linux/drivers/md/persistent-data, branch v3.12.10

dm thin: allow pool in read-only mode to transition to read-write mode

2013-12-20T15:49:05Z

commit 9b7aaa64f96f7ca280d75326fca42f42017b89ef upstream. A thin-pool may be in read-only mode because the pool's data or metadata space was exhausted. To allow for recovery, by adding more space to the pool, we must allow a pool to transition from PM_READ_ONLY to PM_WRITE mode. Otherwise, running out of space will render the pool permanently read-only. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm space map: disallow decrementing a reference count below zero

2013-12-20T15:49:04Z

commit 5b564d80f8bc21094c0cd2b19b679d983aabcc29 upstream. The old behaviour, returning -EINVAL if a ref_count of 0 would be decremented, was removed in commit f722063 ("dm space map: optimise sm_ll_dec and sm_ll_inc"). To fix this regression we return an error code from the mutator function pointer passed to sm_ll_mutate() and have dec_ref_count() return -EINVAL if the old ref_count is 0. Add a DMERR to reflect the potential seriousness of this error. Also, add missing dm_tm_unlock() to sm_ll_mutate()'s error path. With this fix the following dmts regression test now passes: dmtest run --suite cache -n /metadata_use_kernel/ The next patch fixes the higher-level dm-array code that exposed this regression. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm space map metadata: return on failure in sm_metadata_new_block

2013-12-20T15:49:04Z

commit f62b6b8f498658a9d537c7d380e9966f15e1b2a1 upstream. 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 Signed-off-by: Greg Kroah-Hartman

dm array: fix a reference counting bug in shadow_ablock

2013-12-20T15:49:04Z

commit ed9571f0cf1fe09d3506302610f3ccdfa1d22c4a upstream. An old array block could have its reference count decremented below zero when it is being replaced in the btree by a new array block. The fix is to increment the old ablock's reference count just before inserting a new ablock into the btree. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm array: fix bug in growing array

2013-12-04T19:05:27Z

commit 9c1d4de56066e4d6abc66ec188faafd7b303fb08 upstream. Entries would be lost if the old tail block was partially filled. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm space map: optimise sm_ll_dec and sm_ll_inc

2013-08-23T13:02:14Z

Prior to this patch these methods did a lookup followed by an insert. Instead they now call a common mutate function that adjusts the value according to a callback function. This avoids traversing the data structures twice and hence improves performance. Also factor out sm_ll_lookup_big_ref_count() for use by both sm_ll_lookup() and sm_ll_mutate(). Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon

dm btree: prefetch child nodes when walking tree for a dm_btree_del

2013-08-23T13:02:14Z

dm-btree now takes advantage of dm-bufio's ability to prefetch data via dm_bm_prefetch(). Prior to this change many btree node visits were causing a synchronous read. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon

dm btree: use pop_frame in dm_btree_del to cleanup code

2013-08-23T13:02:14Z

Remove a visited leaf straight away from the stack, rather than marking all it's children as visited and letting it get removed on the next iteration. May also offer a micro optimisation in dm_btree_del. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon

dm persistent metadata: add space map threshold callback

2013-05-10T13:37:20Z

Add a threshold callback to dm persistent data space maps. Signed-off-by: Joe Thornber Signed-off-by: Alasdair G Kergon

dm persistent data: add threshold callback to space map

2013-05-10T13:37:20Z

Add a threshold callback function to the persistent data space map interface for a subsequent patch to use. dm-thin and dm-cache are interested in knowing when they're getting low on metadata or data blocks. This patch introduces a new method for registering a callback against a threshold. Signed-off-by: Joe Thornber Signed-off-by: Alasdair G Kergon