aboutsummaryrefslogtreecommitdiff
path: root/block/ll_rw_blk.c
AgeCommit message (Collapse)Author
2008-01-28blk_end_request: changing block layer core (take 4)Kiyoshi Ueda
This patch converts core parts of block layer to use blk_end_request interfaces. Related 'uptodate' arguments are converted to 'error'. 'dequeue' argument was originally introduced for end_dequeued_request(), where no attempt should be made to dequeue the request as it's already dequeued. However, it's not necessary as it can be checked with list_empty(&rq->queuelist). (Dequeued request has empty list and queued request doesn't.) And it has been done in blk_end_request interfaces. As a result of this patch, end_queued_request() and end_dequeued_request() become identical. A future patch will merge and rename them and change users of those functions. 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>
2008-01-28blk_end_request: add/export functions to get request size (take 4)Kiyoshi Ueda
This patch adds/exports functions to get the size of request in bytes. They are useful because blk_end_request interfaces take bytes as a completed I/O size instead of sectors. 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>
2008-01-28blk_end_request: add new request completion interface (take 4)Kiyoshi Ueda
This patch adds 2 new interfaces for request completion: o blk_end_request() : called without queue lock o __blk_end_request() : called with queue lock held blk_end_request takes 'error' as an argument instead of 'uptodate', which current end_that_request_* take. The meanings of values are below and the value is used when bio is completed. 0 : success < 0 : error Some device drivers call some generic functions below between end_that_request_{first/chunk} and end_that_request_last(). o add_disk_randomness() o blk_queue_end_tag() o blkdev_dequeue_request() These are called in the blk_end_request interfaces as a part of generic request completion. So all device drivers become to call above functions. To decide whether to call blkdev_dequeue_request(), blk_end_request uses list_empty(&rq->queuelist) (blk_queued_rq() macro is added for it). So drivers must re-initialize it using list_init() or so before calling blk_end_request if drivers use it for its specific purpose. (Currently, there is no driver which completes request without re-initializing the queuelist after used it. So rq->queuelist can be used for the purpose above.) "Normal" drivers can be converted to use blk_end_request() in a standard way shown below. a) end_that_request_{chunk/first} spin_lock_irqsave() (add_disk_randomness(), blk_queue_end_tag(), blkdev_dequeue_request()) end_that_request_last() spin_unlock_irqrestore() => blk_end_request() b) spin_lock_irqsave() end_that_request_{chunk/first} (add_disk_randomness(), blk_queue_end_tag(), blkdev_dequeue_request()) end_that_request_last() spin_unlock_irqrestore() => spin_lock_irqsave() __blk_end_request() spin_unlock_irqsave() c) spin_lock_irqsave() (add_disk_randomness(), blk_queue_end_tag(), blkdev_dequeue_request()) end_that_request_last() spin_unlock_irqrestore() => blk_end_request() or spin_lock_irqsave() __blk_end_request() spin_unlock_irqrestore() 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>
2008-01-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (200 commits) [SCSI] usbstorage: use last_sector_bug flag universally [SCSI] libsas: abstract STP task status into a function [SCSI] ultrastor: clean up inline asm warnings [SCSI] aic7xxx: fix firmware build [SCSI] aacraid: fib context lock for management ioctls [SCSI] ch: remove forward declarations [SCSI] ch: fix device minor number management bug [SCSI] ch: handle class_device_create failure properly [SCSI] NCR5380: fix section mismatch [SCSI] sg: fix /proc/scsi/sg/devices when no SCSI devices [SCSI] IB/iSER: add logical unit reset support [SCSI] don't use __GFP_DMA for sense buffers if not required [SCSI] use dynamically allocated sense buffer [SCSI] scsi.h: add macro for enclosure bit of inquiry data [SCSI] sd: add fix for devices with last sector access problems [SCSI] fix pcmcia compile problem [SCSI] aacraid: add Voodoo Lite class of cards. [SCSI] aacraid: add new driver features flags [SCSI] qla2xxx: Update version number to 8.02.00-k7. [SCSI] qla2xxx: Issue correct MBC_INITIALIZE_FIRMWARE command. ...
2008-01-24Kobject: rename kobject_init_ng() to kobject_init()Greg Kroah-Hartman
Now that the old kobject_init() function is gone, rename kobject_init_ng() to kobject_init() to clean up the namespace. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24Kobject: rename kobject_add_ng() to kobject_add()Greg Kroah-Hartman
Now that the old kobject_add() function is gone, rename kobject_add_ng() to kobject_add() to clean up the namespace. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24Kobject: convert block/ll_rw_blk.c to use kobject_init/add_ng()Greg Kroah-Hartman
This converts the code to use the new kobject functions, cleaning up the logic in doing so. Cc: Jens Axboe <axboe@kernel.dk> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24Driver core: convert block from raw kobjects to core devicesKay Sievers
This moves the block devices to /sys/class/block. It will create a flat list of all block devices, with the disks and partitions in one directory. For compatibility /sys/block is created and contains symlinks to the disks. /sys/class/block |-- sda -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda |-- sda1 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda1 |-- sda10 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda10 |-- sda5 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda5 |-- sda6 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda6 |-- sda7 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda7 |-- sda8 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda8 |-- sda9 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda9 `-- sr0 -> ../../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0 /sys/block/ |-- sda -> ../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda `-- sr0 -> ../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0 Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-11[SCSI] block: Introduce new blk_queue_update_dma_alignment interfaceJames Bottomley
The purpose of this is to allow stacked alignment settings, with the ultimate queue alignment being set to the largest alignment requirement in the stack. The reason for this is so that the SCSI mid-layer can relax the default alignment requirements (which are basically causing a lot of superfluous copying to go on in the SG_IO interface) while allowing transports, devices or HBAs to add stricter limits if they need them. Acked-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2007-11-27Revert "ll_rw_blk: temporarily enable max_segments tweaking"Jens Axboe
This was a temporary debugging thing for sg chaining testing, revert it now as it has served its purpose. This reverts commit 563063a808de6b2004d5b8a09ddcb6125481f4b2. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-09Add UNPLUG traces to all appropriate placesAlan D. Brunelle
Added blk_unplug interface, allowing all invocations of unplugs to result in a generated blktrace UNPLUG. Signed-off-by: Alan D. Brunelle <Alan.Brunelle@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-09block: fix requeue handling in blk_queue_invalidate_tags()Jens Axboe
Credit goes to juergen.kadidlo@exasol.com for diagnosing this issue and supplying the initial patch. blk_queue_invalidate_tags() must use the proper requeueing paths instead of open coding the re-add of the request, otherwise we bug out in rq accounting. Just switch to using blk_requeue_request(), that takes care of end-tag handling as well and also adds the blktrace REQUEUE notify event that is also appropriate here. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-03Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: [BLOCK] Don't allow empty barriers to be passed down to queues that don't grok them dm: bounce_pfn limit added Deadline iosched: Fix batching fairness Deadline iosched: Reset batch for ordered requests Deadline iosched: Factor out finding latter reques
2007-11-02[BLOCK] Don't allow empty barriers to be passed down to queues that don't ↵Jens Axboe
grok them Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-02[SG] Get rid of __sg_mark_end()Jens Axboe
sg_mark_end() overwrites the page_link information, but all users want __sg_mark_end() behaviour where we just set the end bit. That is the most natural way to use the sg list, since you'll fill it in and then mark the end point. So change sg_mark_end() to only set the termination bit. Add a sg_magic debug check as well, and clear a chain pointer if it is set. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-29[BLOCK] Fix bad sharing of tag busy list on queues with shared tag mapsJens Axboe
For the locking to work, only the tag map and tag bit map may be shared (incidentally, I was just explaining this to Nick yesterday, but I apparently didn't review the code well enough myself). But we also share the busy list! The busy_list must be queue private, or we need a block_queue_tag covering lock as well. So we have to move the busy_list to the queue. This'll work fine, and it'll actually also fix a problem with blk_queue_invalidate_tags() which will invalidate tags across all shared queues. This is a bit confusing, the low level driver should call it for each queue seperately since otherwise you cannot kill tags on just a single queue for eg a hard drive that stops responding. Since the function has no callers currently, it's not an issue. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-29block: use lock bitops for the tag map.Nick Piggin
The block queue tag map can use lock bitops. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-29blk_sync_queue() should cancel request_queue->unplug_workOleg Nesterov
blk_sync_queue() cancels the timer, but forgets to cancel the work. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-29block layer: remove a unused argument of drive_stat_acct()Jerome Marchand
The nr_sector argument of drive_stat_acct() is not used anymore since the read and write sectors statistics are now updated in end_that_request_first(). This patch removes the useless argument. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-24SG: Change sg_set_page() to take length and offset argumentJens Axboe
Most drivers need to set length and offset as well, so may as well fold those three lines into one. Add sg_assign_page() for those two locations that only needed to set the page, where the offset/length is set outside of the function context. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-23[BLOCK] blk_rq_map_sg: force clear termination bitJens Axboe
Since blk_rq_map_sg() sets the termination bit at the end of the sg table, we could see it prematurely on the next mapping unless we force drivers to do a full sg_init_table() prior to each mapping. So force clear the termination bit to avoid having to put that clear in the driver for every mapping. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-23[BLOCK] Don't clear sg_dma_len/addr() in blk_rq_map_sg()Jens Axboe
It's not a proper lvalue on all archs. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-22[SG] Update block layer to use sg helpersJens Axboe
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-19Use helpers to obtain task pid in printksPavel Emelyanov
The task_struct->pid member is going to be deprecated, so start using the helpers (task_pid_nr/task_pid_vnr/task_pid_nr_ns) in the kernel. The first thing to start with is the pid, printed to dmesg - in this case we may safely use task_pid_nr(). Besides, printks produce more (much more) than a half of all the explicit pid usage. [akpm@linux-foundation.org: git-drm went and changed lots of stuff] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Dave Airlie <airlied@linux.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19kernel-api docbook: fix content problemsRandy Dunlap
Fix kernel-api docbook contents problems. docproc: linux-2.6.23-git13/include/asm-x86/unaligned_32.h: No such file or directory Warning(linux-2.6.23-git13//include/linux/list.h:482): bad line: of list entry Warning(linux-2.6.23-git13//mm/filemap.c:864): No description found for parameter 'ra' Warning(linux-2.6.23-git13//block/ll_rw_blk.c:3760): No description found for parameter 'req' Warning(linux-2.6.23-git13//include/linux/input.h:1077): No description found for parameter 'private' Warning(linux-2.6.23-git13//include/linux/input.h:1077): No description found for parameter 'cdev' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: WU Fengguang <wfg@mail.ustc.edu.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17[BLOCK] blk_rq_map_sg() next_sg fixupJens Axboe
Don't ever use sg_next() on the last entry, it may not be valid! Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-17Merge branch 'for-linus' of git://git.kernel.dk/data/git/linux-2.6-blockLinus Torvalds
* 'for-linus' of git://git.kernel.dk/data/git/linux-2.6-block: [SCSI] Remove full sg table memset() [SCSI] ide-scsi: remove usage of sg_last() Fix loop terminating conditions in fill_sg(). [BLOCK] Clear sg entry before filling in blk_rq_map_sg() IA64: iommu uses sg_next with an invalid sg element cciss: disable DMA refetch on Smart Array P600 swiotlb: fix map_sg failure handling SPARC64: fix iommu sg chaining [SCSI] ide-scsi: use scsi_sg_count() instead of ->use_sg
2007-10-17mm: bdi init hooksPeter Zijlstra
provide BDI constructor/destructor hooks [akpm@linux-foundation.org: compile fix] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17[BLOCK] Clear sg entry before filling in blk_rq_map_sg()Jens Axboe
The memset() of the sg entry was originally removed, because it could overwrite a chain pointer. But it's quite OK to memset() it when we know it's a valid entry, since it can't contain a chain pointer. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-16Merge branch 'for-linus' of git://git.kernel.dk/data/git/linux-2.6-blockLinus Torvalds
* 'for-linus' of git://git.kernel.dk/data/git/linux-2.6-block: (63 commits) Fix memory leak in dm-crypt SPARC64: sg chaining support SPARC: sg chaining support PPC: sg chaining support PS3: sg chaining support IA64: sg chaining support x86-64: enable sg chaining x86-64: update pci-gart iommu to sg helpers x86-64: update nommu to sg helpers x86-64: update calgary iommu to sg helpers swiotlb: sg chaining support i386: enable sg chaining i386 dma_map_sg: convert to using sg helpers mmc: need to zero sglist on init Panic in blk_rq_map_sg() from CCISS driver remove sglist_len remove blk_queue_max_phys_segments in libata revert sg segment size ifdefs Fixup u14-34f ENABLE_SG_CHAINING qla1280: enable use_sg_chaining option ...
2007-10-16readahead: remove the limit max_sectors_kb imposed on max_readahead_kbFengguang Wu
Remove the size limit max_sectors_kb imposed on max_readahead_kb. The size restriction is unreasonable. Especially when max_sectors_kb cannot grow larger than max_hw_sectors_kb, which can be rather small for some disk drives. Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn> Acked-by: Jens Axboe <jens.axboe@oracle.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16ll_rw_blk: temporarily enable max_segments tweakingJens Axboe
Expose this setting for now, so that users can play with enabling large commands without defaulting it to on globally. This is a debug patch, it will be dropped for the final versions. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-16block: convert to using sg helpersJens Axboe
Convert the main rq mapper (blk_rq_map_sg()) to the sg helper setup. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-16block: convert blkdev_issue_flush() to use empty barriersJens Axboe
Then we can get rid of ->issue_flush_fn() and all the driver private implementations of that. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-16block: Initial support for data-less (or empty) barrier supportJens Axboe
This implements functionality to pass down or insert a barrier in a queue, without having data attached to it. The ->prepare_flush_fn() infrastructure from data barriers are reused to provide this functionality. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-16block: factor our bio_check_eod()Jens Axboe
End of device check is done twice in __generic_make_request() and it's fully inlined each time. Factor out bio_check_eod(). Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-16block: add end_queued_request() and end_dequeued_request() helpersJens Axboe
We can use this helper in the elevator core for BLKPREP_KILL, and it'll also be useful for the empty barrier patch. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-16block: ll_rw_blk.c: cosmeticsJens Axboe
Fix ?: construct, a typo, whitespace, and similar. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-12kobjects: fix up improper use of the kobject name fieldGreg Kroah-Hartman
A number of different drivers incorrect access the kobject name field directly. This is not correct as the name might not be in the array. Use the proper accessor function instead.
2007-10-10Drop 'size' argument from bio_endio and bi_end_ioNeilBrown
As bi_end_io is only called once when the reqeust is complete, the 'size' argument is now redundant. Remove it. Now there is no need for bio_endio to subtract the size completed from bi_size. So don't do that either. While we are at it, change bi_end_io to return void. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-10Don't decrement bi_size in bio_endioNeilBrown
The only caller of bio_endio that does not pass the full bi_size is end_that_request_first. Also, no ->bi_end_io method is really interested in bi_size being decremented. So move the decrement and related code into ll_rw_blk and merge it with order_bio_endio to form req_bio_endio which does endio functionality specific to request completion. As some ->bi_end_io methods do check bi_size of 0, we set it thus for now, but that will go in the next patch. Signed-off-by: Neil Brown <neilb@suse.de> ### Diffstat output ./block/ll_rw_blk.c | 42 +++++++++++++++++++++++++++--------------- ./fs/bio.c | 23 +++++++++++------------ 2 files changed, 38 insertions(+), 27 deletions(-) diff .prev/block/ll_rw_blk.c ./block/ll_rw_blk.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-10Remove flush_dry_bio_endioNeilBrown
The entire function of flush_dry_bio_endio is to undo the effects of bio_endio (when called on a barrier request). So remove the function and the call to bio_endio. This allows us to remove "bi_size" from "struct request_queue". Signed-off-by: Neil Brown <neilb@suse.de> ### Diffstat output ./block/ll_rw_blk.c | 39 ++------------------------------------- ./include/linux/blkdev.h | 1 - 2 files changed, 2 insertions(+), 38 deletions(-) diff .prev/block/ll_rw_blk.c ./block/ll_rw_blk.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-10ll_rw_blk: blk_cpu_notifier should be __cpuinitdataSatyam Sharma
blk_cpu_notifier is marked as __devinitdata, but __devinitdata need not be __init even if HOTPLUG_CPU=n, which wastes space. It should be marked __cpuinitdata, and the callback itself as __cpuinit. Signed-off-by: Satyam Sharma <satyam@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-10Fixup rq_for_each_segment() indentationJens Axboe
Remove one level of nesting where appropriate. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-10Share code between init_request_from_bio and blk_rq_bio_prepNeilBrown
These have very similar functions and should share code where possible. Signed-off-by: Neil Brown <neilb@suse.de> diff .prev/block/ll_rw_blk.c ./block/ll_rw_blk.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-10Stop exporting blk_rq_bio_prepNeilBrown
blk_rq_bio_prep is exported for use in exactly one place. That place can benefit from using the new blk_rq_append_bio instead. So - change dm-emc to call blk_rq_append_bio - stop exporting blk_rq_bio_prep, and - initialise rq_disk in blk_rq_bio_prep, as dm-emc needs it. Signed-off-by: Neil Brown <neilb@suse.de> diff .prev/block/ll_rw_blk.c ./block/ll_rw_blk.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-10New function blk_req_append_bioNeilBrown
ll_back_merge_fn is currently exported to SCSI where is it used, together with blk_rq_bio_prep, in exactly the same way these functions are used in __blk_rq_map_user. So move the common code into a new function (blk_rq_append_bio), and don't export ll_back_merge_fn any longer. Signed-off-by: Neil Brown <neilb@suse.de> diff .prev/block/ll_rw_blk.c ./block/ll_rw_blk.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-10Introduce rq_for_each_segment replacing rq_for_each_bioNeilBrown
Every usage of rq_for_each_bio wraps a usage of bio_for_each_segment, so these can be combined into rq_for_each_segment. We define "struct req_iterator" to hold the 'bio' and 'index' that are needed for the double iteration. Signed-off-by: Neil Brown <neilb@suse.de> Various compile fixes by me... Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-10Merge blk_recount_segments into blk_recalc_rq_segmentsNeilBrown
blk_recalc_rq_segments calls blk_recount_segments on each bio, then does some extra calculations to handle segments that overlap two bios. If we merge the code from blk_recount_segments into blk_recalc_rq_segments, we can process the whole request one bio_vec at a time, and not need the messy cross-bio calculations. Then blk_recount_segments can be implemented by calling blk_recalc_rq_segments, passing it a simple on-stack request which stores just the bio. Signed-off-by: Neil Brown <neilb@suse.de> diff .prev/block/ll_rw_blk.c ./block/ll_rw_blk.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-09-14shared tag queue barrier commentNick Piggin
Should add some comments for the tag barriers (they won't be so important if we can switch over to the explicit _lock bitops, but for now we should make it clear). Jens' original patch said a barrier after the test_and_clear_bit was also required. I can't see why (and it would prevent the use of the _lock bitop). Acked-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --