linux-toradex.git/drivers/block/virtio_blk.c, branch v3.2.59 Linux kernel for Apalis and Colibri modules virtio-blk: Call revalidate_disk() upon online disk resize 2013-06-29T03:06:34+00:00 Vivek Goyal vgoyal@redhat.com 2012-03-29T08:09:44+00:00 c32f3410245d666c5bea0e3b6e1e8aad6091b19f commit e9986f303dc0f285401de28cf96f42f4dd23a4a1 upstream. If a virtio disk is open in guest and a disk resize operation is done, (virsh blockresize), new size is not visible to tools like "fdisk -l". This seems to be happening as we update only part->nr_sects and not bdev->bd_inode size. Call revalidate_disk() which should take care of it. I tested growing disk size of already open disk and it works for me. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit e9986f303dc0f285401de28cf96f42f4dd23a4a1 upstream.

If a virtio disk is open in guest and a disk resize operation is done,
(virsh blockresize), new size is not visible to tools like "fdisk -l".
This seems to be happening as we update only part->nr_sects and not
bdev->bd_inode size.

Call revalidate_disk() which should take care of it. I tested growing disk
size of already open disk and it works for me.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
virtio-blk: Don't free ida when disk is in use 2013-02-06T04:33:19+00:00 Alexander Graf agraf@suse.de 2013-01-02T05:07:17+00:00 63dddb4936fa86057e7f94a0bd10cb8ac25bc7f3 commit f4953fe6c4aeada2d5cafd78aa97587a46d2d8f9 upstream. When a file system is mounted on a virtio-blk disk, we then remove it and then reattach it, the reattached disk gets the same disk name and ids as the hot removed one. This leads to very nasty effects - mostly rendering the newly attached device completely unusable. Trying what happens when I do the same thing with a USB device, I saw that the sd node simply doesn't get free'd when a device gets forcefully removed. Imitate the same behavior for vd devices. This way broken vd devices simply are never free'd and newly attached ones keep working just fine. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit f4953fe6c4aeada2d5cafd78aa97587a46d2d8f9 upstream.

When a file system is mounted on a virtio-blk disk, we then remove it
and then reattach it, the reattached disk gets the same disk name and
ids as the hot removed one.

This leads to very nasty effects - mostly rendering the newly attached
device completely unusable.

Trying what happens when I do the same thing with a USB device, I saw
that the sd node simply doesn't get free'd when a device gets forcefully
removed.

Imitate the same behavior for vd devices. This way broken vd devices
simply are never free'd and newly attached ones keep working just fine.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
virtio-blk: Reset device after blk_cleanup_queue() 2012-09-12T02:37:33+00:00 Asias He asias@redhat.com 2012-05-25T02:34:48+00:00 95964784565aeac65d1c03fc7b2443f8f7102340 commit 483001c765af6892b3fc3726576cb42f17d1d6b5 upstream. blk_cleanup_queue() will call blk_drian_queue() to drain all the requests before queue DEAD marking. If we reset the device before blk_cleanup_queue() the drain would fail. 1) if the queue is stopped in do_virtblk_request() because device is full, the q->request_fn() will not be called. blk_drain_queue() { while(true) { ... if (!list_empty(&q->queue_head)) __blk_run_queue(q) { if (queue is not stoped) q->request_fn() } ... } } Do no reset the device before blk_cleanup_queue() gives the chance to start the queue in interrupt handler blk_done(). 2) In commit b79d866c8b7014a51f611a64c40546109beaf24a, We abort requests dispatched to driver before blk_cleanup_queue(). There is a race if requests are dispatched to driver after the abort and before the queue DEAD mark. To fix this, instead of aborting the requests explicitly, we can just reset the device after after blk_cleanup_queue so that the device can complete all the requests before queue DEAD marking in the drain process. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: virtualization@lists.linux-foundation.org Cc: kvm@vger.kernel.org Signed-off-by: Asias He <asias@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 483001c765af6892b3fc3726576cb42f17d1d6b5 upstream.

blk_cleanup_queue() will call blk_drian_queue() to drain all the
requests before queue DEAD marking. If we reset the device before
blk_cleanup_queue() the drain would fail.

1) if the queue is stopped in do_virtblk_request() because device is
full, the q->request_fn() will not be called.

blk_drain_queue() {
   while(true) {
      ...
      if (!list_empty(&q->queue_head))
        __blk_run_queue(q) {
	    if (queue is not stoped)
		q->request_fn()
	}
      ...
   }
}

Do no reset the device before blk_cleanup_queue() gives the chance to
start the queue in interrupt handler blk_done().

2) In commit b79d866c8b7014a51f611a64c40546109beaf24a, We abort requests
dispatched to driver before blk_cleanup_queue(). There is a race if
requests are dispatched to driver after the abort and before the queue
DEAD mark. To fix this, instead of aborting the requests explicitly, we
can just reset the device after after blk_cleanup_queue so that the
device can complete all the requests before queue DEAD marking in the
drain process.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: virtualization@lists.linux-foundation.org
Cc: kvm@vger.kernel.org
Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
virtio-blk: Call del_gendisk() before disable guest kick 2012-09-12T02:37:33+00:00 Asias He asias@redhat.com 2012-05-25T02:34:47+00:00 88963fd6c66bf065c6e9c36f1f5de4dff30624a1 commit 02e2b124943648fba0a2ccee5c3656a5653e0151 upstream. del_gendisk() might not return due to failing to remove the /sys/block/vda/serial sysfs entry when another thread (udev) is trying to read it. virtblk_remove() vdev->config->reset() : guest will not kick us through interrupt del_gendisk() device_del() kobject_del(): got stuck, sysfs entry ref count non zero sysfs_open_file(): user space process read /sys/block/vda/serial sysfs_get_active() : got sysfs entry ref count dev_attr_show() virtblk_serial_show() blk_execute_rq() : got stuck, interrupt is disabled request cannot be finished This patch fixes it by calling del_gendisk() before we disable guest's interrupt so that the request sent in virtblk_serial_show() will be finished and del_gendisk() will success. This fixes another race in hot-unplug process. It is save to call del_gendisk(vblk->disk) before flush_work(&vblk->config_work) which might access vblk->disk, because vblk->disk is not freed until put_disk(vblk->disk). Cc: virtualization@lists.linux-foundation.org Cc: kvm@vger.kernel.org Signed-off-by: Asias He <asias@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 02e2b124943648fba0a2ccee5c3656a5653e0151 upstream.

del_gendisk() might not return due to failing to remove the
/sys/block/vda/serial sysfs entry when another thread (udev) is
trying to read it.

virtblk_remove()
  vdev->config->reset() : guest will not kick us through interrupt
    del_gendisk()
      device_del()
        kobject_del(): got stuck, sysfs entry ref count non zero

sysfs_open_file(): user space process read /sys/block/vda/serial
   sysfs_get_active() : got sysfs entry ref count
      dev_attr_show()
        virtblk_serial_show()
           blk_execute_rq() : got stuck, interrupt is disabled
                              request cannot be finished

This patch fixes it by calling del_gendisk() before we disable guest's
interrupt so that the request sent in virtblk_serial_show() will be
finished and del_gendisk() will success.

This fixes another race in hot-unplug process.

It is save to call del_gendisk(vblk->disk) before
flush_work(&vblk->config_work) which might access vblk->disk, because
vblk->disk is not freed until put_disk(vblk->disk).

Cc: virtualization@lists.linux-foundation.org
Cc: kvm@vger.kernel.org
Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
virtio-blk: Fix hot-unplug race in remove method 2012-09-12T02:37:32+00:00 Asias He asias@redhat.com 2012-05-04T12:22:04+00:00 e5000b33460e5008a3a189dc2107d274d8096eff commit b79d866c8b7014a51f611a64c40546109beaf24a upstream. If we reset the virtio-blk device before the requests already dispatched to the virtio-blk driver from the block layer are finised, we will stuck in blk_cleanup_queue() and the remove will fail. blk_cleanup_queue() calls blk_drain_queue() to drain all requests queued before DEAD marking. However it will never success if the device is already stopped. We'll have q->in_flight[] > 0, so the drain will not finish. How to reproduce the race: 1. hot-plug a virtio-blk device 2. keep reading/writing the device in guest 3. hot-unplug while the device is busy serving I/O Test: ~1000 rounds of hot-plug/hot-unplug test passed with this patch. Changes in v3: - Drop blk_abort_queue and blk_abort_request - Use __blk_end_request_all to complete request dispatched to driver Changes in v2: - Drop req_in_flight - Use virtqueue_detach_unused_buf to get request dispatched to driver Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit b79d866c8b7014a51f611a64c40546109beaf24a upstream.

If we reset the virtio-blk device before the requests already dispatched
to the virtio-blk driver from the block layer are finised, we will stuck
in blk_cleanup_queue() and the remove will fail.

blk_cleanup_queue() calls blk_drain_queue() to drain all requests queued
before DEAD marking. However it will never success if the device is
already stopped. We'll have q->in_flight[] > 0, so the drain will not
finish.

How to reproduce the race:
1. hot-plug a virtio-blk device
2. keep reading/writing the device in guest
3. hot-unplug while the device is busy serving I/O

Test:
~1000 rounds of hot-plug/hot-unplug test passed with this patch.

Changes in v3:
- Drop blk_abort_queue and blk_abort_request
- Use __blk_end_request_all to complete request dispatched to driver

Changes in v2:
- Drop req_in_flight
- Use virtqueue_detach_unused_buf to get request dispatched to driver

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
virtio_blk: Drop unused request tracking list 2012-09-12T02:37:31+00:00 Asias He asias@redhat.com 2012-03-30T03:24:10+00:00 788c8de383e3c59df49126f95343eed0cf1733ea commit f65ca1dc6a8c81c6bd72297d4399ec5f4c1f3a01 upstream. Benchmark shows small performance improvement on fusion io device. Before: seq-read : io=1,024MB, bw=19,982KB/s, iops=39,964, runt= 52475msec seq-write: io=1,024MB, bw=20,321KB/s, iops=40,641, runt= 51601msec rnd-read : io=1,024MB, bw=15,404KB/s, iops=30,808, runt= 68070msec rnd-write: io=1,024MB, bw=14,776KB/s, iops=29,552, runt= 70963msec After: seq-read : io=1,024MB, bw=20,343KB/s, iops=40,685, runt= 51546msec seq-write: io=1,024MB, bw=20,803KB/s, iops=41,606, runt= 50404msec rnd-read : io=1,024MB, bw=16,221KB/s, iops=32,442, runt= 64642msec rnd-write: io=1,024MB, bw=15,199KB/s, iops=30,397, runt= 68991msec Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit f65ca1dc6a8c81c6bd72297d4399ec5f4c1f3a01 upstream.

Benchmark shows small performance improvement on fusion io device.

Before:
  seq-read : io=1,024MB, bw=19,982KB/s, iops=39,964, runt= 52475msec
  seq-write: io=1,024MB, bw=20,321KB/s, iops=40,641, runt= 51601msec
  rnd-read : io=1,024MB, bw=15,404KB/s, iops=30,808, runt= 68070msec
  rnd-write: io=1,024MB, bw=14,776KB/s, iops=29,552, runt= 70963msec

After:
  seq-read : io=1,024MB, bw=20,343KB/s, iops=40,685, runt= 51546msec
  seq-write: io=1,024MB, bw=20,803KB/s, iops=41,606, runt= 50404msec
  rnd-read : io=1,024MB, bw=16,221KB/s, iops=32,442, runt= 64642msec
  rnd-write: io=1,024MB, bw=15,199KB/s, iops=30,397, runt= 68991msec

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
virtio_blk: fix config handler race 2012-09-12T02:37:31+00:00 Michael S. Tsirkin mst@redhat.com 2012-01-12T05:14:44+00:00 0984c4c423da091cf8221e74b030c116d865dacf commit 4678d6f970c2f7c0cbfefc0cc666432d153b321b upstream. Fix a theoretical race related to config work handler: a config interrupt might happen after we flush config work but before we reset the device. It will then cause the config work to run during or after reset. Two problems with this: - if this runs after device is gone we will get use after free - access of config while reset is in progress is racy (as layout is changing). As a solution 1. flush after reset when we know there will be no more interrupts 2. add a flag to disable config access before reset Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 4678d6f970c2f7c0cbfefc0cc666432d153b321b upstream.

Fix a theoretical race related to config work
handler: a config interrupt might happen
after we flush config work but before we
reset the device. It will then cause the
config work to run during or after reset.

Two problems with this:
- if this runs after device is gone we will get use after free
- access of config while reset is in progress is racy
(as layout is changing).

As a solution
1. flush after reset when we know there will be no more interrupts
2. add a flag to disable config access before reset

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
virtio-blk: Use block layer provided spinlock 2012-08-09T23:24:58+00:00 Asias He asias@redhat.com 2012-05-25T08:03:27+00:00 e551857183b52b1af787e35b25a4e556fa0c0c75 commit 2c95a3290919541b846bee3e0fbaa75860929f53 upstream. Block layer will allocate a spinlock for the queue if the driver does not provide one in blk_init_queue(). The reason to use the internal spinlock is that blk_cleanup_queue() will switch to use the internal spinlock in the cleanup code path. if (q->queue_lock != &q->__queue_lock) q->queue_lock = &q->__queue_lock; However, processes which are in D state might have taken the driver provided spinlock, when the processes wake up, they would release the block provided spinlock. ===================================== [ BUG: bad unlock balance detected! ] 3.4.0-rc7+ #238 Not tainted ------------------------------------- fio/3587 is trying to release lock (&(&q->__queue_lock)->rlock) at: [<ffffffff813274d2>] blk_queue_bio+0x2a2/0x380 but there are no more locks to release! other info that might help us debug this: 1 lock held by fio/3587: #0: (&(&vblk->lock)->rlock){......}, at: [<ffffffff8132661a>] get_request_wait+0x19a/0x250 Other drivers use block layer provided spinlock as well, e.g. SCSI. Switching to the block layer provided spinlock saves a bit of memory and does not increase lock contention. Performance test shows no real difference is observed before and after this patch. Changes in v2: Improve commit log as Michael suggested. Cc: virtualization@lists.linux-foundation.org Cc: kvm@vger.kernel.org Signed-off-by: Asias He <asias@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 2c95a3290919541b846bee3e0fbaa75860929f53 upstream.

Block layer will allocate a spinlock for the queue if the driver does
not provide one in blk_init_queue().

The reason to use the internal spinlock is that blk_cleanup_queue() will
switch to use the internal spinlock in the cleanup code path.

        if (q->queue_lock != &q->__queue_lock)
                q->queue_lock = &q->__queue_lock;

However, processes which are in D state might have taken the driver
provided spinlock, when the processes wake up, they would release the
block provided spinlock.

=====================================
[ BUG: bad unlock balance detected! ]
3.4.0-rc7+ #238 Not tainted
-------------------------------------
fio/3587 is trying to release lock (&(&q->__queue_lock)->rlock) at:
[<ffffffff813274d2>] blk_queue_bio+0x2a2/0x380
but there are no more locks to release!

other info that might help us debug this:
1 lock held by fio/3587:
 #0:  (&(&vblk->lock)->rlock){......}, at:
[<ffffffff8132661a>] get_request_wait+0x19a/0x250

Other drivers use block layer provided spinlock as well, e.g. SCSI.

Switching to the block layer provided spinlock saves a bit of memory and
does not increase lock contention. Performance test shows no real
difference is observed before and after this patch.

Changes in v2: Improve commit log as Michael suggested.

Cc: virtualization@lists.linux-foundation.org
Cc: kvm@vger.kernel.org
Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
block: add and use scsi_blk_cmd_ioctl 2012-01-26T00:13:42+00:00 Paolo Bonzini pbonzini@redhat.com 2012-01-12T15:01:27+00:00 36a7ce632fb11cce578b7fdf4b4bbc8fbb99987a commit 577ebb374c78314ac4617242f509e2f5e7156649 upstream. Introduce a wrapper around scsi_cmd_ioctl that takes a block device. The function will then be enhanced to detect partition block devices and, in that case, subject the ioctls to whitelisting. Cc: linux-scsi@vger.kernel.org Cc: Jens Axboe <axboe@kernel.dk> Cc: James Bottomley <JBottomley@parallels.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> 
commit 577ebb374c78314ac4617242f509e2f5e7156649 upstream.

Introduce a wrapper around scsi_cmd_ioctl that takes a block device.

The function will then be enhanced to detect partition block devices
and, in that case, subject the ioctls to whitelisting.

Cc: linux-scsi@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: James Bottomley <JBottomley@parallels.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-07T03:44:47+00:00 Linus Torvalds torvalds@linux-foundation.org 2011-11-07T03:44:47+00:00 32aaeffbd4a7457bf2f7448b33b5946ff2a960eb * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include <linux/module.h> acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include <linux/module.h> net: sch_generic remove redundant use of <linux/module.h> net: inet_timewait_sock doesnt need <linux/module.h> ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h 
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
  Revert "tracing: Include module.h in define_trace.h"
  irq: don't put module.h into irq.h for tracking irqgen modules.
  bluetooth: macroize two small inlines to avoid module.h
  ip_vs.h: fix implicit use of module_get/module_put from module.h
  nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
  include: replace linux/module.h with "struct module" wherever possible
  include: convert various register fcns to macros to avoid include chaining
  crypto.h: remove unused crypto_tfm_alg_modname() inline
  uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
  pm_runtime.h: explicitly requires notifier.h
  linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
  miscdevice.h: fix up implicit use of lists and types
  stop_machine.h: fix implicit use of smp.h for smp_processor_id
  of: fix implicit use of errno.h in include/linux/of.h
  of_platform.h: delete needless include <linux/module.h>
  acpi: remove module.h include from platform/aclinux.h
  miscdevice.h: delete unnecessary inclusion of module.h
  device_cgroup.h: delete needless include <linux/module.h>
  net: sch_generic remove redundant use of <linux/module.h>
  net: inet_timewait_sock doesnt need <linux/module.h>
  ...

Fix up trivial conflicts (other header files, and  removal of the ab3550 mfd driver) in
 - drivers/media/dvb/frontends/dibx000_common.c
 - drivers/media/video/{mt9m111.c,ov6650.c}
 - drivers/mfd/ab3550-core.c
 - include/linux/dmaengine.h