summaryrefslogtreecommitdiffstats
path: root/block/blk-core.c
Commit message (Collapse)AuthorAgeFilesLines
* block: WARN in __blk_put_request() for potential bio leakBoaz Harrosh2009-03-261-0/+3
| | | | | | | | | | | | | Put a WARN_ON in __blk_put_request if it is about to leak bio(s). This is a serious bug that can happen in error handling code paths. For this to work I have fixed a couple of places in block/ where request->bio != NULL ownership was not honored. And a small cleanup at sg_io() while at it. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: get rid of unused blkdev_free_rq() defineJens Axboe2009-03-241-1/+0
| | | | Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: remove various blk_queue_*() setting functions in blk_init_queue_node()Jens Axboe2009-03-241-6/+3
| | | | | | It calls blk_queue_make_request(), which sets the identical set of limits. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: fix oops in blk_queue_io_stat()Jens Axboe2009-02-021-3/+3
| | | | | | | | Some initial probe requests don't have disk->queue mapped yet, so we can't rely on a non-NULL queue in blk_queue_io_stat(). Wrap it in blk_do_io_stat(). Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: add sysfs file for controlling io stats accountingJens Axboe2009-01-301-36/+54
| | | | | | | This allows us to turn off disk stat accounting completely, for the cases where the 0.5-1% reduction in system time is important. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: silently error an unsupported barrier bioJens Axboe2009-01-301-0/+5
| | | | | | | This fixes a "regression" from 2.6.28, where the barrier probes that file systems may do would trigger additional end request warnings in dmesg. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: seperate bio/request unplug and sync bitsJens Axboe2009-01-301-1/+4
| | | | Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: don't use plugging on SSD devicesJens Axboe2008-12-291-4/+3
| | | | | | | We just want to hand the first bits of IO to the device as fast as possible. Gains a few percent on the IOPS rate. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: remove duplicate or unused barrier/discard error pathsTejun Heo2008-12-291-33/+11
| | | | | | | | | | | | | | | | | | | | | | * Because barrier mode can be changed dynamically, whether barrier is supported or not can be determined only when actually issuing the barrier and there is no point in checking it earlier. Drop barrier support check in generic_make_request() and __make_request(), and update comment around the support check in blk_do_ordered(). * There is no reason to check discard support in both generic_make_request() and __make_request(). Drop the check in __make_request(). While at it, move error action block to the end of the function and add unlikely() to q existence test. * Barrier request, be it empty or not, is never passed to low level driver and thus it's meaningless to try to copy back req->sector to bio->bi_sector on error. In addition, the notion of failed sector doesn't make any sense for empty barrier to begin with. Drop the code block from __end_that_request_first(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: use cancel_work_sync() instead of kblockd_flush_work()Cheng Renquan2008-12-291-7/+1
| | | | | | | | | | | | After many improvements on kblockd_flush_work, it is now identical to cancel_work_sync, so a direct call to cancel_work_sync is suggested. The only difference is that cancel_work_sync is a GPL symbol, so no non-GPL modules anymore. Signed-off-by: Cheng Renquan <crquan@gmail.com> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Supress Buffer I/O errors when SCSI REQ_QUIET flag setKeith Mannthey2008-12-291-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow the scsi request REQ_QUIET flag to be propagated to the buffer file system layer. The basic ideas is to pass the flag from the scsi request to the bio (block IO) and then to the buffer layer. The buffer layer can then suppress needless printks. This patch declutters the kernel log by removed the 40-50 (per lun) buffer io error messages seen during a boot in my multipath setup . It is a good chance any real errors will be missed in the "noise" it the logs without this patch. During boot I see blocks of messages like " __ratelimit: 211 callbacks suppressed Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242847 Buffer I/O error on device sdm, logical block 1 Buffer I/O error on device sdm, logical block 5242878 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242872 " in my logs. My disk environment is multipath fiber channel using the SCSI_DH_RDAC code and multipathd. This topology includes an "active" and "ghost" path for each lun. IO's to the "ghost" path will never complete and the SCSI layer, via the scsi device handler rdac code, quick returns the IOs to theses paths and sets the REQ_QUIET scsi flag to suppress the scsi layer messages. I am wanting to extend the QUIET behavior to include the buffer file system layer to deal with these errors as well. I have been running this patch for a while now on several boxes without issue. A few runs of bonnie++ show no noticeable difference in performance in my setup. Thanks for John Stultz for the quiet_error finalization. Submitted-by: Keith Mannthey <kmannth@us.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: leave the request timeout timer running even on an empty listJens Axboe2008-12-291-0/+1
| | | | | | | | | | | | | For sync IO, we'll often do them serialized. This means we'll be touching the queue timer for every IO, as opposed to only occasionally like we do for queued IO. Instead of deleting the timer when the last request is removed, just let continue running. If a new request comes up soon we then don't have to readd the timer again. If no new requests arrive, the timer will expire without side effect later. This improves high iops sync IO by ~1%. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Merge branches 'tracing/ftrace', 'tracing/function-graph-tracer' and ↵Ingo Molnar2008-12-051-2/+24
|\ | | | | | | 'tracing/urgent' into tracing/core
| * block: fix setting of max_segment_size and seg_boundary maskMilan Broz2008-12-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix setting of max_segment_size and seg_boundary mask for stacked md/dm devices. When stacking devices (LVM over MD over SCSI) some of the request queue parameters are not set up correctly in some cases by default, namely max_segment_size and and seg_boundary mask. If you create MD device over SCSI, these attributes are zeroed. Problem become when there is over this mapping next device-mapper mapping - queue attributes are set in DM this way: request_queue max_segment_size seg_boundary_mask SCSI 65536 0xffffffff MD RAID1 0 0 LVM 65536 -1 (64bit) Unfortunately bio_add_page (resp. bio_phys_segments) calculates number of physical segments according to these parameters. During the generic_make_request() is segment cout recalculated and can increase bio->bi_phys_segments count over the allowed limit. (After bio_clone() in stack operation.) Thi is specially problem in CCISS driver, where it produce OOPS here BUG_ON(creq->nr_phys_segments > MAXSGENTRIES); (MAXSEGENTRIES is 31 by default.) Sometimes even this command is enough to cause oops: dd iflag=direct if=/dev/<vg>/<lv> of=/dev/null bs=128000 count=10 This command generates bios with 250 sectors, allocated in 32 4k-pages (last page uses only 1024 bytes). For LVM layer, it allocates bio with 31 segments (still OK for CCISS), unfortunatelly on lower layer it is recalculated to 32 segments and this violates CCISS restriction and triggers BUG_ON(). The patch tries to fix it by: * initializing attributes above in queue request constructor blk_queue_make_request() * make sure that blk_queue_stack_limits() inherits setting (DM uses its own function to set the limits because it blk_queue_stack_limits() was introduced later. It should probably switch to use generic stack limit function too.) * sets the default seg_boundary value in one place (blkdev.h) * use this mask as default in DM (instead of -1, which differs in 64bit) Bugs related to this: https://bugzilla.redhat.com/show_bug.cgi?id=471639 http://bugzilla.kernel.org/show_bug.cgi?id=8672 Signed-off-by: Milan Broz <mbroz@redhat.com> Reviewed-by: Alasdair G Kergon <agk@redhat.com> Cc: Neil Brown <neilb@suse.de> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Tejun Heo <htejun@gmail.com> Cc: Mike Miller <mike.miller@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * block: internal dequeue shouldn't start timerTejun Heo2008-12-031-1/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blkdev_dequeue_request() and elv_dequeue_request() are equivalent and both start the timeout timer. Barrier code dequeues the original barrier request but doesn't passes the request itself to lower level driver, only broken down proxy requests; however, as the original barrier code goes through the same dequeue path and timeout timer is started on it. If barrier sequence takes long enough, this timer expires but the low level driver has no idea about this request and oops follows. Timeout timer shouldn't have been started on the original barrier request as it never goes through actual IO. This patch unexports elv_dequeue_request(), which has no external user anyway, and makes it operate on elevator proper w/o adding the timer and make blkdev_dequeue_request() call elv_dequeue_request() and add timer. Internal users which don't pass the request to driver - barrier code and end_that_request_last() - are converted to use elv_dequeue_request(). Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | blktrace: port to tracepoints, updateIngo Molnar2008-11-261-0/+13
| | | | | | | | | | | | | | | | | | Port to the new tracepoints API: split DEFINE_TRACE() and DECLARE_TRACE() sites. Spread them out to the usage sites, as suggested by Mathieu Desnoyers. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
* | blktrace: port to tracepointsArnaldo Carvalho de Melo2008-11-261-19/+14
|/ | | | | | | | | | | This was a forward port of work done by Mathieu Desnoyers, I changed it to encode the 'what' parameter on the tracepoint name, so that one can register interest in specific events and not on classes of events to then check the 'what' parameter. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* blk: move blk_delete_timer call in end_that_request_lastMike Anderson2008-11-061-2/+2
| | | | | | | | | | Move the calling blk_delete_timer to later in end_that_request_last to address an issue where blkdev_dequeue_request may have add a timer for the request. Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2008-10-171-5/+21
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.kernel.dk/linux-2.6-block: block: remove __generic_unplug_device() from exports block: move q->unplug_work initialization blktrace: pass zfcp driver data blktrace: add support for driver data block: fix current kernel-doc warnings block: only call ->request_fn when the queue is not stopped block: simplify string handling in elv_iosched_store() block: fix kernel-doc for blk_alloc_devt() block: fix nr_phys_segments miscalculation bug block: add partition attribute for partition number block: add BIG FAT WARNING to CONFIG_DEBUG_BLOCK_EXT_DEVT softirq: Add support for triggering softirq work on softirqs.
| * block: remove __generic_unplug_device() from exportsJens Axboe2008-10-171-1/+0
| | | | | | | | | | | | | | The only out-of-core user is IDE, and that should be using blk_start_queueing() instead. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * block: move q->unplug_work initializationPeter Zijlstra2008-10-171-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | modprobe loop; rmmod loop effectively creates a blk_queue and destroys it which results in q->unplug_work being canceled without it ever being initialized. Therefore, move the initialization of q->unplug_work from blk_queue_make_request() to blk_alloc_queue*(). Reported-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * block: fix current kernel-doc warningsRandy Dunlap2008-10-171-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | Fix block kernel-doc warnings: Warning(linux-2.6.27-git4//fs/block_dev.c:1272): No description found for parameter 'path' Warning(linux-2.6.27-git4//block/blk-core.c:1021): No description found for parameter 'cpu' Warning(linux-2.6.27-git4//block/blk-core.c:1021): No description found for parameter 'part' Warning(/var/linsrc/linux-2.6.27-git4//block/genhd.c:544): No description found for parameter 'partno' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * block: only call ->request_fn when the queue is not stoppedJens Axboe2008-10-171-2/+17
| | | | | | | | | | | | | | | | | | | | | | | | Callers should use either blk_run_queue/__blk_run_queue, or blk_start_queueing() to invoke request handling instead of calling ->request_fn() directly as that does not take the queue stopped flag into account. Also add appropriate comments on the above functions to detail their usage. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | [SCSI] block: separate failfast into multiple bits.Mike Christie2008-10-131-2/+9
|/ | | | | | | | | | | | | | | | | | | | | | Multipath is best at handling transport errors. If it gets a device error then there is not much the multipath layer can do. It will just access the same device but from a different path. This patch breaks up failfast into device, transport and driver errors. The multipath layers (md and dm mutlipath) only ask the lower levels to fast fail transport errors. The user of failfast, read ahead, will ask to fast fail on all errors. Note that blk_noretry_request will return true if any failfast bit is set. This allows drivers that do not support the multipath failfast bits to continue to fail on any failfast error like before. Drivers like scsi that are able to fail fast specific errors can check for the specific fail fast type. In the next patch I will convert scsi. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
* block: remove end_{queued|dequeued}_request()Kiyoshi Ueda2008-10-091-51/+7
| | | | | | | | | | | | | This patch removes end_queued_request() and end_dequeued_request(), which are no longer used. As a results, users of __end_request() became only end_request(). So the actual code in __end_request() is moved to end_request() and __end_request() is removed. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: add lld busy state exporting interfaceKiyoshi Ueda2008-10-091-0/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds an new interface, blk_lld_busy(), to check lld's busy state from the block layer. blk_lld_busy() calls down into low-level drivers for the checking if the drivers set q->lld_busy_fn() using blk_queue_lld_busy(). This resolves a performance problem on request stacking devices below. Some drivers like scsi mid layer stop dispatching request when they detect busy state on its low-level device like host/target/device. It allows other requests to stay in the I/O scheduler's queue for a chance of merging. Request stacking drivers like request-based dm should follow the same logic. However, there is no generic interface for the stacked device to check if the underlying device(s) are busy. If the request stacking driver dispatches and submits requests to the busy underlying device, the requests will stay in the underlying device's queue without a chance of merging. This causes performance problem on burst I/O load. With this patch, busy state of the underlying device is exported via q->lld_busy_fn(). So the request stacking driver can check it and stop dispatching requests if busy. The underlying device driver must return the busy state appropriately: 1: when the device driver can't process requests immediately. 0: when the device driver can process requests immediately, including abnormal situations where the device driver needs to kill all requests. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Fix blk_start_queueing() to not kick a stopped queueElias Oltmanns2008-10-091-2/+4
| | | | | | | | | blk_start_queueing() should act like the generic queue unplugging and kicking and ignore a stopped queue. Such a queue may not be run until after a call to blk_start_queue(). Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: add a queue flag for request stacking supportKiyoshi Ueda2008-10-091-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a queue flag to indicate the block device can be used for request stacking. Request stacking drivers need to stack their devices on top of only devices of which q->request_fn is functional. Since bio stacking drivers (e.g. md, loop) basically initialize their queue using blk_alloc_queue() and don't set q->request_fn, the check of (q->request_fn == NULL) looks enough for that purpose. However, dm will become both types of stacking driver (bio-based and request-based). And dm will always set q->request_fn even if the dm device is bio-based of which q->request_fn is not functional actually. So we need something else to distinguish the type of the device. Adding a queue flag is a solution for that. The reason why dm always sets q->request_fn is to keep the compatibility of dm user-space tools. Currently, all dm user-space tools are using bio-based dm without specifying the type of the dm device they use. To use request-based dm without changing such tools, the kernel must decide the type of the dm device automatically. The automatic type decision can't be done at the device creation time and needs to be deferred until such tools load a mapping table, since the actual type is decided by dm target type included in the mapping table. So a dm device has to be initialized using blk_init_queue() so that we can load either type of table. Then, all queue stuffs are set (e.g. q->request_fn) and we have no element to distinguish that it is bio-based or request-based, even after a table is loaded and the type of the device is decided. By the way, some stuffs of the queue (e.g. request_list, elevator) are needless when the dm device is used as bio-based. But the memory size is not so large (about 20[KB] per queue on ia64), so I hope the memory loss can be acceptable for bio-based dm users. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: add request submission interfaceKiyoshi Ueda2008-10-091-0/+81
| | | | | | | | | | | | | | | | | | This patch adds blk_insert_cloned_request(), a generic request submission interface for request stacking drivers. Request-based dm will use it to submit their clones to underlying devices. blk_rq_check_limits() is also added because it is possible that the lower queue has stronger limitations than the upper queue if multiple drivers are stacking at request-level. Not only for blk_insert_cloned_request()'s internal use, the function will be used by request-based dm when the queue limitation is modified (e.g. by replacing dm's table). Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: add request update interfaceKiyoshi Ueda2008-10-091-9/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds blk_update_request(), which updates struct request with completing its data part, but doesn't complete the struct request itself. Though it looks like end_that_request_first() of older kernels, blk_update_request() should be used only by request stacking drivers. Request-based dm will use it in bio->bi_end_io callback to update the original request when a data part of a cloned request completes. Followings are additional background information of why request-based dm needs this interface. - Request stacking drivers can't use blk_end_request() directly from the lower driver's completion context (bio->bi_end_io or rq->end_io), because some device drivers (e.g. ide) may try to complete their request with queue lock held, and it may cause deadlock. See below for detailed description of possible deadlock: <http://marc.info/?l=linux-kernel&m=120311479108569&w=2> - To solve that, request-based dm offloads the completion of cloned struct request to softirq context (i.e. using blk_complete_request() from rq->end_io). - Though it is possible to use the same solution from bio->bi_end_io, it will delay the notification of bio completion to the original submitter. Also, it will cause inefficient partial completion, because the lower driver can't perform the cloned request anymore and request-based dm needs to requeue and redispatch it to the lower driver again later. That's not good. - So request-based dm needs blk_update_request() to perform the bio completion in the lower driver's completion context, which is more efficient. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: blk_cleanup_queue() should call blk_sync_queue()Jens Axboe2008-10-091-0/+8
| | | | | | | | | When a driver calls blk_cleanup_queue(), the device should be fully idle. However, the block layer may have pending plugging timers and the IO schedulers may have pending work in the work queues. So quisce the device by waiting for the timer and flushing the work queues. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: unify request timeout handlingJens Axboe2008-10-091-0/+7
| | | | | | | | | | | | | Right now SCSI and others do their own command timeout handling. Move those bits to the block layer. Instead of having a timer per command, we try to be a bit more clever and simply have one per-queue. This avoids the overhead of having to tear down and setup a timer for each command, so it will result in a lot less timer fiddling. Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: update comment on end_request()Jens Axboe2008-10-091-3/+3
| | | | | | | It refers to functions that no longer exist after the IO completion changes. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: don't use bio_has_data() in the completion pathJens Axboe2008-10-091-3/+2
| | | | | | | | We should just check for rq->bio, as that is really the information we are looking for. Even if the bio attached doesn't carry data, we still need to do IO post processing on it. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: inherit CPU completion on bio->rq and rq->rq mergesJens Axboe2008-10-091-0/+4
| | | | | | | | | Somewhat incomplete, as we do allow merges of requests and bios that have different completion CPUs given. This is done on the assumption that a larger IO is still more beneficial than CPU locality. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: add support for IO CPU affinityJens Axboe2008-10-091-23/+23
| | | | | | | | | | | | | | | | | | This patch adds support for controlling the IO completion CPU of either all requests on a queue, or on a per-request basis. We export a sysfs variable (rq_affinity) which, if set, migrates completions of requests to the CPU that originally submitted it. A bio helper (bio_set_completion_cpu()) is also added, so that queuers can ask for completion on that specific CPU. In testing, this has been show to cut the system time by as much as 20-40% on synthetic workloads where CPU affinity is desired. This requires a little help from the architecture, so it'll only work as designed for archs that are using the new generic smp helper infrastructure. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: make kblockd_schedule_work() take the queue as parameterJens Axboe2008-10-091-4/+4
| | | | | | Preparatory patch for checking queuing affinity. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: split softirq handling into blk-softirq.cJens Axboe2008-10-091-88/+0
| | | | Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: move stats from disk to part0Tejun Heo2008-10-091-50/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move stats related fields - stamp, in_flight, dkstats - from disk to part0 and unify stat handling such that... * part_stat_*() now updates part0 together if the specified partition is not part0. ie. part_stat_*() are now essentially all_stat_*(). * {disk|all}_stat_*() are gone. * part_round_stats() is updated similary. It handles part0 stats automatically and disk_round_stats() is killed. * part_{inc|dec}_in_fligh() is implemented which automatically updates part0 stats for parts other than part0. * disk_map_sector_rcu() is updated to return part0 if no part matches. Combined with the above changes, this makes NULL special case handling in callers unnecessary. * Separate stats show code paths for disk are collapsed into part stats show code paths. * Rename disk_stat_lock/unlock() to part_stat_lock/unlock() While at it, reposition stat handling macros a bit and add missing parentheses around macro parameters. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: kill GENHD_FL_FAIL and use part0->make_it_failTejun Heo2008-10-091-2/+3
| | | | | | | | GENHD_FL_FAIL for disk is what make_it_fail is for parts. Kill it and use part0->make_it_fail. Sysfs node handling is unified too. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: always set bdev->bd_partTejun Heo2008-10-091-1/+1
| | | | | | | | | Till now, bdev->bd_part is set only if the bdev was for parts other than part0. This patch makes bdev->bd_part always set so that code paths don't have to differenciate common handling. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: fix diskstats accessTejun Heo2008-10-091-25/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two variants of stat functions - ones prefixed with double underbars which don't care about preemption and ones without which disable preemption before manipulating per-cpu counters. It's unclear whether the underbarred ones assume that preemtion is disabled on entry as some callers don't do that. This patch unifies diskstats access by implementing disk_stat_lock() and disk_stat_unlock() which take care of both RCU (for partition access) and preemption (for per-cpu counter access). diskstats access should always be enclosed between the two functions. As such, there's no need for the versions which disables preemption. They're removed and double underbars ones are renamed to drop the underbars. As an extra argument is added, there's no danger of using the old version unconverted. disk_stat_lock() uses get_cpu() and returns the cpu index and all diskstat functions which access per-cpu counters now has @cpu argument to help RT. This change adds RCU or preemption operations at some places but also collapses several preemption ops into one at others. Overall, the performance difference should be negligible as all involved ops are very lightweight per-cpu ones. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: fix disk->part[] dereferencing raceTejun Heo2008-10-091-4/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | disk->part[] is protected by its matching bdev's lock. However, non-critical accesses like collecting stats and printing out sysfs and proc information used to be performed without any locking. As partitions can come and go dynamically, partitions can go away underneath those non-critical accesses. As some of those accesses are writes, this theoretically can lead to silent corruption. This patch fixes the race by using RCU for the partition array and dev reference counter to hold partitions. * Rename disk->part[] to disk->__part[] to make sure no one outside genhd layer proper accesses it directly. * Use RCU for disk->__part[] dereferencing. * Implement disk_{get|put}_part() which can be used to get and put partitions from gendisk respectively. * Iterators are implemented to help iterate through all partitions safely. * Functions which require RCU readlock are marked with _rcu suffix. * Use disk_put_part() in __blkdev_put() instead of directly putting the contained kobject. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: misc updatesTejun Heo2008-10-091-3/+4
| | | | | | | | | | | | | | | | | This patch makes the following misc updates in preparation for disk->part dereference fix and extended block devt support. * implment part_to_disk() * fix comment about gendisk->part indexing * rename get_part() to disk_map_sector() * don't use n which is always zero while printing disk information in diskstats_show() Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Add some block/ source files to the kernel-api docbook. Fix kernel-doc ↵Randy Dunlap2008-10-091-36/+36
| | | | | | | notation in them as needed. Fix changed function parameter names. Fix typos/spellos. In comments, change REQ_SPECIAL to REQ_TYPE_SPECIAL and REQ_BLOCK_PC to REQ_TYPE_BLOCK_PC. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* drop vmerge accountingMikulas Patocka2008-10-091-1/+0
| | | | | | | | Remove hw_segments field from struct bio and struct request. Without virtual merge accounting they have no purpose. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Allow elevators to sort/merge discard requestsDavid Woodhouse2008-10-091-5/+7
| | | | | | | | | | | | | But blkdev_issue_discard() still emits requests which are interpreted as soft barriers, because naïve callers might otherwise issue subsequent writes to those same sectors, which might cross on the queue (if they're reallocated quickly enough). Callers still _can_ issue non-barrier discard requests, but they have to take care of queue ordering for themselves. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Add 'discard' request handlingDavid Woodhouse2008-10-091-8/+20
| | | | | | | | | | | | | | | | | | | | Some block devices benefit from a hint that they can forget the contents of certain sectors. Add basic support for this to the block core, along with a 'blkdev_issue_discard()' helper function which issues such requests. The caller doesn't get to provide an end_io functio, since blkdev_issue_discard() will automatically split the request up into multiple bios if appropriate. Neither does the function wait for completion -- it's expected that callers won't care about when, or even _if_, the request completes. It's only a hint to the device anyway. By definition, the file system doesn't _care_ about these sectors any more. [With feedback from OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> and Jens Axboe <jens.axboe@oracle.com] Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Fix up comments about matching flags between bio and rqDavid Woodhouse2008-10-091-5/+2
| | | | | Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: use bio_has_data() in the IO completion pathJens Axboe2008-10-091-5/+4
| | | | Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-25 06:47:09 +0000