From fbf186bf87e727ccad5f476b54e240e3bd6d2350 Mon Sep 17 00:00:00 2001 From: Anand Jain Date: Mon, 24 Feb 2014 19:43:39 +0800 Subject: [PATCH] btrfs-progs: Fix bug when scanned for devid which was missing and deleted get_fs_info() provides the info of the specific device/devid, however when we delete the missing disk the super-block on the disk isn't cleared, and since btrfs-progs makes its decision by reading the disk super block, so it doesn't know about the kernel previous action, And now when we tried to probe kernel for the devid it fails. reproducer: $ mkfs.btrfs -d raid1 -m raid1 /dev/sde /dev/sdf $ modprobe -r btrfs && modprobe btrfs $ mount -o degraded /dev/sde /btrfs $ btrfs dev add /dev/sdd /btrfs $ btrfs dev del missing /btrfs $ btrfs scrub start -B /dev/sdf btrfs: utils.c:1741: get_fs_info: Assertion `!(ndevs == 0)' failed. Aborted (core dumped) Signed-off-by: Anand Jain Signed-off-by: David Sterba Signed-off-by: Chris Mason --- utils.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/utils.c b/utils.c index ef7fb46..78e4ba1 100644 --- a/utils.c +++ b/utils.c @@ -1752,8 +1752,15 @@ int get_fs_info(char *path, struct btrfs_ioctl_fs_info_args *fi_args, ndevs++; } - BUG_ON(ndevs == 0); - ret = 0; + /* + * only when the only dev we wanted to find is not there then + * let any error be returned + */ + if (fi_args->num_devices != 1) { + BUG_ON(ndevs == 0); + ret = 0; + } + out: close_file_or_dir(fd, dirstream); return ret; -- 2.7.4