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2019-01-09block: fix kerneldoc comment for blk_attempt_plug_merge()Jonathan Corbet1-1/+0
Commit 5f0ed774ed29 ("block: sum requests in the plug structure") removed the request_count parameter from block_attempt_plug_merge(), but did not remove the associated kerneldoc comment, introducing this warning to the docs build: ./block/blk-core.c:685: warning: Excess function parameter 'request_count' description in 'blk_attempt_plug_merge' Remove the obsolete description and make things a little quieter. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-01-08block: clarify documentation for blk_{start|finish}_plugJeff Moyer1-0/+19
There was some confusion about what these functions did. Make it clear that this is a hint for upper layers to pass to the block layer, and that it does not guarantee that I/O will not be submitted between a start and finish plug. Reported-by: "Darrick J. Wong" <darrick.wong@oracle.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-01-02Merge tag 'for-4.21/block-20190102' of git://git.kernel.dk/linux-blockLinus Torvalds3-23/+8
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 ...
2018-12-29Merge tag 'kconfig-v4.21' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kconfig updates from Masahiro Yamada: - support -y option for merge_config.sh to avoid downgrading =y to =m - remove S_OTHER symbol type, and touch include/config/*.h files correctly - fix file name and line number in lexer warnings - fix memory leak when EOF is encountered in quotation - resolve all shift/reduce conflicts of the parser - warn no new line at end of file - make 'source' statement more strict to take only string literal - rewrite the lexer and remove the keyword lookup table - convert to SPDX License Identifier - compile C files independently instead of including them from zconf.y - fix various warnings of gconfig - misc cleanups * tag 'kconfig-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits) kconfig: surround dbg_sym_flags with #ifdef DEBUG to fix gconf warning kconfig: split images.c out of qconf.cc/gconf.c to fix gconf warnings kconfig: add static qualifiers to fix gconf warnings kconfig: split the lexer out of zconf.y kconfig: split some C files out of zconf.y kconfig: convert to SPDX License Identifier kconfig: remove keyword lookup table entirely kconfig: update current_pos in the second lexer kconfig: switch to ASSIGN_VAL state in the second lexer kconfig: stop associating kconf_id with yylval kconfig: refactor end token rules kconfig: stop supporting '.' and '/' in unquoted words treewide: surround Kconfig file paths with double quotes microblaze: surround string default in Kconfig with double quotes kconfig: use T_WORD instead of T_VARIABLE for variables kconfig: use specific tokens instead of T_ASSIGN for assignments kconfig: refactor scanning and parsing "option" properties kconfig: use distinct tokens for type and default properties kconfig: remove redundant token defines kconfig: rename depends_list to comment_option_list ...
2018-12-28Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds3-18/+8
Pull SCSI updates from James Bottomley: "This is mostly update of the usual drivers: smarpqi, lpfc, qedi, megaraid_sas, libsas, zfcp, mpt3sas, hisi_sas. Additionally, we have a pile of annotation, unused variable and minor updates. The big API change is the updates for Christoph's DMA rework which include removing the DISABLE_CLUSTERING flag. And finally there are a couple of target tree updates" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (259 commits) scsi: isci: request: mark expected switch fall-through scsi: isci: remote_node_context: mark expected switch fall-throughs scsi: isci: remote_device: Mark expected switch fall-throughs scsi: isci: phy: Mark expected switch fall-through scsi: iscsi: Capture iscsi debug messages using tracepoints scsi: myrb: Mark expected switch fall-throughs scsi: megaraid: fix out-of-bound array accesses scsi: mpt3sas: mpt3sas_scsih: Mark expected switch fall-through scsi: fcoe: remove set but not used variable 'port' scsi: smartpqi: call pqi_free_interrupts() in pqi_shutdown() scsi: smartpqi: fix build warnings scsi: smartpqi: update driver version scsi: smartpqi: add ofa support scsi: smartpqi: increase fw status register read timeout scsi: smartpqi: bump driver version scsi: smartpqi: add smp_utils support scsi: smartpqi: correct lun reset issues scsi: smartpqi: correct volume status scsi: smartpqi: do not offline disks for transient did no connect conditions scsi: smartpqi: allow for larger raid maps ...
2018-12-28Merge tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-blockLinus Torvalds52-10182/+1813
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 ...
2018-12-21bsg: deprecate BIDI support in bsgChristoph Hellwig1-0/+4
Besides the OSD command set that never got traction, the only SCSI command using bidirectional buffers is XDWRITEREAD in the 10 and 32 byte variants, which is extremely esoteric and has been removed from the spec again as of SBC4r15. It probably doesn't make sense to keep the support code around just for that, so start deprecating the support. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-21blkcg: remove unused __blkg_release_rcu()Dennis Zhou1-23/+0
An earlier commit 7fcf2b033b84 ("blkcg: change blkg reference counting to use percpu_ref") moved around the release call from blkg_put() to be a part of the percpu_ref cleanup. Remove the additional unused code which should have been removed earlier. Signed-off-by: Dennis Zhou <dennis@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-21blkcg: clean up blkg_tryget_closest()Dennis Zhou1-0/+4
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>
2018-12-22treewide: surround Kconfig file paths with double quotesMasahiro Yamada1-1/+1
The Kconfig lexer supports special characters such as '.' and '/' in the parameter context. In my understanding, the reason is just to support bare file paths in the source statement. I do not see a good reason to complicate Kconfig for the room of ambiguity. The majority of code already surrounds file paths with double quotes, and it makes sense since file paths are constant string literals. Make it treewide consistent now. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Ingo Molnar <mingo@kernel.org>
2018-12-20kyber: use sbitmap add_wait_queue/list_del wait helpersJens Axboe1-13/+15
sbq_wake_ptr() checks sbq->ws_active to know if it needs to loop the wait indexes or not. This requires the use of the sbitmap waitqueue wrappers, but kyber doesn't use those for its domain token waitqueue handling. Convert kyber to use the helpers. This fixes a hang with waiting for domain tokens. Fixes: 5d2ee7122c73 ("sbitmap: optimize wakeup check") Tested-by: Ming Lei <ming.lei@redhat.com> Reported-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-19block: save irq state in blkg_lookup_create()Ming Lei1-2/+4
blkg_lookup_create() may be called from pool_map() in which irq state is saved, so we have to do that in blkg_lookup_create(). Otherwise, the following lockdep warning can be triggered: [ 104.258537] ================================ [ 104.259129] WARNING: inconsistent lock state [ 104.259725] 4.20.0-rc6+ #545 Not tainted [ 104.260268] -------------------------------- [ 104.260865] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. [ 104.261727] swapper/49/0 [HC0[0]:SC1[1]:HE0:SE0] takes: [ 104.262444] 00000000db365b5d (&(&pool->lock)->rlock#3){+.?.}, at: thin_endio+0xcf/0x2a3 [dm_thin_pool] [ 104.263747] {SOFTIRQ-ON-W} state was registered at: [ 104.264417] _raw_spin_unlock_irq+0x29/0x4c [ 104.265014] blkg_lookup_create+0xdc/0xe6 [ 104.265609] bio_associate_blkg_from_css+0xd3/0x13f [ 104.266312] bio_associate_blkg+0x15a/0x1bb [ 104.266913] pool_map+0xe8/0x103 [dm_thin_pool] [ 104.267572] __map_bio+0x98/0x29c [dm_mod] [ 104.268162] __split_and_process_non_flush+0x29e/0x306 [dm_mod] [ 104.269003] __split_and_process_bio+0x16a/0x25b [dm_mod] [ 104.269971] __dm_make_request.isra.14+0xdc/0x124 [dm_mod] [ 104.270973] generic_make_request+0x3f5/0x68b [ 104.271676] process_prepared_mapping+0x166/0x1ef [dm_thin_pool] [ 104.272531] schedule_zero+0x239/0x273 [dm_thin_pool] [ 104.273245] process_cell+0x60c/0x6f1 [dm_thin_pool] [ 104.273967] do_worker+0x60c/0xca8 [dm_thin_pool] [ 104.274635] process_one_work+0x4eb/0x834 [ 104.275203] worker_thread+0x318/0x484 [ 104.275740] kthread+0x1d1/0x1e1 [ 104.276203] ret_from_fork+0x3a/0x50 [ 104.276714] irq event stamp: 170003 [ 104.277201] hardirqs last enabled at (170002): [<ffffffff81bcc33e>] _raw_spin_unlock_irqrestore+0x44/0x6b [ 104.278535] hardirqs last disabled at (170003): [<ffffffff81bcc1ad>] _raw_spin_lock_irqsave+0x20/0x55 [ 104.280273] softirqs last enabled at (169978): [<ffffffff810d13d4>] irq_enter+0x4c/0x73 [ 104.281617] softirqs last disabled at (169979): [<ffffffff810d1479>] irq_exit+0x7e/0x11d [ 104.282744] [ 104.282744] other info that might help us debug this: [ 104.283640] Possible unsafe locking scenario: [ 104.283640] [ 104.284452] CPU0 [ 104.284803] ---- [ 104.285150] lock(&(&pool->lock)->rlock#3); [ 104.285762] <Interrupt> [ 104.286130] lock(&(&pool->lock)->rlock#3); [ 104.286750] [ 104.286750] *** DEADLOCK *** [ 104.286750] [ 104.287564] no locks held by swapper/49/0. [ 104.288129] [ 104.288129] stack backtrace: [ 104.288738] CPU: 49 PID: 0 Comm: swapper/49 Not tainted 4.20.0-rc6+ #545 [ 104.289700] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-2.fc27 04/01/2014 [ 104.290858] Call Trace: [ 104.291204] <IRQ> [ 104.291502] dump_stack+0x9a/0xe6 [ 104.291968] mark_lock+0x56c/0x7a6 [ 104.292442] ? check_usage_backwards+0x209/0x209 [ 104.293086] __lock_acquire+0x400/0x15bf [ 104.293662] ? check_chain_key+0x150/0x1aa [ 104.294236] lock_acquire+0x1a6/0x1e3 [ 104.294768] ? thin_endio+0xcf/0x2a3 [dm_thin_pool] [ 104.295444] ? _raw_spin_unlock_irqrestore+0x44/0x6b [ 104.296143] ? process_prepared_discard_fail+0x36/0x36 [dm_thin_pool] [ 104.297031] _raw_spin_lock_irqsave+0x46/0x55 [ 104.297659] ? thin_endio+0xcf/0x2a3 [dm_thin_pool] [ 104.298335] thin_endio+0xcf/0x2a3 [dm_thin_pool] [ 104.298997] ? process_prepared_discard_fail+0x36/0x36 [dm_thin_pool] [ 104.299886] ? check_flags+0x20a/0x20a [ 104.300408] ? lock_acquire+0x1a6/0x1e3 [ 104.300954] ? process_prepared_discard_fail+0x36/0x36 [dm_thin_pool] [ 104.301865] clone_endio+0x1bb/0x22d [dm_mod] [ 104.302491] ? disable_write_zeroes+0x20/0x20 [dm_mod] [ 104.303200] ? bio_disassociate_blkg+0xc6/0x15f [ 104.303836] ? bio_endio+0x2b2/0x2da [ 104.304349] clone_endio+0x1f3/0x22d [dm_mod] [ 104.304978] ? disable_write_zeroes+0x20/0x20 [dm_mod] [ 104.305709] ? bio_disassociate_blkg+0xc6/0x15f [ 104.306333] ? bio_endio+0x2b2/0x2da [ 104.306853] clone_endio+0x1f3/0x22d [dm_mod] [ 104.307476] ? disable_write_zeroes+0x20/0x20 [dm_mod] [ 104.308185] ? bio_disassociate_blkg+0xc6/0x15f [ 104.308817] ? bio_endio+0x2b2/0x2da [ 104.309319] blk_update_request+0x2de/0x4cc [ 104.309927] blk_mq_end_request+0x2a/0x183 [ 104.310498] blk_done_softirq+0x16a/0x1a6 [ 104.311051] ? blk_softirq_cpu_dead+0xe2/0xe2 [ 104.311653] ? __lock_is_held+0x2a/0x87 [ 104.312186] __do_softirq+0x250/0x4e8 [ 104.312705] irq_exit+0x7e/0x11d [ 104.313157] call_function_single_interrupt+0xf/0x20 [ 104.313860] </IRQ> [ 104.314163] RIP: 0010:native_safe_halt+0x2/0x3 [ 104.314792] Code: 63 02 df f0 83 44 24 fc 00 48 89 df e8 cc 3f 7a ff 48 8b 03 a8 08 74 0b 65 81 25 9d 31 45 7e ff ff ff 7f 5b 5d 41 5c c3 fb f4 <c3> f4 c3 0f 1f 44 00 00 41 56 41 55 41 54 55 53 e8 a2 0d 5c ff e8 [ 104.317339] RSP: 0018:ffff888106c9fdc0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff04 [ 104.318390] RAX: 1ffff11020d92100 RBX: 0000000000000000 RCX: ffffffff81159ac7 [ 104.319366] RDX: 1ffffffff05d5e69 RSI: 0000000000000007 RDI: ffff888106c90d1c [ 104.320339] RBP: 0000000000000000 R08: dffffc0000000000 R09: 0000000000000001 [ 104.321313] R10: ffffed1025d57ba0 R11: ffffed1025d57b9f R12: 1ffff11020d93fbf [ 104.322328] R13: 0000000000000031 R14: ffff888106c90040 R15: 0000000000000000 [ 104.323307] ? lockdep_hardirqs_on+0x26b/0x278 [ 104.323927] default_idle+0xd9/0x1a8 [ 104.324427] do_idle+0x162/0x2b2 [ 104.324891] ? arch_cpu_idle_exit+0x28/0x28 [ 104.325467] ? mark_held_locks+0x28/0x7f [ 104.326031] ? _raw_spin_unlock_irqrestore+0x44/0x6b [ 104.326719] cpu_startup_entry+0x1d/0x1f [ 104.327261] start_secondary+0x2cb/0x308 [ 104.327806] ? set_cpu_sibling_map+0x8a3/0x8a3 [ 104.328421] secondary_startup_64+0xa4/0xb0 Fixes: b978962ad4f7f9 ("blkcg: update blkg_lookup_create() to do locking") Cc: Mike Snitzer <snitzer@redhat.com> Cc: Dennis Zhou <dennis@kernel.org> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-18scsi: block: remove the cluster flagChristoph Hellwig3-18/+8
Now that the the SCSI layer replaced the use of the cluster flag with segment size limits and the DMA boundary we can remove the cluster flag from the block layer. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-18block: make request_to_qc_t publicSagi Grimberg1-8/+0
block consumers will need it for polling requests that are sent with blk_execute_rq_nowait. Also, get rid of blk_tag_to_qc_t and open-code it instead. Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-12-17blk-mq: enable IO poll if .nr_queues of type poll > 0Ming Lei2-2/+4
The queue mapping of type poll only exists when set->map[HCTX_TYPE_POLL].nr_queues is bigger than zero, so enhance the constraint by checking .nr_queues of type poll before enabling IO poll. Otherwise IO race & timeout can be observed when running block/007. Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-17blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight()Jens Axboe1-8/+8
There's a single user of this function, dm, and dm just wants to check if IO is inflight, not that it's just allocated. This fixes a hang with srp/002 in blktests with dm, where it tries to suspend but waits for inflight IO to finish first. As it checks for just allocated requests, this fails. Tested-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-17blk-mq: skip zero-queue maps in blk_mq_map_swqueueMing Lei1-0/+3
From 7e849dd9cf37 ("nvme-pci: don't share queue maps"), the mapping table won't be initialized actually if map->nr_queues is zero, so we can't use blk_mq_map_queue_type() to retrieve hctx any more. This way still may cause broken mapping, fix it by skipping zero-queues maps in blk_mq_map_swqueue(). Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Mike Snitzer <snitzer@redhat.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>
2018-12-17block: fix blk-iolatency accounting underflowDennis Zhou2-1/+6
The blk-iolatency controller measures the time from rq_qos_throttle() to rq_qos_done_bio() and attributes this time to the first bio that needs to create the request. This means if a bio is plug-mergeable or bio-mergeable, it gets to bypass the blk-iolatency controller. The recent series [1], to tag all bios w/ blkgs undermined how iolatency was determining which bios it was charging and should process in rq_qos_done_bio(). Because all bios are being tagged, this caused the atomic_t for the struct rq_wait inflight count to underflow and result in a stall. This patch adds a new flag BIO_TRACKED to let controllers know that a bio is going through the rq_qos path. blk-iolatency now checks if this flag is set to see if it should process the bio in rq_qos_done_bio(). Overloading BLK_QUEUE_ENTERED works, but makes the flag rules confusing. BIO_THROTTLED was another candidate, but the flag is set for all bios that have gone through blk-throttle code. Overloading a flag comes with the burden of making sure that when either implementation changes, a change in setting rules for one doesn't cause a bug in the other. So here, we unfortunately opt for adding a new flag. [1] https://lore.kernel.org/lkml/20181205171039.73066-1-dennis@kernel.org/ Fixes: 5cdf2e3fea5e ("blkcg: associate blkg when associating a device") Signed-off-by: Dennis Zhou <dennis@kernel.org> Cc: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-17blk-mq: fix dispatch from sw queueMing Lei4-45/+68
When a request is added to rq list of sw queue(ctx), the rq may be from a different type of hctx, especially after multi queue mapping is introduced. So when dispach request from sw queue via blk_mq_flush_busy_ctxs() or blk_mq_dequeue_from_ctx(), one request belonging to other queue type of hctx can be dispatched to current hctx in case that read queue or poll queue is enabled. This patch fixes this issue by introducing per-queue-type list. Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Changed by me to not use separately cacheline aligned lists, just place them all in the same cacheline where we had just the one list and lock before. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-17block: mq-deadline: Fix write completion handlingDamien Le Moal3-2/+14
For a zoned block device using mq-deadline, if a write request for a zone is received while another write was already dispatched for the same zone, dd_dispatch_request() will return NULL and the newly inserted write request is kept in the scheduler queue waiting for the ongoing zone write to complete. With this behavior, when no other request has been dispatched, rq_list in blk_mq_sched_dispatch_requests() is empty and blk_mq_sched_mark_restart_hctx() not called. This in turn leads to __blk_mq_free_request() call of blk_mq_sched_restart() to not run the queue when the already dispatched write request completes. The newly dispatched request stays stuck in the scheduler queue until eventually another request is submitted. This problem does not affect SCSI disk as the SCSI stack handles queue restart on request completion. However, this problem is can be triggered the nullblk driver with zoned mode enabled. Fix this by always requesting a queue restart in dd_dispatch_request() if no request was dispatched while WRITE requests are queued. Fixes: 5700f69178e9 ("mq-deadline: Introduce zone locking support") Cc: <stable@vger.kernel.org> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Add missing export of blk_mq_sched_restart() Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-17blk-mq: only dispatch to non-defauly queue maps if they have queuesChristoph Hellwig1-5/+8
We should check if a given queue map actually has queues enabled before dispatching to it. This allows drivers to not initialize optional but not used map types, which subsequently will allow fixing problems with queue map rebuilds for that case. Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-17blk-mq: export hctx->type in debugfs instead of sysfsMing Lei2-17/+16
Now we only export hctx->type via sysfs, and there isn't such info in hctx entry under debugfs. We often use debugfs only to diagnose queue mapping issue, so add the support in debugfs. Queue mapping becomes a bit more complicated after multiple queue mapping is supported, we may write blktest to verify if queue mapping is valid based on blk-mq-debugfs. Given not necessary to export hctx->type twice, so remove the export from sysfs. Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Mike Snitzer <snitzer@redhat.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>
2018-12-17blk-mq: fix allocation for queue mapping tableMing Lei1-1/+1
Type of each element in queue mapping table is 'unsigned int, intead of 'struct blk_mq_queue_map)', so fix it. Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-16blk-wbt: export internal state via debugfsMing Lei1-0/+91
This information is helpful to either investigate issues, or understand wbt's internal behaviour. Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-16blk-mq-debugfs: support rq_qosMing Lei4-0/+97
blk-mq-debugfs has been proved as very helpful for debug some tough issues, such as IO hang. We have seen blk-wbt related IO hang several times, even inside Red Hat BZ, there is such report not sovled yet, so this patch adds support debugfs on rq_qos. Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-16block: clear REQ_HIPRI if polling is not supportedChristoph Hellwig1-0/+3
This prevents a HIPRI bio from being submitted through a stacking driver that does not support polling and thus won't poll for I/O completion. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-16blk-mq: replace and kill blk_mq_request_issue_directlyJianchao Wang3-11/+8
Replace blk_mq_request_issue_directly with blk_mq_try_issue_directly in blk_insert_cloned_request and kill it as nobody uses it any more. Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-16blk-mq: issue directly with bypass 'false' in blk_mq_sched_insert_requestsJianchao Wang2-16/+12
It is not necessary to issue request directly with bypass 'true' in blk_mq_sched_insert_requests and handle the non-issued requests itself. Just set bypass to 'false' and let blk_mq_try_issue_directly handle them totally. Remove the blk_rq_can_direct_dispatch check, because blk_mq_try_issue_directly can handle it well.If request is direct-issued unsuccessfully, insert the reset. Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-16blk-mq: refactor the code of issue request directlyJianchao Wang1-49/+54
Merge blk_mq_try_issue_directly and __blk_mq_try_issue_directly into one interface to unify the interfaces to issue requests directly. The merged interface takes over the requests totally, it could insert, end or do nothing based on the return value of .queue_rq and 'bypass' parameter. Then caller needn't any other handling any more and then code could be cleaned up. And also the commit c616cbee ( blk-mq: punt failed direct issue to dispatch list ) always inserts requests to hctx dispatch list whenever get a BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE, this is overkill and will harm the merging. We just need to do that for the requests that has been through .queue_rq. This patch also could fix this. Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-16block: remove the bio_integrity_advance exportChristoph Hellwig1-1/+0
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-16block: remove the bioset_integrity_free exportChristoph Hellwig1-1/+0
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-14block: remove the unused bio_set_pages_dirty and bio_check_pages_dirty exportsChristoph Hellwig1-2/+0
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-14block: remove the unused bio_iov_iter_get_pages exportChristoph Hellwig1-1/+0
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-14block: remove the blk_recount_segments exportChristoph Hellwig1-1/+0
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-14block: remove the bio_phys_segments exportChristoph Hellwig1-2/+1
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-13blk-mq-rdma: pass in queue map to blk_mq_rdma_map_queuesSagi Grimberg1-4/+4
Will be used by nvme-rdma for queue map separation support. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-12-12blkcg: handle dying request_queue when associating a blkgDennis Zhou1-0/+6
Between v3 [1] and v4 [2] of the blkg association series, the association point moved from generic_make_request_checks(), which is called after the request enters the queue, to bio_set_dev(), which is when the bio is formed before submit_bio(). When the request_queue goes away, the blkgs supporting the request_queue are destroyed and then the q->root_blkg is set to %NULL. This patch adds a %NULL check to blkg_tryget_closest() to prevent the NPE caused by the above. It also adds a guard to see if the request_queue is dying when creating a blkg to prevent creating a blkg for a dead request_queue. [1] https://lore.kernel.org/lkml/20180911184137.35897-1-dennisszhou@gmail.com/ [2] https://lore.kernel.org/lkml/20181126211946.77067-1-dennis@kernel.org/ Fixes: 5cdf2e3fea5e ("blkcg: associate blkg when associating a device") Reported-and-tested-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Dennis Zhou <dennis@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-12block: deactivate blk_stat timer in wbt_disable_default()Ming Lei2-1/+8
rwb_enabled() can't be changed when there is any inflight IO. wbt_disable_default() may set rwb->wb_normal as zero, however the blk_stat timer may still be pending, and the timer function will update wrb->wb_normal again. This patch introduces blk_stat_deactivate() and applies it in wbt_disable_default(), then the following IO hang triggered when running parted & switching io scheduler can be fixed: [ 369.937806] INFO: task parted:3645 blocked for more than 120 seconds. [ 369.938941] Not tainted 4.20.0-rc6-00284-g906c801e5248 #498 [ 369.939797] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 369.940768] parted D 0 3645 3239 0x00000000 [ 369.941500] Call Trace: [ 369.941874] ? __schedule+0x6d9/0x74c [ 369.942392] ? wbt_done+0x5e/0x5e [ 369.942864] ? wbt_cleanup_cb+0x16/0x16 [ 369.943404] ? wbt_done+0x5e/0x5e [ 369.943874] schedule+0x67/0x78 [ 369.944298] io_schedule+0x12/0x33 [ 369.944771] rq_qos_wait+0xb5/0x119 [ 369.945193] ? karma_partition+0x1c2/0x1c2 [ 369.945691] ? wbt_cleanup_cb+0x16/0x16 [ 369.946151] wbt_wait+0x85/0xb6 [ 369.946540] __rq_qos_throttle+0x23/0x2f [ 369.947014] blk_mq_make_request+0xe6/0x40a [ 369.947518] generic_make_request+0x192/0x2fe [ 369.948042] ? submit_bio+0x103/0x11f [ 369.948486] ? __radix_tree_lookup+0x35/0xb5 [ 369.949011] submit_bio+0x103/0x11f [ 369.949436] ? blkg_lookup_slowpath+0x25/0x44 [ 369.949962] submit_bio_wait+0x53/0x7f [ 369.950469] blkdev_issue_flush+0x8a/0xae [ 369.951032] blkdev_fsync+0x2f/0x3a [ 369.951502] do_fsync+0x2e/0x47 [ 369.951887] __x64_sys_fsync+0x10/0x13 [ 369.952374] do_syscall_64+0x89/0x149 [ 369.952819] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 369.953492] RIP: 0033:0x7f95a1e729d4 [ 369.953996] Code: Bad RIP value. [ 369.954456] RSP: 002b:00007ffdb570dd48 EFLAGS: 00000246 ORIG_RAX: 000000000000004a [ 369.955506] RAX: ffffffffffffffda RBX: 000055c2139c6be0 RCX: 00007f95a1e729d4 [ 369.956389] RDX: 0000000000000001 RSI: 0000000000001261 RDI: 0000000000000004 [ 369.957325] RBP: 0000000000000002 R08: 0000000000000000 R09: 000055c2139c6ce0 [ 369.958199] R10: 0000000000000000 R11: 0000000000000246 R12: 000055c2139c0380 [ 369.959143] R13: 0000000000000004 R14: 0000000000000100 R15: 0000000000000008 Cc: stable@vger.kernel.org Cc: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-11block: Fix null_blk_zoned creation failure with small number of zonesShin'ichiro Kawasaki1-1/+1
null_blk_zoned creation fails if the number of zones specified is equal to or is smaller than 64 due to a memory allocation failure in blk_alloc_zones(). With such a small number of zones, the required memory size for all zones descriptors fits in a single page, and the page order for alloc_pages_node() is zero. Allow this value in blk_alloc_zones() for the allocation to succeed. Fixes: bf5054569653 "block: Introduce blk_revalidate_disk_zones()" Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10block/bio: Do not zero user pagesKeith Busch1-1/+2
We don't need to zero fill the bio if not using kernel allocated pages. Fixes: f3587d76da05 ("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>
2018-12-10block: return just one value from part_in_flightMikulas Patocka4-34/+21
The previous patches deleted all the code that needed the second value returned from part_in_flight - now the kernel only uses the first value. Consequently, part_in_flight (and blk_mq_in_flight) may be changed so that it only returns one value. This patch just refactors the code, there's no functional change. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10block: switch to per-cpu in-flight countersMikulas Patocka1-10/+33
Now when part_round_stats is gone, we can switch to per-cpu in-flight counters. We use the local-atomic type local_t, so that if part_inc_in_flight or part_dec_in_flight is reentrantly called from an interrupt, the value will be correct. The other counters could be corrupted due to reentrant interrupt, but the corruption only results in slight counter skew - the in_flight counter must be exact, so it needs local_t. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10block: delete part_round_stats and switch to less precise countingMikulas Patocka5-68/+25
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>
2018-12-10block: stop passing 'cpu' to all percpu stats methodsMike Snitzer5-35/+30
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>
2018-12-09Merge tag 'v4.20-rc6' into for-4.21/blockJens Axboe4-28/+111
Pull in v4.20-rc6 to resolve the conflict in NVMe, but also to get the two corruption fixes. We're going to be overhauling the direct dispatch path, and we need to do that on top of the changes we made for that in mainline. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07blk-mq: re-build queue map in case of kdump kernelMing Lei1-2/+3
Now almost all .map_queues() implementation based on managed irq affinity doesn't update queue mapping and it just retrieves the old built mapping, so if nr_hw_queues is changed, the mapping talbe includes stale mapping. And only blk_mq_map_queues() may rebuild the mapping talbe. One case is that we limit .nr_hw_queues as 1 in case of kdump kernel. However, drivers often builds queue mapping before allocating tagset via pci_alloc_irq_vectors_affinity(), but set->nr_hw_queues can be set as 1 in case of kdump kernel, so wrong queue mapping is used, and kernel panic[1] is observed during booting. This patch fixes the kernel panic triggerd on nvme by rebulding the mapping table via blk_mq_map_queues(). [1] kernel panic log [ 4.438371] nvme nvme0: 16/0/0 default/read/poll queues [ 4.443277] BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 [ 4.444681] PGD 0 P4D 0 [ 4.445367] Oops: 0000 [#1] SMP NOPTI [ 4.446342] CPU: 3 PID: 201 Comm: kworker/u33:10 Not tainted 4.20.0-rc5-00664-g5eb02f7ee1eb-dirty #459 [ 4.447630] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-2.fc27 04/01/2014 [ 4.448689] Workqueue: nvme-wq nvme_scan_work [nvme_core] [ 4.449368] RIP: 0010:blk_mq_map_swqueue+0xfb/0x222 [ 4.450596] Code: 04 f5 20 28 ef 81 48 89 c6 39 55 30 76 93 89 d0 48 c1 e0 04 48 03 83 f8 05 00 00 48 8b 00 42 8b 3c 28 48 8b 43 58 48 8b 04 f8 <48> 8b b8 98 00 00 00 4c 0f a3 37 72 42 f0 4c 0f ab 37 66 8b b8 f6 [ 4.453132] RSP: 0018:ffffc900023b3cd8 EFLAGS: 00010286 [ 4.454061] RAX: 0000000000000000 RBX: ffff888174448000 RCX: 0000000000000001 [ 4.456480] RDX: 0000000000000001 RSI: ffffe8feffc506c0 RDI: 0000000000000001 [ 4.458750] RBP: ffff88810722d008 R08: ffff88817647a880 R09: 0000000000000002 [ 4.464580] R10: ffffc900023b3c10 R11: 0000000000000004 R12: ffff888174448538 [ 4.467803] R13: 0000000000000004 R14: 0000000000000001 R15: 0000000000000001 [ 4.469220] FS: 0000000000000000(0000) GS:ffff88817bac0000(0000) knlGS:0000000000000000 [ 4.471554] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 4.472464] CR2: 0000000000000098 CR3: 0000000174e4e001 CR4: 0000000000760ee0 [ 4.474264] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 4.476007] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 4.477061] PKRU: 55555554 [ 4.477464] Call Trace: [ 4.478731] blk_mq_init_allocated_queue+0x36a/0x3ad [ 4.479595] blk_mq_init_queue+0x32/0x4e [ 4.480178] nvme_validate_ns+0x98/0x623 [nvme_core] [ 4.480963] ? nvme_submit_sync_cmd+0x1b/0x20 [nvme_core] [ 4.481685] ? nvme_identify_ctrl.isra.8+0x70/0xa0 [nvme_core] [ 4.482601] nvme_scan_work+0x23a/0x29b [nvme_core] [ 4.483269] ? _raw_spin_unlock_irqrestore+0x25/0x38 [ 4.483930] ? try_to_wake_up+0x38d/0x3b3 [ 4.484478] ? process_one_work+0x179/0x2fc [ 4.485118] process_one_work+0x1d3/0x2fc [ 4.485655] ? rescuer_thread+0x2ae/0x2ae [ 4.486196] worker_thread+0x1e9/0x2be [ 4.486841] kthread+0x115/0x11d [ 4.487294] ? kthread_park+0x76/0x76 [ 4.487784] ret_from_fork+0x3a/0x50 [ 4.488322] Modules linked in: nvme nvme_core qemu_fw_cfg virtio_scsi ip_tables [ 4.489428] Dumping ftrace buffer: [ 4.489939] (ftrace buffer empty) [ 4.490492] CR2: 0000000000000098 [ 4.491052] ---[ end trace 03cd268ad5a86ff7 ]--- Cc: Christoph Hellwig <hch@lst.de> Cc: linux-nvme@lists.infradead.org Cc: David Milburn <dmilburn@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07block: convert io-latency to use rq_qos_waitJosef Bacik1-23/+8
Now that we have this common helper, convert io-latency over to use it as well. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07block: convert wbt_wait() to use rq_qos_wait()Josef Bacik1-54/+11
Now that we have rq_qos_wait() in place, convert wbt_wait() over to using it with it's specific callbacks. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07block: add rq_qos_wait to rq_qosJosef Bacik2-0/+92
Originally when I split out the common code from blk-wbt into rq_qos I left the wbt_wait() where it was and simply copied and modified it slightly to work for io-latency. However they are both basically the same thing, and as time has gone on wbt_wait() has ended up much smarter and kinder than it was when I copied it into io-latency, which means io-latency has lost out on these improvements. Since they are the same thing essentially except for a few minor things, create rq_qos_wait() that replicates what wbt_wait() currently does with callbacks that can be passed in for the snowflakes to do their own thing as appropriate. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07blkcg: rename blkg_try_get() to blkg_tryget()Dennis Zhou3-4/+3
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>