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* block: introduce blk_flush_queue to drive flush machineryMing Lei2014-09-251-1/+3
| | | | | | | | | | | | | | This patch introduces 'struct blk_flush_queue' and puts all flush machinery related fields into this structure, so that - flush implementation details aren't exposed to driver - it is easy to convert to per dispatch-queue flush machinery This patch is basically a mechanical replacement. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: move flush initialization to blk_flush_initMing Lei2014-09-251-3/+0
| | | | | | | | | These fields are always used with the flush request, so initialize them together. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: introduce blk_init_flush and its pairMing Lei2014-09-251-3/+2
| | | | | | | | | | | | These two temporary functions are introduced for holding flush initialization and de-initialization, so that we can introduce 'flush queue' easier in the following patch. And once 'flush queue' and its allocation/free functions are ready, they will be removed for sake of code readability. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge branch 'for-linus' into for-3.18/coreJens Axboe2014-09-111-1/+0
|\ | | | | | | | | | | | | | | | | | | | | A bit of churn on the for-linus side that would be nice to have in the core bits for 3.18, so pull it in to catch us up and make forward progress easier. Signed-off-by: Jens Axboe <axboe@fb.com> Conflicts: block/scsi_ioctl.c
| * scsi-mq: fix requests that use a separate CDB bufferTony Battersby2014-08-221-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes code such as the following with scsi-mq enabled: rq = blk_get_request(...); blk_rq_set_block_pc(rq); rq->cmd = my_cmd_buffer; /* separate CDB buffer */ blk_execute_rq_nowait(...); Code like this appears in e.g. sg_start_req() in drivers/scsi/sg.c (for large CDBs only). Without this patch, scsi_mq_prep_fn() will set rq->cmd back to rq->__cmd, causing the wrong CDB to be sent to the device. Signed-off-by: Tony Battersby <tonyb@cybernetics.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | block, bdi: an active gendisk always has a request_queue associated with itTejun Heo2014-09-081-7/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bdev_get_queue() returns the request_queue associated with the specified block_device. blk_get_backing_dev_info() makes use of bdev_get_queue() to determine the associated bdi given a block_device. All the callers of bdev_get_queue() including blk_get_backing_dev_info() assume that bdev_get_queue() may return NULL and implement NULL handling; however, bdev_get_queue() requires the passed in block_device is opened and attached to its gendisk. Because an active gendisk always has a valid request_queue associated with it, bdev_get_queue() can never return NULL and neither can blk_get_backing_dev_info(). Make it clear that neither of the two functions can return NULL and remove NULL handling from all the callers. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | block,scsi: fixup blk_get_request dead queue scenariosJoe Lawrence2014-08-281-17/+17
|/ | | | | | | | | | | | | | | | | | The blk_get_request function may fail in low-memory conditions or during device removal (even if __GFP_WAIT is set). To distinguish between these errors, modify the blk_get_request call stack to return the appropriate ERR_PTR. Verify that all callers check the return status and consider IS_ERR instead of a simple NULL pointer check. For consistency, make a similar change to the blk_mq_alloc_request leg of blk_get_request. It may fail if the queue is dead, or the caller was unwilling to wait. Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com> Acked-by: Jiri Kosina <jkosina@suse.cz> [for pktdvd] Acked-by: Boaz Harrosh <bharrosh@panasas.com> [for osd] Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: decouble blk-mq freezing from generic bypassingTejun Heo2014-07-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blk_mq freezing is entangled with generic bypassing which bypasses blkcg and io scheduler and lets IO requests fall through the block layer to the drivers in FIFO order. This allows forward progress on IOs with the advanced features disabled so that those features can be configured or altered without worrying about stalling IO which may lead to deadlock through memory allocation. However, generic bypassing doesn't quite fit blk-mq. blk-mq currently doesn't make use of blkcg or ioscheds and it maps bypssing to freezing, which blocks request processing and drains all the in-flight ones. This causes problems as bypassing assumes that request processing is online. blk-mq works around this by conditionally allowing request processing for the problem case - during queue initialization. Another weirdity is that except for during queue cleanup, bypassing started on the generic side prevents blk-mq from processing new requests but doesn't drain the in-flight ones. This shouldn't break anything but again highlights that something isn't quite right here. The root cause is conflating blk-mq freezing and generic bypassing which are two different mechanisms. The only intersecting purpose that they serve is during queue cleanup. Let's properly separate blk-mq freezing from generic bypassing and simply use it where necessary. * request_queue->mq_freeze_depth is added and blk_mq_[un]freeze_queue() now operate on this counter instead of ->bypass_depth. The replacement for QUEUE_FLAG_BYPASS isn't added but the counter is tested directly. This will be further updated by later changes. * blk_mq_drain_queue() is dropped and "__" prefix is dropped from blk_mq_freeze_queue(). Queue cleanup path now calls blk_mq_freeze_queue() directly. * blk_queue_enter()'s fast path condition is simplified to simply check @q->mq_freeze_depth. Previously, the condition was !blk_queue_dying(q) && (!blk_queue_bypass(q) || !blk_queue_init_done(q)) mq_freeze_depth is incremented right after dying is set and blk_queue_init_done() exception isn't necessary as blk-mq doesn't start frozen, which only leaves the blk_queue_bypass() test which can be replaced by @q->mq_freeze_depth test. This change simplifies the code and reduces confusion in the area. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Nicholas A. Bellinger <nab@linux-iscsi.org> Signed-off-by: Jens Axboe <axboe@fb.com>
* block, blk-mq: draining can't be skipped even if bypass_depth was non-zeroTejun Heo2014-07-011-4/+7
| | | | | | | | | | | | | | | | | | | | | | Currently, both blk_queue_bypass_start() and blk_mq_freeze_queue() skip queue draining if bypass_depth was already above zero. The assumption is that the one which bumped the bypass_depth should have performed draining already; however, there's nothing which prevents a new instance of bypassing/freezing from starting before the previous one finishes draining. The current code may allow the later bypassing/freezing instances to complete while there still are in-flight requests which haven't finished draining. Fix it by draining regardless of bypass_depth. We still skip draining from blk_queue_bypass_start() while the queue is initializing to avoid introducing excessive delays during boot. INIT_DONE setting is moved above the initial blk_queue_bypass_end() so that bypassing attempts can't slip inbetween. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Nicholas A. Bellinger <nab@linux-iscsi.org> Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds2014-06-191-2/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block fixes from Jens Axboe: "A smaller collection of fixes for the block core that would be nice to have in -rc2. This pull request contains: - Fixes for races in the wait/wakeup logic used in blk-mq from Alexander. No issues have been observed, but it is definitely a bit flakey currently. Alternatively, we may drop the cyclic wakeups going forward, but that needs more testing. - Some cleanups from Christoph. - Fix for an oops in null_blk if queue_mode=1 and softirq completions are used. From me. - A fix for a regression caused by the chunk size setting. It inadvertently used max_hw_sectors instead of max_sectors, which is incorrect, and causes hangs on btrfs multi-disk setups (where hw sectors apparently isn't set). From me. - Removal of WQ_POWER_EFFICIENT in the kblockd creation. This was a recent addition as well, but it actually breaks blk-mq which relies on strict scheduling. If the workqueue power_efficient mode is turned on, this breaks blk-mq. From Matias. - null_blk module parameter description fix from Mike" * 'for-linus' of git://git.kernel.dk/linux-block: blk-mq: bitmap tag: fix races in bt_get() function blk-mq: bitmap tag: fix race on blk_mq_bitmap_tags::wake_cnt blk-mq: bitmap tag: fix races on shared ::wake_index fields block: blk_max_size_offset() should check ->max_sectors null_blk: fix softirq completions for queue_mode == 1 blk-mq: merge blk_mq_drain_queue and __blk_mq_drain_queue blk-mq: properly drain stopped queues block: remove WQ_POWER_EFFICIENT from kblockd null_blk: fix name and description of 'queue_mode' module parameter block: remove elv_abort_queue and blk_abort_flushes
| * block: remove WQ_POWER_EFFICIENT from kblockdMatias Bjørling2014-06-111-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blk-mq issues async requests through kblockd. To issue a work request on a specific CPU, kblockd_schedule_delayed_work_on is used. However, the specific CPU choice may not be honored, if the power_efficient option for workqueues is set. blk-mq requires that we have strict per-cpu scheduling, so it wont work properly if kblockd is marked POWER_EFFICIENT and power_efficient is set. Remove the kblockd WQ_POWER_EFFICIENT flag to prevent this behavior. This essentially reverts part of commit 695588f9454b, which added the WQ_POWER_EFFICIENT marker to kblockd. Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
* | Merge git://git.infradead.org/users/willy/linux-nvmeLinus Torvalds2014-06-151-0/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull NVMe update from Matthew Wilcox: "Mostly bugfixes again for the NVMe driver. I'd like to call out the exported tracepoint in the block layer; I believe Keith has cleared this with Jens. We've had a few reports from people who're really pounding on NVMe devices at scale, hence the timeout changes (and new module parameters), hotplug cpu deadlock, tracepoints, and minor performance tweaks" [ Jens hadn't seen that tracepoint thing, but is ok with it - it will end up going away when mq conversion happens ] * git://git.infradead.org/users/willy/linux-nvme: (22 commits) NVMe: Fix START_STOP_UNIT Scsi->NVMe translation. NVMe: Use Log Page constants in SCSI emulation NVMe: Define Log Page constants NVMe: Fix hot cpu notification dead lock NVMe: Rename io_timeout to nvme_io_timeout NVMe: Use last bytes of f/w rev SCSI Inquiry NVMe: Adhere to request queue block accounting enable/disable NVMe: Fix nvme get/put queue semantics NVMe: Delete NVME_GET_FEAT_TEMP_THRESH NVMe: Make admin timeout a module parameter NVMe: Make iod bio timeout a parameter NVMe: Prevent possible NULL pointer dereference NVMe: Fix the buffer size passed in GetLogPage(CDW10.NUMD) NVMe: Update data structures for NVMe 1.2 NVMe: Enable BUILD_BUG_ON checks NVMe: Update namespace and controller identify structures to the 1.1a spec NVMe: Flush with data support NVMe: Configure support for block flush NVMe: Add tracepoints NVMe: Protect against badly formatted CQEs ...
| * NVMe: Add tracepointsKeith Busch2014-05-051-0/+1
| | | | | | | | | | | | | | | | Adding tracepoints for bio_complete and block_split into nvme to help with gathering IO info using blktrace and blkparse. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
* | block: add blk_rq_set_block_pc()Jens Axboe2014-06-061-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the optimizations around not clearing the full request at alloc time, we are leaving some of the needed init for REQ_TYPE_BLOCK_PC up to the user allocating the request. Add a blk_rq_set_block_pc() that sets the command type to REQ_TYPE_BLOCK_PC, and properly initializes the members associated with this type of request. Update callers to use this function instead of manipulating rq->cmd_type directly. Includes fixes from Christoph Hellwig <hch@lst.de> for my half-assed attempt. Signed-off-by: Jens Axboe <axboe@fb.com>
* | block: remove 'magic' from struct blk_plugJens Axboe2014-05-291-5/+0
| | | | | | | | | | | | | | | | I don't think we've ever caught any bugs with this, and there's the list poisoning for the plug lists to catch uninitialized cases. So remove the magic member and save 8 bytes in the struct. Signed-off-by: Jens Axboe <axboe@fb.com>
* | blk-mq: merge blk_mq_alloc_reserved_request into blk_mq_alloc_requestChristoph Hellwig2014-05-281-1/+1
| | | | | | | | | | | | | | | | Instead of having two almost identical copies of the same code just let the callers pass in the reserved flag directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* | block: only allocate/free mq_usage_counter in blk-mqMing Lei2014-05-271-6/+1
| | | | | | | | | | | | | | | | | | The percpu counter is only used for blk-mq, so move its allocation and free inside blk-mq, and don't allocate it for legacy queue device. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | blk-mq: Micro-optimize blk_queue_nomerges() checkRobert Elliott2014-05-201-4/+4
| | | | | | | | | | | | | | | | | | In blk_mq_make_request(), do the blk_queue_nomerges() check outside the call to blk_attempt_plug_merge() to eliminate function call overhead when nomerges=2 (disabled) Signed-off-by: Robert Elliott <elliott@hp.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | blk-mq: allow changing of queue depth through sysfsJens Axboe2014-05-201-0/+41
| | | | | | | | | | | | | | | | | | | | | | For request_fn based devices, the block layer exports a 'nr_requests' file through sysfs to allow adjusting of queue depth on the fly. Currently this returns -EINVAL for blk-mq, since it's not wired up. Wire this up for blk-mq, so that it now also always dynamic adjustments of the allowed queue depth for any given block device managed by blk-mq. Signed-off-by: Jens Axboe <axboe@fb.com>
* | block: only calculate part_in_flight() onceJens Axboe2014-05-091-2/+5
| | | | | | | | | | | | | | | | | | We first check if we have inflight IO, then retrieve that same number again. Usually this isn't that costly since the chance of having the data dirtied in between is small, but there's no reason for calling part_in_flight() twice. Signed-off-by: Jens Axboe <axboe@fb.com>
* | block: export blk_finish_requestChristoph Hellwig2014-04-161-1/+2
| | | | | | | | | | | | | | | | This allows to mirror the blk-mq code flow for more a more readable I/O completion handler in SCSI. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* | blk-mq: add blk_mq_delay_queueChristoph Hellwig2014-04-161-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | Add a blk-mq equivalent to blk_delay_queue so that the scsi layer can ask to be kicked again after a delay. Signed-off-by: Christoph Hellwig <hch@lst.de> Modified by me to kill the unnecessary preempt disable/enable in the delayed workqueue handler. Signed-off-by: Jens Axboe <axboe@fb.com>
* | block: remove struct request buffer memberJens Axboe2014-04-151-15/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This was used in the olden days, back when onions were proper yellow. Basically it mapped to the current buffer to be transferred. With highmem being added more than a decade ago, most drivers map pages out of a bio, and rq->buffer isn't pointing at anything valid. Convert old style drivers to just use bio_data(). For the discard payload use case, just reference the page in the bio. Signed-off-by: Jens Axboe <axboe@fb.com>
* | Merge tag 'v3.15-rc1' into for-3.16/coreJens Axboe2014-04-151-1/+1
|\| | | | | | | | | We don't like this, but things have diverged with the blk-mq fixes in 3.15-rc1. So merge it in.
| * block: fix regression with block enabled taggingJens Axboe2014-04-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Martin reported that his test system would not boot with current git, it oopsed with this: BUG: unable to handle kernel paging request at ffff88046c6c9e80 IP: [<ffffffff812971e0>] blk_queue_start_tag+0x90/0x150 PGD 1ddf067 PUD 1de2067 PMD 47fc7d067 PTE 800000046c6c9060 Oops: 0002 [#1] SMP DEBUG_PAGEALLOC Modules linked in: sd_mod lpfc(+) scsi_transport_fc scsi_tgt oracleasm rpcsec_gss_krb5 ipv6 igb dca i2c_algo_bit i2c_core hwmon CPU: 3 PID: 87 Comm: kworker/u17:1 Not tainted 3.14.0+ #246 Hardware name: Supermicro X9DRX+-F/X9DRX+-F, BIOS 3.00 07/09/2013 Workqueue: events_unbound async_run_entry_fn task: ffff8802743c2150 ti: ffff880273d02000 task.ti: ffff880273d02000 RIP: 0010:[<ffffffff812971e0>] [<ffffffff812971e0>] blk_queue_start_tag+0x90/0x150 RSP: 0018:ffff880273d03a58 EFLAGS: 00010092 RAX: ffff88046c6c9e78 RBX: ffff880077208e78 RCX: 00000000fffc8da6 RDX: 00000000fffc186d RSI: 0000000000000009 RDI: 00000000fffc8d9d RBP: ffff880273d03a88 R08: 0000000000000001 R09: ffff8800021c2410 R10: 0000000000000005 R11: 0000000000015b30 R12: ffff88046c5bb8a0 R13: ffff88046c5c0890 R14: 000000000000001e R15: 000000000000001e FS: 0000000000000000(0000) GS:ffff880277b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88046c6c9e80 CR3: 00000000018f6000 CR4: 00000000000407e0 Stack: ffff880273d03a98 ffff880474b18800 0000000000000000 ffff880474157000 ffff88046c5c0890 ffff880077208e78 ffff880273d03ae8 ffffffff813b9e62 ffff880200000010 ffff880474b18968 ffff880474b18848 ffff88046c5c0cd8 Call Trace: [<ffffffff813b9e62>] scsi_request_fn+0xf2/0x510 [<ffffffff81293167>] __blk_run_queue+0x37/0x50 [<ffffffff8129ac43>] blk_execute_rq_nowait+0xb3/0x130 [<ffffffff8129ad24>] blk_execute_rq+0x64/0xf0 [<ffffffff8108d2b0>] ? bit_waitqueue+0xd0/0xd0 [<ffffffff813bba35>] scsi_execute+0xe5/0x180 [<ffffffff813bbe4a>] scsi_execute_req_flags+0x9a/0x110 [<ffffffffa01b1304>] sd_spinup_disk+0x94/0x460 [sd_mod] [<ffffffff81160000>] ? __unmap_hugepage_range+0x200/0x2f0 [<ffffffffa01b2b9a>] sd_revalidate_disk+0xaa/0x3f0 [sd_mod] [<ffffffffa01b2fb8>] sd_probe_async+0xd8/0x200 [sd_mod] [<ffffffff8107703f>] async_run_entry_fn+0x3f/0x140 [<ffffffff8106a1c5>] process_one_work+0x175/0x410 [<ffffffff8106b373>] worker_thread+0x123/0x400 [<ffffffff8106b250>] ? manage_workers+0x160/0x160 [<ffffffff8107104e>] kthread+0xce/0xf0 [<ffffffff81070f80>] ? kthread_freezable_should_stop+0x70/0x70 [<ffffffff815f0bac>] ret_from_fork+0x7c/0xb0 [<ffffffff81070f80>] ? kthread_freezable_should_stop+0x70/0x70 Code: 48 0f ab 11 72 db 48 81 4b 40 00 00 10 00 89 83 08 01 00 00 48 89 df 49 8b 04 24 48 89 1c d0 e8 f7 a8 ff ff 49 8b 85 28 05 00 00 <48> 89 58 08 48 89 03 49 8d 85 28 05 00 00 48 89 43 08 49 89 9d RIP [<ffffffff812971e0>] blk_queue_start_tag+0x90/0x150 RSP <ffff880273d03a58> CR2: ffff88046c6c9e80 Martin bisected and found this to be the problem patch; commit 6d113398dcf4dfcd9787a4ead738b186f7b7ff0f Author: Jan Kara <jack@suse.cz> Date: Mon Feb 24 16:39:54 2014 +0100 block: Stop abusing rq->csd.list in blk-softirq and the problem was immediately apparent. The patch states that it is safe to reuse queuelist at completion time, since it is no longer used. However, that is not true if a device is using block enabled tagging. If that is the case, then the queuelist is reused to keep track of busy tags. If a device also ended up using softirq completions, we'd reuse ->queuelist for the IPI handling while block tagging was still using it. Boom. Fix this by adding a new ipi_list list head, and share the memory used with the request hash table. The hash table is never used after the request is moved to the dispatch list, which happens long before any potential completion of the request. Add a new request bit for this, so we don't have cases that check rq->hash while it could potentially have been reused for the IPI completion. Reported-by: Martin K. Petersen <martin.petersen@oracle.com> Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Jens Axboe <axboe@fb.com>
* | block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERODuan Jiong2014-04-111-1/+1
| | | | | | | | | | | | | | | | This patch fixes coccinelle error regarding usage of IS_ERR and PTR_ERR instead of PTR_ERR_OR_ZERO. Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | block: add kblockd_schedule_delayed_work_on()Jens Axboe2014-04-091-0/+7
| | | | | | | | | | | | | | | | | | Same function as kblockd_schedule_delayed_work(), but allow the caller to pass in a CPU that the work should be executed on. This just directly extends and maps into the workqueue API, and will be used to make the blk-mq mappings more strict. Signed-off-by: Jens Axboe <axboe@fb.com>
* | block: remove 'q' parameter from kblockd_schedule_*_work()Jens Axboe2014-04-091-3/+3
|/ | | | | | The queue parameter is never used, just get rid of it. Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2014-04-021-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina: "Usual rocket science -- mostly documentation and comment updates" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: sparse: fix comment doc: fix double words isdn: capi: fix "CAPI_VERSION" comment doc: DocBook: Fix typos in xml and template file Bluetooth: add module name for btwilink driver core: unexport static function create_syslog_header mmc: core: typo fix in printk specifier ARM: spear: clean up editing mistake net-sysfs: fix comment typo 'CONFIG_SYFS' doc: Insert MODULE_ in module-signing macros Documentation: update URL to hfsplus Technote 1150 gpio: update path to documentation ixgbe: Fix format string in ixgbe_fcoe. Kconfig: Remove useless "default N" lines user_namespace.c: Remove duplicated word in comment CREDITS: fix formatting treewide: Fix typo in Documentation/DocBook mm: Fix warning on make htmldocs caused by slab.c ata: ata-samsung_cf: cleanup in header file idr: remove unused prototype of idr_free()
| * Merge branch 'master' into for-nextJiri Kosina2014-02-201-26/+55
| |\
| * | treewide: Fix typo in Documentation/DocBookMasanari Iida2014-02-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fix spelling typo in Documentation/DocBook. It is because .html and .xml files are generated by make htmldocs, I have to fix a typo within the source files. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | | Merge branch 'for-3.15/core' of git://git.kernel.dk/linux-blockLinus Torvalds2014-04-011-1/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull core block layer updates from Jens Axboe: "This is the pull request for the core block IO bits for the 3.15 kernel. It's a smaller round this time, it contains: - Various little blk-mq fixes and additions from Christoph and myself. - Cleanup of the IPI usage from the block layer, and associated helper code. From Frederic Weisbecker and Jan Kara. - Duplicate code cleanup in bio-integrity from Gu Zheng. This will give you a merge conflict, but that should be easy to resolve. - blk-mq notify spinlock fix for RT from Mike Galbraith. - A blktrace partial accounting bug fix from Roman Pen. - Missing REQ_SYNC detection fix for blk-mq from Shaohua Li" * 'for-3.15/core' of git://git.kernel.dk/linux-block: (25 commits) blk-mq: add REQ_SYNC early rt,blk,mq: Make blk_mq_cpu_notify_lock a raw spinlock blk-mq: support partial I/O completions blk-mq: merge blk_mq_insert_request and blk_mq_run_request blk-mq: remove blk_mq_alloc_rq blk-mq: don't dump CPU -> hw queue map on driver load blk-mq: fix wrong usage of hctx->state vs hctx->flags blk-mq: allow blk_mq_init_commands() to return failure block: remove old blk_iopoll_enabled variable blktrace: fix accounting of partially completed requests smp: Rename __smp_call_function_single() to smp_call_function_single_async() smp: Remove wait argument from __smp_call_function_single() watchdog: Simplify a little the IPI call smp: Move __smp_call_function_single() below its safe version smp: Consolidate the various smp_call_function_single() declensions smp: Teach __smp_call_function_single() to check for offline cpus smp: Remove unused list_head from csd smp: Iterate functions through llist_for_each_entry_safe() block: Stop abusing rq->csd.list in blk-softirq block: Remove useless IPI struct initialization ...
| * | | blktrace: fix accounting of partially completed requestsRoman Pen2014-03-051-1/+1
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | trace_block_rq_complete does not take into account that request can be partially completed, so we can get the following incorrect output of blkparser: C R 232 + 240 [0] C R 240 + 232 [0] C R 248 + 224 [0] C R 256 + 216 [0] but should be: C R 232 + 8 [0] C R 240 + 8 [0] C R 248 + 8 [0] C R 256 + 8 [0] Also, the whole output summary statistics of completed requests and final throughput will be incorrect. This patch takes into account real completion size of the request and fixes wrong completion accounting. Signed-off-by: Roman Pen <r.peniaev@gmail.com> CC: Steven Rostedt <rostedt@goodmis.org> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Ingo Molnar <mingo@redhat.com> CC: linux-kernel@vger.kernel.org Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
* | | block: free q->flush_rq in blk_init_allocated_queue error pathsDave Jones2014-03-201-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 7982e90c3a57 ("block: fix q->flush_rq NULL pointer crash on dm-mpath flush") moved an allocation to blk_init_allocated_queue(), but neglected to free that allocation on the error paths that follow. Signed-off-by: Dave Jones <davej@fedoraproject.org> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | block: fix q->flush_rq NULL pointer crash on dm-mpath flushMike Snitzer2014-03-081-11/+6
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 1874198 ("blk-mq: rework flush sequencing logic") switched ->flush_rq from being an embedded member of the request_queue structure to being dynamically allocated in blk_init_queue_node(). Request-based DM multipath doesn't use blk_init_queue_node(), instead it uses blk_alloc_queue_node() + blk_init_allocated_queue(). Because commit 1874198 placed the dynamic allocation of ->flush_rq in blk_init_queue_node() any flush issued to a dm-mpath device would crash with a NULL pointer, e.g.: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff8125037e>] blk_rq_init+0x1e/0xb0 PGD bb3c7067 PUD bb01d067 PMD 0 Oops: 0002 [#1] SMP ... CPU: 5 PID: 5028 Comm: dt Tainted: G W O 3.14.0-rc3.snitm+ #10 ... task: ffff88032fb270e0 ti: ffff880079564000 task.ti: ffff880079564000 RIP: 0010:[<ffffffff8125037e>] [<ffffffff8125037e>] blk_rq_init+0x1e/0xb0 RSP: 0018:ffff880079565c98 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000030 RDX: ffff880260c74048 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff880079565ca8 R08: ffff880260aa1e98 R09: 0000000000000001 R10: ffff88032fa78500 R11: 0000000000000246 R12: 0000000000000000 R13: ffff880260aa1de8 R14: 0000000000000650 R15: 0000000000000000 FS: 00007f8d36a2a700(0000) GS:ffff88033fca0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000079b36000 CR4: 00000000000007e0 Stack: 0000000000000000 ffff880260c74048 ffff880079565cd8 ffffffff81257a47 ffff880260aa1de8 ffff880260c74048 0000000000000001 0000000000000000 ffff880079565d08 ffffffff81257c2d 0000000000000000 ffff880260aa1de8 Call Trace: [<ffffffff81257a47>] blk_flush_complete_seq+0x2d7/0x2e0 [<ffffffff81257c2d>] blk_insert_flush+0x1dd/0x210 [<ffffffff8124ec59>] __elv_add_request+0x1f9/0x320 [<ffffffff81250681>] ? blk_account_io_start+0x111/0x190 [<ffffffff81253a4b>] blk_queue_bio+0x25b/0x330 [<ffffffffa0020bf5>] dm_request+0x35/0x40 [dm_mod] [<ffffffff812530c0>] generic_make_request+0xc0/0x100 [<ffffffff81253173>] submit_bio+0x73/0x140 [<ffffffff811becdd>] submit_bio_wait+0x5d/0x80 [<ffffffff81257528>] blkdev_issue_flush+0x78/0xa0 [<ffffffff811c1f6f>] blkdev_fsync+0x3f/0x60 [<ffffffff811b7fde>] vfs_fsync_range+0x1e/0x20 [<ffffffff811b7ffc>] vfs_fsync+0x1c/0x20 [<ffffffff811b81f1>] do_fsync+0x41/0x80 [<ffffffff8118874e>] ? SyS_lseek+0x7e/0x80 [<ffffffff811b8260>] SyS_fsync+0x10/0x20 [<ffffffff8154c2d2>] system_call_fastpath+0x16/0x1b Fix this by moving the ->flush_rq allocation from blk_init_queue_node() to blk_init_allocated_queue(). blk_init_queue_node() also calls blk_init_allocated_queue() so this change is functionality equivalent for all blk_init_queue_node() callers. Reported-by: Hannes Reinecke <hare@suse.de> Reported-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | blk-mq: rework flush sequencing logicChristoph Hellwig2014-02-101-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Witch to using a preallocated flush_rq for blk-mq similar to what's done with the old request path. This allows us to set up the request properly with a tag from the actually allowed range and ->rq_disk as needed by some drivers. To make life easier we also switch to dynamic allocation of ->flush_rq for the old path. This effectively reverts most of "blk-mq: fix for flush deadlock" and "blk-mq: Don't reserve a tag for flush request" Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* | blk-mq: divert __blk_put_request for MQ opsChristoph Hellwig2014-02-071-0/+5
| | | | | | | | | | | | | | | | | | __blk_put_request needs to call into the blk-mq code just like blk_put_request. As we don't have the queue lock in this case both end up calling the same function. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* | block: blk-mq: make blk_sync_queue support mqMing Lei2013-12-311-1/+10
| | | | | | | | | | | | | | | | | | | | This patch moves synchronization on mq->delay_work from blk_mq_free_queue() to blk_sync_queue(), so that blk_sync_queue can work on mq. Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | block: blk-mq: support draining mq queueMing Lei2013-12-311-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | blk_mq_drain_queue() is introduced so that we can drain mq queue inside blk_cleanup_queue(). Also don't accept new requests any more if queue is marked as dying. Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | block: Convert bio_for_each_segment() to bvec_iterKent Overstreet2013-11-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | More prep work for immutable biovecs - with immutable bvecs drivers won't be able to use the biovec directly, they'll need to use helpers that take into account bio->bi_iter.bi_bvec_done. This updates callers for the new usage without changing the implementation yet. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Paul Clements <Paul.Clements@steeleye.com> Cc: Jim Paris <jim@jtan.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com> Cc: Sreekanth Reddy <Sreekanth.Reddy@lsi.com> Cc: support@lsi.com Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Quoc-Son Anh <quoc-sonx.anh@intel.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jan Kara <jack@suse.cz> Cc: linux-m68k@lists.linux-m68k.org Cc: linuxppc-dev@lists.ozlabs.org Cc: drbd-user@lists.linbit.com Cc: nbd-general@lists.sourceforge.net Cc: cbe-oss-dev@lists.ozlabs.org Cc: xen-devel@lists.xensource.com Cc: virtualization@lists.linux-foundation.org Cc: linux-raid@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: DL-MPTFusionLinux@lsi.com Cc: linux-scsi@vger.kernel.org Cc: devel@driverdev.osuosl.org Cc: linux-fsdevel@vger.kernel.org Cc: cluster-devel@redhat.com Cc: linux-mm@kvack.org Acked-by: Geoff Levand <geoff@infradead.org>
* | block: Abstract out bvec iteratorKent Overstreet2013-11-231-18/+18
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Immutable biovecs are going to require an explicit iterator. To implement immutable bvecs, a later patch is going to add a bi_bvec_done member to this struct; for now, this patch effectively just renames things. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Boaz Harrosh <bharrosh@panasas.com> Cc: Benny Halevy <bhalevy@tonian.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <chris.mason@fusionio.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Joern Engel <joern@logfs.org> Cc: Prasad Joshi <prasadjoshi.linux@gmail.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Ben Myers <bpm@sgi.com> Cc: xfs@oss.sgi.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: "Roger Pau Monné" <roger.pau@citrix.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchand@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Peng Tao <tao.peng@emc.com> Cc: Andy Adamson <andros@netapp.com> Cc: fanchaoting <fanchaoting@cn.fujitsu.com> Cc: Jie Liu <jeff.liu@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Pankaj Kumar <pankaj.km@samsung.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Mel Gorman <mgorman@suse.de>6
* Merge branch 'blk-mq/core' into for-3.13/coreJens Axboe2013-11-081-64/+93
|\ | | | | | | | | | | | | Signed-off-by: Jens Axboe <axboe@kernel.dk> Conflicts: block/blk-timeout.c
| * blk-mq: mq plug list breakageShaohua Li2013-10-291-1/+7
| | | | | | | | | | | | | | We switched to plug mq_list for mq, but some code are still using old list. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * blk-mq: fix for flush deadlockChristoph Hellwig2013-10-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The flush state machine takes in a struct request, which then is submitted multiple times to the underling driver. The old block code requeses the same request for each of those, so it does not have an issue with tapping into the request pool. The new one on the other hand allocates a new request for each of the actualy steps of the flush sequence. If have already allocated all of the tags for IO, we will fail allocating the flush request. Set aside a reserved request just for flushes. Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * blk-mq: new multi-queue block IO queueing mechanismJens Axboe2013-10-251-58/+84
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux currently has two models for block devices: - The classic request_fn based approach, where drivers use struct request units for IO. The block layer provides various helper functionalities to let drivers share code, things like tag management, timeout handling, queueing, etc. - The "stacked" approach, where a driver squeezes in between the block layer and IO submitter. Since this bypasses the IO stack, driver generally have to manage everything themselves. With drivers being written for new high IOPS devices, the classic request_fn based driver doesn't work well enough. The design dates back to when both SMP and high IOPS was rare. It has problems with scaling to bigger machines, and runs into scaling issues even on smaller machines when you have IOPS in the hundreds of thousands per device. The stacked approach is then most often selected as the model for the driver. But this means that everybody has to re-invent everything, and along with that we get all the problems again that the shared approach solved. This commit introduces blk-mq, block multi queue support. The design is centered around per-cpu queues for queueing IO, which then funnel down into x number of hardware submission queues. We might have a 1:1 mapping between the two, or it might be an N:M mapping. That all depends on what the hardware supports. blk-mq provides various helper functions, which include: - Scalable support for request tagging. Most devices need to be able to uniquely identify a request both in the driver and to the hardware. The tagging uses per-cpu caches for freed tags, to enable cache hot reuse. - Timeout handling without tracking request on a per-device basis. Basically the driver should be able to get a notification, if a request happens to fail. - Optional support for non 1:1 mappings between issue and submission queues. blk-mq can redirect IO completions to the desired location. - Support for per-request payloads. Drivers almost always need to associate a request structure with some driver private command structure. Drivers can tell blk-mq this at init time, and then any request handed to the driver will have the required size of memory associated with it. - Support for merging of IO, and plugging. The stacked model gets neither of these. Even for high IOPS devices, merging sequential IO reduces per-command overhead and thus increases bandwidth. For now, this is provided as a potential 3rd queueing model, with the hope being that, as it matures, it can replace both the classic and stacked model. That would get us back to having just 1 real model for block devices, leaving the stacked approach to dm/md devices (as it was originally intended). Contributions in this patch from the following people: Shaohua Li <shli@fusionio.com> Alexander Gordeev <agordeev@redhat.com> Christoph Hellwig <hch@infradead.org> Mike Christie <michaelc@cs.wisc.edu> Matias Bjorling <m@bjorling.me> Jeff Moyer <jmoyer@redhat.com> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: remove request ref_countChristoph Hellwig2013-10-251-3/+0
| | | | | | | | | | | | | | | | | | | | This reference count has been around since before git history, but the only place where it's used is in blk_execute_rq, and ther it is entirely useless as it is incremented before submitting the request and decremented in the end_io handler before waking up the submitter thread. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * block: make rq->cmd_flags be 64-bitJens Axboe2013-10-251-2/+2
| | | | | | | | | | | | | | | | We have officially run out of flags in a 32-bit space. Extend it to 64-bit even on 32-bit archs. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | block: Enable sysfs nomerge control for I/O requests in the plug listAlireza Haghdoost2013-11-081-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch enables the sysfs to control I/O request merge functionality in the plug list. While this control has been implemented for the request queue, it was dismissed in the plug list. Therefore, block layer merges requests together (or attempt to merge) even if the merge capability was disable using sysfs nomerge parameter value 2. This limitation is directly affects functionality of io_submit() system call. The system call enables user to submit a bunch of IO requests from user space using struct iocb **ios input argument. However, the unconditioned merging functionality in the plug list potentially merges these requests together down the road. Therefore, there is no way to distinguish between an application sending bunch of sequential IOs and an application sending one big IO. Ultimately, all requests generated by the former app merge within the plug list together and looks similar to the second app. While the merging functionality is a desirable feature to improve the performance of IO subsystem for some applications, it is not useful for other application like ours at all. Signed-off-by: Alireza Haghdoost <alireza@cs.umn.edu> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Coding style modified. Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | elevator: Fix a race in elevator switching and md device initializationTomoki Sekiyama2013-11-081-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The soft lockup below happens at the boot time of the system using dm multipath and the udev rules to switch scheduler. [ 356.127001] BUG: soft lockup - CPU#3 stuck for 22s! [sh:483] [ 356.127001] RIP: 0010:[<ffffffff81072a7d>] [<ffffffff81072a7d>] lock_timer_base.isra.35+0x1d/0x50 ... [ 356.127001] Call Trace: [ 356.127001] [<ffffffff81073810>] try_to_del_timer_sync+0x20/0x70 [ 356.127001] [<ffffffff8118b08a>] ? kmem_cache_alloc_node_trace+0x20a/0x230 [ 356.127001] [<ffffffff810738b2>] del_timer_sync+0x52/0x60 [ 356.127001] [<ffffffff812ece22>] cfq_exit_queue+0x32/0xf0 [ 356.127001] [<ffffffff812c98df>] elevator_exit+0x2f/0x50 [ 356.127001] [<ffffffff812c9f21>] elevator_change+0xf1/0x1c0 [ 356.127001] [<ffffffff812caa50>] elv_iosched_store+0x20/0x50 [ 356.127001] [<ffffffff812d1d09>] queue_attr_store+0x59/0xb0 [ 356.127001] [<ffffffff812143f6>] sysfs_write_file+0xc6/0x140 [ 356.127001] [<ffffffff811a326d>] vfs_write+0xbd/0x1e0 [ 356.127001] [<ffffffff811a3ca9>] SyS_write+0x49/0xa0 [ 356.127001] [<ffffffff8164e899>] system_call_fastpath+0x16/0x1b This is caused by a race between md device initialization by multipathd and shell script to switch the scheduler using sysfs. - multipathd: SyS_ioctl -> do_vfs_ioctl -> dm_ctl_ioctl -> ctl_ioctl -> table_load -> dm_setup_md_queue -> blk_init_allocated_queue -> elevator_init q->elevator = elevator_alloc(q, e); // not yet initialized - sh -c 'echo deadline > /sys/$DEVPATH/queue/scheduler': elevator_switch (in the call trace above) struct elevator_queue *old = q->elevator; q->elevator = elevator_alloc(q, new_e); elevator_exit(old); // lockup! (*) - multipathd: (cont.) err = e->ops.elevator_init_fn(q); // init fails; q->elevator is modified (*) When del_timer_sync() is called, lock_timer_base() will loop infinitely while timer->base == NULL. In this case, as timer will never initialized, it results in lockup. This patch introduces acquisition of q->sysfs_lock around elevator_init() into blk_init_allocated_queue(), to provide mutual exclusion between initialization of the q->scheduler and switching of the scheduler. This should fix this bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=902012 Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | blk-core: Fix memory corruption if blkcg_init_queue failsMikulas Patocka2013-11-081-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If blkcg_init_queue fails, blk_alloc_queue_node doesn't call bdi_destroy to clean up structures allocated by the backing dev. ------------[ cut here ]------------ WARNING: at lib/debugobjects.c:260 debug_print_object+0x85/0xa0() ODEBUG: free active (active state 0) object type: percpu_counter hint: (null) Modules linked in: dm_loop dm_mod ip6table_filter ip6_tables uvesafb cfbcopyarea cfbimgblt cfbfillrect fbcon font bitblit fbcon_rotate fbcon_cw fbcon_ud fbcon_ccw softcursor fb fbdev ipt_MASQUERADE iptable_nat nf_nat_ipv4 msr nf_conntrack_ipv4 nf_defrag_ipv4 xt_state ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc tun ipv6 cpufreq_userspace cpufreq_stats cpufreq_powersave cpufreq_ondemand cpufreq_conservative spadfs fuse hid_generic usbhid hid raid0 md_mod dmi_sysfs nf_nat_ftp nf_nat nf_conntrack_ftp nf_conntrack lm85 hwmon_vid snd_usb_audio snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd_page_alloc snd_hwdep snd_usbmidi_lib snd_rawmidi snd soundcore acpi_cpufreq freq_table mperf sata_svw serverworks kvm_amd ide_core ehci_pci ohci_hcd libata ehci_hcd kvm usbcore tg3 usb_common libphy k10temp pcspkr ptp i2c_piix4 i2c_core evdev microcode hwmon rtc_cmos pps_core e100 skge floppy mii processor button unix CPU: 0 PID: 2739 Comm: lvchange Tainted: G W 3.10.15-devel #14 Hardware name: empty empty/S3992-E, BIOS 'V1.06 ' 06/09/2009 0000000000000009 ffff88023c3c1ae8 ffffffff813c8fd4 ffff88023c3c1b20 ffffffff810399eb ffff88043d35cd58 ffffffff81651940 ffff88023c3c1bf8 ffffffff82479d90 0000000000000005 ffff88023c3c1b80 ffffffff81039a67 Call Trace: [<ffffffff813c8fd4>] dump_stack+0x19/0x1b [<ffffffff810399eb>] warn_slowpath_common+0x6b/0xa0 [<ffffffff81039a67>] warn_slowpath_fmt+0x47/0x50 [<ffffffff8122aaaf>] ? debug_check_no_obj_freed+0xcf/0x250 [<ffffffff81229a15>] debug_print_object+0x85/0xa0 [<ffffffff8122abe3>] debug_check_no_obj_freed+0x203/0x250 [<ffffffff8113c4ac>] kmem_cache_free+0x20c/0x3a0 [<ffffffff811f6709>] blk_alloc_queue_node+0x2a9/0x2c0 [<ffffffff811f672e>] blk_alloc_queue+0xe/0x10 [<ffffffffa04c0093>] dm_create+0x1a3/0x530 [dm_mod] [<ffffffffa04c6bb0>] ? list_version_get_info+0xe0/0xe0 [dm_mod] [<ffffffffa04c6c07>] dev_create+0x57/0x2b0 [dm_mod] [<ffffffffa04c6bb0>] ? list_version_get_info+0xe0/0xe0 [dm_mod] [<ffffffffa04c6bb0>] ? list_version_get_info+0xe0/0xe0 [dm_mod] [<ffffffffa04c6528>] ctl_ioctl+0x268/0x500 [dm_mod] [<ffffffff81097662>] ? get_lock_stats+0x22/0x70 [<ffffffffa04c67ce>] dm_ctl_ioctl+0xe/0x20 [dm_mod] [<ffffffff81161aad>] do_vfs_ioctl+0x2ed/0x520 [<ffffffff8116cfc7>] ? fget_light+0x377/0x4e0 [<ffffffff81161d2b>] SyS_ioctl+0x4b/0x90 [<ffffffff813cff16>] system_call_fastpath+0x1a/0x1f ---[ end trace 4b5ff0d55673d986 ]--- ------------[ cut here ]------------ This fix should be backported to stable kernels starting with 2.6.37. Note that in the kernels prior to 3.5 the affected code is different, but the bug is still there - bdi_init is called and bdi_destroy isn't. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: stable@kernel.org # 2.6.37+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-28 16:38:44 +0000