Commit message: ext4: always verify the magic number in xattr blocks

If there an inode points to a block which is also some other type of
metadata block (such as a block allocation bitmap), the
buffer_verified flag can be set when it was validated as that other
metadata block type; however, it would make a really terrible external
attribute block.  The reason why we use the verified flag is to avoid
constantly reverifying the block.  However, it doesn't take much
overhead to make sure the magic number of the xattr block is correct,
and this will avoid potential crashes.

This addresses CVE-2018-10879.

https://bugzilla.kernel.org/show_bug.cgi?id=200001

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Cc: stable@kernel.org
CVE: CVE-2018-10879
CWE: CWE-416
Vulnerability description: A flaw was found in the Linux kernel's ext4 filesystem. A local user can cause a use-after-free in ext4_xattr_set_entry function and a denial of service or unspecified other impact may occur by renaming a file in a crafted ext4 filesystem image.

Project: linux
File: xattr.c

int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
			   bool is_create, int *credits)
{
	struct buffer_head *bh;
	int err;

	*credits = 0;

	if (!EXT4_SB(inode->i_sb)->s_journal)
		return 0;

	down_read(&EXT4_I(inode)->xattr_sem);

	bh = ext4_xattr_get_block(inode);
	if (IS_ERR(bh)) {
		err = PTR_ERR(bh);
	} else {
		*credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
						    value_len, is_create);
		brelse(bh);
		err = 0;
	}

	up_read(&EXT4_I(inode)->xattr_sem);
	return err;
}

Project: linux
File: xattr.c

ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent,
			     struct buffer_head *bh,
			     struct ext4_xattr_entry *first, bool block_csum,
			     struct ext4_xattr_inode_array **ea_inode_array,
			     int extra_credits, bool skip_quota)
{
	struct inode *ea_inode;
	struct ext4_xattr_entry *entry;
	bool dirty = false;
	unsigned int ea_ino;
	int err;
	int credits;

	/* One credit for dec ref on ea_inode, one for orphan list addition, */
	credits = 2 + extra_credits;

	for (entry = first; !IS_LAST_ENTRY(entry);
	     entry = EXT4_XATTR_NEXT(entry)) {
		if (!entry->e_value_inum)
			continue;
		ea_ino = le32_to_cpu(entry->e_value_inum);
		err = ext4_xattr_inode_iget(parent, ea_ino,
					    le32_to_cpu(entry->e_hash),
					    &ea_inode);
		if (err)
			continue;

		err = ext4_expand_inode_array(ea_inode_array, ea_inode);
		if (err) {
			ext4_warning_inode(ea_inode,
					   "Expand inode array err=%d", err);
			iput(ea_inode);
			continue;
		}

		err = ext4_xattr_ensure_credits(handle, parent, credits, bh,
						dirty, block_csum);
		if (err) {
			ext4_warning_inode(ea_inode, "Ensure credits err=%d",
					   err);
			continue;
		}

		err = ext4_xattr_inode_dec_ref(handle, ea_inode);
		if (err) {
			ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d",
					   err);
			continue;
		}

		if (!skip_quota)
			ext4_xattr_inode_free_quota(parent, ea_inode,
					      le32_to_cpu(entry->e_value_size));

		/*
		 * Forget about ea_inode within the same transaction that
		 * decrements the ref count. This avoids duplicate decrements in
		 * case the rest of the work spills over to subsequent
		 * transactions.
		 */
		entry->e_value_inum = 0;
		entry->e_value_size = 0;

		dirty = true;
	}

	if (dirty) {
		/*
		 * Note that we are deliberately skipping csum calculation for
		 * the final update because we do not expect any journal
		 * restarts until xattr block is freed.
		 */

		err = ext4_handle_dirty_metadata(handle, NULL, bh);
		if (err)
			ext4_warning_inode(parent,
					   "handle dirty metadata err=%d", err);
	}
}

Project: linux
File: xattr.c

static struct buffer_head *ext4_xattr_get_block(struct inode *inode)
{
	struct buffer_head *bh;
	int error;

	if (!EXT4_I(inode)->i_file_acl)
		return NULL;
	bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
	if (!bh)
		return ERR_PTR(-EIO);
	error = ext4_xattr_check_block(inode, bh);
	if (error)
		return ERR_PTR(error);
	return bh;
}

Project: linux
File: xattr.c

static inline size_t round_up_cluster(struct inode *inode, size_t length)
{
	struct super_block *sb = inode->i_sb;
	size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits +
				    inode->i_blkbits);
	size_t mask = ~(cluster_size - 1);

	return (length + cluster_size - 1) & mask;
}

Project: linux
File: xattr.c

ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
{
	struct inode *inode = d_inode(dentry);
	struct ext4_xattr_ibody_header *header;
	struct ext4_inode *raw_inode;
	struct ext4_iloc iloc;
	void *end;
	int error;

	if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
		return 0;
	error = ext4_get_inode_loc(inode, &iloc);
	if (error)
		return error;
	raw_inode = ext4_raw_inode(&iloc);
	header = IHDR(inode, raw_inode);
	end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
	error = xattr_check_inode(inode, header, end);
	if (error)
		goto cleanup;
	error = ext4_xattr_list_entries(dentry, IFIRST(header),
					buffer, buffer_size);

cleanup:
	brelse(iloc.bh);
	return error;
}

Project: linux
File: xattr.c

static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len)
{
	int err;

	err = dquot_alloc_inode(inode);
	if (err)
		return err;
	err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len));
	if (err)
		dquot_free_inode(inode);
	return err;
}

Project: linux
File: xattr.c

ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
			char *buffer, size_t buffer_size)
{
	size_t rest = buffer_size;

	for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
		const struct xattr_handler *handler =
			ext4_xattr_handler(entry->e_name_index);

		if (handler && (!handler->list || handler->list(dentry))) {
			const char *prefix = handler->prefix ?: handler->name;
			size_t prefix_len = strlen(prefix);
			size_t size = prefix_len + entry->e_name_len + 1;

			if (buffer) {
				if (size > rest)
					return -ERANGE;
				memcpy(buffer, prefix, prefix_len);
				buffer += prefix_len;
				memcpy(buffer, entry->e_name, entry->e_name_len);
				buffer += entry->e_name_len;
				*buffer++ = 0;
			}
			rest -= size;
		}
	}
	return buffer_size - rest;  /* total size */
}

Project: linux
File: xattr.c

int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode,
			     struct buffer_head *block_bh, size_t value_len,
			     bool is_create)
{
	int credits;
	int blocks;

	/*
	 * 1) Owner inode update
	 * 2) Ref count update on old xattr block
	 * 3) new xattr block
	 * 4) block bitmap update for new xattr block
	 * 5) group descriptor for new xattr block
	 * 6) block bitmap update for old xattr block
	 * 7) group descriptor for old block
	 *
	 * 6 & 7 can happen if we have two racing threads T_a and T_b
	 * which are each trying to set an xattr on inodes I_a and I_b
	 * which were both initially sharing an xattr block.
	 */
	credits = 7;

	/* Quota updates. */
	credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb);

	/*
	 * In case of inline data, we may push out the data to a block,
	 * so we need to reserve credits for this eventuality
	 */
	if (inode && ext4_has_inline_data(inode))
		credits += ext4_writepage_trans_blocks(inode) + 1;

	/* We are done if ea_inode feature is not enabled. */
	if (!ext4_has_feature_ea_inode(sb))
		return credits;

	/* New ea_inode, inode map, block bitmap, group descriptor. */
	credits += 4;

	/* Data blocks. */
	blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits;

	/* Indirection block or one level of extent tree. */
	blocks += 1;

	/* Block bitmap and group descriptor updates for each block. */
	credits += blocks * 2;

	/* Blocks themselves. */
	credits += blocks;

	if (!is_create) {
		/* Dereference ea_inode holding old xattr value.
		 * Old ea_inode, inode map, block bitmap, group descriptor.
		 */
		credits += 4;

		/* Data blocks for old ea_inode. */
		blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits;

		/* Indirection block or one level of extent tree for old
		 * ea_inode.
		 */
		blocks += 1;

		/* Block bitmap and group descriptor updates for each block. */
		credits += blocks * 2;
	}

	/* We may need to clone the existing xattr block in which case we need
	 * to increment ref counts for existing ea_inodes referenced by it.
	 */
	if (block_bh) {
		struct ext4_xattr_entry *entry = BFIRST(block_bh);

		for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry))
			if (entry->e_value_inum)
				/* Ref count update on ea_inode. */
				credits += 1;
	}
	return credits;
}

Project: linux
File: xattr.c

void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array)
{
	int idx;

	if (ea_inode_array == NULL)
		return;

	for (idx = 0; idx < ea_inode_array->count; ++idx)
		iput(ea_inode_array->inodes[idx]);
	kfree(ea_inode_array);
}

Project: linux
File: xattr.c

int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
			  struct ext4_xattr_ibody_find *is)
{
	struct ext4_xattr_ibody_header *header;
	struct ext4_inode *raw_inode;
	int error;

	if (EXT4_I(inode)->i_extra_isize == 0)
		return 0;
	raw_inode = ext4_raw_inode(&is->iloc);
	header = IHDR(inode, raw_inode);
	is->s.base = is->s.first = IFIRST(header);
	is->s.here = is->s.first;
	is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
	if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
		error = xattr_check_inode(inode, header, is->s.end);
		if (error)
			return error;
		/* Find the named attribute. */
		error = xattr_find_entry(inode, &is->s.here, is->s.end,
					 i->name_index, i->name, 0);
		if (error && error != -ENODATA)
			return error;
		is->s.not_found = error;
	}
	return 0;
}

Project: linux
File: xattr.c

ext4_xattr_set(struct inode *inode, int name_index, const char *name,
	       const void *value, size_t value_len, int flags)
{
	handle_t *handle;
	struct super_block *sb = inode->i_sb;
	int error, retries = 0;
	int credits;

	error = dquot_initialize(inode);
	if (error)
		return error;

retry:
	error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE,
				       &credits);
	if (error)
		return error;

	handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
	if (IS_ERR(handle)) {
		error = PTR_ERR(handle);
	} else {
		int error2;

		error = ext4_xattr_set_handle(handle, inode, name_index, name,
					      value, value_len, flags);
		error2 = ext4_journal_stop(handle);
		if (error == -ENOSPC &&
		    ext4_should_retry_alloc(sb, &retries))
			goto retry;
		if (error == 0)
			error = error2;
	}

	return error;
}

Project: linux
File: xattr.c

ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size)
{
	return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size);
}

Project: linux
File: xattr.c

static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode,
				       int ref_change)
{
	struct mb_cache *ea_inode_cache = EA_INODE_CACHE(ea_inode);
	struct ext4_iloc iloc;
	s64 ref_count;
	u32 hash;
	int ret;

	inode_lock(ea_inode);

	ret = ext4_reserve_inode_write(handle, ea_inode, &iloc);
	if (ret) {
		iloc.bh = NULL;
		goto out;
	}

	ref_count = ext4_xattr_inode_get_ref(ea_inode);
	ref_count += ref_change;
	ext4_xattr_inode_set_ref(ea_inode, ref_count);

	if (ref_change > 0) {
		WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld",
			  ea_inode->i_ino, ref_count);

		if (ref_count == 1) {
			WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u",
				  ea_inode->i_ino, ea_inode->i_nlink);

			set_nlink(ea_inode, 1);
			ext4_orphan_del(handle, ea_inode);

			if (ea_inode_cache) {
				hash = ext4_xattr_inode_get_hash(ea_inode);
				mb_cache_entry_create(ea_inode_cache,
						      GFP_NOFS, hash,
						      ea_inode->i_ino,
						      true /* reusable */);
			}
		}
	} else {
		WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld",
			  ea_inode->i_ino, ref_count);

		if (ref_count == 0) {
			WARN_ONCE(ea_inode->i_nlink != 1,
				  "EA inode %lu i_nlink=%u",
				  ea_inode->i_ino, ea_inode->i_nlink);

			clear_nlink(ea_inode);
			ext4_orphan_add(handle, ea_inode);

			if (ea_inode_cache) {
				hash = ext4_xattr_inode_get_hash(ea_inode);
				mb_cache_entry_delete(ea_inode_cache, hash,
						      ea_inode->i_ino);
			}
		}
	}

	ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc);
	iloc.bh = NULL;
	if (ret)
		ext4_warning_inode(ea_inode,
				   "ext4_mark_iloc_dirty() failed ret=%d", ret);
out:
	brelse(iloc.bh);
	inode_unlock(ea_inode);
	return ret;
}

Project: linux
File: xattr.c

__xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header,
			 void *end, const char *function, unsigned int line)
{
	int error = -EFSCORRUPTED;

	if (end - (void *)header < sizeof(*header) + sizeof(u32) ||
	    (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)))
		goto errout;
	error = ext4_xattr_check_entries(IFIRST(header), end, IFIRST(header));
errout:
	if (error)
		__ext4_error_inode(inode, function, line, 0,
				   "corrupted in-inode xattr");
	return error;
}

Project: linux
File: xattr.c

static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
				struct ext4_xattr_search *s,
				handle_t *handle, struct inode *inode,
				bool is_block)
{
	struct ext4_xattr_entry *last, *next;
	struct ext4_xattr_entry *here = s->here;
	size_t min_offs = s->end - s->base, name_len = strlen(i->name);
	int in_inode = i->in_inode;
	struct inode *old_ea_inode = NULL;
	struct inode *new_ea_inode = NULL;
	size_t old_size, new_size;
	int ret;

	/* Space used by old and new values. */
	old_size = (!s->not_found && !here->e_value_inum) ?
			EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0;
	new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0;

	/*
	 * Optimization for the simple case when old and new values have the
	 * same padded sizes. Not applicable if external inodes are involved.
	 */
	if (new_size && new_size == old_size) {
		size_t offs = le16_to_cpu(here->e_value_offs);
		void *val = s->base + offs;

		here->e_value_size = cpu_to_le32(i->value_len);
		if (i->value == EXT4_ZERO_XATTR_VALUE) {
			memset(val, 0, new_size);
		} else {
			memcpy(val, i->value, i->value_len);
			/* Clear padding bytes. */
			memset(val + i->value_len, 0, new_size - i->value_len);
		}
		goto update_hash;
	}

	/* Compute min_offs and last. */
	last = s->first;
	for (; !IS_LAST_ENTRY(last); last = next) {
		next = EXT4_XATTR_NEXT(last);
		if ((void *)next >= s->end) {
			EXT4_ERROR_INODE(inode, "corrupted xattr entries");
			ret = -EFSCORRUPTED;
			goto out;
		}
		if (!last->e_value_inum && last->e_value_size) {
			size_t offs = le16_to_cpu(last->e_value_offs);
			if (offs < min_offs)
				min_offs = offs;
		}
	}

	/* Check whether we have enough space. */
	if (i->value) {
		size_t free;

		free = min_offs - ((void *)last - s->base) - sizeof(__u32);
		if (!s->not_found)
			free += EXT4_XATTR_LEN(name_len) + old_size;

		if (free < EXT4_XATTR_LEN(name_len) + new_size) {
			ret = -ENOSPC;
			goto out;
		}

		/*
		 * If storing the value in an external inode is an option,
		 * reserve space for xattr entries/names in the external
		 * attribute block so that a long value does not occupy the
		 * whole space and prevent futher entries being added.
		 */
		if (ext4_has_feature_ea_inode(inode->i_sb) &&
		    new_size && is_block &&
		    (min_offs + old_size - new_size) <
					EXT4_XATTR_BLOCK_RESERVE(inode)) {
			ret = -ENOSPC;
			goto out;
		}
	}

	/*
	 * Getting access to old and new ea inodes is subject to failures.
	 * Finish that work before doing any modifications to the xattr data.
	 */
	if (!s->not_found && here->e_value_inum) {
		ret = ext4_xattr_inode_iget(inode,
					    le32_to_cpu(here->e_value_inum),
					    le32_to_cpu(here->e_hash),
					    &old_ea_inode);
		if (ret) {
			old_ea_inode = NULL;
			goto out;
		}
	}
	if (i->value && in_inode) {
		WARN_ON_ONCE(!i->value_len);

		ret = ext4_xattr_inode_alloc_quota(inode, i->value_len);
		if (ret)
			goto out;

		ret = ext4_xattr_inode_lookup_create(handle, inode, i->value,
						     i->value_len,
						     &new_ea_inode);
		if (ret) {
			new_ea_inode = NULL;
			ext4_xattr_inode_free_quota(inode, NULL, i->value_len);
			goto out;
		}
	}

	if (old_ea_inode) {
		/* We are ready to release ref count on the old_ea_inode. */
		ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode);
		if (ret) {
			/* Release newly required ref count on new_ea_inode. */
			if (new_ea_inode) {
				int err;

				err = ext4_xattr_inode_dec_ref(handle,
							       new_ea_inode);
				if (err)
					ext4_warning_inode(new_ea_inode,
						  "dec ref new_ea_inode err=%d",
						  err);
				ext4_xattr_inode_free_quota(inode, new_ea_inode,
							    i->value_len);
			}
			goto out;
		}

		ext4_xattr_inode_free_quota(inode, old_ea_inode,
					    le32_to_cpu(here->e_value_size));
	}

	/* No failures allowed past this point. */

	if (!s->not_found && here->e_value_size && here->e_value_offs) {
		/* Remove the old value. */
		void *first_val = s->base + min_offs;
		size_t offs = le16_to_cpu(here->e_value_offs);
		void *val = s->base + offs;

		memmove(first_val + old_size, first_val, val - first_val);
		memset(first_val, 0, old_size);
		min_offs += old_size;

		/* Adjust all value offsets. */
		last = s->first;
		while (!IS_LAST_ENTRY(last)) {
			size_t o = le16_to_cpu(last->e_value_offs);

			if (!last->e_value_inum &&
			    last->e_value_size && o < offs)
				last->e_value_offs = cpu_to_le16(o + old_size);
			last = EXT4_XATTR_NEXT(last);
		}
	}

	if (!i->value) {
		/* Remove old name. */
		size_t size = EXT4_XATTR_LEN(name_len);

		last = ENTRY((void *)last - size);
		memmove(here, (void *)here + size,
			(void *)last - (void *)here + sizeof(__u32));
		memset(last, 0, size);
	} else if (s->not_found) {
		/* Insert new name. */
		size_t size = EXT4_XATTR_LEN(name_len);
		size_t rest = (void *)last - (void *)here + sizeof(__u32);

		memmove((void *)here + size, here, rest);
		memset(here, 0, size);
		here->e_name_index = i->name_index;
		here->e_name_len = name_len;
		memcpy(here->e_name, i->name, name_len);
	} else {
		/* This is an update, reset value info. */
		here->e_value_inum = 0;
		here->e_value_offs = 0;
		here->e_value_size = 0;
	}

	if (i->value) {
		/* Insert new value. */
		if (in_inode) {
			here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino);
		} else if (i->value_len) {
			void *val = s->base + min_offs - new_size;

			here->e_value_offs = cpu_to_le16(min_offs - new_size);
			if (i->value == EXT4_ZERO_XATTR_VALUE) {
				memset(val, 0, new_size);
			} else {
				memcpy(val, i->value, i->value_len);
				/* Clear padding bytes. */
				memset(val + i->value_len, 0,
				       new_size - i->value_len);
			}
		}
		here->e_value_size = cpu_to_le32(i->value_len);
	}

update_hash:
	if (i->value) {
		__le32 hash = 0;

		/* Entry hash calculation. */
		if (in_inode) {
			__le32 crc32c_hash;

			/*
			 * Feed crc32c hash instead of the raw value for entry
			 * hash calculation. This is to avoid walking
			 * potentially long value buffer again.
			 */
			crc32c_hash = cpu_to_le32(
				       ext4_xattr_inode_get_hash(new_ea_inode));
			hash = ext4_xattr_hash_entry(here->e_name,
						     here->e_name_len,
						     &crc32c_hash, 1);
		} else if (is_block) {
			__le32 *value = s->base + le16_to_cpu(
							here->e_value_offs);

			hash = ext4_xattr_hash_entry(here->e_name,
						     here->e_name_len, value,
						     new_size >> 2);
		}
		here->e_hash = hash;
	}

	if (is_block)
		ext4_xattr_rehash((struct ext4_xattr_header *)s->base);

	ret = 0;
out:
	iput(old_ea_inode);
	iput(new_ea_inode);
	return ret;
}

Project: linux
File: xattr.c

ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
		      const char *name, const void *value, size_t value_len,
		      int flags)
{
	struct ext4_xattr_info i = {
		.name_index = name_index,
		.name = name,
		.value = value,
		.value_len = value_len,
		.in_inode = 0,
	};
	struct ext4_xattr_ibody_find is = {
		.s = { .not_found = -ENODATA, },
	};
	struct ext4_xattr_block_find bs = {
		.s = { .not_found = -ENODATA, },
	};
	int no_expand;
	int error;

	if (!name)
		return -EINVAL;
	if (strlen(name) > 255)
		return -ERANGE;

	ext4_write_lock_xattr(inode, &no_expand);

	/* Check journal credits under write lock. */
	if (ext4_handle_valid(handle)) {
		struct buffer_head *bh;
		int credits;

		bh = ext4_xattr_get_block(inode);
		if (IS_ERR(bh)) {
			error = PTR_ERR(bh);
			goto cleanup;
		}

		credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
						   value_len,
						   flags & XATTR_CREATE);
		brelse(bh);

		if (!ext4_handle_has_enough_credits(handle, credits)) {
			error = -ENOSPC;
			goto cleanup;
		}
	}

	error = ext4_reserve_inode_write(handle, inode, &is.iloc);
	if (error)
		goto cleanup;

	if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
		struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
		memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
		ext4_clear_inode_state(inode, EXT4_STATE_NEW);
	}

	error = ext4_xattr_ibody_find(inode, &i, &is);
	if (error)
		goto cleanup;
	if (is.s.not_found)
		error = ext4_xattr_block_find(inode, &i, &bs);
	if (error)
		goto cleanup;
	if (is.s.not_found && bs.s.not_found) {
		error = -ENODATA;
		if (flags & XATTR_REPLACE)
			goto cleanup;
		error = 0;
		if (!value)
			goto cleanup;
	} else {
		error = -EEXIST;
		if (flags & XATTR_CREATE)
			goto cleanup;
	}

	if (!value) {
		if (!is.s.not_found)
			error = ext4_xattr_ibody_set(handle, inode, &i, &is);
		else if (!bs.s.not_found)
			error = ext4_xattr_block_set(handle, inode, &i, &bs);
	} else {
		error = 0;
		/* Xattr value did not change? Save us some work and bail out */
		if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i))
			goto cleanup;
		if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
			goto cleanup;

		if (ext4_has_feature_ea_inode(inode->i_sb) &&
		    (EXT4_XATTR_SIZE(i.value_len) >
			EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize)))
			i.in_inode = 1;
retry_inode:
		error = ext4_xattr_ibody_set(handle, inode, &i, &is);
		if (!error && !bs.s.not_found) {
			i.value = NULL;
			error = ext4_xattr_block_set(handle, inode, &i, &bs);
		} else if (error == -ENOSPC) {
			if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
				error = ext4_xattr_block_find(inode, &i, &bs);
				if (error)
					goto cleanup;
			}
			error = ext4_xattr_block_set(handle, inode, &i, &bs);
			if (!error && !is.s.not_found) {
				i.value = NULL;
				error = ext4_xattr_ibody_set(handle, inode, &i,
							     &is);
			} else if (error == -ENOSPC) {
				/*
				 * Xattr does not fit in the block, store at
				 * external inode if possible.
				 */
				if (ext4_has_feature_ea_inode(inode->i_sb) &&
				    !i.in_inode) {
					i.in_inode = 1;
					goto retry_inode;
				}
			}
		}
	}
	if (!error) {
		ext4_xattr_update_super_block(handle, inode->i_sb);
		inode->i_ctime = current_time(inode);
		if (!value)
			no_expand = 0;
		error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
		/*
		 * The bh is consumed by ext4_mark_iloc_dirty, even with
		 * error != 0.
		 */
		is.iloc.bh = NULL;
		if (IS_SYNC(inode))
			ext4_handle_sync(handle);
	}

cleanup:
	brelse(is.iloc.bh);
	brelse(bs.bh);
	ext4_write_unlock_xattr(inode, &no_expand);
	return error;
}

Project: linux
File: xattr.c

static void ext4_xattr_block_csum_set(struct inode *inode,
				      struct buffer_head *bh)
{
	if (ext4_has_metadata_csum(inode->i_sb))
		BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode,
						bh->b_blocknr, BHDR(bh));
}

Project: linux
File: xattr.c

int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
			       struct ext4_inode *raw_inode, handle_t *handle)
{
	struct ext4_xattr_ibody_header *header;
	struct buffer_head *bh;
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
	static unsigned int mnt_count;
	size_t min_offs;
	size_t ifree, bfree;
	int total_ino;
	void *base, *end;
	int error = 0, tried_min_extra_isize = 0;
	int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize);
	int isize_diff;	/* How much do we need to grow i_extra_isize */

retry:
	isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
	if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
		return 0;

	header = IHDR(inode, raw_inode);

	/*
	 * Check if enough free space is available in the inode to shift the
	 * entries ahead by new_extra_isize.
	 */

	base = IFIRST(header);
	end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
	min_offs = end - base;
	total_ino = sizeof(struct ext4_xattr_ibody_header);

	error = xattr_check_inode(inode, header, end);
	if (error)
		goto cleanup;

	ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino);
	if (ifree >= isize_diff)
		goto shift;

	/*
	 * Enough free space isn't available in the inode, check if
	 * EA block can hold new_extra_isize bytes.
	 */
	if (EXT4_I(inode)->i_file_acl) {
		bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
		error = -EIO;
		if (!bh)
			goto cleanup;
		error = ext4_xattr_check_block(inode, bh);
		if (error)
			goto cleanup;
		base = BHDR(bh);
		end = bh->b_data + bh->b_size;
		min_offs = end - base;
		bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base,
					      NULL);
		brelse(bh);
		if (bfree + ifree < isize_diff) {
			if (!tried_min_extra_isize && s_min_extra_isize) {
				tried_min_extra_isize++;
				new_extra_isize = s_min_extra_isize;
				goto retry;
			}
			error = -ENOSPC;
			goto cleanup;
		}
	} else {
		bfree = inode->i_sb->s_blocksize;
	}

	error = ext4_xattr_make_inode_space(handle, inode, raw_inode,
					    isize_diff, ifree, bfree,
					    &total_ino);
	if (error) {
		if (error == -ENOSPC && !tried_min_extra_isize &&
		    s_min_extra_isize) {
			tried_min_extra_isize++;
			new_extra_isize = s_min_extra_isize;
			goto retry;
		}
		goto cleanup;
	}
shift:
	/* Adjust the offsets and shift the remaining entries ahead */
	ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize
			- new_extra_isize, (void *)raw_inode +
			EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
			(void *)header, total_ino);
	EXT4_I(inode)->i_extra_isize = new_extra_isize;

cleanup:
	if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) {
		ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.",
			     inode->i_ino);
		mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count);
	}
	return error;
}

Project: linux
File: xattr.c

static struct inode *ext4_xattr_inode_create(handle_t *handle,
					     struct inode *inode, u32 hash)
{
	struct inode *ea_inode = NULL;
	uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) };
	int err;

	/*
	 * Let the next inode be the goal, so we try and allocate the EA inode
	 * in the same group, or nearby one.
	 */
	ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
				  S_IFREG | 0600, NULL, inode->i_ino + 1, owner,
				  EXT4_EA_INODE_FL);
	if (!IS_ERR(ea_inode)) {
		ea_inode->i_op = &ext4_file_inode_operations;
		ea_inode->i_fop = &ext4_file_operations;
		ext4_set_aops(ea_inode);
		ext4_xattr_inode_set_class(ea_inode);
		unlock_new_inode(ea_inode);
		ext4_xattr_inode_set_ref(ea_inode, 1);
		ext4_xattr_inode_set_hash(ea_inode, hash);
		err = ext4_mark_inode_dirty(handle, ea_inode);
		if (!err)
			err = ext4_inode_attach_jinode(ea_inode);
		if (err) {
			iput(ea_inode);
			return ERR_PTR(err);
		}

		/*
		 * Xattr inodes are shared therefore quota charging is performed
		 * at a higher level.
		 */
		dquot_free_inode(ea_inode);
		dquot_drop(ea_inode);
		inode_lock(ea_inode);
		ea_inode->i_flags |= S_NOQUOTA;
		inode_unlock(ea_inode);
	}

	return ea_inode;
}

Project: linux
File: xattr.c

ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache,
			      struct buffer_head *bh)
{
	struct ext4_xattr_header *header = BHDR(bh);
	__u32 hash = le32_to_cpu(header->h_hash);
	int reusable = le32_to_cpu(header->h_refcount) <
		       EXT4_XATTR_REFCOUNT_MAX;
	int error;

	if (!ea_block_cache)
		return;
	error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash,
				      bh->b_blocknr, reusable);
	if (error) {
		if (error == -EBUSY)
			ea_bdebug(bh, "already in cache");
	} else
		ea_bdebug(bh, "inserting [%x]", (int)hash);
}

Project: linux
File: xattr.c

static void ext4_xattr_rehash(struct ext4_xattr_header *header)
{
	struct ext4_xattr_entry *here;
	__u32 hash = 0;

	here = ENTRY(header+1);
	while (!IS_LAST_ENTRY(here)) {
		if (!here->e_hash) {
			/* Block is not shared if an entry's hash value == 0 */
			hash = 0;
			break;
		}
		hash = (hash << BLOCK_HASH_SHIFT) ^
		       (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
		       le32_to_cpu(here->e_hash);
		here = EXT4_XATTR_NEXT(here);
	}
	header->h_hash = cpu_to_le32(hash);
}

Project: linux
File: xattr.c

static void ext4_xattr_update_super_block(handle_t *handle,
					  struct super_block *sb)
{
	if (ext4_has_feature_xattr(sb))
		return;

	BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
	if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) {
		ext4_set_feature_xattr(sb);
		ext4_handle_dirty_super(handle, sb);
	}
}

Project: linux
File: xattr.c

static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino,
				 u32 ea_inode_hash, struct inode **ea_inode)
{
	struct inode *inode;
	int err;

	inode = ext4_iget(parent->i_sb, ea_ino);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		ext4_error(parent->i_sb,
			   "error while reading EA inode %lu err=%d", ea_ino,
			   err);
		return err;
	}

	if (is_bad_inode(inode)) {
		ext4_error(parent->i_sb,
			   "error while reading EA inode %lu is_bad_inode",
			   ea_ino);
		err = -EIO;
		goto error;
	}

	if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) {
		ext4_error(parent->i_sb,
			   "EA inode %lu does not have EXT4_EA_INODE_FL flag",
			    ea_ino);
		err = -EINVAL;
		goto error;
	}

	ext4_xattr_inode_set_class(inode);

	/*
	 * Check whether this is an old Lustre-style xattr inode. Lustre
	 * implementation does not have hash validation, rather it has a
	 * backpointer from ea_inode to the parent inode.
	 */
	if (ea_inode_hash != ext4_xattr_inode_get_hash(inode) &&
	    EXT4_XATTR_INODE_GET_PARENT(inode) == parent->i_ino &&
	    inode->i_generation == parent->i_generation) {
		ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE);
		ext4_xattr_inode_set_ref(inode, 1);
	} else {
		inode_lock(inode);
		inode->i_flags |= S_NOQUOTA;
		inode_unlock(inode);
	}

	*ea_inode = inode;
	return 0;
error:
	iput(inode);
	return err;
}

Project: linux
File: xattr.c

static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size)
{
	int blocksize = 1 << ea_inode->i_blkbits;
	int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits;
	int tail_size = (size % blocksize) ?: blocksize;
	struct buffer_head *bhs_inline[8];
	struct buffer_head **bhs = bhs_inline;
	int i, ret;

	if (bh_count > ARRAY_SIZE(bhs_inline)) {
		bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS);
		if (!bhs)
			return -ENOMEM;
	}

	ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count,
			       true /* wait */, bhs);
	if (ret)
		goto free_bhs;

	for (i = 0; i < bh_count; i++) {
		/* There shouldn't be any holes in ea_inode. */
		if (!bhs[i]) {
			ret = -EFSCORRUPTED;
			goto put_bhs;
		}
		memcpy((char *)buf + blocksize * i, bhs[i]->b_data,
		       i < bh_count - 1 ? blocksize : tail_size);
	}
	ret = 0;
put_bhs:
	for (i = 0; i < bh_count; i++)
		brelse(bhs[i]);
free_bhs:
	if (bhs != bhs_inline)
		kfree(bhs);
	return ret;
}

Project: linux
File: xattr.c

static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode)
{
	return ext4_xattr_inode_update_ref(handle, ea_inode, 1);
}

Project: linux
File: xattr.c

ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry,
		     void *buffer, size_t size)
{
	struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
	struct inode *ea_inode;
	int err;

	err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum),
				    le32_to_cpu(entry->e_hash), &ea_inode);
	if (err) {
		ea_inode = NULL;
		goto out;
	}

	if (i_size_read(ea_inode) != size) {
		ext4_warning_inode(ea_inode,
				   "ea_inode file size=%llu entry size=%zu",
				   i_size_read(ea_inode), size);
		err = -EFSCORRUPTED;
		goto out;
	}

	err = ext4_xattr_inode_read(ea_inode, buffer, size);
	if (err)
		goto out;

	if (!ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) {
		err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer,
						     size);
		if (err) {
			ext4_warning_inode(ea_inode,
					   "EA inode hash validation failed");
			goto out;
		}

		if (ea_inode_cache)
			mb_cache_entry_create(ea_inode_cache, GFP_NOFS,
					ext4_xattr_inode_get_hash(ea_inode),
					ea_inode->i_ino, true /* reusable */);
	}
out:
	iput(ea_inode);
	return err;
}

Project: linux
File: xattr.c

ext4_xattr_inode_cache_find(struct inode *inode, const void *value,
			    size_t value_len, u32 hash)
{
	struct inode *ea_inode;
	struct mb_cache_entry *ce;
	struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
	void *ea_data;

	if (!ea_inode_cache)
		return NULL;

	ce = mb_cache_entry_find_first(ea_inode_cache, hash);
	if (!ce)
		return NULL;

	ea_data = ext4_kvmalloc(value_len, GFP_NOFS);
	if (!ea_data) {
		mb_cache_entry_put(ea_inode_cache, ce);
		return NULL;
	}

	while (ce) {
		ea_inode = ext4_iget(inode->i_sb, ce->e_value);
		if (!IS_ERR(ea_inode) &&
		    !is_bad_inode(ea_inode) &&
		    (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) &&
		    i_size_read(ea_inode) == value_len &&
		    !ext4_xattr_inode_read(ea_inode, ea_data, value_len) &&
		    !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data,
						    value_len) &&
		    !memcmp(value, ea_data, value_len)) {
			mb_cache_entry_touch(ea_inode_cache, ce);
			mb_cache_entry_put(ea_inode_cache, ce);
			kvfree(ea_data);
			return ea_inode;
		}

		if (!IS_ERR(ea_inode))
			iput(ea_inode);
		ce = mb_cache_entry_find_next(ea_inode_cache, ce);
	}
	kvfree(ea_data);
	return NULL;
}

Project: linux
File: xattr.c

static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode)
{
	return ((u64)ea_inode->i_ctime.tv_sec << 32) |
		(u32) inode_peek_iversion_raw(ea_inode);
}

Project: linux
File: xattr.c

static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count)
{
	ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32);
	inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff);
}

Project: linux
File: xattr.c

ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
{
	struct inode *inode = d_inode(dentry);
	struct buffer_head *bh = NULL;
	int error;

	ea_idebug(inode, "buffer=%p, buffer_size=%ld",
		  buffer, (long)buffer_size);

	error = 0;
	if (!EXT4_I(inode)->i_file_acl)
		goto cleanup;
	ea_idebug(inode, "reading block %llu",
		  (unsigned long long)EXT4_I(inode)->i_file_acl);
	bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
	error = -EIO;
	if (!bh)
		goto cleanup;
	ea_bdebug(bh, "b_count=%d, refcount=%d",
		atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
	error = ext4_xattr_check_block(inode, bh);
	if (error)
		goto cleanup;
	ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh);
	error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);

cleanup:
	brelse(bh);

	return error;
}

Project: linux
File: xattr.c

void ext4_xattr_destroy_cache(struct mb_cache *cache)
{
	if (cache)
		mb_cache_destroy(cache);
}

Project: linux
File: xattr.c

int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
			    struct ext4_xattr_inode_array **ea_inode_array,
			    int extra_credits)
{
	struct buffer_head *bh = NULL;
	struct ext4_xattr_ibody_header *header;
	struct ext4_iloc iloc = { .bh = NULL };
	struct ext4_xattr_entry *entry;
	struct inode *ea_inode;
	int error;

	error = ext4_xattr_ensure_credits(handle, inode, extra_credits,
					  NULL /* bh */,
					  false /* dirty */,
					  false /* block_csum */);
	if (error) {
		EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error);
		goto cleanup;
	}

	if (ext4_has_feature_ea_inode(inode->i_sb) &&
	    ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {

		error = ext4_get_inode_loc(inode, &iloc);
		if (error) {
			EXT4_ERROR_INODE(inode, "inode loc (error %d)", error);
			goto cleanup;
		}

		error = ext4_journal_get_write_access(handle, iloc.bh);
		if (error) {
			EXT4_ERROR_INODE(inode, "write access (error %d)",
					 error);
			goto cleanup;
		}

		header = IHDR(inode, ext4_raw_inode(&iloc));
		if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC))
			ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh,
						     IFIRST(header),
						     false /* block_csum */,
						     ea_inode_array,
						     extra_credits,
						     false /* skip_quota */);
	}

	if (EXT4_I(inode)->i_file_acl) {
		bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
		if (!bh) {
			EXT4_ERROR_INODE(inode, "block %llu read error",
					 EXT4_I(inode)->i_file_acl);
			error = -EIO;
			goto cleanup;
		}
		error = ext4_xattr_check_block(inode, bh);
		if (error)
			goto cleanup;

		if (ext4_has_feature_ea_inode(inode->i_sb)) {
			for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
			     entry = EXT4_XATTR_NEXT(entry)) {
				if (!entry->e_value_inum)
					continue;
				error = ext4_xattr_inode_iget(inode,
					      le32_to_cpu(entry->e_value_inum),
					      le32_to_cpu(entry->e_hash),
					      &ea_inode);
				if (error)
					continue;
				ext4_xattr_inode_free_quota(inode, ea_inode,
					      le32_to_cpu(entry->e_value_size));
				iput(ea_inode);
			}

		}

		ext4_xattr_release_block(handle, inode, bh, ea_inode_array,
					 extra_credits);
		/*
		 * Update i_file_acl value in the same transaction that releases
		 * block.
		 */
		EXT4_I(inode)->i_file_acl = 0;
		error = ext4_mark_inode_dirty(handle, inode);
		if (error) {
			EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)",
					 error);
			goto cleanup;
		}
	}
	error = 0;
cleanup:
	brelse(iloc.bh);
	brelse(bh);
	return error;
}

Project: linux
File: xattr.c

static int ext4_xattr_value_same(struct ext4_xattr_search *s,
				 struct ext4_xattr_info *i)
{
	void *value;

	/* When e_value_inum is set the value is stored externally. */
	if (s->here->e_value_inum)
		return 0;
	if (le32_to_cpu(s->here->e_value_size) != i->value_len)
		return 0;
	value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);
	return !memcmp(value, i->value, i->value_len);
}

Project: linux
File: xattr.c

ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
		     void *buffer, size_t buffer_size)
{
	struct buffer_head *bh = NULL;
	struct ext4_xattr_entry *entry;
	size_t size;
	void *end;
	int error;
	struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);

	ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
		  name_index, name, buffer, (long)buffer_size);

	error = -ENODATA;
	if (!EXT4_I(inode)->i_file_acl)
		goto cleanup;
	ea_idebug(inode, "reading block %llu",
		  (unsigned long long)EXT4_I(inode)->i_file_acl);
	bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
	if (!bh)
		goto cleanup;
	ea_bdebug(bh, "b_count=%d, refcount=%d",
		atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
	error = ext4_xattr_check_block(inode, bh);
	if (error)
		goto cleanup;
	ext4_xattr_block_cache_insert(ea_block_cache, bh);
	entry = BFIRST(bh);
	end = bh->b_data + bh->b_size;
	error = xattr_find_entry(inode, &entry, end, name_index, name, 1);
	if (error)
		goto cleanup;
	size = le32_to_cpu(entry->e_value_size);
	error = -ERANGE;
	if (unlikely(size > EXT4_XATTR_SIZE_MAX))
		goto cleanup;
	if (buffer) {
		if (size > buffer_size)
			goto cleanup;
		if (entry->e_value_inum) {
			error = ext4_xattr_inode_get(inode, entry, buffer,
						     size);
			if (error)
				goto cleanup;
		} else {
			u16 offset = le16_to_cpu(entry->e_value_offs);
			void *p = bh->b_data + offset;

			if (unlikely(p + size > end))
				goto cleanup;
			memcpy(buffer, p, size);
		}
	}
	error = size;

cleanup:
	brelse(bh);
	return error;
}

Project: linux
File: xattr.c

static void ext4_xattr_inode_free_quota(struct inode *parent,
					struct inode *ea_inode,
					size_t len)
{
	if (ea_inode &&
	    ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE))
		return;
	dquot_free_space_nodirty(parent, round_up_cluster(parent, len));
	dquot_free_inode(parent);
}

Project: linux
File: xattr.c

static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
				    size_t value_count)
{
	__u32 hash = 0;

	while (name_len--) {
		hash = (hash << NAME_HASH_SHIFT) ^
		       (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
		       *name++;
	}
	while (value_count--) {
		hash = (hash << VALUE_HASH_SHIFT) ^
		       (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
		       le32_to_cpu(*value++);
	}
	return cpu_to_le32(hash);
}

Project: linux
File: xattr.c

ext4_xattr_create_cache(void)
{
	return mb_cache_create(HASH_BUCKET_BITS);
}

Project: linux
File: xattr.c

ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
		      struct ext4_xattr_block_find *bs)
{
	struct super_block *sb = inode->i_sb;
	int error;

	ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
		  i->name_index, i->name, i->value, (long)i->value_len);

	if (EXT4_I(inode)->i_file_acl) {
		/* The inode already has an extended attribute block. */
		bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl);
		error = -EIO;
		if (!bs->bh)
			goto cleanup;
		ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
			atomic_read(&(bs->bh->b_count)),
			le32_to_cpu(BHDR(bs->bh)->h_refcount));
		error = ext4_xattr_check_block(inode, bs->bh);
		if (error)
			goto cleanup;
		/* Find the named attribute. */
		bs->s.base = BHDR(bs->bh);
		bs->s.first = BFIRST(bs->bh);
		bs->s.end = bs->bh->b_data + bs->bh->b_size;
		bs->s.here = bs->s.first;
		error = xattr_find_entry(inode, &bs->s.here, bs->s.end,
					 i->name_index, i->name, 1);
		if (error && error != -ENODATA)
			goto cleanup;
		bs->s.not_found = error;
	}
	error = 0;

cleanup:
	return error;
}

Project: linux
File: xattr.c

ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
		     void *buffer, size_t buffer_size)
{
	struct ext4_xattr_ibody_header *header;
	struct ext4_xattr_entry *entry;
	struct ext4_inode *raw_inode;
	struct ext4_iloc iloc;
	size_t size;
	void *end;
	int error;

	if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
		return -ENODATA;
	error = ext4_get_inode_loc(inode, &iloc);
	if (error)
		return error;
	raw_inode = ext4_raw_inode(&iloc);
	header = IHDR(inode, raw_inode);
	end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
	error = xattr_check_inode(inode, header, end);
	if (error)
		goto cleanup;
	entry = IFIRST(header);
	error = xattr_find_entry(inode, &entry, end, name_index, name, 0);
	if (error)
		goto cleanup;
	size = le32_to_cpu(entry->e_value_size);
	error = -ERANGE;
	if (unlikely(size > EXT4_XATTR_SIZE_MAX))
		goto cleanup;
	if (buffer) {
		if (size > buffer_size)
			goto cleanup;
		if (entry->e_value_inum) {
			error = ext4_xattr_inode_get(inode, entry, buffer,
						     size);
			if (error)
				goto cleanup;
		} else {
			u16 offset = le16_to_cpu(entry->e_value_offs);
			void *p = (void *)IFIRST(header) + offset;

			if (unlikely(p + size > end))
				goto cleanup;
			memcpy(buffer, p, size);
		}
	}
	error = size;

cleanup:
	brelse(iloc.bh);
	return error;
}

Project: linux
File: xattr.c

static int ext4_xattr_ensure_credits(handle_t *handle, struct inode *inode,
				     int credits, struct buffer_head *bh,
				     bool dirty, bool block_csum)
{
	int error;

	if (!ext4_handle_valid(handle))
		return 0;

	if (handle->h_buffer_credits >= credits)
		return 0;

	error = ext4_journal_extend(handle, credits - handle->h_buffer_credits);
	if (!error)
		return 0;
	if (error < 0) {
		ext4_warning(inode->i_sb, "Extend journal (error %d)", error);
		return error;
	}

	if (bh && dirty) {
		if (block_csum)
			ext4_xattr_block_csum_set(inode, bh);
		error = ext4_handle_dirty_metadata(handle, NULL, bh);
		if (error) {
			ext4_warning(inode->i_sb, "Handle metadata (error %d)",
				     error);
			return error;
		}
	}

	error = ext4_journal_restart(handle, credits);
	if (error) {
		ext4_warning(inode->i_sb, "Restart journal (error %d)", error);
		return error;
	}

	if (bh) {
		error = ext4_journal_get_write_access(handle, bh);
		if (error) {
			ext4_warning(inode->i_sb,
				     "Get write access failed (error %d)",
				     error);
			return error;
		}
	}
	return 0;
}

Project: linux
File: xattr.c

static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode,
				  const void *buf, int bufsize)
{
	struct buffer_head *bh = NULL;
	unsigned long block = 0;
	int blocksize = ea_inode->i_sb->s_blocksize;
	int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits;
	int csize, wsize = 0;
	int ret = 0;
	int retries = 0;

retry:
	while (ret >= 0 && ret < max_blocks) {
		struct ext4_map_blocks map;
		map.m_lblk = block += ret;
		map.m_len = max_blocks -= ret;

		ret = ext4_map_blocks(handle, ea_inode, &map,
				      EXT4_GET_BLOCKS_CREATE);
		if (ret <= 0) {
			ext4_mark_inode_dirty(handle, ea_inode);
			if (ret == -ENOSPC &&
			    ext4_should_retry_alloc(ea_inode->i_sb, &retries)) {
				ret = 0;
				goto retry;
			}
			break;
		}
	}

	if (ret < 0)
		return ret;

	block = 0;
	while (wsize < bufsize) {
		if (bh != NULL)
			brelse(bh);
		csize = (bufsize - wsize) > blocksize ? blocksize :
								bufsize - wsize;
		bh = ext4_getblk(handle, ea_inode, block, 0);
		if (IS_ERR(bh))
			return PTR_ERR(bh);
		ret = ext4_journal_get_write_access(handle, bh);
		if (ret)
			goto out;

		memcpy(bh->b_data, buf, csize);
		set_buffer_uptodate(bh);
		ext4_handle_dirty_metadata(handle, ea_inode, bh);

		buf += csize;
		wsize += csize;
		block += 1;
	}

	inode_lock(ea_inode);
	i_size_write(ea_inode, wsize);
	ext4_update_i_disksize(ea_inode, wsize);
	inode_unlock(ea_inode);

	ext4_mark_inode_dirty(handle, ea_inode);

out:
	brelse(bh);

	return ret;
}

Project: linux
File: xattr.c

ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
{
	int ret, ret2;

	down_read(&EXT4_I(d_inode(dentry))->xattr_sem);
	ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
	if (ret < 0)
		goto errout;
	if (buffer) {
		buffer += ret;
		buffer_size -= ret;
	}
	ret = ext4_xattr_block_list(dentry, buffer, buffer_size);
	if (ret < 0)
		goto errout;
	ret += ret2;
errout:
	up_read(&EXT4_I(d_inode(dentry))->xattr_sem);
	return ret;
}

Project: linux
File: xattr.c

xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry,
		 void *end, int name_index, const char *name, int sorted)
{
	struct ext4_xattr_entry *entry, *next;
	size_t name_len;
	int cmp = 1;

	if (name == NULL)
		return -EINVAL;
	name_len = strlen(name);
	for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) {
		next = EXT4_XATTR_NEXT(entry);
		if ((void *) next >= end) {
			EXT4_ERROR_INODE(inode, "corrupted xattr entries");
			return -EFSCORRUPTED;
		}
		cmp = name_index - entry->e_name_index;
		if (!cmp)
			cmp = name_len - entry->e_name_len;
		if (!cmp)
			cmp = memcmp(name, entry->e_name, name_len);
		if (cmp <= 0 && (sorted || cmp == 0))
			break;
	}
	*pentry = entry;
	return cmp ? -ENODATA : 0;
}

Project: linux
File: xattr.c

void ext4_xattr_inode_set_class(struct inode *ea_inode)
{
	lockdep_set_subclass(&ea_inode->i_rwsem, 1);
}

Project: linux
File: xattr.c

static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode)
{
	return ext4_xattr_inode_update_ref(handle, ea_inode, -1);
}

Project: linux
File: xattr.c

ext4_xattr_cmp(struct ext4_xattr_header *header1,
	       struct ext4_xattr_header *header2)
{
	struct ext4_xattr_entry *entry1, *entry2;

	entry1 = ENTRY(header1+1);
	entry2 = ENTRY(header2+1);
	while (!IS_LAST_ENTRY(entry1)) {
		if (IS_LAST_ENTRY(entry2))
			return 1;
		if (entry1->e_hash != entry2->e_hash ||
		    entry1->e_name_index != entry2->e_name_index ||
		    entry1->e_name_len != entry2->e_name_len ||
		    entry1->e_value_size != entry2->e_value_size ||
		    entry1->e_value_inum != entry2->e_value_inum ||
		    memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
			return 1;
		if (!entry1->e_value_inum &&
		    memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
			   (char *)header2 + le16_to_cpu(entry2->e_value_offs),
			   le32_to_cpu(entry1->e_value_size)))
			return 1;

		entry1 = EXT4_XATTR_NEXT(entry1);
		entry2 = EXT4_XATTR_NEXT(entry2);
	}
	if (!IS_LAST_ENTRY(entry2))
		return 1;
	return 0;
}

Project: linux
File: xattr.c

ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end,
			 void *value_start)
{
	struct ext4_xattr_entry *e = entry;

	/* Find the end of the names list */
	while (!IS_LAST_ENTRY(e)) {
		struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
		if ((void *)next >= end)
			return -EFSCORRUPTED;
		e = next;
	}

	/* Check the values */
	while (!IS_LAST_ENTRY(entry)) {
		u32 size = le32_to_cpu(entry->e_value_size);

		if (size > EXT4_XATTR_SIZE_MAX)
			return -EFSCORRUPTED;

		if (size != 0 && entry->e_value_inum == 0) {
			u16 offs = le16_to_cpu(entry->e_value_offs);
			void *value;

			/*
			 * The value cannot overlap the names, and the value
			 * with padding cannot extend beyond 'end'.  Check both
			 * the padded and unpadded sizes, since the size may
			 * overflow to 0 when adding padding.
			 */
			if (offs > end - value_start)
				return -EFSCORRUPTED;
			value = value_start + offs;
			if (value < (void *)e + sizeof(u32) ||
			    size > end - value ||
			    EXT4_XATTR_SIZE(size) > end - value)
				return -EFSCORRUPTED;
		}
		entry = EXT4_XATTR_NEXT(entry);
	}

	return 0;
}

Project: linux
File: xattr.c

static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode)
{
	return (u32)ea_inode->i_atime.tv_sec;
}

Project: linux
File: xattr.c

ext4_xattr_release_block(handle_t *handle, struct inode *inode,
			 struct buffer_head *bh,
			 struct ext4_xattr_inode_array **ea_inode_array,
			 int extra_credits)
{
	struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
	u32 hash, ref;
	int error = 0;

	BUFFER_TRACE(bh, "get_write_access");
	error = ext4_journal_get_write_access(handle, bh);
	if (error)
		goto out;

	lock_buffer(bh);
	hash = le32_to_cpu(BHDR(bh)->h_hash);
	ref = le32_to_cpu(BHDR(bh)->h_refcount);
	if (ref == 1) {
		ea_bdebug(bh, "refcount now=0; freeing");
		/*
		 * This must happen under buffer lock for
		 * ext4_xattr_block_set() to reliably detect freed block
		 */
		if (ea_block_cache)
			mb_cache_entry_delete(ea_block_cache, hash,
					      bh->b_blocknr);
		get_bh(bh);
		unlock_buffer(bh);

		if (ext4_has_feature_ea_inode(inode->i_sb))
			ext4_xattr_inode_dec_ref_all(handle, inode, bh,
						     BFIRST(bh),
						     true /* block_csum */,
						     ea_inode_array,
						     extra_credits,
						     true /* skip_quota */);
		ext4_free_blocks(handle, inode, bh, 0, 1,
				 EXT4_FREE_BLOCKS_METADATA |
				 EXT4_FREE_BLOCKS_FORGET);
	} else {
		ref--;
		BHDR(bh)->h_refcount = cpu_to_le32(ref);
		if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) {
			struct mb_cache_entry *ce;

			if (ea_block_cache) {
				ce = mb_cache_entry_get(ea_block_cache, hash,
							bh->b_blocknr);
				if (ce) {
					ce->e_reusable = 1;
					mb_cache_entry_put(ea_block_cache, ce);
				}
			}
		}

		ext4_xattr_block_csum_set(inode, bh);
		/*
		 * Beware of this ugliness: Releasing of xattr block references
		 * from different inodes can race and so we have to protect
		 * from a race where someone else frees the block (and releases
		 * its journal_head) before we are done dirtying the buffer. In
		 * nojournal mode this race is harmless and we actually cannot
		 * call ext4_handle_dirty_metadata() with locked buffer as
		 * that function can call sync_dirty_buffer() so for that case
		 * we handle the dirtying after unlocking the buffer.
		 */
		if (ext4_handle_valid(handle))
			error = ext4_handle_dirty_metadata(handle, inode, bh);
		unlock_buffer(bh);
		if (!ext4_handle_valid(handle))
			error = ext4_handle_dirty_metadata(handle, inode, bh);
		if (IS_SYNC(inode))
			ext4_handle_sync(handle);
		dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1));
		ea_bdebug(bh, "refcount now=%d; releasing",
			  le32_to_cpu(BHDR(bh)->h_refcount));
	}
out:
	ext4_std_error(inode->i_sb, error);
	return;
}

Project: linux
File: xattr.c

int ext4_get_inode_usage(struct inode *inode, qsize_t *usage)
{
	struct ext4_iloc iloc = { .bh = NULL };
	struct buffer_head *bh = NULL;
	struct ext4_inode *raw_inode;
	struct ext4_xattr_ibody_header *header;
	struct ext4_xattr_entry *entry;
	qsize_t ea_inode_refs = 0;
	void *end;
	int ret;

	lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem);

	if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
		ret = ext4_get_inode_loc(inode, &iloc);
		if (ret)
			goto out;
		raw_inode = ext4_raw_inode(&iloc);
		header = IHDR(inode, raw_inode);
		end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
		ret = xattr_check_inode(inode, header, end);
		if (ret)
			goto out;

		for (entry = IFIRST(header); !IS_LAST_ENTRY(entry);
		     entry = EXT4_XATTR_NEXT(entry))
			if (entry->e_value_inum)
				ea_inode_refs++;
	}

	if (EXT4_I(inode)->i_file_acl) {
		bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
		if (!bh) {
			ret = -EIO;
			goto out;
		}

		ret = ext4_xattr_check_block(inode, bh);
		if (ret)
			goto out;

		for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
		     entry = EXT4_XATTR_NEXT(entry))
			if (entry->e_value_inum)
				ea_inode_refs++;
	}
	*usage = ea_inode_refs + 1;
	ret = 0;
out:
	brelse(iloc.bh);
	brelse(bh);
	return ret;
}

Project: linux
File: xattr.c

ext4_xattr_block_cache_find(struct inode *inode,
			    struct ext4_xattr_header *header,
			    struct mb_cache_entry **pce)
{
	__u32 hash = le32_to_cpu(header->h_hash);
	struct mb_cache_entry *ce;
	struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);

	if (!ea_block_cache)
		return NULL;
	if (!header->h_hash)
		return NULL;  /* never share */
	ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
	ce = mb_cache_entry_find_first(ea_block_cache, hash);
	while (ce) {
		struct buffer_head *bh;

		bh = sb_bread(inode->i_sb, ce->e_value);
		if (!bh) {
			EXT4_ERROR_INODE(inode, "block %lu read error",
					 (unsigned long)ce->e_value);
		} else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
			*pce = ce;
			return bh;
		}
		brelse(bh);
		ce = mb_cache_entry_find_next(ea_block_cache, ce);
	}
	return NULL;
}

Project: linux
File: xattr.c

ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
			struct inode *inode)
{
	if (*ea_inode_array == NULL) {
		/*
		 * Start with 15 inodes, so it fits into a power-of-two size.
		 * If *ea_inode_array is NULL, this is essentially offsetof()
		 */
		(*ea_inode_array) =
			kmalloc(offsetof(struct ext4_xattr_inode_array,
					 inodes[EIA_MASK]),
				GFP_NOFS);
		if (*ea_inode_array == NULL)
			return -ENOMEM;
		(*ea_inode_array)->count = 0;
	} else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) {
		/* expand the array once all 15 + n * 16 slots are full */
		struct ext4_xattr_inode_array *new_array = NULL;
		int count = (*ea_inode_array)->count;

		/* if new_array is NULL, this is essentially offsetof() */
		new_array = kmalloc(
				offsetof(struct ext4_xattr_inode_array,
					 inodes[count + EIA_INCR]),
				GFP_NOFS);
		if (new_array == NULL)
			return -ENOMEM;
		memcpy(new_array, *ea_inode_array,
		       offsetof(struct ext4_xattr_inode_array, inodes[count]));
		kfree(*ea_inode_array);
		*ea_inode_array = new_array;
	}
	(*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode;
	return 0;
}

Project: linux
File: xattr.c

ext4_xattr_get(struct inode *inode, int name_index, const char *name,
	       void *buffer, size_t buffer_size)
{
	int error;

	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
		return -EIO;

	if (strlen(name) > 255)
		return -ERANGE;

	down_read(&EXT4_I(inode)->xattr_sem);
	error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
				     buffer_size);
	if (error == -ENODATA)
		error = ext4_xattr_block_get(inode, name_index, name, buffer,
					     buffer_size);
	up_read(&EXT4_I(inode)->xattr_sem);
	return error;
}

Project: linux
File: xattr.c

static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent,
					struct ext4_xattr_entry *first)
{
	struct inode *ea_inode;
	struct ext4_xattr_entry *entry;
	struct ext4_xattr_entry *failed_entry;
	unsigned int ea_ino;
	int err, saved_err;

	for (entry = first; !IS_LAST_ENTRY(entry);
	     entry = EXT4_XATTR_NEXT(entry)) {
		if (!entry->e_value_inum)
			continue;
		ea_ino = le32_to_cpu(entry->e_value_inum);
		err = ext4_xattr_inode_iget(parent, ea_ino,
					    le32_to_cpu(entry->e_hash),
					    &ea_inode);
		if (err)
			goto cleanup;
		err = ext4_xattr_inode_inc_ref(handle, ea_inode);
		if (err) {
			ext4_warning_inode(ea_inode, "inc ref error %d", err);
			iput(ea_inode);
			goto cleanup;
		}
		iput(ea_inode);
	}
	return 0;

cleanup:
	saved_err = err;
	failed_entry = entry;

	for (entry = first; entry != failed_entry;
	     entry = EXT4_XATTR_NEXT(entry)) {
		if (!entry->e_value_inum)
			continue;
		ea_ino = le32_to_cpu(entry->e_value_inum);
		err = ext4_xattr_inode_iget(parent, ea_ino,
					    le32_to_cpu(entry->e_hash),
					    &ea_inode);
		if (err) {
			ext4_warning(parent->i_sb,
				     "cleanup ea_ino %u iget error %d", ea_ino,
				     err);
			continue;
		}
		err = ext4_xattr_inode_dec_ref(handle, ea_inode);
		if (err)
			ext4_warning_inode(ea_inode, "cleanup dec ref error %d",
					   err);
		iput(ea_inode);
	}
	return saved_err;
}

Project: linux
File: xattr.c

static int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
				struct ext4_xattr_info *i,
				struct ext4_xattr_ibody_find *is)
{
	struct ext4_xattr_ibody_header *header;
	struct ext4_xattr_search *s = &is->s;
	int error;

	if (EXT4_I(inode)->i_extra_isize == 0)
		return -ENOSPC;
	error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
	if (error)
		return error;
	header = IHDR(inode, ext4_raw_inode(&is->iloc));
	if (!IS_LAST_ENTRY(s->first)) {
		header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
		ext4_set_inode_state(inode, EXT4_STATE_XATTR);
	} else {
		header->h_magic = cpu_to_le32(0);
		ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
	}
	return 0;
}

Project: linux
File: xattr.c

static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
				    struct ext4_inode *raw_inode,
				    struct ext4_xattr_entry *entry)
{
	struct ext4_xattr_ibody_find *is = NULL;
	struct ext4_xattr_block_find *bs = NULL;
	char *buffer = NULL, *b_entry_name = NULL;
	size_t value_size = le32_to_cpu(entry->e_value_size);
	struct ext4_xattr_info i = {
		.value = NULL,
		.value_len = 0,
		.name_index = entry->e_name_index,
		.in_inode = !!entry->e_value_inum,
	};
	struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
	int error;

	is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
	bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
	buffer = kmalloc(value_size, GFP_NOFS);
	b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
	if (!is || !bs || !buffer || !b_entry_name) {
		error = -ENOMEM;
		goto out;
	}

	is->s.not_found = -ENODATA;
	bs->s.not_found = -ENODATA;
	is->iloc.bh = NULL;
	bs->bh = NULL;

	/* Save the entry name and the entry value */
	if (entry->e_value_inum) {
		error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
		if (error)
			goto out;
	} else {
		size_t value_offs = le16_to_cpu(entry->e_value_offs);
		memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size);
	}

	memcpy(b_entry_name, entry->e_name, entry->e_name_len);
	b_entry_name[entry->e_name_len] = '\0';
	i.name = b_entry_name;

	error = ext4_get_inode_loc(inode, &is->iloc);
	if (error)
		goto out;

	error = ext4_xattr_ibody_find(inode, &i, is);
	if (error)
		goto out;

	/* Remove the chosen entry from the inode */
	error = ext4_xattr_ibody_set(handle, inode, &i, is);
	if (error)
		goto out;

	i.value = buffer;
	i.value_len = value_size;
	error = ext4_xattr_block_find(inode, &i, bs);
	if (error)
		goto out;

	/* Add entry which was removed from the inode into the block */
	error = ext4_xattr_block_set(handle, inode, &i, bs);
	if (error)
		goto out;
	error = 0;
out:
	kfree(b_entry_name);
	kfree(buffer);
	if (is)
		brelse(is->iloc.bh);
	kfree(is);
	kfree(bs);

	return error;
}

Project: linux
File: xattr.c

static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
				     int value_offs_shift, void *to,
				     void *from, size_t n)
{
	struct ext4_xattr_entry *last = entry;
	int new_offs;

	/* We always shift xattr headers further thus offsets get lower */
	BUG_ON(value_offs_shift > 0);

	/* Adjust the value offsets of the entries */
	for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
		if (!last->e_value_inum && last->e_value_size) {
			new_offs = le16_to_cpu(last->e_value_offs) +
							value_offs_shift;
			last->e_value_offs = cpu_to_le16(new_offs);
		}
	}
	/* Shift the entries by n bytes */
	memmove(to, from, n);
}

Project: linux
File: xattr.c

ext4_xattr_inode_verify_hashes(struct inode *ea_inode,
			       struct ext4_xattr_entry *entry, void *buffer,
			       size_t size)
{
	u32 hash;

	/* Verify stored hash matches calculated hash. */
	hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size);
	if (hash != ext4_xattr_inode_get_hash(ea_inode))
		return -EFSCORRUPTED;

	if (entry) {
		__le32 e_hash, tmp_data;

		/* Verify entry hash. */
		tmp_data = cpu_to_le32(hash);
		e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len,
					       &tmp_data, 1);
		if (e_hash != entry->e_hash)
			return -EFSCORRUPTED;
	}
	return 0;
}

Project: linux
File: xattr.c

static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash)
{
	ea_inode->i_atime.tv_sec = hash;
}

Project: linux
File: xattr.c

ext4_xattr_block_set(handle_t *handle, struct inode *inode,
		     struct ext4_xattr_info *i,
		     struct ext4_xattr_block_find *bs)
{
	struct super_block *sb = inode->i_sb;
	struct buffer_head *new_bh = NULL;
	struct ext4_xattr_search s_copy = bs->s;
	struct ext4_xattr_search *s = &s_copy;
	struct mb_cache_entry *ce = NULL;
	int error = 0;
	struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
	struct inode *ea_inode = NULL, *tmp_inode;
	size_t old_ea_inode_quota = 0;
	unsigned int ea_ino;


#define header(x) ((struct ext4_xattr_header *)(x))

	if (s->base) {
		BUFFER_TRACE(bs->bh, "get_write_access");
		error = ext4_journal_get_write_access(handle, bs->bh);
		if (error)
			goto cleanup;
		lock_buffer(bs->bh);

		if (header(s->base)->h_refcount == cpu_to_le32(1)) {
			__u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash);

			/*
			 * This must happen under buffer lock for
			 * ext4_xattr_block_set() to reliably detect modified
			 * block
			 */
			if (ea_block_cache)
				mb_cache_entry_delete(ea_block_cache, hash,
						      bs->bh->b_blocknr);
			ea_bdebug(bs->bh, "modifying in-place");
			error = ext4_xattr_set_entry(i, s, handle, inode,
						     true /* is_block */);
			ext4_xattr_block_csum_set(inode, bs->bh);
			unlock_buffer(bs->bh);
			if (error == -EFSCORRUPTED)
				goto bad_block;
			if (!error)
				error = ext4_handle_dirty_metadata(handle,
								   inode,
								   bs->bh);
			if (error)
				goto cleanup;
			goto inserted;
		} else {
			int offset = (char *)s->here - bs->bh->b_data;

			unlock_buffer(bs->bh);
			ea_bdebug(bs->bh, "cloning");
			s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
			error = -ENOMEM;
			if (s->base == NULL)
				goto cleanup;
			memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
			s->first = ENTRY(header(s->base)+1);
			header(s->base)->h_refcount = cpu_to_le32(1);
			s->here = ENTRY(s->base + offset);
			s->end = s->base + bs->bh->b_size;

			/*
			 * If existing entry points to an xattr inode, we need
			 * to prevent ext4_xattr_set_entry() from decrementing
			 * ref count on it because the reference belongs to the
			 * original block. In this case, make the entry look
			 * like it has an empty value.
			 */
			if (!s->not_found && s->here->e_value_inum) {
				ea_ino = le32_to_cpu(s->here->e_value_inum);
				error = ext4_xattr_inode_iget(inode, ea_ino,
					      le32_to_cpu(s->here->e_hash),
					      &tmp_inode);
				if (error)
					goto cleanup;

				if (!ext4_test_inode_state(tmp_inode,
						EXT4_STATE_LUSTRE_EA_INODE)) {
					/*
					 * Defer quota free call for previous
					 * inode until success is guaranteed.
					 */
					old_ea_inode_quota = le32_to_cpu(
							s->here->e_value_size);
				}
				iput(tmp_inode);

				s->here->e_value_inum = 0;
				s->here->e_value_size = 0;
			}
		}
	} else {
		/* Allocate a buffer where we construct the new block. */
		s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
		/* assert(header == s->base) */
		error = -ENOMEM;
		if (s->base == NULL)
			goto cleanup;
		header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
		header(s->base)->h_blocks = cpu_to_le32(1);
		header(s->base)->h_refcount = cpu_to_le32(1);
		s->first = ENTRY(header(s->base)+1);
		s->here = ENTRY(header(s->base)+1);
		s->end = s->base + sb->s_blocksize;
	}

	error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */);
	if (error == -EFSCORRUPTED)
		goto bad_block;
	if (error)
		goto cleanup;

	if (i->value && s->here->e_value_inum) {
		/*
		 * A ref count on ea_inode has been taken as part of the call to
		 * ext4_xattr_set_entry() above. We would like to drop this
		 * extra ref but we have to wait until the xattr block is
		 * initialized and has its own ref count on the ea_inode.
		 */
		ea_ino = le32_to_cpu(s->here->e_value_inum);
		error = ext4_xattr_inode_iget(inode, ea_ino,
					      le32_to_cpu(s->here->e_hash),
					      &ea_inode);
		if (error) {
			ea_inode = NULL;
			goto cleanup;
		}
	}

inserted:
	if (!IS_LAST_ENTRY(s->first)) {
		new_bh = ext4_xattr_block_cache_find(inode, header(s->base),
						     &ce);
		if (new_bh) {
			/* We found an identical block in the cache. */
			if (new_bh == bs->bh)
				ea_bdebug(new_bh, "keeping");
			else {
				u32 ref;

				WARN_ON_ONCE(dquot_initialize_needed(inode));

				/* The old block is released after updating
				   the inode. */
				error = dquot_alloc_block(inode,
						EXT4_C2B(EXT4_SB(sb), 1));
				if (error)
					goto cleanup;
				BUFFER_TRACE(new_bh, "get_write_access");
				error = ext4_journal_get_write_access(handle,
								      new_bh);
				if (error)
					goto cleanup_dquot;
				lock_buffer(new_bh);
				/*
				 * We have to be careful about races with
				 * freeing, rehashing or adding references to
				 * xattr block. Once we hold buffer lock xattr
				 * block's state is stable so we can check
				 * whether the block got freed / rehashed or
				 * not.  Since we unhash mbcache entry under
				 * buffer lock when freeing / rehashing xattr
				 * block, checking whether entry is still
				 * hashed is reliable. Same rules hold for
				 * e_reusable handling.
				 */
				if (hlist_bl_unhashed(&ce->e_hash_list) ||
				    !ce->e_reusable) {
					/*
					 * Undo everything and check mbcache
					 * again.
					 */
					unlock_buffer(new_bh);
					dquot_free_block(inode,
							 EXT4_C2B(EXT4_SB(sb),
								  1));
					brelse(new_bh);
					mb_cache_entry_put(ea_block_cache, ce);
					ce = NULL;
					new_bh = NULL;
					goto inserted;
				}
				ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1;
				BHDR(new_bh)->h_refcount = cpu_to_le32(ref);
				if (ref >= EXT4_XATTR_REFCOUNT_MAX)
					ce->e_reusable = 0;
				ea_bdebug(new_bh, "reusing; refcount now=%d",
					  ref);
				ext4_xattr_block_csum_set(inode, new_bh);
				unlock_buffer(new_bh);
				error = ext4_handle_dirty_metadata(handle,
								   inode,
								   new_bh);
				if (error)
					goto cleanup_dquot;
			}
			mb_cache_entry_touch(ea_block_cache, ce);
			mb_cache_entry_put(ea_block_cache, ce);
			ce = NULL;
		} else if (bs->bh && s->base == bs->bh->b_data) {
			/* We were modifying this block in-place. */
			ea_bdebug(bs->bh, "keeping this block");
			ext4_xattr_block_cache_insert(ea_block_cache, bs->bh);
			new_bh = bs->bh;
			get_bh(new_bh);
		} else {
			/* We need to allocate a new block */
			ext4_fsblk_t goal, block;

			WARN_ON_ONCE(dquot_initialize_needed(inode));

			goal = ext4_group_first_block_no(sb,
						EXT4_I(inode)->i_block_group);

			/* non-extent files can't have physical blocks past 2^32 */
			if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
				goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;

			block = ext4_new_meta_blocks(handle, inode, goal, 0,
						     NULL, &error);
			if (error)
				goto cleanup;

			if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
				BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS);

			ea_idebug(inode, "creating block %llu",
				  (unsigned long long)block);

			new_bh = sb_getblk(sb, block);
			if (unlikely(!new_bh)) {
				error = -ENOMEM;
getblk_failed:
				ext4_free_blocks(handle, inode, NULL, block, 1,
						 EXT4_FREE_BLOCKS_METADATA);
				goto cleanup;
			}
			error = ext4_xattr_inode_inc_ref_all(handle, inode,
						      ENTRY(header(s->base)+1));
			if (error)
				goto getblk_failed;
			if (ea_inode) {
				/* Drop the extra ref on ea_inode. */
				error = ext4_xattr_inode_dec_ref(handle,
								 ea_inode);
				if (error)
					ext4_warning_inode(ea_inode,
							   "dec ref error=%d",
							   error);
				iput(ea_inode);
				ea_inode = NULL;
			}

			lock_buffer(new_bh);
			error = ext4_journal_get_create_access(handle, new_bh);
			if (error) {
				unlock_buffer(new_bh);
				error = -EIO;
				goto getblk_failed;
			}
			memcpy(new_bh->b_data, s->base, new_bh->b_size);
			ext4_xattr_block_csum_set(inode, new_bh);
			set_buffer_uptodate(new_bh);
			unlock_buffer(new_bh);
			ext4_xattr_block_cache_insert(ea_block_cache, new_bh);
			error = ext4_handle_dirty_metadata(handle, inode,
							   new_bh);
			if (error)
				goto cleanup;
		}
	}

	if (old_ea_inode_quota)
		ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota);

	/* Update the inode. */
	EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;

	/* Drop the previous xattr block. */
	if (bs->bh && bs->bh != new_bh) {
		struct ext4_xattr_inode_array *ea_inode_array = NULL;

		ext4_xattr_release_block(handle, inode, bs->bh,
					 &ea_inode_array,
					 0 /* extra_credits */);
		ext4_xattr_inode_array_free(ea_inode_array);
	}
	error = 0;

cleanup:
	if (ea_inode) {
		int error2;

		error2 = ext4_xattr_inode_dec_ref(handle, ea_inode);
		if (error2)
			ext4_warning_inode(ea_inode, "dec ref error=%d",
					   error2);

		/* If there was an error, revert the quota charge. */
		if (error)
			ext4_xattr_inode_free_quota(inode, ea_inode,
						    i_size_read(ea_inode));
		iput(ea_inode);
	}
	if (ce)
		mb_cache_entry_put(ea_block_cache, ce);
	brelse(new_bh);
	if (!(bs->bh && s->base == bs->bh->b_data))
		kfree(s->base);

	return error;

cleanup_dquot:
	dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1));
	goto cleanup;

bad_block:
	EXT4_ERROR_INODE(inode, "bad block %llu",
			 EXT4_I(inode)->i_file_acl);
	goto cleanup;

#undef header
}

Project: linux
File: xattr.c

__ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh,
			 const char *function, unsigned int line)
{
	int error = -EFSCORRUPTED;

	if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
	    BHDR(bh)->h_blocks != cpu_to_le32(1))
		goto errout;
	if (buffer_verified(bh))
		return 0;

	error = -EFSBADCRC;
	if (!ext4_xattr_block_csum_verify(inode, bh))
		goto errout;
	error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size,
					 bh->b_data);
errout:
	if (error)
		__ext4_error_inode(inode, function, line, 0,
				   "corrupted xattr block %llu",
				   (unsigned long long) bh->b_blocknr);
	else
		set_buffer_verified(bh);
	return error;
}

Project: linux
File: xattr.c

static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
				    size_t *min_offs, void *base, int *total)
{
	for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
		if (!last->e_value_inum && last->e_value_size) {
			size_t offs = le16_to_cpu(last->e_value_offs);
			if (offs < *min_offs)
				*min_offs = offs;
		}
		if (total)
			*total += EXT4_XATTR_LEN(last->e_name_len);
	}
	return (*min_offs - ((void *)last - base) - sizeof(__u32));
}

Project: linux
File: xattr.c

static int ext4_xattr_block_csum_verify(struct inode *inode,
					struct buffer_head *bh)
{
	struct ext4_xattr_header *hdr = BHDR(bh);
	int ret = 1;

	if (ext4_has_metadata_csum(inode->i_sb)) {
		lock_buffer(bh);
		ret = (hdr->h_checksum == ext4_xattr_block_csum(inode,
							bh->b_blocknr, hdr));
		unlock_buffer(bh);
	}
	return ret;
}

Project: linux
File: xattr.c

static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode,
					  const void *value, size_t value_len,
					  struct inode **ret_inode)
{
	struct inode *ea_inode;
	u32 hash;
	int err;

	hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len);
	ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash);
	if (ea_inode) {
		err = ext4_xattr_inode_inc_ref(handle, ea_inode);
		if (err) {
			iput(ea_inode);
			return err;
		}

		*ret_inode = ea_inode;
		return 0;
	}

	/* Create an inode for the EA value */
	ea_inode = ext4_xattr_inode_create(handle, inode, hash);
	if (IS_ERR(ea_inode))
		return PTR_ERR(ea_inode);

	err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
	if (err) {
		ext4_xattr_inode_dec_ref(handle, ea_inode);
		iput(ea_inode);
		return err;
	}

	if (EA_INODE_CACHE(inode))
		mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash,
				      ea_inode->i_ino, true /* reusable */);

	*ret_inode = ea_inode;
	return 0;
}

Project: linux
File: xattr.c

static __le32 ext4_xattr_block_csum(struct inode *inode,
				    sector_t block_nr,
				    struct ext4_xattr_header *hdr)
{
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
	__u32 csum;
	__le64 dsk_block_nr = cpu_to_le64(block_nr);
	__u32 dummy_csum = 0;
	int offset = offsetof(struct ext4_xattr_header, h_checksum);

	csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr,
			   sizeof(dsk_block_nr));
	csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset);
	csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
	offset += sizeof(dummy_csum);
	csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset,
			   EXT4_BLOCK_SIZE(inode->i_sb) - offset);

	return cpu_to_le32(csum);
}

Project: linux
File: xattr.c

ext4_xattr_handler(int name_index)
{
	const struct xattr_handler *handler = NULL;

	if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map))
		handler = ext4_xattr_handler_map[name_index];
	return handler;
}