diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index ce14ce068a84..a89596c3de56 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -405,6 +405,21 @@ static noinline struct btrfs_fs_devices *find_fsid( return fs_devices; } } + /* + * Handle scanned device having completed its fsid change but + * belonging to a fs_devices that was created by a device that + * has an outdated pair of fsid/metadata_uuid and + * CHANGING_FSID_V2 flag set. + */ + list_for_each_entry(fs_devices, &fs_uuids, fs_list) { + if (fs_devices->fsid_change && + memcmp(fs_devices->metadata_uuid, + fs_devices->fsid, BTRFS_FSID_SIZE) != 0 && + memcmp(metadata_fsid, fs_devices->metadata_uuid, + BTRFS_FSID_SIZE) == 0) { + return fs_devices; + } + } } /* Handle non-split brain cases */ @@ -814,6 +829,30 @@ static struct btrfs_fs_devices *find_fsid_inprogress( return NULL; } + +static struct btrfs_fs_devices *find_fsid_changed( + struct btrfs_super_block *disk_super) +{ + struct btrfs_fs_devices *fs_devices; + + /* + * Handles the case where scanned device is part of an fs that had + * multiple successful changes of FSID but curently device didn't + * observe it. Meaning our fsid will be different than theirs. + */ + list_for_each_entry(fs_devices, &fs_uuids, fs_list) { + if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid, + BTRFS_FSID_SIZE) != 0 && + memcmp(fs_devices->metadata_uuid, disk_super->metadata_uuid, + BTRFS_FSID_SIZE) == 0 && + memcmp(fs_devices->fsid, disk_super->fsid, + BTRFS_FSID_SIZE) != 0) { + return fs_devices; + } + } + + return NULL; +} /* * Add new device to list of registered devices * @@ -835,17 +874,20 @@ static noinline struct btrfs_device *device_list_add(const char *path, bool fsid_change_in_progress = (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_CHANGING_FSID_V2); - if (fsid_change_in_progress && !has_metadata_uuid) { - /* - * When we have an image which has CHANGING_FSID_V2 set it might - * belong to either a filesystem which has disks with completed - * fsid change or it might belong to fs with no UUID changes in - * effect, handle both. - */ - fs_devices = find_fsid_inprogress(disk_super); - if (!fs_devices) - fs_devices = find_fsid(disk_super->fsid, NULL); - + if (fsid_change_in_progress) { + if (!has_metadata_uuid) { + /* + * When we have an image which has CHANGING_FSID_V2 set + * it might belong to either a filesystem which has + * disks with completed fsid change or it might belong + * to fs with no UUID changes in effect, handle both. + */ + fs_devices = find_fsid_inprogress(disk_super); + if (!fs_devices) + fs_devices = find_fsid(disk_super->fsid, NULL); + } else { + fs_devices = find_fsid_changed(disk_super); + } } else if (has_metadata_uuid) { fs_devices = find_fsid(disk_super->fsid, disk_super->metadata_uuid);