linux-stable.git/drivers/block/nbd.c, branch v4.9

nbd: Fix error handling

2016-11-06T21:14:59+00:00

'blk_mq_alloc_request()' returns an error pointer in case of error, not
NULL. So test it with IS_ERR.

Fixes: 	fd8383fd88a2 ("nbd: convert to blkmq")

Signed-off-by: Christophe JAILLET 
Signed-off-by: Jens Axboe

nbd: fix incorrect unlock of nbd->sock_lock in sock_shutdown

2016-10-24T19:18:14+00:00

Commit 0eadf37afc250 ("nbd: allow block mq to deal with timeouts")
changed normal usage of nbd->sock_lock to use spin_lock/spin_unlock
rather than the *_irq variants, but it missed this unlock in an
error path.

Found by Coverity, CID 1373871.

Signed-off-by: John W. Linville 
Cc: Josef Bacik 
Cc: Jens Axboe 
Cc: Markus Pargmann 
Fixes: 0eadf37afc250 ("nbd: allow block mq to deal with timeouts")
Signed-off-by: Jens Axboe

Merge branch 'for-4.9/block-irq' of git://git.kernel.dk/linux-block

2016-10-10T00:29:33+00:00

Pull blk-mq irq/cpu mapping updates from Jens Axboe:
 "This is the block-irq topic branch for 4.9-rc. It's mostly from
  Christoph, and it allows drivers to specify their own mappings, and
  more importantly, to share the blk-mq mappings with the IRQ affinity
  mappings. It's a good step towards making this work better out of the
  box"

* 'for-4.9/block-irq' of git://git.kernel.dk/linux-block:
  blk_mq: linux/blk-mq.h does not include all the headers it depends on
  blk-mq: kill unused blk_mq_create_mq_map()
  blk-mq: get rid of the cpumask in struct blk_mq_tags
  nvme: remove the post_scan callout
  nvme: switch to use pci_alloc_irq_vectors
  blk-mq: provide a default queue mapping for PCI device
  blk-mq: allow the driver to pass in a queue mapping
  blk-mq: remove ->map_queue
  blk-mq: only allocate a single mq_map per tag_set
  blk-mq: don't redistribute hardware queues on a CPU hotplug event

nbd: use BLK_MQ_F_BLOCKING

2016-09-23T17:46:42+00:00

We take a mutex when sending commands and send stuff over the network, we need
to have queue_rq called asynchronously.

Signed-off-by: Josef Bacik 
Fixes: fd8383fd88a2 ("nbd: convert to blkmq")
Signed-off-by: Jens Axboe

nbd: allow block mq to deal with timeouts

2016-09-08T20:01:37+00:00

Instead of rolling our own timer, just utilize the blk mq req timeout and do the
disconnect if any of our commands timeout.

Signed-off-by: Josef Bacik 
Signed-off-by: Jens Axboe

nbd: use flags instead of bool

2016-09-08T20:01:35+00:00

In preparation for some future changes, change a few of the state bools over to
normal bits to set/clear properly.

Signed-off-by: Josef Bacik 
Signed-off-by: Jens Axboe

nbd: don't shutdown sock with irq's disabled

2016-09-08T20:01:34+00:00

We hit a warning when shutting down the nbd connection because we have irq's
disabled.  We don't really need to do the shutdown under the lock, just clear
the nbd->sock.  So do the shutdown outside of the irq.  This gets rid of the
warning.

Signed-off-by: Josef Bacik 
Signed-off-by: Jens Axboe

nbd: convert to blkmq

2016-09-08T20:01:32+00:00

This moves NBD over to using blkmq, which allows us to get rid of the NBD
wide queue lock and the async submit kthread.  We will start with 1 hw
queue for now, but I plan to add multiple tcp connection support in the
future and we'll fix how we set the hwqueue's.

Signed-off-by: Josef Bacik 
Signed-off-by: Jens Axboe

nbd: fix race in ioctl

2016-08-04T20:19:16+00:00

Quentin ran into this bug:

WARNING: CPU: 64 PID: 10085 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x65/0x80
sysfs: cannot create duplicate filename '/devices/virtual/block/nbd3/pid'
Modules linked in: nbd
CPU: 64 PID: 10085 Comm: qemu-nbd Tainted: G      D         4.6.0+ #7
 0000000000000000 ffff8820330bba68 ffffffff814b8791 ffff8820330bbac8
 0000000000000000 ffff8820330bbab8 ffffffff810d04ab ffff8820330bbaa8
 0000001f00000296 0000000000017681 ffff8810380bf000 ffffffffa0001790
Call Trace:
 [] dump_stack+0x4d/0x6c
 [] __warn+0xdb/0x100
 [] warn_slowpath_fmt+0x44/0x50
 [] sysfs_warn_dup+0x65/0x80
 [] sysfs_add_file_mode_ns+0x172/0x180
 [] sysfs_create_file_ns+0x25/0x30
 [] device_create_file+0x36/0x90
 [] __nbd_ioctl+0x32d/0x9b0 [nbd]
 [] ? find_next_bit+0x18/0x20
 [] ? select_idle_sibling+0xe9/0x120
 [] ? __enqueue_entity+0x67/0x70
 [] ? enqueue_task_fair+0x630/0xe20
 [] ? resched_curr+0x36/0x70
 [] ? check_preempt_curr+0x78/0x90
 [] ? ttwu_do_wakeup+0x12/0x80
 [] ? ttwu_do_activate.constprop.86+0x61/0x70
 [] ? try_to_wake_up+0x185/0x2d0
 [] ? default_wake_function+0xd/0x10
 [] ? autoremove_wake_function+0x11/0x40
 [] nbd_ioctl+0x67/0x94 [nbd]
 [] blkdev_ioctl+0x14d/0x940
 [] ? put_pipe_info+0x22/0x60
 [] block_ioctl+0x3c/0x40
 [] do_vfs_ioctl+0x8d/0x5e0
 [] ? ____fput+0x9/0x10
 [] ? task_work_run+0x72/0x90
 [] SyS_ioctl+0x47/0x80
 [] entry_SYSCALL_64_fastpath+0x17/0x93
---[ end trace 7899b295e4f850c8 ]---

It seems fairly obvious that device_create_file() is not being protected
from being run concurrently on the same nbd.

Quentin found the following relevant commits:

1a2ad21 nbd: add locking to nbd_ioctl
90b8f28 [PATCH] end of methods switch: remove the old ones
d4430d6 [PATCH] beginning of methods conversion
08f8585 [PATCH] move block_device_operations to blkdev.h

It would seem that the race was introduced in the process of moving nbd
from BKL to unlocked ioctls.

By setting nbd->task_recv while the mutex is held, we can prevent other
processes from running concurrently (since nbd->task_recv is also checked
while the mutex is held).

Reported-and-tested-by: Quentin Casasnovas 
Cc: Markus Pargmann 
Cc: Paul Clements 
Cc: Pavel Machek 
Cc: Jens Axboe 
Cc: Al Viro 
Signed-off-by: Vegard Nossum 
Signed-off-by: Jens Axboe

Merge branch 'for-4.8/core' of git://git.kernel.dk/linux-block

2016-07-26T22:03:07+00:00

Pull core block updates from Jens Axboe:

   - the big change is the cleanup from Mike Christie, cleaning up our
     uses of command types and modified flags.  This is what will throw
     some merge conflicts

   - regression fix for the above for btrfs, from Vincent

   - following up to the above, better packing of struct request from
     Christoph

   - a 2038 fix for blktrace from Arnd

   - a few trivial/spelling fixes from Bart Van Assche

   - a front merge check fix from Damien, which could cause issues on
     SMR drives

   - Atari partition fix from Gabriel

   - convert cfq to highres timers, since jiffies isn't granular enough
     for some devices these days.  From Jan and Jeff

   - CFQ priority boost fix idle classes, from me

   - cleanup series from Ming, improving our bio/bvec iteration

   - a direct issue fix for blk-mq from Omar

   - fix for plug merging not involving the IO scheduler, like we do for
     other types of merges.  From Tahsin

   - expose DAX type internally and through sysfs.  From Toshi and Yigal

* 'for-4.8/core' of git://git.kernel.dk/linux-block: (76 commits)
  block: Fix front merge check
  block: do not merge requests without consulting with io scheduler
  block: Fix spelling in a source code comment
  block: expose QUEUE_FLAG_DAX in sysfs
  block: add QUEUE_FLAG_DAX for devices to advertise their DAX support
  Btrfs: fix comparison in __btrfs_map_block()
  block: atari: Return early for unsupported sector size
  Doc: block: Fix a typo in queue-sysfs.txt
  cfq-iosched: Charge at least 1 jiffie instead of 1 ns
  cfq-iosched: Fix regression in bonnie++ rewrite performance
  cfq-iosched: Convert slice_resid from u64 to s64
  block: Convert fifo_time from ulong to u64
  blktrace: avoid using timespec
  block/blk-cgroup.c: Declare local symbols static
  block/bio-integrity.c: Add #include "blk.h"
  block/partition-generic.c: Remove a set-but-not-used variable
  block: bio: kill BIO_MAX_SIZE
  cfq-iosched: temporarily boost queue priority for idle classes
  block: drbd: avoid to use BIO_MAX_SIZE
  block: bio: remove BIO_MAX_SECTORS
  ...