ext3: Replace lock/unlock_super() with an explicit lock for the orphan list

Use a separate lock to protect the orphan list, so we can stop
overloading the use of lock_super().

Port of ext4 commit 3b9d4ed266
by Theodore Ts'o <tytso@mit.edu>.

CC: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Eric Sandeen 2009-12-14 13:00:30 -06:00 committed by Jan Kara
parent 4854a5f0cb
commit b8a052d016
3 changed files with 13 additions and 9 deletions

View file

@ -1920,7 +1920,7 @@ int ext3_orphan_add(handle_t *handle, struct inode *inode)
struct ext3_iloc iloc;
int err = 0, rc;
lock_super(sb);
mutex_lock(&EXT3_SB(sb)->s_orphan_lock);
if (!list_empty(&EXT3_I(inode)->i_orphan))
goto out_unlock;
@ -1929,9 +1929,13 @@ int ext3_orphan_add(handle_t *handle, struct inode *inode)
/* @@@ FIXME: Observation from aviro:
* I think I can trigger J_ASSERT in ext3_orphan_add(). We block
* here (on lock_super()), so race with ext3_link() which might bump
* here (on s_orphan_lock), so race with ext3_link() which might bump
* ->i_nlink. For, say it, character device. Not a regular file,
* not a directory, not a symlink and ->i_nlink > 0.
*
* tytso, 4/25/2009: I'm not sure how that could happen;
* shouldn't the fs core protect us from these sort of
* unlink()/link() races?
*/
J_ASSERT ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
@ -1968,7 +1972,7 @@ int ext3_orphan_add(handle_t *handle, struct inode *inode)
jbd_debug(4, "orphan inode %lu will point to %d\n",
inode->i_ino, NEXT_ORPHAN(inode));
out_unlock:
unlock_super(sb);
mutex_unlock(&EXT3_SB(sb)->s_orphan_lock);
ext3_std_error(inode->i_sb, err);
return err;
}
@ -1986,11 +1990,9 @@ int ext3_orphan_del(handle_t *handle, struct inode *inode)
struct ext3_iloc iloc;
int err = 0;
lock_super(inode->i_sb);
if (list_empty(&ei->i_orphan)) {
unlock_super(inode->i_sb);
return 0;
}
mutex_lock(&EXT3_SB(inode->i_sb)->s_orphan_lock);
if (list_empty(&ei->i_orphan))
goto out;
ino_next = NEXT_ORPHAN(inode);
prev = ei->i_orphan.prev;
@ -2040,7 +2042,7 @@ int ext3_orphan_del(handle_t *handle, struct inode *inode)
out_err:
ext3_std_error(inode->i_sb, err);
out:
unlock_super(inode->i_sb);
mutex_unlock(&EXT3_SB(inode->i_sb)->s_orphan_lock);
return err;
out_brelse:

View file

@ -1928,6 +1928,7 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
sb->dq_op = &ext3_quota_operations;
#endif
INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
mutex_init(&sbi->s_orphan_lock);
sb->s_root = NULL;

View file

@ -72,6 +72,7 @@ struct ext3_sb_info {
struct inode * s_journal_inode;
struct journal_s * s_journal;
struct list_head s_orphan;
struct mutex s_orphan_lock;
unsigned long s_commit_interval;
struct block_device *journal_bdev;
#ifdef CONFIG_JBD_DEBUG