From: Anand Jain <anand.j...@oracle.com>
commit 96c2e067ed3e3e004580a643c76f58729206b829 upstream.
Many things can happen after the device is scanned and before the device
is mounted. One such thing is losing the BTRFS_MAGIC on the device.
If it happens we still won't free that device from the memory and cause
the userland confusion.
For example: As the BTRFS_IOC_DEV_INFO still carries the device path
which does not have the BTRFS_MAGIC, 'btrfs fi show' still lists
device which does not belong to the filesystem anymore:
$ mkfs.btrfs -fq -draid1 -mraid1 /dev/sda /dev/sdb
$ wipefs -a /dev/sdb
# /dev/sdb does not contain magic signature
$ mount -o degraded /dev/sda /btrfs
$ btrfs fi show -m
Label: none uuid: 470ec6fb-646b-4464-b3cb-df1b26c527bd
Total devices 2 FS bytes used 128.00KiB
devid 1 size 3.00GiB used 571.19MiB path /dev/sda
devid 2 size 3.00GiB used 571.19MiB path /dev/sdb
We need to distinguish the missing signature and invalid superblock, so
add a specific error code ENODATA for that. This also fixes failure of
fstest btrfs/198.
CC: sta...@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <jo...@toxicpanda.com>
Signed-off-by: Anand Jain <anand.j...@oracle.com>
Reviewed-by: David Sterba <dste...@suse.com>
Signed-off-by: David Sterba <dste...@suse.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
fs/btrfs/disk-io.c | 8 ++++++--
fs/btrfs/volumes.c | 18 ++++++++++++------
2 files changed, 18 insertions(+), 8 deletions(-)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3482,8 +3482,12 @@ struct btrfs_super_block *btrfs_read_dev
return ERR_CAST(page);
super = page_address(page);
- if (btrfs_super_bytenr(super) != bytenr ||
- btrfs_super_magic(super) != BTRFS_MAGIC) {
+ if (btrfs_super_magic(super) != BTRFS_MAGIC) {
+ btrfs_release_disk_super(super);
+ return ERR_PTR(-ENODATA);
+ }
+
+ if (btrfs_super_bytenr(super) != bytenr) {
btrfs_release_disk_super(super);
return ERR_PTR(-EINVAL);
}
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1200,17 +1200,23 @@ static int open_fs_devices(struct btrfs_
{
struct btrfs_device *device;
struct btrfs_device *latest_dev = NULL;
+ struct btrfs_device *tmp_device;
flags |= FMODE_EXCL;
- list_for_each_entry(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;
+ list_for_each_entry_safe(device, tmp_device, &fs_devices->devices,
+ dev_list) {
+ int ret;
- if (!latest_dev ||
- device->generation > latest_dev->generation)
+ ret = btrfs_open_one_device(fs_devices, device, flags, holder);
+ if (ret == 0 &&
+ (!latest_dev || device->generation >
latest_dev->generation)) {
latest_dev = device;
+ } else if (ret == -ENODATA) {
+ fs_devices->num_devices--;
+ list_del(&device->dev_list);
+ btrfs_free_device(device);
+ }
}
if (fs_devices->open_devices == 0)
return -EINVAL;
