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Commit 20a3d61d authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
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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: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent fe8494bf

fs/f2fs/file.c

+7 −2
Original line number Diff line number Diff line
@@ -2093,8 +2093,12 @@ static int f2fs_move_file_range(struct file *file_in, loff_t pos_in, 
		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 @@ static int f2fs_move_file_range(struct file *file_in, loff_t pos_in, 
out_unlock:

	if (src != dst)

		inode_unlock(dst);

out:

	inode_unlock(src);

	return ret;

}