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* dm bufio: fix deadlock with loop deviceJunxiao Bi2019-07-261-3/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | | | commit bd293d071ffe65e645b4d8104f9d8fe15ea13862 upstream. When thin-volume is built on loop device, if available memory is low, the following deadlock can be triggered: One process P1 allocates memory with GFP_FS flag, direct alloc fails, memory reclaim invokes memory shrinker in dm_bufio, dm_bufio_shrink_scan() runs, mutex dm_bufio_client->lock is acquired, then P1 waits for dm_buffer IO to complete in __try_evict_buffer(). But this IO may never complete if issued to an underlying loop device that forwards it using direct-IO, which allocates memory using GFP_KERNEL (see: do_blockdev_direct_IO()). If allocation fails, memory reclaim will invoke memory shrinker in dm_bufio, dm_bufio_shrink_scan() will be invoked, and since the mutex is already held by P1 the loop thread will hang, and IO will never complete. Resulting in ABBA deadlock. Cc: stable@vger.kernel.org Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm zoned: fix zone state management raceDamien Le Moal2019-07-262-28/+24Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3b8cafdd5436f9298b3bf6eb831df5eef5ee82b6 upstream. dm-zoned uses the zone flag DMZ_ACTIVE to indicate that a zone of the backend device is being actively read or written and so cannot be reclaimed. This flag is set as long as the zone atomic reference counter is not 0. When this atomic is decremented and reaches 0 (e.g. on BIO completion), the active flag is cleared and set again whenever the zone is reused and BIO issued with the atomic counter incremented. These 2 operations (atomic inc/dec and flag set/clear) are however not always executed atomically under the target metadata mutex lock and this causes the warning: WARN_ON(!test_bit(DMZ_ACTIVE, &zone->flags)); in dmz_deactivate_zone() to be displayed. This problem is regularly triggered with xfstests generic/209, generic/300, generic/451 and xfs/077 with XFS being used as the file system on the dm-zoned target device. Similarly, xfstests ext4/303, ext4/304, generic/209 and generic/300 trigger the warning with ext4 use. This problem can be easily fixed by simply removing the DMZ_ACTIVE flag and managing the "ACTIVE" state by directly looking at the reference counter value. To do so, the functions dmz_activate_zone() and dmz_deactivate_zone() are changed to inline functions respectively calling atomic_inc() and atomic_dec(), while the dmz_is_active() macro is changed to an inline function calling atomic_read(). Fixes: 3b1a94c88b79 ("dm zoned: drive-managed zoned block device target") Cc: stable@vger.kernel.org Reported-by: Masato Suzuki <masato.suzuki@wdc.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* raid5-cache: Need to do start() part job after adding journal deviceXiao Ni2019-07-261-2/+9
| | | | | | | | | | | | | | | | | | | | | commit d9771f5ec46c282d518b453c793635dbdc3a2a94 upstream. commit d5d885fd514f ("md: introduce new personality funciton start()") splits the init job to two parts. The first part run() does the jobs that do not require the md threads. The second part start() does the jobs that require the md threads. Now it just does run() in adding new journal device. It needs to do the second part start() too. Fixes: d5d885fd514f ("md: introduce new personality funciton start()") Cc: stable@vger.kernel.org #v4.9+ Reported-by: Michal Soltys <soltys@ziu.info> Signed-off-by: Xiao Ni <xni@redhat.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bcache: destroy dc->writeback_write_wq if failed to create dc->writeback_threadColy Li2019-07-261-0/+1
| | | | | | | | | | | | | | | | | | commit f54d801dda14942dbefa00541d10603015b7859c upstream. Commit 9baf30972b55 ("bcache: fix for gc and write-back race") added a new work queue dc->writeback_write_wq, but forgot to destroy it in the error condition when creating dc->writeback_thread failed. This patch destroys dc->writeback_write_wq if kthread_create() returns error pointer to dc->writeback_thread, then a memory leak is avoided. Fixes: 9baf30972b55 ("bcache: fix for gc and write-back race") Signed-off-by: Coly Li <colyli@suse.de> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bcache: fix mistaken sysfs entry for io_error counterColy Li2019-07-261-2/+2
| | | | | | | | | | | | | | | | | commit 5461999848e0462c14f306a62923d22de820a59c upstream. In bch_cached_dev_files[] from driver/md/bcache/sysfs.c, sysfs_errors is incorrectly inserted in. The correct entry should be sysfs_io_errors. This patch fixes the problem and now I/O errors of cached device can be read from /sys/block/bcache<N>/bcache/io_errors. Fixes: c7b7bd07404c5 ("bcache: add io_disable to struct cached_dev") Signed-off-by: Coly Li <colyli@suse.de> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bcache: ignore read-ahead request failure on backing deviceColy Li2019-07-261-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 578df99b1b0531d19af956530fe4da63d01a1604 upstream. When md raid device (e.g. raid456) is used as backing device, read-ahead requests on a degrading and recovering md raid device might be failured immediately by md raid code, but indeed this md raid array can still be read or write for normal I/O requests. Therefore such failed read-ahead request are not real hardware failure. Further more, after degrading and recovering accomplished, read-ahead requests will be handled by md raid array again. For such condition, I/O failures of read-ahead requests don't indicate real health status (because normal I/O still be served), they should not be counted into I/O error counter dc->io_errors. Since there is no simple way to detect whether the backing divice is a md raid device, this patch simply ignores I/O failures for read-ahead bios on backing device, to avoid bogus backing device failure on a degrading md raid array. Suggested-and-tested-by: Thorsten Knabe <linux@thorsten-knabe.de> Signed-off-by: Coly Li <colyli@suse.de> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bcache: Revert "bcache: free heap cache_set->flush_btree in bch_journal_free"Coly Li2019-07-261-1/+0Star
| | | | | | | | | | | | | | | | | | commit ba82c1ac1667d6efb91a268edb13fc9cdaecec9b upstream. This reverts commit 6268dc2c4703aabfb0b35681be709acf4c2826c6. This patch depends on commit c4dc2497d50d ("bcache: fix high CPU occupancy during journal") which is reverted in previous patch. So revert this one too. Fixes: 6268dc2c4703 ("bcache: free heap cache_set->flush_btree in bch_journal_free") Signed-off-by: Coly Li <colyli@suse.de> Cc: stable@vger.kernel.org Cc: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bcache: Revert "bcache: fix high CPU occupancy during journal"Coly Li2019-07-263-36/+15Star
| | | | | | | | | | | | | | | | | | | commit 249a5f6da57c28a903c75d81505d58ec8c10030d upstream. This reverts commit c4dc2497d50d9c6fb16aa0d07b6a14f3b2adb1e0. This patch enlarges a race between normal btree flush code path and flush_btree_write(), which causes deadlock when journal space is exhausted. Reverts this patch makes the race window from 128 btree nodes to only 1 btree nodes. Fixes: c4dc2497d50d ("bcache: fix high CPU occupancy during journal") Signed-off-by: Coly Li <colyli@suse.de> Cc: stable@vger.kernel.org Cc: Tang Junhui <tang.junhui.linux@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "bcache: set CACHE_SET_IO_DISABLE in bch_cached_dev_error()"Coly Li2019-07-261-17/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | commit 695277f16b3a102fcc22c97fdf2de77c7b19f0b3 upstream. This reverts commit 6147305c73e4511ca1a975b766b97a779d442567. Although this patch helps the failed bcache device to stop faster when too many I/O errors detected on corresponding cached device, setting CACHE_SET_IO_DISABLE bit to cache set c->flags was not a good idea. This operation will disable all I/Os on cache set, which means other attached bcache devices won't work neither. Without this patch, the failed bcache device can also be stopped eventually if internal I/O accomplished (e.g. writeback). Therefore here I revert it. Fixes: 6147305c73e4 ("bcache: set CACHE_SET_IO_DISABLE in bch_cached_dev_error()") Reported-by: Yong Li <mr.liyong@qq.com> Signed-off-by: Coly Li <colyli@suse.de> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bcache: fix potential deadlock in cached_def_free()Coly Li2019-07-262-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 7e865eba00a3df2dc8c4746173a8ca1c1c7f042e ] When enable lockdep and reboot system with a writeback mode bcache device, the following potential deadlock warning is reported by lockdep engine. [ 101.536569][ T401] kworker/2:2/401 is trying to acquire lock: [ 101.538575][ T401] 00000000bbf6e6c7 ((wq_completion)bcache_writeback_wq){+.+.}, at: flush_workqueue+0x87/0x4c0 [ 101.542054][ T401] [ 101.542054][ T401] but task is already holding lock: [ 101.544587][ T401] 00000000f5f305b3 ((work_completion)(&cl->work)#2){+.+.}, at: process_one_work+0x21e/0x640 [ 101.548386][ T401] [ 101.548386][ T401] which lock already depends on the new lock. [ 101.548386][ T401] [ 101.551874][ T401] [ 101.551874][ T401] the existing dependency chain (in reverse order) is: [ 101.555000][ T401] [ 101.555000][ T401] -> #1 ((work_completion)(&cl->work)#2){+.+.}: [ 101.557860][ T401] process_one_work+0x277/0x640 [ 101.559661][ T401] worker_thread+0x39/0x3f0 [ 101.561340][ T401] kthread+0x125/0x140 [ 101.562963][ T401] ret_from_fork+0x3a/0x50 [ 101.564718][ T401] [ 101.564718][ T401] -> #0 ((wq_completion)bcache_writeback_wq){+.+.}: [ 101.567701][ T401] lock_acquire+0xb4/0x1c0 [ 101.569651][ T401] flush_workqueue+0xae/0x4c0 [ 101.571494][ T401] drain_workqueue+0xa9/0x180 [ 101.573234][ T401] destroy_workqueue+0x17/0x250 [ 101.575109][ T401] cached_dev_free+0x44/0x120 [bcache] [ 101.577304][ T401] process_one_work+0x2a4/0x640 [ 101.579357][ T401] worker_thread+0x39/0x3f0 [ 101.581055][ T401] kthread+0x125/0x140 [ 101.582709][ T401] ret_from_fork+0x3a/0x50 [ 101.584592][ T401] [ 101.584592][ T401] other info that might help us debug this: [ 101.584592][ T401] [ 101.588355][ T401] Possible unsafe locking scenario: [ 101.588355][ T401] [ 101.590974][ T401] CPU0 CPU1 [ 101.592889][ T401] ---- ---- [ 101.594743][ T401] lock((work_completion)(&cl->work)#2); [ 101.596785][ T401] lock((wq_completion)bcache_writeback_wq); [ 101.600072][ T401] lock((work_completion)(&cl->work)#2); [ 101.602971][ T401] lock((wq_completion)bcache_writeback_wq); [ 101.605255][ T401] [ 101.605255][ T401] *** DEADLOCK *** [ 101.605255][ T401] [ 101.608310][ T401] 2 locks held by kworker/2:2/401: [ 101.610208][ T401] #0: 00000000cf2c7d17 ((wq_completion)events){+.+.}, at: process_one_work+0x21e/0x640 [ 101.613709][ T401] #1: 00000000f5f305b3 ((work_completion)(&cl->work)#2){+.+.}, at: process_one_work+0x21e/0x640 [ 101.617480][ T401] [ 101.617480][ T401] stack backtrace: [ 101.619539][ T401] CPU: 2 PID: 401 Comm: kworker/2:2 Tainted: G W 5.2.0-rc4-lp151.20-default+ #1 [ 101.623225][ T401] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018 [ 101.627210][ T401] Workqueue: events cached_dev_free [bcache] [ 101.629239][ T401] Call Trace: [ 101.630360][ T401] dump_stack+0x85/0xcb [ 101.631777][ T401] print_circular_bug+0x19a/0x1f0 [ 101.633485][ T401] __lock_acquire+0x16cd/0x1850 [ 101.635184][ T401] ? __lock_acquire+0x6a8/0x1850 [ 101.636863][ T401] ? lock_acquire+0xb4/0x1c0 [ 101.638421][ T401] ? find_held_lock+0x34/0xa0 [ 101.640015][ T401] lock_acquire+0xb4/0x1c0 [ 101.641513][ T401] ? flush_workqueue+0x87/0x4c0 [ 101.643248][ T401] flush_workqueue+0xae/0x4c0 [ 101.644832][ T401] ? flush_workqueue+0x87/0x4c0 [ 101.646476][ T401] ? drain_workqueue+0xa9/0x180 [ 101.648303][ T401] drain_workqueue+0xa9/0x180 [ 101.649867][ T401] destroy_workqueue+0x17/0x250 [ 101.651503][ T401] cached_dev_free+0x44/0x120 [bcache] [ 101.653328][ T401] process_one_work+0x2a4/0x640 [ 101.655029][ T401] worker_thread+0x39/0x3f0 [ 101.656693][ T401] ? process_one_work+0x640/0x640 [ 101.658501][ T401] kthread+0x125/0x140 [ 101.660012][ T401] ? kthread_create_worker_on_cpu+0x70/0x70 [ 101.661985][ T401] ret_from_fork+0x3a/0x50 [ 101.691318][ T401] bcache: bcache_device_free() bcache0 stopped Here is how the above potential deadlock may happen in reboot/shutdown code path, 1) bcache_reboot() is called firstly in the reboot/shutdown code path, then in bcache_reboot(), bcache_device_stop() is called. 2) bcache_device_stop() sets BCACHE_DEV_CLOSING on d->falgs, then call closure_queue(&d->cl) to invoke cached_dev_flush(). And in turn cached_dev_flush() calls cached_dev_free() via closure_at() 3) In cached_dev_free(), after stopped writebach kthread dc->writeback_thread, the kwork dc->writeback_write_wq is stopping by destroy_workqueue(). 4) Inside destroy_workqueue(), drain_workqueue() is called. Inside drain_workqueue(), flush_workqueue() is called. Then wq->lockdep_map is acquired by lock_map_acquire() in flush_workqueue(). After the lock acquired the rest part of flush_workqueue() just wait for the workqueue to complete. 5) Now we look back at writeback thread routine bch_writeback_thread(), in the main while-loop, write_dirty() is called via continue_at() in read_dirty_submit(), which is called via continue_at() in while-loop level called function read_dirty(). Inside write_dirty() it may be re-called on workqueeu dc->writeback_write_wq via continue_at(). It means when the writeback kthread is stopped in cached_dev_free() there might be still one kworker queued on dc->writeback_write_wq to execute write_dirty() again. 6) Now this kworker is scheduled on dc->writeback_write_wq to run by process_one_work() (which is called by worker_thread()). Before calling the kwork routine, wq->lockdep_map is acquired. 7) But wq->lockdep_map is acquired already in step 4), so a A-A lock (lockdep terminology) scenario happens. Indeed on multiple cores syatem, the above deadlock is very rare to happen, just as the code comments in process_one_work() says, 2263 * AFAICT there is no possible deadlock scenario between the 2264 * flush_work() and complete() primitives (except for single-threaded 2265 * workqueues), so hiding them isn't a problem. But it is still good to fix such lockdep warning, even no one running bcache on single core system. The fix is simple. This patch solves the above potential deadlock by, - Do not destroy workqueue dc->writeback_write_wq in cached_dev_free(). - Flush and destroy dc->writeback_write_wq in writebach kthread routine bch_writeback_thread(), where after quit the thread main while-loop and before cached_dev_put() is called. By this fix, dc->writeback_write_wq will be stopped and destroy before the writeback kthread stopped, so the chance for a A-A locking on wq->lockdep_map is disappeared, such A-A deadlock won't happen any more. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bcache: check c->gc_thread by IS_ERR_OR_NULL in cache_set_flush()Coly Li2019-07-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit b387e9b58679c60f5b1e4313939bd4878204fc37 ] When system memory is in heavy pressure, bch_gc_thread_start() from run_cache_set() may fail due to out of memory. In such condition, c->gc_thread is assigned to -ENOMEM, not NULL pointer. Then in following failure code path bch_cache_set_error(), when cache_set_flush() gets called, the code piece to stop c->gc_thread is broken, if (!IS_ERR_OR_NULL(c->gc_thread)) kthread_stop(c->gc_thread); And KASAN catches such NULL pointer deference problem, with the warning information: [ 561.207881] ================================================================== [ 561.207900] BUG: KASAN: null-ptr-deref in kthread_stop+0x3b/0x440 [ 561.207904] Write of size 4 at addr 000000000000001c by task kworker/15:1/313 [ 561.207913] CPU: 15 PID: 313 Comm: kworker/15:1 Tainted: G W 5.0.0-vanilla+ #3 [ 561.207916] Hardware name: Lenovo ThinkSystem SR650 -[7X05CTO1WW]-/-[7X05CTO1WW]-, BIOS -[IVE136T-2.10]- 03/22/2019 [ 561.207935] Workqueue: events cache_set_flush [bcache] [ 561.207940] Call Trace: [ 561.207948] dump_stack+0x9a/0xeb [ 561.207955] ? kthread_stop+0x3b/0x440 [ 561.207960] ? kthread_stop+0x3b/0x440 [ 561.207965] kasan_report+0x176/0x192 [ 561.207973] ? kthread_stop+0x3b/0x440 [ 561.207981] kthread_stop+0x3b/0x440 [ 561.207995] cache_set_flush+0xd4/0x6d0 [bcache] [ 561.208008] process_one_work+0x856/0x1620 [ 561.208015] ? find_held_lock+0x39/0x1d0 [ 561.208028] ? drain_workqueue+0x380/0x380 [ 561.208048] worker_thread+0x87/0xb80 [ 561.208058] ? __kthread_parkme+0xb6/0x180 [ 561.208067] ? process_one_work+0x1620/0x1620 [ 561.208072] kthread+0x326/0x3e0 [ 561.208079] ? kthread_create_worker_on_cpu+0xc0/0xc0 [ 561.208090] ret_from_fork+0x3a/0x50 [ 561.208110] ================================================================== [ 561.208113] Disabling lock debugging due to kernel taint [ 561.208115] irq event stamp: 11800231 [ 561.208126] hardirqs last enabled at (11800231): [<ffffffff83008538>] do_syscall_64+0x18/0x410 [ 561.208127] BUG: unable to handle kernel NULL pointer dereference at 000000000000001c [ 561.208129] #PF error: [WRITE] [ 561.312253] hardirqs last disabled at (11800230): [<ffffffff830052ff>] trace_hardirqs_off_thunk+0x1a/0x1c [ 561.312259] softirqs last enabled at (11799832): [<ffffffff850005c7>] __do_softirq+0x5c7/0x8c3 [ 561.405975] PGD 0 P4D 0 [ 561.442494] softirqs last disabled at (11799821): [<ffffffff831add2c>] irq_exit+0x1ac/0x1e0 [ 561.791359] Oops: 0002 [#1] SMP KASAN NOPTI [ 561.791362] CPU: 15 PID: 313 Comm: kworker/15:1 Tainted: G B W 5.0.0-vanilla+ #3 [ 561.791363] Hardware name: Lenovo ThinkSystem SR650 -[7X05CTO1WW]-/-[7X05CTO1WW]-, BIOS -[IVE136T-2.10]- 03/22/2019 [ 561.791371] Workqueue: events cache_set_flush [bcache] [ 561.791374] RIP: 0010:kthread_stop+0x3b/0x440 [ 561.791376] Code: 00 00 65 8b 05 26 d5 e0 7c 89 c0 48 0f a3 05 ec aa df 02 0f 82 dc 02 00 00 4c 8d 63 20 be 04 00 00 00 4c 89 e7 e8 65 c5 53 00 <f0> ff 43 20 48 8d 7b 24 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 [ 561.791377] RSP: 0018:ffff88872fc8fd10 EFLAGS: 00010286 [ 561.838895] bcache: bch_count_io_errors() nvme0n1: IO error on writing btree. [ 561.838916] bcache: bch_count_io_errors() nvme0n1: IO error on writing btree. [ 561.838934] bcache: bch_count_io_errors() nvme0n1: IO error on writing btree. [ 561.838948] bcache: bch_count_io_errors() nvme0n1: IO error on writing btree. [ 561.838966] bcache: bch_count_io_errors() nvme0n1: IO error on writing btree. [ 561.838979] bcache: bch_count_io_errors() nvme0n1: IO error on writing btree. [ 561.838996] bcache: bch_count_io_errors() nvme0n1: IO error on writing btree. [ 563.067028] RAX: 0000000000000000 RBX: fffffffffffffffc RCX: ffffffff832dd314 [ 563.067030] RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000297 [ 563.067032] RBP: ffff88872fc8fe88 R08: fffffbfff0b8213d R09: fffffbfff0b8213d [ 563.067034] R10: 0000000000000001 R11: fffffbfff0b8213c R12: 000000000000001c [ 563.408618] R13: ffff88dc61cc0f68 R14: ffff888102b94900 R15: ffff88dc61cc0f68 [ 563.408620] FS: 0000000000000000(0000) GS:ffff888f7dc00000(0000) knlGS:0000000000000000 [ 563.408622] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 563.408623] CR2: 000000000000001c CR3: 0000000f48a1a004 CR4: 00000000007606e0 [ 563.408625] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 563.408627] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 563.904795] bcache: bch_count_io_errors() nvme0n1: IO error on writing btree. [ 563.915796] PKRU: 55555554 [ 563.915797] Call Trace: [ 563.915807] cache_set_flush+0xd4/0x6d0 [bcache] [ 563.915812] process_one_work+0x856/0x1620 [ 564.001226] bcache: bch_count_io_errors() nvme0n1: IO error on writing btree. [ 564.033563] ? find_held_lock+0x39/0x1d0 [ 564.033567] ? drain_workqueue+0x380/0x380 [ 564.033574] worker_thread+0x87/0xb80 [ 564.062823] bcache: bch_count_io_errors() nvme0n1: IO error on writing btree. [ 564.118042] ? __kthread_parkme+0xb6/0x180 [ 564.118046] ? process_one_work+0x1620/0x1620 [ 564.118048] kthread+0x326/0x3e0 [ 564.118050] ? kthread_create_worker_on_cpu+0xc0/0xc0 [ 564.167066] bcache: bch_count_io_errors() nvme0n1: IO error on writing btree. [ 564.252441] ret_from_fork+0x3a/0x50 [ 564.252447] Modules linked in: msr rpcrdma sunrpc rdma_ucm ib_iser ib_umad rdma_cm ib_ipoib i40iw configfs iw_cm ib_cm libiscsi scsi_transport_iscsi mlx4_ib ib_uverbs mlx4_en ib_core nls_iso8859_1 nls_cp437 vfat fat intel_rapl skx_edac x86_pkg_temp_thermal coretemp iTCO_wdt iTCO_vendor_support crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel ses raid0 aesni_intel cdc_ether enclosure usbnet ipmi_ssif joydev aes_x86_64 i40e scsi_transport_sas mii bcache md_mod crypto_simd mei_me ioatdma crc64 ptp cryptd pcspkr i2c_i801 mlx4_core glue_helper pps_core mei lpc_ich dca wmi ipmi_si ipmi_devintf nd_pmem dax_pmem nd_btt ipmi_msghandler device_dax pcc_cpufreq button hid_generic usbhid mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect xhci_pci sysimgblt fb_sys_fops xhci_hcd ttm megaraid_sas drm usbcore nfit libnvdimm sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua efivarfs [ 564.299390] bcache: bch_count_io_errors() nvme0n1: IO error on writing btree. [ 564.348360] CR2: 000000000000001c [ 564.348362] ---[ end trace b7f0e5cc7b2103b0 ]--- Therefore, it is not enough to only check whether c->gc_thread is NULL, we should use IS_ERR_OR_NULL() to check both NULL pointer and error value. This patch changes the above buggy code piece in this way, if (!IS_ERR_OR_NULL(c->gc_thread)) kthread_stop(c->gc_thread); Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bcache: acquire bch_register_lock later in cached_dev_free()Coly Li2019-07-261-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 80265d8dfd77792e133793cef44a21323aac2908 ] When enable lockdep engine, a lockdep warning can be observed when reboot or shutdown system, [ 3142.764557][ T1] bcache: bcache_reboot() Stopping all devices: [ 3142.776265][ T2649] [ 3142.777159][ T2649] ====================================================== [ 3142.780039][ T2649] WARNING: possible circular locking dependency detected [ 3142.782869][ T2649] 5.2.0-rc4-lp151.20-default+ #1 Tainted: G W [ 3142.785684][ T2649] ------------------------------------------------------ [ 3142.788479][ T2649] kworker/3:67/2649 is trying to acquire lock: [ 3142.790738][ T2649] 00000000aaf02291 ((wq_completion)bcache_writeback_wq){+.+.}, at: flush_workqueue+0x87/0x4c0 [ 3142.794678][ T2649] [ 3142.794678][ T2649] but task is already holding lock: [ 3142.797402][ T2649] 000000004fcf89c5 (&bch_register_lock){+.+.}, at: cached_dev_free+0x17/0x120 [bcache] [ 3142.801462][ T2649] [ 3142.801462][ T2649] which lock already depends on the new lock. [ 3142.801462][ T2649] [ 3142.805277][ T2649] [ 3142.805277][ T2649] the existing dependency chain (in reverse order) is: [ 3142.808902][ T2649] [ 3142.808902][ T2649] -> #2 (&bch_register_lock){+.+.}: [ 3142.812396][ T2649] __mutex_lock+0x7a/0x9d0 [ 3142.814184][ T2649] cached_dev_free+0x17/0x120 [bcache] [ 3142.816415][ T2649] process_one_work+0x2a4/0x640 [ 3142.818413][ T2649] worker_thread+0x39/0x3f0 [ 3142.820276][ T2649] kthread+0x125/0x140 [ 3142.822061][ T2649] ret_from_fork+0x3a/0x50 [ 3142.823965][ T2649] [ 3142.823965][ T2649] -> #1 ((work_completion)(&cl->work)#2){+.+.}: [ 3142.827244][ T2649] process_one_work+0x277/0x640 [ 3142.829160][ T2649] worker_thread+0x39/0x3f0 [ 3142.830958][ T2649] kthread+0x125/0x140 [ 3142.832674][ T2649] ret_from_fork+0x3a/0x50 [ 3142.834915][ T2649] [ 3142.834915][ T2649] -> #0 ((wq_completion)bcache_writeback_wq){+.+.}: [ 3142.838121][ T2649] lock_acquire+0xb4/0x1c0 [ 3142.840025][ T2649] flush_workqueue+0xae/0x4c0 [ 3142.842035][ T2649] drain_workqueue+0xa9/0x180 [ 3142.844042][ T2649] destroy_workqueue+0x17/0x250 [ 3142.846142][ T2649] cached_dev_free+0x52/0x120 [bcache] [ 3142.848530][ T2649] process_one_work+0x2a4/0x640 [ 3142.850663][ T2649] worker_thread+0x39/0x3f0 [ 3142.852464][ T2649] kthread+0x125/0x140 [ 3142.854106][ T2649] ret_from_fork+0x3a/0x50 [ 3142.855880][ T2649] [ 3142.855880][ T2649] other info that might help us debug this: [ 3142.855880][ T2649] [ 3142.859663][ T2649] Chain exists of: [ 3142.859663][ T2649] (wq_completion)bcache_writeback_wq --> (work_completion)(&cl->work)#2 --> &bch_register_lock [ 3142.859663][ T2649] [ 3142.865424][ T2649] Possible unsafe locking scenario: [ 3142.865424][ T2649] [ 3142.868022][ T2649] CPU0 CPU1 [ 3142.869885][ T2649] ---- ---- [ 3142.871751][ T2649] lock(&bch_register_lock); [ 3142.873379][ T2649] lock((work_completion)(&cl->work)#2); [ 3142.876399][ T2649] lock(&bch_register_lock); [ 3142.879727][ T2649] lock((wq_completion)bcache_writeback_wq); [ 3142.882064][ T2649] [ 3142.882064][ T2649] *** DEADLOCK *** [ 3142.882064][ T2649] [ 3142.885060][ T2649] 3 locks held by kworker/3:67/2649: [ 3142.887245][ T2649] #0: 00000000e774cdd0 ((wq_completion)events){+.+.}, at: process_one_work+0x21e/0x640 [ 3142.890815][ T2649] #1: 00000000f7df89da ((work_completion)(&cl->work)#2){+.+.}, at: process_one_work+0x21e/0x640 [ 3142.894884][ T2649] #2: 000000004fcf89c5 (&bch_register_lock){+.+.}, at: cached_dev_free+0x17/0x120 [bcache] [ 3142.898797][ T2649] [ 3142.898797][ T2649] stack backtrace: [ 3142.900961][ T2649] CPU: 3 PID: 2649 Comm: kworker/3:67 Tainted: G W 5.2.0-rc4-lp151.20-default+ #1 [ 3142.904789][ T2649] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018 [ 3142.909168][ T2649] Workqueue: events cached_dev_free [bcache] [ 3142.911422][ T2649] Call Trace: [ 3142.912656][ T2649] dump_stack+0x85/0xcb [ 3142.914181][ T2649] print_circular_bug+0x19a/0x1f0 [ 3142.916193][ T2649] __lock_acquire+0x16cd/0x1850 [ 3142.917936][ T2649] ? __lock_acquire+0x6a8/0x1850 [ 3142.919704][ T2649] ? lock_acquire+0xb4/0x1c0 [ 3142.921335][ T2649] ? find_held_lock+0x34/0xa0 [ 3142.923052][ T2649] lock_acquire+0xb4/0x1c0 [ 3142.924635][ T2649] ? flush_workqueue+0x87/0x4c0 [ 3142.926375][ T2649] flush_workqueue+0xae/0x4c0 [ 3142.928047][ T2649] ? flush_workqueue+0x87/0x4c0 [ 3142.929824][ T2649] ? drain_workqueue+0xa9/0x180 [ 3142.931686][ T2649] drain_workqueue+0xa9/0x180 [ 3142.933534][ T2649] destroy_workqueue+0x17/0x250 [ 3142.935787][ T2649] cached_dev_free+0x52/0x120 [bcache] [ 3142.937795][ T2649] process_one_work+0x2a4/0x640 [ 3142.939803][ T2649] worker_thread+0x39/0x3f0 [ 3142.941487][ T2649] ? process_one_work+0x640/0x640 [ 3142.943389][ T2649] kthread+0x125/0x140 [ 3142.944894][ T2649] ? kthread_create_worker_on_cpu+0x70/0x70 [ 3142.947744][ T2649] ret_from_fork+0x3a/0x50 [ 3142.970358][ T2649] bcache: bcache_device_free() bcache0 stopped Here is how the deadlock happens. 1) bcache_reboot() calls bcache_device_stop(), then inside bcache_device_stop() BCACHE_DEV_CLOSING bit is set on d->flags. Then closure_queue(&d->cl) is called to invoke cached_dev_flush(). 2) In cached_dev_flush(), cached_dev_free() is called by continu_at(). 3) In cached_dev_free(), when stopping the writeback kthread of the cached device by kthread_stop(), dc->writeback_thread will be waken up to quite the kthread while-loop, then cached_dev_put() is called in bch_writeback_thread(). 4) Calling cached_dev_put() in writeback kthread may drop dc->count to 0, then dc->detach kworker is scheduled, which is initialized as cached_dev_detach_finish(). 5) Inside cached_dev_detach_finish(), the last line of code is to call closure_put(&dc->disk.cl), which drops the last reference counter of closrure dc->disk.cl, then the callback cached_dev_flush() gets called. Now cached_dev_flush() is called for second time in the code path, the first time is in step 2). And again bch_register_lock will be acquired again, and a A-A lock (lockdep terminology) is happening. The root cause of the above A-A lock is in cached_dev_free(), mutex bch_register_lock is held before stopping writeback kthread and other kworkers. Fortunately now we have variable 'bcache_is_reboot', which may prevent device registration or unregistration during reboot/shutdown time, so it is unncessary to hold bch_register_lock such early now. This is how this patch fixes the reboot/shutdown time A-A lock issue: After moving mutex_lock(&bch_register_lock) to a later location where before atomic_read(&dc->running) in cached_dev_free(), such A-A lock problem can be solved without any reboot time registration race. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bcache: check CACHE_SET_IO_DISABLE bit in bch_journal()Coly Li2019-07-261-0/+4
| | | | | | | | | | | | | | | | | | | [ Upstream commit 383ff2183ad16a8842d1fbd9dd3e1cbd66813e64 ] When too many I/O errors happen on cache set and CACHE_SET_IO_DISABLE bit is set, bch_journal() may continue to work because the journaling bkey might be still in write set yet. The caller of bch_journal() may believe the journal still work but the truth is in-memory journal write set won't be written into cache device any more. This behavior may introduce potential inconsistent metadata status. This patch checks CACHE_SET_IO_DISABLE bit at the head of bch_journal(), if the bit is set, bch_journal() returns NULL immediately to notice caller to know journal does not work. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bcache: check CACHE_SET_IO_DISABLE in allocator codeColy Li2019-07-261-0/+9
| | | | | | | | | | | | | | | | | | | | [ Upstream commit e775339e1ae1205b47d94881db124c11385e597c ] If CACHE_SET_IO_DISABLE of a cache set flag is set by too many I/O errors, currently allocator routines can still continue allocate space which may introduce inconsistent metadata state. This patch checkes CACHE_SET_IO_DISABLE bit in following allocator routines, - bch_bucket_alloc() - __bch_bucket_alloc_set() Once CACHE_SET_IO_DISABLE is set on cache set, the allocator routines may reject allocation request earlier to avoid potential inconsistent metadata. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dm verity: use message limit for data block corruption messageMilan Broz2019-07-211-2/+2
| | | | | | | | | | | [ Upstream commit 2eba4e640b2c4161e31ae20090a53ee02a518657 ] DM verity should also use DMERR_LIMIT to limit repeat data block corruption messages. Signed-off-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dm table: don't copy from a NULL pointer in realloc_argv()Jerome Marchand2019-07-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit a0651926553cfe7992166432e418987760882652 ] For the first call to realloc_argv() in dm_split_args(), old_argv is NULL and size is zero. Then memcpy is called, with the NULL old_argv as the source argument and a zero size argument. AFAIK, this is undefined behavior and generates the following warning when compiled with UBSAN on ppc64le: In file included from ./arch/powerpc/include/asm/paca.h:19, from ./arch/powerpc/include/asm/current.h:16, from ./include/linux/sched.h:12, from ./include/linux/kthread.h:6, from drivers/md/dm-core.h:12, from drivers/md/dm-table.c:8: In function 'memcpy', inlined from 'realloc_argv' at drivers/md/dm-table.c:565:3, inlined from 'dm_split_args' at drivers/md/dm-table.c:588:9: ./include/linux/string.h:345:9: error: argument 2 null where non-null expected [-Werror=nonnull] return __builtin_memcpy(p, q, size); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/md/dm-table.c: In function 'dm_split_args': ./include/linux/string.h:345:9: note: in a call to built-in function '__builtin_memcpy' Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* md: fix for divide error in status_resyncMariusz Tkaczyk2019-07-141-14/+22
| | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 9642fa73d073527b0cbc337cc17a47d545d82cd2 ] Stopping external metadata arrays during resync/recovery causes retries, loop of interrupting and starting reconstruction, until it hit at good moment to stop completely. While these retries curr_mark_cnt can be small- especially on HDD drives, so subtraction result can be smaller than 0. However it is casted to uint without checking. As a result of it the status bar in /proc/mdstat while stopping is strange (it jumps between 0% and 99%). The real problem occurs here after commit 72deb455b5ec ("block: remove CONFIG_LBDAF"). Sector_div() macro has been changed, now the divisor is casted to uint32. For db = -8 the divisior(db/32-1) becomes 0. Check if db value can be really counted and replace these macro by div64_u64() inline. Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@intel.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* md/raid0: Do not bypass blocking queue entered for raid0 biosGuilherme G. Piccoli2019-07-101-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ----------------------------------------------------------------- This patch is not on mainline and is meant to 4.19 stable *only*. After the patch description there's a reasoning about that. ----------------------------------------------------------------- Commit cd4a4ae4683d ("block: don't use blocking queue entered for recursive bio submits") introduced the flag BIO_QUEUE_ENTERED in order split bios bypass the blocking queue entering routine and use the live non-blocking version. It was a result of an extensive discussion in a linux-block thread[0], and the purpose of this change was to prevent a hung task waiting on a reference to drop. Happens that md raid0 split bios all the time, and more important, it changes their underlying device to the raid member. After the change introduced by this flag's usage, we experience various crashes if a raid0 member is removed during a large write. This happens because the bio reaches the live queue entering function when the queue of the raid0 member is dying. A simple reproducer of this behavior is presented below: a) Build kernel v4.19.56-stable with CONFIG_BLK_DEV_THROTTLING=y. b) Create a raid0 md array with 2 NVMe devices as members, and mount it with an ext4 filesystem. c) Run the following oneliner (supposing the raid0 is mounted in /mnt): (dd of=/mnt/tmp if=/dev/zero bs=1M count=999 &); sleep 0.3; echo 1 > /sys/block/nvme1n1/device/device/remove (whereas nvme1n1 is the 2nd array member) This will trigger the following warning/oops: ------------[ cut here ]------------ BUG: unable to handle kernel NULL pointer dereference at 0000000000000155 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI RIP: 0010:blk_throtl_bio+0x45/0x970 [...] Call Trace: generic_make_request_checks+0x1bf/0x690 generic_make_request+0x64/0x3f0 raid0_make_request+0x184/0x620 [raid0] ? raid0_make_request+0x184/0x620 [raid0] md_handle_request+0x126/0x1a0 md_make_request+0x7b/0x180 generic_make_request+0x19e/0x3f0 submit_bio+0x73/0x140 [...] This patch changes raid0 driver to fallback to the "old" blocking queue entering procedure, by clearing the BIO_QUEUE_ENTERED from raid0 bios. This prevents the crashes and restores the regular behavior of raid0 arrays when a member is removed during a large write. [0] lore.kernel.org/linux-block/343bbbf6-64eb-879e-d19e-96aebb037d47@I-love.SAKURA.ne.jp ---------------------------- Why this is not on mainline? ---------------------------- The patch was originally submitted upstream in linux-raid and linux-block mailing-lists - it was initially accepted by Song Liu, but Christoph Hellwig[1] observed that there was a clean-up series ready to be accepted from Ming Lei[2] that fixed the same issue. The accepted patches from Ming's series in upstream are: commit 47cdee29ef9d ("block: move blk_exit_queue into __blk_release_queue") and commit fe2008640ae3 ("block: don't protect generic_make_request_checks with blk_queue_enter"). Those patches basically do a clean-up in the block layer involving: 1) Putting back blk_exit_queue() logic into __blk_release_queue(); that path was changed in the past and the logic from blk_exit_queue() was added to blk_cleanup_queue(). 2) Removing the guard/protection in generic_make_request_checks() with blk_queue_enter(). The problem with Ming's series for -stable is that it relies in the legacy request IO path removal. So it's "backport-able" to v5.0+, but doing that for early versions (like 4.19) would incur in complex code changes. Hence, it was suggested by Christoph and Song Liu that this patch was submitted to stable only; otherwise merging it upstream would add code to fix a path removed in a subsequent commit. [1] lore.kernel.org/linux-block/20190521172258.GA32702@infradead.org [2] lore.kernel.org/linux-block/20190515030310.20393-1-ming.lei@redhat.com Cc: Christoph Hellwig <hch@lst.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ming Lei <ming.lei@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Fixes: cd4a4ae4683d ("block: don't use blocking queue entered for recursive bio submits") Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm log writes: make sure super sector log updates are written in orderzhangyi (F)2019-07-031-2/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit 211ad4b733037f66f9be0a79eade3da7ab11cbb8 upstream. Currently, although we submit super bios in order (and super.nr_entries is incremented by each logged entry), submit_bio() is async so each super sector may not be written to log device in order and then the final nr_entries may be smaller than it should be. This problem can be reproduced by the xfstests generic/455 with ext4: QA output created by 455 -Silence is golden +mark 'end' does not exist Fix this by serializing submission of super sectors to make sure each is written to the log disk in order. Fixes: 0e9cebe724597 ("dm: add log writes target") Cc: stable@vger.kernel.org Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Suggested-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bcache: only set BCACHE_DEV_WB_RUNNING when cached device attachedColy Li2019-06-191-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1f0ffa67349c56ea54c03ccfd1e073c990e7411e upstream. When people set a writeback percent via sysfs file, /sys/block/bcache<N>/bcache/writeback_percent current code directly sets BCACHE_DEV_WB_RUNNING to dc->disk.flags and schedules kworker dc->writeback_rate_update. If there is no cache set attached to, the writeback kernel thread is not running indeed, running dc->writeback_rate_update does not make sense and may cause NULL pointer deference when reference cache set pointer inside update_writeback_rate(). This patch checks whether the cache set point (dc->disk.c) is NULL in sysfs interface handler, and only set BCACHE_DEV_WB_RUNNING and schedule dc->writeback_rate_update when dc->disk.c is not NULL (it means the cache device is attached to a cache set). This problem might be introduced from initial bcache commit, but commit 3fd47bfe55b0 ("bcache: stop dc->writeback_rate_update properly") changes part of the original code piece, so I add 'Fixes: 3fd47bfe55b0' to indicate from which commit this patch can be applied. Fixes: 3fd47bfe55b0 ("bcache: stop dc->writeback_rate_update properly") Reported-by: Bjørn Forsman <bjorn.forsman@gmail.com> Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Bjørn Forsman <bjorn.forsman@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bcache: fix stack corruption by PRECEDING_KEY()Coly Li2019-06-192-17/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 31b90956b124240aa8c63250243ae1a53585c5e2 upstream. Recently people report bcache code compiled with gcc9 is broken, one of the buggy behavior I observe is that two adjacent 4KB I/Os should merge into one but they don't. Finally it turns out to be a stack corruption caused by macro PRECEDING_KEY(). See how PRECEDING_KEY() is defined in bset.h, 437 #define PRECEDING_KEY(_k) \ 438 ({ \ 439 struct bkey *_ret = NULL; \ 440 \ 441 if (KEY_INODE(_k) || KEY_OFFSET(_k)) { \ 442 _ret = &KEY(KEY_INODE(_k), KEY_OFFSET(_k), 0); \ 443 \ 444 if (!_ret->low) \ 445 _ret->high--; \ 446 _ret->low--; \ 447 } \ 448 \ 449 _ret; \ 450 }) At line 442, _ret points to address of a on-stack variable combined by KEY(), the life range of this on-stack variable is in line 442-446, once _ret is returned to bch_btree_insert_key(), the returned address points to an invalid stack address and this address is overwritten in the following called bch_btree_iter_init(). Then argument 'search' of bch_btree_iter_init() points to some address inside stackframe of bch_btree_iter_init(), exact address depends on how the compiler allocates stack space. Now the stack is corrupted. Fixes: 0eacac22034c ("bcache: PRECEDING_KEY()") Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Rolf Fokkens <rolf@rolffokkens.nl> Reviewed-by: Pierre JUHEN <pierre.juhen@orange.fr> Tested-by: Shenghui Wang <shhuiw@foxmail.com> Tested-by: Pierre JUHEN <pierre.juhen@orange.fr> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Nix <nix@esperi.org.uk> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bcache: avoid clang -Wunintialized warningArnd Bergmann2019-05-311-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 78d4eb8ad9e1d413449d1b7a060f50b6efa81ebd ] clang has identified a code path in which it thinks a variable may be unused: drivers/md/bcache/alloc.c:333:4: error: variable 'bucket' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] fifo_pop(&ca->free_inc, bucket); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/md/bcache/util.h:219:27: note: expanded from macro 'fifo_pop' #define fifo_pop(fifo, i) fifo_pop_front(fifo, (i)) ^~~~~~~~~~~~~~~~~~~~~~~~~ drivers/md/bcache/util.h:189:6: note: expanded from macro 'fifo_pop_front' if (_r) { \ ^~ drivers/md/bcache/alloc.c:343:46: note: uninitialized use occurs here allocator_wait(ca, bch_allocator_push(ca, bucket)); ^~~~~~ drivers/md/bcache/alloc.c:287:7: note: expanded from macro 'allocator_wait' if (cond) \ ^~~~ drivers/md/bcache/alloc.c:333:4: note: remove the 'if' if its condition is always true fifo_pop(&ca->free_inc, bucket); ^ drivers/md/bcache/util.h:219:27: note: expanded from macro 'fifo_pop' #define fifo_pop(fifo, i) fifo_pop_front(fifo, (i)) ^ drivers/md/bcache/util.h:189:2: note: expanded from macro 'fifo_pop_front' if (_r) { \ ^ drivers/md/bcache/alloc.c:331:15: note: initialize the variable 'bucket' to silence this warning long bucket; ^ This cannot happen in practice because we only enter the loop if there is at least one element in the list. Slightly rearranging the code makes this clearer to both the reader and the compiler, which avoids the warning. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bcache: add failure check to run_cache_set() for journal replayColy Li2019-05-311-5/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit ce3e4cfb59cb382f8e5ce359238aa580d4ae7778 ] Currently run_cache_set() has no return value, if there is failure in bch_journal_replay(), the caller of run_cache_set() has no idea about such failure and just continue to execute following code after run_cache_set(). The internal failure is triggered inside bch_journal_replay() and being handled in async way. This behavior is inefficient, while failure handling inside bch_journal_replay(), cache register code is still running to start the cache set. Registering and unregistering code running as same time may introduce some rare race condition, and make the code to be more hard to be understood. This patch adds return value to run_cache_set(), and returns -EIO if bch_journal_rreplay() fails. Then caller of run_cache_set() may detect such failure and stop registering code flow immedidately inside register_cache_set(). If journal replay fails, run_cache_set() can report error immediately to register_cache_set(). This patch makes the failure handling for bch_journal_replay() be in synchronized way, easier to understand and debug, and avoid poetential race condition for register-and-unregister in same time. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bcache: fix failure in journal relplayTang Junhui2019-05-311-4/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 631207314d88e9091be02fbdd1fdadb1ae2ed79a ] journal replay failed with messages: Sep 10 19:10:43 ceph kernel: bcache: error on bb379a64-e44e-4812-b91d-a5599871a3b1: bcache: journal entries 2057493-2057567 missing! (replaying 2057493-2076601), disabling caching The reason is in journal_reclaim(), when discard is enabled, we send discard command and reclaim those journal buckets whose seq is old than the last_seq_now, but before we write a journal with last_seq_now, the machine is restarted, so the journal with the last_seq_now is not written to the journal bucket, and the last_seq_wrote in the newest journal is old than last_seq_now which we expect to be, so when we doing replay, journals from last_seq_wrote to last_seq_now are missing. It's hard to write a journal immediately after journal_reclaim(), and it harmless if those missed journal are caused by discarding since those journals are already wrote to btree node. So, if miss seqs are started from the beginning journal, we treat it as normal, and only print a message to show the miss journal, and point out it maybe caused by discarding. Patch v2 add a judgement condition to ignore the missed journal only when discard enabled as Coly suggested. (Coly Li: rebase the patch with other changes in bch_journal_replay()) Signed-off-by: Tang Junhui <tang.junhui.linux@gmail.com> Tested-by: Dennis Schridde <devurandom@gmx.net> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bcache: return error immediately in bch_journal_replay()Coly Li2019-05-311-3/+6
| | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 68d10e6979a3b59e3cd2e90bfcafed79c4cf180a ] When failure happens inside bch_journal_replay(), calling cache_set_err_on() and handling the failure in async way is not a good idea. Because after bch_journal_replay() returns, registering code will continue to execute following steps, and unregistering code triggered by cache_set_err_on() is running in same time. First it is unnecessary to handle failure and unregister cache set in an async way, second there might be potential race condition to run register and unregister code for same cache set. So in this patch, if failure happens in bch_journal_replay(), we don't call cache_set_err_on(), and just print out the same error message to kernel message buffer, then return -EIO immediately caller. Then caller can detect such failure and handle it in synchrnozied way. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bcache: avoid potential memleak of list of journal_replay(s) in the ↵Shenghui Wang2019-05-311-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | CACHE_SYNC branch of run_cache_set [ Upstream commit 95f18c9d1310730d075499a75aaf13bcd60405a7 ] In the CACHE_SYNC branch of run_cache_set(), LIST_HEAD(journal) is used to collect journal_replay(s) and filled by bch_journal_read(). If all goes well, bch_journal_replay() will release the list of jounal_replay(s) at the end of the branch. If something goes wrong, code flow will jump to the label "err:" and leave the list unreleased. This patch will release the list of journal_replay(s) in the case of error detected. v1 -> v2: * Move the release code to the location after label 'err:' to simply the change. Signed-off-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* md/raid: raid5 preserve the writeback action after the parity checkNigel Croxon2019-05-251-1/+9
| | | | | | | | | | | | | | | | | | commit b2176a1dfb518d870ee073445d27055fea64dfb8 upstream. The problem is that any 'uptodate' vs 'disks' check is not precise in this path. Put a "WARN_ON(!test_bit(R5_UPTODATE, &dev->flags)" on the device that might try to kick off writes and then skip the action. Better to prevent the raid driver from taking unexpected action *and* keep the system alive vs killing the machine with BUG_ON. Note: fixed warning reported by kbuild test robot <lkp@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Nigel Croxon <ncroxon@redhat.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "Don't jump to compute_result state from check_result state"Song Liu2019-05-251-4/+15
| | | | | | | | | | | | | commit a25d8c327bb41742dbd59f8c545f59f3b9c39983 upstream. This reverts commit 4f4fd7c5798bbdd5a03a60f6269cf1177fbd11ef. Cc: Dan Williams <dan.j.williams@intel.com> Cc: Nigel Croxon <ncroxon@redhat.com> Cc: Xiao Ni <xni@redhat.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm mpath: always free attached_handler_name in parse_path()Martin Wilck2019-05-251-1/+1
| | | | | | | | | | | | | | | | | | | | commit 940bc471780b004a5277c1931f52af363c2fc9da upstream. Commit b592211c33f7 ("dm mpath: fix attached_handler_name leak and dangling hw_handler_name pointer") fixed a memory leak for the case where setup_scsi_dh() returns failure. But setup_scsi_dh may return success and not "use" attached_handler_name if the retain_attached_hwhandler flag is not set on the map. As setup_scsi_sh properly "steals" the pointer by nullifying it, freeing it unconditionally in parse_path() is safe. Fixes: b592211c33f7 ("dm mpath: fix attached_handler_name leak and dangling hw_handler_name pointer") Cc: stable@vger.kernel.org Reported-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Martin Wilck <mwilck@suse.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm integrity: correctly calculate the size of metadata areaMikulas Patocka2019-05-251-2/+2
| | | | | | | | | | | | | | | | | | | | commit 30bba430ddf737978e40561198693ba91386dac1 upstream. When we use separate devices for data and metadata, dm-integrity would incorrectly calculate the size of the metadata device as if it had 512-byte block size - and it would refuse activation with larger block size and smaller metadata device. Fix this so that it takes actual block size into account, which fixes the following reported issue: https://gitlab.com/cryptsetup/cryptsetup/issues/450 Fixes: 356d9d52e122 ("dm integrity: allow separate metadata device") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm delay: fix a crash when invalid device is specifiedMikulas Patocka2019-05-251-1/+2
| | | | | | | | | | | | | | commit 81bc6d150ace6250503b825d9d0c10f7bbd24095 upstream. When the target line contains an invalid device, delay_ctr() will call delay_dtr() with NULL workqueue. Attempting to destroy the NULL workqueue causes a crash. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm zoned: Fix zone report handlingDamien Le Moal2019-05-251-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7aedf75ff740a98f3683439449cd91c8662d03b2 upstream. The function blkdev_report_zones() returns success even if no zone information is reported (empty report). Empty zone reports can only happen if the report start sector passed exceeds the device capacity. The conditions for this to happen are either a bug in the caller code, or, a change in the device that forced the low level driver to change the device capacity to a value that is lower than the report start sector. This situation includes a failed disk revalidation resulting in the disk capacity being changed to 0. If this change happens while dm-zoned is in its initialization phase executing dmz_init_zones(), this function may enter an infinite loop and hang the system. To avoid this, add a check to disallow empty zone reports and bail out early. Also fix the function dmz_update_zone() to make sure that the report for the requested zone was correctly obtained. Fixes: 3b1a94c88b79 ("dm zoned: drive-managed zoned block device target") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Shaun Tancheff <shaun@tancheff.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm cache metadata: Fix loading discard bitsetNikos Tsironis2019-05-251-1/+8
| | | | | | | | | | | | | | | | | commit e28adc3bf34e434b30e8d063df4823ba0f3e0529 upstream. Add missing dm_bitset_cursor_next() to properly advance the bitset cursor. Otherwise, the discarded state of all blocks is set according to the discarded state of the first block. Fixes: ae4a46a1f6 ("dm cache metadata: use bitset cursor api to load discard bitset") Cc: stable@vger.kernel.org Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* md: add mddev->pers to avoid potential NULL pointer dereferenceYufen Yu2019-05-251-2/+4
| | | | | | | | | | | | | | | | | | commit ee37e62191a59d253fc916b9fc763deb777211e2 upstream. When doing re-add, we need to ensure rdev->mddev->pers is not NULL, which can avoid potential NULL pointer derefence in fallowing add_bound_rdev(). Fixes: a6da4ef85cef ("md: re-add a failed disk") Cc: Xiao Ni <xni@redhat.com> Cc: NeilBrown <neilb@suse.com> Cc: <stable@vger.kernel.org> # 4.4+ Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* md: batch flush requests.NeilBrown2019-05-252-4/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 2bc13b83e6298486371761de503faeffd15b7534 upstream. Currently if many flush requests are submitted to an md device is quick succession, they are serialized and can take a long to process them all. We don't really need to call flush all those times - a single flush call can satisfy all requests submitted before it started. So keep track of when the current flush started and when it finished, allow any pending flush that was requested before the flush started to complete without waiting any more. Test results from Xiao: Test is done on a raid10 device which is created by 4 SSDs. The tool is dbench. 1. The latest linux stable kernel Operation Count AvgLat MaxLat -------------------------------------------------- Deltree 768 10.509 78.305 Flush 2078376 0.013 10.094 Close 21787697 0.019 18.821 LockX 96580 0.007 3.184 Mkdir 384 0.008 0.062 Rename 1255883 0.191 23.534 ReadX 46495589 0.020 14.230 WriteX 14790591 7.123 60.706 Unlink 5989118 0.440 54.551 UnlockX 96580 0.005 2.736 FIND_FIRST 10393845 0.042 12.079 SET_FILE_INFORMATION 2415558 0.129 10.088 QUERY_FILE_INFORMATION 4711725 0.005 8.462 QUERY_PATH_INFORMATION 26883327 0.032 21.715 QUERY_FS_INFORMATION 4929409 0.010 8.238 NTCreateX 29660080 0.100 53.268 Throughput 1034.88 MB/sec (sync open) 128 clients 128 procs max_latency=60.712 ms 2. With patch1 "Revert "MD: fix lock contention for flush bios"" Operation Count AvgLat MaxLat -------------------------------------------------- Deltree 256 8.326 36.761 Flush 693291 3.974 180.269 Close 7266404 0.009 36.929 LockX 32160 0.006 0.840 Mkdir 128 0.008 0.021 Rename 418755 0.063 29.945 ReadX 15498708 0.007 7.216 WriteX 4932310 22.482 267.928 Unlink 1997557 0.109 47.553 UnlockX 32160 0.004 1.110 FIND_FIRST 3465791 0.036 7.320 SET_FILE_INFORMATION 805825 0.015 1.561 QUERY_FILE_INFORMATION 1570950 0.005 2.403 QUERY_PATH_INFORMATION 8965483 0.013 14.277 QUERY_FS_INFORMATION 1643626 0.009 3.314 NTCreateX 9892174 0.061 41.278 Throughput 345.009 MB/sec (sync open) 128 clients 128 procs max_latency=267.939 m 3. With patch1 and patch2 Operation Count AvgLat MaxLat -------------------------------------------------- Deltree 768 9.570 54.588 Flush 2061354 0.666 15.102 Close 21604811 0.012 25.697 LockX 95770 0.007 1.424 Mkdir 384 0.008 0.053 Rename 1245411 0.096 12.263 ReadX 46103198 0.011 12.116 WriteX 14667988 7.375 60.069 Unlink 5938936 0.173 30.905 UnlockX 95770 0.005 4.147 FIND_FIRST 10306407 0.041 11.715 SET_FILE_INFORMATION 2395987 0.048 7.640 QUERY_FILE_INFORMATION 4672371 0.005 9.291 QUERY_PATH_INFORMATION 26656735 0.018 19.719 QUERY_FS_INFORMATION 4887940 0.010 7.654 NTCreateX 29410811 0.059 28.551 Throughput 1026.21 MB/sec (sync open) 128 clients 128 procs max_latency=60.075 ms Cc: <stable@vger.kernel.org> # v4.19+ Tested-by: Xiao Ni <xni@redhat.com> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "MD: fix lock contention for flush bios"NeilBrown2019-05-252-123/+62Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 4bc034d35377196c854236133b07730a777c4aba upstream. This reverts commit 5a409b4f56d50b212334f338cb8465d65550cd85. This patch has two problems. 1/ it make multiple calls to submit_bio() from inside a make_request_fn. The bios thus submitted will be queued on current->bio_list and not submitted immediately. As the bios are allocated from a mempool, this can theoretically result in a deadlock - all the pool of requests could be in various ->bio_list queues and a subsequent mempool_alloc could block waiting for one of them to be released. 2/ It aims to handle a case when there are many concurrent flush requests. It handles this by submitting many requests in parallel - all of which are identical and so most of which do nothing useful. It would be more efficient to just send one lower-level request, but allow that to satisfy multiple upper-level requests. Fixes: 5a409b4f56d5 ("MD: fix lock contention for flush bios") Cc: <stable@vger.kernel.org> # v4.19+ Tested-by: Xiao Ni <xni@redhat.com> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bcache: never set KEY_PTRS of journal key to 0 in journal_reclaim()Coly Li2019-05-221-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1bee2addc0c8470c8aaa65ef0599eeae96dd88bc upstream. In journal_reclaim() ja->cur_idx of each cache will be update to reclaim available journal buckets. Variable 'int n' is used to count how many cache is successfully reclaimed, then n is set to c->journal.key by SET_KEY_PTRS(). Later in journal_write_unlocked(), a for_each_cache() loop will write the jset data onto each cache. The problem is, if all jouranl buckets on each cache is full, the following code in journal_reclaim(), 529 for_each_cache(ca, c, iter) { 530 struct journal_device *ja = &ca->journal; 531 unsigned int next = (ja->cur_idx + 1) % ca->sb.njournal_buckets; 532 533 /* No space available on this device */ 534 if (next == ja->discard_idx) 535 continue; 536 537 ja->cur_idx = next; 538 k->ptr[n++] = MAKE_PTR(0, 539 bucket_to_sector(c, ca->sb.d[ja->cur_idx]), 540 ca->sb.nr_this_dev); 541 } 542 543 bkey_init(k); 544 SET_KEY_PTRS(k, n); If there is no available bucket to reclaim, the if() condition at line 534 will always true, and n remains 0. Then at line 544, SET_KEY_PTRS() will set KEY_PTRS field of c->journal.key to 0. Setting KEY_PTRS field of c->journal.key to 0 is wrong. Because in journal_write_unlocked() the journal data is written in following loop, 649 for (i = 0; i < KEY_PTRS(k); i++) { 650-671 submit journal data to cache device 672 } If KEY_PTRS field is set to 0 in jouranl_reclaim(), the journal data won't be written to cache device here. If system crahed or rebooted before bkeys of the lost journal entries written into btree nodes, data corruption will be reported during bcache reload after rebooting the system. Indeed there is only one cache in a cache set, there is no need to set KEY_PTRS field in journal_reclaim() at all. But in order to keep the for_each_cache() logic consistent for now, this patch fixes the above problem by not setting 0 KEY_PTRS of journal key, if there is no bucket available to reclaim. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bcache: fix a race between cache register and cacheset unregisterLiang Chen2019-05-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit a4b732a248d12cbdb46999daf0bf288c011335eb upstream. There is a race between cache device register and cache set unregister. For an already registered cache device, register_bcache will call bch_is_open to iterate through all cachesets and check every cache there. The race occurs if cache_set_free executes at the same time and clears the caches right before ca is dereferenced in bch_is_open_cache. To close the race, let's make sure the clean up work is protected by the bch_register_lock as well. This issue can be reproduced as follows, while true; do echo /dev/XXX> /sys/fs/bcache/register ; done& while true; do echo 1> /sys/block/XXX/bcache/set/unregister ; done & and results in the following oops, [ +0.000053] BUG: unable to handle kernel NULL pointer dereference at 0000000000000998 [ +0.000457] #PF error: [normal kernel read fault] [ +0.000464] PGD 800000003ca9d067 P4D 800000003ca9d067 PUD 3ca9c067 PMD 0 [ +0.000388] Oops: 0000 [#1] SMP PTI [ +0.000269] CPU: 1 PID: 3266 Comm: bash Not tainted 5.0.0+ #6 [ +0.000346] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.fc28 04/01/2014 [ +0.000472] RIP: 0010:register_bcache+0x1829/0x1990 [bcache] [ +0.000344] Code: b0 48 83 e8 50 48 81 fa e0 e1 10 c0 0f 84 a9 00 00 00 48 89 c6 48 89 ca 0f b7 ba 54 04 00 00 4c 8b 82 60 0c 00 00 85 ff 74 2f <49> 3b a8 98 09 00 00 74 4e 44 8d 47 ff 31 ff 49 c1 e0 03 eb 0d [ +0.000839] RSP: 0018:ffff92ee804cbd88 EFLAGS: 00010202 [ +0.000328] RAX: ffffffffc010e190 RBX: ffff918b5c6b5000 RCX: ffff918b7d8e0000 [ +0.000399] RDX: ffff918b7d8e0000 RSI: ffffffffc010e190 RDI: 0000000000000001 [ +0.000398] RBP: ffff918b7d318340 R08: 0000000000000000 R09: ffffffffb9bd2d7a [ +0.000385] R10: ffff918b7eb253c0 R11: ffffb95980f51200 R12: ffffffffc010e1a0 [ +0.000411] R13: fffffffffffffff2 R14: 000000000000000b R15: ffff918b7e232620 [ +0.000384] FS: 00007f955bec2740(0000) GS:ffff918b7eb00000(0000) knlGS:0000000000000000 [ +0.000420] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ +0.000801] CR2: 0000000000000998 CR3: 000000003cad6000 CR4: 00000000001406e0 [ +0.000837] Call Trace: [ +0.000682] ? _cond_resched+0x10/0x20 [ +0.000691] ? __kmalloc+0x131/0x1b0 [ +0.000710] kernfs_fop_write+0xfa/0x170 [ +0.000733] __vfs_write+0x2e/0x190 [ +0.000688] ? inode_security+0x10/0x30 [ +0.000698] ? selinux_file_permission+0xd2/0x120 [ +0.000752] ? security_file_permission+0x2b/0x100 [ +0.000753] vfs_write+0xa8/0x1a0 [ +0.000676] ksys_write+0x4d/0xb0 [ +0.000699] do_syscall_64+0x3a/0xf0 [ +0.000692] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Liang Chen <liangchen.linux@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Don't jump to compute_result state from check_result stateNigel Croxon2019-05-161-15/+4Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 4f4fd7c5798bbdd5a03a60f6269cf1177fbd11ef upstream. Changing state from check_state_check_result to check_state_compute_result not only is unsafe but also doesn't appear to serve a valid purpose. A raid6 check should only be pushing out extra writes if doing repair and a mis-match occurs. The stripe dev management will already try and do repair writes for failing sectors. This patch makes the raid6 check_state_check_result handling work more like raid5's. If somehow too many failures for a check, just quit the check operation for the stripe. When any checks pass, don't try and use check_state_compute_result for a purpose it isn't needed for and is unsafe for. Just mark the stripe as in sync for passing its parity checks and let the stripe dev read/write code and the bad blocks list do their job handling I/O errors. Repro steps from Xiao: These are the steps to reproduce this problem: 1. redefined OPT_MEDIUM_ERR_ADDR to 12000 in scsi_debug.c 2. insmod scsi_debug.ko dev_size_mb=11000 max_luns=1 num_tgts=1 3. mdadm --create /dev/md127 --level=6 --raid-devices=5 /dev/sde1 /dev/sde2 /dev/sde3 /dev/sde5 /dev/sde6 sde is the disk created by scsi_debug 4. echo "2" >/sys/module/scsi_debug/parameters/opts 5. raid-check It panic: [ 4854.730899] md: data-check of RAID array md127 [ 4854.857455] sd 5:0:0:0: [sdr] tag#80 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [ 4854.859246] sd 5:0:0:0: [sdr] tag#80 Sense Key : Medium Error [current] [ 4854.860694] sd 5:0:0:0: [sdr] tag#80 Add. Sense: Unrecovered read error [ 4854.862207] sd 5:0:0:0: [sdr] tag#80 CDB: Read(10) 28 00 00 00 2d 88 00 04 00 00 [ 4854.864196] print_req_error: critical medium error, dev sdr, sector 11656 flags 0 [ 4854.867409] sd 5:0:0:0: [sdr] tag#100 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [ 4854.869469] sd 5:0:0:0: [sdr] tag#100 Sense Key : Medium Error [current] [ 4854.871206] sd 5:0:0:0: [sdr] tag#100 Add. Sense: Unrecovered read error [ 4854.872858] sd 5:0:0:0: [sdr] tag#100 CDB: Read(10) 28 00 00 00 2e e0 00 00 08 00 [ 4854.874587] print_req_error: critical medium error, dev sdr, sector 12000 flags 4000 [ 4854.876456] sd 5:0:0:0: [sdr] tag#101 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [ 4854.878552] sd 5:0:0:0: [sdr] tag#101 Sense Key : Medium Error [current] [ 4854.880278] sd 5:0:0:0: [sdr] tag#101 Add. Sense: Unrecovered read error [ 4854.881846] sd 5:0:0:0: [sdr] tag#101 CDB: Read(10) 28 00 00 00 2e e8 00 00 08 00 [ 4854.883691] print_req_error: critical medium error, dev sdr, sector 12008 flags 4000 [ 4854.893927] sd 5:0:0:0: [sdr] tag#166 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [ 4854.896002] sd 5:0:0:0: [sdr] tag#166 Sense Key : Medium Error [current] [ 4854.897561] sd 5:0:0:0: [sdr] tag#166 Add. Sense: Unrecovered read error [ 4854.899110] sd 5:0:0:0: [sdr] tag#166 CDB: Read(10) 28 00 00 00 2e e0 00 00 10 00 [ 4854.900989] print_req_error: critical medium error, dev sdr, sector 12000 flags 0 [ 4854.902757] md/raid:md127: read error NOT corrected!! (sector 9952 on sdr1). [ 4854.904375] md/raid:md127: read error NOT corrected!! (sector 9960 on sdr1). [ 4854.906201] ------------[ cut here ]------------ [ 4854.907341] kernel BUG at drivers/md/raid5.c:4190! raid5.c:4190 above is this BUG_ON: handle_parity_checks6() ... BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */ Cc: <stable@vger.kernel.org> # v3.16+ OriginalAuthor: David Jeffery <djeffery@redhat.com> Cc: Xiao Ni <xni@redhat.com> Tested-by: David Jeffery <djeffery@redhat.com> Signed-off-by: David Jeffy <djeffery@redhat.com> Signed-off-by: Nigel Croxon <ncroxon@redhat.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm integrity: fix deadlock with overlapping I/OMikulas Patocka2019-04-171-3/+1Star
| | | | | | | | | | | | | | | | | | | | | commit 4ed319c6ac08e9a28fca7ac188181ac122f4de84 upstream. dm-integrity will deadlock if overlapping I/O is issued to it, the bug was introduced by commit 724376a04d1a ("dm integrity: implement fair range locks"). Users rarely use overlapping I/O so this bug went undetected until now. Fix this bug by correcting, likely cut-n-paste, typos in ranges_overlap() and also remove a flawed ranges_overlap() check in remove_range_unlocked(). This condition could leave unprocessed bios hanging on wait_list forever. Cc: stable@vger.kernel.org # v4.19+ Fixes: 724376a04d1a ("dm integrity: implement fair range locks") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm table: propagate BDI_CAP_STABLE_WRITES to fix sporadic checksum errorsIlya Dryomov2019-04-171-0/+39
| | | | | | | | | | | | | | | | | commit eb40c0acdc342b815d4d03ae6abb09e80c0f2988 upstream. Some devices don't use blk_integrity but still want stable pages because they do their own checksumming. Examples include rbd and iSCSI when data digests are negotiated. Stacking DM (and thus LVM) on top of these devices results in sporadic checksum errors. Set BDI_CAP_STABLE_WRITES if any underlying device has it set. Cc: stable@vger.kernel.org Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm: revert 8f50e358153d ("dm: limit the max bio size as BIO_MAX_PAGES * ↵Mikulas Patocka2019-04-171-9/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | PAGE_SIZE") commit 75ae193626de3238ca5fb895868ec91c94e63b1b upstream. The limit was already incorporated to dm-crypt with commit 4e870e948fba ("dm crypt: fix error with too large bios"), so we don't need to apply it globally to all targets. The quantity BIO_MAX_PAGES * PAGE_SIZE is wrong anyway because the variable ti->max_io_len it is supposed to be in the units of 512-byte sectors not in bytes. Reduction of the limit to 1048576 sectors could even cause data corruption in rare cases - suppose that we have a dm-striped device with stripe size 768MiB. The target will call dm_set_target_max_io_len with the value 1572864. The buggy code would reduce it to 1048576. Now, the dm-core will errorneously split the bios on 1048576-sector boundary insetad of 1572864-sector boundary and pass these stripe-crossing bios to the striped target. Cc: stable@vger.kernel.org # v4.16+ Fixes: 8f50e358153d ("dm: limit the max bio size as BIO_MAX_PAGES * PAGE_SIZE") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dm integrity: change memcmp to strncmp in dm_integrity_ctrMikulas Patocka2019-04-171-4/+4
| | | | | | | | | | | | | | | | | commit 0d74e6a3b6421d98eeafbed26f29156d469bc0b5 upstream. If the string opt_string is small, the function memcmp can access bytes that are beyond the terminating nul character. In theory, it could cause segfault, if opt_string were located just below some unmapped memory. Change from memcmp to strncmp so that we don't read bytes beyond the end of the string. Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bcache: fix potential div-zero error of writeback_rate_p_term_inverseColy Li2019-04-051-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 5b5fd3c94eef69dcfaa8648198e54c92e5687d6d ] Current code already uses d_strtoul_nonzero() to convert input string to an unsigned integer, to make sure writeback_rate_p_term_inverse won't be zero value. But overflow may happen when converting input string to an unsigned integer value by d_strtoul_nonzero(), then dc->writeback_rate_p_term_inverse can still be set to 0 even if the sysfs file input value is not zero, e.g. 4294967296 (a.k.a UINT_MAX+1). If dc->writeback_rate_p_term_inverse is set to 0, it might cause a dev-zero error in following code from __update_writeback_rate(), int64_t proportional_scaled = div_s64(error, dc->writeback_rate_p_term_inverse); This patch replaces d_strtoul_nonzero() by sysfs_strtoul_clamp() and limit the value range in [1, UINT_MAX]. Then the unsigned integer overflow and dev-zero error can be avoided. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bcache: improve sysfs_strtoul_clamp()Coly Li2019-04-051-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 596b5a5dd1bc2fa019fdaaae522ef331deef927f ] Currently sysfs_strtoul_clamp() is defined as, 82 #define sysfs_strtoul_clamp(file, var, min, max) \ 83 do { \ 84 if (attr == &sysfs_ ## file) \ 85 return strtoul_safe_clamp(buf, var, min, max) \ 86 ?: (ssize_t) size; \ 87 } while (0) The problem is, if bit width of var is less then unsigned long, min and max may not protect var from integer overflow, because overflow happens in strtoul_safe_clamp() before checking min and max. To fix such overflow in sysfs_strtoul_clamp(), to make min and max take effect, this patch adds an unsigned long variable, and uses it to macro strtoul_safe_clamp() to convert an unsigned long value in range defined by [min, max]. Then assign this value to var. By this method, if bit width of var is less than unsigned long, integer overflow won't happen before min and max are checking. Now sysfs_strtoul_clamp() can properly handle smaller data type like unsigned int, of cause min and max should be defined in range of unsigned int too. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bcache: fix potential div-zero error of writeback_rate_i_term_inverseColy Li2019-04-051-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit c3b75a2199cdbfc1c335155fe143d842604b1baa ] dc->writeback_rate_i_term_inverse can be set via sysfs interface. It is in type unsigned int, and convert from input string by d_strtoul(). The problem is d_strtoul() does not check valid range of the input, if 4294967296 is written into sysfs file writeback_rate_i_term_inverse, an overflow of unsigned integer will happen and value 0 is set to dc->writeback_rate_i_term_inverse. In writeback.c:__update_writeback_rate(), there are following lines of code, integral_scaled = div_s64(dc->writeback_rate_integral, dc->writeback_rate_i_term_inverse); If dc->writeback_rate_i_term_inverse is set to 0 via sysfs interface, a div-zero error might be triggered in the above code. Therefore we need to add a range limitation in the sysfs interface, this is what this patch does, use sysfs_stroul_clamp() to replace d_strtoul() and restrict the input range in [1, UINT_MAX]. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bcache: fix input overflow to sequential_cutoffColy Li2019-04-051-1/+3
| | | | | | | | | | | | | | | | | | [ Upstream commit 8c27a3953e92eb0b22dbb03d599f543a05f9574e ] People may set sequential_cutoff of a cached device via sysfs file, but current code does not check input value overflow. E.g. if value 4294967295 (UINT_MAX) is written to file sequential_cutoff, its value is 4GB, but if 4294967296 (UINT_MAX + 1) is written into, its value will be 0. This is an unexpected behavior. This patch replaces d_strtoi_h() by sysfs_strtoul_clamp() to convert input string to unsigned integer value, and limit its range in [0, UINT_MAX]. Then the input overflow can be fixed. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bcache: fix input overflow to cache set sysfs file io_error_halflifeColy Li2019-04-051-2/+11
| | | | | | | | | | | | | | | | | [ Upstream commit a91fbda49f746119828f7e8ad0f0aa2ab0578f65 ] Cache set sysfs entry io_error_halflife is used to set c->error_decay. c->error_decay is in type unsigned int, and it is converted by strtoul_or_return(), therefore overflow to c->error_decay is possible for a large input value. This patch fixes the overflow by using strtoul_safe_clamp() to convert input string to an unsigned long value in range [0, UINT_MAX], then divides by 88 and set it to c->error_decay. Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dm thin: add sanity checks to thin-pool and external snapshot creationJason Cai (Xiang Feng)2019-04-051-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 70de2cbda8a5d788284469e755f8b097d339c240 ] Invoking dm_get_device() twice on the same device path with different modes is dangerous. Because in that case, upgrade_mode() will alloc a new 'dm_dev' and free the old one, which may be referenced by a previous caller. Dereferencing the dangling pointer will trigger kernel NULL pointer dereference. The following two cases can reproduce this issue. Actually, they are invalid setups that must be disallowed, e.g.: 1. Creating a thin-pool with read_only mode, and the same device as both metadata and data. dmsetup create thinp --table \ "0 41943040 thin-pool /dev/vdb /dev/vdb 128 0 1 read_only" BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 ... Call Trace: new_read+0xfb/0x110 [dm_bufio] dm_bm_read_lock+0x43/0x190 [dm_persistent_data] ? kmem_cache_alloc_trace+0x15c/0x1e0 __create_persistent_data_objects+0x65/0x3e0 [dm_thin_pool] dm_pool_metadata_open+0x8c/0xf0 [dm_thin_pool] pool_ctr.cold.79+0x213/0x913 [dm_thin_pool] ? realloc_argv+0x50/0x70 [dm_mod] dm_table_add_target+0x14e/0x330 [dm_mod] table_load+0x122/0x2e0 [dm_mod] ? dev_status+0x40/0x40 [dm_mod] ctl_ioctl+0x1aa/0x3e0 [dm_mod] dm_ctl_ioctl+0xa/0x10 [dm_mod] do_vfs_ioctl+0xa2/0x600 ? handle_mm_fault+0xda/0x200 ? __do_page_fault+0x26c/0x4f0 ksys_ioctl+0x60/0x90 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x55/0x150 entry_SYSCALL_64_after_hwframe+0x44/0xa9 2. Creating a external snapshot using the same thin-pool device. dmsetup create thinp --table \ "0 41943040 thin-pool /dev/vdc /dev/vdb 128 0 2 ignore_discard" dmsetup message /dev/mapper/thinp 0 "create_thin 0" dmsetup create snap --table \ "0 204800 thin /dev/mapper/thinp 0 /dev/mapper/thinp" BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 ... Call Trace: ? __alloc_pages_nodemask+0x13c/0x2e0 retrieve_status+0xa5/0x1f0 [dm_mod] ? dm_get_live_or_inactive_table.isra.7+0x20/0x20 [dm_mod] table_status+0x61/0xa0 [dm_mod] ctl_ioctl+0x1aa/0x3e0 [dm_mod] dm_ctl_ioctl+0xa/0x10 [dm_mod] do_vfs_ioctl+0xa2/0x600 ksys_ioctl+0x60/0x90 ? ksys_write+0x4f/0xb0 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x55/0x150 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Jason Cai (Xiang Feng) <jason.cai@linux.alibaba.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bcache: use (REQ_META|REQ_PRIO) to indicate bio for metadataColy Li2019-03-231-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit dc7292a5bcb4c878b076fca2ac3fc22f81b8f8df upstream. In 'commit 752f66a75aba ("bcache: use REQ_PRIO to indicate bio for metadata")' REQ_META is replaced by REQ_PRIO to indicate metadata bio. This assumption is not always correct, e.g. XFS uses REQ_META to mark metadata bio other than REQ_PRIO. This is why Nix noticed that bcache does not cache metadata for XFS after the above commit. Thanks to Dave Chinner, he explains the difference between REQ_META and REQ_PRIO from view of file system developer. Here I quote part of his explanation from mailing list, REQ_META is used for metadata. REQ_PRIO is used to communicate to the lower layers that the submitter considers this IO to be more important that non REQ_PRIO IO and so dispatch should be expedited. IOWs, if the filesystem considers metadata IO to be more important that user data IO, then it will use REQ_PRIO | REQ_META rather than just REQ_META. Then it seems bios with REQ_META or REQ_PRIO should both be cached for performance optimation, because they are all probably low I/O latency demand by upper layer (e.g. file system). So in this patch, when we want to decide whether to bypass the cache, REQ_META and REQ_PRIO are both checked. Then both metadata and high priority I/O requests will be handled properly. Reported-by: Nix <nix@esperi.org.uk> Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Andre Noll <maan@tuebingen.mpg.de> Tested-by: Nix <nix@esperi.org.uk> Cc: stable@vger.kernel.org Cc: Dave Chinner <david@fromorbit.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>