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path: root/include/linux/blkdev.h
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* block: Allow devices to indicate whether discarded blocks are zeroedMartin K. Petersen2009-12-03
| | | | | | | | | | | | | | | | The discard ioctl is used by mkfs utilities to clear a block device prior to putting metadata down. However, not all devices return zeroed blocks after a discard. Some drives return stale data, potentially containing old superblocks. It is therefore important to know whether discarded blocks are properly zeroed. Both ATA and SCSI drives have configuration bits that indicate whether zeroes are returned after a discard operation. Implement a block level interface that allows this information to be bubbled up the stack and queried via a new block device ioctl. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: add helpers to run flush_dcache_page() against a bio and a request's ↵Ilya Loginov2009-11-26
| | | | | | | | | | | | | | | | | | | | | | | | pages Mtdblock driver doesn't call flush_dcache_page for pages in request. So, this causes problems on architectures where the icache doesn't fill from the dcache or with dcache aliases. The patch fixes this. The ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE symbol was introduced to avoid pointless empty cache-thrashing loops on architectures for which flush_dcache_page() is a no-op. Every architecture was provided with this flush pages on architectires where ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE is equal 1 or do nothing otherwise. See "fix mtd_blkdevs problem with caches on some architectures" discussion on LKML for more information. Signed-off-by: Ilya Loginov <isloginov@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Peter Horton <phorton@bitbox.co.uk> Cc: "Ed L. Cashin" <ecashin@coraid.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Expose discard granularityMartin K. Petersen2009-11-10
| | | | | | | | | | While SSDs track block usage on a per-sector basis, RAID arrays often have allocation blocks that are bigger. Allow the discard granularity and alignment to be set and teach the topology stacking logic how to handle them. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: move bdi/address_space unplug functions to backing-dev.hJens Axboe2009-10-29
| | | | | | | | There's nothing block related about them, the backing device is used by things like NFS etc as well. This gets rid of the need to protect such calls by CONFIG_BLOCK. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: get rid of kblock_schedule_delayed_work()Jens Axboe2009-10-05
| | | | | | | | | | It was briefly introduced to allow CFQ to to delayed scheduling, but we ended up removing that feature again. So lets kill the function and export, and just switch CFQ back to the normal work schedule since it is now passing in a '0' delay from all call sites. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Topology ioctlsMartin K. Petersen2009-10-03
| | | | | | | | | | Not all users of the topology information want to use libblkid. Provide the topology information through bdev ioctls. Also clarify sector size comments for existing BLK ioctls. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* cfq-iosched: implement slower async initiate and queue ramp upJens Axboe2009-10-03
| | | | | | | | This slowly ramps up the async queue depth based on the time passed since the sync IO, and doesn't allow async at all until a sync slice period has passed. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: allow large discard requestsChristoph Hellwig2009-10-01
| | | | | | | | | | | | | | | | Currently we set the bio size to the byte equivalent of the blocks to be trimmed when submitting the initial DISCARD ioctl. That means it is subject to the max_hw_sectors limitation of the HBA which is much lower than the size of a DISCARD request we can support. Add a separate max_discard_sectors tunable to limit the size for discard requests. We limit the max discard request size in bytes to 32bit as that is the limit for bio->bi_size. This could be much larger if we had a way to pass that information through the block layer. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: use normal I/O path for discard requestsChristoph Hellwig2009-10-01
| | | | | | | | | | | | | | | | | | | | | | | | prepare_discard_fn() was being called in a place where memory allocation was effectively impossible. This makes it inappropriate for all but the most trivial translations of Linux's DISCARD operation to the block command set. Additionally adding a payload there makes the ownership of the bio backing unclear as it's now allocated by the device driver and not the submitter as usual. It is replaced with QUEUE_FLAG_DISCARD which is used to indicate whether the queue supports discard operations or not. blkdev_issue_discard now allocates a one-page, sector-length payload which is the right thing for the common ATA and SCSI implementations. The mtd implementation of prepare_discard_fn() is replaced with simply checking for the request being a discard. Largely based on a previous patch from Matthew Wilcox <matthew@wil.cx> which did the prepare_discard_fn but not the different payload allocation yet. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: use blkdev_issue_discard in blk_ioctl_discardChristoph Hellwig2009-09-14
| | | | | | | | | | | | | | | blk_ioctl_discard duplicates large amounts of code from blkdev_issue_discard, the only difference between the two is that blkdev_issue_discard needs to send a barrier discard request and blk_ioctl_discard a non-barrier one, and blk_ioctl_discard needs to wait on the request. To facilitates this add a flags argument to blkdev_issue_discard to control both aspects of the behaviour. This will be very useful later on for using the waiting funcitonality for other callers. Based on an earlier patch from Matthew Wilcox <matthew@wil.cx>. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Optimal I/O limit wrapperMartin K. Petersen2009-09-14
| | | | | | | | | Implement blk_limits_io_opt() and make blk_queue_io_opt() a wrapper around it. DM needs this to avoid poking at the queue_limits directly. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: enable rq CPU completion affinity by defaultJens Axboe2009-09-11
| | | | | | | | Test results here look good, and on big OLTP runs it has also shown to significantly increase cycles attributed to the database and cause a performance boost. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: improve queue_should_plug() by looking at IO depthsJens Axboe2009-09-11
| | | | | | | | | | | | | Instead of just checking whether this device uses block layer tagging, we can improve the detection by looking at the maximum queue depth it has reached. If that crosses 4, then deem it a queuing device. This is important on high IOPS devices, since plugging hurts the performance there (it can be as much as 10-15% of the sys time). Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* bio: first step in sanitizing the bio->bi_rw flag testingJens Axboe2009-09-11
| | | | | | | | Get rid of any functions that test for these bits and make callers use bio_rw_flagged() directly. Then it is at least directly apparent what variable and flag they check. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: implement mixed merge of different failfast requestsTejun Heo2009-09-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Failfast has characteristics from other attributes. When issuing, executing and successuflly completing requests, failfast doesn't make any difference. It only affects how a request is handled on failure. Allowing requests with different failfast settings to be merged cause normal IOs to fail prematurely while not allowing has performance penalties as failfast is used for read aheads which are likely to be located near in-flight or to-be-issued normal IOs. This patch introduces the concept of 'mixed merge'. A request is a mixed merge if it is merge of segments which require different handling on failure. Currently the only mixable attributes are failfast ones (or lack thereof). When a bio with different failfast settings is added to an existing request or requests of different failfast settings are merged, the merged request is marked mixed. Each bio carries failfast settings and the request always tracks failfast state of the first bio. When the request fails, blk_rq_err_bytes() can be used to determine how many bytes can be safely failed without crossing into an area which requires further retrials. This allows request merging regardless of failfast settings while keeping the failure handling correct. This patch only implements mixed merge but doesn't enable it. The next one will update SCSI to make use of mixed merge. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Niel Lambrechts <niel.lambrechts@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: use the same failfast bits for bio and requestTejun Heo2009-09-11
| | | | | | | | | | | | | | | | | | | | bio and request use the same set of failfast bits. This patch makes the following changes to simplify things. * enumify BIO_RW* bits and reorder bits such that BIOS_RW_FAILFAST_* bits coincide with __REQ_FAILFAST_* bits. * The above pushes BIO_RW_AHEAD out of sync with __REQ_FAILFAST_DEV but the matching is useless anyway. init_request_from_bio() is responsible for setting FAILFAST bits on FS requests and non-FS requests never use BIO_RW_AHEAD. Drop the code and comment from blk_rq_bio_prep(). * Define REQ_FAILFAST_MASK which is OR of all FAILFAST bits and simplify FAILFAST flags handling in init_request_from_bio(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Add a wrapper for setting minimum request size without a queueMartin K. Petersen2009-08-01
| | | | | | | | Introduce blk_limits_io_min() and make blk_queue_io_min() call it. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Fix compile error due to congestion_wait() changesTrond Myklebust2009-07-11
| | | | | | | | | | | | | | Move the definition of BLK_RW_ASYNC/BLK_RW_SYNC into linux/backing-dev.h so that it is available to all callers of set/clear_bdi_congested(). This replaces commit 097041e576ee3a50d92dd643ee8ca65bf6a62e21 ("fuse: Fix build error"), which will be reverted. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Larry Finger <Larry.Finger@lwfinger.net> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block: fix sg SG_DXFER_TO_FROM_DEV regressionFUJITA Tomonori2009-07-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I overlooked SG_DXFER_TO_FROM_DEV support when I converted sg to use the block layer mapping API (2.6.28). Douglas Gilbert explained SG_DXFER_TO_FROM_DEV: http://www.spinics.net/lists/linux-scsi/msg37135.html = The semantics of SG_DXFER_TO_FROM_DEV were: - copy user space buffer to kernel (LLD) buffer - do SCSI command which is assumed to be of the DATA_IN (data from device) variety. This would overwrite some or all of the kernel buffer - copy kernel (LLD) buffer back to the user space. The idea was to detect short reads by filling the original user space buffer with some marker bytes ("0xec" it would seem in this report). The "resid" value is a better way of detecting short reads but that was only added this century and requires co-operation from the LLD. = This patch changes the block layer mapping API to support this semantics. This simply adds another field to struct rq_map_data and enables __bio_copy_iov() to copy data from user space even with READ requests. It's better to add the flags field and kills null_mapped and the new from_user fields in struct rq_map_data but that approach makes it difficult to send this patch to stable trees because st and osst drivers use struct rq_map_data (they were converted to use the block layer in 2.6.29 and 2.6.30). Well, I should clean up the block layer mapping API. zhou sf reported this regiression and tested this patch: http://www.spinics.net/lists/linux-scsi/msg37128.html http://www.spinics.net/lists/linux-scsi/msg37168.html Reported-by: zhou sf <sxzzsf@gmail.com> Tested-by: zhou sf <sxzzsf@gmail.com> Cc: stable@kernel.org Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Fix congestion_wait() sync/async vs read/write confusionJens Axboe2009-07-10
| | | | | | | | Commit 1faa16d22877f4839bd433547d770c676d1d964c accidentally broke the bdi congestion wait queue logic, causing us to wait on congestion for WRITE (== 1) when we really wanted BLK_RW_ASYNC (== 0) instead. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: get rid of queue-private command filterJens Axboe2009-07-01
| | | | | | | | | | The initial patches to support this through sysfs export were broken and have been if 0'ed out in any release. So lets just kill the code and reclaim some space in struct request_queue, if anyone would later like to fixup the sysfs bits, the git history can easily restore the removed bits. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Introduce helper to reset queue limits to default valuesMartin K. Petersen2009-06-16
| | | | | | | | | | | DM reuses the request queue when swapping in a new device table Introduce blk_set_default_limits() which can be used to reset the the queue_limits prior to stacking devices. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Alasdair G Kergon <agk@redhat.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Merge branch 'for-2.6.31' of ↵Linus Torvalds2009-06-12
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6 * 'for-2.6.31' of git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: (29 commits) ide: re-implement ide_pci_init_one() on top of ide_pci_init_two() ide: unexport ide_find_dma_mode() ide: fix PowerMac bootup oops ide: skip probe if there are no devices on the port (v2) sl82c105: add printk() logging facility ide-tape: fix proc warning ide: add IDE_DFLAG_NIEN_QUIRK device flag ide: respect quirk_drives[] list on all controllers hpt366: enable all quirks for devices on quirk_drives[] list hpt366: sync quirk_drives[] list with pdc202xx_{new,old}.c ide: remove superfluous SELECT_MASK() call from do_rw_taskfile() ide: remove superfluous SELECT_MASK() call from ide_driveid_update() icside: remove superfluous ->maskproc method ide-tape: fix IDE_AFLAG_* atomic accesses ide-tape: change IDE_AFLAG_IGNORE_DSC non-atomically pdc202xx_old: kill resetproc() method pdc202xx_old: don't call pdc202xx_reset() on IRQ timeout pdc202xx_old: use ide_dma_test_irq() ide: preserve Host Protected Area by default (v2) ide-gd: implement block device ->set_capacity method (v2) ...
| * partitions: add ->set_capacity block device methodBartlomiej Zolnierkiewicz2009-06-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Add ->set_capacity block device method and use it in rescan_partitions() to attempt enabling native capacity of the device upon detecting the partition which exceeds device capacity. * Add GENHD_FL_NATIVE_CAPACITY flag to try limit attempts of enabling native capacity during partition scan. Together with the consecutive patch implementing ->set_capacity method in ide-gd device driver this allows automatic disabling of Host Protected Area (HPA) if any partitions overlapping HPA are detected. Cc: Robert Hancock <hancockrwd@gmail.com> Cc: Frans Pop <elendil@planet.nl> Cc: "Andries E. Brouwer" <Andries.Brouwer@cwi.nl> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Emphatically-Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* | block: add request clone interface (v2)Kiyoshi Ueda2009-06-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the following 2 interfaces for request-stacking drivers: - blk_rq_prep_clone(struct request *clone, struct request *orig, struct bio_set *bs, gfp_t gfp_mask, int (*bio_ctr)(struct bio *, struct bio*, void *), void *data) * Clones bios in the original request to the clone request (bio_ctr is called for each cloned bios.) * Copies attributes of the original request to the clone request. The actual data parts (e.g. ->cmd, ->buffer, ->sense) are not copied. - blk_rq_unprep_clone(struct request *clone) * Frees cloned bios from the clone request. Request stacking drivers (e.g. request-based dm) need to make a clone request for a submitted request and dispatch it to other devices. To allocate request for the clone, request stacking drivers may not be able to use blk_get_request() because the allocation may be done in an irq-disabled context. So blk_rq_prep_clone() takes a request allocated by the caller as an argument. For each clone bio in the clone request, request stacking drivers should be able to set up their own completion handler. So blk_rq_prep_clone() takes a callback function which is called for each clone bio, and a pointer for private data which is passed to the callback. NOTE: blk_rq_prep_clone() doesn't copy any actual data of the original request. Pages are shared between original bios and cloned bios. So caller must not complete the original request before the clone request. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | Revert "block: Fix bounce limit setting in DM"Jens Axboe2009-06-09
| | | | | | | | | | | | | | | | This reverts commit a05c0205ba031c01bba33a21bf0a35920eb64833. DM doesn't need to access the bounce_pfn directly. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | block: Fix bounce limit setting in DMMartin K. Petersen2009-06-03
| | | | | | | | | | | | | | | | | | | | blk_queue_bounce_limit() is more than a wrapper about the request queue limits.bounce_pfn variable. Introduce blk_queue_bounce_pfn() which can be called by stacking drivers that wish to set the bounce limit explicitly. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | block: Export I/O topology for block devices and partitionsMartin K. Petersen2009-05-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To support devices with physical block sizes bigger than 512 bytes we need to ensure proper alignment. This patch adds support for exposing I/O topology characteristics as devices are stacked. logical_block_size is the smallest unit the device can address. physical_block_size indicates the smallest I/O the device can write without incurring a read-modify-write penalty. The io_min parameter is the smallest preferred I/O size reported by the device. In many cases this is the same as the physical block size. However, the io_min parameter can be scaled up when stacking (RAID5 chunk size > physical block size). The io_opt characteristic indicates the optimal I/O size reported by the device. This is usually the stripe width for arrays. The alignment_offset parameter indicates the number of bytes the start of the device/partition is offset from the device's natural alignment. Partition tools and MD/DM utilities can use this to pad their offsets so filesystems start on proper boundaries. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | block: Move queue limits to an embedded structMartin K. Petersen2009-05-22
| | | | | | | | | | | | | | | | To accommodate stacking drivers that do not have an associated request queue we're moving the limits to a separate, embedded structure. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | block: Use accessor functions for queue limitsMartin K. Petersen2009-05-22
| | | | | | | | | | | | | | | | Convert all external users of queue limits to using wrapper functions instead of poking the request queue variables directly. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | block: Do away with the notion of hardsect_sizeMartin K. Petersen2009-05-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Until now we have had a 1:1 mapping between storage device physical block size and the logical block sized used when addressing the device. With SATA 4KB drives coming out that will no longer be the case. The sector size will be 4KB but the logical block size will remain 512-bytes. Hence we need to distinguish between the physical block size and the logical ditto. This patch renames hardsect_size to logical_block_size. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | Merge branch 'master' into for-2.6.31Jens Axboe2009-05-22
|\ \ | | | | | | | | | | | | | | | | | | | | | Conflicts: drivers/block/hd.c drivers/block/mg_disk.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | Merge branch 'for-linus' of ↵Linus Torvalds2009-05-02
| |\| | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: ide-cd: fix REQ_QUIET tests in cdrom_decode_status Fix up trivial conflicts in include/linux/blkdev.h
| | * ide-cd: fix REQ_QUIET tests in cdrom_decode_statusBorislav Petkov2009-04-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Original patch (dfa4411cc3a690011cab90e9a536938795366cf9) was buggy. This is a more proper fix which introduces blk_rq_quiet() macro alleviating the need for dumb, too short caching variables. Thanks to Helge Deller and Bart for debugging this. Signed-off-by: Borislav Petkov <petkovbb@gmail.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com> Reported-and-tested-by: Helge Deller <deller@gmx.de> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* | | block: change the tag sync vs async restriction logicJens Axboe2009-05-20
| | | | | | | | | | | | | | | | | | | | | Make them fully share the tag space, but disallow async requests using the last any two slots. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | block: Un-export blk_rq_append_bioBoaz Harrosh2009-05-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | OSD was the last in-tree user of blk_rq_append_bio(). Now that it is fixed blk_rq_append_bio is un-exported and is only used internally by block layer. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | block: Add blk_make_request(), takes bio, returns a requestBoaz Harrosh2009-05-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | New block API: given a struct bio allocates a new request. This is the parallel of generic_make_request for BLOCK_PC commands users. The passed bio may be a chained-bio. The bio is bounced if needed inside the call to this member. This is in the effort of un-exporting blk_rq_append_bio(). Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> CC: Jeff Garzik <jeff@garzik.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | block: move completion related functions back to blk-core.cFUJITA Tomonori2009-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | Let's put the completion related functions back to block/blk-core.c where they have lived. We can also unexport blk_end_bidi_request() and __blk_end_bidi_request(), which nobody uses. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | block: let blk_end_request_all handle bidi requestsFUJITA Tomonori2009-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blk_end_request_all() and __blk_end_request_all() should finish all bytes including bidi, by definition. That's what all bidi users need , bidi requests must be complete as a whole (partial completion is impossible). Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | block: implement and enforce request peek/start/fetchTejun Heo2009-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Till now block layer allowed two separate modes of request execution. A request is always acquired from the request queue via elv_next_request(). After that, drivers are free to either dequeue it or process it without dequeueing. Dequeue allows elv_next_request() to return the next request so that multiple requests can be in flight. Executing requests without dequeueing has its merits mostly in allowing drivers for simpler devices which can't do sg to deal with segments only without considering request boundary. However, the benefit this brings is dubious and declining while the cost of the API ambiguity is increasing. Segment based drivers are usually for very old or limited devices and as converting to dequeueing model isn't difficult, it doesn't justify the API overhead it puts on block layer and its more modern users. Previous patches converted all block low level drivers to dequeueing model. This patch completes the API transition by... * renaming elv_next_request() to blk_peek_request() * renaming blkdev_dequeue_request() to blk_start_request() * adding blk_fetch_request() which is combination of peek and start * disallowing completion of queued (not started) requests * applying new API to all LLDs Renamings are for consistency and to break out of tree code so that it's apparent that out of tree drivers need updating. [ Impact: block request issue API cleanup, no functional change ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Mike Miller <mike.miller@hp.com> Cc: unsik Kim <donari75@gmail.com> Cc: Paul Clements <paul.clements@steeleye.com> Cc: Tim Waugh <tim@cyberelk.net> Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Cc: David S. Miller <davem@davemloft.net> Cc: Laurent Vivier <Laurent@lvivier.info> Cc: Jeff Garzik <jgarzik@pobox.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Adrian McMenamin <adrian@mcmen.demon.co.uk> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Borislav Petkov <petkovbb@googlemail.com> Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: Pierre Ossman <drzeus@drzeus.cx> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Markus Lidel <Markus.Lidel@shadowconnect.com> Cc: Stefan Weinhuber <wein@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pete Zaitcev <zaitcev@redhat.com> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | block: hide request sector and data_lenTejun Heo2009-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Block low level drivers for some reason have been pretty good at abusing block layer API. Especially struct request's fields tend to get violated in all possible ways. Make it clear that low level drivers MUST NOT access or manipulate rq->sector and rq->data_len directly by prefixing them with double underscores. This change is also necessary to break build of out-of-tree codes which assume the previous block API where internal fields can be manipulated and rq->data_len carries residual count on completion. [ Impact: hide internal fields, block API change ] Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | block: drop request->hard_* and *nr_sectorsTejun Heo2009-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | struct request has had a few different ways to represent some properties of a request. ->hard_* represent block layer's view of the request progress (completion cursor) and the ones without the prefix are supposed to represent the issue cursor and allowed to be updated as necessary by the low level drivers. The thing is that as block layer supports partial completion, the two cursors really aren't necessary and only cause confusion. In addition, manual management of request detail from low level drivers is cumbersome and error-prone at the very least. Another interesting duplicate fields are rq->[hard_]nr_sectors and rq->{hard_cur|current}_nr_sectors against rq->data_len and rq->bio->bi_size. This is more convoluted than the hard_ case. rq->[hard_]nr_sectors are initialized for requests with bio but blk_rq_bytes() uses it only for !pc requests. rq->data_len is initialized for all request but blk_rq_bytes() uses it only for pc requests. This causes good amount of confusion throughout block layer and its drivers and determining the request length has been a bit of black magic which may or may not work depending on circumstances and what the specific LLD is actually doing. rq->{hard_cur|current}_nr_sectors represent the number of sectors in the contiguous data area at the front. This is mainly used by drivers which transfers data by walking request segment-by-segment. This value always equals rq->bio->bi_size >> 9. However, data length for pc requests may not be multiple of 512 bytes and using this field becomes a bit confusing. In general, having multiple fields to represent the same property leads only to confusion and subtle bugs. With recent block low level driver cleanups, no driver is accessing or manipulating these duplicate fields directly. Drop all the duplicates. Now rq->sector means the current sector, rq->data_len the current total length and rq->bio->bi_size the current segment length. Everything else is defined in terms of these three and available only through accessors. * blk_recalc_rq_sectors() is collapsed into blk_update_request() and now handles pc and fs requests equally other than rq->sector update. This means that now pc requests can use partial completion too (no in-kernel user yet tho). * bio_cur_sectors() is replaced with bio_cur_bytes() as block layer now uses byte count as the primary data length. * blk_rq_pos() is now guranteed to be always correct. In-block users converted. * blk_rq_bytes() is now guaranteed to be always valid as is blk_rq_sectors(). In-block users converted. * blk_rq_sectors() is now guaranteed to equal blk_rq_bytes() >> 9. More convenient one is used. * blk_rq_bytes() and blk_rq_cur_bytes() are now inlined and take const pointer to request. [ Impact: API cleanup, single way to represent one property of a request ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | block: implement blk_rq_pos/[cur_]sectors() and convert obvious onesTejun Heo2009-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement accessors - blk_rq_pos(), blk_rq_sectors() and blk_rq_cur_sectors() which return rq->hard_sector, rq->hard_nr_sectors and rq->hard_cur_sectors respectively and convert direct references of the said fields to the accessors. This is in preparation of request data length handling cleanup. Geert : suggested adding const to struct request * parameter to accessors Sergei : spotted error in patch description [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Acked-by: Stephen Rothwell <sfr@canb.auug.org.au> Tested-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Grant Likely <grant.likely@secretlab.ca> Ackec-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Borislav Petkov <petkovbb@googlemail.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | block: add rq->resid_lenTejun Heo2009-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rq->data_len served two purposes - the length of data buffer on issue and the residual count on completion. This duality creates some headaches. First of all, block layer and low level drivers can't really determine what rq->data_len contains while a request is executing. It could be the total request length or it coulde be anything else one of the lower layers is using to keep track of residual count. This complicates things because blk_rq_bytes() and thus [__]blk_end_request_all() relies on rq->data_len for PC commands. Drivers which want to report residual count should first cache the total request length, update rq->data_len and then complete the request with the cached data length. Secondly, it makes requests default to reporting full residual count, ie. reporting that no data transfer occurred. The residual count is an exception not the norm; however, the driver should clear rq->data_len to zero to signify the normal cases while leaving it alone means no data transfer occurred at all. This reverse default behavior complicates code unnecessarily and renders block PC on some drivers (ide-tape/floppy) unuseable. This patch adds rq->resid_len which is used only for residual count. While at it, remove now unnecessasry blk_rq_bytes() caching in ide_pc_intr() as rq->data_len is not changed anymore. Boaz : spotted missing conversion in osd Sergei : spotted too early conversion to blk_rq_bytes() in ide-tape [ Impact: cleanup residual count handling, report 0 resid by default ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Borislav Petkov <petkovbb@googlemail.com> Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com> Cc: Mike Miller <mike.miller@hp.com> Cc: Eric Moore <Eric.Moore@lsi.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: Mike Miller <mike.miller@hp.com> Cc: Eric Moore <Eric.Moore@lsi.com> Cc: Darrick J. Wong <djwong@us.ibm.com> Cc: Pete Zaitcev <zaitcev@redhat.com> Cc: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | block: make blk_end_request_cur() return boolTejun Heo2009-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the process of mindlessly copying [__]blk_end_request_all(), [__]blk_end_request_cur() ended up returning void even though they're partial completion functions. Fix it. [ Impact: fix braindead API ] Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | block: kill rq->dataTejun Heo2009-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that all block request data transfer is done via bio, rq->data isn't used. Kill it. While at it, make the roles of rq->special and buffer clear. [ Impact: drop now unncessary field from struct request ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Boaz Harrosh <bharrosh@panasas.com>
* | | block: replace end_request() with [__]blk_end_request_cur()Tejun Heo2009-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | end_request() has been kept around for backward compatibility; however, it's about time for it to go away. * There aren't too many users left. * Its use of @updtodate is pretty confusing. * In some cases, newer code ends up using mixture of end_request() and [__]blk_end_request[_all](), which is way too confusing. So, add [__]blk_end_request_cur() and replace end_request() with it. Most conversions are straightforward. Noteworthy ones are... * paride/pcd: next_request() updated to take 0/-errno instead of 1/0. * paride/pf: pf_end_request() and next_request() updated to take 0/-errno instead of 1/0. * xd: xd_readwrite() updated to return 0/-errno instead of 1/0. * mtd/mtd_blkdevs: blktrans_discard_request() updated to return 0/-errno instead of 1/0. Unnecessary local variable res initialization removed from mtd_blktrans_thread(). [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Joerg Dorchain <joerg@dorchain.net> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Laurent Vivier <Laurent@lvivier.info> Cc: Tim Waugh <tim@cyberelk.net> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Markus Lidel <Markus.Lidel@shadowconnect.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Pete Zaitcev <zaitcev@redhat.com> Cc: unsik Kim <donari75@gmail.com>
* | | block: implement and use [__]blk_end_request_all()Tejun Heo2009-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are many [__]blk_end_request() call sites which call it with full request length and expect full completion. Many of them ensure that the request actually completes by doing BUG_ON() the return value, which is awkward and error-prone. This patch adds [__]blk_end_request_all() which takes @rq and @error and fully completes the request. BUG_ON() is added to to ensure that this actually happens. Most conversions are simple but there are a few noteworthy ones. * cdrom/viocd: viocd_end_request() replaced with direct calls to __blk_end_request_all(). * s390/block/dasd: dasd_end_request() replaced with direct calls to __blk_end_request_all(). * s390/char/tape_block: tapeblock_end_request() replaced with direct calls to blk_end_request_all(). [ Impact: cleanup ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Mike Miller <mike.miller@hp.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Jeff Garzik <jgarzik@pobox.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Alex Dubov <oakad@yahoo.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
* | | block: clean up request completion APITejun Heo2009-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Request completion has gone through several changes and became a bit messy over the time. Clean it up. 1. end_that_request_data() is a thin wrapper around end_that_request_data_first() which checks whether bio is NULL before doing anything and handles bidi completion. blk_update_request() is a thin wrapper around end_that_request_data() which clears nr_sectors on the last iteration but doesn't use the bidi completion. Clean it up by moving the initial bio NULL check and nr_sectors clearing on the last iteration into end_that_request_data() and renaming it to blk_update_request(), which makes blk_end_io() the only user of end_that_request_data(). Collapse end_that_request_data() into blk_end_io(). 2. There are four visible completion variants - blk_end_request(), __blk_end_request(), blk_end_bidi_request() and end_request(). blk_end_request() and blk_end_bidi_request() uses blk_end_request() as the backend but __blk_end_request() and end_request() use separate implementation in __blk_end_request() due to different locking rules. blk_end_bidi_request() is identical to blk_end_io(). Collapse blk_end_io() into blk_end_bidi_request(), separate out request update into internal helper blk_update_bidi_request() and add __blk_end_bidi_request(). Redefine [__]blk_end_request() as thin inline wrappers around [__]blk_end_bidi_request(). 3. As the whole request issue/completion usages are about to be modified and audited, it's a good chance to convert completion functions return bool which better indicates the intended meaning of return values. 4. The function name end_that_request_last() is from the days when it was a public interface and slighly confusing. Give it a proper internal name - blk_finish_request(). 5. Add description explaning that blk_end_bidi_request() can be safely used for uni requests as suggested by Boaz Harrosh. The only visible behavior change is from #1. nr_sectors counts are cleared after the final iteration no matter which function is used to complete the request. I couldn't find any place where the code assumes those nr_sectors counters contain the values for the last segment and this change is good as it makes the API much more consistent as the end result is now same whether a request is completed using [__]blk_end_request() alone or in combination with blk_update_request(). API further cleaned up per Christoph's suggestion. [ Impact: cleanup, rq->*nr_sectors always updated after req completion ] Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Boaz Harrosh <bharrosh@panasas.com> Cc: Christoph Hellwig <hch@infradead.org>
* | | block: kill blk_end_request_callback()Tejun Heo2009-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | With recent IDE updates, blk_end_request_callback() doesn't have any user now. Kill it. [ Impact: removal of unused convoluted interface ] Signed-off-by: Tejun Heo <tj@kernel.org>
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-30 11:00:46 -0500