From 20a3d61d46e1fb45efa6eb4637c0dcd3f00a14e9 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Thu, 4 Aug 2016 20:13:03 +0800 Subject: [PATCH] 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 Signed-off-by: Jaegeuk Kim --- fs/f2fs/file.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 685e629f768b..47abb96098e4 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -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; } -- GitLab