linux/drivers/md, branch v3.4.78

md/raid10: fix two bugs in handling of known-bad-blocks.

2014-01-29T13:10:42Z

commit b50c259e25d9260b9108dc0c2964c26e5ecbe1c1 upstream. If we discover a bad block when reading we split the request and potentially read some of it from a different device. The code path of this has two bugs in RAID10. 1/ we get a spin_lock with _irq, but unlock without _irq!! 2/ The calculation of 'sectors_handled' is wrong, as can be clearly seen by comparison with raid1.c This leads to at least 2 warnings and a probable crash is a RAID10 ever had known bad blocks. Fixes: 856e08e23762dfb92ffc68fd0a8d228f9e152160 Reported-by: Damian Nowak URL: https://bugzilla.kernel.org/show_bug.cgi?id=68181 Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

md/raid10: fix bug when raid10 recovery fails to recover a block.

2014-01-29T13:10:42Z

commit e8b849158508565e0cd6bc80061124afc5879160 upstream. commit e875ecea266a543e643b19e44cf472f1412708f9 md/raid10 record bad blocks as needed during recovery. added code to the "cannot recover this block" path to record a bad block rather than fail the whole recovery. Unfortunately this new case was placed *after* r10bio was freed rather than *before*, yet it still uses r10bio. This is will crash with a null dereference. So move the freeing of r10bio down where it is safe. Fixes: e875ecea266a543e643b19e44cf472f1412708f9 Reported-by: Damian Nowak URL: https://bugzilla.kernel.org/show_bug.cgi?id=68181 Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

dm table: fail dm_table_create on dm_round_up overflow

2013-12-20T15:34:20Z

commit 5b2d06576c5410c10d95adfd5c4d8b24de861d87 upstream. The dm_round_up function may overflow to zero. In this case, dm_table_create() must fail rather than go on to allocate an empty array with alloc_targets(). This fixes a possible memory corruption that could be caused by passing too large a number in "param->target_count". Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm delay: fix a possible deadlock due to shared workqueue

2013-12-20T15:34:20Z

commit 718822c1c112dc99e0c72c8968ee1db9d9d910f0 upstream. The dm-delay target uses a shared workqueue for multiple instances. This can cause deadlock if two or more dm-delay targets are stacked on the top of each other. This patch changes dm-delay to use a per-instance workqueue. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm bufio: initialize read-only module parameters

2013-12-20T15:34:20Z

commit 4cb57ab4a2e61978f3a9b7d4f53988f30d61c27f upstream. Some module parameters in dm-bufio are read-only. These parameters inform the user about memory consumption. They are not supposed to be changed by the user. However, despite being read-only, these parameters can be set on modprobe or insmod command line, for example: modprobe dm-bufio current_allocated_bytes=12345 The kernel doesn't expect that these variables can be non-zero at module initialization and if the user sets them, it results in BUG. This patch initializes the variables in the module init routine, so that user-supplied values are ignored. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm: fix truncated status strings

2013-12-08T15:29:43Z

commit fd7c092e711ebab55b2688d3859d95dfd0301f73 upstream. Avoid returning a truncated table or status string instead of setting the DM_BUFFER_FULL_FLAG when the last target of a table fills the buffer. When processing a table or status request, the function retrieve_status calls ti->type->status. If ti->type->status returns non-zero, retrieve_status assumes that the buffer overflowed and sets DM_BUFFER_FULL_FLAG. However, targets don't return non-zero values from their status method on overflow. Most targets returns always zero. If a buffer overflow happens in a target that is not the last in the table, it gets noticed during the next iteration of the loop in retrieve_status; but if a buffer overflow happens in the last target, it goes unnoticed and erroneously truncated data is returned. In the current code, the targets behave in the following way: * dm-crypt returns -ENOMEM if there is not enough space to store the key, but it returns 0 on all other overflows. * dm-thin returns errors from the status method if a disk error happened. This is incorrect because retrieve_status doesn't check the error code, it assumes that all non-zero values mean buffer overflow. * all the other targets always return 0. This patch changes the ti->type->status function to return void (because most targets don't use the return code). Overflow is detected in retrieve_status: if the status method fills up the remaining space completely, it is assumed that buffer overflow happened. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon Signed-off-by: Greg Kroah-Hartman

md: fix calculation of stacking limits on level change.

2013-12-04T18:50:33Z

commit 02e5f5c0a0f726e66e3d8506ea1691e344277969 upstream. The various ->run routines of md personalities assume that the 'queue' has been initialised by the blk_set_stacking_limits() call in md_alloc(). However when the level is changed (by level_store()) the ->run routine for the new level is called for an array which has already had the stacking limits modified. This can result in incorrect final settings. So call blk_set_stacking_limits() before ->run in level_store(). A specific consequence of this bug is that it causes discard_granularity to be set incorrectly when reshaping a RAID4 to a RAID0. This is suitable for any -stable kernel since 3.3 in which blk_set_stacking_limits() was introduced. Reported-and-tested-by: "Baldysiak, Pawel" Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

dm: allocate buffer for messages with small number of arguments using GFP_NOIO

2013-12-04T18:50:31Z

commit f36afb3957353d2529cb2b00f78fdccd14fc5e9c upstream. dm-mpath and dm-thin must process messages even if some device is suspended, so we allocate argv buffer with GFP_NOIO. These messages have a small fixed number of arguments. On the other hand, dm-switch needs to process bulk data using messages so excessive use of GFP_NOIO could cause trouble. The patch also lowers the default number of arguments from 64 to 8, so that there is smaller load on GFP_NOIO allocations. Signed-off-by: Mikulas Patocka Acked-by: Alasdair G Kergon Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

md: Fix skipping recovery for read-only arrays.

2013-11-13T03:01:48Z

commit 61e4947c99c4494336254ec540c50186d186150b upstream. Since: commit 7ceb17e87bde79d285a8b988cfed9eaeebe60b86 md: Allow devices to be re-added to a read-only array. spares are activated on a read-only array. In case of raid1 and raid10 personalities it causes that not-in-sync devices are marked in-sync without checking if recovery has been finished. If a read-only array is degraded and one of its devices is not in-sync (because the array has been only partially recovered) recovery will be skipped. This patch adds checking if recovery has been finished before marking a device in-sync for raid1 and raid10 personalities. In case of raid5 personality such condition is already present (at raid5.c:6029). Bug was introduced in 3.10 and causes data corruption. Signed-off-by: Pawel Baldysiak Signed-off-by: Lukasz Dorau Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

dm snapshot: fix data corruption

2013-11-04T12:23:42Z

commit e9c6a182649f4259db704ae15a91ac820e63b0ca upstream. This patch fixes a particular type of data corruption that has been encountered when loading a snapshot's metadata from disk. When we allocate a new chunk in persistent_prepare, we increment ps->next_free and we make sure that it doesn't point to a metadata area by further incrementing it if necessary. When we load metadata from disk on device activation, ps->next_free is positioned after the last used data chunk. However, if this last used data chunk is followed by a metadata area, ps->next_free is positioned erroneously to the metadata area. A newly-allocated chunk is placed at the same location as the metadata area, resulting in data or metadata corruption. This patch changes the code so that ps->next_free skips the metadata area when metadata are loaded in function read_exceptions. The patch also moves a piece of code from persistent_prepare_exception to a separate function skip_metadata to avoid code duplication. CVE-2013-4299 Signed-off-by: Mikulas Patocka Cc: Mike Snitzer Signed-off-by: Alasdair G Kergon Signed-off-by: Greg Kroah-Hartman