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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2009-05-08 01:05:06 +0200 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2009-09-14 07:18:17 +0200 |
| commit | b1c839bb2d8d6f1f6bf48f5c657752b4963f88f8 (patch) | |
| tree | 7396e1e56cfe544248d0e21374ab10f4edf6de3a /fs | |
| parent | 26931309a47747fd31b2ef029c29d47794c2d93d (diff) | |
| download | op-kernel-dev-b1c839bb2d8d6f1f6bf48f5c657752b4963f88f8.zip op-kernel-dev-b1c839bb2d8d6f1f6bf48f5c657752b4963f88f8.tar.gz | |
kill-the-bkl/reiserfs: don't hold the write recursively in reiserfs_lookup()
The write lock can be acquired recursively in reiserfs_lookup(). But we may
want to *really* release the lock before possible rescheduling from a
reiserfs_lookup() callee.
Hence we want to only acquire the lock once (ie: not recursively).
[ Impact: prevent from possible false unreleased write lock on sleeping ]
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/reiserfs/namei.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c index 2715791..b3973c9 100644 --- a/fs/reiserfs/namei.c +++ b/fs/reiserfs/namei.c @@ -324,6 +324,7 @@ static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { int retval; + int lock_depth; struct inode *inode = NULL; struct reiserfs_dir_entry de; INITIALIZE_PATH(path_to_entry); @@ -331,7 +332,13 @@ static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry, if (REISERFS_MAX_NAME(dir->i_sb->s_blocksize) < dentry->d_name.len) return ERR_PTR(-ENAMETOOLONG); - reiserfs_write_lock(dir->i_sb); + /* + * Might be called with or without the write lock, must be careful + * to not recursively hold it in case we want to release the lock + * before rescheduling. + */ + lock_depth = reiserfs_write_lock_once(dir->i_sb); + de.de_gen_number_bit_string = NULL; retval = reiserfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, @@ -341,7 +348,7 @@ static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry, inode = reiserfs_iget(dir->i_sb, (struct cpu_key *)&(de.de_dir_id)); if (!inode || IS_ERR(inode)) { - reiserfs_write_unlock(dir->i_sb); + reiserfs_write_unlock_once(dir->i_sb, lock_depth); return ERR_PTR(-EACCES); } @@ -350,7 +357,7 @@ static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry, if (IS_PRIVATE(dir)) inode->i_flags |= S_PRIVATE; } - reiserfs_write_unlock(dir->i_sb); + reiserfs_write_unlock_once(dir->i_sb, lock_depth); if (retval == IO_ERROR) { return ERR_PTR(-EIO); } |
