From: Anand Jain <anand.jain@xxxxxxxxxx> commit 59a3991984dbc1fc47e5651a265c5200bd85464e upstream. If the filesystem mounts with the replace-operation in a suspended state and try to cancel the suspended replace-operation, we hit the assert. The assert came from the commit fe97e2e173af ("btrfs: dev-replace: replace's scrub must not be running in suspended state") that was actually not required. So just remove it. $ mount /dev/sda5 /btrfs BTRFS info (device sda5): cannot continue dev_replace, tgtdev is missing BTRFS info (device sda5): you may cancel the operation after 'mount -o degraded' $ mount -o degraded /dev/sda5 /btrfs <-- success. $ btrfs replace cancel /btrfs kernel: assertion failed: ret != -ENOTCONN, in fs/btrfs/dev-replace.c:1131 kernel: ------------[ cut here ]------------ kernel: kernel BUG at fs/btrfs/ctree.h:3750! After the patch: $ btrfs replace cancel /btrfs BTRFS info (device sda5): suspended dev_replace from /dev/sda5 (devid 1) to <missing disk> canceled Fixes: fe97e2e173af ("btrfs: dev-replace: replace's scrub must not be running in suspended state") CC: stable@xxxxxxxxxxxxxxx # 5.0+ Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/btrfs/dev-replace.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -1128,8 +1128,7 @@ int btrfs_dev_replace_cancel(struct btrf up_write(&dev_replace->rwsem); /* Scrub for replace must not be running in suspended state */ - ret = btrfs_scrub_cancel(fs_info); - ASSERT(ret != -ENOTCONN); + btrfs_scrub_cancel(fs_info); trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) {