfs_start_transaction(root, 1);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		goto out_unlock;
	}

	btrfs_sync_inode_flags_to_i_flags(inode);
	inode_inc_iversion(inode);
	inode->i_ctime = current_time(inode);
	ret = btrfs_update_inode(trans, root, inode);

	btrfs_end_transaction(trans);

out_unlock:
	if (ret) {
		binode->flags = old_flags;
		inode->i_flags = old_i_flags;
	}

	inode_unlock(inode);
	mnt_drop_write_file(file);

	return ret;
}

Project: linux
File: scrub.c

static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
{
	atomic_dec(&sctx->bios_in_flight);
	wake_up(&sctx->list_wait);
	scrub_put_ctx(sctx);
}

Project: linux
File: volumes.c

static int verify_chunk_dev_extent_mapping(struct btrfs_fs_info *fs_info)
{
	struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
	struct extent_map *em;
	struct rb_node *node;
	int ret = 0;

	read_lock(&em_tree->lock);
	for (node = rb_first_cached(&em_tree->map); node; node = rb_next(node)) {
		em = rb_entry(node, struct extent_map, rb_node);
		if (em->map_lookup->num_stripes !=
		    em->map_lookup->verified_stripes) {
			btrfs_err(fs_info,
			"chunk %llu has missing dev extent, have %d expect %d",
				  em->start, em->map_lookup->verified_stripes,
				  em->map_lookup->num_stripes);
			ret = -EUCLEAN;
			goto out;
		}
	}
out:
	read_unlock(&em_tree->lock);
	return ret;
}

Project: linux
File: volumes.c

static inline int parity_smaller(u64 a, u64 b)
{
	return a > b;
}

Project: linux
File: ioctl.c

static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
{
	struct inode *inode = file_inode(file);
	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
	struct btrfs_device *device;
	struct request_queue *q;
	struct fstrim_range range;
	u64 minlen = ULLONG_MAX;
	u64 num_devices = 0;
	int ret;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	rcu_read_lock();
	list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
				dev_list) {
		if (!device->bdev)
			continue;
		q = bdev_get_queue(device->bdev);
		if (blk_queue_discard(q)) {
			num_devices++;
			minlen = min_t(u64, q->limits.discard_granularity,
				     minlen);
		}
	}
	rcu_read_unlock();

	if (!num_devices)
		return -EOPNOTSUPP;
	if (copy_from_user(&range, arg, sizeof(range)))
		return -EFAULT;

	/*
	 * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
	 * block group is in the logical address space, which can be any
	 * sectorsize aligned bytenr in  the range [0, U64_MAX].
	 */
	if (range.len < fs_info->sb->s_blocksize)
		return -EINVAL;

	range.minlen = max(range.minlen, minlen);
	ret = btrfs_trim_fs(fs_info, &range);
	if (ret < 0)
		return ret;

	if (copy_to_user(arg, &range, sizeof(range)))
		return -EFAULT;

	return 0;
}

Project: linux
File: ioctl.c

static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
					      void __user *arg)
{
	struct inode *inode = file_inode(file);
	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;
	u64 root_flags;
	u64 flags;
	int ret = 0;

	if (!inode_owner_or_capable(inode))
		return -EPERM;

	ret = mnt_want_write_file(file);
	if (ret)
		goto out;

	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
		ret = -EINVAL;
		goto out_drop_write;
	}

	if (copy_from_user(&flags, arg, sizeof(flags))) {
		ret = -EFAULT;
		goto out_drop_write;
	}

	if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
		ret = -EINVAL;
		goto out_drop_write;
	}

	if (flags & ~BTRFS_SUBVOL_RDONLY) {
		ret = -EOPNOTSUPP;
		goto out_drop_write;
	}

	down_write(&fs_info->subvol_sem);

	/* nothing to do */
	if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
		goto out_drop_sem;

	root_flags = btrfs_root_flags(&root->root_item);
	if (flags & BTRFS_SUBVOL_RDONLY) {
		btrfs_set_root_flags(&root->root_item,
				     root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
	} else {
		/*
		 * Block RO -> RW transition if this subvolume is involved in
		 * send
		 */
		spin_lock(&root->root_item_lock);
		if (root->send_in_progress == 0) {
			btrfs_set_root_flags(&root->root_item,
				     root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
			spin_unlock(&root->root_item_lock);
		} else {
			spin_unlock(&root->root_item_lock);
			btrfs_warn(fs_info,
				   "Attempt to set subvolume %llu read-write during send",
				   root->root_key.objectid);
			ret = -EPERM;
			goto out_drop_sem;
		}
	}

	trans = btrfs_start_transaction(root, 1);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		goto out_reset;
	}

	ret = btrfs_update_root(trans, fs_info->tree_root,
				&root->root_key, &root->root_item);
	if (ret < 0) {
		btrfs_end_transaction(trans);
		goto out_reset;
	}

	ret = btrfs_commit_transaction(trans);

out_reset:
	if (ret)
		btrfs_set_root_flags(&root->root_item, root_flags);
out_drop_sem:
	up_write(&fs_info->subvol_sem);
out_drop_write:
	mnt_drop_write_file(file);
out:
	return ret;
}