Commit Graph

5221 Commits

Author SHA1 Message Date
Linus Torvalds 64b28683de for-linus-20180204
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABCAAGBQJadzbSAAoJEPfTWPspceCmt5QP/jo6MSsNVevAQOE75Jje+qa/
 aF/BjHBdUmmI5WtPrtoz4igaJou7M2U0s8jdsc3c7uMw8dGTKc6ujIquSEn0wevY
 faJPTjWzLum3y50gwRHcrHCQIlxOe5/f9rJevW4+q76aMP3aWKjO4bgBExH+2XnA
 CaT+6d40skYt20Sy428H0yhVdDAMiQYXTeg4SssWQY9AvJSSiW7ax+vmP3r5BKpV
 dXHggwgzqDuMwLZG80Tfg4GHGv5qisIrqLOCxtXNYHDNb/aDmbTFTO2jPgobT8gW
 N2kWxsOkBayUdPw6Nt2Wlm4toQgR5GJGH04LH2vI5p4dp4Grvx/aFGvUbT7+sN1u
 g/mmqsUUnYuO5AJ8XY2s2F7ezaT6v9x8BbLHuA2vz0r5GsdFVXctZ/bXgQqkmh9i
 KLtfyOPldlczclVEuKL4xai1aXLcoBzDwyLxzbFp3+eAlhcgoSqxnMsE4fCJblCU
 dfShDChu1SbBD6dyGx8sol9cT48RFj2tBtpfcYxFW/NJJOQoh9FTqPQetYQxQ72c
 TadEf40hmw5Q2l0Hu5pwVbKHWUP0wn0VznkAOfT4VV1ysk93oExMbjgS2qh16xEZ
 oQwFDQMk3D8BXI9VwH8gUUnypkhcooMhznxSC3BQxjGn/R+byp7QEPvxSEZz/4nD
 BaBSbyAU5cpof+Eaqs4B
 =qeDb
 -----END PGP SIGNATURE-----

Merge tag 'for-linus-20180204' of git://git.kernel.dk/linux-block

Pull more block updates from Jens Axboe:
 "Most of this is fixes and not new code/features:

   - skd fix from Arnd, fixing a build error dependent on sla allocator
     type.

   - blk-mq scheduler discard merging fixes, one from me and one from
     Keith. This fixes a segment miscalculation for blk-mq-sched, where
     we mistakenly think two segments are physically contigious even
     though the request isn't carrying real data. Also fixes a bio-to-rq
     merge case.

   - Don't re-set a bit on the buffer_head flags, if it's already set.
     This can cause scalability concerns on bigger machines and
     workloads. From Kemi Wang.

   - Add BLK_STS_DEV_RESOURCE return value to blk-mq, allowing us to
     distuingish between a local (device related) resource starvation
     and a global one. The latter might happen without IO being in
     flight, so it has to be handled a bit differently. From Ming"

* tag 'for-linus-20180204' of git://git.kernel.dk/linux-block:
  block: skd: fix incorrect linux/slab_def.h inclusion
  buffer: Avoid setting buffer bits that are already set
  blk-mq-sched: Enable merging discard bio into request
  blk-mq: fix discard merge with scheduler attached
  blk-mq: introduce BLK_STS_DEV_RESOURCE
2018-02-04 11:16:35 -08:00
Linus Torvalds 0be600a5ad - DM core fixes to ensure that bio submission follows a depth-first tree
walk; this is critical to allow forward progress without the need to
   use the bioset's BIOSET_NEED_RESCUER.
 
 - Remove DM core's BIOSET_NEED_RESCUER based dm_offload infrastructure.
 
 - DM core cleanups and improvements to make bio-based DM more efficient
   (e.g. reduced memory footprint as well leveraging per-bio-data more).
 
 - Introduce new bio-based mode (DM_TYPE_NVME_BIO_BASED) that leverages
   the more direct IO submission path in the block layer; this mode is
   used by DM multipath and also optimizes targets like DM thin-pool that
   stack directly on NVMe data device.
 
 - DM multipath improvements to factor out legacy SCSI-only
   (e.g. scsi_dh) code paths to allow for more optimized support for NVMe
   multipath.
 
 - A fix for DM multipath path selectors (service-time and queue-length)
   to select paths in a more balanced way; largely academic but doesn't
   hurt.
 
 - Numerous DM raid target fixes and improvements.
 
 - Add a new DM "unstriped" target that enables Intel to workaround
   firmware limitations in some NVMe drives that are striped internally
   (this target also works when stacked above the DM "striped" target).
 
 - Various Documentation fixes and improvements.
 
 - Misc. cleanups and fixes across various DM infrastructure and targets
   (e.g. bufio, flakey, log-writes, snapshot).
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJacgwPAAoJEMUj8QotnQNaEw0H/0XRTcg8/lRuGl46kdeI3PgR
 ZxUy4XgUrCLiACWO5yCU/nKipB32+3xTlTDTBcjmaBfX8HolH147Pasb1KdHqLVC
 dOWLMpjlFztb5fnuOMitJA05qQAbgRlZ52QdVk/FDo9yWicgWjQZduh8aYX53pHw
 6XOYWzSFAXQcaduPdz6TLiPw479xBwIpXxQbrO09f4qt3Ub4bqknEhzFXc+6M7zl
 ejmW/bG2Qg6WmsfAuaAhFTV0LpTPSEzvaq9TfR7yqFU3DvDIAi7Yh8eQinIUDo4u
 txpOGoESRAMPAMKH0/UJdr/u7jTsfgJox4QEavWfnViPvkouah5KdjVOL1veZ5U=
 =R3dN
 -----END PGP SIGNATURE-----

Merge tag 'for-4.16/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - DM core fixes to ensure that bio submission follows a depth-first
   tree walk; this is critical to allow forward progress without the
   need to use the bioset's BIOSET_NEED_RESCUER.

 - Remove DM core's BIOSET_NEED_RESCUER based dm_offload infrastructure.

 - DM core cleanups and improvements to make bio-based DM more efficient
   (e.g. reduced memory footprint as well leveraging per-bio-data more).

 - Introduce new bio-based mode (DM_TYPE_NVME_BIO_BASED) that leverages
   the more direct IO submission path in the block layer; this mode is
   used by DM multipath and also optimizes targets like DM thin-pool
   that stack directly on NVMe data device.

 - DM multipath improvements to factor out legacy SCSI-only (e.g.
   scsi_dh) code paths to allow for more optimized support for NVMe
   multipath.

 - A fix for DM multipath path selectors (service-time and queue-length)
   to select paths in a more balanced way; largely academic but doesn't
   hurt.

 - Numerous DM raid target fixes and improvements.

 - Add a new DM "unstriped" target that enables Intel to workaround
   firmware limitations in some NVMe drives that are striped internally
   (this target also works when stacked above the DM "striped" target).

 - Various Documentation fixes and improvements.

 - Misc cleanups and fixes across various DM infrastructure and targets
   (e.g. bufio, flakey, log-writes, snapshot).

* tag 'for-4.16/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (69 commits)
  dm cache: Documentation: update default migration_throttling value
  dm mpath selector: more evenly distribute ties
  dm unstripe: fix target length versus number of stripes size check
  dm thin: fix trailing semicolon in __remap_and_issue_shared_cell
  dm table: fix NVMe bio-based dm_table_determine_type() validation
  dm: various cleanups to md->queue initialization code
  dm mpath: delay the retry of a request if the target responded as busy
  dm mpath: return DM_MAPIO_DELAY_REQUEUE if QUEUE_IO or PG_INIT_REQUIRED
  dm mpath: return DM_MAPIO_REQUEUE on blk-mq rq allocation failure
  dm log writes: fix max length used for kstrndup
  dm: backfill missing calls to mutex_destroy()
  dm snapshot: use mutex instead of rw_semaphore
  dm flakey: check for null arg_name in parse_features()
  dm thin: extend thinpool status format string with omitted fields
  dm thin: fixes in thin-provisioning.txt
  dm thin: document representation of <highest mapped sector> when there is none
  dm thin: fix documentation relative to low water mark threshold
  dm cache: be consistent in specifying sectors and SI units in cache.txt
  dm cache: delete obsoleted paragraph in cache.txt
  dm cache: fix grammar in cache-policies.txt
  ...
2018-01-31 11:05:47 -08:00
Linus Torvalds 040639b7fc Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md
Pull MD updates from Shaohua Li:
 "Some small fixes for MD:

   - fix raid5-cache potential problems if raid5 cache isn't fully
     recovered

   - fix a wait-within-wait warning in raid1/10

   - make raid5-PPL support disks with writeback cache enabled"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  raid5-ppl: PPL support for disks with write-back cache enabled
  md/r5cache: print more info of log recovery
  md/raid1,raid10: silence warning about wait-within-wait
  md: introduce new personality funciton start()
2018-01-31 11:03:38 -08:00
Ming Lei 86ff7c2a80 blk-mq: introduce BLK_STS_DEV_RESOURCE
This status is returned from driver to block layer if device related
resource is unavailable, but driver can guarantee that IO dispatch
will be triggered in future when the resource is available.

Convert some drivers to return BLK_STS_DEV_RESOURCE.  Also, if driver
returns BLK_STS_RESOURCE and SCHED_RESTART is set, rerun queue after
a delay (BLK_MQ_DELAY_QUEUE) to avoid IO stalls.  BLK_MQ_DELAY_QUEUE is
3 ms because both scsi-mq and nvmefc are using that magic value.

If a driver can make sure there is in-flight IO, it is safe to return
BLK_STS_DEV_RESOURCE because:

1) If all in-flight IOs complete before examining SCHED_RESTART in
blk_mq_dispatch_rq_list(), SCHED_RESTART must be cleared, so queue
is run immediately in this case by blk_mq_dispatch_rq_list();

2) if there is any in-flight IO after/when examining SCHED_RESTART
in blk_mq_dispatch_rq_list():
- if SCHED_RESTART isn't set, queue is run immediately as handled in 1)
- otherwise, this request will be dispatched after any in-flight IO is
  completed via blk_mq_sched_restart()

3) if SCHED_RESTART is set concurently in context because of
BLK_STS_RESOURCE, blk_mq_delay_run_hw_queue() will cover the above two
cases and make sure IO hang can be avoided.

One invariant is that queue will be rerun if SCHED_RESTART is set.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-30 20:18:28 -07:00
Linus Torvalds 168fe32a07 Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull poll annotations from Al Viro:
 "This introduces a __bitwise type for POLL### bitmap, and propagates
  the annotations through the tree. Most of that stuff is as simple as
  'make ->poll() instances return __poll_t and do the same to local
  variables used to hold the future return value'.

  Some of the obvious brainos found in process are fixed (e.g. POLLIN
  misspelled as POLL_IN). At that point the amount of sparse warnings is
  low and most of them are for genuine bugs - e.g. ->poll() instance
  deciding to return -EINVAL instead of a bitmap. I hadn't touched those
  in this series - it's large enough as it is.

  Another problem it has caught was eventpoll() ABI mess; select.c and
  eventpoll.c assumed that corresponding POLL### and EPOLL### were
  equal. That's true for some, but not all of them - EPOLL### are
  arch-independent, but POLL### are not.

  The last commit in this series separates userland POLL### values from
  the (now arch-independent) kernel-side ones, converting between them
  in the few places where they are copied to/from userland. AFAICS, this
  is the least disruptive fix preserving poll(2) ABI and making epoll()
  work on all architectures.

  As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and
  it will trigger only on what would've triggered EPOLLWRBAND on other
  architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered
  at all on sparc. With this patch they should work consistently on all
  architectures"

* 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
  make kernel-side POLL... arch-independent
  eventpoll: no need to mask the result of epi_item_poll() again
  eventpoll: constify struct epoll_event pointers
  debugging printk in sg_poll() uses %x to print POLL... bitmap
  annotate poll(2) guts
  9p: untangle ->poll() mess
  ->si_band gets POLL... bitmap stored into a user-visible long field
  ring_buffer_poll_wait() return value used as return value of ->poll()
  the rest of drivers/*: annotate ->poll() instances
  media: annotate ->poll() instances
  fs: annotate ->poll() instances
  ipc, kernel, mm: annotate ->poll() instances
  net: annotate ->poll() instances
  apparmor: annotate ->poll() instances
  tomoyo: annotate ->poll() instances
  sound: annotate ->poll() instances
  acpi: annotate ->poll() instances
  crypto: annotate ->poll() instances
  block: annotate ->poll() instances
  x86: annotate ->poll() instances
  ...
2018-01-30 17:58:07 -08:00
Linus Torvalds 0a4b6e2f80 Merge branch 'for-4.16/block' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
 "This is the main pull request for block IO related changes for the
  4.16 kernel. Nothing major in this pull request, but a good amount of
  improvements and fixes all over the map. This contains:

   - BFQ improvements, fixes, and cleanups from Angelo, Chiara, and
     Paolo.

   - Support for SMR zones for deadline and mq-deadline from Damien and
     Christoph.

   - Set of fixes for bcache by way of Michael Lyle, including fixes
     from himself, Kent, Rui, Tang, and Coly.

   - Series from Matias for lightnvm with fixes from Hans Holmberg,
     Javier, and Matias. Mostly centered around pblk, and the removing
     rrpc 1.2 in preparation for supporting 2.0.

   - A couple of NVMe pull requests from Christoph. Nothing major in
     here, just fixes and cleanups, and support for command tracing from
     Johannes.

   - Support for blk-throttle for tracking reads and writes separately.
     From Joseph Qi. A few cleanups/fixes also for blk-throttle from
     Weiping.

   - Series from Mike Snitzer that enables dm to register its queue more
     logically, something that's alwways been problematic on dm since
     it's a stacked device.

   - Series from Ming cleaning up some of the bio accessor use, in
     preparation for supporting multipage bvecs.

   - Various fixes from Ming closing up holes around queue mapping and
     quiescing.

   - BSD partition fix from Richard Narron, fixing a problem where we
     can't mount newer (10/11) FreeBSD partitions.

   - Series from Tejun reworking blk-mq timeout handling. The previous
     scheme relied on atomic bits, but it had races where we would think
     a request had timed out if it to reused at the wrong time.

   - null_blk now supports faking timeouts, to enable us to better
     exercise and test that functionality separately. From me.

   - Kill the separate atomic poll bit in the request struct. After
     this, we don't use the atomic bits on blk-mq anymore at all. From
     me.

   - sgl_alloc/free helpers from Bart.

   - Heavily contended tag case scalability improvement from me.

   - Various little fixes and cleanups from Arnd, Bart, Corentin,
     Douglas, Eryu, Goldwyn, and myself"

* 'for-4.16/block' of git://git.kernel.dk/linux-block: (186 commits)
  block: remove smart1,2.h
  nvme: add tracepoint for nvme_complete_rq
  nvme: add tracepoint for nvme_setup_cmd
  nvme-pci: introduce RECONNECTING state to mark initializing procedure
  nvme-rdma: remove redundant boolean for inline_data
  nvme: don't free uuid pointer before printing it
  nvme-pci: Suspend queues after deleting them
  bsg: use pr_debug instead of hand crafted macros
  blk-mq-debugfs: don't allow write on attributes with seq_operations set
  nvme-pci: Fix queue double allocations
  block: Set BIO_TRACE_COMPLETION on new bio during split
  blk-throttle: use queue_is_rq_based
  block: Remove kblockd_schedule_delayed_work{,_on}()
  blk-mq: Avoid that blk_mq_delay_run_hw_queue() introduces unintended delays
  blk-mq: Rename blk_mq_request_direct_issue() into blk_mq_request_issue_directly()
  lib/scatterlist: Fix chaining support in sgl_alloc_order()
  blk-throttle: track read and write request individually
  block: add bdev_read_only() checks to common helpers
  block: fail op_is_write() requests to read-only partitions
  blk-throttle: export io_serviced_recursive, io_service_bytes_recursive
  ...
2018-01-29 11:51:49 -08:00
Khazhismel Kumykov f20426056f dm mpath selector: more evenly distribute ties
Move the last used path to the end of the list (least preferred) so that
ties are more evenly distributed.

For example, in case with three paths with one that is slower than
others, the remaining two would be unevenly used if they tie. This is
due to the rotation not being a truely fair distribution.

Illustrated: paths a, b, c, 'c' has 1 outstanding IO, a and b are 'tied'
Three possible rotations:
(a, b, c) -> best path 'a'
(b, c, a) -> best path 'b'
(c, a, b) -> best path 'a'
(a, b, c) -> best path 'a'
(b, c, a) -> best path 'b'
(c, a, b) -> best path 'a'
...

So 'a' is used 2x more than 'b', although they should be used evenly.

With this change, the most recently used path is always the least
preferred, removing this bias resulting in even distribution.
(a, b, c) -> best path 'a'
(b, c, a) -> best path 'b'
(c, a, b) -> best path 'a'
(c, b, a) -> best path 'b'
...

Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-29 13:44:58 -05:00
Scott Bauer cc65661981 dm unstripe: fix target length versus number of stripes size check
Since the unstripe target takes a target length which is the
size of *one* striped member we're trying to expose, not the
total size of *all* the striped members, the check does not
make sense and fails for some striped setups.

For example, say we have a 4TB striped device:
or 3907018496 sectors per underlying device:

if (sector_div(width, uc->stripes)) :
   3907018496 / 2(num stripes)  == 1953509248

tmp_len = width;
if (sector_div(tmp_len, uc->chunk_size)) :
   1953509248 / 256(chunk size) == 7630895.5
   (fails)

Fix this by removing the first check which isn't valid for unstriping.

Signed-off-by: Scott Bauer <scott.bauer@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-29 13:44:58 -05:00
Luis de Bethencourt bd6d1e0a5f dm thin: fix trailing semicolon in __remap_and_issue_shared_cell
The trailing semicolon is an empty statement that does no operation.
Removing it since it doesn't do anything.

Signed-off-by: Luis de Bethencourt <luisbg@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-29 13:44:57 -05:00
Mike Snitzer eaa160eded dm table: fix NVMe bio-based dm_table_determine_type() validation
The 'verify_rq_based:' code in dm_table_determine_type() was checking
all devices in the DM table rather than only checking the data devices.
Fix this by using the immutable target's iterate_devices method.

Also, tweak the block of dm_table_determine_type() code that decides
whether to upgrade from DM_TYPE_BIO_BASED to DM_TYPE_NVME_BIO_BASED so
that it makes sure the immutable_target doesn't support require
splitting IOs.

These changes have been verified to allow a "thin-pool" target whose
data device is an NVMe device to be upgraded to DM_TYPE_NVME_BIO_BASED.
Using the thin-pool in NVMe bio-based mode was verified to pass all the
device-mapper-test-suite's "thin-provisioning" tests.

Also verified that request-based DM multipath (with queue_mode "rq" and
"mq") works as expected using the 'mptest' harness.

Fixes: 22c11858e ("dm: introduce DM_TYPE_NVME_BIO_BASED")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-29 13:44:56 -05:00
Mike Snitzer c12c9a3c38 dm: various cleanups to md->queue initialization code
Also, add dm_sysfs_init() error handling to dm_create().

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-29 13:44:55 -05:00
Mike Snitzer ac514ffc96 dm mpath: delay the retry of a request if the target responded as busy
Add DM_ENDIO_DELAY_REQUEUE to allow request-based multipath's
multipath_end_io() to instruct dm-rq.c:dm_done() to delay a requeue.
This is beneficial to do if BLK_STS_RESOURCE is returned from the target
(because target is busy).

Relative to blk-mq: kick the hw queues via blk_mq_requeue_work(),
indirectly from dm-rq.c:__dm_mq_kick_requeue_list(), after a delay.

For old .request_fn: use blk_delay_queue().

bio-based multipath doesn't have feature parity with request-based for
retryable error requeues; that is something that'll need fixing in the
future.

Suggested-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Bart Van Assche <bart.vanassche@wdc.com>
[as interpreted from Bart's "... patch looks fine to me."]
2018-01-29 13:44:54 -05:00
Ming Lei 396eaf21ee blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback
blk_insert_cloned_request() is called in the fast path of a dm-rq driver
(e.g. blk-mq request-based DM mpath).  blk_insert_cloned_request() uses
blk_mq_request_bypass_insert() to directly append the request to the
blk-mq hctx->dispatch_list of the underlying queue.

1) This way isn't efficient enough because the hctx spinlock is always
used.

2) With blk_insert_cloned_request(), we completely bypass underlying
queue's elevator and depend on the upper-level dm-rq driver's elevator
to schedule IO.  But dm-rq currently can't get the underlying queue's
dispatch feedback at all.  Without knowing whether a request was issued
or not (e.g. due to underlying queue being busy) the dm-rq elevator will
not be able to provide effective IO merging (as a side-effect of dm-rq
currently blindly destaging a request from its elevator only to requeue
it after a delay, which kills any opportunity for merging).  This
obviously causes very bad sequential IO performance.

Fix this by updating blk_insert_cloned_request() to use
blk_mq_request_direct_issue().  blk_mq_request_direct_issue() allows a
request to be issued directly to the underlying queue and returns the
dispatch feedback (blk_status_t).  If blk_mq_request_direct_issue()
returns BLK_SYS_RESOURCE the dm-rq driver will now use DM_MAPIO_REQUEUE
to _not_ destage the request.  Whereby preserving the opportunity to
merge IO.

With this, request-based DM's blk-mq sequential IO performance is vastly
improved (as much as 3X in mpath/virtio-scsi testing).

Signed-off-by: Ming Lei <ming.lei@redhat.com>
[blk-mq.c changes heavily influenced by Ming Lei's initial solution, but
they were refactored to make them less fragile and easier to read/review]
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-17 09:46:54 -07:00
Ming Lei 459b54019c dm mpath: return DM_MAPIO_DELAY_REQUEUE if QUEUE_IO or PG_INIT_REQUIRED
Avoid using DM_MAPIO_REQUEUE unless absolutely necessary because it
results in dm-rq.c:dm_mq_queue_rq() returning BLK_STS_RESOURCE to
blk-mq -- doing so should only ever be done if the underlying queue is
out of resources.  So switch to returning DM_MAPIO_DELAY_REQUEUE from
multipath_clone_and_map() if either MPATHF_QUEUE_IO or
MPATHF_PG_INIT_REQUIRED are set.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:16:18 -05:00
Ming Lei 050af08ffb dm mpath: return DM_MAPIO_REQUEUE on blk-mq rq allocation failure
blk-mq will rerun queue via RESTART or dispatch wake after one request
is completed, so not necessary to wait random time for requeuing, we
should trust blk-mq to do it.

More importantly, we need to return BLK_STS_RESOURCE to blk-mq so that
dequeuing from the I/O scheduler can be stopped, this results in
improved I/O merging.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:16:17 -05:00
Ma Shimiao 4b259fc4a8 dm log writes: fix max length used for kstrndup
If source string is longer than max, kstrndup will allocate max+1
space.  So make sure the result will not exceed max.

Signed-off-by: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:16:16 -05:00
Mike Snitzer d5ffebdd79 dm: backfill missing calls to mutex_destroy()
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:16:15 -05:00
Mikulas Patocka ae1093be5a dm snapshot: use mutex instead of rw_semaphore
The rw_semaphore is acquired for read only in two places, neither is
performance-critical.  So replace it with a mutex -- which is more
efficient.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:16:14 -05:00
Goldwyn Rodrigues 7690e25302 dm flakey: check for null arg_name in parse_features()
One can crash dm-flakey by specifying more feature arguments than the
number of features supplied.  Checking for null in arg_name avoids
this.

dmsetup create flakey-test --table "0 66076080 flakey /dev/sdb9 0 0 180 2 drop_writes"

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:16:13 -05:00
Brian Norris f6e7baadd9 dm: move dm_table_destroy() to same header as dm_table_create()
If anyone is going to use dm_table_create(), they probably should be
able to use dm_table_destroy() too. Move the dm_table_destroy()
definition outside the private header, near dm_table_create()

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:16:06 -05:00
Wei Yongjun 67ac901c55 dm raid: make raid_sets symbol static
Fixes the following sparse warning:

drivers/md/dm-raid.c:33:1: warning:
 symbol 'raid_sets' was not declared. Should it be static?

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:16:05 -05:00
Mike Snitzer 0e696d385d dm bufio: eliminate unnecessary labels in dm_bufio_client_create()
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:16:04 -05:00
Aliaksei Karaliou 46898e9a7a dm bufio: check result of register_shrinker()
dm_bufio_client_create() does not check result of register_shrinker()
which was tagged as __must_check recently, reported by sparse.

Signed-off-by: Aliaksei Karaliou <akaraliou.dev@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:16:03 -05:00
Aliaksei Karaliou bde1418478 dm bufio: add missed destroys of client mutex
The client's mutex needs to be destroyed in dm_bufio_client_destroy() as
well as the dm_bufio_client_create() error path.

Signed-off-by: Aliaksei Karaliou <akaraliou.dev@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:16:02 -05:00
Mikulas Patocka 905be0a121 dm bufio: use REQ_OP_READ and REQ_OP_WRITE
Use REQ_OP_READ and REQ_OP_WRITE macros instead of READ and WRITE.  They
have the same value, but the block layer uses REQ_OP so bufio should
too.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:16:01 -05:00
Scott Bauer 18a5bf2705 dm: add unstriped target
This device mapper "unstriped" target remaps and unstripes I/O so it
is issued solely on a single drive in a HW RAID0 or dm-striped target.

In a 4 drive HW RAID0 the striped target exposes 1/4th of the LBA range
as a virtual drive.  Each I/O to that virtual drive will only be issued
to the 1 drive that was selected of the 4 drives in the HW RAID0.

This unstriped target is most useful for Intel NVMe drives that have
multiple cores but that do not have firmware control to pin separate LBA
ranges to each discrete cpu core.

Signed-off-by: Scott Bauer <scott.bauer@intel.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:16:00 -05:00
Wei Yongjun 3cc2e57c4b dm crypt: fix error return code in crypt_ctr()
Fix to return error code -ENOMEM from the mempool_create_kmalloc_pool()
error handling case instead of 0, as done elsewhere in this function.

Fixes: ef43aa3806 ("dm crypt: add cryptographic data integrity protection (authenticated encryption)")
Cc: stable@vger.kernel.org # 4.12+
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:10:55 -05:00
Ondrej Kozina dc94902bde dm crypt: wipe kernel key copy after IV initialization
Loading key via kernel keyring service erases the internal
key copy immediately after we pass it in crypto layer. This is
wrong because IV is initialized later and we use wrong key
for the initialization (instead of real key there's just zeroed
block).

The bug may cause data corruption if key is loaded via kernel keyring
service first and later same crypt device is reactivated using exactly
same key in hexbyte representation, or vice versa. The bug (and fix)
affects only ciphers using following IVs: essiv, lmk and tcw.

Fixes: c538f6ec9f ("dm crypt: add ability to use keys from the kernel key retention service")
Cc: stable@vger.kernel.org # 4.10+
Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Reviewed-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:10:48 -05:00
Mikulas Patocka 717f4b1c52 dm integrity: don't store cipher request on the stack
Some asynchronous cipher implementations may use DMA.  The stack may
be mapped in the vmalloc area that doesn't support DMA.  Therefore,
the cipher request and initialization vector shouldn't be on the
stack.

Fix this by allocating the request and iv with kmalloc.

Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:08:57 -05:00
Milan Broz 27c7003697 dm crypt: fix crash by adding missing check for auth key size
If dm-crypt uses authenticated mode with separate MAC, there are two
concatenated part of the key structure - key(s) for encryption and
authentication key.

Add a missing check for authenticated key length.  If this key length is
smaller than actually provided key, dm-crypt now properly fails instead
of crashing.

Fixes: ef43aa3806 ("dm crypt: add cryptographic data integrity protection (authenticated encryption)")
Cc: stable@vger.kernel.org # 4.12+
Reported-by: Salah Coronya <salahx@yahoo.com>
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:08:41 -05:00
Joe Thornber bc68d0a435 dm btree: fix serious bug in btree_split_beneath()
When inserting a new key/value pair into a btree we walk down the spine of
btree nodes performing the following 2 operations:

  i) space for a new entry
  ii) adjusting the first key entry if the new key is lower than any in the node.

If the _root_ node is full, the function btree_split_beneath() allocates 2 new
nodes, and redistibutes the root nodes entries between them.  The root node is
left with 2 entries corresponding to the 2 new nodes.

btree_split_beneath() then adjusts the spine to point to one of the two new
children.  This means the first key is never adjusted if the new key was lower,
ie. operation (ii) gets missed out.  This can result in the new key being
'lost' for a period; until another low valued key is inserted that will uncover
it.

This is a serious bug, and quite hard to make trigger in normal use.  A
reproducing test case ("thin create devices-in-reverse-order") is
available as part of the thin-provision-tools project:
  https://github.com/jthornber/thin-provisioning-tools/blob/master/functional-tests/device-mapper/dm-tests.scm#L593

Fix the issue by changing btree_split_beneath() so it no longer adjusts
the spine.  Instead it unlocks both the new nodes, and lets the main
loop in btree_insert_raw() relock the appropriate one and make any
neccessary adjustments.

Cc: stable@vger.kernel.org
Reported-by: Monty Pavel <monty_pavel@sina.com>
Signed-off-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:07:55 -05:00
Dennis Yang 490ae017f5 dm thin metadata: THIN_MAX_CONCURRENT_LOCKS should be 6
For btree removal, there is a corner case that a single thread
could takes 6 locks which is more than THIN_MAX_CONCURRENT_LOCKS(5)
and leads to deadlock.

A btree removal might eventually call
rebalance_children()->rebalance3() to rebalance entries of three
neighbor child nodes when shadow_spine has already acquired two
write locks. In rebalance3(), it tries to shadow and acquire the
write locks of all three child nodes. However, shadowing a child
node requires acquiring a read lock of the original child node and
a write lock of the new block. Although the read lock will be
released after block shadowing, shadowing the third child node
in rebalance3() could still take the sixth lock.
(2 write locks for shadow_spine +
 2 write locks for the first two child nodes's shadow +
 1 write lock for the last child node's shadow +
 1 read lock for the last child node)

Cc: stable@vger.kernel.org
Signed-off-by: Dennis Yang <dennisyang@qnap.com>
Acked-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17 09:07:54 -05:00
Tomasz Majchrzak 1532d9e87e raid5-ppl: PPL support for disks with write-back cache enabled
In order to provide data consistency with PPL for disks with write-back
cache enabled all data has to be flushed to disks before next PPL
entry. The disks to be flushed are marked in the bitmap. It's modified
under a mutex and it's only read after PPL io unit is submitted.

A limitation of 64 disks in the array has been introduced to keep data
structures and implementation simple. RAID5 arrays with so many disks are
not likely due to high risk of multiple disks failure. Such restriction
should not be a real life limitation.

With write-back cache disabled next PPL entry is submitted when data write
for current one completes. Data flush defers next log submission so trigger
it when there are no stripes for handling found.

As PPL assures all data is flushed to disk at request completion, just
acknowledge flush request when PPL is enabled.

Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Signed-off-by: Shaohua Li <sh.li@alibaba-inc.com>
2018-01-15 14:29:42 -08:00
Mike Snitzer c100ec49fd dm: fix incomplete request_queue initialization
DM is no longer prone to having its request_queue be improperly
initialized.

Summary of changes:

- defer DM's blk_register_queue() from add_disk()-time until
  dm_setup_md_queue() by using add_disk_no_queue_reg() in alloc_dev().

- dm_setup_md_queue() is updated to fully initialize DM's request_queue
  (_after_ all table loads have occurred and the request_queue's type,
  features and limits are known).

A very welcome side-effect of these changes is DM no longer needs to:
1) backfill the "mq" sysfs entry (because historically DM didn't
initialize the request_queue to use blk-mq until _after_
blk_register_queue() was called via add_disk()).
2) call elv_register_queue() to get .request_fn request-based DM
device's "iosched" exposed in syfs.

In addition, blk-mq debugfs support is now made available because
request-based DM's blk-mq request_queue is now properly initialized
before dm_setup_md_queue() calls blk_register_queue().

These changes also stave off the need to introduce new DM-specific
workarounds in block core, e.g. this proposal:
https://patchwork.kernel.org/patch/10067961/

In the end DM devices should be less unicorn in nature (relative to
initialization and availability of block core infrastructure provided by
the request_queue).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-15 08:54:32 -07:00
Keith Busch a1275677f8 dm mpath: Use blk_path_error
Uses common code for determining if an error should be retried on
alternate path.

Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-10 10:52:20 -07:00
Michael Lyle 3609c471a1 bcache: closures: move control bits one bit right
Otherwise, architectures that do negated adds of atomics (e.g. s390)
to do atomic_sub fail in closure_set_stopped.

Signed-off-by: Michael Lyle <mlyle@lyle.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-09 12:18:51 -07:00
Michael Lyle 616486ab52 bcache: fix writeback target calc on large devices
Bcache needs to scale the dirty data in the cache over the multiple
backing disks in order to calculate writeback rates for each.
The previous code did this by multiplying the target number of dirty
sectors by the backing device size, and expected it to fit into a
uint64_t; this blows up on relatively small backing devices.

The new approach figures out the bdev's share in 16384ths of the overall
cached data.  This is chosen to cope well when bdevs drastically vary in
size and to ensure that bcache can cross the petabyte boundary for each
backing device.

This has been improved based on Tang Junhui's feedback to ensure that
every device gets a share of dirty data, no matter how small it is
compared to the total backing pool.

The existing mechanism is very limited; this is purely a bug fix to
remove limits on volume size.  However, there still needs to be change
to make this "fair" over many volumes where some are idle.

Reported-by: Jack Douglas <jack@douglastechnology.co.uk>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08 13:29:00 -07:00
Coly Li 5138ac6748 bcache: fix misleading error message in bch_count_io_errors()
Bcache only does recoverable I/O for read operations by calling
cached_dev_read_error(). For write opertions there is no I/O recovery for
failed requests.

But in bch_count_io_errors() no matter read or write I/Os, before errors
counter reaches io error limit, pr_err() always prints "IO error on %,
recoverying". For write requests this information is misleading, because
there is no I/O recovery at all.

This patch adds a parameter 'is_read' to bch_count_io_errors(), and only
prints "recovering" by pr_err() when the bio direction is READ.

Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08 13:29:00 -07:00
Coly Li 2831231d4c bcache: reduce cache_set devices iteration by devices_max_used
Member devices of struct cache_set is used to reference all attached
bcache devices to this cache set. If it is treated as array of pointers,
size of devices[] is indicated by member nr_uuids of struct cache_set.

nr_uuids is calculated in drivers/md/super.c:bch_cache_set_alloc(),
	bucket_bytes(c) / sizeof(struct uuid_entry)
Bucket size is determined by user space tool "make-bcache", by default it
is 1024 sectors (defined in bcache-tools/make-bcache.c:main()). So default
nr_uuids value is 4096 from the above calculation.

Every time when bcache code iterates bcache devices of a cache set, all
the 4096 pointers are checked even only 1 bcache device is attached to the
cache set, that's a wast of time and unncessary.

This patch adds a member devices_max_used to struct cache_set. Its value
is 1 + the maximum used index of devices[] in a cache set. When iterating
all valid bcache devices of a cache set, use c->devices_max_used in
for-loop may reduce a lot of useless checking.

Personally, my motivation of this patch is not for performance, I use it
in bcache debugging, which helps me to narrow down the scape to check
valid bcached devices of a cache set.

Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08 13:29:00 -07:00
Zhai Zhaoxuan b40503ea4f bcache: fix unmatched generic_end_io_acct() & generic_start_io_acct()
The function cached_dev_make_request() and flash_dev_make_request() call
generic_start_io_acct() with (struct bcache_device)->disk when they start a
closure. Then the function bio_complete() calls generic_end_io_acct() with
(struct search)->orig_bio->bi_disk when the closure has done.
Since the `bi_disk` is not the bcache device, the generic_end_io_acct() is
called with a wrong device queue.

It causes the "inflight" (in struct hd_struct) counter keep increasing
without decreasing.

This patch fix the problem by calling generic_end_io_acct() with
(struct bcache_device)->disk.

Signed-off-by: Zhai Zhaoxuan <kxuanobj@gmail.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Coly Li <colyli@suse.de>
Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08 13:29:00 -07:00
Kent Overstreet ce439bf78b bcache: mark closure_sync() __sched
[edit by mlyle: include sched/debug.h to get __sched]

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08 13:29:00 -07:00
Kent Overstreet e4bf791937 bcache: Fix, improve efficiency of closure_sync()
Eliminates cases where sync can race and fail to complete / get stuck.
Removes many status flags and simplifies entering-and-exiting closure
sleeping behaviors.

[mlyle: fixed conflicts due to changed return behavior in mainline.
extended commit comment, and squashed down two commits that were mostly
contradictory to get to this state.  Changed __set_current_state to
set_current_state per Jens review comment]

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08 13:29:00 -07:00
Michael Lyle b1092c9af9 bcache: allow quick writeback when backing idle
If the control system would wait for at least half a second, and there's
been no reqs hitting the backing disk for awhile: use an alternate mode
where we have at most one contiguous set of writebacks in flight at a
time. (But don't otherwise delay).  If front-end IO appears, it will
still be quick, as it will only have to contend with one real operation
in flight.  But otherwise, we'll be sending data to the backing disk as
quickly as it can accept it (with one op at a time).

Signed-off-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08 13:29:00 -07:00
Michael Lyle 6e6ccc67b9 bcache: writeback: properly order backing device IO
Writeback keys are presently iterated and dispatched for writeback in
order of the logical block address on the backing device.  Multiple may
be, in parallel, read from the cache device and then written back
(especially when there are contiguous I/O).

However-- there was no guarantee with the existing code that the writes
would be issued in LBA order, as the reads from the cache device are
often re-ordered.  In turn, when writing back quickly, the backing disk
often has to seek backwards-- this slows writeback and increases
utilization.

This patch introduces an ordering mechanism that guarantees that the
original order of issue is maintained for the write portion of the I/O.
Performance for writeback is significantly improved when there are
multiple contiguous keys or high writeback rates.

Signed-off-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn>
Tested-by: Tang Junhui <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08 13:29:00 -07:00
Tang Junhui 539d39eb27 bcache: fix wrong return value in bch_debug_init()
in bch_debug_init(), ret is always 0, and the return value is useless,
change it to return 0 if be success after calling debugfs_create_dir(),
else return a non-zero value.

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08 13:29:00 -07:00
Tang Junhui 4eca1cb28d bcache: segregate flash only volume write streams
In such scenario that there are some flash only volumes
, and some cached devices, when many tasks request these devices in
writeback mode, the write IOs may fall to the same bucket as bellow:
| cached data | flash data | cached data | cached data| flash data|
then after writeback of these cached devices, the bucket would
be like bellow bucket:
| free | flash data | free | free | flash data |

So, there are many free space in this bucket, but since data of flash
only volumes still exists, so this bucket cannot be reclaimable,
which would cause waste of bucket space.

In this patch, we segregate flash only volume write streams from
cached devices, so data from flash only volumes and cached devices
can store in different buckets.

Compare to v1 patch, this patch do not add a additionally open bucket
list, and it is try best to segregate flash only volume write streams
from cached devices, sectors of flash only volumes may still be mixed
with dirty sectors of cached device, but the number is very small.

[mlyle: fixed commit log formatting, permissions, line endings]

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08 13:29:00 -07:00
Vasyl Gomonovych 9d13411784 bcache: Use PTR_ERR_OR_ZERO()
Fix ptr_ret.cocci warnings:
drivers/md/bcache/btree.c:1800:1-3: WARNING: PTR_ERR_OR_ZERO can be used

Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR

Generated by: scripts/coccinelle/api/ptr_ret.cocci

Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08 13:29:00 -07:00
Tang Junhui 8d29c4426b bcache: stop writeback thread after detaching
Currently, when a cached device detaching from cache, writeback thread is
not stopped, and writeback_rate_update work is not canceled. For example,
after the following command:
echo 1 >/sys/block/sdb/bcache/detach
you can still see the writeback thread. Then you attach the device to the
cache again, bcache will create another writeback thread, for example,
after below command:
echo  ba0fb5cd-658a-4533-9806-6ce166d883b9 > /sys/block/sdb/bcache/attach
then you will see 2 writeback threads.
This patch stops writeback thread and cancels writeback_rate_update work
when cached device detaching from cache.

Compare with patch v1, this v2 patch moves code down into the register
lock for safety in case of any future changes as Coly and Mike suggested.

[edit by mlyle: commit log spelling/formatting]

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08 13:29:00 -07:00
Rui Hua b221fc130c bcache: ret IOERR when read meets metadata error
The read request might meet error when searching the btree, but the error
was not handled in cache_lookup(), and this kind of metadata failure will
not go into cached_dev_read_error(), finally, the upper layer will receive
bi_status=0.  In this patch we judge the metadata error by the return
value of bch_btree_map_keys(), there are two potential paths give rise to
the error:

1. Because the btree is not totally cached in memery, we maybe get error
   when read btree node from cache device (see bch_btree_node_get()), the
   likely errno is -EIO, -ENOMEM

2. When read miss happens, bch_btree_insert_check_key() will be called to
   insert a "replace_key" to btree(see cached_dev_cache_miss(), just for
   doing preparatory work before insert the missed data to cache device),
   a failure can also happen in this situation, the likely errno is
   -ENOMEM

bch_btree_map_keys() will return MAP_DONE in normal scenario, but we will
get either -EIO or -ENOMEM in above two cases. if this happened, we should
NOT recover data from backing device (when cache device is dirty) because
we don't know whether bkeys the read request covered are all clean.  And
after that happened, s->iop.status is still its initially value(0) before
we submit s->bio.bio, we set it to BLK_STS_IOERR, so it can go into
cached_dev_read_error(), and finally it can be passed to upper layer, or
recovered by reread from backing device.

[edit by mlyle: patch formatting, word-wrap, comment spelling,
commit log format]

Signed-off-by: Hua Rui <huarui.dev@gmail.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-08 13:29:00 -07:00
Mike Snitzer 0001ec565d dm mpath: factor out SCSI vs NVMe path selection
Trying to do both SCSI and NVMe bio-based handling with branching in the
same common code has proven too tedious on a code maintenance level.  In
addition it slightly hurts IO performance.

Fix this by factoring out __map_bio() and __map_bio_nvme().

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-06 11:23:28 -05:00