linux-toradex.git/drivers/block/xen-blkback, branch v3.18-rc5

Merge branch 'for-3.18/drivers' of git://git.kernel.dk/linux-block

2014-10-18T19:12:45+00:00

Pull block layer driver update from Jens Axboe:
 "This is the block driver pull request for 3.18.  Not a lot in there
  this round, and nothing earth shattering.

   - A round of drbd fixes from the linbit team, and an improvement in
     asender performance.

   - Removal of deprecated (and unused) IRQF_DISABLED flag in rsxx and
     hd from Michael Opdenacker.

   - Disable entropy collection from flash devices by default, from Mike
     Snitzer.

   - A small collection of xen blkfront/back fixes from Roger Pau Monné
     and Vitaly Kuznetsov"

* 'for-3.18/drivers' of git://git.kernel.dk/linux-block:
  block: disable entropy contributions for nonrot devices
  xen, blkfront: factor out flush-related checks from do_blkif_request()
  xen-blkback: fix leak on grant map error path
  xen/blkback: unmap all persistent grants when frontend gets disconnected
  rsxx: Remove deprecated IRQF_DISABLED
  block: hd: remove deprecated IRQF_DISABLED
  drbd: use RB_DECLARE_CALLBACKS() to define augment callbacks
  drbd: compute the end before rb_insert_augmented()
  drbd: Add missing newline in resync progress display in /proc/drbd
  drbd: reduce lock contention in drbd_worker
  drbd: Improve asender performance
  drbd: Get rid of the WORK_PENDING macro
  drbd: Get rid of the __no_warn and __cond_lock macros
  drbd: Avoid inconsistent locking warning
  drbd: Remove superfluous newline from "resync_extents" debugfs entry.
  drbd: Use consistent names for all the bi_end_io callbacks
  drbd: Use better variable names

xen: remove DEFINE_XENBUS_DRIVER() macro

2014-10-06T09:27:57+00:00

The DEFINE_XENBUS_DRIVER() macro looks a bit weird and causes sparse
errors.

Replace the uses with standard structure definitions instead.  This is
similar to pci and usb device registration.

Signed-off-by: David Vrabel

xen-blkback: fix leak on grant map error path

2014-10-01T20:32:31+00:00

Fix leaking a page when a grant mapping has failed.

CC: stable@vger.kernel.org
Signed-off-by: Roger Pau Monné 
Reported-and-Tested-by: Tao Chen 
Signed-off-by: Konrad Rzeszutek Wilk

xen/blkback: unmap all persistent grants when frontend gets disconnected

2014-10-01T20:32:23+00:00

blkback does not unmap persistent grants when frontend goes to Closed
state (e.g. when blkfront module is being removed). This leads to the
following in guest's dmesg:

[  343.243825] xen:grant_table: WARNING: g.e. 0x445 still in use!
[  343.243825] xen:grant_table: WARNING: g.e. 0x42a still in use!
...

When load module -> use device -> unload module sequence is performed multiple times
it is possible to hit BUG() condition in blkfront module:

[  343.243825] kernel BUG at drivers/block/xen-blkfront.c:954!
[  343.243825] invalid opcode: 0000 [#1] SMP
[  343.243825] Modules linked in: xen_blkfront(-) ata_generic pata_acpi [last unloaded: xen_blkfront]
...
[  343.243825] Call Trace:
[  343.243825]  [] ? unregister_xenbus_watch+0x16f/0x1e0
[  343.243825]  [] blkfront_remove+0x3f/0x140 [xen_blkfront]
...
[  343.243825] RIP  [] blkif_free+0x34e/0x360 [xen_blkfront]
[  343.243825]  RSP 

We don't need to keep these grants if we're disconnecting as frontend might already
forgot about them. Solve the issue by moving xen_blkbk_free_caches() call from
xen_blkif_free() to xen_blkif_disconnect().

Now we can see the following:
[  928.590893] xen:grant_table: WARNING: g.e. 0x587 still in use!
[  928.591861] xen:grant_table: WARNING: g.e. 0x372 still in use!
...
[  929.592146] xen:grant_table: freeing g.e. 0x587
[  929.597174] xen:grant_table: freeing g.e. 0x372
...

Backend does not keep persistent grants any more, reconnect works fine.

CC: stable@vger.kernel.org
Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: Konrad Rzeszutek Wilk

xen-blkback: defer freeing blkif to avoid blocking xenwatch

2014-05-28T18:17:32+00:00

Currently xenwatch blocks in VBD disconnect, waiting for all pending I/O
requests to finish. If the VBD is attached to a hot-swappable disk, then
xenwatch can hang for a long period of time, stalling other watches.

 INFO: task xenwatch:39 blocked for more than 120 seconds.
 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
 ffff880057f01bd0 0000000000000246 ffff880057f01ac0 ffffffff810b0782
 ffff880057f01ad0 00000000000131c0 0000000000000004 ffff880057edb040
 ffff8800344c6080 0000000000000000 ffff880058c00ba0 ffff880057edb040
 Call Trace:
 [] ? irq_to_desc+0x12/0x20
 [] ? list_del+0x11/0x40
 [] ? wait_for_common+0x60/0x160
 [] ? _raw_spin_lock_irqsave+0x2f/0x50
 [] ? _raw_spin_unlock_irqrestore+0x19/0x20
 [] schedule+0x3a/0x60
 [] xen_blkif_disconnect+0x8a/0x100 [xen_blkback]
 [] ? wake_up_bit+0x40/0x40
 [] xen_blkbk_remove+0xae/0x1e0 [xen_blkback]
 [] xenbus_dev_remove+0x44/0x90
 [] __device_release_driver+0x77/0xd0
 [] device_release_driver+0x28/0x40
 [] bus_remove_device+0x78/0xe0
 [] device_del+0x12f/0x1a0
 [] device_unregister+0x1d/0x60
 [] frontend_changed+0xa6/0x4d0 [xen_blkback]
 [] ? frontend_changed+0x192/0x650 [xen_netback]
 [] ? cmp_dev+0x60/0x60
 [] ? bus_for_each_dev+0x94/0xa0
 [] xenbus_otherend_changed+0xbe/0x120
 [] frontend_changed+0xb/0x10
 [] xenwatch_thread+0xf2/0x130
 [] ? wake_up_bit+0x40/0x40
 [] ? xenbus_directory+0x80/0x80
 [] kthread+0x96/0xa0
 [] kernel_thread_helper+0x4/0x10
 [] ? int_ret_from_sys_call+0x7/0x1b
 [] ? retint_restore_args+0x5/0x6
 [] ? gs_change+0x13/0x13

With this patch, when there is still pending I/O, the actual disconnect
is done by the last reference holder (last pending I/O request). In this
case, xenwatch doesn't block indefinitely.

Signed-off-by: Valentin Priescu 
Reviewed-by: Steven Kady 
Reviewed-by: Steven Noonan 
Reviewed-by: David Vrabel 
Signed-off-by: Konrad Rzeszutek Wilk

xen/blkback: disable discard feature if requested by toolstack

2014-05-28T18:17:28+00:00

Newer toolstacks may provide a boolean property "discard-enable" in the
backend node. Its purpose is to disable discard for file backed storage
to avoid fragmentation. Recognize this setting also for physical
storage.  If that property exists and is false, do not advertise
"feature-discard" to the frontend.

Signed-off-by: Olaf Hering 
Signed-off-by: Konrad Rzeszutek Wilk

xen-blkback: init persistent_purge_work work_struct

2014-02-12T03:34:03+00:00

Initialize persistent_purge_work work_struct on xen_blkif_alloc (and
remove the previous initialization done in purge_persistent_gnt). This
prevents flush_work from complaining even if purge_persistent_gnt has
not been used.

Signed-off-by: Roger Pau Monné 
Reviewed-by: David Vrabel 
Tested-by: Sander Eikelenboom 
Signed-off-by: Jens Axboe

Merge branch 'stable/for-jens-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip into for-linus

2014-02-10T19:52:34+00:00

Konrad writes:

Please git pull the following branch:

 git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git stable/for-jens-3.14

which is based off v3.13-rc6. If you would like me to rebase it on
a different branch/tag I would be more than happy to do so.

The patches are all bug-fixes and hopefully can go in 3.14.

They deal with xen-blkback shutdown and cause memory leaks
as well as shutdown races. They should go to stable tree and if you
are OK with I will ask them to backport those fixes.

There is also a fix to xen-blkfront to deal with unexpected state
transition. And lastly a fix to the header where it was using the
__aligned__ unnecessarily.

xen-blkif: drop struct blkif_request_segment_aligned

2014-02-07T18:03:53+00:00

This was wrongly introduced in commit 402b27f9, the only difference
between blkif_request_segment_aligned and blkif_request_segment is
that the former has a named padding, while both share the same
memory layout.

Also correct a few minor glitches in the description, including for it
to no longer assume PAGE_SIZE == 4096.

Signed-off-by: Roger Pau Monné 
[Description fix by Jan Beulich]
Signed-off-by: Jan Beulich 
Reported-by: Jan Beulich 
Cc: Konrad Rzeszutek Wilk 
Cc: David Vrabel 
Cc: Boris Ostrovsky 
Tested-by: Matt Rushton 
Cc: Matt Wilson 
Signed-off-by: Konrad Rzeszutek Wilk

xen-blkback: fix shutdown race

2014-02-07T17:59:30+00:00

Introduce a new variable to keep track of the number of in-flight
requests. We need to make sure that when xen_blkif_put is called the
request has already been freed and we can safely free xen_blkif, which
was not the case before.

Signed-off-by: Roger Pau Monné 
Cc: Konrad Rzeszutek Wilk 
Cc: David Vrabel 
Reviewed-by: Boris Ostrovsky 
Tested-by: Matt Rushton 
Reviewed-by: Matt Rushton 
Cc: Matt Wilson 
Cc: Ian Campbell 
Signed-off-by: Konrad Rzeszutek Wilk