[PATCH v3 3/5] btrfs: remove identified alien btrfs device in open_fs_devices

[Anand Jain]

In open_fs_devices() we identify alien device but we don't reset its
the device::name. So progs device list does not show the device missing
as shown in the script below.

mkfs.btrfs -fq /dev/sdd && mount /dev/sdd /btrfs
mkfs.btrfs -fq -draid1 -mraid1 /dev/sdc /dev/sdb
sleep 3 # avoid racing with udev's useless scans if needed
btrfs dev add -f /dev/sdb /btrfs
mount -o degraded /dev/sdc /btrfs1

No missing device:
btrfs fi show -m /btrfs1
Label: none  uuid: 3eb7cd50-4594-458f-9d68-c243cc49954d
        Total devices 2 FS bytes used 128.00KiB
        devid    1 size 12.00GiB used 1.26GiB path /dev/sdc
        devid    2 size 12.00GiB used 1.26GiB path /dev/sdb

Signed-off-by: Anand Jain <anand.j...@oracle.com>
---
v3: Fix nit, rearrange code to remove continue.
v2: Move free alien part to its parent function btrfs_open_one_device.
    Thanks Nikolay.

 fs/btrfs/volumes.c | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 0cc8d40b8bb9..81097c80ac4a 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -591,13 +591,18 @@ static int btrfs_open_one_device(struct btrfs_fs_devices 
*fs_devices,
        if (ret)
                return ret;
 
+       ret = -EINVAL;
        disk_super = (struct btrfs_super_block *)bh->b_data;
        devid = btrfs_stack_device_id(&disk_super->dev_item);
-       if (devid != device->devid)
+       if (devid != device->devid) {
+               ret = -EUCLEAN;
                goto error_brelse;
+       }
 
-       if (memcmp(device->uuid, disk_super->dev_item.uuid, BTRFS_UUID_SIZE))
+       if (memcmp(device->uuid, disk_super->dev_item.uuid, BTRFS_UUID_SIZE)) {
+               ret = -EUCLEAN;
                goto error_brelse;
+       }
 
        device->generation = btrfs_super_generation(disk_super);
 
@@ -640,7 +645,7 @@ static int btrfs_open_one_device(struct btrfs_fs_devices 
*fs_devices,
        brelse(bh);
        blkdev_put(bdev, flags);
 
-       return -EINVAL;
+       return ret;
 }
 
 /*
@@ -1123,18 +1128,25 @@ int btrfs_close_devices(struct btrfs_fs_devices 
*fs_devices)
 static int open_fs_devices(struct btrfs_fs_devices *fs_devices,
                                fmode_t flags, void *holder)
 {
+       int ret;
        struct btrfs_device *device;
+       struct btrfs_device *tmp_device;
        struct btrfs_device *latest_dev = NULL;
 
        flags |= FMODE_EXCL;
 
-       list_for_each_entry(device, &fs_devices->devices, dev_list) {
+       list_for_each_entry_safe(device, tmp_device, &fs_devices->devices,
+                                dev_list) {
                /* Just open everything we can; ignore failures here */
-               if (btrfs_open_one_device(fs_devices, device, flags, holder))
-                       continue;
-
-               if (!latest_dev ||
-                   device->generation > latest_dev->generation)
+               ret = btrfs_open_one_device(fs_devices, device, flags, holder);
+               if (ret == -EUCLEAN) {
+                       /* Its an alien device, remove it from the list */
+                       fs_devices->num_devices--;
+                       list_del(&device->dev_list);
+                       btrfs_free_device(device);
+               }
+               if (ret == 0 && (!latest_dev ||
+                   device->generation > latest_dev->generation))
                        latest_dev = device;
        }
        if (fs_devices->open_devices == 0)
-- 
1.8.3.1