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* blk-mq: fail the request in case issue failureMing Lei2018-07-221-2/+6
| | | | | | | | | | | | | | | | | | | | | Inside blk_mq_try_issue_list_directly(), if the request is issued as failed, we shouldn't try to do it again, otherwise the warning in blk_mq_start_request() will be triggered. This change is aligned to behaviour of other ways of request issue & dispatch. Fixes: 6ce3dd6eec1 ("blk-mq: issue directly if hw queue isn't busy in case of 'none'") Cc: Kashyap Desai <kashyap.desai@broadcom.com> Cc: Laurence Oberman <loberman@redhat.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Kashyap Desai <kashyap.desai@broadcom.com> Cc: kernel test robot <rong.a.chen@intel.com> Cc: LKP <lkp@01.org> Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-rq-qos: make depth comparisons unsignedJosef Bacik2018-07-222-5/+5
| | | | | | | | | With the change to use UINT_MAX I broke the depth check as any value of inflight (ie 0) would be less than (int)UINT_MAX. Fix this by changing everything to unsigned int to match the depth. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blkcg: Track DISCARD statistics and output them in cgroup io.statTejun Heo2018-07-181-4/+9
| | | | | | | | | | | Add tracking of REQ_OP_DISCARD ios to the per-cgroup io.stat. Two fields, dbytes and dios, to respectively count the total bytes and number of discards are added. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Andy Newell <newella@fb.com> Cc: Michael Callahan <michaelcallahan@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: Track DISCARD statistics and output them in stat and diskstatMichael Callahan2018-07-182-5/+17
| | | | | | | | | | | | | | | | | | | | | | Add tracking of REQ_OP_DISCARD ios to the partition statistics and append them to the various stat files in /sys as well as /proc/diskstats. These are tracked with the same four stats as reads and writes: Number of discard ios completed. Number of discard ios merged Number of discard sectors completed Milliseconds spent on discard requests This is done via adding a new STAT_DISCARD define to genhd.h and then using it to index that stat field for discard requests. tj: Refreshed on top of v4.17 and other previous updates. Signed-off-by: Michael Callahan <michaelcallahan@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Andy Newell <newella@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: Add and use op_stat_group() for indexing disk_stat fields.Michael Callahan2018-07-182-13/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add and use a new op_stat_group() function for indexing partition stat fields rather than indexing them by rq_data_dir() or bio_data_dir(). This function works similarly to op_is_sync() in that it takes the request::cmd_flags or bio::bi_opf flags and determines which stats should et updated. In addition, the second parameter to generic_start_io_acct() and generic_end_io_acct() is now a REQ_OP rather than simply a read or write bit and it uses op_stat_group() on the parameter to determine the stat group. Note that the partition in_flight counts are not part of the per-cpu statistics and as such are not indexed via this function. It's now indexed by op_is_write(). tj: Refreshed on top of v4.17. Updated to pass around REQ_OP. Signed-off-by: Michael Callahan <michaelcallahan@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Matias Bjorling <mb@lightnvm.io> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: Define and use STAT_READ and STAT_WRITEMichael Callahan2018-07-182-16/+16
| | | | | | | | | | | | | | | Add defines for STAT_READ and STAT_WRITE for indexing the partition stat entries. This clarifies some fs/ code which has hardcoded 1 for STAT_WRITE and will make it easier to extend the stats with additional fields. tj: Refreshed on top of v4.17. Signed-off-by: Michael Callahan <michaelcallahan@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: issue directly if hw queue isn't busy in case of 'none'Ming Lei2018-07-173-2/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | In case of 'none' io scheduler, when hw queue isn't busy, it isn't necessary to enqueue request to sw queue and dequeue it from sw queue because request may be submitted to hw queue asap without extra cost, meantime there shouldn't be much request in sw queue, and we don't need to worry about effect on IO merge. There are still some single hw queue SCSI HBAs(HPSA, megaraid_sas, ...) which may connect high performance devices, so 'none' is often required for obtaining good performance. This patch improves IOPS and decreases CPU unilization on megaraid_sas, per Kashyap's test. Cc: Kashyap Desai <kashyap.desai@broadcom.com> Cc: Laurence Oberman <loberman@redhat.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: Hannes Reinecke <hare@suse.de> Reported-by: Kashyap Desai <kashyap.desai@broadcom.com> Tested-by: Kashyap Desai <kashyap.desai@broadcom.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-iolatency: truncate our current timeJosef Bacik2018-07-161-0/+6
| | | | | | | | | | | | | In our longer tests we noticed that some boxes would degrade to the point of uselessness. This is because we truncate the current time when saving it in our bio, but I was using the raw current time to subtract from. So once the box had been up a certain amount of time it would appear as if our IO's were taking several years to complete. Fix this by truncating the current time so it matches the issue time. Verified this worked by running with this patch for a week on our test tier. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-iolatency: don't change the latency windowJosef Bacik2018-07-161-10/+0
| | | | | | | | | | Early versions of these patches had us waiting for seconds at a time during submission, so we had to adjust the timing window we monitored for latency. Now we don't do things like that so this is unnecessary code. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bsg: remove read/write supportChristoph Hellwig2018-07-121-454/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The code poses a security risk due to user memory access in ->release and had an API that can't be used reliably. As far as we know it was never used for real, but if that turns out wrong we'll have to revert this commit and come up with a band aid. Jann Horn did look software archives for users of this interface, and the only users found were example code in sg3_utils, and optional support in an optional module of the tgt user space iscsi target, which looks like a proof of concept extension of the /dev/sg read/write support. Tony Battersby chimes in that the code is basically unsafe to use in general: The read/write interface on /dev/bsg is impossible to use safely because the list of completed commands is per-device (bd->done_list) rather than per-fd like it is with /dev/sg. So if program A and program B are both using the write/read interface on the same bsg device, then their command responses will get mixed up, and program A will read() some command results from program B and vice versa. So no, I don't use read/write on /dev/bsg. From a security standpoint, it should definitely be fixed or removed. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-iolatency: fix max_depth comparisonsJosef Bacik2018-07-111-6/+6
| | | | | | | | | | max_depth used to be a u64, but I changed it to a unsigned int but didn't convert my comparisons over everywhere. Fix by using UINT_MAX everywhere instead of (u64)-1. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: iolatency: avoid 64-bit divisionArnd Bergmann2018-07-101-2/+1
| | | | | | | | | | | | | | | | On 32-bit architectures, dividing a 64-bit number needs to use the do_div() function or something like it to avoid a link failure: block/blk-iolatency.o: In function `iolatency_prfill_limit': blk-iolatency.c:(.text+0x8cc): undefined reference to `__aeabi_uldivmod' Using div_u64() gives us the best output and avoids the need for an explicit cast. Fixes: d70675121546 ("block: introduce blk-iolatency io controller") Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: Add default switch case to blk_pm_allow_request() to kill warningGeert Uytterhoeven2018-07-091-2/+2
| | | | | | | | | | | | | | | | | With gcc 4.9.0 and 7.3.0: block/blk-core.c: In function 'blk_pm_allow_request': block/blk-core.c:2747:2: warning: enumeration value 'RPM_ACTIVE' not handled in switch [-Wswitch] switch (rq->q->rpm_status) { ^ Convert the return statement below the switch() block into a default case to fix this. Fixes: e4f36b249b4d4e75 ("block: fix peeking requests during PM") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: fix infinite loop if the device loses discard capabilityMikulas Patocka2018-07-091-0/+10
| | | | | | | | | | | | | | | If __blkdev_issue_discard is in progress and a device mapper device is reloaded with a table that doesn't support discard, q->limits.max_discard_sectors is set to zero. This results in infinite loop in __blkdev_issue_discard. This patch checks if max_discard_sectors is zero and aborts with -EOPNOTSUPP. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Tested-by: Zdenek Kabelac <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block, mm: remove unnecessary __GFP_HIGH flagShakeel Butt2018-07-091-1/+1
| | | | | | | | The flag GFP_ATOMIC already contains __GFP_HIGH. There is no need to explicitly or __GFP_HIGH again. So, just remove unnecessary __GFP_HIGH. Signed-off-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: introduce blk-iolatency io controllerJosef Bacik2018-07-095-0/+957
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current IO controllers for the block layer are less than ideal for our use case. The io.max controller is great at hard limiting, but it is not work conserving. This patch introduces io.latency. You provide a latency target for your group and we monitor the io in short windows to make sure we are not exceeding those latency targets. This makes use of the rq-qos infrastructure and works much like the wbt stuff. There are a few differences from wbt - It's bio based, so the latency covers the whole block layer in addition to the actual io. - We will throttle all IO types that comes in here if we need to. - We use the mean latency over the 100ms window. This is because writes can be particularly fast, which could give us a false sense of the impact of other workloads on our protected workload. - By default there's no throttling, we set the queue_depth to INT_MAX so that we can have as many outstanding bio's as we're allowed to. Only at throttle time do we pay attention to the actual queue depth. - We backcharge cgroups for root cg issued IO and induce artificial delays in order to deal with cases like metadata only or swap heavy workloads. In testing this has worked out relatively well. Protected workloads will throttle noisy workloads down to 1 io at time if they are doing normal IO on their own, or induce up to a 1 second delay per syscall if they are doing a lot of root issued IO (metadata/swap IO). Our testing has revolved mostly around our production web servers where we have hhvm (the web server application) in a protected group and everything else in another group. We see slightly higher requests per second (RPS) on the test tier vs the control tier, and much more stable RPS across all machines in the test tier vs the control tier. Another test we run is a slow memory allocator in the unprotected group. Before this would eventually push us into swap and cause the whole box to die and not recover at all. With these patches we see slight RPS drops (usually 10-15%) before the memory consumer is properly killed and things recover within seconds. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* rq-qos: introduce dio_bio callbackJosef Bacik2018-07-093-0/+16
| | | | | | | | | | wbt cares only about request completion time, but controllers may need information that is on the bio itself, so add a done_bio callback for rq-qos so things like blk-iolatency can use it to have the bio when it completes. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: remove external dependency on wbt_flagsJosef Bacik2018-07-096-42/+68
| | | | | | | | | We don't really need to save this stuff in the core block code, we can just pass the bio back into the helpers later on to derive the same flags and update the rq->wbt_flags appropriately. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-rq-qos: refactor out common elements of blk-wbtJosef Bacik2018-07-099-249/+476
| | | | | | | | | | blkcg-qos is going to do essentially what wbt does, only on a cgroup basis. Break out the common code that will be shared between blkcg-qos and wbt into blk-rq-qos.* so they can both utilize the same infrastructure. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-stat: export helpers for modifying blk_rq_statJosef Bacik2018-07-092-8/+12
| | | | | | | | | We need to use blk_rq_stat in the blkcg qos stuff, so export some of these helpers so they can be used by other things. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blkcg: add generic throttling mechanismJosef Bacik2018-07-091-0/+220
| | | | | | | | | | | | | | | | | | | | | | | Since IO can be issued from literally anywhere it's almost impossible to do throttling without having some sort of adverse effect somewhere else in the system because of locking or other dependencies. The best way to solve this is to do the throttling when we know we aren't holding any other kernel resources. Do this by tracking throttling in a per-blkg basis, and if we require throttling flag the task that it needs to check before it returns to user space and possibly sleep there. This is to address the case where a process is doing work that is generating IO that can't be throttled, whether that is directly with a lot of REQ_META IO, or indirectly by allocating so much memory that it is swamping the disk with REQ_SWAP. We can't use task_add_work as we don't want to induce a memory allocation in the IO path, so simply saving the request queue in the task and flagging it to do the notify_resume thing achieves the same result without the overhead of a memory allocation. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* swap,blkcg: issue swap io with the appropriate contextTejun Heo2018-07-091-0/+24
| | | | | | | | | | | | | For backcharging we need to know who the page belongs to when swapping it out. We don't worry about things that do ->rw_page (zram etc) at the moment, we're only worried about pages that actually go to a block device. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-cgroup: allow controllers to output their own statsJosef Bacik2018-07-091-3/+44
| | | | | | | | | | | | | | blk-iolatency has a few stats that it would like to print out, and instead of adding a bunch of crap to the generic code just provide a helper so that controllers can add stuff to the stat line if they want to. Hide it behind a boot option since it changes the output of io.stat from normal, and these stats are only interesting to developers. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: add bi_blkg to the bio for cgroupsJosef Bacik2018-07-092-14/+30
| | | | | | | | | | | | | | | | | | | | | | | | Currently io.low uses a bi_cg_private to stash its private data for the blkg, however other blkcg policies may want to use this as well. Since we can get the private data out of the blkg, move this to bi_blkg in the bio and make it generic, then we can use bio_associate_blkg() to attach the blkg to the bio. Theoretically we could simply replace the bi_css with this since we can get to all the same information from the blkg, however you have to lookup the blkg, so for example wbc_init_bio() would have to lookup and possibly allocate the blkg for the css it was trying to attach to the bio. This could be problematic and result in us either not attaching the css at all to the bio, or falling back to the root blkcg if we are unable to allocate the corresponding blkg. So for now do this, and in the future if possible we could just replace the bi_css with bi_blkg and update the helpers to do the correct translation. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: dequeue request one by one from sw queue if hctx is busyMing Lei2018-07-093-10/+43
| | | | | | | | | | | | | | | | | | | | | It won't be efficient to dequeue request one by one from sw queue, but we have to do that when queue is busy for better merge performance. This patch takes the Exponential Weighted Moving Average(EWMA) to figure out if queue is busy, then only dequeue request one by one from sw queue when queue is busy. Fixes: b347689ffbca ("blk-mq-sched: improve dispatching from sw queue") Cc: Kashyap Desai <kashyap.desai@broadcom.com> Cc: Laurence Oberman <loberman@redhat.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: Hannes Reinecke <hare@suse.de> Reported-by: Kashyap Desai <kashyap.desai@broadcom.com> Tested-by: Kashyap Desai <kashyap.desai@broadcom.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: only attempt to merge bio if there is rq in sw queueMing Lei2018-07-091-1/+2
| | | | | | | | | | | | | | | | | | | | | Only attempt to merge bio iff the ctx->rq_list isn't empty, because: 1) for high-performance SSD, most of times dispatch may succeed, then there may be nothing left in ctx->rq_list, so don't try to merge over sw queue if it is empty, then we can save one acquiring of ctx->lock 2) we can't expect good merge performance on per-cpu sw queue, and missing one merge on sw queue won't be a big deal since tasks can be scheduled from one CPU to another. Cc: Laurence Oberman <loberman@redhat.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Bart Van Assche <bart.vanassche@wdc.com> Tested-by: Kashyap Desai <kashyap.desai@broadcom.com> Reported-by: Kashyap Desai <kashyap.desai@broadcom.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>
* blk-mq: use list_splice_tail_init() to insert requestsMing Lei2018-07-091-7/+7
| | | | | | | | | | | | | | list_splice_tail_init() is much more faster than inserting each request one by one, given all requets in 'list' belong to same sw queue and ctx->lock is required to insert requests. Cc: Laurence Oberman <loberman@redhat.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Bart Van Assche <bart.vanassche@wdc.com> Tested-by: Kashyap Desai <kashyap.desai@broadcom.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>
* blk-mq: fix typo in a function commentMinwoo Im2018-07-091-1/+1
| | | | | | | | Fix typo in a function blk_mq_alloc_tag_set() comment. if if it too large -> if it's too large. Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: code clean-up by adding an API to clear set->mq_mapMinwoo Im2018-07-093-5/+12
| | | | | | | | | | | set->mq_map is now currently cleared if something goes wrong when establishing a queue map in blk-mq-pci.c. It's also cleared before updating a queue map in blk_mq_update_queue_map(). This patch provides an API to clear set->mq_map to make it clear. Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* partitions/ldm: remove redundant pointer dgrpColin Ian King2018-07-091-3/+0
| | | | | | | | | | | Pointer dgrp is being assigned but is never used hence it is redundant and can be removed. Cleans up clang warning: warning: variable 'dgrp' set but not used [-Wunused-but-set-variable] Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Block: blk-throttle: set low_valid immediately once one cgroup has io.low ↵Liu Bo2018-07-091-1/+3
| | | | | | | | | | configured Once one cgroup has io.low configured, @low_valid becomes true and other cgroups won't switch it back whatsoever. Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: Document how blk_update_request() handles RQF_SPECIAL_PAYLOAD requestsBart Van Assche2018-07-091-0/+4
| | | | | | | | | | | | | | | | | | | The payload of struct request is stored in the request.bio chain if the RQF_SPECIAL_PAYLOAD flag is not set and in request.special_vec if RQF_SPECIAL_PAYLOAD has been set. However, blk_update_request() iterates over req->bio whether or not RQF_SPECIAL_PAYLOAD has been set. Additionally, the RQF_SPECIAL_PAYLOAD flag is ignored by blk_rq_bytes() which means that the value returned by that function is incorrect if the RQF_SPECIAL_PAYLOAD flag has been set. It is not clear to me whether this is an oversight or whether this happened on purpose. Anyway, document that it is known that both functions ignore RQF_SPECIAL_PAYLOAD. See also commit f9d03f96b988 ("block: improve handling of the magic discard payload"). Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: avoid to synchronize rcu inside blk_cleanup_queue()Ming Lei2018-07-091-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | SCSI probing may synchronously create and destroy a lot of request_queues for non-existent devices. Any synchronize_rcu() in queue creation or destroy path may introduce long latency during booting, see detailed description in comment of blk_register_queue(). This patch removes one synchronize_rcu() inside blk_cleanup_queue() for this case, commit c2856ae2f315d75(blk-mq: quiesce queue before freeing queue) needs synchronize_rcu() for implementing blk_mq_quiesce_queue(), but when queue isn't initialized, it isn't necessary to do that since only pass-through requests are involved, no original issue in scsi_execute() at all. Without this patch and previous one, it may take more 20+ seconds for virtio-scsi to complete disk probe. With the two patches, the time becomes less than 100ms. Fixes: c2856ae2f315d75 ("blk-mq: quiesce queue before freeing queue") Reported-by: Andrew Jones <drjones@redhat.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: linux-scsi@vger.kernel.org Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Tested-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: remove synchronize_rcu() from blk_mq_del_queue_tag_set()Ming Lei2018-07-092-88/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have to remove synchronize_rcu() from blk_queue_cleanup(), otherwise long delay can be caused during lun probe. For removing it, we have to avoid to iterate the set->tag_list in IO path, eg, blk_mq_sched_restart(). This patch reverts 5b79413946d (Revert "blk-mq: don't handle TAG_SHARED in restart"). Given we have fixed enough IO hang issue, and there isn't any reason to restart all queues in one tags any more, see the following reasons: 1) blk-mq core can deal with shared-tags case well via blk_mq_get_driver_tag(), which can wake up queues waiting for driver tag. 2) SCSI is a bit special because it may return BLK_STS_RESOURCE if queue, target or host is ready, but SCSI built-in restart can cover all these well, see scsi_end_request(), queue will be rerun after any request initiated from this host/target is completed. In my test on scsi_debug(8 luns), this patch may improve IOPS by 20% ~ 30% when running I/O on these 8 luns concurrently. Fixes: 705cda97ee3a ("blk-mq: Make it safe to use RCU to iterate over blk_mq_tag_set.tag_list") Cc: Omar Sandoval <osandov@fb.com> Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: linux-scsi@vger.kernel.org Reported-by: Andrew Jones <drjones@redhat.com> Tested-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: introduce new lock for protecting hctx->dispatch_waitMing Lei2018-07-091-9/+17
| | | | | | | | | | | | | | | | | | | | Now hctx->lock is only acquired when adding hctx->dispatch_wait to one wait queue, but not held when removing it from the wait queue. IO hang can be observed easily if SCHED RESTART is disabled, that means now RESTART exits just for fixing the issue in blk_mq_mark_tag_wait(). This patch fixes the issue by introducing hctx->dispatch_wait_lock and holding it for removing hctx->dispatch_wait in blk_mq_dispatch_wake(), since we need to avoid acquiring hctx->lock in irq context. Fixes: eb619fdb2d4cb8b3d3419 ("blk-mq: fix issue with shared tag queue re-running") Cc: Christoph Hellwig <hch@lst.de> Cc: Omar Sandoval <osandov@fb.com> Cc: Bart Van Assche <bart.vanassche@wdc.com> Tested-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: don't pass **hctx to blk_mq_mark_tag_wait()Ming Lei2018-07-091-12/+11
| | | | | | | | | | | | 'hctx' won't be changed at all, so not necessary to pass '**hctx' to blk_mq_mark_tag_wait(). Cc: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bart.vanassche@wdc.com> Tested-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: cleanup blk_mq_get_driver_tag()Ming Lei2018-07-092-14/+8
| | | | | | | | | | | | | | | We never pass 'wait' as true to blk_mq_get_driver_tag(), and hence we never change '**hctx' as well. The last use of these went away with the flush cleanup, commit 0c2a6fe4dc3e. So cleanup the usage and remove the two extra parameters. Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: Christoph Hellwig <hch@lst.de> Tested-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block, bfq: give a better name to bfq_bfqq_may_idlePaolo Valente2018-07-091-8/+8
| | | | | | | | | | | | | The actual goal of the function bfq_bfqq_may_idle is to tell whether it is better to perform device idling (more precisely: I/O-dispatch plugging) for the input bfq_queue, either to boost throughput or to preserve service guarantees. This commit improves the name of the function accordingly. Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block, bfq: fix service being wrongly set to zero in case of preemptionPaolo Valente2018-07-092-12/+28
| | | | | | | | | | | | | | | | | | If - a bfq_queue Q preempts another queue, because one request of Q arrives in time, - but, after this preemption, Q is not the queue that is set in service, then Q->entity.service is set to 0 when Q is eventually set in service. But Q should have continued receiving service with its old budget (which is why preemption has occurred) and its old service. This commit addresses this issue by resetting service on queue real expiration. Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block, bfq: do not expire a queue that will deserve dispatch pluggingPaolo Valente2018-07-091-3/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | For some bfq_queues, BFQ plugs I/O dispatching when the queue becomes idle, and keeps the plug until a new request of the queue arrives, or a timeout fires. BFQ does so either to boost throughput or to preserve service guarantees for the queue. More precisely, for such a queue, plugging starts when the queue happens to have either no request enqueued, or no request in flight, that is, no request already dispatched but not yet completed. On the opposite end, BFQ may happen to expire a queue with no request enqueued, without doing any plugging, if the queue still has some request in flight. Unfortunately, such a premature expiration causes the queue to lose its chance to enjoy dispatch plugging a moment later, i.e., when its in-flight requests finally get completed. This breaks service guarantees for the queue. This commit prevents BFQ from expiring an empty queue if the latter still has in-flight requests. Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block, bfq: add/remove entity weights correctlyPaolo Valente2018-07-093-17/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To keep I/O throughput high as often as possible, BFQ performs I/O-dispatch plugging (aka device idling) only when beneficial exactly for throughput, or when needed for service guarantees (low latency, fairness). An important case where the latter condition holds is when the scenario is 'asymmetric' in terms of weights: i.e., when some bfq_queue or whole group of queues has a higher weight, and thus has to receive more service, than other queues or groups. Without dispatch plugging, lower-weight queues/groups may unjustly steal bandwidth to higher-weight queues/groups. To detect asymmetric scenarios, BFQ checks some sufficient conditions. One of these conditions is that active groups have different weights. BFQ controls this condition by maintaining a special set of unique weights of active groups (group_weights_tree). To this purpose, in the function bfq_active_insert/bfq_active_extract BFQ adds/removes the weight of a group to/from this set. Unfortunately, the function bfq_active_extract may happen to be invoked also for a group that is still active (to preserve the correct update of the next queue to serve, see comments in function bfq_no_longer_next_in_service() for details). In this case, removing the weight of the group makes the set group_weights_tree inconsistent. Service-guarantee violations follow. This commit addresses this issue by moving group_weights_tree insertions from their previous location (in bfq_active_insert) into the function __bfq_activate_entity, and by moving group_weights_tree extractions from bfq_active_extract to when the entity that represents a group remains throughly idle, i.e., with no request either enqueued or dispatched. Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: Make struct request_queue smaller for CONFIG_BLK_DEV_ZONED=nBart Van Assche2018-07-095-15/+38
| | | | | | | | | | | | | Exclude zoned block device members from struct request_queue for CONFIG_BLK_DEV_ZONED == n. Avoid breaking the build by only building the code that uses these struct request_queue members if CONFIG_BLK_DEV_ZONED != n. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Cc: Matias Bjorling <mb@lightnvm.io> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: Inline blk_queue_nr_zones()Bart Van Assche2018-07-091-1/+1
| | | | | | | | | | | Since the implementation of blk_queue_nr_zones() is trivial and since it only has a single caller, inline this function. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Cc: Matias Bjorling <mb@lightnvm.io> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: Remove a superfluous cast from blkdev_report_zones()Bart Van Assche2018-07-091-1/+1
| | | | | | | | | | | No cast is necessary when assigning a non-void pointer to a void pointer. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Cc: Matias Bjorling <mb@lightnvm.io> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Merge tag 'for-linus-20180629' of git://git.kernel.dk/linux-blockLinus Torvalds2018-06-302-0/+16
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block fixes from Jens Axboe: "Small set of fixes for this series. Mostly just minor fixes, the only oddball in here is the sg change. The sg change came out of the stall fix for NVMe, where we added a mempool and limited us to a single page allocation. CONFIG_SG_DEBUG sort-of ruins that, since we'd need to account for that. That's actually a generic problem, since lots of drivers need to allocate SG lists. So this just removes support for CONFIG_SG_DEBUG, which I added back in 2007 and to my knowledge it was never useful. Anyway, outside of that, this pull contains: - clone of request with special payload fix (Bart) - drbd discard handling fix (Bart) - SATA blk-mq stall fix (me) - chunk size fix (Keith) - double free nvme rdma fix (Sagi)" * tag 'for-linus-20180629' of git://git.kernel.dk/linux-block: sg: remove ->sg_magic member drbd: Fix drbd_request_prepare() discard handling blk-mq: don't queue more if we get a busy return block: Fix cloning of requests with a special payload nvme-rdma: fix possible double free of controller async event buffer block: Fix transfer when chunk sectors exceeds max
| * blk-mq: don't queue more if we get a busy returnJens Axboe2018-06-291-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some devices have different queue limits depending on the type of IO. A classic case is SATA NCQ, where some commands can queue, but others cannot. If we have NCQ commands inflight and encounter a non-queueable command, the driver returns busy. Currently we attempt to dispatch more from the scheduler, if we were able to queue some commands. But for the case where we ended up stopping due to BUSY, we should not attempt to retrieve more from the scheduler. If we do, we can get into a situation where we attempt to queue a non-queueable command, get BUSY, then successfully retrieve more commands from that scheduler and queue those. This can repeat forever, starving the non-queuable command indefinitely. Fix this by NOT attempting to pull more commands from the scheduler, if we get a BUSY return. This should also be more optimal in terms of letting requests stay in the scheduler for as long as possible, if we get a BUSY due to the regular out-of-tags condition. Reviewed-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: Fix cloning of requests with a special payloadBart Van Assche2018-06-281-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch avoids that removing a path controlled by the dm-mpath driver while mkfs is running triggers the following kernel bug: kernel BUG at block/blk-core.c:3347! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 20 PID: 24369 Comm: mkfs.ext4 Not tainted 4.18.0-rc1-dbg+ #2 RIP: 0010:blk_end_request_all+0x68/0x70 Call Trace: <IRQ> dm_softirq_done+0x326/0x3d0 [dm_mod] blk_done_softirq+0x19b/0x1e0 __do_softirq+0x128/0x60d irq_exit+0x100/0x110 smp_call_function_single_interrupt+0x90/0x330 call_function_single_interrupt+0xf/0x20 </IRQ> Fixes: f9d03f96b988 ("block: improve handling of the magic discard payload") Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | Merge tag 'for-linus-20180623' of git://git.kernel.dk/linux-blockLinus Torvalds2018-06-247-14/+6
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block fixes from Jens Axboe: - Further timeout fixes. We aren't quite there yet, so expect another round of fixes for that to completely close some of the IRQ vs completion races. (Christoph/Bart) - Set of NVMe fixes from the usual suspects, mostly error handling - Two off-by-one fixes (Dan) - Another bdi race fix (Jan) - Fix nbd reconfigure with NBD_DISCONNECT_ON_CLOSE (Doron) * tag 'for-linus-20180623' of git://git.kernel.dk/linux-block: blk-mq: Fix timeout handling in case the timeout handler returns BLK_EH_DONE bdi: Fix another oops in wb_workfn() lightnvm: Remove depends on HAS_DMA in case of platform dependency nvme-pci: limit max IO size and segments to avoid high order allocations nvme-pci: move nvme_kill_queues to nvme_remove_dead_ctrl nvme-fc: release io queues to allow fast fail nbd: Add the nbd NBD_DISCONNECT_ON_CLOSE config flag. block: sed-opal: Fix a couple off by one bugs blk-mq-debugfs: Off by one in blk_mq_rq_state_name() nvmet: reset keep alive timer in controller enable nvme-rdma: don't override opts->queue_size nvme-rdma: Fix command completion race at error recovery nvme-rdma: fix possible free of a non-allocated async event buffer nvme-rdma: fix possible double free condition when failing to create a controller Revert "block: Add warning for bi_next not NULL in bio_endio()" block: fix timeout changes for legacy request drivers
| * blk-mq: Fix timeout handling in case the timeout handler returns BLK_EH_DONEBart Van Assche2018-06-232-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Make sure that RQF_TIMED_OUT is cleared when a request is reused after a block driver timeout handler has returned BLK_EH_DONE. Fixes: da6612673988 ("blk-mq: don't time out requests again that are in the timeout handler") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jianchao Wang <jianchao.w.wang@oracle.com> Cc: Andrew Randrianasulu <randrianasulu@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: sed-opal: Fix a couple off by one bugsDan Carpenter2018-06-201-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | resp->num is the number of tokens in resp->tok[]. It gets set in response_parse(). So if n == resp->num then we're reading beyond the end of the data. Fixes: 455a7b238cd6 ("block: Add Sed-opal library") Reviewed-by: Scott Bauer <scott.bauer@intel.com> Tested-by: Scott Bauer <scott.bauer@intel.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-07 22:33:49 +0000