Btrfs: skip submitting barrier for missing device

commit f88ba6a2a44ee98e8d59654463dc157bb6d13c43 upstream.

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>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 6b2a7248ca8bbedb7f31602fa07f5461239c7f22..cfdf6feec104c9a5919d054ba36029c86d9125fb 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2731,6 +2731,8 @@ 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++;
                        continue;
@@ -2745,6 +2747,8 @@ 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++;
                        continue;