Commit Graph

195 Commits

Author SHA1 Message Date
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
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
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 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
Linus Torvalds 77d0b194b2 for-4.21/block-20190102
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAlwtClAQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpicLEACpQalDy7tUp+0/5VUMTiYksBqimtCoOu59
 K9BsrRwdXnhAxBdD3a6cn442axKelg5NozdTAXFTNAFkuDUci0eBvVZFNBhuRaqY
 Cp/ub8rF81viivDvF5kO8wWC745Zj63/BQjethXrTssVI3ZOV4lK+haiuJeXOegN
 LwM64P5lHlhQkOn/FV5oDSWyrlffMrjtcqJ22Em0mxeHgneZXI0wVeJgGbbY8e33
 GWGUb+sYpDM41ZDl7vyVSIDNHKzYMSbN7hdLh3fD+EWVFwI/F+lZU/LHbO+lKt1f
 LU/mPXLrIkEvzhFwwGLQy10u6lo1US6sMoKfFcpKu8KRY4p7DyvoCLyGH2PtK2sR
 +vX1LlWPHJsN9x/5TlfOnXrR0qChzqwMU3tgzQaCF7HOEx+3Xt7HpKRffJmVMNZP
 anMqevN2OfjvpcBEs2jktAqiwmBZIPSQJ9OMqkPJIalIW4h3qDKXRKttpmWTWMeV
 sDWNGj3hpukWba01vTxYOkz8/V58+ikzM26UAjTmTU9YvQ+TZBmu+azAuisedhqE
 b66gXz8YLp6r10psSBnh1IThvhuDyjmofouWGuSWJRcEngzXbL6jDQhgqWWCzKUn
 cW8Cs4ymvSwE5Qwwgs4wY8XYwyl5L9QGgfwLx+toMvSKq/G+ONA6FQ1Crp7zx4jq
 bnNqy1iWNg==
 =KYFj
 -----END PGP SIGNATURE-----

Merge tag 'for-4.21/block-20190102' of git://git.kernel.dk/linux-block

Pull more block updates from Jens Axboe:

 - Dead code removal for loop/sunvdc (Chengguang)

 - Mark BIDI support for bsg as deprecated, logging a single dmesg
   warning if anyone is actually using it (Christoph)

 - blkcg cleanup, killing a dead function and making the tryget_closest
   variant easier to read (Dennis)

 - Floppy fixes, one fixing a regression in swim3 (Finn)

 - lightnvm use-after-free fix (Gustavo)

 - gdrom leak fix (Wenwen)

 - a set of drbd updates (Lars, Luc, Nathan, Roland)

* tag 'for-4.21/block-20190102' of git://git.kernel.dk/linux-block: (28 commits)
  block/swim3: Fix regression on PowerBook G3
  block/swim3: Fix -EBUSY error when re-opening device after unmount
  block/swim3: Remove dead return statement
  block/amiflop: Don't log error message on invalid ioctl
  gdrom: fix a memory leak bug
  lightnvm: pblk: fix use-after-free bug
  block: sunvdc: remove redundant code
  block: loop: remove redundant code
  bsg: deprecate BIDI support in bsg
  blkcg: remove unused __blkg_release_rcu()
  blkcg: clean up blkg_tryget_closest()
  drbd: Change drbd_request_detach_interruptible's return type to int
  drbd: Avoid Clang warning about pointless switch statment
  drbd: introduce P_ZEROES (REQ_OP_WRITE_ZEROES on the "wire")
  drbd: skip spurious timeout (ping-timeo) when failing promote
  drbd: don't retry connection if peers do not agree on "authentication" settings
  drbd: fix print_st_err()'s prototype to match the definition
  drbd: avoid spurious self-outdating with concurrent disconnect / down
  drbd: do not block when adjusting "disk-options" while IO is frozen
  drbd: fix comment typos
  ...
2019-01-02 18:49:58 -08:00
Linus Torvalds 0e9da3fbf7 for-4.21/block-20181221
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAlwb7R8QHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpjiID/97oDjMhNT7rwpuMbHw855h62j1hEN/m+N3
 FI0uxivYoYZLD+eJRnMcBwHlKjrCX8iJQAcv9ffI3ThtFW7dnZT3atUacaZVR/Dt
 IrxdymdBP3qsmuaId5NYBug7rJ+AiqFJKjEvCcSPu5X397J4I3SEbzhfvYLJ/aZX
 16o0HJlVVIrcbmq1IP4HwiIIOaKXvPaw04L4z4fpeynRSWG7EAi8NLSnhlR4Rxbb
 BTiMkCTsjRCFdyO6da4fvNQKWmPGPa3bJkYy3qR99cvJCeIbQjRyCloQlWNJRRgi
 3eJpCHVxqFmN0/+DNTJVQEEr4H8o0AVucrLVct1Jc4pessenkpoUniP8vELqwlng
 Z2VHLkhTfCEmvFlk82grrYdNvGATRsrbswt/PlP4T7rBfr1IpDk8kXDWF59EL2dy
 ly35Sk3wJGHBl8qa+vEPXOAnaWdqJXuVGpwB4ifOIatOls8mOxwfZjiRc7x05/fC
 1O4rR2IfLwRqwoYHs0AJ+h6ohOSn1mkGezl2Tch1VSFcJUOHmuYvraTaUi6hblpA
 SslaAoEhO39hRBL0HsvsMeqVWM9uzqvFkLDCfNPdiA81H1258CIbo4vF8z6czCIS
 eeXnTJxVhPVbZgb3a1a93SPwM6KIDZFoIijyd+NqjpU94thlnhYD0QEcKJIKH7os
 2p4aHs6ktw==
 =TRdW
 -----END PGP SIGNATURE-----

Merge tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "This is the main pull request for block/storage for 4.21.

  Larger than usual, it was a busy round with lots of goodies queued up.
  Most notable is the removal of the old IO stack, which has been a long
  time coming. No new features for a while, everything coming in this
  week has all been fixes for things that were previously merged.

  This contains:

   - Use atomic counters instead of semaphores for mtip32xx (Arnd)

   - Cleanup of the mtip32xx request setup (Christoph)

   - Fix for circular locking dependency in loop (Jan, Tetsuo)

   - bcache (Coly, Guoju, Shenghui)
      * Optimizations for writeback caching
      * Various fixes and improvements

   - nvme (Chaitanya, Christoph, Sagi, Jay, me, Keith)
      * host and target support for NVMe over TCP
      * Error log page support
      * Support for separate read/write/poll queues
      * Much improved polling
      * discard OOM fallback
      * Tracepoint improvements

   - lightnvm (Hans, Hua, Igor, Matias, Javier)
      * Igor added packed metadata to pblk. Now drives without metadata
        per LBA can be used as well.
      * Fix from Geert on uninitialized value on chunk metadata reads.
      * Fixes from Hans and Javier to pblk recovery and write path.
      * Fix from Hua Su to fix a race condition in the pblk recovery
        code.
      * Scan optimization added to pblk recovery from Zhoujie.
      * Small geometry cleanup from me.

   - Conversion of the last few drivers that used the legacy path to
     blk-mq (me)

   - Removal of legacy IO path in SCSI (me, Christoph)

   - Removal of legacy IO stack and schedulers (me)

   - Support for much better polling, now without interrupts at all.
     blk-mq adds support for multiple queue maps, which enables us to
     have a map per type. This in turn enables nvme to have separate
     completion queues for polling, which can then be interrupt-less.
     Also means we're ready for async polled IO, which is hopefully
     coming in the next release.

   - Killing of (now) unused block exports (Christoph)

   - Unification of the blk-rq-qos and blk-wbt wait handling (Josef)

   - Support for zoned testing with null_blk (Masato)

   - sx8 conversion to per-host tag sets (Christoph)

   - IO priority improvements (Damien)

   - mq-deadline zoned fix (Damien)

   - Ref count blkcg series (Dennis)

   - Lots of blk-mq improvements and speedups (me)

   - sbitmap scalability improvements (me)

   - Make core inflight IO accounting per-cpu (Mikulas)

   - Export timeout setting in sysfs (Weiping)

   - Cleanup the direct issue path (Jianchao)

   - Export blk-wbt internals in block debugfs for easier debugging
     (Ming)

   - Lots of other fixes and improvements"

* tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-block: (364 commits)
  kyber: use sbitmap add_wait_queue/list_del wait helpers
  sbitmap: add helpers for add/del wait queue handling
  block: save irq state in blkg_lookup_create()
  dm: don't reuse bio for flushes
  nvme-pci: trace SQ status on completions
  nvme-rdma: implement polling queue map
  nvme-fabrics: allow user to pass in nr_poll_queues
  nvme-fabrics: allow nvmf_connect_io_queue to poll
  nvme-core: optionally poll sync commands
  block: make request_to_qc_t public
  nvme-tcp: fix spelling mistake "attepmpt" -> "attempt"
  nvme-tcp: fix endianess annotations
  nvmet-tcp: fix endianess annotations
  nvme-pci: refactor nvme_poll_irqdisable to make sparse happy
  nvme-pci: only set nr_maps to 2 if poll queues are supported
  nvmet: use a macro for default error location
  nvmet: fix comparison of a u16 with -1
  blk-mq: enable IO poll if .nr_queues of type poll > 0
  blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight()
  blk-mq: skip zero-queue maps in blk_mq_map_swqueue
  ...
2018-12-28 13:19:59 -08:00
Dennis Zhou 6ab2187992 blkcg: clean up blkg_tryget_closest()
The implementation of blkg_tryget_closest() wasn't super obvious and
became a point of suspicion when debugging [1]. So let's clean it up so
it's obviously not the problem.

Also add missing RCU read locking to bio_clone_blkg_association(), which
got exposed by adding the RCU read lock held check in
blkg_tryget_closest().

[1] https://lore.kernel.org/linux-block/a7e97e4b-0dd8-3a54-23b7-a0f27b17fde8@kernel.dk/

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-21 08:47:05 -07:00
Christoph Hellwig a45eb575cd block: remove the unused bio_set_pages_dirty and bio_check_pages_dirty exports
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-14 06:17:58 -07:00
Christoph Hellwig 0374e11322 block: remove the unused bio_iov_iter_get_pages export
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-14 06:17:57 -07:00
Christoph Hellwig 6c210aa596 block: remove the bio_phys_segments export
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-14 06:17:53 -07:00
Keith Busch f55adad601 block/bio: Do not zero user pages
We don't need to zero fill the bio if not using kernel allocated pages.

Fixes: f3587d76da ("block: Clear kernel memory before copying to user") # v4.20-rc2
Reported-by: Todd Aiken <taiken@mvtech.ca>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: stable@vger.kernel.org
Cc: Bart Van Assche <bvanassche@acm.org>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10 13:37:20 -07:00
Mikulas Patocka 5b18b5a737 block: delete part_round_stats and switch to less precise counting
We want to convert to per-cpu in_flight counters.

The function part_round_stats needs the in_flight counter every jiffy, it
would be too costly to sum all the percpu variables every jiffy, so it
must be deleted. part_round_stats is used to calculate two counters -
time_in_queue and io_ticks.

time_in_queue can be calculated without part_round_stats, by adding the
duration of the I/O when the I/O ends (the value is almost as exact as the
previously calculated value, except that time for in-progress I/Os is not
counted).

io_ticks can be approximated by increasing the value when I/O is started
or ended and the jiffies value has changed. If the I/Os take less than a
jiffy, the value is as exact as the previously calculated value. If the
I/Os take more than a jiffy, io_ticks can drift behind the previously
calculated value.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10 08:30:37 -07:00
Mike Snitzer 112f158f66 block: stop passing 'cpu' to all percpu stats methods
All of part_stat_* and related methods are used with preempt disabled,
so there is no need to pass cpu around to allow of them.  Just call
smp_processor_id() as needed.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10 08:30:37 -07:00
Dennis Zhou 7754f669ff blkcg: rename blkg_try_get() to blkg_tryget()
blkg reference counting now uses percpu_ref rather than atomic_t. Let's
make this consistent with css_tryget. This renames blkg_try_get to
blkg_tryget and now returns a bool rather than the blkg or %NULL.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07 22:26:38 -07:00
Dennis Zhou 6f70fb6618 blkcg: remove bio_disassociate_task()
Now that a bio only holds a blkg reference, so clean up is simply
putting back that reference. Remove bio_disassociate_task() as it just
calls bio_disassociate_blkg() and call the latter directly.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07 22:26:38 -07:00
Dennis Zhou fc5a828bfa blkcg: remove additional reference to the css
The previous patch in this series removed carrying around a pointer to
the css in blkg. However, the blkg association logic still relied on
taking a reference on the css to ensure we wouldn't fail in getting a
reference for the blkg.

Here the implicit dependency on the css is removed. The association
continues to rely on the tryget logic walking up the blkg tree. This
streamlines the three ways that association can happen: normal, swap,
and writeback.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07 22:26:37 -07:00
Dennis Zhou db6638d7d1 blkcg: remove bio->bi_css and instead use bio->bi_blkg
Prior patches ensured that any bio that interacts with a request_queue
is properly associated with a blkg. This makes bio->bi_css unnecessary
as blkg maintains a reference to blkcg already.

This removes the bio field bi_css and transfers corresponding uses to
access via bi_blkg.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07 22:26:37 -07:00
Dennis Zhou fd42df305f blkcg: associate writeback bios with a blkg
One of the goals of this series is to remove a separate reference to
the css of the bio. This can and should be accessed via bio_blkcg(). In
this patch, wbc_init_bio() now requires a bio to have a device
associated with it.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07 22:26:37 -07:00
Dennis Zhou 6a7f6d86a5 blkcg: associate a blkg for pages being evicted by swap
A prior patch in this series added blkg association to bios issued by
cgroups. There are two other paths that we want to attribute work back
to the appropriate cgroup: swap and writeback. Here we modify the way
swap tags bios to include the blkg. Writeback will be tackle in the next
patch.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07 22:26:37 -07:00
Dennis Zhou e439bedf6b blkcg: consolidate bio_issue_init() to be a part of core
bio_issue_init among other things initializes the timestamp for an IO.
Rather than have this logic handled by policies, this consolidates it to
be on the init paths (normal, clone, bounce clone).

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07 22:26:37 -07:00
Dennis Zhou 5cdf2e3fea blkcg: associate blkg when associating a device
Previously, blkg association was handled by controller specific code in
blk-throttle and blk-iolatency. However, because a blkg represents a
relationship between a blkcg and a request_queue, it makes sense to keep
the blkg->q and bio->bi_disk->queue consistent.

This patch moves association into the bio_set_dev macro(). This should
cover the majority of cases where the device is set/changed keeping the
two pointers consistent. Fallback code is added to
blkcg_bio_issue_check() to catch any missing paths.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07 22:26:37 -07:00
Dennis Zhou 892ad71f62 dm: set the static flush bio device on demand
The next patch changes the macro bio_set_dev() to associate a bio with a
blkg based on the device set. However, dm creates a static bio to be
used as the basis for cloning empty flush bios on creation. The
bio_set_dev() call in alloc_dev() will cause problems with the next
patch adding association to bio_set_dev() because the call is before the
bdev is associated with a gendisk (bd_disk is %NULL). To get around
this, set the device on the static bio every time and use that to clone
to the other bios.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07 22:26:37 -07:00
Dennis Zhou 2268c0feb0 blkcg: introduce common blkg association logic
There are 3 ways blkg association can happen: association with the
current css, with the page css (swap), or from the wbc css (writeback).

This patch handles how association is done for the first case where we
are associating bsaed on the current css. If there is already a blkg
associated, the css will be reused and association will be redone as the
request_queue may have changed.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07 22:26:36 -07:00
Dennis Zhou beea9da07d blkcg: convert blkg_lookup_create() to find closest blkg
There are several scenarios where blkg_lookup_create() can fail such as
the blkcg dying, request_queue is dying, or simply being OOM. Most
handle this by simply falling back to the q->root_blkg and calling it a
day.

This patch implements the notion of closest blkg. During
blkg_lookup_create(), if it fails to create, return the closest blkg
found or the q->root_blkg. blkg_try_get_closest() is introduced and used
during association so a bio is always attached to a blkg.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07 22:26:36 -07:00
Dennis Zhou 0fe061b9f0 blkcg: fix ref count issue with bio_blkcg() using task_css
The bio_blkcg() function turns out to be inconsistent and consequently
dangerous to use. The first part returns a blkcg where a reference is
owned by the bio meaning it does not need to be rcu protected. However,
the third case, the last line, is problematic:

	return css_to_blkcg(task_css(current, io_cgrp_id));

This can race against task migration and the cgroup dying. It is also
semantically different as it must be called rcu protected and is
susceptible to failure when trying to get a reference to it.

This patch adds association ahead of calling bio_blkcg() rather than
after. This makes association a required and explicit step along the
code paths for calling bio_blkcg(). In blk-iolatency, association is
moved above the bio_blkcg() call to ensure it will not return %NULL.

BFQ uses the old bio_blkcg() function, but I do not want to address it
in this series due to the complexity. I have created a private version
documenting the inconsistency and noting not to use it.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07 22:26:36 -07:00
Damien Le Moal e2b3fa5af7 block: Remove bio->bi_ioc
bio->bi_ioc is never set so always NULL. Remove references to it in
bio_disassociate_task() and in rq_ioc() and delete this field from
struct bio. With this change, rq_ioc() always returns
current->io_context without the need for a bio argument. Further
simplify the code and make it more readable by also removing this
helper, which also allows to simplify blk_mq_sched_assign_ioc() by
removing its bio argument.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Adam Manzanares <adam.manzanares@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-19 19:03:44 -07:00
Hannes Reinecke ca474b7389 block: copy ioprio in __bio_clone_fast() and bounce
We need to copy the io priority, too; otherwise the clone will run
with a different priority than the original one.

Fixes: 43b62ce3ff ("block: move bio io prio to a new field")
Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>

Fixed up subject, and ordered stores.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-12 10:35:25 -07:00
Linus Torvalds dc5db21865 for-linus-20181109
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAlvl3xoQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpsoUEACecROMzIey+QOJ9o0YSaK5tlBWoC1OyK72
 ncHCyxw+uW+qWa4Csosib7BRomz3E0nsQzf0b3MJiiZJGXnbfxRP0GWDrriK+635
 UeVmWQfU2Ga2QmXGpnlSSF7mHHZWOWG7hUonGUBgCOiN2tLymHrnjmmPf7TuDuav
 CliIgjan124MamohXyjcIa0EtySZmkTlJAxOtoOlxXwitLWnd28Vb3kOhG4dHXQs
 lKO94R2souY00PX/e/8GtkAf1Em+5yJea/LAcOW8+qHA1WYzDqp1/TG/STLX0MVP
 rgqg4E8j1LzCCmunaneIuSeo6yQhZPF2OHMGD8ERn+5c5RY0J4wsBAW2ZO0aqmBP
 nfv+ZdZa71NU+pEEkOe79B5l1JiQNwTCu1ay/kfSGQpAnd2ejnY6QqiLnfCEgqWG
 mcZi/JKcUst8I+MCV9vSjzl9GvMY7Wn5Fy031T4Qog2F0ZPns3FyNLuOLXXjkH7C
 h5uliwuvLV3TpVWgWfVh8R7/j3M0dLndl5G5EYHwkb7It59r4rmNfgm1llZPFhWq
 TENDvq5vLJaPXh5NIyxR1TowJNfgVembr5XiSJ7nOt8IFfJvkcfVIbQqRcpBk8vG
 ygde6xKwGSxsfRoIhNTFU0mlphFpNgske600oZkm6PZq6DnivS9/4PD77nIH7p5v
 6kR8aG43uQ==
 =Nry6
 -----END PGP SIGNATURE-----

Merge tag 'for-linus-20181109' of git://git.kernel.dk/linux-block

Pull block layer fixes from Jens Axboe:

 - Two fixes for an ubd regression, one for missing locking, and one for
   a missing initialization of a field. The latter was an old latent
   bug, but it's now visible and triggers (Me, Anton Ivanov)

 - Set of NVMe fixes via Christoph, but applied manually due to a git
   tree mixup (Christoph, Sagi)

 - Fix for a discard split regression, in three patches (Ming)

 - Update libata git trees (Geert)

 - SPDX identifier for sata_rcar (Kuninori Morimoto)

 - Virtual boundary merge fix (Johannes)

 - Preemptively clear memory we are going to pass to userspace, in case
   the driver does a short read (Keith)

* tag 'for-linus-20181109' of git://git.kernel.dk/linux-block:
  block: make sure writesame bio is aligned with logical block size
  block: cleanup __blkdev_issue_discard()
  block: make sure discard bio is aligned with logical block size
  Revert "nvmet-rdma: use a private workqueue for delete"
  nvme: make sure ns head inherits underlying device limits
  nvmet: don't try to add ns to p2p map unless it actually uses it
  sata_rcar: convert to SPDX identifiers
  ubd: fix missing initialization of io_req
  block: Clear kernel memory before copying to user
  MAINTAINERS: Fix remaining pointers to obsolete libata.git
  ubd: fix missing lock around request issue
  block: respect virtual boundary mask in bvecs
2018-11-09 16:31:51 -06:00
Keith Busch f3587d76da block: Clear kernel memory before copying to user
If the kernel allocates a bounce buffer for user read data, this memory
needs to be cleared before copying it to the user, otherwise it may leak
kernel memory to user space.

Laurence Oberman <loberman@redhat.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-07 15:41:31 -07:00
Linus Torvalds 5f21585384 for-linus-20181102
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAlvchGgQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpj/1D/4kEQx4ncnFoZk8QshHV1L++rH3BbcLjQDd
 Wbh9ZSIQdI/gHTzS6bE7x3YfcbpMWPMO3+jFawdfRiFTEjlF8vQ+mnJ+Btb3z4D6
 mGEeFGVhHExlp2a0x/Ma8YWVNlMB7BE8Tq73bZEVMY+9lbpmDW/vp7Sfa87LBDKQ
 ZmY+My+VdHN7qLtQ7t3W/HtpbU+kcXMMd3ICjK4i+ofXy6mynk4+oQ2jwyXc5L86
 UCJCsTsSRr3CgbnkW/uprHo0XHk8i7O/4C3oR+x4pAIxCCa9g+vmw0EO9fvi/2iQ
 qe8jKdm7Y09xu/TiPBa7iz45tdh0cNMJKo3OezmSF9Np+r69KL5C/U4GRPKN3Iwm
 keoqn14ScABkYMSe4ys1AdEgKD6bNUaW3r/lJxTH2oUR23mjnCLp7c4WD/G+MlbB
 CzoakQyCHTZmDFLr2Kc8bkjmpil2T2UFfmLIDAu30LWIYeSGpiIO/V+g1foJMF2f
 06ERltNvgX1BJjoh4NSWySLEf1ZtkUU60NeATRol6gwhnIyLrHsgfm6OEhqlW/7x
 Xc1BWyzX7K6c3Dskk/u5aSRyXOyRC9KkMt3/2XexeDNHkte9yMH0IgSvopPBuER8
 +iPvPjNp7ychTKZB3zpSnlqGgePTjbufIEBtO3OyUmDZKjUqxahtxkQfmPhoclu+
 XdR4ArcqNg==
 =0zM4
 -----END PGP SIGNATURE-----

Merge tag 'for-linus-20181102' of git://git.kernel.dk/linux-block

Pull block layer fixes from Jens Axboe:
 "The biggest part of this pull request is the revert of the blkcg
  cleanup series. It had one fix earlier for a stacked device issue, but
  another one was reported. Rather than play whack-a-mole with this,
  revert the entire series and try again for the next kernel release.

  Apart from that, only small fixes/changes.

  Summary:

   - Indentation fixup for mtip32xx (Colin Ian King)

   - The blkcg cleanup series revert (Dennis Zhou)

   - Two NVMe fixes. One fixing a regression in the nvme request
     initialization in this merge window, causing nvme-fc to not work.
     The other is a suspend/resume p2p resource issue (James, Keith)

   - Fix sg discard merge, allowing us to merge in cases where we didn't
     before (Jianchao Wang)

   - Call rq_qos_exit() after the queue is frozen, preventing a hang
     (Ming)

   - Fix brd queue setup, fixing an oops if we fail setting up all
     devices (Ming)"

* tag 'for-linus-20181102' of git://git.kernel.dk/linux-block:
  nvme-pci: fix conflicting p2p resource adds
  nvme-fc: fix request private initialization
  blkcg: revert blkcg cleanups series
  block: brd: associate with queue until adding disk
  block: call rq_qos_exit() after queue is frozen
  mtip32xx: clean an indentation issue, remove extraneous tabs
  block: fix the DISCARD request merge
2018-11-02 11:25:48 -07:00
Linus Torvalds 9931a07d51 Merge branch 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull AFS updates from Al Viro:
 "AFS series, with some iov_iter bits included"

* 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
  missing bits of "iov_iter: Separate type from direction and use accessor functions"
  afs: Probe multiple fileservers simultaneously
  afs: Fix callback handling
  afs: Eliminate the address pointer from the address list cursor
  afs: Allow dumping of server cursor on operation failure
  afs: Implement YFS support in the fs client
  afs: Expand data structure fields to support YFS
  afs: Get the target vnode in afs_rmdir() and get a callback on it
  afs: Calc callback expiry in op reply delivery
  afs: Fix FS.FetchStatus delivery from updating wrong vnode
  afs: Implement the YFS cache manager service
  afs: Remove callback details from afs_callback_break struct
  afs: Commit the status on a new file/dir/symlink
  afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS
  afs: Don't invoke the server to read data beyond EOF
  afs: Add a couple of tracepoints to log I/O errors
  afs: Handle EIO from delivery function
  afs: Fix TTL on VL server and address lists
  afs: Implement VL server rotation
  afs: Improve FS server rotation error handling
  ...
2018-11-01 19:58:52 -07:00
Dennis Zhou b5f2954d30 blkcg: revert blkcg cleanups series
This reverts a series committed earlier due to null pointer exception
bug report in [1]. It seems there are edge case interactions that I did
not consider and will need some time to understand what causes the
adverse interactions.

The original series can be found in [2] with a follow up series in [3].

[1] https://www.spinics.net/lists/cgroups/msg20719.html
[2] https://lore.kernel.org/lkml/20180911184137.35897-1-dennisszhou@gmail.com/
[3] https://lore.kernel.org/lkml/20181020185612.51587-1-dennis@kernel.org/

This reverts the following commits:
d459d853c2, b2c3fa5467, 101246ec02, b3b9f24f5f, e2b0989954,
f0fcb3ec89, c839e7a03f, bdc2491708, 74b7c02a9b, 5bf9a1f3b4,
a7b39b4e96, 07b05bcc32, 49f4c2dc2b, 27e6fa996c

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-01 19:59:53 -06:00
David Howells 00e2370744 iov_iter: Use accessor function
Use accessor functions to access an iterator's type and direction.  This
allows for the possibility of using some other method of determining the
type of iterator than if-chains with bitwise-AND conditions.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:40:44 +01:00
Dennis Zhou d459d853c2 blkcg: reassociate bios when make_request() is called recursively
When submitting a bio, multiple recursive calls to make_request() may
occur. This causes the initial associate done in blkcg_bio_issue_check()
to be incorrect and reference the prior request_queue. This introduces
a helper to do reassociation when make_request() is recursively called.

Fixes: a7b39b4e96 ("blkcg: always associate a bio with a blkg")
Reported-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-20 15:39:55 -06:00
Jens Axboe c0aac682fa This is the 4.19-rc6 release
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEZH8oZUiU471FcZm+ONu9yGCSaT4FAluw4MIACgkQONu9yGCS
 aT7+8xAAiYnc4khUsxeInm3z44WPfRX1+UF51frTNSY5C8Nn5nvRSnTUNLuKkkrz
 8RbwCL6UYyJxF9I/oZdHPsPOD4IxXkQY55tBjz7ZbSBIFEwYM6RJMm8mAGlXY7wq
 VyWA5MhlpGHM9DjrguB4DMRipnrSc06CVAnC+ZyKLjzblzU1Wdf2dYu+AW9pUVXP
 j4r74lFED5djPY1xfqfzEwmYRCeEGYGx7zMqT3GrrF5uFPqj1H6O5klEsAhIZvdl
 IWnJTU2coC8R/Sd17g4lHWPIeQNnMUGIUbu+PhIrZ/lDwFxlocg4BvarPXEdzgYi
 gdZzKBfovpEsSu5RCQsKWG4IGQxY7I1p70IOP9eqEFHZy77qT1YcHVAWrK1Y/bJd
 UA08gUOSzRnhKkNR3+PsaMflUOl9WkpyHECZu394cyRGMutSS50aWkavJPJ/o1Qi
 D/oGqZLLcKFyuNcchG+Met1TzY3LvYEDgSburqwqeUZWtAsGs8kmiiq7qvmXx4zV
 IcgM8ERqJ8mbfhfsXQU7hwydIrPJ3JdIq19RnM5ajbv2Q4C/qJCyAKkQoacrlKR4
 aiow/qvyNrP80rpXfPJB8/8PiWeDtAnnGhM+xySZNlw3t8GR6NYpUkIzf5TdkSb3
 C8KuKg6FY9QAS62fv+5KK3LB/wbQanxaPNruQFGe5K1iDQ5Fvzw=
 =dMl4
 -----END PGP SIGNATURE-----

Merge tag 'v4.19-rc6' into for-4.20/block

Merge -rc6 in, for two reasons:

1) Resolve a trivial conflict in the blk-mq-tag.c documentation
2) A few important regression fixes went into upstream directly, so
   they aren't in the 4.20 branch.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

* tag 'v4.19-rc6': (780 commits)
  Linux 4.19-rc6
  MAINTAINERS: fix reference to moved drivers/{misc => auxdisplay}/panel.c
  cpufreq: qcom-kryo: Fix section annotations
  perf/core: Add sanity check to deal with pinned event failure
  xen/blkfront: correct purging of persistent grants
  Revert "xen/blkfront: When purging persistent grants, keep them in the buffer"
  selftests/powerpc: Fix Makefiles for headers_install change
  blk-mq: I/O and timer unplugs are inverted in blktrace
  dax: Fix deadlock in dax_lock_mapping_entry()
  x86/boot: Fix kexec booting failure in the SEV bit detection code
  bcache: add separate workqueue for journal_write to avoid deadlock
  drm/amd/display: Fix Edid emulation for linux
  drm/amd/display: Fix Vega10 lightup on S3 resume
  drm/amdgpu: Fix vce work queue was not cancelled when suspend
  Revert "drm/panel: Add device_link from panel device to DRM device"
  xen/blkfront: When purging persistent grants, keep them in the buffer
  clocksource/drivers/timer-atmel-pit: Properly handle error cases
  block: fix deadline elevator drain for zoned block devices
  ACPI / hotplug / PCI: Don't scan for non-hotplug bridges if slot is not bridge
  drm/syncobj: Don't leak fences when WAIT_FOR_SUBMIT is set
  ...

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-01 08:58:57 -06:00
Christoph Hellwig 3dccdae54f block: merge BIOVEC_SEG_BOUNDARY into biovec_phys_mergeable
These two checks should always be performed together, so merge them into
a single helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-24 12:33:57 -06:00
Christoph Hellwig 0e253391a9 block: add a missing BIOVEC_SEG_BOUNDARY check in bio_add_pc_page
The actual recaculation of segments in __blk_recalc_rq_segments will
do this check, so there is no point in forcing it if we know it won't
succeed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-24 12:33:55 -06:00
Christoph Hellwig 6a9f5f240a block: simplify BIOVEC_PHYS_MERGEABLE
Turn the macro into an inline, move it to blk.h and simplify the
arch hooks a bit.

Also rename the function to biovec_phys_mergeable as there is no need
to shout.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-24 12:33:54 -06:00
Dennis Zhou (Facebook) 101246ec02 blkcg: rename blkg_try_get to blkg_tryget
blkg reference counting now uses percpu_ref rather than atomic_t. Let's
make this consistent with css_tryget. This renames blkg_try_get to
blkg_tryget and now returns a bool rather than the blkg or NULL.

Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21 20:29:19 -06:00
Dennis Zhou (Facebook) f0fcb3ec89 blkcg: remove additional reference to the css
The previous patch in this series removed carrying around a pointer to
the css in blkg. However, the blkg association logic still relied on
taking a reference on the css to ensure we wouldn't fail in getting a
reference for the blkg.

Here the implicit dependency on the css is removed. The association
continues to rely on the tryget logic walking up the blkg tree. This
streamlines the three ways that association can happen: normal, swap,
and writeback.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21 20:29:15 -06:00
Dennis Zhou (Facebook) c839e7a03f blkcg: remove bio->bi_css and instead use bio->bi_blkg
Prior patches ensured that all bios are now associated with some blkg.
This now makes bio->bi_css unnecessary as blkg maintains a reference to
the blkcg already.

This patch removes the field bi_css and transfers corresponding uses to
access via bi_blkg.

Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21 20:29:13 -06:00
Dennis Zhou (Facebook) 74b7c02a9b blkcg: associate a blkg for pages being evicted by swap
A prior patch in this series added blkg association to bios issued by
cgroups. There are two other paths that we want to attribute work back
to the appropriate cgroup: swap and writeback. Here we modify the way
swap tags bios to include the blkg. Writeback will be tackle in the next
patch.

Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21 20:29:09 -06:00
Dennis Zhou (Facebook) 5bf9a1f3b4 blkcg: consolidate bio_issue_init to be a part of core
bio_issue_init among other things initializes the timestamp for an IO.
Rather than have this logic handled by policies, this consolidates it to
be on the init paths (normal, clone, bounce clone).

Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21 20:29:08 -06:00
Dennis Zhou (Facebook) a7b39b4e96 blkcg: always associate a bio with a blkg
Previously, blkg's were only assigned as needed by blk-iolatency and
blk-throttle. bio->css was also always being associated while blkg was
being looked up and then thrown away in blkcg_bio_issue_check.

This patch begins the cleanup of bio->css and bio->bi_blkg by always
associating a blkg in blkcg_bio_issue_check. This tries to create the
blkg, but if it is not possible, falls back to using the root_blkg of
the request_queue. Therefore, a bio will always be associated with a
blkg. The duplicate association logic is removed from blk-throttle and
blk-iolatency.

Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21 20:29:06 -06:00
Dennis Zhou (Facebook) 07b05bcc32 blkcg: convert blkg_lookup_create to find closest blkg
There are several scenarios where blkg_lookup_create can fail. Examples
include the blkcg dying, request_queue is dying, or simply being OOM. At
the end of the day, most handle this by simply falling back to the
q->root_blkg and calling it a day.

This patch implements the notion of closest blkg. During
blkg_lookup_create, if it fails to create, return the closest blkg
found or the q->root_blkg. blkg_try_get_closest is introduced and used
during association so a bio is always attached to a blkg.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21 20:29:05 -06:00
Dennis Zhou (Facebook) 27e6fa996c blkcg: fix ref count issue with bio_blkcg using task_css
The accessor function bio_blkcg either returns the blkcg associated with
the bio or finds one in the current context. This can cause an issue
when trying to associate a bio with a blkcg. Particularly, it's the
third case that is problematic:

	return css_to_blkcg(task_css(current, io_cgrp_id));

As the above may race against task migration and the cgroup exiting, it
is not always ok to take a reference on the blkcg returned from
bio_blkcg.

This patch adds association ahead of calling bio_blkcg rather than
after. This makes association a required and explicit step along the
code paths for calling bio_blkcg. blk_get_rl is modified as well to get
a reference to the blkcg it may use and blk_put_rl will always put the
reference back. Association is also moved above the bio_blkcg call to
ensure it will not return NULL in blk-iolatency.

BFQ and CFQ utilize this flaw, but due to the complexity, I do not want
to address this in this series. I've created a private version of the
function with notes not to use it describing the flaw. Hopefully soon,
that code can be cleaned up.

Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21 20:29:02 -06:00
Omar Sandoval b57e99b4b8 block: use nanosecond resolution for iostat
Klaus Kusche reported that the I/O busy time in /proc/diskstats was not
updating properly on 4.18. This is because we started using ktime to
track elapsed time, and we convert nanoseconds to jiffies when we update
the partition counter. However, this gets rounded down, so any I/Os that
take less than a jiffy are not accounted for. Previously in this case,
the value of jiffies would sometimes increment while we were doing I/O,
so at least some I/Os were accounted for.

Let's convert the stats to use nanoseconds internally. We still report
milliseconds as before, now more accurately than ever. The value is
still truncated to 32 bits for backwards compatibility.

Fixes: 522a777566 ("block: consolidate struct request timestamp fields")
Cc: stable@vger.kernel.org
Reported-by: Klaus Kusche <klaus.kusche@computerix.info>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21 20:26:59 -06:00
Christoph Hellwig 576ed91354 block: use bio_add_page in bio_iov_iter_get_pages
Replace a nasty hack with a different nasty hack to prepare for multipage
bio_vecs.  By moving the temporary page array as far up as possible in
the space allocated for the bio_vec array we can iterate forward over it
and thus use bio_add_page.  Using bio_add_page means we'll be able to
merge physically contiguous pages once support for multipath bio_vecs is
merged.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-20 09:11:40 -06:00
Ming Lei 7759eb23fd block: remove bio_rewind_iter()
It is pointed that bio_rewind_iter() is one very bad API[1]:

1) bio size may not be restored after rewinding

2) it causes some bogus change, such as 5151842b9d (block: reset
bi_iter.bi_done after splitting bio)

3) rewinding really makes things complicated wrt. bio splitting

4) unnecessary updating of .bi_done in fast path

[1] https://marc.info/?t=153549924200005&r=1&w=2

So this patch takes Kent's suggestion to restore one bio into its original
state via saving bio iterator(struct bvec_iter) in bio_integrity_prep(),
given now bio_rewind_iter() is only used by bio integrity code.

Cc: Dmitry Monakhov <dmonakhov@openvz.org>
Cc: Hannes Reinecke <hare@suse.com>
Suggested-by: Kent Overstreet <kent.overstreet@gmail.com>
Acked-by: Kent Overstreet <kent.overstreet@gmail.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>
2018-09-06 15:12:24 -06:00