user/sven/linux.git/drivers/md, branch v3.12.19

dm cache: fix access beyond end of origin device

2014-03-24T08:45:00Z

commit e893fba90c09f9b57fb97daae204ea9cc2c52fa5 upstream. In order to avoid wasting cache space a partial block at the end of the origin device is not cached. Unfortunately, the check for such a partial block at the end of the origin device was flawed. Fix accesses beyond the end of the origin device that occured due to attempted promotion of an undetected partial block by: - initializing the per bio data struct to allow cache_end_io to work properly - recognizing access to the partial block at the end of the origin device - avoiding out of bounds access to the discard bitset Otherwise, users can experience errors like the following: attempt to access beyond end of device dm-5: rw=0, want=20971520, limit=20971456 ... device-mapper: cache: promotion failed; couldn't copy block Signed-off-by: Heinz Mauelshagen Acked-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Jiri Slaby

dm cache: fix truncation bug when copying a block to/from >2TB fast device

2014-03-24T08:44:59Z

commit 8b9d96666529a979acf4825391efcc7c8a3e9f12 upstream. During demotion or promotion to a cache's >2TB fast device we must not truncate the cache block's associated sector to 32bits. The 32bit temporary result of from_cblock() caused a 32bit multiplication when calculating the sector of the fast device in issue_copy_real(). Use an intermediate 64bit type to store the 32bit from_cblock() to allow for proper 64bit multiplication. Here is an example of how this bug manifests on an ext4 filesystem: EXT4-fs error (device dm-0): ext4_mb_generate_buddy:756: group 17136, 32768 clusters in bitmap, 30688 in gd; block bitmap corrupt. JBD2: Spotted dirty metadata buffer (dev = dm-0, blocknr = 0). There's a risk of filesystem corruption in case of system crash. Signed-off-by: Heinz Mauelshagen Acked-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Jiri Slaby

dm space map metadata: fix refcount decrement below 0 which caused corruption

2014-03-24T08:44:59Z

commit cebc2de44d3bce53e46476e774126c298ca2c8a9 upstream. 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 Reported-by: edwillam1007@gmail.com Reported-by: Teng-Feng Yang Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Jiri Slaby

dm thin: fix the error path for the thin device constructor

2014-03-05T16:13:55Z

commit 1acacc0784aab45627b6009e0e9224886279ac0b upstream. dm_pool_close_thin_device() must be called if dm_set_target_max_io_len() fails in thin_ctr(). Otherwise __pool_destroy() will fail because the pool will still have an open thin device: device-mapper: thin metadata: attempt to close pmd when 1 device(s) are still open device-mapper: thin: __pool_destroy: dm_pool_metadata_close() failed. Also, must establish error code if failing thin_ctr() because the pool is in fail_io mode. Signed-off-by: Mike Snitzer Acked-by: Joe Thornber Signed-off-by: Jiri Slaby

dm thin: avoid metadata commit if a pool's thin devices haven't changed

2014-03-05T16:13:55Z

commit 4d1662a30dde6e545086fe0e8fd7e474c4e0b639 upstream. Commit 905e51b ("dm thin: commit outstanding data every second") introduced a periodic commit. This commit occurs regardless of whether any thin devices have made changes. Fix the periodic commit to check if any of a pool's thin devices have changed using dm_pool_changed_this_transaction(). Reported-by: Alexander Larsson Signed-off-by: Mike Snitzer Acked-by: Joe Thornber Signed-off-by: Jiri Slaby

dm mpath: fix stalls when handling invalid ioctls

2014-03-05T16:13:55Z

commit a1989b330093578ea5470bea0a00f940c444c466 upstream. An invalid ioctl will never be valid, irrespective of whether multipath has active paths or not. So for invalid ioctls we do not have to wait for multipath to activate any paths, but can rather return an error code immediately. This fix resolves numerous instances of: udevd[]: worker [] unexpectedly returned with status 0x0100 that have been seen during testing. Signed-off-by: Hannes Reinecke Signed-off-by: Mike Snitzer Signed-off-by: Jiri Slaby

md/raid5: Fix CPU hotplug callback registration

2014-02-22T21:32:29Z

commit 789b5e0315284463617e106baad360cb9e8db3ac upstream. Subsystems that want to register CPU hotplug callbacks, as well as perform initialization for the CPUs that are already online, often do it as shown below: get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); register_cpu_notifier(&foobar_cpu_notifier); put_online_cpus(); This is wrong, since it is prone to ABBA deadlocks involving the cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently with CPU hotplug operations). Interestingly, the raid5 code can actually prevent double initialization and hence can use the following simplified form of callback registration: register_cpu_notifier(&foobar_cpu_notifier); get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); put_online_cpus(); A hotplug operation that occurs between registering the notifier and calling get_online_cpus(), won't disrupt anything, because the code takes care to perform the memory allocations only once. So reorganize the code in raid5 this way to fix the deadlock with callback registration. Cc: linux-raid@vger.kernel.org Fixes: 36d1c6476be51101778882897b315bd928c8c7b5 Signed-off-by: Oleg Nesterov [Srivatsa: Fixed the unregister_cpu_notifier() deadlock, added the free_scratch_buffer() helper to condense code further and wrote the changelog.] Signed-off-by: Srivatsa S. Bhat Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

md/raid1: restore ability for check and repair to fix read errors.

2014-02-22T21:32:29Z

commit 1877db75589a895bbdc4c4c3f23558e57b521141 upstream. commit 30bc9b53878a9921b02e3b5bc4283ac1c6de102a md/raid1: fix bio handling problems in process_checks() Move the bio_reset() to a point before where BIO_UPTODATE is checked, so that check now always report that the bio is uptodate, even if it is not. This causes process_check() to sometimes treat read-errors as successful matches so the good data isn't written out. This patch preserves the flag until it is needed. Bug was introduced in 3.11, but backported to 3.10-stable (as it fixed an even worse bug). So suitable for any -stable since 3.10. Reported-and-tested-by: Michael Tokarev Fixed: 30bc9b53878a9921b02e3b5bc4283ac1c6de102a Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

dm sysfs: fix a module unload race

2014-02-13T21:50:22Z

commit 2995fa78e423d7193f3b57835f6c1c75006a0315 upstream. This reverts commit be35f48610 ("dm: wait until embedded kobject is released before destroying a device") and provides an improved fix. The kobject release code that calls the completion must be placed in a non-module file, otherwise there is a module unload race (if the process calling dm_kobject_release is preempted and the DM module unloaded after the completion is triggered, but before dm_kobject_release returns). To fix this race, this patch moves the completion code to dm-builtin.c which is always compiled directly into the kernel if BLK_DEV_DM is selected. The patch introduces a new dm_kobject_holder structure, its purpose is to keep the completion and kobject in one place, so that it can be accessed from non-module code without the need to export the layout of struct mapped_device to that code. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

dm space map metadata: fix bug in resizing of thin metadata

2014-02-13T21:50:18Z

commit fca028438fb903852beaf7c3fe1cd326651af57d upstream. 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 Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman