Btrfs: skip submitting barrier for missing device

I got an error on v3.13:
 BTRFS error (device sdf1) in write_all_supers:3378: errno=-5 IO failure (errors while submitting device barriers.)

how to reproduce:
  > mkfs.btrfs -f -d raid1 /dev/sdf1 /dev/sdf2
  > wipefs -a /dev/sdf2
  > mount -o degraded /dev/sdf1 /mnt
  > btrfs balance start -f -sconvert=single -mconvert=single -dconvert=single /mnt

The reason of the error is that barrier_all_devices() failed to submit
barrier to the missing device.  However it is clear that we cannot do
anything on missing device, and also it is not necessary to care chunks
on the missing device.

This patch stops sending/waiting barrier if device is missing.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Josef Bacik <jbacik@fb.com>

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 0cafacb07b43fd02dda1432d7d3ce958f6f59974..74c9be89fc0c83adae621010b4712579748064a1 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3256,6 +3256,8 @@ static int barrier_all_devices(struct btrfs_fs_info *info)
        /* send down all the barriers */
        head = &info->fs_devices->devices;
        list_for_each_entry_rcu(dev, head, dev_list) {
+               if (dev->missing)
+                       continue;
                if (!dev->bdev) {
                        errors_send++;
                        continue;
@@ -3270,6 +3272,8 @@ static int barrier_all_devices(struct btrfs_fs_info *info)
 
        /* wait for all the barriers */
        list_for_each_entry_rcu(dev, head, dev_list) {
+               if (dev->missing)
+                       continue;
                if (!dev->bdev) {
                        errors_wait++;
                        continue;