kernel/linux.git/drivers/md/persistent-data, branch v3.4.105

dm thin: fix discard corruption

2014-06-07T23:02:05+00:00

commit f046f89a99ccfd9408b94c653374ff3065c7edb3 upstream. Fix a bug in dm_btree_remove that could leave leaf values with incorrect reference counts. The effect of this was that removal of a shared block could result in the space maps thinking the block was no longer used. More concretely, if you have a thin device and a snapshot of it, sending a discard to a shared region of the thin could corrupt the snapshot. Thinp uses a 2-level nested btree to store it's mappings. This first level is indexed by thin device, and the second level by logical block. Often when we're removing an entry in this mapping tree we need to rebalance nodes, which can involve shadowing them, possibly creating a copy if the block is shared. If we do create a copy then children of that node need to have their reference counts incremented. In this way reference counts percolate down the tree as shared trees diverge. The rebalance functions were incrementing the children at the appropriate time, but they were always assuming the children were internal nodes. This meant the leaf values (in our case packed block/flags entries) were not being incremented. Signed-off-by: Joe Thornber Signed-off-by: Alasdair G Kergon [bwh: Backported to 3.2: bump target version numbers from 1.0.1 to 1.0.2] Signed-off-by: Ben Hutchings [xr: Backported to 3.4: bump target version numbers to 1.1.1] Signed-off-by: Rui Xiang Signed-off-by: Greg Kroah-Hartman

dm space map common: make sure new space is used during extend

2014-02-13T19:51:14+00:00

commit 12c91a5c2d2a8e8cc40a9552313e1e7b0a2d9ee3 upstream. When extending a low level space map we should update nr_blocks at the start so the new space is used for the index entries. Otherwise extend can fail, e.g.: sm_metadata_extend call sequence that fails: -> sm_ll_extend -> dm_tm_new_block -> dm_sm_new_block -> sm_bootstrap_new_block => returns -ENOSPC because smm->begin == smm->ll.nr_blocks Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm persistent data: rename node to btree_node

2013-01-17T16:50:51+00:00

commit 550929faf89e2e2cdb3e9945ea87d383989274cf upstream. This patch fixes a compilation failure on sparc32 by renaming struct node. struct node is already defined in include/linux/node.h. On sparc32, it happens to be included through other dependencies and persistent-data doesn't compile because of conflicting declarations. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon Signed-off-by: Greg Kroah-Hartman

dm persistent data: fix allocation failure in space map checker init

2012-07-16T16:04:26+00:00

commit b0239faaf87c38bb419c9264bf20817438ddc3a9 upstream. If CONFIG_DM_DEBUG_SPACE_MAPS is enabled and memory is fragmented and a sufficiently-large metadata device is used in a thin pool then the space map checker will fail to allocate the memory it requires. Switch from kmalloc to vmalloc to allow larger virtually contiguous allocations for the space map checker's internal count arrays. Reported-by: Vivek Goyal Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon Signed-off-by: Greg Kroah-Hartman

dm persistent data: handle space map checker creation failure

2012-07-16T16:04:26+00:00

commit 62662303e7f590fdfbb0070ab820a0ad4267c119 upstream. If CONFIG_DM_DEBUG_SPACE_MAPS is enabled and dm_sm_checker_create() fails, dm_tm_create_internal() would still return success even though it cleaned up all resources it was supposed to have created. This will lead to a kernel crash: general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC ... RIP: 0010:[] [] dm_bufio_get_block_size+0x9/0x20 Call Trace: [] dm_bm_block_size+0xe/0x10 [] sm_ll_init+0x78/0xd0 [] sm_ll_new_disk+0x16/0xa0 [] dm_sm_disk_create+0xfe/0x160 [] dm_pool_metadata_open+0x16e/0x6a0 [] pool_ctr+0x3f0/0x900 [] dm_table_add_target+0x195/0x450 [] table_load+0xe4/0x330 [] ctl_ioctl+0x15a/0x2c0 [] dm_ctl_ioctl+0x13/0x20 [] do_vfs_ioctl+0x98/0x560 [] sys_ioctl+0x91/0xa0 [] system_call_fastpath+0x16/0x1b Fix the space map checker code to return an appropriate ERR_PTR and have dm_sm_disk_create() and dm_tm_create_internal() check for it with IS_ERR. Reported-by: Vivek Goyal Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon Signed-off-by: Greg Kroah-Hartman

dm persistent data: fix shadow_info_leak on dm_tm_destroy

2012-07-16T16:04:26+00:00

commit 25d7cd6faa7ae6ed2565617c3ee2500ccb8a9f7f upstream. Cleanup the shadow table before destroying the transaction manager. Reference: leak was identified with kmemleak when running test_discard_random_sectors in the thinp-test-suite. Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon Signed-off-by: Greg Kroah-Hartman

dm persistent data: remove space map ref_count entries if redundant

2012-03-28T17:41:27+00:00

Save space by removing entries from the space map ref_count tree if they're no longer needed. Ref counts are stored in two places: a bitmap if the ref_count is below 3, or a btree of uint32_t if 3 or above. When a ref_count that was above 3 drops below we can remove it from the tree and save some metadata space. This removal was commented out before because I was unsure why this was causing under-populated btree nodes. Earlier patches have fixed this issue. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon

dm persistent data: remove redundant value_size arg from value_ptr

2012-03-28T17:41:25+00:00

Now that the value_size is held within every node of the btrees we can remove this argument from value_ptr(). For the last few months a BUG_ON has been checking this argument is the same as that held in the node. No issues were reported. So this is a safe change. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon

dm persistent data: fix btree rebalancing after remove

2012-03-28T17:41:23+00:00

When we remove an entry from a node we sometimes rebalance with it's two neighbours. This wasn't being done correctly; in some cases entries have to move all the way from the right neighbour to the left neighbour, or vice versa. This patch pretty much re-writes the balancing code to fix it. This code is barely used currently; only when you delete a thin device, and then only if you have hundreds of them in the same pool. Once we have discard support, which removes mappings, this will be used much more heavily. Signed-off-by: Joe Thornber Cc: stable@kernel.org Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon

device-mapper: using EXPORT_SYBOL in dm-space-map-checker.c needs export.h

2011-11-07T18:29:10+00:00

Reported-by: Witold Baryluk Signed-off-by: Stephen Rothwell Signed-off-by: Paul Gortmaker Signed-off-by: Linus Torvalds