summaryrefslogtreecommitdiffstats
path: root/drivers/md/persistent-data/dm-space-map-metadata.c
Commit message (Collapse)AuthorAgeFilesLines
* dm space map metadata: fix sm_bootstrap_get_count()Joe Thornber2014-12-021-1/+3
| | | | | | | Must set 'result' accordingly rather than return it. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm space map metadata: fix sm_bootstrap_get_nr_blocks()Dan Carpenter2014-12-011-1/+3
| | | | | | | | | | | | | | | This function isn't right and it causes a static checker warning: drivers/md/dm-thin.c:3016 maybe_resize_data_dev() error: potentially using uninitialized 'sb_data_size'. It should set "*count" and return zero on success the same as the sm_metadata_get_nr_blocks() function does earlier. Fixes: 3241b1d3e0aa ('dm: add persistent data library') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm space map metadata: fix refcount decrement below 0 which caused corruptionJoe Thornber2014-03-071-21/+92
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This has been a relatively long-standing issue that wasn't nailed down until Teng-Feng Yang's meticulous bug report to dm-devel on 3/7/2014, see: http://www.redhat.com/archives/dm-devel/2014-March/msg00021.html From that report: "When decreasing the reference count of a metadata block with its reference count equals 3, we will call dm_btree_remove() to remove this enrty from the B+tree which keeps the reference count info in metadata device. The B+tree will try to rebalance the entry of the child nodes in each node it traversed, and the rebalance process contains the following steps. (1) Finding the corresponding children in current node (shadow_current(s)) (2) Shadow the children block (issue BOP_INC) (3) redistribute keys among children, and free children if necessary (issue BOP_DEC) Since the update of a metadata block's reference count could be recursive, we will stash these reference count update operations in smm->uncommitted and then process them in a FILO fashion. The problem is that step(3) could free the children which is created in step(2), so the BOP_DEC issued in step(3) will be carried out before the BOP_INC issued in step(2) since these BOPs will be processed in FILO fashion. Once the BOP_DEC from step(3) tries to decrease the reference count of newly shadow block, it will report failure for its reference equals 0 before decreasing. It looks like we can solve this issue by processing these BOPs in a FIFO fashion instead of FILO." Commit 5b564d80 ("dm space map: disallow decrementing a reference count below zero") changed the code to report an error for this temporary refcount decrement below zero. So what was previously a harmless invalid refcount became a hard failure due to the new error path: device-mapper: space map common: unable to decrement a reference count below 0 device-mapper: thin: 253:6: dm_thin_insert_block() failed: error = -22 device-mapper: thin: 253:6: switching pool to read-only mode This bug is in dm persistent-data code that is common to the DM thin and cache targets. So any users of those targets should apply this fix. Fix this by applying recursive space map operations in FIFO order rather than FILO. Resolves: https://bugzilla.kernel.org/show_bug.cgi?id=68801 Reported-by: Apollon Oikonomopoulos <apoikos@debian.org> Reported-by: edwillam1007@gmail.com Reported-by: Teng-Feng Yang <shinrairis@gmail.com> Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.13+
* dm thin: allow metadata space larger than supported to go unusedMike Snitzer2014-02-271-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It was always intended that a user could provide a thin metadata device that is larger than the max supported by the on-disk format. The extra space would just go unused. Unfortunately that never worked. If the user attempted to use a larger metadata device on creation they would get an error like the following: device-mapper: space map common: space map too large device-mapper: transaction manager: couldn't create metadata space map device-mapper: thin metadata: tm_create_with_sm failed device-mapper: table: 252:17: thin-pool: Error creating metadata object device-mapper: ioctl: error adding target to table Fix this by allowing the initial metadata space map creation to cap its size at the max number of blocks supported (DM_SM_METADATA_MAX_BLOCKS). get_metadata_dev_size() must also impose DM_SM_METADATA_MAX_BLOCKS (via THIN_METADATA_MAX_SECTORS), otherwise extending metadata would cap at THIN_METADATA_MAX_SECTORS_WARNING (which is larger than supported). Also, the calculation for THIN_METADATA_MAX_SECTORS didn't account for the sizeof the disk_bitmap_header. So the supported maximum metadata size is a bit smaller (reduced from 33423360 to 33292800 sectors). Lastly, remove the "excess space will not be used" warning message from get_metadata_dev_size(); it resulted in printing the warning multiple times. Factor out warn_if_metadata_device_too_big(), call it from pool_ctr() and maybe_resize_metadata_dev(). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* dm space map metadata: fix bug in resizing of thin metadataJoe Thornber2014-01-211-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This bug was introduced in commit 7e664b3dec431e ("dm space map metadata: fix extending the space map"). When extending a dm-thin metadata volume we: - Switch the space map into a simple bootstrap mode, which allocates all space linearly from the newly added space. - Add new bitmap entries for the new space - Increment the reference counts for those newly allocated bitmap entries - Commit changes to disk - Switch back out of bootstrap mode. But, the disk commit may allocate space itself, if so this fact will be lost when switching out of bootstrap mode. The bug exhibited itself as an error when the bitmap_root, with an erroneous ref count of 0, was subsequently decremented as part of a later disk commit. This would cause the disk commit to fail, and thinp to enter read_only mode. The metadata was not damaged (thin_check passed). The fix is to put the increments + commit into a loop, running until the commit has not allocated extra space. In practise this loop only runs twice. With this fix the following device mapper testsuite test passes: dmtest run --suite thin-provisioning -n thin_remove_works_after_resize Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # depends on commit 7e664b3dec431e
* dm space map metadata: fix extending the space mapJoe Thornber2014-01-071-5/+13
| | | | | | | | | | | | | | | | | | When extending a metadata space map we should do the first commit whilst still in bootstrap mode -- a mode where all blocks get allocated in the new area. That way the commit overhead is allocated from the newly added space. Otherwise we risk running out of space. With this fix, and the previous commit "dm space map common: make sure new space is used during extend", the following device mapper testsuite test passes: dmtest run --suite thin-provisioning -n /resize_metadata_no_io/ Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
* dm space map metadata: limit errors in sm_metadata_new_blockMike Snitzer2014-01-071-2/+2
| | | | | | | | The "unable to allocate new metadata block" error can be a particularly verbose error if there is a systemic issue with the metadata device. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
* dm space map metadata: return on failure in sm_metadata_new_blockMike Snitzer2013-12-101-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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:[<ffffffffa0331385>] [<ffffffffa0331385>] 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: [<ffffffffa0332020>] sm_ll_lookup_bitmap+0x40/0xa0 [dm_persistent_data] [<ffffffffa033304c>] sm_metadata_count_is_more_than_one+0x8c/0xc0 [dm_persistent_data] [<ffffffffa0333825>] dm_tm_shadow_block+0x65/0x110 [dm_persistent_data] [<ffffffffa0331b00>] sm_ll_mutate+0x80/0x300 [dm_persistent_data] [<ffffffffa0330e60>] ? set_ref_count+0x10/0x10 [dm_persistent_data] [<ffffffffa0331dba>] sm_ll_inc+0x1a/0x20 [dm_persistent_data] [<ffffffffa0332270>] sm_disk_new_block+0x60/0x80 [dm_persistent_data] [<ffffffff81520036>] ? down_write+0x16/0x40 [<ffffffffa001e5c4>] dm_pool_alloc_data_block+0x54/0x80 [dm_thin_pool] [<ffffffffa001b23c>] alloc_data_block+0x9c/0x130 [dm_thin_pool] [<ffffffffa001c27e>] provision_block+0x4e/0x180 [dm_thin_pool] [<ffffffffa001fe9a>] ? dm_thin_find_block+0x6a/0x110 [dm_thin_pool] [<ffffffffa001c57a>] process_bio+0x1ca/0x1f0 [dm_thin_pool] [<ffffffff8111e2ed>] ? mempool_free+0x8d/0xa0 [<ffffffffa001d755>] process_deferred_bios+0xc5/0x230 [dm_thin_pool] [<ffffffffa001d911>] do_worker+0x51/0x60 [dm_thin_pool] [<ffffffff81067872>] process_one_work+0x182/0x3b0 [<ffffffff81068c90>] worker_thread+0x120/0x3a0 [<ffffffff81068b70>] ? manage_workers+0x160/0x160 [<ffffffff8106eb2e>] kthread+0xce/0xe0 [<ffffffff8106ea60>] ? kthread_freezable_should_stop+0x70/0x70 [<ffffffff8152af6c>] ret_from_fork+0x7c/0xb0 [<ffffffff8106ea60>] ? kthread_freezable_should_stop+0x70/0x70 [<ffffffff8152af6c>] ret_from_fork+0x7c/0xb0 [<ffffffff8106ea60>] ? kthread_freezable_should_stop+0x70/0x70 Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Cc: stable@vger.kernel.org # v3.10+
* dm persistent metadata: add space map threshold callbackJoe Thornber2013-05-101-1/+76
| | | | | | | Add a threshold callback to dm persistent data space maps. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm persistent data: add threshold callback to space mapJoe Thornber2013-05-101-2/+4
| | | | | | | | | | | | 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 <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm persistent data: support space map resizingJoe Thornber2013-05-101-6/+32
| | | | | | | | | | | | Support extending a dm persistent data metadata space map. The extend itself is implemented by switching back to the boostrap allocator and pointing to the new space. The extra bitmap indexes are then allocated from the new space, and finally we switch back to the proper space map ops and tweak the reference counts. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm persistent data: fix error message typosJoe Thornber2013-05-101-4/+4
| | | | | | | Fix some typos in dm-space-map-metadata.c error messages. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm persistent data: improve improve space map block alloc failure messageJoe Thornber2012-12-211-1/+1
| | | | | | | | Improve space map error message when unable to allocate a new metadata block. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: add persistent data libraryJoe Thornber2011-10-311-0/+596
The persistent-data library offers a re-usable framework for the storage and management of on-disk metadata in device-mapper targets. It's used by the thin-provisioning target in the next patch and in an upcoming hierarchical storage target. For further information, please read Documentation/device-mapper/persistent-data.txt Signed-off-by: Joe Thornber <thornber@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
OpenPOWER on IntegriCloud