kernel/linux.git/drivers/md, branch v4.19.112

dm integrity: fix a deadlock due to offloading to an incorrect workqueue

2020-03-11T13:15:13+00:00

commit 53770f0ec5fd417429775ba006bc4abe14002335 upstream. If we need to perform synchronous I/O in dm_integrity_map_continue(), we must make sure that we are not in the map function - in order to avoid the deadlock due to bio queuing in generic_make_request. To avoid the deadlock, we offload the request to metadata_wq. However, metadata_wq also processes metadata updates for write requests. If there are too many requests that get offloaded to metadata_wq at the beginning of dm_integrity_map_continue, the workqueue metadata_wq becomes clogged and the system is incapable of processing any metadata updates. This causes a deadlock because all the requests that need to do metadata updates wait for metadata_wq to proceed and metadata_wq waits inside wait_and_add_new_range until some existing request releases its range lock (which doesn't happen because the range lock is released after metadata update). In order to fix the deadlock, we create a new workqueue offload_wq and offload requests to it - so that processing of offload_wq is independent from processing of metadata_wq. Fixes: 7eada909bfd7 ("dm: add integrity target") Cc: stable@vger.kernel.org # v4.12+ Reported-by: Heinz Mauelshagen Tested-by: Heinz Mauelshagen Signed-off-by: Heinz Mauelshagen Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm writecache: verify watermark during resume

2020-03-11T13:15:06+00:00

commit 41c526c5af46d4c4dab7f72c99000b7fac0b9702 upstream. Verify the watermark upon resume - so that if the target is reloaded with lower watermark, it will start the cleanup process immediately. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm: report suspended device during destroy

2020-03-11T13:15:05+00:00

commit adc0daad366b62ca1bce3e2958a40b0b71a8b8b3 upstream. The function dm_suspended returns true if the target is suspended. However, when the target is being suspended during unload, it returns false. An example where this is a problem: the test "!dm_suspended(wc->ti)" in writecache_writeback is not sufficient, because dm_suspended returns zero while writecache_suspend is in progress. As is, without an enhanced dm_suspended, simply switching from flush_workqueue to drain_workqueue still emits warnings: workqueue writecache-writeback: drain_workqueue() isn't complete after 10 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 100 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 200 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 300 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 400 tries writecache_suspend calls flush_workqueue(wc->writeback_wq) - this function flushes the current work. However, the workqueue may re-queue itself and flush_workqueue doesn't wait for re-queued works to finish. Because of this - the function writecache_writeback continues execution after the device was suspended and then concurrently with writecache_dtr, causing a crash in writecache_writeback. We must use drain_workqueue - that waits until the work and all re-queued works finish. As a prereq for switching to drain_workqueue, this commit fixes dm_suspended to return true after the presuspend hook and before the postsuspend hook - just like during a normal suspend. It allows simplifying the dm-integrity and dm-writecache targets so that they don't have to maintain suspended flags on their own. With this change use of drain_workqueue() can be used effectively. This change was tested with the lvm2 testsuite and cryptsetup testsuite and the are no regressions. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Reported-by: Corey Marthaler Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm cache: fix a crash due to incorrect work item cancelling

2020-03-11T13:15:05+00:00

commit 7cdf6a0aae1cccf5167f3f04ecddcf648b78e289 upstream. The crash can be reproduced by running the lvm2 testsuite test lvconvert-thin-external-cache.sh for several minutes, e.g.: while :; do make check T=shell/lvconvert-thin-external-cache.sh; done The crash happens in this call chain: do_waker -> policy_tick -> smq_tick -> end_hotspot_period -> clear_bitset -> memset -> __memset -- which accesses an invalid pointer in the vmalloc area. The work entry on the workqueue is executed even after the bitmap was freed. The problem is that cancel_delayed_work doesn't wait for the running work item to finish, so the work item can continue running and re-submitting itself even after cache_postsuspend. In order to make sure that the work item won't be running, we must use cancel_delayed_work_sync. Also, change flush_workqueue to drain_workqueue, so that if some work item submits itself or another work item, we are properly waiting for both of them. Fixes: c6b4fcbad044 ("dm: add cache target") Cc: stable@vger.kernel.org # v3.9 Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

bcache: explicity type cast in bset_bkey_last()

2020-02-24T07:34:53+00:00

[ Upstream commit 7c02b0055f774ed9afb6e1c7724f33bf148ffdc0 ] In bset.h, macro bset_bkey_last() is defined as, bkey_idx((struct bkey *) (i)->d, (i)->keys) Parameter i can be variable type of data structure, the macro always works once the type of struct i has member 'd' and 'keys'. bset_bkey_last() is also used in macro csum_set() to calculate the checksum of a on-disk data structure. When csum_set() is used to calculate checksum of on-disk bcache super block, the parameter 'i' data type is struct cache_sb_disk. Inside struct cache_sb_disk (also in struct cache_sb) the member keys is __u16 type. But bkey_idx() expects unsigned int (a 32bit width), so there is problem when sending parameters via stack to call bkey_idx(). Sparse tool from Intel 0day kbuild system reports this incompatible problem. bkey_idx() is part of user space API, so the simplest fix is to cast the (i)->keys to unsigned int type in macro bset_bkey_last(). Reported-by: kbuild test robot Signed-off-by: Coly Li Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

bcache: cached_dev_free needs to put the sb page

2020-02-24T07:34:51+00:00

[ Upstream commit e8547d42095e58bee658f00fef8e33d2a185c927 ] Same as cache device, the buffer page needs to be put while freeing cached_dev. Otherwise a page would be leaked every time a cached_dev is stopped. Signed-off-by: Liang Chen Signed-off-by: Christoph Hellwig Signed-off-by: Coly Li Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

bcache: add readahead cache policy options via sysfs interface

2020-02-11T12:34:08+00:00

commit 038ba8cc1bffc51250add4a9b9249d4331576d8f upstream. In year 2007 high performance SSD was still expensive, in order to save more space for real workload or meta data, the readahead I/Os for non-meta data was bypassed and not cached on SSD. In now days, SSD price drops a lot and people can find larger size SSD with more comfortable price. It is unncessary to alway bypass normal readahead I/Os to save SSD space for now. This patch adds options for readahead data cache policies via sysfs file /sys/block/bcache/readahead_cache_policy, the options are, - "all": cache all readahead data I/Os. - "meta-only": only cache meta data, and bypass other regular I/Os. If users want to make bcache continue to only cache readahead request for metadata and bypass regular data readahead, please set "meta-only" to this sysfs file. By default, bcache will back to cache all read- ahead requests now. Cc: stable@vger.kernel.org Signed-off-by: Coly Li Acked-by: Eric Wheeler Cc: Michael Lyle Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

dm writecache: fix incorrect flush sequence when doing SSD mode commit

2020-02-11T12:34:04+00:00

commit aa9509209c5ac2f0b35d01a922bf9ae072d0c2fc upstream. When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm: fix potential for q->make_request_fn NULL pointer

2020-02-11T12:34:04+00:00

commit 47ace7e012b9f7ad71d43ac9063d335ea3d6820b upstream. Move blk_queue_make_request() to dm.c:alloc_dev() so that q->make_request_fn is never NULL during the lifetime of a DM device (even one that is created without a DM table). Otherwise generic_make_request() will crash simply by doing: dmsetup create -n test mount /dev/dm-N /mnt While at it, move ->congested_data initialization out of dm.c:alloc_dev() and into the bio-based specific init method. Reported-by: Stefan Bader BugLink: https://bugs.launchpad.net/bugs/1860231 Fixes: ff36ab34583a ("dm: remove request-based logic from make_request_fn wrapper") Depends-on: c12c9a3c3860c ("dm: various cleanups to md->queue initialization code") Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm crypt: fix benbi IV constructor crash if used in authenticated mode

2020-02-11T12:34:04+00:00

commit 4ea9471fbd1addb25a4d269991dc724e200ca5b5 upstream. If benbi IV is used in AEAD construction, for example: cryptsetup luksFormat --cipher twofish-xts-benbi --key-size 512 --integrity=hmac-sha256 the constructor uses wrong skcipher function and crashes: BUG: kernel NULL pointer dereference, address: 00000014 ... EIP: crypt_iv_benbi_ctr+0x15/0x70 [dm_crypt] Call Trace: ? crypt_subkey_size+0x20/0x20 [dm_crypt] crypt_ctr+0x567/0xfc0 [dm_crypt] dm_table_add_target+0x15f/0x340 [dm_mod] Fix this by properly using crypt_aead_blocksize() in this case. Fixes: ef43aa38063a6 ("dm crypt: add cryptographic data integrity protection (authenticated encryption)") Cc: stable@vger.kernel.org # v4.12+ Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=941051 Reported-by: Jerad Simpson Signed-off-by: Milan Broz Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman