From f62b6b8f498658a9d537c7d380e9966f15e1b2a1 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Mon, 2 Dec 2013 16:47:01 -0500 Subject: [PATCH] dm space map metadata: return on failure in sm_metadata_new_block Commit 2fc48021f4afdd109b9e52b6eef5db89ca80bac7 ("dm persistent metadata: add space map threshold callback") introduced a regression to the metadata block allocation path that resulted in errors being ignored. This regression was uncovered by running the following device-mapper-test-suite test: dmtest run --suite thin-provisioning -n /exhausting_metadata_space_causes_fail_mode/ The ignored error codes in sm_metadata_new_block() could crash the kernel through use of either the dm-thin or dm-cache targets, e.g.: device-mapper: thin: 253:4: reached low water mark for metadata device: sending event. device-mapper: space map metadata: unable to allocate new metadata block general protection fault: 0000 [#1] SMP ... Workqueue: dm-thin do_worker [dm_thin_pool] task: ffff880035ce2ab0 ti: ffff88021a054000 task.ti: ffff88021a054000 RIP: 0010:[] [] metadata_ll_load_ie+0x15/0x30 [dm_persistent_data] RSP: 0018:ffff88021a055a68 EFLAGS: 00010202 RAX: 003fc8243d212ba0 RBX: ffff88021a780070 RCX: ffff88021a055a78 RDX: ffff88021a055a78 RSI: 0040402222a92a80 RDI: ffff88021a780070 RBP: ffff88021a055a68 R08: ffff88021a055ba4 R09: 0000000000000010 R10: 0000000000000000 R11: 00000002a02e1000 R12: ffff88021a055ad4 R13: 0000000000000598 R14: ffffffffa0338470 R15: ffff88021a055ba4 FS: 0000000000000000(0000) GS:ffff88033fca0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007f467c0291b8 CR3: 0000000001a0b000 CR4: 00000000000007e0 Stack: ffff88021a055ab8 ffffffffa0332020 ffff88021a055b30 0000000000000001 ffff88021a055b30 0000000000000000 ffff88021a055b18 0000000000000000 ffff88021a055ba4 ffff88021a055b98 ffff88021a055ae8 ffffffffa033304c Call Trace: [] sm_ll_lookup_bitmap+0x40/0xa0 [dm_persistent_data] [] sm_metadata_count_is_more_than_one+0x8c/0xc0 [dm_persistent_data] [] dm_tm_shadow_block+0x65/0x110 [dm_persistent_data] [] sm_ll_mutate+0x80/0x300 [dm_persistent_data] [] ? set_ref_count+0x10/0x10 [dm_persistent_data] [] sm_ll_inc+0x1a/0x20 [dm_persistent_data] [] sm_disk_new_block+0x60/0x80 [dm_persistent_data] [] ? down_write+0x16/0x40 [] dm_pool_alloc_data_block+0x54/0x80 [dm_thin_pool] [] alloc_data_block+0x9c/0x130 [dm_thin_pool] [] provision_block+0x4e/0x180 [dm_thin_pool] [] ? dm_thin_find_block+0x6a/0x110 [dm_thin_pool] [] process_bio+0x1ca/0x1f0 [dm_thin_pool] [] ? mempool_free+0x8d/0xa0 [] process_deferred_bios+0xc5/0x230 [dm_thin_pool] [] do_worker+0x51/0x60 [dm_thin_pool] [] process_one_work+0x182/0x3b0 [] worker_thread+0x120/0x3a0 [] ? manage_workers+0x160/0x160 [] kthread+0xce/0xe0 [] ? kthread_freezable_should_stop+0x70/0x70 [] ret_from_fork+0x7c/0xb0 [] ? kthread_freezable_should_stop+0x70/0x70 [] ret_from_fork+0x7c/0xb0 [] ? kthread_freezable_should_stop+0x70/0x70 Signed-off-by: Mike Snitzer Acked-by: Joe Thornber Cc: stable@vger.kernel.org # v3.10+ --- drivers/md/persistent-data/dm-space-map-metadata.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/md/persistent-data/dm-space-map-metadata.c b/drivers/md/persistent-data/dm-space-map-metadata.c index 1c959684caef..58fc1eef7499 100644 --- a/drivers/md/persistent-data/dm-space-map-metadata.c +++ b/drivers/md/persistent-data/dm-space-map-metadata.c @@ -384,12 +384,16 @@ static int sm_metadata_new_block(struct dm_space_map *sm, dm_block_t *b) struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm); int r = sm_metadata_new_block_(sm, b); - if (r) + if (r) { DMERR("unable to allocate new metadata block"); + return r; + } r = sm_metadata_get_nr_free(sm, &count); - if (r) + if (r) { DMERR("couldn't get free block count"); + return r; + } check_threshold(&smm->threshold, count); -- 2.20.1