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authorjiangyiwen <jiangyiwen@huawei.com>2014-04-03 14:47:13 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-03 16:20:57 -0700
commit43b10a20372d9a1c08391f33f1c8bd86179ddc5f (patch)
treeed5fd7ca5fd34c4d84393e7fb3d65b8512594382 /fs/ocfs2/super.c
parent7dc3e83901b342ea7fe36262329c3784f2937361 (diff)
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ocfs2: avoid system inode ref confusion by adding mutex lock
The following case may lead to the same system inode ref in confusion. A thread B thread ocfs2_get_system_file_inode ->get_local_system_inode ->_ocfs2_get_system_file_inode because of *arr == NULL, ocfs2_get_system_file_inode ->get_local_system_inode ->_ocfs2_get_system_file_inode gets first ref thru _ocfs2_get_system_file_inode, gets second ref thru igrab and set *arr = inode at the moment, B thread also gets two refs, so lead to one more inode ref. So add mutex lock to avoid multi thread set two inode ref once at the same time. Signed-off-by: jiangyiwen <jiangyiwen@huawei.com> Reviewed-by: Joseph Qi <joseph.qi@huawei.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ocfs2/super.c')
-rw-r--r--fs/ocfs2/super.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 888a1457af96..1aecd626e645 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -2100,6 +2100,8 @@ 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);