From c57c2b3ed248b3f1712e4172eb85b361199582f2 Mon Sep 17 00:00:00 2001 From: Filipe David Borba Manana Date: Sat, 11 Jan 2014 21:31:25 +0000 Subject: [PATCH] Btrfs: unlock inodes in correct order in clone ioctl In the clone ioctl, when the source and target inodes are different, we can acquire their mutexes in 2 possible different orders. After we're done cloning, we were releasing the mutexes always in the same order - the most correct way of doing it is to release them by the reverse order they were acquired. Signed-off-by: Filipe David Borba Manana Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/ioctl.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 332b624..5ed5bd0 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3263,9 +3263,17 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1); out_unlock: - mutex_unlock(&src->i_mutex); - if (!same_inode) - mutex_unlock(&inode->i_mutex); + if (!same_inode) { + if (inode < src) { + mutex_unlock(&src->i_mutex); + mutex_unlock(&inode->i_mutex); + } else { + mutex_unlock(&inode->i_mutex); + mutex_unlock(&src->i_mutex); + } + } else { + mutex_unlock(&src->i_mutex); + } out_fput: fdput(src_file); out_drop_write: -- 2.7.4