f2fs: avoid potential deadlock in f2fs_move_file_range
Thread A Thread B
- inode_lock fileA
- inode_lock fileB
- inode_lock fileA
- inode_lock fileB
We may encounter above potential deadlock during moving file range in
concurrent scenario. This patch fixes the issue by using inode_trylock
instead.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 685e629..47abb96 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2093,8 +2093,12 @@
return -EOPNOTSUPP;
inode_lock(src);
- if (src != dst)
- inode_lock(dst);
+ if (src != dst) {
+ if (!inode_trylock(dst)) {
+ ret = -EBUSY;
+ goto out;
+ }
+ }
ret = -EINVAL;
if (pos_in + len > src->i_size || pos_in + len < pos_in)
@@ -2152,6 +2156,7 @@
out_unlock:
if (src != dst)
inode_unlock(dst);
+out:
inode_unlock(src);
return ret;
}