talos-op-linux/block/blk-settings.c, branch v4.2.2

sd: Fix maximum I/O size for BLOCK_PC requests

2015-08-12T18:54:37+00:00

Commit bcdb247c6b6a ("sd: Limit transfer length") clamped the maximum size of an I/O request to the MAXIMUM TRANSFER LENGTH field in the BLOCK LIMITS VPD. This had the unfortunate effect of also limiting the maximum size of non-filesystem requests sent to the device through sg/bsg. Avoid using blk_queue_max_hw_sectors() and set the max_sectors queue limit directly. Also update the comment in blk_limits_max_hw_sectors() to clarify that max_hw_sectors defines the limit for the I/O controller only. Signed-off-by: Martin K. Petersen Reported-by: Brian King Tested-by: Brian King Cc: stable@vger.kernel.org # 3.17+ Signed-off-by: James Bottomley

block: fix blk_stack_limits() regression due to lcm() change

2015-03-31T15:45:50+00:00

Linux 3.19 commit 69c953c ("lib/lcm.c: lcm(n,0)=lcm(0,n) is 0, not n") caused blk_stack_limits() to not properly stack queue_limits for stacked devices (e.g. DM). Fix this regression by establishing lcm_not_zero() and switching blk_stack_limits() over to using it. DM uses blk_set_stacking_limits() to establish the initial top-level queue_limits that are then built up based on underlying devices' limits using blk_stack_limits(). In the case of optimal_io_size (io_opt) blk_set_stacking_limits() establishes a default value of 0. With commit 69c953c, lcm(0, n) is no longer n, which compromises proper stacking of the underlying devices' io_opt. Test: $ modprobe scsi_debug dev_size_mb=10 num_tgts=1 opt_blks=1536 $ cat /sys/block/sde/queue/optimal_io_size 786432 $ dmsetup create node --table "0 100 linear /dev/sde 0" Before this fix: $ cat /sys/block/dm-5/queue/optimal_io_size 0 After this fix: $ cat /sys/block/dm-5/queue/optimal_io_size 786432 Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org # 3.19+ Acked-by: Martin K. Petersen Signed-off-by: Jens Axboe

block: remove artifical max_hw_sectors cap

2014-10-21T20:02:54+00:00

Set max_sectors to the value the drivers provides as hardware limit by default. Linux had proper I/O throttling for a long time and doesn't rely on a artifically small maximum I/O size anymore. By not limiting the I/O size by default we remove an annoying tuning step required for most Linux installation. Note that both the user, and if absolutely required the driver can still impose a limit for FS requests below max_hw_sectors_kb. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: fix alignment_offset math that assumes io_min is a power-of-2

2014-10-09T15:41:40+00:00

The math in both blk_stack_limits() and queue_limit_alignment_offset() assume that a block device's io_min (aka minimum_io_size) is always a power-of-2. Fix the math such that it works for non-power-of-2 io_min. This issue (of alignment_offset != 0) became apparent when testing dm-thinp with a thinp blocksize that matches a RAID6 stripesize of 1280K. Commit fdfb4c8c1 ("dm thin: set minimum_io_size to pool's data block size") unlocked the potential for alignment_offset != 0 due to the dm-thin-pool's io_min possibly being a non-power-of-2. Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org Acked-by: Martin K. Petersen Signed-off-by: Jens Axboe

block: ensure that bio_add_page() always accepts a page for an empty bio

2014-06-10T18:53:56+00:00

With commit 762380ad9322 added support for chunk sizes and no merging across them, it broke the rule of always allowing adding of a single page to an empty bio. So relax the restriction a bit to allow for that, similarly to what we have always done. This fixes a crash with mkfs.xfs and 512b sector sizes on NVMe. Reported-by: Keith Busch Signed-off-by: Jens Axboe

block: add notion of a chunk size for request merging

2014-06-05T19:38:39+00:00

Some drivers have different limits on what size a request should optimally be, depending on the offset of the request. Similar to dividing a device into chunks. Add a setting that allows the driver to inform the block layer of such a chunk size. The block layer will then prevent merging across the chunks. This is needed to optimally support NVMe with a non-zero stripe size. Signed-off-by: Jens Axboe

bcache/md: Use raid stripe size

2014-01-08T21:05:09+00:00

Now that we've got code for raid5/6 stripe awareness, bcache just needs to know about the stripes and when writing partial stripes is expensive - we probably don't want to enable this optimization for raid1 or 10, even though they have stripes. So add a flag to queue_limits. Signed-off-by: Kent Overstreet

Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block

2013-11-14T03:08:14+00:00

Pull block IO core updates from Jens Axboe: "This is the pull request for the core changes in the block layer for 3.13. It contains: - The new blk-mq request interface. This is a new and more scalable queueing model that marries the best part of the request based interface we currently have (which is fully featured, but scales poorly) and the bio based "interface" which the new drivers for high IOPS devices end up using because it's much faster than the request based one. The bio interface has no block layer support, since it taps into the stack much earlier. This means that drivers end up having to implement a lot of functionality on their own, like tagging, timeout handling, requeue, etc. The blk-mq interface provides all these. Some drivers even provide a switch to select bio or rq and has code to handle both, since things like merging only works in the rq model and hence is faster for some workloads. This is a huge mess. Conversion of these drivers nets us a substantial code reduction. Initial results on converting SCSI to this model even shows an 8x improvement on single queue devices. So while the model was intended to work on the newer multiqueue devices, it has substantial improvements for "classic" hardware as well. This code has gone through extensive testing and development, it's now ready to go. A pull request is coming to convert virtio-blk to this model will be will be coming as well, with more drivers scheduled for 3.14 conversion. - Two blktrace fixes from Jan and Chen Gang. - A plug merge fix from Alireza Haghdoost. - Conversion of __get_cpu_var() from Christoph Lameter. - Fix for sector_div() with 64-bit divider from Geert Uytterhoeven. - A fix for a race between request completion and the timeout handling from Jeff Moyer. This is what caused the merge conflict with blk-mq/core, in case you are looking at that. - A dm stacking fix from Mike Snitzer. - A code consolidation fix and duplicated code removal from Kent Overstreet. - A handful of block bug fixes from Mikulas Patocka, fixing a loop crash and memory corruption on blk cg. - Elevator switch bug fix from Tomoki Sekiyama. A heads-up that I had to rebase this branch. Initially the immutable bio_vecs had been queued up for inclusion, but a week later, it became clear that it wasn't fully cooked yet. So the decision was made to pull this out and postpone it until 3.14. It was a straight forward rebase, just pruning out the immutable series and the later fixes of problems with it. The rest of the patches applied directly and no further changes were made" * 'for-3.13/core' of git://git.kernel.dk/linux-block: (31 commits) block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO block: Do not call sector_div() with a 64-bit divisor kernel: trace: blktrace: remove redundent memcpy() in compat_blk_trace_setup() block: Consolidate duplicated bio_trim() implementations block: Use rw_copy_check_uvector() block: Enable sysfs nomerge control for I/O requests in the plug list block: properly stack underlying max_segment_size to DM device elevator: acquire q->sysfs_lock in elevator_change() elevator: Fix a race in elevator switching and md device initialization block: Replace __get_cpu_var uses bdi: test bdi_init failure block: fix a probe argument to blk_register_region loop: fix crash if blk_alloc_queue fails blk-core: Fix memory corruption if blkcg_init_queue fails block: fix race between request completion and timeout handling blktrace: Send BLK_TN_PROCESS events to all running traces blk-mq: don't disallow request merges for req->special being set blk-mq: mq plug list breakage blk-mq: fix for flush deadlock ...

block: properly stack underlying max_segment_size to DM device

2013-11-08T16:00:17+00:00

Without this patch all DM devices will default to BLK_MAX_SEGMENT_SIZE (65536) even if the underlying device(s) have a larger value -- this is due to blk_stack_limits() using min_not_zero() when stacking the max_segment_size limit. 1073741824 before patch: 65536 after patch: 1073741824 Reported-by: Lukasz Flis Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org # v3.3+ Signed-off-by: Jens Axboe

ARM: 7794/1: block: Rename parameter dma_mask to max_addr for blk_queue_bounce_limit()

2013-10-31T14:49:22+00:00

The blk_queue_bounce_limit() API parameter 'dma_mask' is actually the maximum address the device can handle rather than a dma_mask. Rename it accordingly to avoid it being interpreted as dma_mask. No functional change. The idea is to fix the bad assumptions about dma_mask wherever it could be miss-interpreted. Cc: Jens Axboe Signed-off-by: Santosh Shilimkar Signed-off-by: Russell King