user/sven/linux.git/drivers/md, branch v4.4.243

md/raid5: fix oops during stripe resizing

2020-11-10T09:22:15Z

commit b44c018cdf748b96b676ba09fdbc5b34fc443ada upstream. KoWei reported crash during raid5 reshape: [ 1032.252932] Oops: 0002 [#1] SMP PTI [...] [ 1032.252943] RIP: 0010:memcpy_erms+0x6/0x10 [...] [ 1032.252947] RSP: 0018:ffffba1ac0c03b78 EFLAGS: 00010286 [ 1032.252949] RAX: 0000784ac0000000 RBX: ffff91bec3d09740 RCX: 0000000000001000 [ 1032.252951] RDX: 0000000000001000 RSI: ffff91be6781c000 RDI: 0000784ac0000000 [ 1032.252953] RBP: ffffba1ac0c03bd8 R08: 0000000000001000 R09: ffffba1ac0c03bf8 [ 1032.252954] R10: 0000000000000000 R11: 0000000000000000 R12: ffffba1ac0c03bf8 [ 1032.252955] R13: 0000000000001000 R14: 0000000000000000 R15: 0000000000000000 [ 1032.252958] FS: 0000000000000000(0000) GS:ffff91becf500000(0000) knlGS:0000000000000000 [ 1032.252959] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1032.252961] CR2: 0000784ac0000000 CR3: 000000031780a002 CR4: 00000000001606e0 [ 1032.252962] Call Trace: [ 1032.252969] ? async_memcpy+0x179/0x1000 [async_memcpy] [ 1032.252977] ? raid5_release_stripe+0x8e/0x110 [raid456] [ 1032.252982] handle_stripe_expansion+0x15a/0x1f0 [raid456] [ 1032.252988] handle_stripe+0x592/0x1270 [raid456] [ 1032.252993] handle_active_stripes.isra.0+0x3cb/0x5a0 [raid456] [ 1032.252999] raid5d+0x35c/0x550 [raid456] [ 1032.253002] ? schedule+0x42/0xb0 [ 1032.253006] ? schedule_timeout+0x10e/0x160 [ 1032.253011] md_thread+0x97/0x160 [ 1032.253015] ? wait_woken+0x80/0x80 [ 1032.253019] kthread+0x104/0x140 [ 1032.253022] ? md_start_sync+0x60/0x60 [ 1032.253024] ? kthread_park+0x90/0x90 [ 1032.253027] ret_from_fork+0x35/0x40 This is because cache_size_mutex was unlocked too early in resize_stripes, which races with grow_one_stripe() that grow_one_stripe() allocates a stripe with wrong pool_size. Fix this issue by unlocking cache_size_mutex after updating pool_size. Cc: # v4.4+ Reported-by: KoWei Sung Signed-off-by: Song Liu Signed-off-by: Greg Kroah-Hartman

md/bitmap: md_bitmap_get_counter returns wrong blocks

2020-11-10T09:22:14Z

[ Upstream commit d837f7277f56e70d82b3a4a037d744854e62f387 ] md_bitmap_get_counter() has code: ``` if (bitmap->bp[page].hijacked || bitmap->bp[page].map == NULL) csize = ((sector_t)1) << (bitmap->chunkshift + PAGE_COUNTER_SHIFT - 1); ``` The minus 1 is wrong, this branch should report 2048 bits of space. With "-1" action, this only report 1024 bit of space. This bug code returns wrong blocks, but it doesn't inflence bitmap logic: 1. Most callers focus this function return value (the counter of offset), not the parameter blocks. 2. The bug is only triggered when hijacked is true or map is NULL. the hijacked true condition is very rare. the "map == null" only true when array is creating or resizing. 3. Even the caller gets wrong blocks, current code makes caller just to call md_bitmap_get_counter() one more time. Signed-off-by: Zhao Heming Signed-off-by: Song Liu Signed-off-by: Sasha Levin

bcache: fix a lost wake-up problem caused by mca_cannibalize_lock

2020-10-01T09:11:51Z

[ Upstream commit 34cf78bf34d48dddddfeeadb44f9841d7864997a ] This patch fix a lost wake-up problem caused by the race between mca_cannibalize_lock and bch_cannibalize_unlock. Consider two processes, A and B. Process A is executing mca_cannibalize_lock, while process B takes c->btree_cache_alloc_lock and is executing bch_cannibalize_unlock. The problem happens that after process A executes cmpxchg and will execute prepare_to_wait. In this timeslice process B executes wake_up, but after that process A executes prepare_to_wait and set the state to TASK_INTERRUPTIBLE. Then process A goes to sleep but no one will wake up it. This problem may cause bcache device to dead. Signed-off-by: Guoju Fang Signed-off-by: Coly Li Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

dm thin metadata: Avoid returning cmd->bm wild pointer on error

2020-09-12T09:45:31Z

commit 219403d7e56f9b716ad80ab87db85d29547ee73e upstream. Maybe __create_persistent_data_objects() caller will use PTR_ERR as a pointer, it will lead to some strange things. Signed-off-by: Ye Bin Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm cache metadata: Avoid returning cmd->bm wild pointer on error

2020-09-12T09:45:31Z

commit d16ff19e69ab57e08bf908faaacbceaf660249de upstream. Maybe __create_persistent_data_objects() caller will use PTR_ERR as a pointer, it will lead to some strange things. Signed-off-by: Ye Bin Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

bcache: allocate meta data pages as compound pages

2020-08-21T08:53:05Z

commit 5fe48867856367142d91a82f2cbf7a57a24cbb70 upstream. There are some meta data of bcache are allocated by multiple pages, and they are used as bio bv_page for I/Os to the cache device. for example cache_set->uuids, cache->disk_buckets, journal_write->data, bset_tree->data. For such meta data memory, all the allocated pages should be treated as a single memory block. Then the memory management and underlying I/O code can treat them more clearly. This patch adds __GFP_COMP flag to all the location allocating >0 order pages for the above mentioned meta data. Then their pages are treated as compound pages now. Signed-off-by: Coly Li Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

md/raid5: Fix Force reconstruct-write io stuck in degraded raid5

2020-08-21T08:53:05Z

commit a1c6ae3d9f3dd6aa5981a332a6f700cf1c25edef upstream. In degraded raid5, we need to read parity to do reconstruct-write when data disks fail. However, we can not read parity from handle_stripe_dirtying() in force reconstruct-write mode. Reproducible Steps: 1. Create degraded raid5 mdadm -C /dev/md2 --assume-clean -l5 -n3 /dev/sda2 /dev/sdb2 missing 2. Set rmw_level to 0 echo 0 > /sys/block/md2/md/rmw_level 3. IO to raid5 Now some io may be stuck in raid5. We can use handle_stripe_fill() to read the parity in this situation. Cc: # v4.4+ Reviewed-by: Alex Wu Reviewed-by: BingJing Chang Reviewed-by: Danny Shih Signed-off-by: ChangSyun Peng Signed-off-by: Song Liu Signed-off-by: Greg Kroah-Hartman

bcache: fix super block seq numbers comparision in register_cache_set()

2020-08-21T08:52:59Z

[ Upstream commit 117f636ea695270fe492d0c0c9dfadc7a662af47 ] In register_cache_set(), c is pointer to struct cache_set, and ca is pointer to struct cache, if ca->sb.seq > c->sb.seq, it means this registering cache has up to date version and other members, the in- memory version and other members should be updated to the newer value. But current implementation makes a cache set only has a single cache device, so the above assumption works well except for a special case. The execption is when a cache device new created and both ca->sb.seq and c->sb.seq are 0, because the super block is never flushed out yet. In the location for the following if() check, 2156 if (ca->sb.seq > c->sb.seq) { 2157 c->sb.version = ca->sb.version; 2158 memcpy(c->sb.set_uuid, ca->sb.set_uuid, 16); 2159 c->sb.flags = ca->sb.flags; 2160 c->sb.seq = ca->sb.seq; 2161 pr_debug("set version = %llu\n", c->sb.version); 2162 } c->sb.version is not initialized yet and valued 0. When ca->sb.seq is 0, the if() check will fail (because both values are 0), and the cache set version, set_uuid, flags and seq won't be updated. The above problem is hiden for current code, because the bucket size is compatible among different super block version. And the next time when running cache set again, ca->sb.seq will be larger than 0 and cache set super block version will be updated properly. But if the large bucket feature is enabled, sb->bucket_size is the low 16bits of the bucket size. For a power of 2 value, when the actual bucket size exceeds 16bit width, sb->bucket_size will always be 0. Then read_super_common() will fail because the if() check to is_power_of_2(sb->bucket_size) is false. This is how the long time hidden bug is triggered. This patch modifies the if() check to the following way, 2156 if (ca->sb.seq > c->sb.seq || c->sb.seq == 0) { Then cache set's version, set_uuid, flags and seq will always be updated corectly including for a new created cache device. Signed-off-by: Coly Li Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

bcache: fix potential deadlock problem in btree_gc_coalesce

2020-06-30T00:07:54Z

[ Upstream commit be23e837333a914df3f24bf0b32e87b0331ab8d1 ] coccicheck reports: drivers/md//bcache/btree.c:1538:1-7: preceding lock on line 1417 In btree_gc_coalesce func, if the coalescing process fails, we will goto to out_nocoalesce tag directly without releasing new_nodes[i]->write_lock. Then, it will cause a deadlock when trying to acquire new_nodes[i]-> write_lock for freeing new_nodes[i] before return. btree_gc_coalesce func details as follows: if alloc new_nodes[i] fails: goto out_nocoalesce; // obtain new_nodes[i]->write_lock mutex_lock(&new_nodes[i]->write_lock) // main coalescing process for (i = nodes - 1; i > 0; --i) [snipped] if coalescing process fails: // Here, directly goto out_nocoalesce // tag will cause a deadlock goto out_nocoalesce; [snipped] // release new_nodes[i]->write_lock mutex_unlock(&new_nodes[i]->write_lock) // coalesing succ, return return; out_nocoalesce: btree_node_free(new_nodes[i]) // free new_nodes[i] // obtain new_nodes[i]->write_lock mutex_lock(&new_nodes[i]->write_lock); // set flag for reuse clear_bit(BTREE_NODE_dirty, &ew_nodes[i]->flags); // release new_nodes[i]->write_lock mutex_unlock(&new_nodes[i]->write_lock); To fix the problem, we add a new tag 'out_unlock_nocoalesce' for releasing new_nodes[i]->write_lock before out_nocoalesce tag. If coalescing process fails, we will go to out_unlock_nocoalesce tag for releasing new_nodes[i]->write_lock before free new_nodes[i] in out_nocoalesce tag. (Coly Li helps to clean up commit log format.) Fixes: 2a285686c109816 ("bcache: btree locking rework") Signed-off-by: Zhiqiang Liu Signed-off-by: Coly Li Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

md: don't flush workqueue unconditionally in md_open

2020-06-20T08:23:21Z

[ Upstream commit f6766ff6afff70e2aaf39e1511e16d471de7c3ae ] We need to check mddev->del_work before flush workqueu since the purpose of flush is to ensure the previous md is disappeared. Otherwise the similar deadlock appeared if LOCKDEP is enabled, it is due to md_open holds the bdev->bd_mutex before flush workqueue. kernel: [ 154.522645] ====================================================== kernel: [ 154.522647] WARNING: possible circular locking dependency detected kernel: [ 154.522650] 5.6.0-rc7-lp151.27-default #25 Tainted: G O kernel: [ 154.522651] ------------------------------------------------------ kernel: [ 154.522653] mdadm/2482 is trying to acquire lock: kernel: [ 154.522655] ffff888078529128 ((wq_completion)md_misc){+.+.}, at: flush_workqueue+0x84/0x4b0 kernel: [ 154.522673] kernel: [ 154.522673] but task is already holding lock: kernel: [ 154.522675] ffff88804efa9338 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x79/0x590 kernel: [ 154.522691] kernel: [ 154.522691] which lock already depends on the new lock. kernel: [ 154.522691] kernel: [ 154.522694] kernel: [ 154.522694] the existing dependency chain (in reverse order) is: kernel: [ 154.522696] kernel: [ 154.522696] -> #4 (&bdev->bd_mutex){+.+.}: kernel: [ 154.522704] __mutex_lock+0x87/0x950 kernel: [ 154.522706] __blkdev_get+0x79/0x590 kernel: [ 154.522708] blkdev_get+0x65/0x140 kernel: [ 154.522709] blkdev_get_by_dev+0x2f/0x40 kernel: [ 154.522716] lock_rdev+0x3d/0x90 [md_mod] kernel: [ 154.522719] md_import_device+0xd6/0x1b0 [md_mod] kernel: [ 154.522723] new_dev_store+0x15e/0x210 [md_mod] kernel: [ 154.522728] md_attr_store+0x7a/0xc0 [md_mod] kernel: [ 154.522732] kernfs_fop_write+0x117/0x1b0 kernel: [ 154.522735] vfs_write+0xad/0x1a0 kernel: [ 154.522737] ksys_write+0xa4/0xe0 kernel: [ 154.522745] do_syscall_64+0x64/0x2b0 kernel: [ 154.522748] entry_SYSCALL_64_after_hwframe+0x49/0xbe kernel: [ 154.522749] kernel: [ 154.522749] -> #3 (&mddev->reconfig_mutex){+.+.}: kernel: [ 154.522752] __mutex_lock+0x87/0x950 kernel: [ 154.522756] new_dev_store+0xc9/0x210 [md_mod] kernel: [ 154.522759] md_attr_store+0x7a/0xc0 [md_mod] kernel: [ 154.522761] kernfs_fop_write+0x117/0x1b0 kernel: [ 154.522763] vfs_write+0xad/0x1a0 kernel: [ 154.522765] ksys_write+0xa4/0xe0 kernel: [ 154.522767] do_syscall_64+0x64/0x2b0 kernel: [ 154.522769] entry_SYSCALL_64_after_hwframe+0x49/0xbe kernel: [ 154.522770] kernel: [ 154.522770] -> #2 (kn->count#253){++++}: kernel: [ 154.522775] __kernfs_remove+0x253/0x2c0 kernel: [ 154.522778] kernfs_remove+0x1f/0x30 kernel: [ 154.522780] kobject_del+0x28/0x60 kernel: [ 154.522783] mddev_delayed_delete+0x24/0x30 [md_mod] kernel: [ 154.522786] process_one_work+0x2a7/0x5f0 kernel: [ 154.522788] worker_thread+0x2d/0x3d0 kernel: [ 154.522793] kthread+0x117/0x130 kernel: [ 154.522795] ret_from_fork+0x3a/0x50 kernel: [ 154.522796] kernel: [ 154.522796] -> #1 ((work_completion)(&mddev->del_work)){+.+.}: kernel: [ 154.522800] process_one_work+0x27e/0x5f0 kernel: [ 154.522802] worker_thread+0x2d/0x3d0 kernel: [ 154.522804] kthread+0x117/0x130 kernel: [ 154.522806] ret_from_fork+0x3a/0x50 kernel: [ 154.522807] kernel: [ 154.522807] -> #0 ((wq_completion)md_misc){+.+.}: kernel: [ 154.522813] __lock_acquire+0x1392/0x1690 kernel: [ 154.522816] lock_acquire+0xb4/0x1a0 kernel: [ 154.522818] flush_workqueue+0xab/0x4b0 kernel: [ 154.522821] md_open+0xb6/0xc0 [md_mod] kernel: [ 154.522823] __blkdev_get+0xea/0x590 kernel: [ 154.522825] blkdev_get+0x65/0x140 kernel: [ 154.522828] do_dentry_open+0x1d1/0x380 kernel: [ 154.522831] path_openat+0x567/0xcc0 kernel: [ 154.522834] do_filp_open+0x9b/0x110 kernel: [ 154.522836] do_sys_openat2+0x201/0x2a0 kernel: [ 154.522838] do_sys_open+0x57/0x80 kernel: [ 154.522840] do_syscall_64+0x64/0x2b0 kernel: [ 154.522842] entry_SYSCALL_64_after_hwframe+0x49/0xbe kernel: [ 154.522844] kernel: [ 154.522844] other info that might help us debug this: kernel: [ 154.522844] kernel: [ 154.522846] Chain exists of: kernel: [ 154.522846] (wq_completion)md_misc --> &mddev->reconfig_mutex --> &bdev->bd_mutex kernel: [ 154.522846] kernel: [ 154.522850] Possible unsafe locking scenario: kernel: [ 154.522850] kernel: [ 154.522852] CPU0 CPU1 kernel: [ 154.522853] ---- ---- kernel: [ 154.522854] lock(&bdev->bd_mutex); kernel: [ 154.522856] lock(&mddev->reconfig_mutex); kernel: [ 154.522858] lock(&bdev->bd_mutex); kernel: [ 154.522860] lock((wq_completion)md_misc); kernel: [ 154.522861] kernel: [ 154.522861] *** DEADLOCK *** kernel: [ 154.522861] kernel: [ 154.522864] 1 lock held by mdadm/2482: kernel: [ 154.522865] #0: ffff88804efa9338 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x79/0x590 kernel: [ 154.522868] kernel: [ 154.522868] stack backtrace: kernel: [ 154.522873] CPU: 1 PID: 2482 Comm: mdadm Tainted: G O 5.6.0-rc7-lp151.27-default #25 kernel: [ 154.522875] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 kernel: [ 154.522878] Call Trace: kernel: [ 154.522881] dump_stack+0x8f/0xcb kernel: [ 154.522884] check_noncircular+0x194/0x1b0 kernel: [ 154.522888] ? __lock_acquire+0x1392/0x1690 kernel: [ 154.522890] __lock_acquire+0x1392/0x1690 kernel: [ 154.522893] lock_acquire+0xb4/0x1a0 kernel: [ 154.522895] ? flush_workqueue+0x84/0x4b0 kernel: [ 154.522898] flush_workqueue+0xab/0x4b0 kernel: [ 154.522900] ? flush_workqueue+0x84/0x4b0 kernel: [ 154.522905] ? md_open+0xb6/0xc0 [md_mod] kernel: [ 154.522908] md_open+0xb6/0xc0 [md_mod] kernel: [ 154.522910] __blkdev_get+0xea/0x590 kernel: [ 154.522912] ? bd_acquire+0xc0/0xc0 kernel: [ 154.522914] blkdev_get+0x65/0x140 kernel: [ 154.522916] ? bd_acquire+0xc0/0xc0 kernel: [ 154.522918] do_dentry_open+0x1d1/0x380 kernel: [ 154.522921] path_openat+0x567/0xcc0 kernel: [ 154.522923] ? __lock_acquire+0x380/0x1690 kernel: [ 154.522926] do_filp_open+0x9b/0x110 kernel: [ 154.522929] ? __alloc_fd+0xe5/0x1f0 kernel: [ 154.522935] ? kmem_cache_alloc+0x28c/0x630 kernel: [ 154.522939] ? do_sys_openat2+0x201/0x2a0 kernel: [ 154.522941] do_sys_openat2+0x201/0x2a0 kernel: [ 154.522944] do_sys_open+0x57/0x80 kernel: [ 154.522946] do_syscall_64+0x64/0x2b0 kernel: [ 154.522948] entry_SYSCALL_64_after_hwframe+0x49/0xbe kernel: [ 154.522951] RIP: 0033:0x7f98d279d9ae And md_alloc also flushed the same workqueue, but the thing is different here. Because all the paths call md_alloc don't hold bdev->bd_mutex, and the flush is necessary to avoid race condition, so leave it as it is. Signed-off-by: Guoqing Jiang Signed-off-by: Song Liu Signed-off-by: Sasha Levin