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7 years agodm mpath: merge do_end_io into multipath_end_io
Christoph Hellwig [Wed, 26 Apr 2017 07:40:36 +0000 (09:40 +0200)]
dm mpath: merge do_end_io into multipath_end_io

This simplifies the I/O completion path a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agoMerge branch 'dm-4.12' into dm-4.12-post-merge
Mike Snitzer [Mon, 1 May 2017 22:18:04 +0000 (18:18 -0400)]
Merge branch 'dm-4.12' into dm-4.12-post-merge

7 years agodm bufio: check new buffer allocation watermark every 30 seconds
Mikulas Patocka [Sun, 30 Apr 2017 21:34:53 +0000 (17:34 -0400)]
dm bufio: check new buffer allocation watermark every 30 seconds

dm-bufio checks a watermark when it allocates a new buffer in
__bufio_new().  However, it doesn't check the watermark when the user
changes /sys/module/dm_bufio/parameters/max_cache_size_bytes.

This may result in a problem - if the watermark is high enough so that
all possible buffers are allocated and if the user lowers the value of
"max_cache_size_bytes", the watermark will never be checked against the
new value because no new buffer would be allocated.

To fix this, change __evict_old_buffers() so that it checks the
watermark.  __evict_old_buffers() is called every 30 seconds, so if the
user reduces "max_cache_size_bytes", dm-bufio will react to this change
within 30 seconds and decrease memory consumption.

Depends-on: 1b0fb5a5b2 ("dm bufio: avoid a possible ABBA deadlock")
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm bufio: avoid a possible ABBA deadlock
Mikulas Patocka [Sun, 30 Apr 2017 21:33:26 +0000 (17:33 -0400)]
dm bufio: avoid a possible ABBA deadlock

__get_memory_limit() tests if dm_bufio_cache_size changed and calls
__cache_size_refresh() if it did.  It takes dm_bufio_clients_lock while
it already holds the client lock.  However, lock ordering is violated
because in cleanup_old_buffers() dm_bufio_clients_lock is taken before
the client lock.

This results in a possible deadlock and lockdep engine warning.

Fix this deadlock by changing mutex_lock() to mutex_trylock().  If the
lock can't be taken, it will be re-checked next time when a new buffer
is allocated.

Also add "unlikely" to the if condition, so that the optimizer assumes
that the condition is false.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agoblock: hide badblocks attribute by default
Dan Williams [Thu, 27 Apr 2017 21:46:26 +0000 (14:46 -0700)]
block: hide badblocks attribute by default

Commit 99e6608c9e74 "block: Add badblock management for gendisks"
allowed for drivers like pmem and software-raid to advertise a list of
bad media areas. However, it inadvertently added a 'badblocks' to all
block devices. Lets clean this up by having the 'badblocks' attribute
not be visible when the driver has not populated a 'struct badblocks'
instance in the gendisk.

Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: unify hctx delay_work and run_work
Jens Axboe [Mon, 10 Apr 2017 15:54:56 +0000 (09:54 -0600)]
blk-mq: unify hctx delay_work and run_work

The only difference between ->run_work and ->delay_work, is that
the latter is used to defer running a queue. This is done by
marking the queue stopped, and scheduling ->delay_work to run
sometime in the future. While the queue is stopped, direct runs
or runs through ->run_work will not run the queue.

If we combine the handlers, then we need to handle two things:

1) If a delayed/stopped run is scheduled, then we should not run
   the queue before that has been completed.
2) If a queue is delayed/stopped, the handler needs to restart
   the queue. Normally a run of a queue with the stopped bit set
   would be a no-op.

Case 1 is handled by modifying a currently pending queue run
to the deadline set by the caller of blk_mq_delay_queue().
Subsequent attempts to queue a queue run will find the work
item already pending, and direct runs will see a stopped queue
as before.

Case 2 is handled by adding a new bit, BLK_MQ_S_START_ON_RUN,
that tells the work handler that it should clear a stopped
queue and run the handler.

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblock: add kblock_mod_delayed_work_on()
Jens Axboe [Mon, 10 Apr 2017 15:54:55 +0000 (09:54 -0600)]
block: add kblock_mod_delayed_work_on()

This modifies (or adds, if not currently pending) an existing
delayed work item.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: unify hctx delayed_run_work and run_work
Jens Axboe [Mon, 10 Apr 2017 15:54:54 +0000 (09:54 -0600)]
blk-mq: unify hctx delayed_run_work and run_work

They serve the exact same purpose. Get rid of the non-delayed
work variant, and just run it without delay for the normal case.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agonbd: fix use after free on module unload
Josef Bacik [Fri, 28 Apr 2017 13:49:19 +0000 (09:49 -0400)]
nbd: fix use after free on module unload

list_for_each_entry() isn't super safe if we're freeing the objects
while we traverse the list.  Also don't bother taking the extra
reference, the module refcounting stuff will save us from having anybody
messing with the device while we're trying to unload.

Reported-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoMAINTAINERS: bfq: Add Paolo as maintainer for the BFQ I/O scheduler
Ulf Hansson [Fri, 28 Apr 2017 10:10:36 +0000 (12:10 +0200)]
MAINTAINERS: bfq: Add Paolo as maintainer for the BFQ I/O scheduler

Seems like this was forgotten in the bfq-series from Paolo. Let's do it now
so people don't miss out involving Paolo for any future changes or when
reporting bugs.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agodm mpath: make it easier to detect unintended I/O request flushes
Bart Van Assche [Thu, 27 Apr 2017 17:11:26 +0000 (10:11 -0700)]
dm mpath: make it easier to detect unintended I/O request flushes

I/O errors triggered by multipathd incorrectly not enabling the no-flush
flag for DM_DEVICE_SUSPEND or DM_DEVICE_RESUME are hard to debug.  Add
more logging to make it easier to debug this.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm mpath: cleanup QUEUE_IF_NO_PATH bit manipulation by introducing assign_bit()
Bart Van Assche [Thu, 27 Apr 2017 17:11:25 +0000 (10:11 -0700)]
dm mpath: cleanup QUEUE_IF_NO_PATH bit manipulation by introducing assign_bit()

No functional change but makes the code easier to read.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm mpath: micro-optimize the hot path relative to MPATHF_QUEUE_IF_NO_PATH
Bart Van Assche [Thu, 27 Apr 2017 17:11:24 +0000 (10:11 -0700)]
dm mpath: micro-optimize the hot path relative to MPATHF_QUEUE_IF_NO_PATH

Instead of checking MPATHF_QUEUE_IF_NO_PATH,
MPATHF_SAVED_QUEUE_IF_NO_PATH and the no_flush flag to decide whether
or not to push back a request (or bio) if there are no paths available,
only clear MPATHF_QUEUE_IF_NO_PATH in queue_if_no_path() if no_flush has
not been set.  The result is that only a single bit has to be tested in
the hot path to decide whether or not a request must be pushed back and
also that m->lock does not have to be taken in the hot path.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm: introduce enum dm_queue_mode to cleanup related code
Bart Van Assche [Thu, 27 Apr 2017 17:11:23 +0000 (10:11 -0700)]
dm: introduce enum dm_queue_mode to cleanup related code

Introduce an enumeration type for the queue mode.  This patch does
not change any functionality but makes the DM code easier to read.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm mpath: verify __pg_init_all_paths locking assumptions at runtime
Bart Van Assche [Thu, 27 Apr 2017 17:11:22 +0000 (10:11 -0700)]
dm mpath: verify __pg_init_all_paths locking assumptions at runtime

Verify at runtime that __pg_init_all_paths() is called with
multipath.lock held if lockdep is enabled.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm: verify suspend_locking assumptions at runtime
Bart Van Assche [Thu, 27 Apr 2017 17:11:21 +0000 (10:11 -0700)]
dm: verify suspend_locking assumptions at runtime

Ensure that the assumptions about the caller holding suspend_lock
are checked at runtime if lockdep is enabled.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm block manager: remove an unused argument from dm_block_manager_create()
Bart Van Assche [Thu, 27 Apr 2017 17:11:20 +0000 (10:11 -0700)]
dm block manager: remove an unused argument from dm_block_manager_create()

The 'cache_size' argument of dm_block_manager_create() has never been
used.  Remove it along with the definitions of the constants passed as
the 'cache_size' argument.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm rq: check blk_mq_register_dev() return value in dm_mq_init_request_queue()
Bart Van Assche [Thu, 27 Apr 2017 17:11:19 +0000 (10:11 -0700)]
dm rq: check blk_mq_register_dev() return value in dm_mq_init_request_queue()

Otherwise the request-based DM blk-mq request_queue will be put into
service without being properly exported via sysfs.

Cc: stable@vger.kernel.org
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm mpath: delay requeuing while path initialization is in progress
Bart Van Assche [Thu, 27 Apr 2017 17:11:16 +0000 (10:11 -0700)]
dm mpath: delay requeuing while path initialization is in progress

Requeuing a request immediately while path initialization is ongoing
causes high CPU usage, something that is undesired.  Hence delay
requeuing while path initialization is in progress.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm mpath: avoid that path removal can trigger an infinite loop
Bart Van Assche [Thu, 27 Apr 2017 17:11:15 +0000 (10:11 -0700)]
dm mpath: avoid that path removal can trigger an infinite loop

If blk_get_request() fails, check whether the failure is due to a path
being removed.  If that is the case, fail the path by triggering a call
to fail_path().  This avoids that the following scenario can be
encountered while removing paths:
* CPU usage of a kworker thread jumps to 100%.
* Removing the DM device becomes impossible.

Delay requeueing if blk_get_request() returns -EBUSY or -EWOULDBLOCK,
and the queue is not dying, because in these cases immediate requeuing
is inappropriate.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm mpath: split and rename activate_path() to prepare for its expanded use
Bart Van Assche [Thu, 27 Apr 2017 17:11:14 +0000 (10:11 -0700)]
dm mpath: split and rename activate_path() to prepare for its expanded use

activate_path() is renamed to activate_path_work() which now calls
activate_or_offline_path().  activate_or_offline_path() will be used
by the next commit.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm ioctl: prevent stack leak in dm ioctl call
Adrian Salido [Thu, 27 Apr 2017 17:32:55 +0000 (10:32 -0700)]
dm ioctl: prevent stack leak in dm ioctl call

When calling a dm ioctl that doesn't process any data
(IOCTL_FLAGS_NO_PARAMS), the contents of the data field in struct
dm_ioctl are left initialized.  Current code is incorrectly extending
the size of data copied back to user, causing the contents of kernel
stack to be leaked to user.  Fix by only copying contents before data
and allow the functions processing the ioctl to override.

Cc: stable@vger.kernel.org
Signed-off-by: Adrian Salido <salidoa@google.com>
Reviewed-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm integrity: use previously calculated log2 of sectors_per_block
Mikulas Patocka [Wed, 26 Apr 2017 22:39:47 +0000 (18:39 -0400)]
dm integrity: use previously calculated log2 of sectors_per_block

The log2 of sectors_per_block was already calculated, so we don't have
to use the ilog2 function.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm integrity: use hex2bin instead of open-coded variant
Mikulas Patocka [Thu, 27 Apr 2017 15:49:33 +0000 (11:49 -0400)]
dm integrity: use hex2bin instead of open-coded variant

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm crypt: replace custom implementation of hex2bin()
Andy Shevchenko [Thu, 27 Apr 2017 13:52:04 +0000 (16:52 +0300)]
dm crypt: replace custom implementation of hex2bin()

There is no need to have a duplication of the generic library, i.e. hex2bin().
Replace the open coded variant.

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agoblk-mq-sched: alloate reserved tags out of normal pool
Jens Axboe [Thu, 27 Apr 2017 13:45:46 +0000 (07:45 -0600)]
blk-mq-sched: alloate reserved tags out of normal pool

At least one driver, mtip32xx, has a hard coded dependency on
the value of the reserved tag used for internal commands. While
that should really be fixed up, for now let's ensure that we just
bypass the scheduler tags an allocation marked as reserved. They
are used for house keeping or error handling, so we can safely
ignore them in the scheduler.

Tested-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agomtip32xx: use runtime tag to initialize command header
Ming Lei [Thu, 27 Apr 2017 13:45:18 +0000 (07:45 -0600)]
mtip32xx: use runtime tag to initialize command header

mtip32xx supposes that 'request_idx' passed to .init_request()
is tag of the request, and use that as request's tag to initialize
command header.

After MQ IO scheduler is in, request tag assigned isn't same with
the request index anymore, so cause strange hardware failure on
mtip32xx, even whole system panic is triggered.

This patch fixes the issue by initializing command header via
request's real tag.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoscsi: Implement blk_mq_ops.show_rq()
Bart Van Assche [Wed, 26 Apr 2017 20:47:57 +0000 (13:47 -0700)]
scsi: Implement blk_mq_ops.show_rq()

Show the SCSI CDB for pending SCSI commands in
/sys/kernel/debug/block/*/mq/*/dispatch and */rq_list. An example
of how SCSI commands are displayed by this code:

ffff8801703245c0 {.op=READ, .cmd_flags=META PRIO, .rq_flags=DONTPREP IO_STAT STATS, .tag=14, .internal_tag=-1, .cmd=Read(10) 28 00 2a 81 1b 30 00 00 08 00}

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: <linux-scsi@vger.kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: Add blk_mq_ops.show_rq()
Bart Van Assche [Wed, 26 Apr 2017 20:47:56 +0000 (13:47 -0700)]
blk-mq: Add blk_mq_ops.show_rq()

This new callback function will be used in the next patch to show
more information about SCSI requests.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: Show operation, cmd_flags and rq_flags names
Bart Van Assche [Wed, 26 Apr 2017 20:47:55 +0000 (13:47 -0700)]
blk-mq: Show operation, cmd_flags and rq_flags names

Show the operation name, .cmd_flags and .rq_flags as names instead
of numbers.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: Make blk_flags_show() callers append a newline character
Bart Van Assche [Wed, 26 Apr 2017 20:47:54 +0000 (13:47 -0700)]
blk-mq: Make blk_flags_show() callers append a newline character

This patch does not change any functionality but makes it possible
to produce a single line of output with multiple flag-to-name
translations.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: Move the "state" debugfs attribute one level down
Bart Van Assche [Wed, 26 Apr 2017 20:47:53 +0000 (13:47 -0700)]
blk-mq: Move the "state" debugfs attribute one level down

Move the "state" attribute from the top level to the "mq" directory
as requested by Omar.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: Unregister debugfs attributes earlier
Bart Van Assche [Wed, 26 Apr 2017 20:47:52 +0000 (13:47 -0700)]
blk-mq: Unregister debugfs attributes earlier

We currently call blk_mq_free_queue() from blk_cleanup_queue()
before we unregister the debugfs attributes for that queue in
blk_release_queue(). This leaves a window open during which
accessing most of the mq debugfs attributes would cause a
use-after-free. Additionally, the "state" attribute allows
running the queue, which we should not do after the queue has
entered the "dead" state. Fix both cases by unregistering the
debugfs attributes before freeing queue resources starts.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: Only unregister hctxs for which registration succeeded
Bart Van Assche [Wed, 26 Apr 2017 20:47:51 +0000 (13:47 -0700)]
blk-mq: Only unregister hctxs for which registration succeeded

Hctx unregistration involves calling kobject_del(). kobject_del()
must not be called if kobject_add() has not been called. Hence in
the error path only unregister hctxs for which registration succeeded.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq-debugfs: Rename functions for registering and unregistering the mq directory
Bart Van Assche [Wed, 26 Apr 2017 20:47:50 +0000 (13:47 -0700)]
blk-mq-debugfs: Rename functions for registering and unregistering the mq directory

Since the blk_mq_debugfs_*register_hctxs() functions register and
unregister all attributes under the "mq" directory, rename these
into blk_mq_debugfs_*register_mq().

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: Let blk_mq_debugfs_register() look up the queue name
Bart Van Assche [Wed, 26 Apr 2017 20:47:49 +0000 (13:47 -0700)]
blk-mq: Let blk_mq_debugfs_register() look up the queue name

A later patch will move the call of blk_mq_debugfs_register() to
a function to which the queue name is not passed as an argument.
To avoid having to add a 'name' argument to multiple callers, let
blk_mq_debugfs_register() look up the queue name.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: Register <dev>/queue/mq after having registered <dev>/queue
Bart Van Assche [Wed, 26 Apr 2017 20:47:48 +0000 (13:47 -0700)]
blk-mq: Register <dev>/queue/mq after having registered <dev>/queue

A later patch in this series will modify blk_mq_debugfs_register()
such that it uses q->kobj.parent to determine the name of a
request queue. Hence make sure that that pointer is initialized
before blk_mq_debugfs_register() is called. To avoid lock inversion,
protect sysfs / debugfs registration with the queue sysfs_lock
instead of the global mutex all_q_mutex.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoide-pm: always pass 0 error to ide_complete_rq in ide_do_devset
Christoph Hellwig [Wed, 26 Apr 2017 07:34:22 +0000 (09:34 +0200)]
ide-pm: always pass 0 error to ide_complete_rq in ide_do_devset

The caller only looks at the scsi_request result field anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoide-pm: always pass 0 error to __blk_end_request_all
Christoph Hellwig [Wed, 26 Apr 2017 07:34:21 +0000 (09:34 +0200)]
ide-pm: always pass 0 error to __blk_end_request_all

ide_pm_execute_rq exectures a PM request synchronously, and in the failure
case where it calls __blk_end_request_all it never checks the error field
passed to the end_io callback, so don't bother setting it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoscsi_transport_sas: always pass 0 error to blk_end_request_all
Christoph Hellwig [Wed, 26 Apr 2017 07:34:20 +0000 (09:34 +0200)]
scsi_transport_sas: always pass 0 error to blk_end_request_all

The SAS transport queues are only used by bsg, and bsg always looks at
the scsi_request results and never add the error passed in the end_io
callback.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agodm crypt: remove obsolete references to per-CPU state
Eric Biggers [Fri, 31 Mar 2017 05:18:48 +0000 (22:18 -0700)]
dm crypt: remove obsolete references to per-CPU state

dm-crypt used to use separate crypto transforms for each CPU, but this
is no longer the case.  To avoid confusion, fix up obsolete comments and
rename setup_essiv_cpu().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agolightnvm: fix possible memory leak in pblk_bb_discovery()
Wei Yongjun [Tue, 25 Apr 2017 16:15:30 +0000 (16:15 +0000)]
lightnvm: fix possible memory leak in pblk_bb_discovery()

'blks' is malloced in pblk_bb_discovery() and should be freed
before leaving from the nvm_get_tgt_bb_tbl() error handling cases,
otherwise it will cause memory leak. Also skip assign blks to
rlun->bb_list when error.

Fixes: a4bd217b4326 ("lightnvm: physical block device (pblk) target")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agovirtio_blk: Fix English description of VIRTIO_BLK_SCSI
Jean Delvare [Tue, 25 Apr 2017 04:07:10 +0000 (22:07 -0600)]
virtio_blk: Fix English description of VIRTIO_BLK_SCSI

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: 97b50a654d5d ("virtio_blk: make SCSI passthrough support configurable")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agodm verity: switch to using asynchronous hash crypto API
Gilad Ben-Yossef [Sun, 19 Feb 2017 12:46:07 +0000 (14:46 +0200)]
dm verity: switch to using asynchronous hash crypto API

Use of the synchronous digest API limits dm-verity to using pure
CPU based algorithm providers and rules out the use of off CPU
algorithm providers which are normally asynchronous by nature,
potentially freeing CPU cycles.

This can reduce performance per Watt in situations such as during
boot time when a lot of concurrent file accesses are made to the
protected volume.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
CC: Eric Biggers <ebiggers3@gmail.com>
CC: Ondrej Mosnáček <omosnacek+linux-crypto@gmail.com>
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm crypt: use WQ_HIGHPRI for the IO and crypt workqueues
Tim Murray [Fri, 21 Apr 2017 09:11:36 +0000 (11:11 +0200)]
dm crypt: use WQ_HIGHPRI for the IO and crypt workqueues

Running dm-crypt with workqueues at the standard priority results in IO
competing for CPU time with standard user apps, which can lead to
pipeline bubbles and seriously degraded performance.  Move to using
WQ_HIGHPRI workqueues to protect against that.

Signed-off-by: Tim Murray <timmurray@google.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm crypt: rewrite (wipe) key in crypto layer using random data
Ondrej Kozina [Mon, 24 Apr 2017 12:21:53 +0000 (14:21 +0200)]
dm crypt: rewrite (wipe) key in crypto layer using random data

The message "key wipe" used to wipe real key stored in crypto layer by
rewriting it with zeroes.  Since commit 28856a9 ("crypto: xts -
consolidate sanity check for keys") this no longer works in FIPS mode
for XTS.

While running in FIPS mode the crypto key part has to differ from the
tweak key.

Fixes: 28856a9 ("crypto: xts - consolidate sanity check for keys")
Cc: stable@vger.kernel.org
Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm mpath: requeue after a small delay if blk_get_request() fails
Bart Van Assche [Fri, 7 Apr 2017 23:50:44 +0000 (16:50 -0700)]
dm mpath: requeue after a small delay if blk_get_request() fails

If blk_get_request() returns ENODEV then multipath_clone_and_map()
causes a request to be requeued immediately. This can cause a kworker
thread to spend 100% of the CPU time of a single core in
__blk_mq_run_hw_queue() and also can cause device removal to never
finish.

Avoid this by only requeuing after a delay if blk_get_request() fails.
Additionally, reduce the requeue delay.

Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm era: save spacemap metadata root after the pre-commit
Somasundaram Krishnasamy [Fri, 7 Apr 2017 19:14:55 +0000 (12:14 -0700)]
dm era: save spacemap metadata root after the pre-commit

When committing era metadata to disk, it doesn't always save the latest
spacemap metadata root in superblock. Due to this, metadata is getting
corrupted sometimes when reopening the device. The correct order of update
should be, pre-commit (shadows spacemap root), save the spacemap root
(newly shadowed block) to in-core superblock and then the final commit.

Cc: stable@vger.kernel.org
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm thin: fix a memory leak when passing discard bio down
Dennis Yang [Tue, 18 Apr 2017 07:27:06 +0000 (15:27 +0800)]
dm thin: fix a memory leak when passing discard bio down

dm-thin does not free the discard_parent bio after all chained sub
bios finished. The following kmemleak report could be observed after
pool with discard_passdown option processes discard bios in
linux v4.11-rc7. To fix this, we drop the discard_parent bio reference
when its endio (passdown_endio) called.

unreferenced object 0xffff8803d6b29700 (size 256):
  comm "kworker/u8:0", pid 30349, jiffies 4379504020 (age 143002.776s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    01 00 00 00 00 00 00 f0 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff81a5efd9>] kmemleak_alloc+0x49/0xa0
    [<ffffffff8114ec34>] kmem_cache_alloc+0xb4/0x100
    [<ffffffff8110eec0>] mempool_alloc_slab+0x10/0x20
    [<ffffffff8110efa5>] mempool_alloc+0x55/0x150
    [<ffffffff81374939>] bio_alloc_bioset+0xb9/0x260
    [<ffffffffa018fd20>] process_prepared_discard_passdown_pt1+0x40/0x1c0 [dm_thin_pool]
    [<ffffffffa018b409>] break_up_discard_bio+0x1a9/0x200 [dm_thin_pool]
    [<ffffffffa018b484>] process_discard_cell_passdown+0x24/0x40 [dm_thin_pool]
    [<ffffffffa018b24d>] process_discard_bio+0xdd/0xf0 [dm_thin_pool]
    [<ffffffffa018ecf6>] do_worker+0xa76/0xd50 [dm_thin_pool]
    [<ffffffff81086239>] process_one_work+0x139/0x370
    [<ffffffff810867b1>] worker_thread+0x61/0x450
    [<ffffffff8108b316>] kthread+0xd6/0xf0
    [<ffffffff81a6cd1f>] ret_from_fork+0x3f/0x70
    [<ffffffffffffffff>] 0xffffffffffffffff

Cc: stable@vger.kernel.org
Signed-off-by: Dennis Yang <dennisyang@qnap.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm btree: fix for dm_btree_find_lowest_key()
Vinothkumar Raja [Fri, 7 Apr 2017 02:09:38 +0000 (22:09 -0400)]
dm btree: fix for dm_btree_find_lowest_key()

dm_btree_find_lowest_key() is giving incorrect results.  find_key()
traverses the btree correctly for finding the highest key, but there is
an error in the way it traverses the btree for retrieving the lowest
key.  dm_btree_find_lowest_key() fetches the first key of the rightmost
block of the btree instead of fetching the first key from the leftmost
block.

Fix this by conditionally passing the correct parameter to value64()
based on the @find_highest flag.

Cc: stable@vger.kernel.org
Signed-off-by: Erez Zadok <ezk@fsl.cs.sunysb.edu>
Signed-off-by: Vinothkumar Raja <vinraja@cs.stonybrook.edu>
Signed-off-by: Nidhi Panpalia <npanpalia@cs.stonybrook.edu>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm ioctl: remove double parentheses
Matthias Kaehlcke [Mon, 17 Apr 2017 18:05:03 +0000 (11:05 -0700)]
dm ioctl: remove double parentheses

The extra pair of parantheses is not needed and causes clang to generate
warnings about the DM_DEV_CREATE_CMD comparison in validate_params().

Also remove another double parentheses that doesn't cause a warning.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm: remove dummy dm_table definition
Mikulas Patocka [Wed, 19 Apr 2017 14:52:54 +0000 (10:52 -0400)]
dm: remove dummy dm_table definition

This dummy structure definition was required for RCU macros, but it
isn't required anymore, so delete it.

The dummy definition confuses the crash tool, see:
https://www.redhat.com/archives/dm-devel/2017-April/msg00197.html

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm crypt: fix large block integrity support
Mikulas Patocka [Tue, 18 Apr 2017 20:51:54 +0000 (16:51 -0400)]
dm crypt: fix large block integrity support

Previously, dm-crypt could use blocks composed of multiple 512b sectors
but it created integrity profile for each 512b sector (it padded it with
zeroes).  Fix dm-crypt so that the integrity profile is sent for each
block not each sector.

The user must use the same block size in the DM crypt and integrity
targets.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm integrity: support larger block sizes
Mikulas Patocka [Tue, 18 Apr 2017 20:51:52 +0000 (16:51 -0400)]
dm integrity: support larger block sizes

The DM integrity block size can now be 512, 1k, 2k or 4k.  Using larger
blocks reduces metadata handling overhead.  The block size can be
configured at table load time using the "block_size:<value>" option;
where <value> is expressed in bytes (defult is still 512 bytes).

It is safe to use larger block sizes with DM integrity, because the
DM integrity journal makes sure that the whole block is updated
atomically even if the underlying device doesn't support atomic writes
of that size (e.g. 4k block ontop of a 512b device).

Depends-on: 2859323e ("block: fix blk_integrity_register to use template's interval_exp if not 0")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm integrity: various small changes and cleanups
Mikulas Patocka [Tue, 18 Apr 2017 20:51:50 +0000 (16:51 -0400)]
dm integrity: various small changes and cleanups

Some coding style changes.

Fix a bug that the array test_tag has insufficient size if the digest
size of internal has is bigger than the tag size.

The function __fls is undefined for zero argument, this patch fixes
undefined behavior if the user sets zero interleave_sectors.

Fix the limit of optional arguments to 8.

Don't allocate crypt_data on the stack to avoid a BUG with debug kernel.

Rename all optional argument names to have underscores rather than
dashes.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm: mark targets that pass integrity data
Mikulas Patocka [Tue, 18 Apr 2017 20:51:48 +0000 (16:51 -0400)]
dm: mark targets that pass integrity data

A dm-crypt on dm-integrity device incorrectly advertises an integrity
profile on the DM crypt device.  It can be seen in the files
"/sys/block/dm-*/integrity/*" that both dm-integrity and dm-crypt target
advertise the integrity profile.  That is incorrect, only the
dm-integrity target should advertise the integrity profile.

A general problem in DM is that if we have a DM device that depends on
another device with an integrity profile, the upper device will always
advertise the integrity profile, even when the target driver doesn't
support handling integrity data.

Most targets don't support integrity data, so we provide a whitelist of
targets that support it (linear, delay and striped).  The targets that
support passing integrity data to the lower device are marked with the
flag DM_TARGET_PASSES_INTEGRITY.  The DM core will now advertise
integrity data on a DM device only if all the targets support the
integrity data.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm table: replace while loops with for loops
Mikulas Patocka [Tue, 18 Apr 2017 20:51:46 +0000 (16:51 -0400)]
dm table: replace while loops with for loops

Also remove some unnecessary use of uninitialized_var().

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agolightnvm: pblk: fix erase counters on error fail
Javier González [Fri, 21 Apr 2017 23:32:49 +0000 (01:32 +0200)]
lightnvm: pblk: fix erase counters on error fail

When block erases fail, these blocks are marked bad. The number of valid
blocks in the line was not updated, which could cause an infinite loop
on the erase path.

Fix this atomic counter and, in order to avoid taking an irq lock on the
interrupt context, make the erase counters atomic too.

Also, in the case that a significant number of blocks become bad in a
line, the result is the double shared metadata buffer (emeta) to stop
the pipeline until all metadata is flushed to the media. Increase the
number of metadata lines from 2 to 4 to avoid this case.

Fixes: a4bd217b4326 "lightnvm: physical block device (pblk) target"
Signed-off-by: Javier González <javier@cnexlabs.com>
Reviewed-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agolightnvm: pblk: free metadata on line alloc failure
Javier González [Fri, 21 Apr 2017 23:32:48 +0000 (01:32 +0200)]
lightnvm: pblk: free metadata on line alloc failure

When a line allocation fails, for example, due to having too many bad
blocks, free its metadata correctly.

Fixes: a4bd217b4326 "lightnvm: physical block device (pblk) target"
Signed-off-by: Javier González <javier@cnexlabs.com>
Reviewed-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agolightnvm: pblk: fix memory leak on error path
Javier González [Fri, 21 Apr 2017 23:32:47 +0000 (01:32 +0200)]
lightnvm: pblk: fix memory leak on error path

When write recovery fails, Free memory for the recovery structure.

Fixes: a4bd217b4326 "lightnvm: physical block device (pblk) target"
Signed-off-by: Javier González <javier@cnexlabs.com>
Reviewed-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agolightnvm: pblk: fix bad error check
Javier González [Fri, 21 Apr 2017 23:32:46 +0000 (01:32 +0200)]
lightnvm: pblk: fix bad error check

Fix bad error check

Fixes: a4bd217b4326 "lightnvm: physical block device (pblk) target"
Signed-off-by: Javier González <javier@cnexlabs.com>
Reviewed-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agolightnvm: pblk: fix race condition on line retry
Javier González [Fri, 21 Apr 2017 23:32:45 +0000 (01:32 +0200)]
lightnvm: pblk: fix race condition on line retry

When a pblk line fails (or is recovered), make sure to take the line
management lock.

Fixes: a4bd217b4326 "lightnvm: physical block device (pblk) target"
Signed-off-by: Javier González <javier@cnexlabs.com>
Reviewed-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblock: fix blk_integrity_register to use template's interval_exp if not 0
Mike Snitzer [Sat, 22 Apr 2017 21:22:09 +0000 (17:22 -0400)]
block: fix blk_integrity_register to use template's interval_exp if not 0

When registering an integrity profile: if the template's interval_exp is
not 0 use it, otherwise use the ilog2() of logical block size of the
provided gendisk.

This fixes a long-standing DM linear target bug where it cannot pass
integrity data to the underlying device if its logical block size
conflicts with the underlying device's logical block size.

Cc: stable@vger.kernel.org
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agolightnvm: don't print a warning for ADDR_EMPTY
Dan Carpenter [Fri, 21 Apr 2017 22:49:56 +0000 (16:49 -0600)]
lightnvm: don't print a warning for ADDR_EMPTY

Reading from ADDR_EMPTY is out of bounds.  The current code generates a
static checker warning because we check for out of bounds "lba" before
we check for ADDR_EMPTY, so the second check is always false.  It looks
like we intended ADDR_EMPTY to be a no-op without printing a warning.

Fixes: a4bd217b4326 ("lightnvm: physical block device (pblk) target")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agolightnvm: potential underflow in pblk_read_rq()
Dan Carpenter [Fri, 21 Apr 2017 22:48:40 +0000 (16:48 -0600)]
lightnvm: potential underflow in pblk_read_rq()

This is a static checker fix, and perhaps not a real bug.  The static
checker thinks that nr_secs could be negative.  It would result in
zeroing more memory than intended.  Anyway, even if it's not a bug,
changing this variable to unsigned makes the code easier to audit.

Fixes: a4bd217b4326 ("lightnvm: physical block device (pblk) target")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblock: get rid of blk_integrity_revalidate()
Ilya Dryomov [Tue, 18 Apr 2017 16:43:20 +0000 (18:43 +0200)]
block: get rid of blk_integrity_revalidate()

Commit 25520d55cdb6 ("block: Inline blk_integrity in struct gendisk")
introduced blk_integrity_revalidate(), which seems to assume ownership
of the stable pages flag and unilaterally clears it if no blk_integrity
profile is registered:

    if (bi->profile)
            disk->queue->backing_dev_info->capabilities |=
                    BDI_CAP_STABLE_WRITES;
    else
            disk->queue->backing_dev_info->capabilities &=
                    ~BDI_CAP_STABLE_WRITES;

It's called from revalidate_disk() and rescan_partitions(), making it
impossible to enable stable pages for drivers that support partitions
and don't use blk_integrity: while the call in revalidate_disk() can be
trivially worked around (see zram, which doesn't support partitions and
hence gets away with zram_revalidate_disk()), rescan_partitions() can
be triggered from userspace at any time.  This breaks rbd, where the
ceph messenger is responsible for generating/verifying CRCs.

Since blk_integrity_{un,}register() "must" be used for (un)registering
the integrity profile with the block layer, move BDI_CAP_STABLE_WRITES
setting there.  This way drivers that call blk_integrity_register() and
use integrity infrastructure won't interfere with drivers that don't
but still want stable pages.

Fixes: 25520d55cdb6 ("block: Inline blk_integrity in struct gendisk")
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 4.4+, needs backporting
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agolightnvm: propagate pblk_init return to userspace
Rakesh Pandit [Thu, 20 Apr 2017 18:23:56 +0000 (21:23 +0300)]
lightnvm: propagate pblk_init return to userspace

From userspace calling ioctl(NVM_DEV_CREATE) was returning ENOMEM for
invalid arguments even though pblk (pblk_init) was returning correctly
-EINVAL to nvm_create_tgt inside core.  This patch propagates the
correct return value to userspace.

Because pblk was introduced recently this only needs to go in 4.12.

Fixes: a4bd217b4326 ("lightnvm: physical block device (pblk) target")
Signed-off-by: Rakesh Pandit <rakesh@tuxera.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: Fix preempt count imbalance
Bart Van Assche [Fri, 21 Apr 2017 18:00:40 +0000 (12:00 -0600)]
blk-mq: Fix preempt count imbalance

Avoid that the following kernel bug gets triggered:

BUG: sleeping function called from invalid context at ./include/linux/buffer_head.h:349
in_atomic(): 1, irqs_disabled(): 0, pid: 8019, name: find
CPU: 10 PID: 8019 Comm: find Tainted: G        W I     4.11.0-rc4-dbg+ #2
Call Trace:
 dump_stack+0x68/0x93
 ___might_sleep+0x16e/0x230
 __might_sleep+0x4a/0x80
 __ext4_get_inode_loc+0x1e0/0x4e0
 ext4_iget+0x70/0xbc0
 ext4_iget_normal+0x2f/0x40
 ext4_lookup+0xb6/0x1f0
 lookup_slow+0x104/0x1e0
 walk_component+0x19a/0x330
 path_lookupat+0x4b/0x100
 filename_lookup+0x9a/0x110
 user_path_at_empty+0x36/0x40
 vfs_statx+0x67/0xc0
 SYSC_newfstatat+0x20/0x40
 SyS_newfstatat+0xe/0x10
 entry_SYSCALL_64_fastpath+0x18/0xad

This happens since the big if/else in blk_mq_make_request() doesn't
have final else section that also drops the ctx. Add that.

Fixes: b00c53e8f411 ("blk-mq: fix schedule-while-atomic with scheduler attached")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Omar Sandoval <osandov@fb.com>
Added a bit more to the commit log.

Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoMerge branch 'nvme-4.12' of git://git.infradead.org/nvme into for-4.12/block
Jens Axboe [Fri, 21 Apr 2017 17:14:22 +0000 (11:14 -0600)]
Merge branch 'nvme-4.12' of git://git.infradead.org/nvme into for-4.12/block

Christoph writes:

This is the current NVMe pile: virtualization extensions, lots of FC
updates and various misc bits.  There are a few more FC bits that didn't
make the cut, but we'd like to get this request out before the merge
window for sure.

7 years agomtip32xx: fix dereference of stack garbage
Jens Axboe [Fri, 21 Apr 2017 14:46:44 +0000 (08:46 -0600)]
mtip32xx: fix dereference of stack garbage

We need to get the command payload from the request before
we attempt to dereference it.

Fixes: 4dda4735c581 ("mtip32xx: add a status field to struct mtip_cmd")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agonvme: let dm-mpath distinguish nvme error codes
Junxiong Guan [Fri, 21 Apr 2017 10:59:07 +0000 (12:59 +0200)]
nvme: let dm-mpath distinguish nvme error codes

Currently most IOs which return the nvme error codes are retried on
the other path if those IOs returns EIO from NVMe driver. This
patch let Multipath distinguish nvme media error codes and some
generic or cmd-specific nvme error codes so that multipath will
not retry those kinds of IO, to save bandwidth.

Signed-off-by: Junxiong Guan <guanjunxiong@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
7 years agonvme/pci: Poll CQ on timeout
Keith Busch [Fri, 24 Feb 2017 22:59:28 +0000 (17:59 -0500)]
nvme/pci: Poll CQ on timeout

If an IO timeout occurs, it's helpful to know if the controller did not
post a completion or the driver missed an interrupt. While we never expect
the latter, this patch will make it possible to tell the difference so
we don't have to guess.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
7 years agonvmet_fc: Change traddr field separator to a colon
James Smart [Wed, 12 Apr 2017 22:15:18 +0000 (15:15 -0700)]
nvmet_fc: Change traddr field separator to a colon

The FC-NVME spec revised syntax to avoid comma separators.
Sync with the change in the parser for traddr on port attachments.

Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
7 years agonvme_fc: Add ls aborts on remote port teardown
James Smart [Tue, 11 Apr 2017 18:35:09 +0000 (11:35 -0700)]
nvme_fc: Add ls aborts on remote port teardown

remoteport teardown never aborted the LS opertions. Add support.

Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
7 years agonvme_fc: Move LS's to rport
James Smart [Tue, 11 Apr 2017 18:35:08 +0000 (11:35 -0700)]
nvme_fc: Move LS's to rport

Link LS's on the remoteport rather than the controller. LS's are
between nport's. Makes more sense, especially on async teardown where
the controller is torn down regardless of the LS (LS is more of a notifier
to the target of the teardown), to have them on the remoteport.

While revising ls send/done routines, issues were seen relative to
refcounting and cleanup, especially in async path. Reworked these code
paths.

Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
7 years agonvmet_fc: add missing reference in add_port
James Smart [Tue, 11 Apr 2017 18:32:32 +0000 (11:32 -0700)]
nvmet_fc: add missing reference in add_port

Add missing reference in add_port

Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
7 years agonvmet_fc: Rework target side abort handling
James Smart [Tue, 11 Apr 2017 18:32:31 +0000 (11:32 -0700)]
nvmet_fc: Rework target side abort handling

target transport:
----------------------
There are cases when there is a need to abort in-progress target
operations (writedata) so that controller termination or errors can
clean up. That can't happen currently as the abort is another target
op type, so it can't be used till the running one finishes (and it may
not).  Solve by removing the abort op type and creating a separate
downcall from the transport to the lldd to request an io to be aborted.

The transport will abort ios on queue teardown or io errors. In general
the transport tries to call the lldd abort only when the io state is
idle. Meaning: ops that transmit data (readdata or rsp) will always
finish their transmit (or the lldd will see a state on the
link or initiator port that fails the transmit) and the done call for
the operation will occur. The transport will wait for the op done
upcall before calling the abort function, and as the io is idle, the
io can be cleaned up immediately after the abort call; Similarly, ios
that are not waiting for data or transmitting data must be in the nvmet
layer being processed. The transport will wait for the nvmet layer
completion before calling the abort function, and as the io is idle,
the io can be cleaned up immediately after the abort call; As for ops
that are waiting for data (writedata), they may be outstanding
indefinitely if the lldd doesn't see a condition where the initiatior
port or link is bad. In those cases, the transport will call the abort
function and wait for the lldd's op done upcall for the operation, where
it will then clean up the io.

Additionally, if a lldd receives an ABTS and matches it to an outstanding
request in the transport, A new new transport upcall was created to abort
the outstanding request in the transport. The transport expects any
outstanding op call (readdata or writedata) will completed by the lldd and
the operation upcall made. The transport doesn't act on the reported
abort (e.g. clean up the io) until an op done upcall occurs, a new op is
attempted, or the nvmet layer completes the io processing.

fcloop:
----------------------
Updated to support the new target apis.
On fcp io aborts from the initiator, the loopback context is updated to
NULL out the half that has completed. The initiator side is immediately
called after the abort request with an io completion (abort status).
On fcp io aborts from the target, the io is stopped and the initiator side
sees it as an aborted io. Target side ops, perhaps in progress while the
initiator side is done, continue but noop the data movement as there's no
structure on the initiator side to reference.

patch also contains:
----------------------
Revised lpfc to support the new abort api

commonized rsp buffer syncing and nulling of private data based on
calling paths.

errors in op done calls don't take action on the fod. They're bad
operations which implies the fod may be bad.

Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
7 years agonvme_fcloop: split job struct from transport for req_release
James Smart [Tue, 11 Apr 2017 18:32:30 +0000 (11:32 -0700)]
nvme_fcloop: split job struct from transport for req_release

Current design has the fcloop job struct, used for both initiator and
target processing, allocated as part of the initiator request structure.
On aborts, the initiator side (based on the request) may terminate, yet
the target side wants to continue processing. the target side can't do
that if the initiator side goes away.
Revise fcloop to allocate an independent target side structure when it
starts an io from the initiator.

Added a lock to the request struct as well to synchronize pointer updates
on abort calls.

Modified target downcalls to recognize conditions where initiator has
aborted the io (thus nulled the pointer between job structs), thus
avoid referencing sgl lists which are gone and no longer making upcalls
to the initiator.

In conditions where the targetport is no longer connected, have the
initiator return an access failure rather than simulating a command
completion.

Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
7 years agonvmet_fc: add req_release to lldd api
James Smart [Tue, 11 Apr 2017 18:32:29 +0000 (11:32 -0700)]
nvmet_fc: add req_release to lldd api

With the advent of the opdone calls changing context, the lldd can no
longer assume that once the op->done call returns for RSP operations
that the request struct is no longer being accessed.

As such, revise the lldd api for a req_release callback that the
transport will call when the job is complete. This will also be used
with abort cases.

Fixed text in api header for change in io complete semantics.

Revised lpfc to support the new req_release api.

Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
7 years agonvmet_fc: add target feature flags for upcall isr contexts
James Smart [Tue, 11 Apr 2017 18:32:28 +0000 (11:32 -0700)]
nvmet_fc: add target feature flags for upcall isr contexts

Two new feature flags were added to control whether upcalls to the
transport result in context switches or stay in the calling context.

NVMET_FCTGTFEAT_CMD_IN_ISR:
  By default, if the flag is not set, the transport assumes the
  lldd is in a non-isr context and in the cpu context it should be
  for the io queue. As such, the cmd handler is called directly in the
  calling context.
  If the flag is set, indicating the upcall is an isr context, the
  transport mandates a transition to a workqueue. The workqueue assigned
  to the queue is used for the context.
NVMET_FCTGTFEAT_OPDONE_IN_ISR
  By default, if the flag is not set, the transport assumes the
  lldd is in a non-isr context and in the cpu context it should be
  for the io queue. As such, the fcp operation done callback is called
  directly in the calling context.
  If the flag is set, indicating the upcall is an isr context, the
  transport mandates a transition to a workqueue. The workqueue assigned
  to the queue is used for the context.

Updated lpfc for flags

Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
7 years agonvmet: convert from kmap to nvmet_copy_from_sgl
Logan Gunthorpe [Tue, 18 Apr 2017 23:32:15 +0000 (17:32 -0600)]
nvmet: convert from kmap to nvmet_copy_from_sgl

This is safer as it doesn't rely on the data being stored in
a single page in an sgl.

It also aids our effort to start phasing out users of sg_page. See [1].

For this we kmalloc some memory, copy to it and free at the end. Note:
we can't allocate this memory on the stack as the kbuild test robot
reports some frame size overflows on i386.

[1] https://lwn.net/Articles/720053/

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
7 years agonvme: improve performance for virtual NVMe devices
Helen Koike [Mon, 10 Apr 2017 15:51:07 +0000 (12:51 -0300)]
nvme: improve performance for virtual NVMe devices

This change provides a mechanism to reduce the number of MMIO doorbell
writes for the NVMe driver. When running in a virtualized environment
like QEMU, the cost of an MMIO is quite hefy here. The main idea for
the patch is provide the device two memory location locations:
 1) to store the doorbell values so they can be lookup without the doorbell
    MMIO write
 2) to store an event index.
I believe the doorbell value is obvious, the event index not so much.
Similar to the virtio specification, the virtual device can tell the
driver (guest OS) not to write MMIO unless you are writing past this
value.

FYI: doorbell values are written by the nvme driver (guest OS) and the
event index is written by the virtual device (host OS).

The patch implements a new admin command that will communicate where
these two memory locations reside. If the command fails, the nvme
driver will work as before without any optimizations.

Contributions:
  Eric Northup <digitaleric@google.com>
  Frank Swiderski <fes@google.com>
  Ted Tso <tytso@mit.edu>
  Keith Busch <keith.busch@intel.com>

Just to give an idea on the performance boost with the vendor
extension: Running fio [1], a stock NVMe driver I get about 200K read
IOPs with my vendor patch I get about 1000K read IOPs. This was
running with a null device i.e. the backing device simply returned
success on every read IO request.

[1] Running on a 4 core machine:
  fio --time_based --name=benchmark --runtime=30
  --filename=/dev/nvme0n1 --nrfiles=1 --ioengine=libaio --iodepth=32
  --direct=1 --invalidate=1 --verify=0 --verify_fatal=0 --numjobs=4
  --rw=randread --blocksize=4k --randrepeat=false

Signed-off-by: Rob Nelson <rlnelson@google.com>
[mlin: port for upstream]
Signed-off-by: Ming Lin <mlin@kernel.org>
[koike: updated for upstream]
Signed-off-by: Helen Koike <helen.koike@collabora.co.uk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
7 years agonvme/pci: Don't set reserved SQ create flags
Keith Busch [Tue, 4 Apr 2017 22:18:12 +0000 (18:18 -0400)]
nvme/pci: Don't set reserved SQ create flags

The QPRIO field is only valid if weighted round robin arbitration is used,
and this driver doesn't enable that controller configuration option.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
7 years agoblk-stat: kill blk_stat_rq_ddir()
Jens Axboe [Fri, 21 Apr 2017 13:55:42 +0000 (07:55 -0600)]
blk-stat: kill blk_stat_rq_ddir()

No point in providing and exporting this helper. There's just
one (real) user of it, just use rq_data_dir().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agonbd: set the max segments to USHRT_MAX
Josef Bacik [Thu, 20 Apr 2017 19:47:01 +0000 (15:47 -0400)]
nbd: set the max segments to USHRT_MAX

I lack the basic understanding of what segments mean, so we were being
limited to 512kib requests even with higher max_sectors sizes set.
Setting the maximum number of segments to unlimited allows us to
actually have arbitrarily large IO's go through NBD.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: Remove blk_mq_sched_move_to_dispatch()
Bart Van Assche [Thu, 20 Apr 2017 23:25:19 +0000 (16:25 -0700)]
blk-mq: Remove blk_mq_sched_move_to_dispatch()

commit c13660a08c8b ("blk-mq-sched: change ->dispatch_requests()
to ->dispatch_request()") removed the last user of this function.
Hence also remove the function itself.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: add might_sleep check to blk_mq_get_driver_tag()
Jens Axboe [Thu, 20 Apr 2017 23:23:13 +0000 (17:23 -0600)]
blk-mq: add might_sleep check to blk_mq_get_driver_tag()

If the caller passes in wait=true, it has to be able to block
for a driver tag. We just had a bug where flush insertion
would block on tag allocation, while we had preempt disabled.
Ensure that we catch cases like that earlier next time.

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: Fix poll_stat for new size-based bucketing.
Stephen Bates [Thu, 20 Apr 2017 22:59:11 +0000 (16:59 -0600)]
blk-mq: Fix poll_stat for new size-based bucketing.

Fixes an issue where the size of the poll_stat array in request_queue
does not match the size expected by the new size based bucketing for
IO completion polling.

Fixes: 720b8ccc4500 ("blk-mq: Add a polling specific stats function")
Signed-off-by: Stephen Bates <sbates@raithlin.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: fix schedule-while-atomic with scheduler attached
Jens Axboe [Thu, 20 Apr 2017 22:40:36 +0000 (16:40 -0600)]
blk-mq: fix schedule-while-atomic with scheduler attached

We must have dropped the ctx before we call
blk_mq_sched_insert_request() with can_block=true, otherwise we risk
that a flush request can block on insertion if we are currently out of
tags.

[   47.667190] BUG: scheduling while atomic: jbd2/sda2-8/2089/0x00000002
[   47.674493] Modules linked in: x86_pkg_temp_thermal btrfs xor zlib_deflate raid6_pq sr_mod cdre
[   47.690572] Preemption disabled at:
[   47.690584] [<ffffffff81326c7c>] blk_mq_sched_get_request+0x6c/0x280
[   47.701764] CPU: 1 PID: 2089 Comm: jbd2/sda2-8 Not tainted 4.11.0-rc7+ #271
[   47.709630] Hardware name: Dell Inc. PowerEdge T630/0NT78X, BIOS 2.3.4 11/09/2016
[   47.718081] Call Trace:
[   47.720903]  dump_stack+0x4f/0x73
[   47.724694]  ? blk_mq_sched_get_request+0x6c/0x280
[   47.730137]  __schedule_bug+0x6c/0xc0
[   47.734314]  __schedule+0x559/0x780
[   47.738302]  schedule+0x3b/0x90
[   47.741899]  io_schedule+0x11/0x40
[   47.745788]  blk_mq_get_tag+0x167/0x2a0
[   47.750162]  ? remove_wait_queue+0x70/0x70
[   47.754901]  blk_mq_get_driver_tag+0x92/0xf0
[   47.759758]  blk_mq_sched_insert_request+0x134/0x170
[   47.765398]  ? blk_account_io_start+0xd0/0x270
[   47.770679]  blk_mq_make_request+0x1b2/0x850
[   47.775766]  generic_make_request+0xf7/0x2d0
[   47.780860]  submit_bio+0x5f/0x120
[   47.784979]  ? submit_bio+0x5f/0x120
[   47.789631]  submit_bh_wbc.isra.46+0x10d/0x130
[   47.794902]  submit_bh+0xb/0x10
[   47.798719]  journal_submit_commit_record+0x190/0x210
[   47.804686]  ? _raw_spin_unlock+0x13/0x30
[   47.809480]  jbd2_journal_commit_transaction+0x180a/0x1d00
[   47.815925]  kjournald2+0xb6/0x250
[   47.820022]  ? kjournald2+0xb6/0x250
[   47.824328]  ? remove_wait_queue+0x70/0x70
[   47.829223]  kthread+0x10e/0x140
[   47.833147]  ? commit_timeout+0x10/0x10
[   47.837742]  ? kthread_create_on_node+0x40/0x40
[   47.843122]  ret_from_fork+0x29/0x40

Fixes: a4d907b6a33b ("blk-mq: streamline blk_mq_make_request")
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: Add a polling specific stats function
Stephen Bates [Fri, 7 Apr 2017 12:24:03 +0000 (06:24 -0600)]
blk-mq: Add a polling specific stats function

Rather than bucketing IO statisics based on direction only we also
bucket based on the IO size. This leads to improved polling
performance. Update the bucket callback function and use it in the
polling latency estimation.

Signed-off-by: Stephen Bates <sbates@raithlin.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-stat: convert blk-stat bucket callback to signed
Stephen Bates [Thu, 20 Apr 2017 21:29:16 +0000 (15:29 -0600)]
blk-stat: convert blk-stat bucket callback to signed

In order to allow for filtering of IO based on some other properties
of the request than direction we allow the bucket function to return
an int.

If the bucket callback returns a negative do no count it in the stats
accumulation.

Signed-off-by: Stephen Bates <sbates@raithlin.com>
Fixed up Kyber scheduler stat callback.

Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblock: remove the errors field from struct request
Christoph Hellwig [Thu, 20 Apr 2017 14:03:16 +0000 (16:03 +0200)]
block: remove the errors field from struct request

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblktrace: remove the unused block_rq_abort tracepoint
Christoph Hellwig [Thu, 20 Apr 2017 14:03:15 +0000 (16:03 +0200)]
blktrace: remove the unused block_rq_abort tracepoint

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoswim3: remove (commented out) printing of req->errors
Christoph Hellwig [Thu, 20 Apr 2017 14:03:14 +0000 (16:03 +0200)]
swim3: remove (commented out) printing of req->errors

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoataflop: switch from req->errors to req->error_count
Christoph Hellwig [Thu, 20 Apr 2017 14:03:13 +0000 (16:03 +0200)]
ataflop: switch from req->errors to req->error_count

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agofloppy: switch from req->errors to req->error_count
Christoph Hellwig [Thu, 20 Apr 2017 14:03:12 +0000 (16:03 +0200)]
floppy: switch from req->errors to req->error_count

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblock: add a error_count field to struct request
Christoph Hellwig [Thu, 20 Apr 2017 14:03:11 +0000 (16:03 +0200)]
block: add a error_count field to struct request

This is for the legacy floppy and ataflop drivers that currently abuse
->errors for this purpose.  It's stashed away in a union to not grow
the struct size, the other fields are either used by modern drivers
for different purposes or the I/O scheduler before queing the I/O
to drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: simplify __blk_mq_complete_request
Christoph Hellwig [Thu, 20 Apr 2017 14:03:10 +0000 (16:03 +0200)]
blk-mq: simplify __blk_mq_complete_request

Merge blk_mq_ipi_complete_request and blk_mq_stat_add into their only
caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoblk-mq: remove the error argument to blk_mq_complete_request
Christoph Hellwig [Thu, 20 Apr 2017 14:03:09 +0000 (16:03 +0200)]
blk-mq: remove the error argument to blk_mq_complete_request

Now that all drivers that call blk_mq_complete_requests have a
->complete callback we can remove the direct call to blk_mq_end_request,
as well as the error argument to blk_mq_complete_request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
7 years agoxen-blkfront: don't use req->errors
Christoph Hellwig [Thu, 20 Apr 2017 14:03:08 +0000 (16:03 +0200)]
xen-blkfront: don't use req->errors

xen-blkfron is the last users using rq->errros for passing back error to
blk-mq, and I'd like to get rid of that.  In the longer run the driver
should be moving more of the completion processing into .complete, but
this is the minimal change to move forward for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>