4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Anand Jain <anand.jain@xxxxxxxxxx> [ Upstream commit 4306a97449f9a0f9e5229af7889d4401315355aa ] btrfs_free_stale_devices() looks for device path reused for another filesystem, and deletes the older fs_devices::device entry. In preparation to handle locking in device_list_add, move btrfs_free_stale_devices outside as these two functions serve a different purpose. Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx> Reviewed-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/btrfs/volumes.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -750,7 +750,8 @@ error_brelse: * error pointer when failed */ static noinline struct btrfs_device *device_list_add(const char *path, - struct btrfs_super_block *disk_super) + struct btrfs_super_block *disk_super, + bool *new_device_added) { struct btrfs_device *device; struct btrfs_fs_devices *fs_devices; @@ -796,7 +797,7 @@ static noinline struct btrfs_device *dev mutex_unlock(&fs_devices->device_list_mutex); device->fs_devices = fs_devices; - btrfs_free_stale_devices(path, device); + *new_device_added = true; if (disk_super->label[0]) pr_info("BTRFS: device label %s devid %llu transid %llu %s\n", @@ -1221,6 +1222,7 @@ int btrfs_scan_one_device(const char *pa struct btrfs_fs_devices **fs_devices_ret) { struct btrfs_super_block *disk_super; + bool new_device_added = false; struct btrfs_device *device; struct block_device *bdev; struct page *page; @@ -1246,11 +1248,14 @@ int btrfs_scan_one_device(const char *pa } mutex_lock(&uuid_mutex); - device = device_list_add(path, disk_super); - if (IS_ERR(device)) + device = device_list_add(path, disk_super, &new_device_added); + if (IS_ERR(device)) { ret = PTR_ERR(device); - else + } else { *fs_devices_ret = device->fs_devices; + if (new_device_added) + btrfs_free_stale_devices(path, device); + } mutex_unlock(&uuid_mutex); btrfs_release_disk_super(page);