linux-stable.git/drivers/md/md.c, branch linux-5.7.y

md: raid0/linear: fix dereference before null check on pointer mddev

2020-08-19T06:23:32+00:00

[ Upstream commit 9a5a85972c073f720d81a7ebd08bfe278e6e16db ]

Pointer mddev is being dereferenced with a test_bit call before mddev
is being null checked, this may cause a null pointer dereference. Fix
this by moving the null pointer checks to sanity check mddev before
it is dereferenced.

Addresses-Coverity: ("Dereference before null check")
Fixes: 62f7b1989c02 ("md raid0/linear: Mark array as 'broken' and fail BIOs if a member is gone")
Signed-off-by: Colin Ian King 
Reviewed-by: Guilherme G. Piccoli 
Signed-off-by: Song Liu 
Signed-off-by: Sasha Levin

md: don't flush workqueue unconditionally in md_open

2020-06-22T07:32:44+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

Merge tag 'for-5.7/drivers-2020-03-29' of git://git.kernel.dk/linux-block

2020-03-30T18:43:51+00:00

Pull block driver updates from Jens Axboe:

 - floppy driver cleanup series from Willy

 - NVMe updates and fixes (Various)

 - null_blk trace improvements (Chaitanya)

 - bcache fixes (Coly)

 - md fixes (via Song)

 - loop block size change optimizations (Martijn)

 - scnprintf() use (Takashi)

* tag 'for-5.7/drivers-2020-03-29' of git://git.kernel.dk/linux-block: (81 commits)
  null_blk: add trace in null_blk_zoned.c
  null_blk: add tracepoint helpers for zoned mode
  block: add a zone condition debug helper
  nvme: cleanup namespace identifier reporting in nvme_init_ns_head
  nvme: rename __nvme_find_ns_head to nvme_find_ns_head
  nvme: refactor nvme_identify_ns_descs error handling
  nvme-tcp: Add warning on state change failure at nvme_tcp_setup_ctrl
  nvme-rdma: Add warning on state change failure at nvme_rdma_setup_ctrl
  nvme: Fix controller creation races with teardown flow
  nvme: Make nvme_uninit_ctrl symmetric to nvme_init_ctrl
  nvme: Fix ctrl use-after-free during sysfs deletion
  nvme-pci: Re-order nvme_pci_free_ctrl
  nvme: Remove unused return code from nvme_delete_ctrl_sync
  nvme: Use nvme_state_terminal helper
  nvme: release ida resources
  nvme: Add compat_ioctl handler for NVME_IOCTL_SUBMIT_IO
  nvmet-tcp: optimize tcp stack TX when data digest is used
  nvme-fabrics: Use scnprintf() for avoiding potential buffer overflow
  nvme-multipath: do not reset on unknown status
  nvmet-rdma: allocate RW ctxs according to mdts
  ...

block: simplify queue allocation

2020-03-27T16:23:43+00:00

Current make_request based drivers use either blk_alloc_queue_node or
blk_alloc_queue to allocate a queue, and then set up the make_request_fn
function pointer and a few parameters using the blk_queue_make_request
helper.  Simplify this by passing the make_request pointer to
blk_alloc_queue, and while at it merge the _node variant into the main
helper by always passing a node_id, and remove the superfluous gfp_mask
parameter.  A lower-level __blk_alloc_queue is kept for the blk-mq case.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: move the part_stat* helpers from genhd.h to a new header

2020-03-25T15:50:09+00:00

These macros are just used by a few files.  Move them out of genhd.h,
which is included everywhere into a new standalone header.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: cleanup how md_autodetect_dev is called

2020-03-24T13:57:08+00:00

Add a new include/linux/raid/detect.h header to declare the
md_autodetect_dev prototype which can be shared between md and
the partition code.  Then use IS_BUILTIN to call it instead of the
ifdef magic.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: remove __bdevname

2020-03-24T13:57:07+00:00

There is no good reason for __bdevname to exist.  Just open code
printing the string in the callers.  For three of them the format
string can be trivially merged into existing printk statements,
and in init/do_mounts.c we can at least do the scnprintf once at
the start of the function, and unconditional of CONFIG_BLOCK to
make the output for tiny configfs a little more helpful.

Acked-by: Theodore Ts'o  # for ext4
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

md: check arrays is suspended in mddev_detach before call quiesce operations

2020-03-17T17:53:07+00:00

Don't call quiesce(1) and quiesce(0) if array is already suspended,
otherwise in level_store, the array is writable after mddev_detach
in below part though the intention is to make array writable after
resume.

	mddev_suspend(mddev);
	mddev_detach(mddev);
	...
	mddev_resume(mddev);

And it also causes calltrace as follows in [1].

[48005.653834] WARNING: CPU: 1 PID: 45380 at kernel/kthread.c:510 kthread_park+0x77/0x90
[...]
[48005.653976] CPU: 1 PID: 45380 Comm: mdadm Tainted: G           OE     5.4.10-arch1-1 #1
[48005.653979] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./J4105-ITX, BIOS P1.40 08/06/2018
[48005.653984] RIP: 0010:kthread_park+0x77/0x90
[48005.654015] Call Trace:
[48005.654039]  r5l_quiesce+0x3c/0x70 [raid456]
[48005.654052]  raid5_quiesce+0x228/0x2e0 [raid456]
[48005.654073]  mddev_detach+0x30/0x70 [md_mod]
[48005.654090]  level_store+0x202/0x670 [md_mod]
[48005.654099]  ? security_capable+0x40/0x60
[48005.654114]  md_attr_store+0x7b/0xc0 [md_mod]
[48005.654123]  kernfs_fop_write+0xce/0x1b0
[48005.654132]  vfs_write+0xb6/0x1a0
[48005.654138]  ksys_write+0x67/0xe0
[48005.654146]  do_syscall_64+0x4e/0x140
[48005.654155]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[48005.654161] RIP: 0033:0x7fa0c8737497

[1]: https://bugzilla.kernel.org/show_bug.cgi?id=206161

Signed-off-by: Guoqing Jiang 
Signed-off-by: Song Liu

proc: convert everything to "struct proc_ops"

2020-02-04T03:05:26+00:00

The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in
seq_file.h.

Conversion rule is:

	llseek		=> proc_lseek
	unlocked_ioctl	=> proc_ioctl

	xxx		=> proc_xxx

	delete ".owner = THIS_MODULE" line

[akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c]
[sfr@canb.auug.org.au: fix kernel/sched/psi.c]
  Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au
Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2
Signed-off-by: Alexey Dobriyan 
Signed-off-by: Stephen Rothwell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

md/raid1: use bucket based mechanism for IO serialization

2020-01-13T19:44:10+00:00

Since raid1 had already used bucket based mechanism to reduce
the conflict between write IO and resync IO, it is possible to
speed up performance for io serialization with refer to the
same mechanism.

To align with the barrier bucket mechanism, we created arrays
(with the same number of BARRIER_BUCKETS_NR) for spinlock, rb
tree and waitqueue. Then we can reduce lock competition with
multiple spinlocks, boost search performance with multiple rb
trees and also reduce thundering herd problem with multiple
waitqueues.

Signed-off-by: Guoqing Jiang 
Signed-off-by: Song Liu