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| author | Deepanshu Kartikey <kartikey406@gmail.com> | 2026-06-21 04:42:23 +0530 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-07-22 21:14:09 -0700 |
| commit | 695aa786e686f7ae61a7ff2d2a98b98b83680707 (patch) | |
| tree | f03b887669ed77c88157d00327f6791528bd298e | |
| parent | f0bc1c9083dbf7497eef4d9cd8ec55e5e5cb3929 (diff) | |
| download | linux-next-695aa786e686f7ae61a7ff2d2a98b98b83680707.tar.gz linux-next-695aa786e686f7ae61a7ff2d2a98b98b83680707.zip | |
ocfs2: use inode_lock_nested() for orphan dir locking
PREEMPT_RT's rtmutex PI chain walker warns about a lock dependency cycle
when inode_lock(orphan_dir_inode) is called while holding
inode_lock(file_inode):
ocfs2_file_write_iter()
inode_lock(file_inode) [class 0]
ocfs2_dio_end_io_write()
ocfs2_del_inode_from_orphan()
inode_lock(orphan_dir_inode) [class 0] <- warning!
However this is a false positive. write_iter() is never called on a
directory, and orphan_dir is always a directory, so these two locks can
never actually conflict in practice.
Fix by using inode_lock_nested(orphan_dir_inode, I_MUTEX_NONDIR2) in all
three places where orphan_dir_inode is locked in namei.c, placing it in a
separate lock class so the rtmutex PI chain walker understands these locks
have distinct roles and does not warn about their ordering.
Link: https://lore.kernel.org/20260620231223.46588-1-kartikey406@gmail.com
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Reported-by: syzbot+ce129763ce7d7e914739@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=ce129763ce7d7e914739
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Heming Zhao <heming.zhao@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | fs/ocfs2/namei.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c index 1277666c77cd..4cfd7b3d3e1a 100644 --- a/fs/ocfs2/namei.c +++ b/fs/ocfs2/namei.c @@ -2126,7 +2126,7 @@ static int ocfs2_lookup_lock_orphan_dir(struct ocfs2_super *osb, return ret; } - inode_lock(orphan_dir_inode); + inode_lock_nested(orphan_dir_inode, I_MUTEX_NONDIR2); ret = ocfs2_inode_lock(orphan_dir_inode, &orphan_dir_bh, 1); if (ret < 0) { @@ -2725,7 +2725,7 @@ int ocfs2_del_inode_from_orphan(struct ocfs2_super *osb, goto bail; } - inode_lock(orphan_dir_inode); + inode_lock_nested(orphan_dir_inode, I_MUTEX_NONDIR2); status = ocfs2_inode_lock(orphan_dir_inode, &orphan_dir_bh, 1); if (status < 0) { inode_unlock(orphan_dir_inode); @@ -2838,7 +2838,7 @@ int ocfs2_mv_orphaned_inode_to_new(struct inode *dir, goto leave; } - inode_lock(orphan_dir_inode); + inode_lock_nested(orphan_dir_inode, I_MUTEX_NONDIR2); status = ocfs2_inode_lock(orphan_dir_inode, &orphan_dir_bh, 1); if (status < 0) { |