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* Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2010-04-09
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.kernel.dk/linux-2.6-block: (34 commits) cfq-iosched: Fix the incorrect timeslice accounting with forced_dispatch loop: Update mtime when writing using aops block: expose the statistics in blkio.time and blkio.sectors for the root cgroup backing-dev: Handle class_create() failure Block: Fix block/elevator.c elevator_get() off-by-one error drbd: lc_element_by_index() never returns NULL cciss: unlock on error path cfq-iosched: Do not merge queues of BE and IDLE classes cfq-iosched: Add additional blktrace log messages in CFQ for easier debugging i2o: Remove the dangerous kobj_to_i2o_device macro block: remove 16 bytes of padding from struct request on 64bits cfq-iosched: fix a kbuild regression block: make CONFIG_BLK_CGROUP visible Remove GENHD_FL_DRIVERFS block: Export max number of segments and max segment size in sysfs block: Finalize conversion of block limits functions block: Fix overrun in lcm() and move it to lib vfs: improve writeback_inodes_wb() paride: fix off-by-one test drbd: fix al-to-on-disk-bitmap for 4k logical_block_size ...
| * block: Fix overrun in lcm() and move it to libMartin K. Petersen2010-03-15
| | | | | | | | | | | | | | | | | | | | | | | | | | lcm() was defined to take integer-sized arguments. The supplied arguments are multiplied, however, causing us to overflow given sufficiently large input. That in turn led to incorrect optimal I/O size reporting in some cases (RAID over RAID). Switch lcm() over to unsigned long similar to gcd() and move the function from blk-settings.c to lib. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-30
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* block: Consolidate phys_segment and hw_segment limitsMartin K. Petersen2010-02-26
| | | | | | | | | Except for SCSI no device drivers distinguish between physical and hardware segment limits. Consolidate the two into a single segment limit. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Rename blk_queue_max_sectors to blk_queue_max_hw_sectorsMartin K. Petersen2010-02-26
| | | | | | | | | | | | | The block layer calling convention is blk_queue_<limit name>. blk_queue_max_sectors predates this practice, leading to some confusion. Rename the function to appropriately reflect that its intended use is to set max_hw_sectors. Also introduce a temporary wrapper for backwards compability. This can be removed after the merge window is closed. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Add BLK_ prefix to definitionsMartin K. Petersen2010-02-26
| | | | | | | Add a BLK_ prefix to block layer constants. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Remove unused accessor functionMartin K. Petersen2010-02-26
| | | | | | | | blk_queue_max_hw_sectors is no longer called by any subsystem and can be removed. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Update blk_queue_max_sectors and documentationMartin K. Petersen2010-02-26
| | | | | | | Clarify blk_queue_max_sectors and update documentation. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Stop using byte offsetsMartin K. Petersen2010-01-11
| | | | | | | | | All callers of the stacking functions use 512-byte sector units rather than byte offsets. Simplify the code so the stacking functions take sectors when specifying data offsets. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: bdev_stack_limits wrapperMartin K. Petersen2010-01-11
| | | | | | | | | | DM does not want to know about partition offsets. Add a partition-aware wrapper that DM can use when stacking block devices. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Correct handling of bottom device misaligmentMartin K. Petersen2010-01-11
| | | | | | | | | | | | The top device misalignment flag would not be set if the added bottom device was already misaligned as opposed to causing a stacking failure. Also massage the reporting so that an error is only returned if adding the bottom device caused the misalignment. I.e. don't return an error if the top is already flagged as misaligned. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Fix incorrect alignment offset reporting and update documentationMartin K. Petersen2009-12-29
| | | | | | | | | | | | | | | queue_sector_alignment_offset returned the wrong value which caused partitions to report an incorrect alignment_offset. Since offset alignment calculation is needed several places it has been split into a separate helper function. The topology stacking function has been updated accordingly. Furthermore, comments have been added to clarify how the stacking function works. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Tested-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Fix topology stacking for data and discard alignmentMartin K. Petersen2009-12-21
| | | | | | | | | | The stacking code incorrectly scaled up the data offset in some cases causing misaligned devices to report alignment. Rewrite the stacking algorithm to remedy this and apply the same alignment principles to the discard handling. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: temporarily disable discard granularityJens Axboe2009-12-16
| | | | | | | | | | | | | Commit 86b37281411cf1e9bc0a6b5406c45edb7bd9ea5d adds a check for misaligned stacking offsets, but it's buggy since the defaults are 0. Hence all dm devices that pass in a non-zero starting offset will be marked as misaligned amd dm will complain. A real fix is coming, in the mean time disable the discard granularity check so that users don't worry about dm reporting about misaligned devices. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 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: jiffies fixesRandy Dunlap2009-11-11
| | | | | | | | | Use HZ-independent calculation of milliseconds. Add jiffies.h where it was missing since functions or macros from it are used. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.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>
* blk-settings: fix function parameter kernel-doc notationRandy Dunlap2009-10-12
| | | | | | | Fix kernel-doc notation in blk-settings.c::blk_queue_max_discard_sectors(). Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> 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: Do not clamp max_hw_sectors for stacking devicesMartin K. Petersen2009-10-01
| | | | | | | | | Stacking devices do not have an inherent max_hw_sector limit. Set the default to INT_MAX so we are bounded only by capabilities of the underlying storage. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Set max_sectors correctly for stacking devicesMartin K. Petersen2009-10-01
| | | | | | | | | | | The topology changes unintentionally caused SAFE_MAX_SECTORS to be set for stacking devices. Set the default limit to BLK_DEF_MAX_SECTORS and provide SAFE_MAX_SECTORS in blk_queue_make_request() for legacy hw drivers that depend on the old behavior. Acked-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>
* 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: Update topology documentationMartin K. Petersen2009-08-01
| | | | | | | | Update topology comments and sysfs documentation based upon discussions with Neil Brown. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Stack optimal I/O sizeMartin K. Petersen2009-08-01
| | | | | | | | | When stacking block devices ensure that optimal I/O size is scaled accordingly. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> 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>
* block: Make blk_queue_stack_limits use the new stacking interfaceMartin K. Petersen2009-08-01
| | | | | | | | | blk_queue_stack_limits() has been superceded by blk_stack_limits() and disk_stack_limits(). Wrap the function call for now, we'll deprecate it later. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: always assign default lock to queuesJens Axboe2009-07-28
| | | | | | | | | Move the assignment of a default lock below blk_init_queue() to blk_queue_make_request(), so we also get to set the default lock for ->make_request_fn() based drivers. This is important since the queue flag locking requires a lock to be in place. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Fix kernel-doc parameter name typo in blk-settings.c:Randy Dunlap2009-06-19
| | | | | | | | Warning(block/blk-settings.c:108): No description found for parameter 'lim' Warning(block/blk-settings.c:108): Excess function parameter 'limits' description in 'blk_set_default_limits' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: Fix bounce_pfn settingMartin K. Petersen2009-06-18
| | | | | | | | Correct stacking bounce_pfn limit setting and prevent warnings on 32-bit. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> 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>
* block: don't overwrite bdi->state after bdi_init() has been runJens Axboe2009-06-16
| | | | | | Move the defaults to where we do the init of the backing_dev_info. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: fix kernel-doc in recent block/ changesRandy Dunlap2009-06-11
| | | | | | | Fix kernel-doc warnings in recently changed block/ source code. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block: Add missing bounce_pfn stacking and fix commentsMartin K. Petersen2009-06-09
| | | | | | | | | | DM no longer needs to set limits explicitly when calling blk_stack_limits. Let the latter automatically deal with bounce_pfn scaling. Fix kerneldoc variable names. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.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 blk_stack_limits()Mike Snitzer2009-05-28
| | | | | | | | DM needs to use blk_stack_limits(), so it needs to be exported. Acked-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>
* block: fix queue bounce limit settingTejun Heo2009-04-22
| | | | | | | | | | | | | | | | | | | Impact: don't set GFP_DMA in q->bounce_gfp unnecessarily All DMA address limits are expressed in terms of the last addressable unit (byte or page) instead of one plus that. However, when determining bounce_gfp for 64bit machines in blk_queue_bounce_limit(), it compares the specified limit against 0x100000000UL to determine whether it's below 4G ending up falsely setting GFP_DMA in q->bounce_gfp. As DMA zone is very small on x86_64, this makes larger SG_IO transfers very eager to trigger OOM killer. Fix it. While at it, rename the parameter to @dma_mask for clarity and convert comment to proper winged style. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* pata_artop: typoAlan Cox2009-04-06
| | | | | | | | Fix a typo (this was in the original patch but was not merged when the code fixes were for some reason) Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* block: use min_not_zero in blk_queue_stack_limitsFUJITA Tomonori2008-12-29
| | | | | | | | | | | | | | | zero is invalid for max_phys_segments, max_hw_segments, and max_segment_size. It's better to use use min_not_zero instead of min. min() works though (because the commit 0e435ac makes sure that these values are set to the default values, non zero, if a queue is initialized properly). With this patch, blk_queue_stack_limits does the almost same thing that dm's combine_restrictions_low() does. I think that it's easy to remove dm's combine_restrictions_low. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: fix setting of max_segment_size and seg_boundary maskMilan Broz2008-12-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix setting of max_segment_size and seg_boundary mask for stacked md/dm devices. When stacking devices (LVM over MD over SCSI) some of the request queue parameters are not set up correctly in some cases by default, namely max_segment_size and and seg_boundary mask. If you create MD device over SCSI, these attributes are zeroed. Problem become when there is over this mapping next device-mapper mapping - queue attributes are set in DM this way: request_queue max_segment_size seg_boundary_mask SCSI 65536 0xffffffff MD RAID1 0 0 LVM 65536 -1 (64bit) Unfortunately bio_add_page (resp. bio_phys_segments) calculates number of physical segments according to these parameters. During the generic_make_request() is segment cout recalculated and can increase bio->bi_phys_segments count over the allowed limit. (After bio_clone() in stack operation.) Thi is specially problem in CCISS driver, where it produce OOPS here BUG_ON(creq->nr_phys_segments > MAXSGENTRIES); (MAXSEGENTRIES is 31 by default.) Sometimes even this command is enough to cause oops: dd iflag=direct if=/dev/<vg>/<lv> of=/dev/null bs=128000 count=10 This command generates bios with 250 sectors, allocated in 32 4k-pages (last page uses only 1024 bytes). For LVM layer, it allocates bio with 31 segments (still OK for CCISS), unfortunatelly on lower layer it is recalculated to 32 segments and this violates CCISS restriction and triggers BUG_ON(). The patch tries to fix it by: * initializing attributes above in queue request constructor blk_queue_make_request() * make sure that blk_queue_stack_limits() inherits setting (DM uses its own function to set the limits because it blk_queue_stack_limits() was introduced later. It should probably switch to use generic stack limit function too.) * sets the default seg_boundary value in one place (blkdev.h) * use this mask as default in DM (instead of -1, which differs in 64bit) Bugs related to this: https://bugzilla.redhat.com/show_bug.cgi?id=471639 http://bugzilla.kernel.org/show_bug.cgi?id=8672 Signed-off-by: Milan Broz <mbroz@redhat.com> Reviewed-by: Alasdair G Kergon <agk@redhat.com> Cc: Neil Brown <neilb@suse.de> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Tejun Heo <htejun@gmail.com> Cc: Mike Miller <mike.miller@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: move q->unplug_work initializationPeter Zijlstra2008-10-17
| | | | | | | | | | | | | modprobe loop; rmmod loop effectively creates a blk_queue and destroys it which results in q->unplug_work being canceled without it ever being initialized. Therefore, move the initialization of q->unplug_work from blk_queue_make_request() to blk_alloc_queue*(). Reported-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: add lld busy state exporting interfaceKiyoshi Ueda2008-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds an new interface, blk_lld_busy(), to check lld's busy state from the block layer. blk_lld_busy() calls down into low-level drivers for the checking if the drivers set q->lld_busy_fn() using blk_queue_lld_busy(). This resolves a performance problem on request stacking devices below. Some drivers like scsi mid layer stop dispatching request when they detect busy state on its low-level device like host/target/device. It allows other requests to stay in the I/O scheduler's queue for a chance of merging. Request stacking drivers like request-based dm should follow the same logic. However, there is no generic interface for the stacked device to check if the underlying device(s) are busy. If the request stacking driver dispatches and submits requests to the busy underlying device, the requests will stay in the underlying device's queue without a chance of merging. This causes performance problem on burst I/O load. With this patch, busy state of the underlying device is exported via q->lld_busy_fn(). So the request stacking driver can check it and stop dispatching requests if busy. The underlying device driver must return the busy state appropriately: 1: when the device driver can't process requests immediately. 0: when the device driver can process requests immediately, including abnormal situations where the device driver needs to kill all requests. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: unify request timeout handlingJens Axboe2008-10-09
| | | | | | | | | | | | | Right now SCSI and others do their own command timeout handling. Move those bits to the block layer. Instead of having a timer per command, we try to be a bit more clever and simply have one per-queue. This avoids the overhead of having to tear down and setup a timer for each command, so it will result in a lot less timer fiddling. Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: kmalloc args reversed, small function definition fixesHarvey Harrison2008-10-09
| | | | | | | | | | | | | | | | Noticed by sparse: block/blk-softirq.c:156:12: warning: symbol 'blk_softirq_init' was not declared. Should it be static? block/genhd.c:583:28: warning: function 'bdget_disk' with external linkage has definition block/genhd.c:659:17: warning: incorrect type in argument 1 (different base types) block/genhd.c:659:17: expected unsigned int [unsigned] [usertype] size block/genhd.c:659:17: got restricted gfp_t block/genhd.c:659:29: warning: incorrect type in argument 2 (different base types) block/genhd.c:659:29: expected restricted gfp_t [usertype] flags block/genhd.c:659:29: got unsigned int block: kmalloc args reversed Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: add support for IO CPU affinityJens Axboe2008-10-09
| | | | | | | | | | | | | | | | | | This patch adds support for controlling the IO completion CPU of either all requests on a queue, or on a per-request basis. We export a sysfs variable (rq_affinity) which, if set, migrates completions of requests to the CPU that originally submitted it. A bio helper (bio_set_completion_cpu()) is also added, so that queuers can ask for completion on that specific CPU. In testing, this has been show to cut the system time by as much as 20-40% on synthetic workloads where CPU affinity is desired. This requires a little help from the architecture, so it'll only work as designed for archs that are using the new generic smp helper infrastructure. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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