Commit 5f58d783 authored by Anand Jain's avatar Anand Jain Committed by David Sterba

btrfs: free device in btrfs_close_devices for a single device filesystem

We have this check to make sure we don't accidentally add older devices
that may have disappeared and re-appeared with an older generation from
being added to an fs_devices (such as a replace source device). This
makes sense, we don't want stale disks in our file system. However for
single disks this doesn't really make sense.

I've seen this in testing, but I was provided a reproducer from a
project that builds btrfs images on loopback devices. The loopback
device gets cached with the new generation, and then if it is re-used to
generate a new file system we'll fail to mount it because the new fs is
"older" than what we have in cache.

Fix this by freeing the cache when closing the device for a single device
filesystem. This will ensure that the mount command passed device path is
scanned successfully during the next mount.

CC: stable@vger.kernel.org # 5.10+
Reported-by: default avatarDaan De Meyer <daandemeyer@fb.com>
Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarAnand Jain <anand.jain@oracle.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 519b7e13
......@@ -403,6 +403,7 @@ void btrfs_free_device(struct btrfs_device *device)
static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
{
struct btrfs_device *device;
WARN_ON(fs_devices->opened);
while (!list_empty(&fs_devices->devices)) {
device = list_entry(fs_devices->devices.next,
......@@ -1181,9 +1182,22 @@ void btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
mutex_lock(&uuid_mutex);
close_fs_devices(fs_devices);
if (!fs_devices->opened)
if (!fs_devices->opened) {
list_splice_init(&fs_devices->seed_list, &list);
/*
* If the struct btrfs_fs_devices is not assembled with any
* other device, it can be re-initialized during the next mount
* without the needing device-scan step. Therefore, it can be
* fully freed.
*/
if (fs_devices->num_devices == 1) {
list_del(&fs_devices->fs_list);
free_fs_devices(fs_devices);
}
}
list_for_each_entry_safe(fs_devices, tmp, &list, seed_list) {
close_fs_devices(fs_devices);
list_del(&fs_devices->seed_list);
......
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