Commit Graph

4438 Commits

Author SHA1 Message Date
Christoph Hellwig 14eacf12db block: don't allow multiple bio_iov_iter_get_pages calls per bio
No caller uses bio_iov_iter_get_pages multiple times on a given bio,
and that funtionality isn't all that useful.  Removing it will make
some future changes a little easier and also simplifies the function
a bit.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-12 09:06:39 -06:00
Christoph Hellwig a10584c3cd block: refactor __bio_iov_bvec_add_pages
Return early on error, and add an unlikely annotation for that case.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-12 09:06:37 -06:00
Christoph Hellwig 8a96a0e408 block: rewrite blk_bvec_map_sg to avoid a nth_page call
The offset in scatterlists is allowed to be larger than the page size,
so don't go to great length to avoid that case and simplify the
arithmetics.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-12 09:06:36 -06:00
Jérôme Glisse a3761c3c91 block: do not leak memory in bio_copy_user_iov()
When bio_add_pc_page() fails in bio_copy_user_iov() we should free
the page we just allocated otherwise we are leaking it.

Cc: linux-block@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-10 16:14:40 -06:00
Ming Lei 1b8f21b74c blk-mq: introduce blk_mq_complete_request_sync()
In NVMe's error handler, follows the typical steps of tearing down
hardware for recovering controller:

1) stop blk_mq hw queues
2) stop the real hw queues
3) cancel in-flight requests via
	blk_mq_tagset_busy_iter(tags, cancel_request, ...)
cancel_request():
	mark the request as abort
	blk_mq_complete_request(req);
4) destroy real hw queues

However, there may be race between #3 and #4, because blk_mq_complete_request()
may run q->mq_ops->complete(rq) remotelly and asynchronously, and
->complete(rq) may be run after #4.

This patch introduces blk_mq_complete_request_sync() for fixing the
above race.

Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: James Smart <james.smart@broadcom.com>
Cc: linux-nvme@lists.infradead.org
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-10 09:57:33 -06:00
Paolo Valente eed47d19d9 block, bfq: fix use after free in bfq_bfqq_expire
The function bfq_bfqq_expire() invokes the function
__bfq_bfqq_expire(), and the latter may free the in-service bfq-queue.
If this happens, then no other instruction of bfq_bfqq_expire() must
be executed, or a use-after-free will occur.

Basing on the assumption that __bfq_bfqq_expire() invokes
bfq_put_queue() on the in-service bfq-queue exactly once, the queue is
assumed to be freed if its refcounter is equal to one right before
invoking __bfq_bfqq_expire().

But, since commit 9dee8b3b05 ("block, bfq: fix queue removal from
weights tree") this assumption is false. __bfq_bfqq_expire() may also
invoke bfq_weights_tree_remove() and, since commit 9dee8b3b05
("block, bfq: fix queue removal from weights tree"), also
the latter function may invoke bfq_put_queue(). So __bfq_bfqq_expire()
may invoke bfq_put_queue() twice, and this is the actual case where
the in-service queue may happen to be freed.

To address this issue, this commit moves the check on the refcounter
of the queue right around the last bfq_put_queue() that may be invoked
on the queue.

Fixes: 9dee8b3b05 ("block, bfq: fix queue removal from weights tree")
Reported-by: Dmitrii Tcvetkov <demfloro@demfloro.ru>
Reported-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Dmitrii Tcvetkov <demfloro@demfloro.ru>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-10 07:54:38 -06:00
Ming Lei b21e11c5c8 block: fix build warning in merging bvecs
Commit f6970f83ef ("block: don't check if adjacent bvecs in one bio can
be mergeable") changes bvec merge by only considering two bvecs from
different bios. However, if the former bio doesn't inlcude any io bvec,
then the following warning may be triggered:

 warning: ‘bvec.bv_offset’ may be used uninitialized in this function [-Wmaybe-uninitialized]

In practice, it shouldn't be triggered.

Fixes it by adding check on former bio, the check shouldn't add any cost
given 'bio->bi_iter' can be hit in cache.

Reported-by: Jens Axboe <axboe@kernel.dk>
Fixes: f6970f83ef ("block: don't check if adjacent bvecs in one bio can be mergeable")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-08 10:57:10 -06:00
Angelo Ruocco 636b8fe86b block, bfq: fix some typos in comments
Some of the comments in the bfq files had typos. This patch fixes them.

Signed-off-by: Angelo Ruocco <angeloruocco90@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-08 10:05:43 -06:00
Hisao Tanabe d0b0a81acb block: remove unused variable 'def'
The 'def' local variable became unused after commit f382fb0bce ("block: remove
legacy IO schedulers"), let's remove it.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hisao Tanabe <xtanabe@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-08 08:13:12 -06:00
David Kozub a80f36cc64 block: sed-opal: rename next to execute_steps
As the function is responsible for executing the individual steps supplied
in the steps argument, execute_steps is a more descriptive name than the
rather generic next.

Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:13 -06:00
David Kozub 0af2648ec3 block: sed-opal: don't repeat opal_discovery0 in each steps array
Originally each of the opal functions that call next include
opal_discovery0 in the array of steps. This is superfluous and
can be done always inside next.

Acked-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:13 -06:00
David Kozub 3db87236cf block: sed-opal: pass steps via argument rather than via opal_dev
The steps argument is only read by the next function, so it can
be passed directly as an argument rather than via opal_dev.

Normally, the steps is an array on the stack, so the pointer stops
being valid then the function that set opal_dev.steps returns.
If opal_dev.steps was not set to NULL before return it would become
a dangling pointer. When the steps are passed as argument this
becomes easier to see and more difficult to misuse.

Acked-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:13 -06:00
David Kozub 372be40844 block: sed-opal: use named Opal tokens instead of integer literals
Replace integer literals by Opal tokens defined in opal_proto.h where
possible.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:13 -06:00
David Kozub 3fff234b85 block: sed-opal: unify retrieval of table columns
Instead of having multiple places defining the same argument list to get
a specific column of a sed-opal table, provide a generic version and
call it from those functions.

Co-authored-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:13 -06:00
David Kozub a4ddbd1b7b block: sed-opal: add token for OPAL_LIFECYCLE
Define OPAL_LIFECYCLE token and use it instead of literals in
get_lsp_lifecycle.

Acked-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:13 -06:00
Jonas Rabenstein 285599590e block: sed-opal: split generation of bytestring header and content
Split the header generation from the (normal) memcpy part if a
bytestring is copied into the command buffer. This allows in-place
generation of the bytestring content. For example, copy_from_user may be
used without an intermediate buffer.

Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:12 -06:00
Jonas Rabenstein b2f9c6eb3f block: sed-opal: print failed function address
Add function address (and if available its symbol) to the message if a
step function fails.

Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:12 -06:00
David Kozub b68f09ecde block: sed-opal: reuse response_get_token to decrease code duplication
response_get_token had already been in place, its functionality had
been duplicated within response_get_{u64,bytestring} with the same error
handling. Unify the handling by reusing response_get_token within the
other functions.

Co-authored-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:12 -06:00
David Kozub 7d9b62ae2a block: sed-opal: unify error handling of responses
response_get_{string,u64} include error handling for argument resp being
NULL but response_get_token does not handle this.

Make all three of response_get_{string,u64,token} handle NULL resp in
the same way.

Co-authored-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:12 -06:00
David Kozub e8b2922459 block: sed-opal: unify cmd start
Every step starts with resetting the cmd buffer as well as the comid and
constructs the appropriate OPAL_CALL command. Consequently, those
actions may be combined into one generic function. On should take care
that the opening and closing tokens for the argument list are already
emitted by cmd_start and cmd_finalize respectively and thus must not be
additionally added.

Co-authored-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:12 -06:00
David Kozub 78d584ca31 block: sed-opal: close parameter list in cmd_finalize
Every step ends by calling cmd_finalize (via finalize_and_send)
yet every step adds the token OPAL_ENDLIST on its own. Moving
this into cmd_finalize decreases code duplication.

Co-authored-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:12 -06:00
Jonas Rabenstein e2821a50b1 block: sed-opal: unify space check in add_token_*
All add_token_* functions have a common set of conditions that have to
be checked. Use a common function for those checks in order to avoid
different behaviour as well as code duplication.

Acked-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Co-authored-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:12 -06:00
Jonas Rabenstein 1b6b75b013 block: sed-opal: use correct macro for method length
Also the values of OPAL_UID_LENGTH and OPAL_METHOD_LENGTH are the same,
it is weird to use OPAL_UID_LENGTH for the definition of the methods.

Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:12 -06:00
David Kozub 1e815b33c5 block: sed-opal: fix typos and formatting
This should make no change in functionality.
The formatting changes were triggered by checkpatch.pl.

Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:12 -06:00
David Kozub 78bf47353b block: sed-opal: fix IOC_OPAL_ENABLE_DISABLE_MBR
The implementation of IOC_OPAL_ENABLE_DISABLE_MBR handled the value
opal_mbr_data.enable_disable incorrectly: enable_disable is expected
to be one of OPAL_MBR_ENABLE(0) or OPAL_MBR_DISABLE(1). enable_disable
was passed directly to set_mbr_done and set_mbr_enable_disable where
is was interpreted as either OPAL_TRUE(1) or OPAL_FALSE(0). The end
result was that calling IOC_OPAL_ENABLE_DISABLE_MBR with OPAL_MBR_ENABLE
actually disabled the shadow MBR and vice versa.

This patch adds correct conversion from OPAL_MBR_DISABLE/ENABLE to
OPAL_FALSE/TRUE. The change affects existing programs using
IOC_OPAL_ENABLE_DISABLE_MBR but this is typically used only once when
setting up an Opal drive.

Acked-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 11:09:12 -06:00
Christoph Hellwig 72deb455b5 block: remove CONFIG_LBDAF
Currently support for 64-bit sector_t and blkcnt_t is optional on 32-bit
architectures.  These types are required to support block device and/or
file sizes larger than 2 TiB, and have generally defaulted to on for
a long time.  Enabling the option only increases the i386 tinyconfig
size by 145 bytes, and many data structures already always use
64-bit values for their in-core and on-disk data structures anyway,
so there should not be a large change in dynamic memory usage either.

Dropping this option removes a somewhat weird non-default config that
has cause various bugs or compiler warnings when actually used.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 10:48:35 -06:00
Bart Van Assche fd9c40f64c block: Revert v5.0 blk_mq_request_issue_directly() changes
blk_mq_try_issue_directly() can return BLK_STS*_RESOURCE for requests that
have been queued. If that happens when blk_mq_try_issue_directly() is called
by the dm-mpath driver then dm-mpath will try to resubmit a request that is
already queued and a kernel crash follows. Since it is nontrivial to fix
blk_mq_request_issue_directly(), revert the blk_mq_request_issue_directly()
changes that went into kernel v5.0.

This patch reverts the following commits:
* d6a51a97c0 ("blk-mq: replace and kill blk_mq_request_issue_directly") # v5.0.
* 5b7a6f128a ("blk-mq: issue directly with bypass 'false' in blk_mq_sched_insert_requests") # v5.0.
* 7f556a44e6 ("blk-mq: refactor the code of issue request directly") # v5.0.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: James Smart <james.smart@broadcom.com>
Cc: Dongli Zhang <dongli.zhang@oracle.com>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: <stable@vger.kernel.org>
Reported-by: Laurence Oberman <loberman@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Fixes: 7f556a44e6 ("blk-mq: refactor the code of issue request directly") # v5.0.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-05 09:40:46 -06:00
Johannes Thumshirn 2b24e6f63a block: bio: ensure newly added bio flags don't override BVEC_POOL_IDX
With the introduction of BIO_NO_PAGE_REF we've used up all available bits
in bio::bi_flags.

Convert the defines of the flags to an enum and add a BUILD_BUG_ON() call
to make sure no-one adds a new one and thus overrides the BVEC_POOL_IDX
causing crashes.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-04 09:30:37 -06:00
Dongli Zhang bcc816dfe5 blk-mq: do not reset plug->rq_count before the list is sorted
We would never be able to sort the list if we first reset plug->rq_count
which is used in conditional check later.

Fixes: ce5b009cff ("block: improve logic around when to sort a plug list")
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-04 08:37:34 -06:00
Yufen Yu ff3b74b8e1 blk-mq: add trace block plug and unplug for multiple queues
For now, we just trace plug for single queue device or drivers
provide .commit_rqs, and have not trace plug for multiple queues
device. But, unplug events will be recorded when call
blk_mq_flush_plug_list(). Then, trace events will be asymmetrical,
just have unplug and without plug.

This patch add trace plug and unplug for multiple queues device in
blk_mq_make_request(). After that, we can accurately trace plug and
unplug for multiple queues.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-02 08:57:05 -06:00
Shenghui Wang b9a1ff504b block: use blk_free_flush_queue() to free hctx->fq in blk_mq_init_hctx
kfree() can leak the hctx->fq->flush_rq field.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-02 08:20:06 -06:00
Ming Lei f6970f83ef block: don't check if adjacent bvecs in one bio can be mergeable
Now both passthrough and FS IO have supported multi-page bvec, and
bvec merging has been handled actually when adding page to bio, then
adjacent bvecs won't be mergeable any more if they belong to same bio.

So only try to merge bvecs if they are from different bios.

Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 12:11:48 -06:00
Ming Lei 16e3e41877 block: reuse __blk_bvec_map_sg() for mapping page sized bvec
Inside __blk_segment_map_sg(), page sized bvec mapping is optimized
a bit with one standalone branch.

So reuse __blk_bvec_map_sg() to do that.

Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 12:11:48 -06:00
Ming Lei cae6c2e54c block: remove argument of 'request_queue' from __blk_bvec_map_sg
The argument of 'request_queue' isn't used by __blk_bvec_map_sg(),
so remove it.

Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 12:11:48 -06:00
Ming Lei 489fbbcb51 block: enable multi-page bvec for passthrough IO
Now block IO stack is basically ready for supporting multi-page bvec,
however it isn't enabled on passthrough IO.

One reason is that passthrough IO is dispatched to LLD directly and bio
split is bypassed, so the bio has to be built correctly for dispatch to
LLD from the beginning.

Implement multi-page support for passthrough IO by limitting each bvec
as block device's segment and applying all kinds of queue limit in
blk_add_pc_page(). Then we don't need to calculate segments any more for
passthrough IO any more, turns out code is simplified much.

Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 12:11:39 -06:00
Ming Lei 190470871a block: put the same page when adding it to bio
When the added page is merged to last same page in bio_add_pc_page(),
the user may need to put this page for avoiding page leak.

bio_map_user_iov() needs this kind of handling, and now it deals with
it by itself in hack style.

Moves the handling of put page into __bio_add_pc_page(), so
bio_map_user_iov() may be simplified a bit, and maybe more users
can benefit from this change.

Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 12:11:34 -06:00
Ming Lei 5919482e22 block: check if page is mergeable in one helper
Now the check for deciding if one page is mergeable to current bvec
becomes a bit complicated, and we need to reuse the code before
adding pc page.

So move the check in one dedicated helper.

No function change.

Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 12:11:30 -06:00
Ming Lei 5a8ce240d4 block: cleanup bio_add_pc_page
REQ_PC is out of date, so replace it with passthrough IO.

Also remove the local variable of 'prev' since we can reuse
the top local variable of 'bvec'.

No function change.

Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 12:11:25 -06:00
Ming Lei fd7d8d4232 block: don't merge adjacent bvecs to one segment in bio blk_queue_split
For normal filesystem IO, each page is added via blk_add_page(),
in which bvec(page) merge has been handled already, and basically
not possible to merge two adjacent bvecs in one bio.

So not try to merge two adjacent bvecs in blk_queue_split().

Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 12:11:21 -06:00
Ming Lei db5ebd6edd block: avoid to break XEN by multi-page bvec
XEN has special page merge requirement, see xen_biovec_phys_mergeable().
We can't merge pages into one bvec simply for XEN.

So move XEN's specific check on page merge into __bio_try_merge_page(),
then abvoid to break XEN by multi-page bvec.

Cc: ris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: xen-devel@lists.xenproject.org
Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 12:11:17 -06:00
Ming Lei 0383ad4374 block: pass page to xen_biovec_phys_mergeable
xen_biovec_phys_mergeable() only needs .bv_page of the 2nd bio bvec
for checking if the two bvecs can be merged, so pass page to
xen_biovec_phys_mergeable() directly.

No function change.

Cc: ris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: xen-devel@lists.xenproject.org
Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 12:11:13 -06:00
Francesco Pollicino fffca087d5 block, bfq: save & resume weight on a queue merge/split
bfq saves the state of a queue each time a merge occurs, to be
able to resume such a state when the queue is associated again
with its original process, on a split.

Unfortunately bfq does not save & restore also the weight of the
queue. If the weight is not correctly resumed when the queue is
recycled, then the weight of the recycled queue could differ
from the weight of the original queue.

This commit adds the missing save & resume of the weight.

Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Francesco Pollicino <fra.fra.800@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 08:15:40 -06:00
Francesco Pollicino 1e66413c4f block, bfq: print SHARED instead of pid for shared queues in logs
The function "bfq_log_bfqq" prints the pid of the process
associated with the queue passed as input.

Unfortunately, if the queue is shared, then more than one process
is associated with the queue. The pid that gets printed in this
case is the pid of one of the associated processes.
Which process gets printed depends on the exact sequence of merge
events the queue underwent. So printing such a pid is rather
useless and above all is often rather confusing because it
reports a random pid between those of the associated processes.

This commit addresses this issue by printing SHARED instead of a pid
if the queue is shared.

Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Francesco Pollicino <fra.fra.800@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 08:15:40 -06:00
Paolo Valente 84a746891e block, bfq: always protect newly-created queues from existing active queues
If many bfq_queues belonging to the same group happen to be created
shortly after each other, then the processes associated with these
queues have typically a common goal. In particular, bursts of queue
creations are usually caused by services or applications that spawn
many parallel threads/processes. Examples are systemd during boot, or
git grep. If there are no other active queues, then, to help these
processes get their job done as soon as possible, the best thing to do
is to reach a high throughput. To this goal, it is usually better to
not grant either weight-raising or device idling to the queues
associated with these processes. And this is exactly what BFQ
currently does.

There is however a drawback: if, in contrast, some other queues are
already active, then the newly created queues must be protected from
the I/O flowing through the already existing queues. In this case, the
best thing to do is the opposite as in the other case: it is much
better to grant weight-raising and device idling to the newly-created
queues, if they deserve it. This commit addresses this issue by doing
so if there are already other active queues.

This change also helps eliminating false positives, which occur when
the newly-created queues do not belong to an actual large burst of
creations, but some background task (e.g., a service) happens to
trigger the creation of new queues in the middle, i.e., very close to
when the victim queues are created. These false positive may cause
total loss of control on process latencies.

Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 08:15:40 -06:00
Paolo Valente 7074f076ff block, bfq: do not tag totally seeky queues as soft rt
Sync random I/O is likely to be confused with soft real-time I/O,
because it is characterized by limited throughput and apparently
isochronous arrival pattern. To avoid false positives, this commits
prevents bfq_queues containing only random (seeky) I/O from being
tagged as soft real-time.

Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 08:15:40 -06:00
Paolo Valente 8cacc5ab3e block, bfq: do not merge queues on flash storage with queueing
To boost throughput with a set of processes doing interleaved I/O
(i.e., a set of processes whose individual I/O is random, but whose
merged cumulative I/O is sequential), BFQ merges the queues associated
with these processes, i.e., redirects the I/O of these processes into a
common, shared queue. In the shared queue, I/O requests are ordered by
their position on the medium, thus sequential I/O gets dispatched to
the device when the shared queue is served.

Queue merging costs execution time, because, to detect which queues to
merge, BFQ must maintain a list of the head I/O requests of active
queues, ordered by request positions. Measurements showed that this
costs about 10% of BFQ's total per-request processing time.

Request processing time becomes more and more critical as the speed of
the underlying storage device grows. Yet, fortunately, queue merging
is basically useless on the very devices that are so fast to make
request processing time critical. To reach a high throughput, these
devices must have many requests queued at the same time. But, in this
configuration, the internal scheduling algorithms of these devices do
also the job of queue merging: they reorder requests so as to obtain
as much as possible a sequential I/O pattern. As a consequence, with
processes doing interleaved I/O, the throughput reached by one such
device is likely to be the same, with and without queue merging.

In view of this fact, this commit disables queue merging, and all
related housekeeping, for non-rotational devices with internal
queueing. The total, single-lock-protected, per-request processing
time of BFQ drops to, e.g., 1.9 us on an Intel Core i7-2760QM@2.40GHz
(time measured with simple code instrumentation, and using the
throughput-sync.sh script of the S suite [1], in performance-profiling
mode). To put this result into context, the total,
single-lock-protected, per-request execution time of the lightest I/O
scheduler available in blk-mq, mq-deadline, is 0.7 us (mq-deadline is
~800 LOC, against ~10500 LOC for BFQ).

Disabling merging provides a further, remarkable benefit in terms of
throughput. Merging tends to make many workloads artificially more
uneven, mainly because of shared queues remaining non empty for
incomparably more time than normal queues. So, if, e.g., one of the
queues in a set of merged queues has a higher weight than a normal
queue, then the shared queue may inherit such a high weight and, by
staying almost always active, may force BFQ to perform I/O plugging
most of the time. This evidently makes it harder for BFQ to let the
device reach a high throughput.

As a practical example of this problem, and of the benefits of this
commit, we measured again the throughput in the nasty scenario
considered in previous commit messages: dbench test (in the Phoronix
suite), with 6 clients, on a filesystem with journaling, and with the
journaling daemon enjoying a higher weight than normal processes. With
this commit, the throughput grows from ~150 MB/s to ~200 MB/s on a
PLEXTOR PX-256M5 SSD. This is the same peak throughput reached by any
of the other I/O schedulers. As such, this is also likely to be the
maximum possible throughput reachable with this workload on this
device, because I/O is mostly random, and the other schedulers
basically just pass I/O requests to the drive as fast as possible.

[1] https://github.com/Algodev-github/S

Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Francesco Pollicino <fra.fra.800@gmail.com>
Signed-off-by: Alessio Masola <alessio.masola@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 08:15:40 -06:00
Paolo Valente 2341d662e9 block, bfq: tune service injection basing on request service times
The processes associated with a bfq_queue, say Q, may happen to
generate their cumulative I/O at a lower rate than the rate at which
the device could serve the same I/O. This is rather probable, e.g., if
only one process is associated with Q and the device is an SSD. It
results in Q becoming often empty while in service. If BFQ is not
allowed to switch to another queue when Q becomes empty, then, during
the service of Q, there will be frequent "service holes", i.e., time
intervals during which Q gets empty and the device can only consume
the I/O already queued in its hardware queues. This easily causes
considerable losses of throughput.

To counter this problem, BFQ implements a request injection mechanism,
which tries to fill the above service holes with I/O requests taken
from other bfq_queues. The hard part in this mechanism is finding the
right amount of I/O to inject, so as to both boost throughput and not
break Q's bandwidth and latency guarantees. To this goal, the current
version of this mechanism measures the bandwidth enjoyed by Q while it
is being served, and tries to inject the maximum possible amount of
extra service that does not cause Q's bandwidth to decrease too
much.

This solution has an important shortcoming. For bandwidth measurements
to be stable and reliable, Q must remain in service for a much longer
time than that needed to serve a single I/O request. Unfortunately,
this does not hold with many workloads. This commit addresses this
issue by changing the way the amount of injection allowed is
dynamically computed. It tunes injection as a function of the service
times of single I/O requests of Q, instead of Q's
bandwidth. Single-request service times are evidently meaningful even
if Q gets very few I/O requests completed while it is in service.

As a testbed for this new solution, we measured the throughput reached
by BFQ for one of the nastiest workloads and configurations for this
scheduler: the workload generated by the dbench test (in the Phoronix
suite), with 6 clients, on a filesystem with journaling, and with the
journaling daemon enjoying a higher weight than normal processes.
With this commit, the throughput grows from ~100 MB/s to ~150 MB/s on
a PLEXTOR PX-256M5.

Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Francesco Pollicino <fra.fra.800@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 08:15:39 -06:00
Paolo Valente fb53ac6cd0 block, bfq: do not idle for lowest-weight queues
In most cases, it is detrimental for throughput to plug I/O dispatch
when the in-service bfq_queue becomes temporarily empty (plugging is
performed to wait for the possible arrival, soon, of new I/O from the
in-service queue). There is however a case where plugging is needed
for service guarantees. If a bfq_queue, say Q, has a higher weight
than some other active bfq_queue, and is sync, i.e., contains sync
I/O, then, to guarantee that Q does receive a higher share of the
throughput than other lower-weight queues, it is necessary to plug I/O
dispatch when Q remains temporarily empty while being served.

For this reason, BFQ performs I/O plugging when some active bfq_queue
has a higher weight than some other active bfq_queue. But this is
unnecessarily overkill. In fact, if the in-service bfq_queue actually
has a weight lower than or equal to the other queues, then the queue
*must not* be guaranteed a higher share of the throughput than the
other queues. So, not plugging I/O cannot cause any harm to the
queue. And can boost throughput.

Taking advantage of this fact, this commit does not plug I/O for sync
bfq_queues with a weight lower than or equal to the weights of the
other queues. Here is an example of the resulting throughput boost
with the dbench workload, which is particularly nasty for BFQ. With
the dbench test in the Phoronix suite, BFQ reaches its lowest total
throughput with 6 clients on a filesystem with journaling, in case the
journaling daemon has a higher weight than normal processes. Before
this commit, the total throughput was ~80 MB/sec on a PLEXTOR PX-256M5,
after this commit it is ~100 MB/sec.

Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 08:15:39 -06:00
Paolo Valente 778c02a236 block, bfq: increase idling for weight-raised queues
If a sync bfq_queue has a higher weight than some other queue, and
remains temporarily empty while in service, then, to preserve the
bandwidth share of the queue, it is necessary to plug I/O dispatching
until a new request arrives for the queue. In addition, a timeout
needs to be set, to avoid waiting for ever if the process associated
with the queue has actually finished its I/O.

Even with the above timeout, the device is however not fed with new
I/O for a while, if the process has finished its I/O. If this happens
often, then throughput drops and latencies grow. For this reason, the
timeout is kept rather low: 8 ms is the current default.

Unfortunately, such a low value may cause, on the opposite end, a
violation of bandwidth guarantees for a process that happens to issue
new I/O too late. The higher the system load, the higher the
probability that this happens to some process. This is a problem in
scenarios where service guarantees matter more than throughput. One
important case are weight-raised queues, which need to be granted a
very high fraction of the bandwidth.

To address this issue, this commit lower-bounds the plugging timeout
for weight-raised queues to 20 ms. This simple change provides
relevant benefits. For example, on a PLEXTOR PX-256M5S, with which
gnome-terminal starts in 0.6 seconds if there is no other I/O in
progress, the same applications starts in
- 0.8 seconds, instead of 1.2 seconds, if ten files are being read
  sequentially in parallel
- 1 second, instead of 2 seconds, if, in parallel, five files are
  being read sequentially, and five more files are being written
  sequentially

Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 08:14:47 -06:00
Konstantin Khlebnikov 42b1bd33dc block/bfq: fix ifdef for CONFIG_BFQ_GROUP_IOSCHED=y
Replace BFQ_GROUP_IOSCHED_ENABLED with CONFIG_BFQ_GROUP_IOSCHED.
Code under these ifdefs never worked, something might be broken.

Fixes: 0471559c2f ("block, bfq: add/remove entity weights correctly")
Fixes: 73d5811849 ("block, bfq: consider also ioprio classes in symmetry detection")
Reviewed-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 06:56:15 -06:00
Jens Axboe e861857545 blk-mq: fix sbitmap ws_active for shared tags
We now wrap sbitmap waitqueues in an active counter, so we can avoid
iterating wakeups unless we have waiters there. This works as long as
everyone that's manipulating the waitqueues use the proper helpers. For
the tag wait case for shared tags, however, we add ourselves to the
waitqueue without incrementing/decrementing the ->ws_active count. This
means that wakeups can take a long time to happen.

Fix this by manually doing the inc/dec as needed for the wait queue
handling.

Reported-by: Michael Leun <kbug@newton.leun.net>
Tested-by: Michael Leun <kbug@newton.leun.net>
Cc: stable@vger.kernel.org
Reviewed-by: Omar Sandoval <osandov@fb.com>
Fixes: 5d2ee7122c ("sbitmap: optimize wakeup check")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-25 13:05:47 -06:00
Yufen Yu 85fae294e1 blk-mq: update comment for blk_mq_hctx_has_pending()
For now, blk_mq_hctx_has_pending() checks any of ctx, hctx->dispatch
or io scheduler have pending work. So, update the comment accordingly.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-24 10:26:17 -06:00
Yufen Yu 13f0638152 blk-mq: use blk_mq_put_driver_tag() to put tag
Expect arguments, blk_mq_put_driver_tag_hctx() and blk_mq_put_driver_tag()
is same. We can just use argument 'request' to put tag by blk_mq_put_driver_tag().
Then we can remove the unused blk_mq_put_driver_tag_hctx().

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-24 10:26:16 -06:00
Linus Torvalds 1bdd3dbfff io_uring-20190323
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Merge tag 'io_uring-20190323' of git://git.kernel.dk/linux-block

Pull io_uring fixes and improvements from Jens Axboe:
 "The first five in this series are heavily inspired by the work Al did
  on the aio side to fix the races there.

  The last two re-introduce a feature that was in io_uring before it got
  merged, but which I pulled since we didn't have a good way to have
  BVEC iters that already have a stable reference. These aren't
  necessarily related to block, it's just how io_uring pins fixed
  buffers"

* tag 'io_uring-20190323' of git://git.kernel.dk/linux-block:
  block: add BIO_NO_PAGE_REF flag
  iov_iter: add ITER_BVEC_FLAG_NO_REF flag
  io_uring: mark me as the maintainer
  io_uring: retry bulk slab allocs as single allocs
  io_uring: fix poll races
  io_uring: fix fget/fput handling
  io_uring: add prepped flag
  io_uring: make io_read/write return an integer
  io_uring: use regular request ref counts
2019-03-23 10:25:12 -07:00
Bart Van Assche 537d71b3f7 blkcg: Fix kernel-doc warnings
Avoid that the following warnings are reported when building with W=1:

block/blk-cgroup.c:1755: warning: Function parameter or member 'q' not described in 'blkcg_schedule_throttle'
block/blk-cgroup.c:1755: warning: Function parameter or member 'use_memdelay' not described in 'blkcg_schedule_throttle'
block/blk-cgroup.c:1779: warning: Function parameter or member 'blkg' not described in 'blkcg_add_delay'
block/blk-cgroup.c:1779: warning: Function parameter or member 'now' not described in 'blkcg_add_delay'
block/blk-cgroup.c:1779: warning: Function parameter or member 'delta' not described in 'blkcg_add_delay'

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-20 14:39:09 -06:00
Bart Van Assche 373e915cd8 blk-iolatency: #include "blk.h"
This patch avoids that the following warning is reported when building
with W=1:

block/blk-iolatency.c:734:5: warning: no previous prototype for 'blk_iolatency_init' [-Wmissing-prototypes]

Cc: Josef Bacik <jbacik@fb.com>
Fixes: d706751215 ("block: introduce blk-iolatency io controller") # v4.19
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-20 14:19:38 -06:00
Bart Van Assche e6c987120e block: Unexport blk_mq_add_to_requeue_list()
This function is not used outside the block layer core. Hence unexport it.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-20 14:19:36 -06:00
Yufen Yu 29ece8b435 block: add BLK_MQ_POLL_CLASSIC for hybrid poll and return EINVAL for unexpected value
For q->poll_nsec == -1, means doing classic poll, not hybrid poll.
We introduce a new flag BLK_MQ_POLL_CLASSIC to replace -1, which
may make code much easier to read.

Additionally, since val is an int obtained with kstrtoint(), val can be
a negative value other than -1, so return -EINVAL for that case.

Thanks to Damien Le Moal for some good suggestion.

Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-20 14:02:07 -06:00
Jens Axboe 399254aaf4 block: add BIO_NO_PAGE_REF flag
If bio_iov_iter_get_pages() is called on an iov_iter that is flagged
with NO_REF, then we don't need to add a page reference for the pages
that we add.

Add BIO_NO_PAGE_REF to track this in the bio, so IO completion knows
not to drop a reference to these pages.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-18 10:44:48 -06:00
Yufen Yu 684b73245c blk-mq: use blk_mq_sched_mark_restart_hctx to set RESTART
Let blk_mq_mark_tag_wait() use the blk_mq_sched_mark_restart_hctx()
to set BLK_MQ_S_SCHED_RESTART.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-18 08:14:51 -06:00
Linus Torvalds 11efae3506 for-5.1/block-post-20190315
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Merge tag 'for-5.1/block-post-20190315' of git://git.kernel.dk/linux-block

Pull more block layer changes from Jens Axboe:
 "This is a collection of both stragglers, and fixes that came in after
  I finalized the initial pull. This contains:

   - An MD pull request from Song, with a few minor fixes

   - Set of NVMe patches via Christoph

   - Pull request from Konrad, with a few fixes for xen/blkback

   - pblk fix IO calculation fix (Javier)

   - Segment calculation fix for pass-through (Ming)

   - Fallthrough annotation for blkcg (Mathieu)"

* tag 'for-5.1/block-post-20190315' of git://git.kernel.dk/linux-block: (25 commits)
  blkcg: annotate implicit fall through
  nvme-tcp: support C2HData with SUCCESS flag
  nvmet: ignore EOPNOTSUPP for discard
  nvme: add proper write zeroes setup for the multipath device
  nvme: add proper discard setup for the multipath device
  nvme: remove nvme_ns_config_oncs
  nvme: disable Write Zeroes for qemu controllers
  nvmet-fc: bring Disconnect into compliance with FC-NVME spec
  nvmet-fc: fix issues with targetport assoc_list list walking
  nvme-fc: reject reconnect if io queue count is reduced to zero
  nvme-fc: fix numa_node when dev is null
  nvme-fc: use nr_phys_segments to determine existence of sgl
  nvme-loop: init nvmet_ctrl fatal_err_work when allocate
  nvme: update comment to make the code easier to read
  nvme: put ns_head ref if namespace fails allocation
  nvme-trace: fix cdw10 buffer overrun
  nvme: don't warn on block content change effects
  nvme: add get-feature to admin cmds tracer
  md: Fix failed allocation of md_register_thread
  It's wrong to add len to sector_nr in raid10 reshape twice
  ...
2019-03-16 12:36:39 -07:00
Nikolay Borisov b5420237ec mm: refactor readahead defines in mm.h
All users of VM_MAX_READAHEAD actually convert it to kbytes and then to
pages. Define the macro explicitly as (SZ_128K / PAGE_SIZE). This
simplifies the expression in every filesystem. Also rename the macro to
VM_READAHEAD_PAGES to properly convey its meaning. Finally remove unused
VM_MIN_READAHEAD

[akpm@linux-foundation.org: fix fs/io_uring.c, per Stephen]
Link: http://lkml.kernel.org/r/20181221144053.24318-1-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-12 10:04:01 -07:00
Linus Torvalds 92fff53b71 SCSI misc on 20190306
This is mostly update of the usual drivers: arcmsr, qla2xxx, lpfc,
 hisi_sas, target/iscsi and target/core.  Additionally Christoph
 refactored gdth as part of the dma changes.  The major mid-layer
 change this time is the removal of bidi commands and with them the
 whole of the osd/exofs driver and filesystem.
 
 Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "This is mostly update of the usual drivers: arcmsr, qla2xxx, lpfc,
  hisi_sas, target/iscsi and target/core.

  Additionally Christoph refactored gdth as part of the dma changes. The
  major mid-layer change this time is the removal of bidi commands and
  with them the whole of the osd/exofs driver and filesystem. This is a
  major simplification for block and mq in particular"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (240 commits)
  scsi: cxgb4i: validate tcp sequence number only if chip version <= T5
  scsi: cxgb4i: get pf number from lldi->pf
  scsi: core: replace GFP_ATOMIC with GFP_KERNEL in scsi_scan.c
  scsi: mpt3sas: Add missing breaks in switch statements
  scsi: aacraid: Fix missing break in switch statement
  scsi: kill command serial number
  scsi: csiostor: drop serial_number usage
  scsi: mvumi: use request tag instead of serial_number
  scsi: dpt_i2o: remove serial number usage
  scsi: st: osst: Remove negative constant left-shifts
  scsi: ufs-bsg: Allow reading descriptors
  scsi: ufs: Allow reading descriptor via raw upiu
  scsi: ufs-bsg: Change the calling convention for write descriptor
  scsi: ufs: Remove unused device quirks
  Revert "scsi: ufs: disable vccq if it's not needed by UFS device"
  scsi: megaraid_sas: Remove a bunch of set but not used variables
  scsi: clean obsolete return values of eh_timed_out
  scsi: sd: Optimal I/O size should be a multiple of physical block size
  scsi: MAINTAINERS: SCSI initiator and target tweaks
  scsi: fcoe: make use of fip_mode enum complete
  ...
2019-03-09 16:53:47 -08:00
Linus Torvalds 38e7571c07 io_uring-2019-03-06
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Merge tag 'io_uring-2019-03-06' of git://git.kernel.dk/linux-block

Pull io_uring IO interface from Jens Axboe:
 "Second attempt at adding the io_uring interface.

  Since the first one, we've added basic unit testing of the three
  system calls, that resides in liburing like the other unit tests that
  we have so far. It'll take a while to get full coverage of it, but
  we're working towards it. I've also added two basic test programs to
  tools/io_uring. One uses the raw interface and has support for all the
  various features that io_uring supports outside of standard IO, like
  fixed files, fixed IO buffers, and polled IO. The other uses the
  liburing API, and is a simplified version of cp(1).

  This adds support for a new IO interface, io_uring.

  io_uring allows an application to communicate with the kernel through
  two rings, the submission queue (SQ) and completion queue (CQ) ring.
  This allows for very efficient handling of IOs, see the v5 posting for
  some basic numbers:

    https://lore.kernel.org/linux-block/20190116175003.17880-1-axboe@kernel.dk/

  Outside of just efficiency, the interface is also flexible and
  extendable, and allows for future use cases like the upcoming NVMe
  key-value store API, networked IO, and so on. It also supports async
  buffered IO, something that we've always failed to support in the
  kernel.

  Outside of basic IO features, it supports async polled IO as well.
  This particular feature has already been tested at Facebook months ago
  for flash storage boxes, with 25-33% improvements. It makes polled IO
  actually useful for real world use cases, where even basic flash sees
  a nice win in terms of efficiency, latency, and performance. These
  boxes were IOPS bound before, now they are not.

  This series adds three new system calls. One for setting up an
  io_uring instance (io_uring_setup(2)), one for submitting/completing
  IO (io_uring_enter(2)), and one for aux functions like registrating
  file sets, buffers, etc (io_uring_register(2)). Through the help of
  Arnd, I've coordinated the syscall numbers so merge on that front
  should be painless.

  Jon did a writeup of the interface a while back, which (except for
  minor details that have been tweaked) is still accurate. Find that
  here:

    https://lwn.net/Articles/776703/

  Huge thanks to Al Viro for helping getting the reference cycle code
  correct, and to Jann Horn for his extensive reviews focused on both
  security and bugs in general.

  There's a userspace library that provides basic functionality for
  applications that don't need or want to care about how to fiddle with
  the rings directly. It has helpers to allow applications to easily set
  up an io_uring instance, and submit/complete IO through it without
  knowing about the intricacies of the rings. It also includes man pages
  (thanks to Jeff Moyer), and will continue to grow support helper
  functions and features as time progresses. Find it here:

    git://git.kernel.dk/liburing

  Fio has full support for the raw interface, both in the form of an IO
  engine (io_uring), but also with a small test application (t/io_uring)
  that can exercise and benchmark the interface"

* tag 'io_uring-2019-03-06' of git://git.kernel.dk/linux-block:
  io_uring: add a few test tools
  io_uring: allow workqueue item to handle multiple buffered requests
  io_uring: add support for IORING_OP_POLL
  io_uring: add io_kiocb ref count
  io_uring: add submission polling
  io_uring: add file set registration
  net: split out functions related to registering inflight socket files
  io_uring: add support for pre-mapped user IO buffers
  block: implement bio helper to add iter bvec pages to bio
  io_uring: batch io_kiocb allocation
  io_uring: use fget/fput_many() for file references
  fs: add fget_many() and fput_many()
  io_uring: support for IO polling
  io_uring: add fsync support
  Add io_uring IO interface
2019-03-08 14:48:40 -08:00
Linus Torvalds 80201fe175 for-5.1/block-20190302
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Merge tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block

Pull block layer updates from Jens Axboe:
 "Not a huge amount of changes in this round, the biggest one is that we
  finally have Mings multi-page bvec support merged. Apart from that,
  this pull request contains:

   - Small series that avoids quiescing the queue for sysfs changes that
     match what we currently have (Aleksei)

   - Series of bcache fixes (via Coly)

   - Series of lightnvm fixes (via Mathias)

   - NVMe pull request from Christoph. Nothing major, just SPDX/license
     cleanups, RR mp policy (Hannes), and little fixes (Bart,
     Chaitanya).

   - BFQ series (Paolo)

   - Save blk-mq cpu -> hw queue mapping, removing a pointer indirection
     for the fast path (Jianchao)

   - fops->iopoll() added for async IO polling, this is a feature that
     the upcoming io_uring interface will use (Christoph, me)

   - Partition scan loop fixes (Dongli)

   - mtip32xx conversion from managed resource API (Christoph)

   - cdrom registration race fix (Guenter)

   - MD pull from Song, two minor fixes.

   - Various documentation fixes (Marcos)

   - Multi-page bvec feature. This brings a lot of nice improvements
     with it, like more efficient splitting, larger IOs can be supported
     without growing the bvec table size, and so on. (Ming)

   - Various little fixes to core and drivers"

* tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block: (117 commits)
  block: fix updating bio's front segment size
  block: Replace function name in string with __func__
  nbd: propagate genlmsg_reply return code
  floppy: remove set but not used variable 'q'
  null_blk: fix checking for REQ_FUA
  block: fix NULL pointer dereference in register_disk
  fs: fix guard_bio_eod to check for real EOD errors
  blk-mq: use HCTX_TYPE_DEFAULT but not 0 to index blk_mq_tag_set->map
  block: optimize bvec iteration in bvec_iter_advance
  block: introduce mp_bvec_for_each_page() for iterating over page
  block: optimize blk_bio_segment_split for single-page bvec
  block: optimize __blk_segment_map_sg() for single-page bvec
  block: introduce bvec_nth_page()
  iomap: wire up the iopoll method
  block: add bio_set_polled() helper
  block: wire up block device iopoll method
  fs: add an iopoll method to struct file_operations
  loop: set GENHD_FL_NO_PART_SCAN after blkdev_reread_part()
  loop: do not print warn message if partition scan is successful
  block: bounce: make sure that bvec table is updated
  ...
2019-03-08 14:12:17 -08:00
Ming Lei 05b700ba60 block: fix segment calculation for passthrough IO
blk_recount_segments() can be called in bio_add_pc_page() for
calculating how many segments this bio will has after one page is added
to this bio. If the resulted segment number is beyond the queue limit,
the added page will be removed.

The try-and-fix policy requires blk_recount_segments(__blk_recalc_rq_segments)
to not consider the segment number limit. Unfortunately bvec_split_segs()
does check this limit, and causes small segment number returned to
bio_add_pc_page(), then page still may be added to the bio even though
segment number limit becomes broken.

Fixes this issue by not considering segment number limit when calcualting
bio's segment number.

Fixes: dcebd75592 ("block: use bio_for_each_bvec() to compute multi-page bvec count")
Cc: Christoph Hellwig <hch@lst.de>
Cc: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-06 09:42:54 -07:00
Ming Lei aaeee62c84 block: fix updating bio's front segment size
When the current bvec can be merged to the 1st segment, the bio's front
segment size has to be updated.

However, dcebd75592 doesn't consider that case, then bio's front
segment size may not be correct.

This patch fixes this issue.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Omar Sandoval <osandov@fb.com>
Fixes: dcebd75592 ("block: use bio_for_each_bvec() to compute multi-page bvec count")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-02 12:45:37 -07:00
Keyur Patel dfc76d11dd block: Replace function name in string with __func__
Replace hard coded function name register_blkdev with __func__, to
improve robustness and to conform to the Linux kernel coding
style. Issue found using checkpatch.

Signed-off-by: Keyur Patel <iamkeyur96@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-28 14:09:08 -07:00
zhengbin 4d7c1d3fd7 block: fix NULL pointer dereference in register_disk
If __device_add_disk-->bdi_register_owner-->bdi_register-->
bdi_register_va-->device_create_vargs fails, bdi->dev is still
NULL, __device_add_disk-->register_disk will visit bdi->dev->kobj.
This patch fixes that.

Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-28 14:01:36 -07:00
Dongli Zhang 7d76f8562f blk-mq: use HCTX_TYPE_DEFAULT but not 0 to index blk_mq_tag_set->map
Replace set->map[0] with set->map[HCTX_TYPE_DEFAULT] to avoid hardcoding.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-28 13:57:32 -07:00
Jens Axboe 6d0c48aede block: implement bio helper to add iter bvec pages to bio
For an ITER_BVEC, we can just iterate the iov and add the pages
to the bio directly. For now, we grab a reference to those pages,
and release them normally on IO completion. This isn't really needed
for the normal case of O_DIRECT from/to a file, but some of the more
esoteric use cases (like splice(2)) will unconditionally put the
pipe buffer pages when the buffers are released. Until we can manage
that case properly, ITER_BVEC pages are treated like normal pages
in terms of reference counting.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-28 08:24:23 -07:00
Ming Lei bbcbbd567c block: optimize blk_bio_segment_split for single-page bvec
Introduce a fast path for single-page bvec IO, then we can avoid
to call bvec_split_segs() unnecessarily.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-27 06:18:55 -07:00
Ming Lei 48d7727cae block: optimize __blk_segment_map_sg() for single-page bvec
Introduce a fast path for single-page bvec IO, then blk_bvec_map_sg()
can be avoided.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-27 06:18:54 -07:00
Ming Lei 4d633062c1 block: introduce bvec_nth_page()
Single-page bvec can often be seen in small BS workloads, so
introduce bvec_nth_page() for avoiding to call nth_page() unnecessarily,
which looks not cheap.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-27 06:18:52 -07:00
Ming Lei 8f4e80da76 block: bounce: make sure that bvec table is updated
Block bounce needs to allocate new page for doing IO, and the
new page has to be updated to bvec table.

Commit 6dc4f100c switches __blk_queue_bounce() to use the new
bio_for_each_segment_all() interface. Unfortunately the new
bio_for_each_segment_all() can't be used to update bvec table.

This patch fixes this issue by retrieving bvec from the table
directly, then the new allocated page can be updated to the bio.
This way is safe because the cloned bio is single page bvec.

Fixes: 6dc4f100c ("block: allow bio_for_each_segment_all() to iterate over multi-page bvec")
Cc: Christoph Hellwig <hch@lst.de>
Cc: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-21 10:58:44 -07:00
Ming Lei 49b1f22b56 block: avoid to READ fields of null bio
rq->bio can be NULL sometimes, such as flush request, so don't
read bio->bi_seg_front_size until this 'bio' is checked as valid.

Cc: Bart Van Assche <bvanassche@acm.org>
Reported-by: Bart Van Assche <bvanassche@acm.org>
Fixes: dcebd75592 ("block: use bio_for_each_bvec() to compute multi-page bvec count")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-19 09:19:06 -07:00
Linus Torvalds 24f0a48743 for-linus-20190215
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Merge tag 'for-linus-20190215' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - Ensure we insert into the hctx dispatch list, if a request is marked
   as DONTPREP (Jianchao)

 - NVMe pull request, single missing unlock on error fix (Keith)

 - MD pull request, single fix for a potentially data corrupting issue
   (Nate)

 - Floppy check_events regression fix (Yufen)

* tag 'for-linus-20190215' of git://git.kernel.dk/linux-block:
  md/raid1: don't clear bitmap bits on interrupted recovery.
  floppy: check_events callback should not return a negative number
  nvme-pci: add missing unlock for reset error
  blk-mq: insert rq with DONTPREP to hctx dispatch list when requeue
2019-02-15 09:12:28 -08:00
Jens Axboe 6fb845f0e7 Linux 5.0-rc6
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Merge tag 'v5.0-rc6' into for-5.1/block

Pull in 5.0-rc6 to avoid a dumb merge conflict with fs/iomap.c.
This is needed since io_uring is now based on the block branch,
to avoid a conflict between the multi-page bvecs and the bits
of io_uring that touch the core block parts.

* tag 'v5.0-rc6': (525 commits)
  Linux 5.0-rc6
  x86/mm: Make set_pmd_at() paravirt aware
  MAINTAINERS: Update the ocores i2c bus driver maintainer, etc
  blk-mq: remove duplicated definition of blk_mq_freeze_queue
  Blk-iolatency: warn on negative inflight IO counter
  blk-iolatency: fix IO hang due to negative inflight counter
  MAINTAINERS: unify reference to xen-devel list
  x86/mm/cpa: Fix set_mce_nospec()
  futex: Handle early deadlock return correctly
  futex: Fix barrier comment
  net: dsa: b53: Fix for failure when irq is not defined in dt
  blktrace: Show requests without sector
  mips: cm: reprime error cause
  mips: loongson64: remove unreachable(), fix loongson_poweroff().
  sit: check if IPv6 enabled before calling ip6_err_gen_icmpv6_unreach()
  geneve: should not call rt6_lookup() when ipv6 was disabled
  KVM: nVMX: unconditionally cancel preemption timer in free_nested (CVE-2019-7221)
  KVM: x86: work around leak of uninitialized stack contents (CVE-2019-7222)
  kvm: fix kvm_ioctl_create_device() reference counting (CVE-2019-6974)
  signal: Better detection of synchronous signals
  ...
2019-02-15 08:43:59 -07:00
Ming Lei 56d18f62f5 block: kill BLK_MQ_F_SG_MERGE
QUEUE_FLAG_NO_SG_MERGE has been killed, so kill BLK_MQ_F_SG_MERGE too.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15 08:40:12 -07:00
Ming Lei 2705c93742 block: kill QUEUE_FLAG_NO_SG_MERGE
Since bdced438ac ("block: setup bi_phys_segments after splitting"),
physical segment number is mainly figured out in blk_queue_split() for
fast path, and the flag of BIO_SEG_VALID is set there too.

Now only blk_recount_segments() and blk_recalc_rq_segments() use this
flag.

Basically blk_recount_segments() is bypassed in fast path given BIO_SEG_VALID
is set in blk_queue_split().

For another user of blk_recalc_rq_segments():

- run in partial completion branch of blk_update_request, which is an unusual case

- run in blk_cloned_rq_check_limits(), still not a big problem if the flag is killed
since dm-rq is the only user.

Multi-page bvec is enabled now, not doing S/G merging is rather pointless with the
current setup of the I/O path, as it isn't going to save you a significant amount
of cycles.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15 08:40:12 -07:00
Ming Lei 07173c3ec2 block: enable multipage bvecs
This patch pulls the trigger for multi-page bvecs.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15 08:40:12 -07:00
Ming Lei 6dc4f100c1 block: allow bio_for_each_segment_all() to iterate over multi-page bvec
This patch introduces one extra iterator variable to bio_for_each_segment_all(),
then we can allow bio_for_each_segment_all() to iterate over multi-page bvec.

Given it is just one mechannical & simple change on all bio_for_each_segment_all()
users, this patch does tree-wide change in one single patch, so that we can
avoid to use a temporary helper for this conversion.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15 08:40:11 -07:00
Ming Lei 862e5a5e6f block: use bio_for_each_bvec() to map sg
It is more efficient to use bio_for_each_bvec() to map sg, meantime
we have to consider splitting multipage bvec as done in blk_bio_segment_split().

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15 08:40:11 -07:00
Ming Lei dcebd75592 block: use bio_for_each_bvec() to compute multi-page bvec count
First it is more efficient to use bio_for_each_bvec() in both
blk_bio_segment_split() and __blk_recalc_rq_segments() to compute how
many multi-page bvecs there are in the bio.

Secondly once bio_for_each_bvec() is used, the bvec may need to be
splitted because its length can be very longer than max segment size,
so we have to split the big bvec into several segments.

Thirdly when splitting multi-page bvec into segments, the max segment
limit may be reached, so the bio split need to be considered under
this situation too.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15 08:40:11 -07:00
Ming Lei 1a67356e9a block: don't use bio->bi_vcnt to figure out segment number
It is wrong to use bio->bi_vcnt to figure out how many segments
there are in the bio even though CLONED flag isn't set on this bio,
because this bio may be splitted or advanced.

So always use bio_segments() in blk_recount_segments(), and it shouldn't
cause any performance loss now because the physical segment number is figured
out in blk_queue_split() and BIO_SEG_VALID is set meantime since
bdced438ac ("block: setup bi_phys_segments after splitting").

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Fixes: 76d8137a31 ("blk-merge: recaculate segment if it isn't less than max segments")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15 08:40:10 -07:00
Jianchao Wang aef1897cd3 blk-mq: insert rq with DONTPREP to hctx dispatch list when requeue
When requeue, if RQF_DONTPREP, rq has contained some driver
specific data, so insert it to hctx dispatch list to avoid any
merge. Take scsi as example, here is the trace event log (no
io scheduler, because RQF_STARTED would prevent merging),

   kworker/0:1H-339   [000] ...1  2037.209289: block_rq_insert: 8,0 R 4096 () 32768 + 8 [kworker/0:1H]
scsi_inert_test-1987  [000] ....  2037.220465: block_bio_queue: 8,0 R 32776 + 8 [scsi_inert_test]
scsi_inert_test-1987  [000] ...2  2037.220466: block_bio_backmerge: 8,0 R 32776 + 8 [scsi_inert_test]
   kworker/0:1H-339   [000] ....  2047.220913: block_rq_issue: 8,0 R 8192 () 32768 + 16 [kworker/0:1H]
scsi_inert_test-1996  [000] ..s1  2047.221007: block_rq_complete: 8,0 R () 32768 + 8 [0]
scsi_inert_test-1996  [000] .Ns1  2047.221045: block_rq_requeue: 8,0 R () 32776 + 8 [0]
   kworker/0:1H-339   [000] ...1  2047.221054: block_rq_insert: 8,0 R 4096 () 32776 + 8 [kworker/0:1H]
   kworker/0:1H-339   [000] ...1  2047.221056: block_rq_issue: 8,0 R 4096 () 32776 + 8 [kworker/0:1H]
scsi_inert_test-1986  [000] ..s1  2047.221119: block_rq_complete: 8,0 R () 32776 + 8 [0]

(32768 + 8) was requeued by scsi_queue_insert and had RQF_DONTPREP.
Then it was merged with (32776 + 8) and issued. Due to RQF_DONTPREP,
the sdb only contained the part of (32768 + 8), then only that part
was completed. The lucky thing was that scsi_io_completion detected
it and requeued the remaining part. So we didn't get corrupted data.
However, the requeue of (32776 + 8) is not expected.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-11 19:51:52 -07:00
Aleksei Zakharov fbd72127c9 block: avoid setting none scheduler if it's already none
There's no reason to freeze queue and remove scheduler
if there's no scheduler already.

Signed-off-by: Aleksei Zakharov <zakharov.a.g@yandex.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-11 08:21:40 -07:00
Aleksei Zakharov b7143fe67b block: avoid setting wbt_lat_usec to current value
There's no reason to set wbt min lat and freeze request queue
if current value is the same.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Aleksei Zakharov <zakharov.a.g@yandex.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-11 08:20:14 -07:00
Marcos Paulo de Souza 1e93642837 blk-sysfs: Rework documention of __blk_release_queue
The Notes section of the comment was removed, because now
blk_release_queue can only be executed from blk_cleanup_queue (being
called when the q->kobj reaches zero), and also blk_init_queue was removed
in a1ce35fa49.

Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-10 10:23:29 -07:00
Marcos Paulo de Souza 7585d5082e blk-cgroup: Fix doc related to blkcg_exit_queue
Since 4cf6324b17, a portion of function blk_cleanup_queue was moved to
a newly created function called blk_exit_queue, including the call of
blkcg_exit_queue. So, adjust the documenation according.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-10 08:24:08 -07:00
Jens Axboe d11a399898 block: kill QUEUE_FLAG_FLUSH_NQ
We have various helpers for setting/clearing this flag, and also
a helper to check if the queue supports queueable flushes or not.
But nobody uses them anymore, kill it with fire.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-09 15:40:24 -07:00
Linus Torvalds e5a8a11632 for-linus-20190209
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Merge tag 'for-linus-20190209' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - NVMe pull request from Christoph, fixing namespace locking when
   dealing with the effects log, and a rapid add/remove issue (Keith)

 - blktrace tweak, ensuring requests with -1 sectors are shown (Jan)

 - link power management quirk for a Smasung SSD (Hans)

 - m68k nfblock dynamic major number fix (Chengguang)

 - series fixing blk-iolatency inflight counter issue (Liu)

 - ensure that we clear ->private when setting up the aio kiocb (Mike)

 - __find_get_block_slow() rate limit print (Tetsuo)

* tag 'for-linus-20190209' of git://git.kernel.dk/linux-block:
  blk-mq: remove duplicated definition of blk_mq_freeze_queue
  Blk-iolatency: warn on negative inflight IO counter
  blk-iolatency: fix IO hang due to negative inflight counter
  blktrace: Show requests without sector
  fs: ratelimit __find_get_block_slow() failure message.
  m68k: set proper major_num when specifying module param major_num
  libata: Add NOLPM quirk for SAMSUNG MZ7TE512HMHP-000L1 SSD
  nvme-pci: fix rapid add remove sequence
  nvme: lock NS list changes while handling command effects
  aio: initialize kiocb private in case any filesystems expect it.
2019-02-09 10:26:09 -08:00
Aleksei Zakharov e5fa81408f block: avoid setting nr_requests to current value
There's no reason to freeze queue and set nr_requests value
if current value is the same.

Signed-off-by: Aleksei Zakharov <zakharov.a.g@yandex.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-08 12:43:25 -07:00
Liu Bo 2698484178 blk-mq: remove duplicated definition of blk_mq_freeze_queue
As the prototype has been defined in "include/linux/blk-mq.h", the one
in "block/blk-mq.h" can be removed then.

Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-08 12:42:29 -07:00
Liu Bo 391f552af2 Blk-iolatency: warn on negative inflight IO counter
This is to catch any unexpected negative value of inflight IO counter.

Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-08 12:42:27 -07:00
Liu Bo 8c772a9bfc blk-iolatency: fix IO hang due to negative inflight counter
Our test reported the following stack, and vmcore showed that
->inflight counter is -1.

[ffffc9003fcc38d0] __schedule at ffffffff8173d95d
[ffffc9003fcc3958] schedule at ffffffff8173de26
[ffffc9003fcc3970] io_schedule at ffffffff810bb6b6
[ffffc9003fcc3988] blkcg_iolatency_throttle at ffffffff813911cb
[ffffc9003fcc3a20] rq_qos_throttle at ffffffff813847f3
[ffffc9003fcc3a48] blk_mq_make_request at ffffffff8137468a
[ffffc9003fcc3b08] generic_make_request at ffffffff81368b49
[ffffc9003fcc3b68] submit_bio at ffffffff81368d7d
[ffffc9003fcc3bb8] ext4_io_submit at ffffffffa031be00 [ext4]
[ffffc9003fcc3c00] ext4_writepages at ffffffffa03163de [ext4]
[ffffc9003fcc3d68] do_writepages at ffffffff811c49ae
[ffffc9003fcc3d78] __filemap_fdatawrite_range at ffffffff811b6188
[ffffc9003fcc3e30] filemap_write_and_wait_range at ffffffff811b6301
[ffffc9003fcc3e60] ext4_sync_file at ffffffffa030cee8 [ext4]
[ffffc9003fcc3ea8] vfs_fsync_range at ffffffff8128594b
[ffffc9003fcc3ee8] do_fsync at ffffffff81285abd
[ffffc9003fcc3f18] sys_fsync at ffffffff81285d50
[ffffc9003fcc3f28] do_syscall_64 at ffffffff81003c04
[ffffc9003fcc3f50] entry_SYSCALL_64_after_swapgs at ffffffff81742b8e

The ->inflight counter may be negative (-1) if

1) blk-iolatency was disabled when the IO was issued,

2) blk-iolatency was enabled before this IO reached its endio,

3) the ->inflight counter is decreased from 0 to -1 in endio()

In fact the hang can be easily reproduced by the below script,

H=/sys/fs/cgroup/unified/
P=/sys/fs/cgroup/unified/test

echo "+io" > $H/cgroup.subtree_control
mkdir -p $P

echo $$ > $P/cgroup.procs

xfs_io -f -d -c "pwrite 0 4k" /dev/sdg

echo "`cat /sys/block/sdg/dev` target=1000000" > $P/io.latency

xfs_io -f -d -c "pwrite 0 4k" /dev/sdg

This fixes the problem by freezing the queue so that while
enabling/disabling iolatency, there is no inflight rq running.

Note that quiesce_queue is not needed as this only updating iolatency
configuration about which dispatching request_queue doesn't care.

Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-08 12:42:26 -07:00
Linus Torvalds 8c8e62cc98 Driver core fixes for 5.0-rc6
Here are some driver core fixes for 5.0-rc6.
 
 Well, not so much "driver core" as "debugfs".  There's a lot of
 outstanding debugfs cleanup patches coming in through different
 subsystem trees, and in that process the debugfs core was found that it
 really should return errors when something bad happens, to prevent
 random files from showing up in the root of debugfs afterward.  So
 debugfs was fixed up to handle this properly, and then two fixes for
 the relay and blk-mq code was needed as it was making invalid
 assumptions about debugfs return values.
 
 There's also a cacheinfo fix in here that resolves a tiny issue.
 
 All of these have been in linux-next for over a week with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are some driver core fixes for 5.0-rc6.

  Well, not so much "driver core" as "debugfs". There's a lot of
  outstanding debugfs cleanup patches coming in through different
  subsystem trees, and in that process the debugfs core was found that
  it really should return errors when something bad happens, to prevent
  random files from showing up in the root of debugfs afterward. So
  debugfs was fixed up to handle this properly, and then two fixes for
  the relay and blk-mq code was needed as it was making invalid
  assumptions about debugfs return values.

  There's also a cacheinfo fix in here that resolves a tiny issue.

  All of these have been in linux-next for over a week with no reported
  problems"

* tag 'driver-core-5.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  blk-mq: protect debugfs_create_files() from failures
  relay: check return of create_buf_file() properly
  debugfs: debugfs_lookup() should return NULL if not found
  debugfs: return error values, not NULL
  debugfs: fix debugfs_rename parameter checking
  cacheinfo: Keep the old value if of_property_read_u32 fails
2019-02-08 10:53:44 -08:00
Christoph Hellwig 8b3238cabd scsi: block: remove bidi support
Unused now, and another field in struct request bites the dust.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-02-05 21:30:27 -05:00
Christoph Hellwig 69ed175c19 scsi: block: remove req->special
No users left.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-02-05 21:30:09 -05:00
Christoph Hellwig 972248e911 scsi: bsg-lib: handle bidi requests without block layer help
We can just stash away the second request in struct bsg_job instead of
using the block layer req->next_rq field, allowing for the eventual removal
of the latter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-02-05 21:27:40 -05:00