diff options
| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2026-05-18 13:23:40 +0900 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-05-28 21:24:57 -0700 |
| commit | f5b1910e23f1233c8d4185268b2e659df2bc5dbf (patch) | |
| tree | 562b4c93a89b5c16ed609e371d4bf69340bcb389 /fs | |
| parent | f7ea0d13735ef812f7c777d5c0a79ff6a4b369c3 (diff) | |
| download | linux-next-history-f5b1910e23f1233c8d4185268b2e659df2bc5dbf.tar.gz | |
ocfs2: kill osb->system_file_mutex lock
Commit 43b10a20372d ("ocfs2: avoid system inode ref confusion by adding
mutex lock") tried to avoid a refcount leak caused by allowing multiple
threads to call igrab(inode). But addition of osb->system_file_mutex made
locking dependency complicated and is causing lockdep to warn about
possibility of AB-BA deadlock.
Since _ocfs2_get_system_file_inode() returns the same inode for the same
input arguments, we don't need to serialize
_ocfs2_get_system_file_inode(). What we need to make sure is that
igrab(inode) is called for only once(). Therefore, replace
osb->system_file_mutex with cmpxchg()-based locking.
Link: https://lore.kernel.org/fea8d1fd-afb0-4302-a560-c202e2ef7afd@I-love.SAKURA.ne.jp
Fixes: 43b10a20372d ("ocfs2: avoid system inode ref confusion by adding mutex lock")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Heming Zhao <heming.zhao@suse.com>
Acked-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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ocfs2/ocfs2.h | 2 | ||||
| -rw-r--r-- | fs/ocfs2/super.c | 2 | ||||
| -rw-r--r-- | fs/ocfs2/sysfile.c | 9 |
3 files changed, 3 insertions, 10 deletions
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h index 7b50e03dfa664..62cad6522c7a3 100644 --- a/fs/ocfs2/ocfs2.h +++ b/fs/ocfs2/ocfs2.h @@ -494,8 +494,6 @@ struct ocfs2_super struct rb_root osb_rf_lock_tree; struct ocfs2_refcount_tree *osb_ref_tree_lru; - struct mutex system_file_mutex; - /* * OCFS2 needs to schedule several different types of work which * require cluster locking, disk I/O, recovery waits, etc. Since these diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index b875f01c97564..6dd45c2153f88 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -1997,8 +1997,6 @@ static int ocfs2_initialize_super(struct super_block *sb, spin_lock_init(&osb->osb_xattr_lock); ocfs2_init_steal_slots(osb); - mutex_init(&osb->system_file_mutex); - atomic_set(&osb->alloc_stats.moves, 0); atomic_set(&osb->alloc_stats.local_data, 0); atomic_set(&osb->alloc_stats.bitmap_data, 0); diff --git a/fs/ocfs2/sysfile.c b/fs/ocfs2/sysfile.c index d53a6cc866bef..67e492f4b828b 100644 --- a/fs/ocfs2/sysfile.c +++ b/fs/ocfs2/sysfile.c @@ -98,11 +98,9 @@ struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb, } else arr = get_local_system_inode(osb, type, slot); - mutex_lock(&osb->system_file_mutex); if (arr && ((inode = *arr) != NULL)) { /* get a ref in addition to the array ref */ inode = igrab(inode); - mutex_unlock(&osb->system_file_mutex); BUG_ON(!inode); return inode; @@ -112,11 +110,10 @@ struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb, inode = _ocfs2_get_system_file_inode(osb, type, slot); /* add one more if putting into array for first time */ - if (arr && inode) { - *arr = igrab(inode); - BUG_ON(!*arr); + if (inode && arr && !*arr && !cmpxchg(&(*arr), NULL, inode)) { + inode = igrab(inode); + BUG_ON(!inode); } - mutex_unlock(&osb->system_file_mutex); return inode; } |