kernel/linux.git/drivers/md, branch v4.4.235

bcache: allocate meta data pages as compound pages

2020-08-21T08:53:05+00:00

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

2020-08-21T08:53:05+00:00

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()

2020-08-21T08:52:59+00:00

[ 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

2020-06-30T00:07:54+00:00

[ 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

2020-06-20T08:23:21+00:00

[ 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

dm: fix second blk_delay_queue() parameter to be in msec units not jiffies

2020-05-10T08:26:25+00:00

commit bd9f55ea1cf6e14eb054b06ea877d2d1fa339514 upstream. Commit d548b34b062 ("dm: reduce the queue delay used in dm_request_fn from 100ms to 10ms") always intended the value to be 10 msecs -- it just expressed it in jiffies because earlier commit 7eaceaccab ("block: remove per-queue plugging") did. Signed-off-by: Tahsin Erdogan Signed-off-by: Mike Snitzer Fixes: d548b34b062 ("dm: reduce the queue delay used in dm_request_fn from 100ms to 10ms") Cc: stable@vger.kernel.org # 4.1+ -- stable@ backports must be applied to drivers/md/dm.c Signed-off-by: Greg Kroah-Hartman

dm flakey: check for null arg_name in parse_features()

2020-04-24T05:57:20+00:00

[ Upstream commit 7690e25302dc7d0cd42b349e746fe44b44a94f2b ] One can crash dm-flakey by specifying more feature arguments than the number of features supplied. Checking for null in arg_name avoids this. dmsetup create flakey-test --table "0 66076080 flakey /dev/sdb9 0 0 180 2 drop_writes" Signed-off-by: Goldwyn Rodrigues Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin

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

2020-03-11T06:51:19+00:00

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

bcache: explicity type cast in bset_bkey_last()

2020-02-28T14:39:09+00:00

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

dm: fix potential for q->make_request_fn NULL pointer

2020-02-14T21:30:02+00:00

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