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* sysfs: add /sys/dev/{char,block} to lookup sysfs path by major:minorDan Williams2008-07-211-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Why?: There are occasions where userspace would like to access sysfs attributes for a device but it may not know how sysfs has named the device or the path. For example what is the sysfs path for /dev/disk/by-id/ata-ST3160827AS_5MT004CK? With this change a call to stat(2) returns the major:minor then userspace can see that /sys/dev/block/8:32 links to /sys/block/sdc. What are the alternatives?: 1/ Add an ioctl to return the path: Doable, but sysfs is meant to reduce the need to proliferate ioctl interfaces into the kernel, so this seems counter productive. 2/ Use udev to create these symlinks: Also doable, but it adds a udev dependency to utilities that might be running in a limited environment like an initramfs. 3/ Do a full-tree search of sysfs. [kay.sievers@vrfy.org: fix duplicate registrations] [kay.sievers@vrfy.org: cleanup suggestions] Cc: Neil Brown <neilb@suse.de> Cc: Tejun Heo <htejun@gmail.com> Acked-by: Kay Sievers <kay.sievers@vrfy.org> Reviewed-by: SL Baur <steve@xemacs.org> Acked-by: Kay Sievers <kay.sievers@vrfy.org> Acked-by: Mark Lord <lkml@rtr.ca> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6Linus Torvalds2008-07-151-3/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (102 commits) [SCSI] scsi_dh: fix kconfig related build errors [SCSI] sym53c8xx: Fix bogus sym_que_entry re-implementation of container_of [SCSI] scsi_cmnd.h: remove double inclusion of linux/blkdev.h [SCSI] make struct scsi_{host,target}_type static [SCSI] fix locking in host use of blk_plug_device() [SCSI] zfcp: Cleanup external header file [SCSI] zfcp: Cleanup code in zfcp_erp.c [SCSI] zfcp: zfcp_fsf cleanup. [SCSI] zfcp: consolidate sysfs things into one file. [SCSI] zfcp: Cleanup of code in zfcp_aux.c [SCSI] zfcp: Cleanup of code in zfcp_scsi.c [SCSI] zfcp: Move status accessors from zfcp to SCSI include file. [SCSI] zfcp: Small QDIO cleanups [SCSI] zfcp: Adapter reopen for large number of unsolicited status [SCSI] zfcp: Fix error checking for ELS ADISC requests [SCSI] zfcp: wait until adapter is finished with ERP during auto-port [SCSI] ibmvfc: IBM Power Virtual Fibre Channel Adapter Client Driver [SCSI] sg: Add target reset support [SCSI] lib: Add support for the T10 (SCSI) Data Integrity Field CRC [SCSI] sd: Move scsi_disk() accessor function to sd.h ...
| * [SCSI] bsg: fix bsg_mutex hang with device removalFUJITA Tomonori2008-07-121-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We don't need to hold bsg_mutex during bsg_complete_all_commands(). It leads to a problem that we block bsg_unregister_queue during bsg_complete_all_commands (untill all the outstanding commands complete). Thanks to Pete Wyckoff for finding the bug and testing the patch. The detailed bug report is: http://marc.info/?l=linux-scsi&m=121182137132145&w=2 Tested-by: Pete Wyckoff <pw@osc.edu> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6Linus Torvalds2008-07-152-11/+7
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: (80 commits) ide-floppy: fix unfortunate function naming ide-tape: unify idetape_create_read/write_cmd ide: add ide_pc_intr() helper ide-{floppy,scsi}: read Status Register before stopping DMA engine ide-scsi: add more debugging to idescsi_pc_intr() ide-scsi: use pc->callback ide-floppy: add more debugging to idefloppy_pc_intr() ide-tape: always log debug info in idetape_pc_intr() if debugging is enabled ide-tape: add ide_tape_io_buffers() helper ide-tape: factor out DSC handling from idetape_pc_intr() ide-{floppy,tape}: move checking of ->failed_pc to ->callback ide: add ide_issue_pc() helper ide: add PC_FLAG_DRQ_INTERRUPT pc flag ide-scsi: move idescsi_map_sg() call out from idescsi_issue_pc() ide: add ide_transfer_pc() helper ide-scsi: set drive->scsi flag for devices handled by the driver ide-{cd,floppy,tape}: remove checking for drive->scsi ide: add PC_FLAG_ZIP_DRIVE pc flag ide-tape: factor out waiting for good ireason from idetape_transfer_pc() ide-tape: set PC_FLAG_DMA_IN_PROGRESS flag in idetape_transfer_pc() ...
| * | block: unexport blk_end_sync_rqFUJITA Tomonori2008-07-151-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All the users of blk_end_sync_rq has gone (they are converted to use blk_execute_rq). This unexports blk_end_sync_rq. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Borislav Petkov <petkovbb@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
| * | block: remove the checking for NULL queue in blk_put_requestFUJITA Tomonori2008-07-151-9/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some uses blk_put_request asymmetrically, that is, they uses it with requests that not allocated by blk_get_request. As a result, blk_put_request has a hack to catch a NULL request_queue. Now such callers are fixed (they use blk_get_request properly). So we can safely remove the hack in blk_put_request. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Borislav Petkov <petkovbb@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
| * | block: handle blk_pm_resume_request() requests in blk_execute_rq_nowait()Bartlomiej Zolnierkiewicz2008-07-151-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For blk_pm_resume_request() requests (which are used only by IDE subsystem currently) the queue is stopped so we need to call ->request_fn explicitly. Thanks to: - Rafael for reporting/bisecting the bug - Borislav/Rafael for testing the fix This is a preparation for converting IDE to use blk_execute_rq(). Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Borislav Petkov <petkovbb@gmail.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* | | Merge branch 'core/softirq' of ↵Linus Torvalds2008-07-141-1/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core/softirq' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: softirq: remove irqs_disabled warning from local_bh_enable softirq: remove initialization of static per-cpu variable Remove argument from open_softirq which is always NULL
| * \ \ Merge branch 'linus' into core/softirqIngo Molnar2008-06-165-30/+76
| |\ \ \
| * | | | Remove argument from open_softirq which is always NULLCarlos R. Mafra2008-05-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As git-grep shows, open_softirq() is always called with the last argument being NULL block/blk-core.c: open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL); kernel/hrtimer.c: open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL); kernel/rcuclassic.c: open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL); kernel/rcupreempt.c: open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL); kernel/sched.c: open_softirq(SCHED_SOFTIRQ, run_rebalance_domains, NULL); kernel/softirq.c: open_softirq(TASKLET_SOFTIRQ, tasklet_action, NULL); kernel/softirq.c: open_softirq(HI_SOFTIRQ, tasklet_hi_action, NULL); kernel/timer.c: open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL); net/core/dev.c: open_softirq(NET_TX_SOFTIRQ, net_tx_action, NULL); net/core/dev.c: open_softirq(NET_RX_SOFTIRQ, net_rx_action, NULL); This observation has already been made by Matthew Wilcox in June 2002 (http://www.cs.helsinki.fi/linux/linux-kernel/2002-25/0687.html) "I notice that none of the current softirq routines use the data element passed to them." and the situation hasn't changed since them. So it appears we can safely remove that extra argument to save 128 (54) bytes of kernel data (text). Signed-off-by: Carlos R. Mafra <crmafra@ift.unesp.br> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | | Merge branch 'bkl-removal' of git://git.lwn.net/linux-2.6Linus Torvalds2008-07-141-1/+6
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'bkl-removal' of git://git.lwn.net/linux-2.6: (146 commits) IB/umad: BKL is not needed for ib_umad_open() IB/uverbs: BKL is not needed for ib_uverbs_open() bf561-coreb: BKL unneeded for open() Call fasync() functions without the BKL snd/PCM: fasync BKL pushdown ipmi: fasync BKL pushdown ecryptfs: fasync BKL pushdown Bluetooth VHCI: fasync BKL pushdown tty_io: fasync BKL pushdown tun: fasync BKL pushdown i2o: fasync BKL pushdown mpt: fasync BKL pushdown Remove BKL from remote_llseek v2 Make FAT users happier by not deadlocking x86-mce: BKL pushdown vmwatchdog: BKL pushdown vmcp: BKL pushdown via-pmu: BKL pushdown uml-random: BKL pushdown uml-mmapper: BKL pushdown ...
| * \ \ \ \ Merge commit 'v2.6.26' into bkl-removalJonathan Corbet2008-07-147-31/+80
| |\ \ \ \ \ | | | |_|/ / | | |/| | |
| * | | | | bsg: cdev lock_kernel() pushdownJonathan Corbet2008-05-181-1/+6
| | |/ / / | |/| | | | | | | | | | | | | | | | | | | | | | | Push the cdev lock_kernel call into bsg_open(). Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | | | | Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2008-07-1416-157/+959
|\ \ \ \ \ | |_|/ / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.kernel.dk/linux-2.6-block: (37 commits) splice: fix generic_file_splice_read() race with page invalidation ramfs: enable splice write drivers/block/pktcdvd.c: avoid useless memset cdrom: revert commit 22a9189 (cdrom: use kmalloced buffers instead of buffers on stack) scsi: sr avoids useless buffer allocation block: blk_rq_map_kern uses the bounce buffers for stack buffers block: add blk_queue_update_dma_pad DAC960: push down BKL pktcdvd: push BKL down into driver paride: push ioctl down into driver block: use get_unaligned_* helpers block: extend queue_flag bitops block: request_module(): use format string Add bvec_merge_data to handle stacked devices and ->merge_bvec() block: integrity flags can't use bit ops on unsigned short cmdfilter: extend default read filter sg: fix odd style (extra parenthesis) introduced by cmd filter patch block: add bounce support to blk_rq_map_user_iov cfq-iosched: get rid of enable_idle being unused warning allow userspace to modify scsi command filter on per device basis ...
| * | | | block: blk_rq_map_kern uses the bounce buffers for stack buffersFUJITA Tomonori2008-07-041-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blk_rq_map_kern is used for kernel internal I/Os. Some callers use this function with stack buffers but DMA to/from the stack buffers leads to memory corruption on a non-coherent platform. This patch make blk_rq_map_kern uses the bounce buffers if a caller passes a stack buffer (on the all platforms for simplicity). Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Tejun Heo <htejun@gmail.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | block: add blk_queue_update_dma_padFUJITA Tomonori2008-07-041-4/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds blk_queue_update_dma_pad to prevent LLDs from overwriting the dma pad mask wrongly (we added blk_queue_update_dma_alignment due to the same reason). This also converts libata to use blk_queue_update_dma_pad instead of blk_queue_dma_pad. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Tejun Heo <htejun@gmail.com> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | block: extend queue_flag bitopsJens Axboe2008-07-031-8/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add test_and_clear and test_and_set. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | block: request_module(): use format stringmaximilian attems2008-07-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Avoid bad things happening if the module has a printk control string in its name. Signed-off-by: maximilian attems <max@stro.at> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | block: integrity flags can't use bit ops on unsigned shortJens Axboe2008-07-031-10/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just use normal open coded bit operations instead, they need not be atomic. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | cmdfilter: extend default read filterAdel Gadllah2008-07-031-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the commands that the former sg filter allowed for read access to the cmdfilter to keep userspace apps that rely on them working. Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | block: add bounce support to blk_rq_map_user_iovFUJITA Tomonori2008-07-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blk_rq_map_user_iov can't handle the bounce buffer (it means that the bio_map_user_iov path doesn't work with a LLD that needs GFP_DMA). This patch fixes blk_rq_map_user_iov to support the bounce buffer. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | cfq-iosched: get rid of enable_idle being unused warningJens Axboe2008-07-031-1/+1
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | allow userspace to modify scsi command filter on per device basisAdel Gadllah2008-07-035-128/+361
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch exports the per-gendisk command filter to user space through sysfs, so it can be changed by the system administrator. All users of the old cmd filter have been converted to use the new one. Original patch from Peter Jones. Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com> Signed-off-by: Peter Jones <pjones@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | block: integrity checkpatch cleanupsJens Axboe2008-07-031-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | > 80 char lines and that sort of thing. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | block: Block layer data integrity supportMartin K. Petersen2008-07-037-0/+419
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some block devices support verifying the integrity of requests by way of checksums or other protection information that is submitted along with the I/O. This patch implements support for generating and verifying integrity metadata, as well as correctly merging, splitting and cloning bios and requests that have this extra information attached. See Documentation/block/data-integrity.txt for more information. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | block: export "ro" attributeKay Sievers2008-07-031-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | Added in user-injected messages into blk tracesAlan D. Brunelle2008-07-031-0/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows a user to annotate the blk trace stream: writing a suitable message to {/sys/kernel/debug}/block/<dsf>/msg will have it propagated into the trace stream. Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | cfq-iosched: add message logging through blktraceJens Axboe2008-07-031-10/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that blktrace has the ability to carry arbitrary messages in its stream, use that for some CFQ logging. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | as-iosched: properly protect ioc_gone and ioc countJens Axboe2008-07-031-3/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we have multiple tasks freeing io contexts when as-iosched is being unloaded, we could complete() ioc_gone twice. Fix that by protecting ioc_gone complete() and clearing with a spinlock for just that purpose. Doesn't matter from a performance perspective, since it'll only enter that path when ioc_gone != NULL (when as-iosched is being rmmod'ed). Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | cfq-iosched: properly protect ioc_gone and ioc countJens Axboe2008-07-031-3/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we have multiple tasks freeing cfq_io_contexts when cfq-iosched is being unloaded, we could complete() ioc_gone twice. Fix that by protecting ioc_gone complete() and clearing with a spinlock for just that purpose. Doesn't matter from a performance perspective, since it'll only enter that path when ioc_gone != NULL (when cfq-iosched is being rmmod'ed). Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | | | [SCSI] bsg: fix oops on removeJames Bottomley2008-07-121-1/+2
|/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If you do a modremove of any sas driver, you run into an oops on shutdown when the host is removed (coming from the host bsg device). The root cause seems to be that there's a use after free of the bsg_class_device: In bsg_kref_release_function, this is used (to do a put_device(bcg->parent) after bcg->release has been called. In sas (and possibly many other things) bcd->release frees the queue which contains the bsg_class_device, so we get a put_device on unreferenced memory. Fix this by taking a copy of the pointer to the parent before releasing bsg. Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
* | | | block: Fix the starving writes bug in the anticipatory IO schedulerDivyesh Shah2008-07-011-0/+2
| |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | AS scheduler alternates between issuing read and write batches. It does the batch switch only after all requests from the previous batch are completed. When switching to a write batch, if there is an on-going read request, it waits for its completion and indicates its intention of switching by setting ad->changed_batch and the new direction but does not update the batch_expire_time for the new write batch which it does in the case of no previous pending requests. On completion of the read request, it sees that we were waiting for the switch and schedules work for kblockd right away and resets the ad->changed_data flag. Now when kblockd enters dispatch_request where it is expected to pick up a write request, it in turn ends the write batch because the batch_expire_timer was not updated and shows the expire timestamp for the previous batch. This results in the write starvation for all the cases where there is the intention for switching to a write batch, but there is a previous in-flight read request and the batch gets reverted to a read_batch right away. This also holds true in the reverse case (switching from a write batch to a read batch with an in-flight write request). I've checked that this bug exists on 2.6.11, 2.6.18, 2.6.24 and linux-2.6-block git HEAD. I've tested the fix on x86 platforms with SCSI drives where the driver asks for the next request while a current request is in-flight. This patch is based off linux-2.6-block git HEAD. Bug reproduction: A simple scenario which reproduces this bug is: - dd if=/dev/hda3 of=/dev/null & - lilo The lilo takes forever to complete. This can also be reproduced fairly easily with the earlier dd and another test program doing msync(). The example test program below should print out a message after every iteration but it simply hangs forever. With this bugfix it makes forward progress. ==== Example test program using msync() (thanks to suleiman AT google DOT com) inline uint64_t rdtsc(void) { int64_t tsc; __asm __volatile("rdtsc" : "=A" (tsc)); return (tsc); } int main(int argc, char **argv) { struct stat st; uint64_t e, s, t; char *p, q; long i; int fd; if (argc < 2) { printf("Usage: %s <file>\n", argv[0]); return (1); } if ((fd = open(argv[1], O_RDWR | O_NOATIME)) < 0) err(1, "open"); if (fstat(fd, &st) < 0) err(1, "fstat"); p = mmap(NULL, st.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); t = 0; for (i = 0; i < 1000; i++) { *p = 0; msync(p, 4096, MS_SYNC); s = rdtsc(); *p = 0; __asm __volatile(""::: "memory"); e = rdtsc(); if (argc > 2) printf("%d: %lld cycles %jd %jd\n", i, e - s, (intmax_t)s, (intmax_t)e); t += e - s; } printf("average time: %lld cycles\n", t / 1000); return (0); } Cc: <stable@kernel.org> Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | block: disable IRQs until data is written to relay channelCarl Henrik Lunde2008-06-121-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As we may run relay_reserve from interrupt context we must always disable IRQs. This is because a call to relay_reserve may expose previously written data to use space. Updated new message code and an old but related comment. Signed-off-by: Carl Henrik Lunde <chlunde@ping.uio.no> Signed-off-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Fix invalid access errors in blk_lookup_devtLinus Torvalds2008-06-091-0/+2
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 30f2f0eb4bd2c43d10a8b0d872c6e5ad8f31c9a0 ("block: do_mounts - accept root=<non-existant partition>") extended blk_lookup_devt() to be able to look up partitions that had not yet been registered, but in the process made the assumption that the '&block_class.devices' list only contains disk devices and that you can do 'dev_to_disk(dev)' on them. That isn't actually true. The block_class device list also contains the partitions we've discovered so far, and you can't just do a 'dev_to_disk()' on those. So make sure to only work on devices that block/genhd.c has registered itself, something we can test by checking the 'dev->type' member. This makes the loop in blk_lookup_devt() match the other such loops in this file. [ We may want to do an alternate version that knows to handle _either_ whole-disk devices or partitions, but for now this is the minimal fix for a series of crashes reported by Mariusz Kozlowski in http://lkml.org/lkml/2008/5/25/25 and Ingo in http://lkml.org/lkml/2008/6/9/39 ] Reported-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl> Reported-by: Ingo Molnar <mingo@elte.hu> Cc: Neil Brown <neilb@suse.de> Cc: Joao Luis Meloni Assirati <assirati@nonada.if.usp.br> Acked-by: Kay Sievers <kay.sievers@vrfy.org> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | cfq-iosched: fix RCU problem in cfq_cic_lookup()Jens Axboe2008-05-281-2/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | cfq_cic_lookup() needs to properly protect ioc->ioc_data before dereferencing it and also exclude updaters of ioc->ioc_data as well. Also add a number of comments documenting why the existing RCU usage is OK. Thanks a lot to "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> for review and comments! Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | block: make blktrace use per-cpu buffers for message notesJens Axboe2008-05-281-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | Currently it uses a single static char array, but that risks being corrupted when multiple users issue message notes at the same time. Make the buffers dynamically allocated when the trace is setup and make them per-cpu instead. The default max message size of 1k is also very large, the interface is mainly for small text notes. So shrink it to 128 bytes. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | Added in elevator switch message to blktrace streamAlan D. Brunelle2008-05-281-0/+2
| | | | | | | | | | Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | Added in MESSAGE notes for blktracesAlan D. Brunelle2008-05-281-0/+14
| | | | | | | | | | | | | | Allows messages to be inserted into blktrace streams. Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | block: reorder cfq_queue to save space on 64bit buildsRichard Kennedy2008-05-281-4/+4
| | | | | | | | | | | | | | | | saves 8 bytes of padding & increases objects/slab from 30 to 32 on my AMD64 config Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | block: Move the second call to get_request to the end of the loopZhang, Yanmin2008-05-281-20/+17
|/ | | | | | | | | In function get_request_wait, the second call to get_request could be moved to the end of the while loop, because if the first call to get_request fails, the second call will fail without sleep. Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Remove blkdev warning triggered by using mdNeil Brown2008-05-142-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | As setting and clearing queue flags now requires that we hold a spinlock on the queue, and as blk_queue_stack_limits is called without that lock, get the lock inside blk_queue_stack_limits. For blk_queue_stack_limits to be able to find the right lock, each md personality needs to set q->queue_lock to point to the appropriate lock. Those personalities which didn't previously use a spin_lock, us q->__queue_lock. So always initialise that lock when allocated. With this in place, setting/clearing of the QUEUE_FLAG_PLUGGED bit will no longer cause warnings as it will be clear that the proper lock is held. Thanks to Dan Williams for review and fixing the silly bugs. Signed-off-by: NeilBrown <neilb@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Alistair John Strachan <alistair@devzero.co.uk> Cc: Nick Piggin <npiggin@suse.de> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Jacek Luczak <difrost.kernel@gmail.com> Cc: Prakash Punnoor <prakash@punnoor.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block: do_mounts - accept root=<non-existant partition>Kay Sievers2008-05-141-3/+6
| | | | | | | | | | | | | | | | Some devices, like md, may create partitions only at first access, so allow root= to be set to a valid non-existant partition of an existing disk. This applies only to non-initramfs root mounting. This fixes a regression from 2.6.24 which did allow this to happen and broke some users machines :( Acked-by: Neil Brown <neilb@suse.de> Tested-by: Joao Luis Meloni Assirati <assirati@nonada.if.usp.br> Cc: stable <stable@kernel.org> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Fix misuses of bdevname()Jean Delvare2008-05-132-2/+2
| | | | | | | | | | | | | bdevname() fills the buffer that it is given as a parameter, so calling strcpy() or snprintf() on the returned value is redundant (and probably not guaranteed to work - I don't think strcpy and snprintf support overlapping buffers.) Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Stephen Tweedie <sct@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block: avoid duplicate calls to get_part() in disk stat codeJens Axboe2008-05-071-8/+10
| | | | | | | | | get_part() is fairly expensive, as it O(N) loops over partitions to find the right one. In lots of normal IO paths we end up looking up the partition twice, to make matters even worse. Change the stat add code to accept a passed in partition instead. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* cfq-iosched: make io priorities inherit CPU scheduling class as well as niceJens Axboe2008-05-071-2/+2
| | | | | | | | We currently set all processes to the best-effort scheduling class, regardless of what CPU scheduling class they belong to. Improve that so that we correctly track idle and rt scheduling classes as well. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: optimize generic_unplug_device()Jens Axboe2008-05-071-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | Original patch from Mikulas Patocka <mpatocka@redhat.com> Mike Anderson was doing an OLTP benchmark on a computer with 48 physical disks mapped to one logical device via device mapper. He found that there was a slowdown on request_queue->lock in function generic_unplug_device. The slowdown is caused by the fact that when some code calls unplug on the device mapper, device mapper calls unplug on all physical disks. These unplug calls take the lock, find that the queue is already unplugged, release the lock and exit. With the below patch, performance of the benchmark was increased by 18% (the whole OLTP application, not just block layer microbenchmarks). So I'm submitting this patch for upstream. I think the patch is correct, because when more threads call simultaneously plug and unplug, it is unspecified, if the queue is or isn't plugged (so the patch can't make this worse). And the caller that plugged the queue should unplug it anyway. (if it doesn't, there's 3ms timeout). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: get rid of likely/unlikely predictions in merge logicJens Axboe2008-05-071-6/+6
| | | | | | | They tend to depend a lot on the workload, so not a clear-cut likely or unlikely fit. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* cfq-iosched: fix RCU race in the cfq io_context destructor handlingJens Axboe2008-05-072-7/+14
| | | | | | | | | | | | | | put_io_context() drops the RCU read lock before calling into cfq_dtor(), however we need to hold off freeing there before grabbing and dereferencing the first object on the list. So extend the rcu_read_lock() scope to cover the calling of cfq_dtor(), and optimize cfq_free_io_context() to use a new variant for call_for_each_cic() that assumes the RCU read lock is already held. Hit in the wild by Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: adjust tagging function queue bit lockingJens Axboe2008-05-071-3/+6
| | | | | | | | | | | | For most initialization purposes, calling blk_queue_init_tags() without the queue lock held is OK. Only if called for resizing an existing map must the lock be held. Ditto for tag cleanup, the maps are reference counted. So switch the general queue flag setting to the unlocked variant, but retain the locked variant for resizing. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: sysfs store function needs to grab queue_lock and use queue_flag_*()Jens Axboe2008-05-071-2/+4
| | | | | | | Concurrency isn't a big deal here since we have requests in flight at this point, but do the locked variant to set a better example. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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