linux.git/block, branch v4.9.113

block/mq: fix potential deadlock during cpu hotplug

2018-04-24T07:34:18+00:00

commit 51d638b1f56a0bfd9219800620994794a1a2b219 upstream.

This can be triggered by hot-unplug one cpu.

======================================================
 [ INFO: possible circular locking dependency detected ]
 4.11.0+ #17 Not tainted
 -------------------------------------------------------
 step_after_susp/2640 is trying to acquire lock:
  (all_q_mutex){+.+...}, at: [] blk_mq_queue_reinit_work+0x18/0x110

 but task is already holding lock:
  (cpu_hotplug.lock){+.+.+.}, at: [] cpu_hotplug_begin+0x7f/0xe0

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (cpu_hotplug.lock){+.+.+.}:
        lock_acquire+0x11c/0x230
        __mutex_lock+0x92/0x990
        mutex_lock_nested+0x1b/0x20
        get_online_cpus+0x64/0x80
        blk_mq_init_allocated_queue+0x3a0/0x4e0
        blk_mq_init_queue+0x3a/0x60
        loop_add+0xe5/0x280
        loop_init+0x124/0x177
        do_one_initcall+0x53/0x1c0
        kernel_init_freeable+0x1e3/0x27f
        kernel_init+0xe/0x100
        ret_from_fork+0x31/0x40

 -> #0 (all_q_mutex){+.+...}:
        __lock_acquire+0x189a/0x18a0
        lock_acquire+0x11c/0x230
        __mutex_lock+0x92/0x990
        mutex_lock_nested+0x1b/0x20
        blk_mq_queue_reinit_work+0x18/0x110
        blk_mq_queue_reinit_dead+0x1c/0x20
        cpuhp_invoke_callback+0x1f2/0x810
        cpuhp_down_callbacks+0x42/0x80
        _cpu_down+0xb2/0xe0
        freeze_secondary_cpus+0xb6/0x390
        suspend_devices_and_enter+0x3b3/0xa40
        pm_suspend+0x129/0x490
        state_store+0x82/0xf0
        kobj_attr_store+0xf/0x20
        sysfs_kf_write+0x45/0x60
        kernfs_fop_write+0x135/0x1c0
        __vfs_write+0x37/0x160
        vfs_write+0xcd/0x1d0
        SyS_write+0x58/0xc0
        do_syscall_64+0x8f/0x710
        return_from_SYSCALL_64+0x0/0x7a

 other info that might help us debug this:

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(cpu_hotplug.lock);
                                lock(all_q_mutex);
                                lock(cpu_hotplug.lock);
   lock(all_q_mutex);

  *** DEADLOCK ***

 8 locks held by step_after_susp/2640:
  #0:  (sb_writers#6){.+.+.+}, at: [] vfs_write+0x1ad/0x1d0
  #1:  (&of->mutex){+.+.+.}, at: [] kernfs_fop_write+0x101/0x1c0
  #2:  (s_active#166){.+.+.+}, at: [] kernfs_fop_write+0x109/0x1c0
  #3:  (pm_mutex){+.+...}, at: [] pm_suspend+0x21d/0x490
  #4:  (acpi_scan_lock){+.+.+.}, at: [] acpi_scan_lock_acquire+0x17/0x20
  #5:  (cpu_add_remove_lock){+.+.+.}, at: [] freeze_secondary_cpus+0x27/0x390
  #6:  (cpu_hotplug.dep_map){++++++}, at: [] cpu_hotplug_begin+0x5/0xe0
  #7:  (cpu_hotplug.lock){+.+.+.}, at: [] cpu_hotplug_begin+0x7f/0xe0

 stack backtrace:
 CPU: 3 PID: 2640 Comm: step_after_susp Not tainted 4.11.0+ #17
 Hardware name: Dell Inc. OptiPlex 7040/0JCTF8, BIOS 1.4.9 09/12/2016
 Call Trace:
  dump_stack+0x99/0xce
  print_circular_bug+0x1fa/0x270
  __lock_acquire+0x189a/0x18a0
  lock_acquire+0x11c/0x230
  ? lock_acquire+0x11c/0x230
  ? blk_mq_queue_reinit_work+0x18/0x110
  ? blk_mq_queue_reinit_work+0x18/0x110
  __mutex_lock+0x92/0x990
  ? blk_mq_queue_reinit_work+0x18/0x110
  ? kmem_cache_free+0x2cb/0x330
  ? anon_transport_class_unregister+0x20/0x20
  ? blk_mq_queue_reinit_work+0x110/0x110
  mutex_lock_nested+0x1b/0x20
  ? mutex_lock_nested+0x1b/0x20
  blk_mq_queue_reinit_work+0x18/0x110
  blk_mq_queue_reinit_dead+0x1c/0x20
  cpuhp_invoke_callback+0x1f2/0x810
  ? __flow_cache_shrink+0x160/0x160
  cpuhp_down_callbacks+0x42/0x80
  _cpu_down+0xb2/0xe0
  freeze_secondary_cpus+0xb6/0x390
  suspend_devices_and_enter+0x3b3/0xa40
  ? rcu_read_lock_sched_held+0x79/0x80
  pm_suspend+0x129/0x490
  state_store+0x82/0xf0
  kobj_attr_store+0xf/0x20
  sysfs_kf_write+0x45/0x60
  kernfs_fop_write+0x135/0x1c0
  __vfs_write+0x37/0x160
  ? rcu_read_lock_sched_held+0x79/0x80
  ? rcu_sync_lockdep_assert+0x2f/0x60
  ? __sb_start_write+0xd9/0x1c0
  ? vfs_write+0x1ad/0x1d0
  vfs_write+0xcd/0x1d0
  SyS_write+0x58/0xc0
  ? rcu_read_lock_sched_held+0x79/0x80
  do_syscall_64+0x8f/0x710
  ? trace_hardirqs_on_thunk+0x1a/0x1c
  entry_SYSCALL64_slow_path+0x25/0x25

The cpu hotplug path will hold cpu_hotplug.lock and then reinit all exiting
queues for blk mq w/ all_q_mutex, however, blk_mq_init_allocated_queue() will
contend these two locks in the inversion order. This is due to commit eabe06595d62
(blk/mq: Cure cpu hotplug lock inversion), it fixes a cpu hotplug lock inversion
issue because of hotplug rework, however the hotplug rework is still work-in-progress
and lives in a -tip branch and mainline cannot yet trigger that splat. The commit
breaks the linus's tree in the merge window, so this patch reverts the lock order
and avoids to splat linus's tree.

Cc: Jens Axboe 
Cc: Peter Zijlstra (Intel) 
Cc: Thomas Gleixner 
Signed-off-by: Wanpeng Li 
Signed-off-by: Jens Axboe 
Cc: Thierry Escande 
Signed-off-by: Greg Kroah-Hartman

blk-mq: fix kernel oops in blk_mq_tag_idle()

2018-04-13T17:48:30+00:00

[ Upstream commit 8ab0b7dc73e1b3e2987d42554b2bff503f692772 ]

HW queues may be unmapped in some cases, such as blk_mq_update_nr_hw_queues(),
then we need to check it before calling blk_mq_tag_idle(), otherwise
the following kernel oops can be triggered, so fix it by checking if
the hw queue is unmapped since it doesn't make sense to idle the tags
any more after hw queues are unmapped.

[  440.771298] Workqueue: nvme-wq nvme_rdma_del_ctrl_work [nvme_rdma]
[  440.779104] task: ffff894bae755ee0 ti: ffff893bf9bc8000 task.ti: ffff893bf9bc8000
[  440.788359] RIP: 0010:[]  [] __blk_mq_tag_idle+0x24/0x40
[  440.798697] RSP: 0018:ffff893bf9bcbd10  EFLAGS: 00010286
[  440.805538] RAX: 0000000000000000 RBX: ffff895bb131dc00 RCX: 000000000000011f
[  440.814426] RDX: 00000000ffffffff RSI: 0000000000000120 RDI: ffff895bb131dc00
[  440.823301] RBP: ffff893bf9bcbd10 R08: 000000000001b860 R09: 4a51d361c00c0000
[  440.832193] R10: b5907f32b4cc7003 R11: ffffd6cabfb57000 R12: ffff894bafd1e008
[  440.841091] R13: 0000000000000001 R14: ffff895baf770000 R15: 0000000000000080
[  440.849988] FS:  0000000000000000(0000) GS:ffff894bbdcc0000(0000) knlGS:0000000000000000
[  440.859955] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  440.867274] CR2: 0000000000000008 CR3: 000000103d098000 CR4: 00000000001407e0
[  440.876169] Call Trace:
[  440.879818]  [] blk_mq_exit_hctx+0xd8/0xe0
[  440.887051]  [] blk_mq_free_queue+0xf0/0x160
[  440.894465]  [] blk_cleanup_queue+0xd9/0x150
[  440.901881]  [] nvme_ns_remove+0x5b/0xb0 [nvme_core]
[  440.910068]  [] nvme_remove_namespaces+0x3b/0x60 [nvme_core]
[  440.919026]  [] __nvme_rdma_remove_ctrl+0x2b/0xb0 [nvme_rdma]
[  440.928079]  [] nvme_rdma_del_ctrl_work+0x17/0x20 [nvme_rdma]
[  440.937126]  [] process_one_work+0x17a/0x440
[  440.944517]  [] worker_thread+0x278/0x3c0
[  440.951607]  [] ? manage_workers.isra.24+0x2a0/0x2a0
[  440.959760]  [] kthread+0xcf/0xe0
[  440.966055]  [] ? insert_kthread_work+0x40/0x40
[  440.973715]  [] ret_from_fork+0x58/0x90
[  440.980586]  [] ? insert_kthread_work+0x40/0x40
[  440.988229] Code: 5b 41 5c 5d c3 66 90 0f 1f 44 00 00 48 8b 87 20 01 00 00 f0 0f ba 77 40 01 19 d2 85 d2 75 08 c3 0f 1f 80 00 00 00 00 55 48 89 e5  ff 48 08 48 8d 78 10 e8 7f 0f 05 00 5d c3 0f 1f 00 66 2e 0f
[  441.011620] RIP  [] __blk_mq_tag_idle+0x24/0x40
[  441.019301]  RSP 
[  441.024052] CR2: 0000000000000008

Reported-by: Zhang Yi 
Tested-by: Zhang Yi 
Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

bio-integrity: Do not allocate integrity context for bio w/o data

2018-04-13T17:48:18+00:00

[ Upstream commit 3116a23bb30272d74ea81baf5d0ee23f602dd15b ]

If bio has no data, such as ones from blkdev_issue_flush(),
then we have nothing to protect.

This patch prevent bugon like follows:

kfree_debugcheck: out of range ptr ac1fa1d106742a5ah
kernel BUG at mm/slab.c:2773!
invalid opcode: 0000 [#1] SMP
Modules linked in: bcache
CPU: 0 PID: 4428 Comm: xfs_io Tainted: G        W       4.11.0-rc4-ext4-00041-g2ef0043-dirty #43
Hardware name: Virtuozzo KVM, BIOS seabios-1.7.5-11.vz7.4 04/01/2014
task: ffff880137786440 task.stack: ffffc90000ba8000
RIP: 0010:kfree_debugcheck+0x25/0x2a
RSP: 0018:ffffc90000babde0 EFLAGS: 00010082
RAX: 0000000000000034 RBX: ac1fa1d106742a5a RCX: 0000000000000007
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88013f3ccb40
RBP: ffffc90000babde8 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000fcb76420 R11: 00000000725172ed R12: 0000000000000282
R13: ffffffff8150e766 R14: ffff88013a145e00 R15: 0000000000000001
FS:  00007fb09384bf40(0000) GS:ffff88013f200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd0172f9e40 CR3: 0000000137fa9000 CR4: 00000000000006f0
Call Trace:
 kfree+0xc8/0x1b3
 bio_integrity_free+0xc3/0x16b
 bio_free+0x25/0x66
 bio_put+0x14/0x26
 blkdev_issue_flush+0x7a/0x85
 blkdev_fsync+0x35/0x42
 vfs_fsync_range+0x8e/0x9f
 vfs_fsync+0x1c/0x1e
 do_fsync+0x31/0x4a
 SyS_fsync+0x10/0x14
 entry_SYSCALL_64_fastpath+0x1f/0xc2

Reviewed-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Martin K. Petersen 
Signed-off-by: Dmitry Monakhov 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

blk-mq: fix race between updating nr_hw_queues and switching io sched

2018-04-13T17:48:11+00:00

[ Upstream commit fb350e0ad99359768e1e80b4784692031ec340e4 ]

In both elevator_switch_mq() and blk_mq_update_nr_hw_queues(), sched tags
can be allocated, and q->nr_hw_queue is used, and race is inevitable, for
example: blk_mq_init_sched() may trigger use-after-free on hctx, which is
freed in blk_mq_realloc_hw_ctxs() when nr_hw_queues is decreased.

This patch fixes the race be holding q->sysfs_lock.

Reviewed-by: Christoph Hellwig 
Reported-by: Yi Zhang 
Tested-by: Yi Zhang 
Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

block: fix an error code in add_partition()

2018-04-13T17:48:04+00:00

[ Upstream commit 7bd897cfce1eb373892d35d7f73201b0f9b221c4 ]

We don't set an error code on this path.  It means that we return NULL
instead of an error pointer and the caller does a NULL dereference.

Fixes: 6d1d8050b4bc ("block, partition: add partition_meta_info to hd_struct")
Signed-off-by: Dan Carpenter 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

blk-mq: NVMe 512B/4K+T10 DIF/DIX format returns I/O error on dd with split op

2018-04-13T17:47:54+00:00

[ Upstream commit f36ea50ca0043e7b1204feaf1d2ba6bd68c08d36 ]

When formatting NVMe to 512B/4K + T10 DIf/DIX, dd with split op returns
"Input/output error". Looks block layer split the bio after calling
bio_integrity_prep(bio). This patch fixes the issue.

Below is how we debug this issue:
(1)format nvme to 4K block # size with type 2 DIF
(2)dd with block size bigger than 1024k.
oflag=direct
dd: error writing '/dev/nvme0n1': Input/output error

We added some debug code in nvme device driver. It showed us the first
op and the second op have the same bi and pi address. This is not
correct.

1st op: nvme0n1 Op:Wr slba 0x505 length 0x100, PI ctrl=0x1400,
	dsmgmt=0x0, AT=0x0 & RT=0x505
	Guard 0x00b1, AT 0x0000, RT physical 0x00000505 RT virtual 0x00002828

2nd op: nvme0n1 Op:Wr slba 0x605 length 0x1, PI ctrl=0x1400, dsmgmt=0x0,
	AT=0x0 & RT=0x605  ==> This op fails and subsequent 5 retires..
	Guard 0x00b1, AT 0x0000, RT physical 0x00000605 RT virtual 0x00002828

With the fix, It showed us both of the first op and the second op have
correct bi and pi address.

1st op: nvme2n1 Op:Wr slba 0x505 length 0x100, PI ctrl=0x1400,
	dsmgmt=0x0, AT=0x0 & RT=0x505
	Guard 0x5ccb, AT 0x0000, RT physical 0x00000505 RT virtual
	0x00002828
2nd op: nvme2n1 Op:Wr slba 0x605 length 0x1, PI ctrl=0x1400, dsmgmt=0x0,
	AT=0x0 & RT=0x605
	Guard 0xab4c, AT 0x0000, RT physical 0x00000605 RT virtual
	0x00003028

Signed-off-by: Wen Xiong 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Fix slab name "biovec-(1<<(21-12))"

2018-04-08T10:13:00+00:00

commit bd5c4facf59648581d2f1692dad7b107bf429954 upstream.

I'm getting a slab named "biovec-(1<<(21-12))". It is caused by unintended
expansion of the macro BIO_MAX_PAGES. This patch renames it to biovec-max.

Signed-off-by: Mikulas Patocka 
Cc: stable@vger.kernel.org	# v4.14+
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

partitions/msdos: Unable to mount UFS 44bsd partitions

2018-04-08T10:12:42+00:00

commit 5f15684bd5e5ef39d4337988864fec8012471dda upstream.

UFS partitions from newer versions of FreeBSD 10 and 11 use relative
addressing for their subpartitions. But older versions of FreeBSD still
use absolute addressing just like OpenBSD and NetBSD.

Instead of simply testing for a FreeBSD partition, the code needs to
also test if the starting offset of the C subpartition is zero.

https://bugzilla.kernel.org/show_bug.cgi?id=197733

Signed-off-by: Richard Narron 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

block/mq: Cure cpu hotplug lock inversion

2018-03-24T10:00:22+00:00

[ Upstream commit eabe06595d62cfa9278e2cd012df614bc68a7042 ]

By poking at /debug/sched_features I triggered the following splat:

 [] ======================================================
 [] WARNING: possible circular locking dependency detected
 [] 4.11.0-00873-g964c8b7-dirty #694 Not tainted
 [] ------------------------------------------------------
 [] bash/2109 is trying to acquire lock:
 []  (cpu_hotplug_lock.rw_sem){++++++}, at: [] static_key_slow_dec+0x1b/0x50
 []
 [] but task is already holding lock:
 []  (&sb->s_type->i_mutex_key#4){+++++.}, at: [] sched_feat_write+0x86/0x170
 []
 [] which lock already depends on the new lock.
 []
 []
 [] the existing dependency chain (in reverse order) is:
 []
 [] -> #2 (&sb->s_type->i_mutex_key#4){+++++.}:
 []        lock_acquire+0x100/0x210
 []        down_write+0x28/0x60
 []        start_creating+0x5e/0xf0
 []        debugfs_create_dir+0x13/0x110
 []        blk_mq_debugfs_register+0x21/0x70
 []        blk_mq_register_dev+0x64/0xd0
 []        blk_register_queue+0x6a/0x170
 []        device_add_disk+0x22d/0x440
 []        loop_add+0x1f3/0x280
 []        loop_init+0x104/0x142
 []        do_one_initcall+0x43/0x180
 []        kernel_init_freeable+0x1de/0x266
 []        kernel_init+0xe/0x100
 []        ret_from_fork+0x31/0x40
 []
 [] -> #1 (all_q_mutex){+.+.+.}:
 []        lock_acquire+0x100/0x210
 []        __mutex_lock+0x6c/0x960
 []        mutex_lock_nested+0x1b/0x20
 []        blk_mq_init_allocated_queue+0x37c/0x4e0
 []        blk_mq_init_queue+0x3a/0x60
 []        loop_add+0xe5/0x280
 []        loop_init+0x104/0x142
 []        do_one_initcall+0x43/0x180
 []        kernel_init_freeable+0x1de/0x266
 []        kernel_init+0xe/0x100
 []        ret_from_fork+0x31/0x40

 []  *** DEADLOCK ***
 []
 [] 3 locks held by bash/2109:
 []  #0:  (sb_writers#11){.+.+.+}, at: [] vfs_write+0x17d/0x1a0
 []  #1:  (debugfs_srcu){......}, at: [] full_proxy_write+0x5d/0xd0
 []  #2:  (&sb->s_type->i_mutex_key#4){+++++.}, at: [] sched_feat_write+0x86/0x170
 []
 [] stack backtrace:
 [] CPU: 9 PID: 2109 Comm: bash Not tainted 4.11.0-00873-g964c8b7-dirty #694
 [] Hardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013
 [] Call Trace:

 []  lock_acquire+0x100/0x210
 []  get_online_cpus+0x2a/0x90
 []  static_key_slow_dec+0x1b/0x50
 []  static_key_disable+0x20/0x30
 []  sched_feat_write+0x131/0x170
 []  full_proxy_write+0x97/0xd0
 []  __vfs_write+0x28/0x120
 []  vfs_write+0xb5/0x1a0
 []  SyS_write+0x49/0xa0
 []  entry_SYSCALL_64_fastpath+0x23/0xc2

This is because of the cpu hotplug lock rework. Break the chain at #1
by reversing the lock acquisition order. This way i_mutex_key#4 no
longer depends on cpu_hotplug_lock and things are good.

Cc: Jens Axboe 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

blk-throttle: make sure expire time isn't too big

2018-03-22T08:17:44+00:00

[ Upstream commit 06cceedcca67a93ac7f7aa93bbd9980c7496d14e ]

cgroup could be throttled to a limit but when all cgroups cross high
limit, queue enters a higher state and so the group should be throttled
to a higher limit. It's possible the cgroup is sleeping because of
throttle and other cgroups don't dispatch IO any more. In this case,
nobody can trigger current downgrade/upgrade logic. To fix this issue,
we could either set up a timer to wakeup the cgroup if other cgroups are
idle or make sure this cgroup doesn't sleep too long. Setting up a timer
means we must change the timer very frequently. This patch chooses the
latter. Making cgroup sleep time not too big wouldn't change cgroup
bps/iops, but could make it wakeup more frequently, which isn't a big
issue because throtl_slice * 8 is already quite big.

Signed-off-by: Shaohua Li 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman