Commit message: ext4: avoid hang when mounting non-journal filesystems with orphan list

When trying to mount a file system which does not contain a journal,
but which does have a orphan list containing an inode which needs to
be truncated, the mount call with hang forever in
ext4_orphan_cleanup() because ext4_orphan_del() will return
immediately without removing the inode from the orphan list, leading
to an uninterruptible loop in kernel code which will busy out one of
the CPU's on the system.

This can be trivially reproduced by trying to mount the file system
found in tests/f_orphan_extents_inode/image.gz from the e2fsprogs
source tree.  If a malicious user were to put this on a USB stick, and
mount it on a Linux desktop which has automatic mounts enabled, this
could be considered a potential denial of service attack.  (Not a big
deal in practice, but professional paranoids worry about such things,
and have even been known to allocate CVE numbers for such problems.)

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Cc: stable@vger.kernel.org
CVE: CVE-2013-2015
CWE: CWE-399
Vulnerability description: The ext4_orphan_del function in fs/ext4/namei.c in the Linux kernel before 3.7.3 does not properly handle orphan-list entries for non-journal filesystems, which allows physically proximate attackers to cause a denial of service (system hang) via a crafted filesystem on removable media, as demonstrated by the e2fsprogs tests/f_orphan_extents_inode/image.gz test.

Project: linux
File: namei.c

static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
			     struct inode *inode, struct ext4_dir_entry_2 *de,
			     struct buffer_head *bh)
{
	struct inode	*dir = dentry->d_parent->d_inode;
	const char	*name = dentry->d_name.name;
	int		namelen = dentry->d_name.len;
	unsigned int	blocksize = dir->i_sb->s_blocksize;
	unsigned short	reclen;
	int		csum_size = 0;
	int		err;

	if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
		csum_size = sizeof(struct ext4_dir_entry_tail);

	reclen = EXT4_DIR_REC_LEN(namelen);
	if (!de) {
		err = ext4_find_dest_de(dir, inode,
					bh, bh->b_data, blocksize - csum_size,
					name, namelen, &de);
		if (err)
			return err;
	}
	BUFFER_TRACE(bh, "get_write_access");
	err = ext4_journal_get_write_access(handle, bh);
	if (err) {
		ext4_std_error(dir->i_sb, err);
		return err;
	}

	/* By now the buffer is marked for journaling */
	ext4_insert_dentry(inode, de, blocksize, name, namelen);

	/*
	 * XXX shouldn't update any times until successful
	 * completion of syscall, but too many callers depend
	 * on this.
	 *
	 * XXX similarly, too many callers depend on
	 * ext4_new_inode() setting the times, but error
	 * recovery deletes the inode, so the worst that can
	 * happen is that the times are slightly out of date
	 * and/or different from the directory change time.
	 */
	dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
	ext4_update_dx_flag(dir);
	dir->i_version++;
	ext4_mark_inode_dirty(handle, dir);
	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
	err = ext4_handle_dirty_dirent_node(handle, dir, bh);
	if (err)
		ext4_std_error(dir->i_sb, err);
	return 0;
}

Project: linux
File: namei.c

static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
			struct buffer_head **bh,struct dx_frame *frame,
			struct dx_hash_info *hinfo, int *error)
{
	unsigned blocksize = dir->i_sb->s_blocksize;
	unsigned count, continued;
	struct buffer_head *bh2;
	ext4_lblk_t newblock;
	u32 hash2;
	struct dx_map_entry *map;
	char *data1 = (*bh)->b_data, *data2;
	unsigned split, move, size;
	struct ext4_dir_entry_2 *de = NULL, *de2;
	struct ext4_dir_entry_tail *t;
	int	csum_size = 0;
	int	err = 0, i;

	if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
		csum_size = sizeof(struct ext4_dir_entry_tail);

	bh2 = ext4_append (handle, dir, &newblock, &err);
	if (!(bh2)) {
		brelse(*bh);
		*bh = NULL;
		goto errout;
	}

	BUFFER_TRACE(*bh, "get_write_access");
	err = ext4_journal_get_write_access(handle, *bh);
	if (err)
		goto journal_error;

	BUFFER_TRACE(frame->bh, "get_write_access");
	err = ext4_journal_get_write_access(handle, frame->bh);
	if (err)
		goto journal_error;

	data2 = bh2->b_data;

	/* create map in the end of data2 block */
	map = (struct dx_map_entry *) (data2 + blocksize);
	count = dx_make_map((struct ext4_dir_entry_2 *) data1,
			     blocksize, hinfo, map);
	map -= count;
	dx_sort_map(map, count);
	/* Split the existing block in the middle, size-wise */
	size = 0;
	move = 0;
	for (i = count-1; i >= 0; i--) {
		/* is more than half of this entry in 2nd half of the block? */
		if (size + map[i].size/2 > blocksize/2)
			break;
		size += map[i].size;
		move++;
	}
	/* map index at which we will split */
	split = count - move;
	hash2 = map[split].hash;
	continued = hash2 == map[split - 1].hash;
	dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
			(unsigned long)dx_get_block(frame->at),
					hash2, split, count-split));

	/* Fancy dance to stay within two buffers */
	de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
	de = dx_pack_dirents(data1, blocksize);
	de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
					   (char *) de,
					   blocksize);
	de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
					    (char *) de2,
					    blocksize);
	if (csum_size) {
		t = EXT4_DIRENT_TAIL(data2, blocksize);
		initialize_dirent_tail(t, blocksize);

		t = EXT4_DIRENT_TAIL(data1, blocksize);
		initialize_dirent_tail(t, blocksize);
	}

	dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
	dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));

	/* Which block gets the new entry? */
	if (hinfo->hash >= hash2)
	{
		swap(*bh, bh2);
		de = de2;
	}
	dx_insert_block(frame, hash2 + continued, newblock);
	err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
	if (err)
		goto journal_error;
	err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
	if (err)
		goto journal_error;
	brelse(bh2);
	dxtrace(dx_show_index("frame", frame->entries));
	return de;

journal_error:
	brelse(*bh);
	brelse(bh2);
	*bh = NULL;
	ext4_std_error(dir->i_sb, err);
errout:
	*error = err;
	return NULL;
}

Project: linux
File: namei.c

static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
{
	return le32_to_cpu(entry->block) & 0x00ffffff;
}

Project: linux
File: namei.c

static inline unsigned dx_get_count(struct dx_entry *entries)
{
	return le16_to_cpu(((struct dx_countlimit *) entries)->count);
}

Project: linux
File: namei.c

static inline unsigned dx_get_hash(struct dx_entry *entry)
{
	return le32_to_cpu(entry->hash);
}

Project: linux
File: namei.c

static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
{
	struct dx_entry *entries = frame->entries;
	struct dx_entry *old = frame->at, *new = old + 1;
	int count = dx_get_count(entries);

	assert(count < dx_get_limit(entries));
	assert(old < entries + count);
	memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
	dx_set_hash(new, hash);
	dx_set_block(new, block);
	dx_set_count(entries, count + 1);
}

Project: linux
File: namei.c

static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
		       struct dx_hash_info *hinfo,
		       struct dx_map_entry *map_tail)
{
	int count = 0;
	char *base = (char *) de;
	struct dx_hash_info h = *hinfo;

	while ((char *) de < base + blocksize) {
		if (de->name_len && de->inode) {
			ext4fs_dirhash(de->name, de->name_len, &h);
			map_tail--;
			map_tail->hash = h.hash;
			map_tail->offs = ((char *) de - base)>>2;
			map_tail->size = le16_to_cpu(de->rec_len);
			count++;
			cond_resched();
		}
		/* XXX: do we need to check rec_len == 0 case? -Chris */
		de = ext4_next_entry(de, blocksize);
	}
	return count;
}

Project: linux
File: namei.c

static inline unsigned dx_node_limit(struct inode *dir)
{
	unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);

	if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
		entry_space -= sizeof(struct dx_tail);
	return entry_space / sizeof(struct dx_entry);
}

Project: linux
File: namei.c

static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
{
	struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
	unsigned rec_len = 0;

	prev = to = de;
	while ((char*)de < base + blocksize) {
		next = ext4_next_entry(de, blocksize);
		if (de->inode && de->name_len) {
			rec_len = EXT4_DIR_REC_LEN(de->name_len);
			if (de > to)
				memmove(to, de, rec_len);
			to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
			prev = to;
			to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
		}
		de = next;
	}
	return prev;
}

Project: linux
File: namei.c

dx_probe(const struct qstr *d_name, struct inode *dir,
	 struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
{
	unsigned count, indirect;
	struct dx_entry *at, *entries, *p, *q, *m;
	struct dx_root *root;
	struct buffer_head *bh;
	struct dx_frame *frame = frame_in;
	u32 hash;

	frame->bh = NULL;
	if (!(bh = ext4_bread(NULL, dir, 0, 0, err))) {
		if (*err == 0)
			*err = ERR_BAD_DX_DIR;
		goto fail;
	}
	root = (struct dx_root *) bh->b_data;
	if (root->info.hash_version != DX_HASH_TEA &&
	    root->info.hash_version != DX_HASH_HALF_MD4 &&
	    root->info.hash_version != DX_HASH_LEGACY) {
		ext4_warning(dir->i_sb, "Unrecognised inode hash code %d",
			     root->info.hash_version);
		brelse(bh);
		*err = ERR_BAD_DX_DIR;
		goto fail;
	}
	hinfo->hash_version = root->info.hash_version;
	if (hinfo->hash_version <= DX_HASH_TEA)
		hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
	hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
	if (d_name)
		ext4fs_dirhash(d_name->name, d_name->len, hinfo);
	hash = hinfo->hash;

	if (root->info.unused_flags & 1) {
		ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x",
			     root->info.unused_flags);
		brelse(bh);
		*err = ERR_BAD_DX_DIR;
		goto fail;
	}

	if ((indirect = root->info.indirect_levels) > 1) {
		ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x",
			     root->info.indirect_levels);
		brelse(bh);
		*err = ERR_BAD_DX_DIR;
		goto fail;
	}

	if (!buffer_verified(bh) &&
	    !ext4_dx_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data)) {
		ext4_warning(dir->i_sb, "Root failed checksum");
		brelse(bh);
		*err = ERR_BAD_DX_DIR;
		goto fail;
	}
	set_buffer_verified(bh);

	entries = (struct dx_entry *) (((char *)&root->info) +
				       root->info.info_length);

	if (dx_get_limit(entries) != dx_root_limit(dir,
						   root->info.info_length)) {
		ext4_warning(dir->i_sb, "dx entry: limit != root limit");
		brelse(bh);
		*err = ERR_BAD_DX_DIR;
		goto fail;
	}

	dxtrace(printk("Look up %x", hash));
	while (1)
	{
		count = dx_get_count(entries);
		if (!count || count > dx_get_limit(entries)) {
			ext4_warning(dir->i_sb,
				     "dx entry: no count or count > limit");
			brelse(bh);
			*err = ERR_BAD_DX_DIR;
			goto fail2;
		}

		p = entries + 1;
		q = entries + count - 1;
		while (p <= q)
		{
			m = p + (q - p)/2;
			dxtrace(printk("."));
			if (dx_get_hash(m) > hash)
				q = m - 1;
			else
				p = m + 1;
		}

		if (0) // linear search cross check
		{
			unsigned n = count - 1;
			at = entries;
			while (n--)
			{
				dxtrace(printk(","));
				if (dx_get_hash(++at) > hash)
				{
					at--;
					break;
				}
			}
			assert (at == p - 1);
		}

		at = p - 1;
		dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
		frame->bh = bh;
		frame->entries = entries;
		frame->at = at;
		if (!indirect--) return frame;
		if (!(bh = ext4_bread(NULL, dir, dx_get_block(at), 0, err))) {
			if (!(*err))
				*err = ERR_BAD_DX_DIR;
			goto fail2;
		}
		at = entries = ((struct dx_node *) bh->b_data)->entries;

		if (!buffer_verified(bh) &&
		    !ext4_dx_csum_verify(dir,
					 (struct ext4_dir_entry *)bh->b_data)) {
			ext4_warning(dir->i_sb, "Node failed checksum");
			brelse(bh);
			*err = ERR_BAD_DX_DIR;
			goto fail;
		}
		set_buffer_verified(bh);

		if (dx_get_limit(entries) != dx_node_limit (dir)) {
			ext4_warning(dir->i_sb,
				     "dx entry: limit != node limit");
			brelse(bh);
			*err = ERR_BAD_DX_DIR;
			goto fail2;
		}
		frame++;
		frame->bh = NULL;
	}
fail2:
	while (frame >= frame_in) {
		brelse(frame->bh);
		frame--;
	}
fail:
	if (*err == ERR_BAD_DX_DIR)
		ext4_warning(dir->i_sb,
			     "Corrupt dir inode %lu, running e2fsck is "
			     "recommended.", dir->i_ino);
	return NULL;
}

Project: linux
File: namei.c

static void dx_release (struct dx_frame *frames)
{
	if (frames[0].bh == NULL)
		return;

	if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
		brelse(frames[1].bh);
	brelse(frames[0].bh);
}

Project: linux
File: namei.c

static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
{
	unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
		EXT4_DIR_REC_LEN(2) - infosize;

	if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
		entry_space -= sizeof(struct dx_tail);
	return entry_space / sizeof(struct dx_entry);
}

Project: linux
File: namei.c

static inline void dx_set_count(struct dx_entry *entries, unsigned value)
{
	((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
}

Project: linux
File: namei.c

static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
{
	entry->hash = cpu_to_le32(value);
}

Project: linux
File: namei.c

struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
			     struct dx_entry *entries, int levels)
{
	unsigned blocksize = dir->i_sb->s_blocksize;
	unsigned count = dx_get_count(entries), names = 0, space = 0, i;
	unsigned bcount = 0;
	struct buffer_head *bh;
	int err;
	printk("%i indexed blocks...\n", count);
	for (i = 0; i < count; i++, entries++)
	{
		ext4_lblk_t block = dx_get_block(entries);
		ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
		u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
		struct stats stats;
		printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
		if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
		stats = levels?
		   dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
		   dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
		names += stats.names;
		space += stats.space;
		bcount += stats.bcount;
		brelse(bh);
	}
	if (bcount)
		printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
		       levels ? "" : "   ", names, space/bcount,
		       (space/bcount)*100/blocksize);
	return (struct stats) { names, space, bcount};
}

Project: linux
File: namei.c

static void dx_show_index(char * label, struct dx_entry *entries)
{
	int i, n = dx_get_count (entries);
	printk(KERN_DEBUG "%s index ", label);
	for (i = 0; i < n; i++) {
		printk("%x->%lu ", i ? dx_get_hash(entries + i) :
				0, (unsigned long)dx_get_block(entries + i));
	}
	printk("\n");
}

Project: linux
File: namei.c

static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
				 int size, int show_names)
{
	unsigned names = 0, space = 0;
	char *base = (char *) de;
	struct dx_hash_info h = *hinfo;

	printk("names: ");
	while ((char *) de < base + size)
	{
		if (de->inode)
		{
			if (show_names)
			{
				int len = de->name_len;
				char *name = de->name;
				while (len--) printk("%c", *name++);
				ext4fs_dirhash(de->name, de->name_len, &h);
				printk(":%x.%u ", h.hash,
				       (unsigned) ((char *) de - base));
			}
			space += EXT4_DIR_REC_LEN(de->name_len);
			names++;
		}
		de = ext4_next_entry(de, size);
	}
	printk("(%i)\n", names);
	return (struct stats) { names, space, 1 };
}

Project: linux
File: namei.c

static void dx_sort_map (struct dx_map_entry *map, unsigned count)
{
	struct dx_map_entry *p, *q, *top = map + count - 1;
	int more;
	/* Combsort until bubble sort doesn't suck */
	while (count > 2) {
		count = count*10/13;
		if (count - 9 < 2) /* 9, 10 -> 11 */
			count = 11;
		for (p = top, q = p - count; q >= map; p--, q--)
			if (p->hash < q->hash)
				swap(*p, *q);
	}
	/* Garden variety bubble sort */
	do {
		more = 0;
		q = top;
		while (q-- > map) {
			if (q[1].hash >= q[0].hash)
				continue;
			swap(*(q+1), *q);
			more = 1;
		}
	} while(more);
}

Project: linux
File: namei.c

static int empty_dir(struct inode *inode)
{
	unsigned int offset;
	struct buffer_head *bh;
	struct ext4_dir_entry_2 *de, *de1;
	struct super_block *sb;
	int err = 0;

	if (ext4_has_inline_data(inode)) {
		int has_inline_data = 1;

		err = empty_inline_dir(inode, &has_inline_data);
		if (has_inline_data)
			return err;
	}

	sb = inode->i_sb;
	if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
	    !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
		if (err)
			EXT4_ERROR_INODE(inode,
				"error %d reading directory lblock 0", err);
		else
			ext4_warning(inode->i_sb,
				     "bad directory (dir #%lu) - no data block",
				     inode->i_ino);
		return 1;
	}
	if (!buffer_verified(bh) &&
	    !ext4_dirent_csum_verify(inode,
			(struct ext4_dir_entry *)bh->b_data)) {
		EXT4_ERROR_INODE(inode, "checksum error reading directory "
				 "lblock 0");
		return -EIO;
	}
	set_buffer_verified(bh);
	de = (struct ext4_dir_entry_2 *) bh->b_data;
	de1 = ext4_next_entry(de, sb->s_blocksize);
	if (le32_to_cpu(de->inode) != inode->i_ino ||
			!le32_to_cpu(de1->inode) ||
			strcmp(".", de->name) ||
			strcmp("..", de1->name)) {
		ext4_warning(inode->i_sb,
			     "bad directory (dir #%lu) - no `.' or `..'",
			     inode->i_ino);
		brelse(bh);
		return 1;
	}
	offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
		 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
	de = ext4_next_entry(de1, sb->s_blocksize);
	while (offset < inode->i_size) {
		if (!bh ||
		    (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
			unsigned int lblock;
			err = 0;
			brelse(bh);
			lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
			bh = ext4_bread(NULL, inode, lblock, 0, &err);
			if (!bh) {
				if (err)
					EXT4_ERROR_INODE(inode,
						"error %d reading directory "
						"lblock %u", err, lblock);
				else
					ext4_warning(inode->i_sb,
						"bad directory (dir #%lu) - no data block",
						inode->i_ino);

				offset += sb->s_blocksize;
				continue;
			}
			if (!buffer_verified(bh) &&
			    !ext4_dirent_csum_verify(inode,
					(struct ext4_dir_entry *)bh->b_data)) {
				EXT4_ERROR_INODE(inode, "checksum error "
						 "reading directory lblock 0");
				return -EIO;
			}
			set_buffer_verified(bh);
			de = (struct ext4_dir_entry_2 *) bh->b_data;
		}
		if (ext4_check_dir_entry(inode, NULL, de, bh,
					 bh->b_data, bh->b_size, offset)) {
			de = (struct ext4_dir_entry_2 *)(bh->b_data +
							 sb->s_blocksize);
			offset = (offset | (sb->s_blocksize - 1)) + 1;
			continue;
		}
		if (le32_to_cpu(de->inode)) {
			brelse(bh);
			return 0;
		}
		offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
		de = ext4_next_entry(de, sb->s_blocksize);
	}
	brelse(bh);
	return 1;
}

Project: linux
File: namei.c

static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
			  struct inode *inode)
{
	struct inode *dir = dentry->d_parent->d_inode;
	struct buffer_head *bh;
	struct ext4_dir_entry_2 *de;
	struct ext4_dir_entry_tail *t;
	struct super_block *sb;
	int	retval;
	int	dx_fallback=0;
	unsigned blocksize;
	ext4_lblk_t block, blocks;
	int	csum_size = 0;

	if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
		csum_size = sizeof(struct ext4_dir_entry_tail);

	sb = dir->i_sb;
	blocksize = sb->s_blocksize;
	if (!dentry->d_name.len)
		return -EINVAL;

	if (ext4_has_inline_data(dir)) {
		retval = ext4_try_add_inline_entry(handle, dentry, inode);
		if (retval < 0)
			return retval;
		if (retval == 1) {
			retval = 0;
			return retval;
		}
	}

	if (is_dx(dir)) {
		retval = ext4_dx_add_entry(handle, dentry, inode);
		if (!retval || (retval != ERR_BAD_DX_DIR))
			return retval;
		ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
		dx_fallback++;
		ext4_mark_inode_dirty(handle, dir);
	}
	blocks = dir->i_size >> sb->s_blocksize_bits;
	for (block = 0; block < blocks; block++) {
		if (!(bh = ext4_bread(handle, dir, block, 0, &retval))) {
			if (!retval) {
				retval = -EIO;
				ext4_error(inode->i_sb,
					   "Directory hole detected on inode %lu\n",
					   inode->i_ino);
			}
			return retval;
		}
		if (!buffer_verified(bh) &&
		    !ext4_dirent_csum_verify(dir,
				(struct ext4_dir_entry *)bh->b_data))
			return -EIO;
		set_buffer_verified(bh);
		retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
		if (retval != -ENOSPC) {
			brelse(bh);
			return retval;
		}

		if (blocks == 1 && !dx_fallback &&
		    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
			return make_indexed_dir(handle, dentry, inode, bh);
		brelse(bh);
	}
	bh = ext4_append(handle, dir, &block, &retval);
	if (!bh)
		return retval;
	de = (struct ext4_dir_entry_2 *) bh->b_data;
	de->inode = 0;
	de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);

	if (csum_size) {
		t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
		initialize_dirent_tail(t, blocksize);
	}

	retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
	brelse(bh);
	if (retval == 0)
		ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
	return retval;
}

Project: linux
File: namei.c

static int ext4_add_nondir(handle_t *handle,
		struct dentry *dentry, struct inode *inode)
{
	int err = ext4_add_entry(handle, dentry, inode);
	if (!err) {
		ext4_mark_inode_dirty(handle, inode);
		unlock_new_inode(inode);
		d_instantiate(dentry, inode);
		return 0;
	}
	drop_nlink(inode);
	unlock_new_inode(inode);
	iput(inode);
	return err;
}

Project: linux
File: namei.c

static struct buffer_head *ext4_append(handle_t *handle,
					struct inode *inode,
					ext4_lblk_t *block, int *err)
{
	struct buffer_head *bh;

	if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
		     ((inode->i_size >> 10) >=
		      EXT4_SB(inode->i_sb)->s_max_dir_size_kb))) {
		*err = -ENOSPC;
		return NULL;
	}

	*block = inode->i_size >> inode->i_sb->s_blocksize_bits;

	bh = ext4_bread(handle, inode, *block, 1, err);
	if (bh) {
		inode->i_size += inode->i_sb->s_blocksize;
		EXT4_I(inode)->i_disksize = inode->i_size;
		*err = ext4_journal_get_write_access(handle, bh);
		if (*err) {
			brelse(bh);
			bh = NULL;
		}
	}
	if (!bh && !(*err)) {
		*err = -EIO;
		ext4_error(inode->i_sb,
			   "Directory hole detected on inode %lu\n",
			   inode->i_ino);
	}
	return bh;
}

Project: linux
File: namei.c

static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
		       bool excl)
{
	handle_t *handle;
	struct inode *inode;
	int err, retries = 0;

	dquot_initialize(dir);

retry:
	handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
					EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
					EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
	if (IS_ERR(handle))
		return PTR_ERR(handle);

	if (IS_DIRSYNC(dir))
		ext4_handle_sync(handle);

	inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0, NULL);
	err = PTR_ERR(inode);
	if (!IS_ERR(inode)) {
		inode->i_op = &ext4_file_inode_operations;
		inode->i_fop = &ext4_file_operations;
		ext4_set_aops(inode);
		err = ext4_add_nondir(handle, dentry, inode);
	}
	ext4_journal_stop(handle);
	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
		goto retry;
	return err;
}

Project: linux
File: namei.c

static void ext4_dec_count(handle_t *handle, struct inode *inode)
{
	if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
		drop_nlink(inode);
}

Project: linux
File: namei.c

static int ext4_delete_entry(handle_t *handle,
			     struct inode *dir,
			     struct ext4_dir_entry_2 *de_del,
			     struct buffer_head *bh)
{
	int err, csum_size = 0;

	if (ext4_has_inline_data(dir)) {
		int has_inline_data = 1;
		err = ext4_delete_inline_entry(handle, dir, de_del, bh,
					       &has_inline_data);
		if (has_inline_data)
			return err;
	}

	if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
		csum_size = sizeof(struct ext4_dir_entry_tail);

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

	err = ext4_generic_delete_entry(handle, dir, de_del,
					bh, bh->b_data,
					dir->i_sb->s_blocksize, csum_size);
	if (err)
		goto out;

	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
	err = ext4_handle_dirty_dirent_node(handle, dir, bh);
	if (unlikely(err))
		goto out;

	return 0;
out:
	if (err != -ENOENT)
		ext4_std_error(dir->i_sb, err);
	return err;
}

Project: linux
File: namei.c

static __le32 ext4_dirent_csum(struct inode *inode,
			       struct ext4_dir_entry *dirent, int size)
{
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
	struct ext4_inode_info *ei = EXT4_I(inode);
	__u32 csum;

	csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
	return cpu_to_le32(csum);
}

Project: linux
File: namei.c

static void ext4_dirent_csum_set(struct inode *inode,
				 struct ext4_dir_entry *dirent)
{
	struct ext4_dir_entry_tail *t;

	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
		return;

	t = get_dirent_tail(inode, dirent);
	if (!t) {
		warn_no_space_for_csum(inode);
		return;
	}

	t->det_checksum = ext4_dirent_csum(inode, dirent,
					   (void *)t - (void *)dirent);
}

Project: linux
File: namei.c

int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
{
	struct ext4_dir_entry_tail *t;

	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
		return 1;

	t = get_dirent_tail(inode, dirent);
	if (!t) {
		warn_no_space_for_csum(inode);
		return 0;
	}

	if (t->det_checksum != ext4_dirent_csum(inode, dirent,
						(void *)t - (void *)dirent))
		return 0;

	return 1;
}

Project: linux
File: namei.c

static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
			   int count_offset, int count, struct dx_tail *t)
{
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
	struct ext4_inode_info *ei = EXT4_I(inode);
	__u32 csum, old_csum;
	int size;

	size = count_offset + (count * sizeof(struct dx_entry));
	old_csum = t->dt_checksum;
	t->dt_checksum = 0;
	csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
	csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
	t->dt_checksum = old_csum;

	return cpu_to_le32(csum);
}

Project: linux
File: namei.c

static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
{
	struct dx_countlimit *c;
	struct dx_tail *t;
	int count_offset, limit, count;

	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
		return;

	c = get_dx_countlimit(inode, dirent, &count_offset);
	if (!c) {
		EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
		return;
	}
	limit = le16_to_cpu(c->limit);
	count = le16_to_cpu(c->count);
	if (count_offset + (limit * sizeof(struct dx_entry)) >
	    EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
		warn_no_space_for_csum(inode);
		return;
	}
	t = (struct dx_tail *)(((struct dx_entry *)c) + limit);

	t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
}

Project: linux
File: namei.c

static int ext4_dx_csum_verify(struct inode *inode,
			       struct ext4_dir_entry *dirent)
{
	struct dx_countlimit *c;
	struct dx_tail *t;
	int count_offset, limit, count;

	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
		return 1;

	c = get_dx_countlimit(inode, dirent, &count_offset);
	if (!c) {
		EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
		return 1;
	}
	limit = le16_to_cpu(c->limit);
	count = le16_to_cpu(c->count);
	if (count_offset + (limit * sizeof(struct dx_entry)) >
	    EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
		warn_no_space_for_csum(inode);
		return 1;
	}
	t = (struct dx_tail *)(((struct dx_entry *)c) + limit);

	if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
					    count, t))
		return 0;
	return 1;
}

Project: linux
File: namei.c

static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
		       struct ext4_dir_entry_2 **res_dir, int *err)
{
	struct super_block * sb = dir->i_sb;
	struct dx_hash_info	hinfo;
	struct dx_frame frames[2], *frame;
	struct buffer_head *bh;
	ext4_lblk_t block;
	int retval;

	if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
		return NULL;
	do {
		block = dx_get_block(frame->at);
		if (!(bh = ext4_bread(NULL, dir, block, 0, err))) {
			if (!(*err)) {
				*err = -EIO;
				ext4_error(dir->i_sb,
					   "Directory hole detected on inode %lu\n",
					   dir->i_ino);
			}
			goto errout;
		}

		if (!buffer_verified(bh) &&
		    !ext4_dirent_csum_verify(dir,
				(struct ext4_dir_entry *)bh->b_data)) {
			EXT4_ERROR_INODE(dir, "checksumming directory "
					 "block %lu", (unsigned long)block);
			brelse(bh);
			*err = -EIO;
			goto errout;
		}
		set_buffer_verified(bh);
		retval = search_dirblock(bh, dir, d_name,
					 block << EXT4_BLOCK_SIZE_BITS(sb),
					 res_dir);
		if (retval == 1) { 	/* Success! */
			dx_release(frames);
			return bh;
		}
		brelse(bh);
		if (retval == -1) {
			*err = ERR_BAD_DX_DIR;
			goto errout;
		}

		/* Check to see if we should continue to search */
		retval = ext4_htree_next_block(dir, hinfo.hash, frame,
					       frames, NULL);
		if (retval < 0) {
			ext4_warning(sb,
			     "error reading index page in directory #%lu",
			     dir->i_ino);
			*err = retval;
			goto errout;
		}
	} while (retval == 1);

	*err = -ENOENT;
errout:
	dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
	dx_release (frames);
	return NULL;
}

Project: linux
File: namei.c

int ext4_find_dest_de(struct inode *dir, struct inode *inode,
		      struct buffer_head *bh,
		      void *buf, int buf_size,
		      const char *name, int namelen,
		      struct ext4_dir_entry_2 **dest_de)
{
	struct ext4_dir_entry_2 *de;
	unsigned short reclen = EXT4_DIR_REC_LEN(namelen);
	int nlen, rlen;
	unsigned int offset = 0;
	char *top;

	de = (struct ext4_dir_entry_2 *)buf;
	top = buf + buf_size - reclen;
	while ((char *) de <= top) {
		if (ext4_check_dir_entry(dir, NULL, de, bh,
					 buf, buf_size, offset))
			return -EIO;
		if (ext4_match(namelen, name, de))
			return -EEXIST;
		nlen = EXT4_DIR_REC_LEN(de->name_len);
		rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
		if ((de->inode ? rlen - nlen : rlen) >= reclen)
			break;
		de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
		offset += rlen;
	}
	if ((char *) de > top)
		return -ENOSPC;

	*dest_de = de;
	return 0;
}

Project: linux
File: namei.c

static struct buffer_head * ext4_find_entry (struct inode *dir,
					const struct qstr *d_name,
					struct ext4_dir_entry_2 **res_dir,
					int *inlined)
{
	struct super_block *sb;
	struct buffer_head *bh_use[NAMEI_RA_SIZE];
	struct buffer_head *bh, *ret = NULL;
	ext4_lblk_t start, block, b;
	const u8 *name = d_name->name;
	int ra_max = 0;		/* Number of bh's in the readahead
				   buffer, bh_use[] */
	int ra_ptr = 0;		/* Current index into readahead
				   buffer */
	int num = 0;
	ext4_lblk_t  nblocks;
	int i, err;
	int namelen;

	*res_dir = NULL;
	sb = dir->i_sb;
	namelen = d_name->len;
	if (namelen > EXT4_NAME_LEN)
		return NULL;

	if (ext4_has_inline_data(dir)) {
		int has_inline_data = 1;
		ret = ext4_find_inline_entry(dir, d_name, res_dir,
					     &has_inline_data);
		if (has_inline_data) {
			if (inlined)
				*inlined = 1;
			return ret;
		}
	}

	if ((namelen <= 2) && (name[0] == '.') &&
	    (name[1] == '.' || name[1] == '\0')) {
		/*
		 * "." or ".." will only be in the first block
		 * NFS may look up ".."; "." should be handled by the VFS
		 */
		block = start = 0;
		nblocks = 1;
		goto restart;
	}
	if (is_dx(dir)) {
		bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
		/*
		 * On success, or if the error was file not found,
		 * return.  Otherwise, fall back to doing a search the
		 * old fashioned way.
		 */
		if (bh || (err != ERR_BAD_DX_DIR))
			return bh;
		dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
			       "falling back\n"));
	}
	nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
	start = EXT4_I(dir)->i_dir_start_lookup;
	if (start >= nblocks)
		start = 0;
	block = start;
restart:
	do {
		/*
		 * We deal with the read-ahead logic here.
		 */
		if (ra_ptr >= ra_max) {
			/* Refill the readahead buffer */
			ra_ptr = 0;
			b = block;
			for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
				/*
				 * Terminate if we reach the end of the
				 * directory and must wrap, or if our
				 * search has finished at this block.
				 */
				if (b >= nblocks || (num && block == start)) {
					bh_use[ra_max] = NULL;
					break;
				}
				num++;
				bh = ext4_getblk(NULL, dir, b++, 0, &err);
				bh_use[ra_max] = bh;
				if (bh)
					ll_rw_block(READ | REQ_META | REQ_PRIO,
						    1, &bh);
			}
		}
		if ((bh = bh_use[ra_ptr++]) == NULL)
			goto next;
		wait_on_buffer(bh);
		if (!buffer_uptodate(bh)) {
			/* read error, skip block & hope for the best */
			EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
					 (unsigned long) block);
			brelse(bh);
			goto next;
		}
		if (!buffer_verified(bh) &&
		    !is_dx_internal_node(dir, block,
					 (struct ext4_dir_entry *)bh->b_data) &&
		    !ext4_dirent_csum_verify(dir,
				(struct ext4_dir_entry *)bh->b_data)) {
			EXT4_ERROR_INODE(dir, "checksumming directory "
					 "block %lu", (unsigned long)block);
			brelse(bh);
			goto next;
		}
		set_buffer_verified(bh);
		i = search_dirblock(bh, dir, d_name,
			    block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
		if (i == 1) {
			EXT4_I(dir)->i_dir_start_lookup = block;
			ret = bh;
			goto cleanup_and_exit;
		} else {
			brelse(bh);
			if (i < 0)
				goto cleanup_and_exit;
		}
	next:
		if (++block >= nblocks)
			block = 0;
	} while (block != start);

	/*
	 * If the directory has grown while we were searching, then
	 * search the last part of the directory before giving up.
	 */
	block = nblocks;
	nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
	if (block < nblocks) {
		start = 0;
		goto restart;
	}

cleanup_and_exit:
	/* Clean up the read-ahead blocks */
	for (; ra_ptr < ra_max; ra_ptr++)
		brelse(bh_use[ra_ptr]);
	return ret;
}

Project: linux
File: namei.c

int ext4_generic_delete_entry(handle_t *handle,
			      struct inode *dir,
			      struct ext4_dir_entry_2 *de_del,
			      struct buffer_head *bh,
			      void *entry_buf,
			      int buf_size,
			      int csum_size)
{
	struct ext4_dir_entry_2 *de, *pde;
	unsigned int blocksize = dir->i_sb->s_blocksize;
	int i;

	i = 0;
	pde = NULL;
	de = (struct ext4_dir_entry_2 *)entry_buf;
	while (i < buf_size - csum_size) {
		if (ext4_check_dir_entry(dir, NULL, de, bh,
					 bh->b_data, bh->b_size, i))
			return -EIO;
		if (de == de_del)  {
			if (pde)
				pde->rec_len = ext4_rec_len_to_disk(
					ext4_rec_len_from_disk(pde->rec_len,
							       blocksize) +
					ext4_rec_len_from_disk(de->rec_len,
							       blocksize),
					blocksize);
			else
				de->inode = 0;
			dir->i_version++;
			return 0;
		}
		i += ext4_rec_len_from_disk(de->rec_len, blocksize);
		pde = de;
		de = ext4_next_entry(de, blocksize);
	}
	return -ENOENT;
}

Project: linux
File: namei.c

struct dentry *ext4_get_parent(struct dentry *child)
{
	__u32 ino;
	static const struct qstr dotdot = QSTR_INIT("..", 2);
	struct ext4_dir_entry_2 * de;
	struct buffer_head *bh;

	bh = ext4_find_entry(child->d_inode, &dotdot, &de, NULL);
	if (!bh)
		return ERR_PTR(-ENOENT);
	ino = le32_to_cpu(de->inode);
	brelse(bh);

	if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
		EXT4_ERROR_INODE(child->d_inode,
				 "bad parent inode number: %u", ino);
		return ERR_PTR(-EIO);
	}

	return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
}

Project: linux
File: namei.c

int ext4_handle_dirty_dirent_node(handle_t *handle,
				  struct inode *inode,
				  struct buffer_head *bh)
{
	ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
	return ext4_handle_dirty_metadata(handle, inode, bh);
}

Project: linux
File: namei.c

static inline int ext4_handle_dirty_dx_node(handle_t *handle,
					    struct inode *inode,
					    struct buffer_head *bh)
{
	ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
	return ext4_handle_dirty_metadata(handle, inode, bh);
}

Project: linux
File: namei.c

int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
			 __u32 start_minor_hash, __u32 *next_hash)
{
	struct dx_hash_info hinfo;
	struct ext4_dir_entry_2 *de;
	struct dx_frame frames[2], *frame;
	struct inode *dir;
	ext4_lblk_t block;
	int count = 0;
	int ret, err;
	__u32 hashval;

	dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
		       start_hash, start_minor_hash));
	dir = dir_file->f_path.dentry->d_inode;
	if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
		hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
		if (hinfo.hash_version <= DX_HASH_TEA)
			hinfo.hash_version +=
				EXT4_SB(dir->i_sb)->s_hash_unsigned;
		hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
		count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
					       start_hash, start_minor_hash);
		*next_hash = ~0;
		return count;
	}
	hinfo.hash = start_hash;
	hinfo.minor_hash = 0;
	frame = dx_probe(NULL, dir, &hinfo, frames, &err);
	if (!frame)
		return err;

	/* Add '.' and '..' from the htree header */
	if (!start_hash && !start_minor_hash) {
		de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
		if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
			goto errout;
		count++;
	}
	if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
		de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
		de = ext4_next_entry(de, dir->i_sb->s_blocksize);
		if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
			goto errout;
		count++;
	}

	while (1) {
		block = dx_get_block(frame->at);
		ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
					     start_hash, start_minor_hash);
		if (ret < 0) {
			err = ret;
			goto errout;
		}
		count += ret;
		hashval = ~0;
		ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
					    frame, frames, &hashval);
		*next_hash = hashval;
		if (ret < 0) {
			err = ret;
			goto errout;
		}
		/*
		 * Stop if:  (a) there are no more entries, or
		 * (b) we have inserted at least one entry and the
		 * next hash value is not a continuation
		 */
		if ((ret == 0) ||
		    (count && ((hashval & 1) == 0)))
			break;
	}
	dx_release(frames);
	dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
		       "next hash: %x\n", count, *next_hash));
	return count;
errout:
	dx_release(frames);
	return (err);
}

Project: linux
File: namei.c

static int ext4_htree_next_block(struct inode *dir, __u32 hash,
				 struct dx_frame *frame,
				 struct dx_frame *frames,
				 __u32 *start_hash)
{
	struct dx_frame *p;
	struct buffer_head *bh;
	int err, num_frames = 0;
	__u32 bhash;

	p = frame;
	/*
	 * Find the next leaf page by incrementing the frame pointer.
	 * If we run out of entries in the interior node, loop around and
	 * increment pointer in the parent node.  When we break out of
	 * this loop, num_frames indicates the number of interior
	 * nodes need to be read.
	 */
	while (1) {
		if (++(p->at) < p->entries + dx_get_count(p->entries))
			break;
		if (p == frames)
			return 0;
		num_frames++;
		p--;
	}

	/*
	 * If the hash is 1, then continue only if the next page has a
	 * continuation hash of any value.  This is used for readdir
	 * handling.  Otherwise, check to see if the hash matches the
	 * desired contiuation hash.  If it doesn't, return since
	 * there's no point to read in the successive index pages.
	 */
	bhash = dx_get_hash(p->at);
	if (start_hash)
		*start_hash = bhash;
	if ((hash & 1) == 0) {
		if ((bhash & ~1) != hash)
			return 0;
	}
	/*
	 * If the hash is HASH_NB_ALWAYS, we always go to the next
	 * block so no check is necessary
	 */
	while (num_frames--) {
		if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
				      0, &err))) {
			if (!err) {
				ext4_error(dir->i_sb,
					   "Directory hole detected on inode %lu\n",
					   dir->i_ino);
				return -EIO;
			}
			return err; /* Failure */
		}

		if (!buffer_verified(bh) &&
		    !ext4_dx_csum_verify(dir,
					 (struct ext4_dir_entry *)bh->b_data)) {
			ext4_warning(dir->i_sb, "Node failed checksum");
			return -EIO;
		}
		set_buffer_verified(bh);

		p++;
		brelse(p->bh);
		p->bh = bh;
		p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
	}
	return 1;
}

Project: linux
File: namei.c

static void ext4_inc_count(handle_t *handle, struct inode *inode)
{
	inc_nlink(inode);
	if (is_dx(inode) && inode->i_nlink > 1) {
		/* limit is 16-bit i_links_count */
		if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
			set_nlink(inode, 1);
			EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
					      EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
		}
	}
}

Project: linux
File: namei.c

struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
			  struct ext4_dir_entry_2 *de,
			  int blocksize, int csum_size,
			  unsigned int parent_ino, int dotdot_real_len)
{
	de->inode = cpu_to_le32(inode->i_ino);
	de->name_len = 1;
	de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
					   blocksize);
	strcpy(de->name, ".");
	ext4_set_de_type(inode->i_sb, de, S_IFDIR);

	de = ext4_next_entry(de, blocksize);
	de->inode = cpu_to_le32(parent_ino);
	de->name_len = 2;
	if (!dotdot_real_len)
		de->rec_len = ext4_rec_len_to_disk(blocksize -
					(csum_size + EXT4_DIR_REC_LEN(1)),
					blocksize);
	else
		de->rec_len = ext4_rec_len_to_disk(
				EXT4_DIR_REC_LEN(de->name_len), blocksize);
	strcpy(de->name, "..");
	ext4_set_de_type(inode->i_sb, de, S_IFDIR);

	return ext4_next_entry(de, blocksize);
}

Project: linux
File: namei.c

static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
			     struct inode *inode)
{
	struct buffer_head *dir_block = NULL;
	struct ext4_dir_entry_2 *de;
	struct ext4_dir_entry_tail *t;
	unsigned int blocksize = dir->i_sb->s_blocksize;
	int csum_size = 0;
	int err;

	if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
		csum_size = sizeof(struct ext4_dir_entry_tail);

	if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
		err = ext4_try_create_inline_dir(handle, dir, inode);
		if (err < 0 && err != -ENOSPC)
			goto out;
		if (!err)
			goto out;
	}

	inode->i_size = EXT4_I(inode)->i_disksize = blocksize;
	dir_block = ext4_bread(handle, inode, 0, 1, &err);
	if (!(dir_block = ext4_bread(handle, inode, 0, 1, &err))) {
		if (!err) {
			err = -EIO;
			ext4_error(inode->i_sb,
				   "Directory hole detected on inode %lu\n",
				   inode->i_ino);
		}
		goto out;
	}
	BUFFER_TRACE(dir_block, "get_write_access");
	err = ext4_journal_get_write_access(handle, dir_block);
	if (err)
		goto out;
	de = (struct ext4_dir_entry_2 *)dir_block->b_data;
	ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
	set_nlink(inode, 2);
	if (csum_size) {
		t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
		initialize_dirent_tail(t, blocksize);
	}

	BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
	err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
	if (err)
		goto out;
	set_buffer_verified(dir_block);
out:
	brelse(dir_block);
	return err;
}

Project: linux
File: namei.c

void ext4_insert_dentry(struct inode *inode,
			struct ext4_dir_entry_2 *de,
			int buf_size,
			const char *name, int namelen)
{

	int nlen, rlen;

	nlen = EXT4_DIR_REC_LEN(de->name_len);
	rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
	if (de->inode) {
		struct ext4_dir_entry_2 *de1 =
				(struct ext4_dir_entry_2 *)((char *)de + nlen);
		de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
		de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
		de = de1;
	}
	de->file_type = EXT4_FT_UNKNOWN;
	de->inode = cpu_to_le32(inode->i_ino);
	ext4_set_de_type(inode->i_sb, de, inode->i_mode);
	de->name_len = namelen;
	memcpy(de->name, name, namelen);
}

Project: linux
File: namei.c

static int ext4_link(struct dentry *old_dentry,
		     struct inode *dir, struct dentry *dentry)
{
	handle_t *handle;
	struct inode *inode = old_dentry->d_inode;
	int err, retries = 0;

	if (inode->i_nlink >= EXT4_LINK_MAX)
		return -EMLINK;

	dquot_initialize(dir);

retry:
	handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
					EXT4_INDEX_EXTRA_TRANS_BLOCKS);
	if (IS_ERR(handle))
		return PTR_ERR(handle);

	if (IS_DIRSYNC(dir))
		ext4_handle_sync(handle);

	inode->i_ctime = ext4_current_time(inode);
	ext4_inc_count(handle, inode);
	ihold(inode);

	err = ext4_add_entry(handle, dentry, inode);
	if (!err) {
		ext4_mark_inode_dirty(handle, inode);
		d_instantiate(dentry, inode);
	} else {
		drop_nlink(inode);
		iput(inode);
	}
	ext4_journal_stop(handle);
	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
		goto retry;
	return err;
}

Project: linux
File: namei.c

static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
	struct inode *inode;
	struct ext4_dir_entry_2 *de;
	struct buffer_head *bh;

	if (dentry->d_name.len > EXT4_NAME_LEN)
		return ERR_PTR(-ENAMETOOLONG);

	bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
	inode = NULL;
	if (bh) {
		__u32 ino = le32_to_cpu(de->inode);
		brelse(bh);
		if (!ext4_valid_inum(dir->i_sb, ino)) {
			EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
			return ERR_PTR(-EIO);
		}
		if (unlikely(ino == dir->i_ino)) {
			EXT4_ERROR_INODE(dir, "'%.*s' linked to parent dir",
					 dentry->d_name.len,
					 dentry->d_name.name);
			return ERR_PTR(-EIO);
		}
		inode = ext4_iget(dir->i_sb, ino);
		if (inode == ERR_PTR(-ESTALE)) {
			EXT4_ERROR_INODE(dir,
					 "deleted inode referenced: %u",
					 ino);
			return ERR_PTR(-EIO);
		}
	}
	return d_splice_alias(inode, dentry);
}

Project: linux
File: namei.c

static inline int ext4_match (int len, const char * const name,
			      struct ext4_dir_entry_2 * de)
{
	if (len != de->name_len)
		return 0;
	if (!de->inode)
		return 0;
	return !memcmp(name, de->name, len);
}

Project: linux
File: namei.c

static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	handle_t *handle;
	struct inode *inode;
	int err, retries = 0;

	if (EXT4_DIR_LINK_MAX(dir))
		return -EMLINK;

	dquot_initialize(dir);

retry:
	handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
					EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
					EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
	if (IS_ERR(handle))
		return PTR_ERR(handle);

	if (IS_DIRSYNC(dir))
		ext4_handle_sync(handle);

	inode = ext4_new_inode(handle, dir, S_IFDIR | mode,
			       &dentry->d_name, 0, NULL);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_stop;

	inode->i_op = &ext4_dir_inode_operations;
	inode->i_fop = &ext4_dir_operations;
	err = ext4_init_new_dir(handle, dir, inode);
	if (err)
		goto out_clear_inode;
	err = ext4_mark_inode_dirty(handle, inode);
	if (!err)
		err = ext4_add_entry(handle, dentry, inode);
	if (err) {
out_clear_inode:
		clear_nlink(inode);
		unlock_new_inode(inode);
		ext4_mark_inode_dirty(handle, inode);
		iput(inode);
		goto out_stop;
	}
	ext4_inc_count(handle, dir);
	ext4_update_dx_flag(dir);
	err = ext4_mark_inode_dirty(handle, dir);
	if (err)
		goto out_clear_inode;
	unlock_new_inode(inode);
	d_instantiate(dentry, inode);
out_stop:
	ext4_journal_stop(handle);
	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
		goto retry;
	return err;
}

Project: linux
File: namei.c

static int ext4_mknod(struct inode *dir, struct dentry *dentry,
		      umode_t mode, dev_t rdev)
{
	handle_t *handle;
	struct inode *inode;
	int err, retries = 0;

	if (!new_valid_dev(rdev))
		return -EINVAL;

	dquot_initialize(dir);

retry:
	handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
					EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
					EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb));
	if (IS_ERR(handle))
		return PTR_ERR(handle);

	if (IS_DIRSYNC(dir))
		ext4_handle_sync(handle);

	inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0, NULL);
	err = PTR_ERR(inode);
	if (!IS_ERR(inode)) {
		init_special_inode(inode, inode->i_mode, rdev);
		inode->i_op = &ext4_special_inode_operations;
		err = ext4_add_nondir(handle, dentry, inode);
	}
	ext4_journal_stop(handle);
	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
		goto retry;
	return err;
}

Project: linux
File: namei.c

ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
{
	return (struct ext4_dir_entry_2 *)((char *)p +
		ext4_rec_len_from_disk(p->rec_len, blocksize));
}

Project: linux
File: namei.c

int ext4_orphan_add(handle_t *handle, struct inode *inode)
{
	struct super_block *sb = inode->i_sb;
	struct ext4_iloc iloc;
	int err = 0, rc;

	if (!EXT4_SB(sb)->s_journal)
		return 0;

	mutex_lock(&EXT4_SB(sb)->s_orphan_lock);
	if (!list_empty(&EXT4_I(inode)->i_orphan))
		goto out_unlock;

	/*
	 * Orphan handling is only valid for files with data blocks
	 * being truncated, or files being unlinked. Note that we either
	 * hold i_mutex, or the inode can not be referenced from outside,
	 * so i_nlink should not be bumped due to race
	 */
	J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
		  S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);

	BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
	err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
	if (err)
		goto out_unlock;

	err = ext4_reserve_inode_write(handle, inode, &iloc);
	if (err)
		goto out_unlock;
	/*
	 * Due to previous errors inode may be already a part of on-disk
	 * orphan list. If so skip on-disk list modification.
	 */
	if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <=
		(le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)))
			goto mem_insert;

	/* Insert this inode at the head of the on-disk orphan list... */
	NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
	EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
	err = ext4_handle_dirty_super(handle, sb);
	rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
	if (!err)
		err = rc;

	/* Only add to the head of the in-memory list if all the
	 * previous operations succeeded.  If the orphan_add is going to
	 * fail (possibly taking the journal offline), we can't risk
	 * leaving the inode on the orphan list: stray orphan-list
	 * entries can cause panics at unmount time.
	 *
	 * This is safe: on error we're going to ignore the orphan list
	 * anyway on the next recovery. */
mem_insert:
	if (!err)
		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);

	jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
	jbd_debug(4, "orphan inode %lu will point to %d\n",
			inode->i_ino, NEXT_ORPHAN(inode));
out_unlock:
	mutex_unlock(&EXT4_SB(sb)->s_orphan_lock);
	ext4_std_error(inode->i_sb, err);
	return err;
}

Project: linux
File: namei.c

static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
		       struct inode *new_dir, struct dentry *new_dentry)
{
	handle_t *handle;
	struct inode *old_inode, *new_inode;
	struct buffer_head *old_bh, *new_bh, *dir_bh;
	struct ext4_dir_entry_2 *old_de, *new_de;
	int retval, force_da_alloc = 0;
	int inlined = 0, new_inlined = 0;
	struct ext4_dir_entry_2 *parent_de;

	dquot_initialize(old_dir);
	dquot_initialize(new_dir);

	old_bh = new_bh = dir_bh = NULL;

	/* Initialize quotas before so that eventual writes go
	 * in separate transaction */
	if (new_dentry->d_inode)
		dquot_initialize(new_dentry->d_inode);
	handle = ext4_journal_start(old_dir, 2 *
					EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
					EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
	if (IS_ERR(handle))
		return PTR_ERR(handle);

	if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
		ext4_handle_sync(handle);

	old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de, NULL);
	/*
	 *  Check for inode number is _not_ due to possible IO errors.
	 *  We might rmdir the source, keep it as pwd of some process
	 *  and merrily kill the link to whatever was created under the
	 *  same name. Goodbye sticky bit ;-<
	 */
	old_inode = old_dentry->d_inode;
	retval = -ENOENT;
	if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
		goto end_rename;

	new_inode = new_dentry->d_inode;
	new_bh = ext4_find_entry(new_dir, &new_dentry->d_name,
				 &new_de, &new_inlined);
	if (new_bh) {
		if (!new_inode) {
			brelse(new_bh);
			new_bh = NULL;
		}
	}
	if (S_ISDIR(old_inode->i_mode)) {
		if (new_inode) {
			retval = -ENOTEMPTY;
			if (!empty_dir(new_inode))
				goto end_rename;
		}
		retval = -EIO;
		dir_bh = ext4_get_first_dir_block(handle, old_inode,
						  &retval, &parent_de,
						  &inlined);
		if (!dir_bh)
			goto end_rename;
		if (!inlined && !buffer_verified(dir_bh) &&
		    !ext4_dirent_csum_verify(old_inode,
				(struct ext4_dir_entry *)dir_bh->b_data))
			goto end_rename;
		set_buffer_verified(dir_bh);
		if (le32_to_cpu(parent_de->inode) != old_dir->i_ino)
			goto end_rename;
		retval = -EMLINK;
		if (!new_inode && new_dir != old_dir &&
		    EXT4_DIR_LINK_MAX(new_dir))
			goto end_rename;
		BUFFER_TRACE(dir_bh, "get_write_access");
		retval = ext4_journal_get_write_access(handle, dir_bh);
		if (retval)
			goto end_rename;
	}
	if (!new_bh) {
		retval = ext4_add_entry(handle, new_dentry, old_inode);
		if (retval)
			goto end_rename;
	} else {
		BUFFER_TRACE(new_bh, "get write access");
		retval = ext4_journal_get_write_access(handle, new_bh);
		if (retval)
			goto end_rename;
		new_de->inode = cpu_to_le32(old_inode->i_ino);
		if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
					      EXT4_FEATURE_INCOMPAT_FILETYPE))
			new_de->file_type = old_de->file_type;
		new_dir->i_version++;
		new_dir->i_ctime = new_dir->i_mtime =
					ext4_current_time(new_dir);
		ext4_mark_inode_dirty(handle, new_dir);
		BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
		if (!new_inlined) {
			retval = ext4_handle_dirty_dirent_node(handle,
							       new_dir, new_bh);
			if (unlikely(retval)) {
				ext4_std_error(new_dir->i_sb, retval);
				goto end_rename;
			}
		}
		brelse(new_bh);
		new_bh = NULL;
	}

	/*
	 * Like most other Unix systems, set the ctime for inodes on a
	 * rename.
	 */
	old_inode->i_ctime = ext4_current_time(old_inode);
	ext4_mark_inode_dirty(handle, old_inode);

	/*
	 * ok, that's it
	 */
	if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
	    old_de->name_len != old_dentry->d_name.len ||
	    strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
	    (retval = ext4_delete_entry(handle, old_dir,
					old_de, old_bh)) == -ENOENT) {
		/* old_de could have moved from under us during htree split, so
		 * make sure that we are deleting the right entry.  We might
		 * also be pointing to a stale entry in the unused part of
		 * old_bh so just checking inum and the name isn't enough. */
		struct buffer_head *old_bh2;
		struct ext4_dir_entry_2 *old_de2;

		old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name,
					  &old_de2, NULL);
		if (old_bh2) {
			retval = ext4_delete_entry(handle, old_dir,
						   old_de2, old_bh2);
			brelse(old_bh2);
		}
	}
	if (retval) {
		ext4_warning(old_dir->i_sb,
				"Deleting old file (%lu), %d, error=%d",
				old_dir->i_ino, old_dir->i_nlink, retval);
	}

	if (new_inode) {
		ext4_dec_count(handle, new_inode);
		new_inode->i_ctime = ext4_current_time(new_inode);
	}
	old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
	ext4_update_dx_flag(old_dir);
	if (dir_bh) {
		parent_de->inode = cpu_to_le32(new_dir->i_ino);
		BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
		if (!inlined) {
			if (is_dx(old_inode)) {
				retval = ext4_handle_dirty_dx_node(handle,
								   old_inode,
								   dir_bh);
			} else {
				retval = ext4_handle_dirty_dirent_node(handle,
							old_inode, dir_bh);
			}
		} else {
			retval = ext4_mark_inode_dirty(handle, old_inode);
		}
		if (retval) {
			ext4_std_error(old_dir->i_sb, retval);
			goto end_rename;
		}
		ext4_dec_count(handle, old_dir);
		if (new_inode) {
			/* checked empty_dir above, can't have another parent,
			 * ext4_dec_count() won't work for many-linked dirs */
			clear_nlink(new_inode);
		} else {
			ext4_inc_count(handle, new_dir);
			ext4_update_dx_flag(new_dir);
			ext4_mark_inode_dirty(handle, new_dir);
		}
	}
	ext4_mark_inode_dirty(handle, old_dir);
	if (new_inode) {
		ext4_mark_inode_dirty(handle, new_inode);
		if (!new_inode->i_nlink)
			ext4_orphan_add(handle, new_inode);
		if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
			force_da_alloc = 1;
	}
	retval = 0;

end_rename:
	brelse(dir_bh);
	brelse(old_bh);
	brelse(new_bh);
	ext4_journal_stop(handle);
	if (retval == 0 && force_da_alloc)
		ext4_alloc_da_blocks(old_inode);
	return retval;
}

Project: linux
File: namei.c

static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
{
	int retval;
	struct inode *inode;
	struct buffer_head *bh;
	struct ext4_dir_entry_2 *de;
	handle_t *handle;

	/* Initialize quotas before so that eventual writes go in
	 * separate transaction */
	dquot_initialize(dir);
	dquot_initialize(dentry->d_inode);

	handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
	if (IS_ERR(handle))
		return PTR_ERR(handle);

	retval = -ENOENT;
	bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
	if (!bh)
		goto end_rmdir;

	if (IS_DIRSYNC(dir))
		ext4_handle_sync(handle);

	inode = dentry->d_inode;

	retval = -EIO;
	if (le32_to_cpu(de->inode) != inode->i_ino)
		goto end_rmdir;

	retval = -ENOTEMPTY;
	if (!empty_dir(inode))
		goto end_rmdir;

	retval = ext4_delete_entry(handle, dir, de, bh);
	if (retval)
		goto end_rmdir;
	if (!EXT4_DIR_LINK_EMPTY(inode))
		ext4_warning(inode->i_sb,
			     "empty directory has too many links (%d)",
			     inode->i_nlink);
	inode->i_version++;
	clear_nlink(inode);
	/* There's no need to set i_disksize: the fact that i_nlink is
	 * zero will ensure that the right thing happens during any
	 * recovery. */
	inode->i_size = 0;
	ext4_orphan_add(handle, inode);
	inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
	ext4_mark_inode_dirty(handle, inode);
	ext4_dec_count(handle, dir);
	ext4_update_dx_flag(dir);
	ext4_mark_inode_dirty(handle, dir);

end_rmdir:
	ext4_journal_stop(handle);
	brelse(bh);
	return retval;
}

Project: linux
File: namei.c

static inline void ext4_set_de_type(struct super_block *sb,
				struct ext4_dir_entry_2 *de,
				umode_t mode) {
	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
		de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
}

Project: linux
File: namei.c

static int ext4_symlink(struct inode *dir,
			struct dentry *dentry, const char *symname)
{
	handle_t *handle;
	struct inode *inode;
	int l, err, retries = 0;
	int credits;

	l = strlen(symname)+1;
	if (l > dir->i_sb->s_blocksize)
		return -ENAMETOOLONG;

	dquot_initialize(dir);

	if (l > EXT4_N_BLOCKS * 4) {
		/*
		 * For non-fast symlinks, we just allocate inode and put it on
		 * orphan list in the first transaction => we need bitmap,
		 * group descriptor, sb, inode block, quota blocks, and
		 * possibly selinux xattr blocks.
		 */
		credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
			  EXT4_XATTR_TRANS_BLOCKS;
	} else {
		/*
		 * Fast symlink. We have to add entry to directory
		 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
		 * allocate new inode (bitmap, group descriptor, inode block,
		 * quota blocks, sb is already counted in previous macros).
		 */
		credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
			  EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
			  EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
	}
retry:
	handle = ext4_journal_start(dir, credits);
	if (IS_ERR(handle))
		return PTR_ERR(handle);

	if (IS_DIRSYNC(dir))
		ext4_handle_sync(handle);

	inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO,
			       &dentry->d_name, 0, NULL);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_stop;

	if (l > EXT4_N_BLOCKS * 4) {
		inode->i_op = &ext4_symlink_inode_operations;
		ext4_set_aops(inode);
		/*
		 * We cannot call page_symlink() with transaction started
		 * because it calls into ext4_write_begin() which can wait
		 * for transaction commit if we are running out of space
		 * and thus we deadlock. So we have to stop transaction now
		 * and restart it when symlink contents is written.
		 * 
		 * To keep fs consistent in case of crash, we have to put inode
		 * to orphan list in the mean time.
		 */
		drop_nlink(inode);
		err = ext4_orphan_add(handle, inode);
		ext4_journal_stop(handle);
		if (err)
			goto err_drop_inode;
		err = __page_symlink(inode, symname, l, 1);
		if (err)
			goto err_drop_inode;
		/*
		 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
		 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
		 */
		handle = ext4_journal_start(dir,
				EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
				EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
		if (IS_ERR(handle)) {
			err = PTR_ERR(handle);
			goto err_drop_inode;
		}
		set_nlink(inode, 1);
		err = ext4_orphan_del(handle, inode);
		if (err) {
			ext4_journal_stop(handle);
			clear_nlink(inode);
			goto err_drop_inode;
		}
	} else {
		/* clear the extent format for fast symlink */
		ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
		inode->i_op = &ext4_fast_symlink_inode_operations;
		memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
		inode->i_size = l-1;
	}
	EXT4_I(inode)->i_disksize = inode->i_size;
	err = ext4_add_nondir(handle, dentry, inode);
out_stop:
	ext4_journal_stop(handle);
	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
		goto retry;
	return err;
err_drop_inode:
	unlock_new_inode(inode);
	iput(inode);
	return err;
}

Project: linux
File: namei.c

static int ext4_unlink(struct inode *dir, struct dentry *dentry)
{
	int retval;
	struct inode *inode;
	struct buffer_head *bh;
	struct ext4_dir_entry_2 *de;
	handle_t *handle;

	trace_ext4_unlink_enter(dir, dentry);
	/* Initialize quotas before so that eventual writes go
	 * in separate transaction */
	dquot_initialize(dir);
	dquot_initialize(dentry->d_inode);

	handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
	if (IS_ERR(handle))
		return PTR_ERR(handle);

	if (IS_DIRSYNC(dir))
		ext4_handle_sync(handle);

	retval = -ENOENT;
	bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
	if (!bh)
		goto end_unlink;

	inode = dentry->d_inode;

	retval = -EIO;
	if (le32_to_cpu(de->inode) != inode->i_ino)
		goto end_unlink;

	if (!inode->i_nlink) {
		ext4_warning(inode->i_sb,
			     "Deleting nonexistent file (%lu), %d",
			     inode->i_ino, inode->i_nlink);
		set_nlink(inode, 1);
	}
	retval = ext4_delete_entry(handle, dir, de, bh);
	if (retval)
		goto end_unlink;
	dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
	ext4_update_dx_flag(dir);
	ext4_mark_inode_dirty(handle, dir);
	drop_nlink(inode);
	if (!inode->i_nlink)
		ext4_orphan_add(handle, inode);
	inode->i_ctime = ext4_current_time(inode);
	ext4_mark_inode_dirty(handle, inode);
	retval = 0;

end_unlink:
	ext4_journal_stop(handle);
	brelse(bh);
	trace_ext4_unlink_exit(dentry, retval);
	return retval;
}

Project: linux
File: namei.c

static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
						   struct ext4_dir_entry *de)
{
	struct ext4_dir_entry_tail *t;

#ifdef PARANOID
	struct ext4_dir_entry *d, *top;

	d = de;
	top = (struct ext4_dir_entry *)(((void *)de) +
		(EXT4_BLOCK_SIZE(inode->i_sb) -
		sizeof(struct ext4_dir_entry_tail)));
	while (d < top && d->rec_len)
		d = (struct ext4_dir_entry *)(((void *)d) +
		    le16_to_cpu(d->rec_len));

	if (d != top)
		return NULL;

	t = (struct ext4_dir_entry_tail *)d;
#else
	t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
#endif

	if (t->det_reserved_zero1 ||
	    le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
	    t->det_reserved_zero2 ||
	    t->det_reserved_ft != EXT4_FT_DIR_CSUM)
		return NULL;

	return t;
}

Project: linux
File: namei.c

void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
			    unsigned int blocksize)
{
	memset(t, 0, sizeof(struct ext4_dir_entry_tail));
	t->det_rec_len = ext4_rec_len_to_disk(
			sizeof(struct ext4_dir_entry_tail), blocksize);
	t->det_reserved_ft = EXT4_FT_DIR_CSUM;
}

Project: linux
File: namei.c

static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
			       struct ext4_dir_entry *de)
{
	struct super_block *sb = dir->i_sb;

	if (!is_dx(dir))
		return 0;
	if (block == 0)
		return 1;
	if (de->inode == 0 &&
	    ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
			sb->s_blocksize)
		return 1;
	return 0;
}

Project: linux
File: namei.c

static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
			    struct inode *inode, struct buffer_head *bh)
{
	struct inode	*dir = dentry->d_parent->d_inode;
	const char	*name = dentry->d_name.name;
	int		namelen = dentry->d_name.len;
	struct buffer_head *bh2;
	struct dx_root	*root;
	struct dx_frame	frames[2], *frame;
	struct dx_entry *entries;
	struct ext4_dir_entry_2	*de, *de2;
	struct ext4_dir_entry_tail *t;
	char		*data1, *top;
	unsigned	len;
	int		retval;
	unsigned	blocksize;
	struct dx_hash_info hinfo;
	ext4_lblk_t  block;
	struct fake_dirent *fde;
	int		csum_size = 0;

	if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
		csum_size = sizeof(struct ext4_dir_entry_tail);

	blocksize =  dir->i_sb->s_blocksize;
	dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
	retval = ext4_journal_get_write_access(handle, bh);
	if (retval) {
		ext4_std_error(dir->i_sb, retval);
		brelse(bh);
		return retval;
	}
	root = (struct dx_root *) bh->b_data;

	/* The 0th block becomes the root, move the dirents out */
	fde = &root->dotdot;
	de = (struct ext4_dir_entry_2 *)((char *)fde +
		ext4_rec_len_from_disk(fde->rec_len, blocksize));
	if ((char *) de >= (((char *) root) + blocksize)) {
		EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
		brelse(bh);
		return -EIO;
	}
	len = ((char *) root) + (blocksize - csum_size) - (char *) de;

	/* Allocate new block for the 0th block's dirents */
	bh2 = ext4_append(handle, dir, &block, &retval);
	if (!(bh2)) {
		brelse(bh);
		return retval;
	}
	ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
	data1 = bh2->b_data;

	memcpy (data1, de, len);
	de = (struct ext4_dir_entry_2 *) data1;
	top = data1 + len;
	while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
		de = de2;
	de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
					   (char *) de,
					   blocksize);

	if (csum_size) {
		t = EXT4_DIRENT_TAIL(data1, blocksize);
		initialize_dirent_tail(t, blocksize);
	}

	/* Initialize the root; the dot dirents already exist */
	de = (struct ext4_dir_entry_2 *) (&root->dotdot);
	de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
					   blocksize);
	memset (&root->info, 0, sizeof(root->info));
	root->info.info_length = sizeof(root->info);
	root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
	entries = root->entries;
	dx_set_block(entries, 1);
	dx_set_count(entries, 1);
	dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));

	/* Initialize as for dx_probe */
	hinfo.hash_version = root->info.hash_version;
	if (hinfo.hash_version <= DX_HASH_TEA)
		hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
	hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
	ext4fs_dirhash(name, namelen, &hinfo);
	frame = frames;
	frame->entries = entries;
	frame->at = entries;
	frame->bh = bh;
	bh = bh2;

	ext4_handle_dirty_dx_node(handle, dir, frame->bh);
	ext4_handle_dirty_dirent_node(handle, dir, bh);

	de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
	if (!de) {
		/*
		 * Even if the block split failed, we have to properly write
		 * out all the changes we did so far. Otherwise we can end up
		 * with corrupted filesystem.
		 */
		ext4_mark_inode_dirty(handle, dir);
		dx_release(frames);
		return retval;
	}
	dx_release(frames);

	retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
	brelse(bh);
	return retval;
}

Project: linux
File: namei.c

int search_dir(struct buffer_head *bh,
	       char *search_buf,
	       int buf_size,
	       struct inode *dir,
	       const struct qstr *d_name,
	       unsigned int offset,
	       struct ext4_dir_entry_2 **res_dir)
{
	struct ext4_dir_entry_2 * de;
	char * dlimit;
	int de_len;
	const char *name = d_name->name;
	int namelen = d_name->len;

	de = (struct ext4_dir_entry_2 *)search_buf;
	dlimit = search_buf + buf_size;
	while ((char *) de < dlimit) {
		/* this code is executed quadratically often */
		/* do minimal checking `by hand' */

		if ((char *) de + namelen <= dlimit &&
		    ext4_match (namelen, name, de)) {
			/* found a match - just to be sure, do a full check */
			if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
						 bh->b_size, offset))
				return -1;
			*res_dir = de;
			return 1;
		}
		/* prevent looping on a bad block */
		de_len = ext4_rec_len_from_disk(de->rec_len,
						dir->i_sb->s_blocksize);
		if (de_len <= 0)
			return -1;
		offset += de_len;
		de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
	}
	return 0;
}

Project: linux
File: namei.c

static inline int search_dirblock(struct buffer_head *bh,
				  struct inode *dir,
				  const struct qstr *d_name,
				  unsigned int offset,
				  struct ext4_dir_entry_2 **res_dir)
{
	return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
			  d_name, offset, res_dir);
}

Project: linux
File: namei.c

static void warn_no_space_for_csum(struct inode *inode)
{
	ext4_warning(inode->i_sb, "no space in directory inode %lu leaf for "
		     "checksum.  Please run e2fsck -D.", inode->i_ino);
}