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2016-04-15Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "A few fixes for the current series. This contains: - Two fixes for NVMe: One fixes a reset race that can be triggered by repeated insert/removal of the module. The other fixes an issue on some platforms, where we get probe timeouts since legacy interrupts isn't working. This used not to be a problem since we had the worker thread poll for completions, but since that was killed off, it means those poor souls can't successfully probe their NVMe device. Use a proper IRQ check and probe (msi-x -> msi ->legacy), like most other drivers to work around this. Both from Keith. - A loop corruption issue with offset in iters, from Ming Lei. - A fix for not having the partition stat per cpu ref count initialized before sending out the KOBJ_ADD, which could cause user space to access the counter prior to initialization. Also from Ming Lei. - A fix for using the wrong congestion state, from Kaixu Xia" * 'for-linus' of git://git.kernel.dk/linux-block: block: loop: fix filesystem corruption in case of aio/dio NVMe: Always use MSI/MSI-x interrupts NVMe: Fix reset/remove race writeback: fix the wrong congested state variable definition block: partition: initialize percpuref before sending out KOBJ_ADD
2016-04-04mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usageKirill A. Shutemov
Mostly direct substitution with occasional adjustment or removing outdated comments. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-29block: partition: initialize percpuref before sending out KOBJ_ADDMing Lei
The initialization of partition's percpu_ref should have been done before sending out KOBJ_ADD uevent, which may cause userspace to read partition table. So the uninitialized percpu_ref may be accessed in data path. This patch fixes this issue reported by Naveen. Reported-by: Naveen Kaje <nkaje@codeaurora.org> Tested-by: Naveen Kaje <nkaje@codeaurora.org> Fixes: 6c71013ecb7e2(block: partition: convert percpu ref) Cc: <stable@vger.kernel.org> # v4.3+ Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-24Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "Final round of fixes for this merge window - some of this has come up after the initial pull request, and some of it was put in a post-merge branch before the merge window. This contains: - Fix for a bad check for an error on dma mapping in the mtip32xx driver, from Alexey Khoroshilov. - A set of fixes for lightnvm, from Javier, Matias, and Wenwei. - An NVMe completion record corruption fix from Marta, ensuring that we read things in the right order. - Two writeback fixes from Tejun, marked for stable@ as well. - A blk-mq sw queue iterator fix from Thomas, fixing an oops for sparse CPU maps. They hit this in the hot plug/unplug rework" * 'for-linus' of git://git.kernel.dk/linux-block: nvme: avoid cqe corruption when update at the same time as read writeback, cgroup: fix use of the wrong bdi_writeback which mismatches the inode writeback, cgroup: fix premature wb_put() in locked_inode_to_wb_and_lock_list() blk-mq: Use proper cpumask iterator mtip32xx: fix checks for dma mapping errors lightnvm: do not load L2P table if not supported lightnvm: do not reserve lun on l2p loading nvme: lightnvm: return ppa completion status lightnvm: add a bitmap of luns lightnvm: specify target's logical address area null_blk: add lightnvm null_blk device to the nullb_list
2016-03-20blk-mq: Use proper cpumask iteratorThomas Gleixner
queue_for_each_ctx() iterates over per_cpu variables under the assumption that the possible cpu mask cannot have holes. That's wrong as all cpumasks can have holes. In case there are holes the iteration ends up accessing uninitialized memory and crashing as a result. Replace the macro by a proper for_each_possible_cpu() loop and drop the unused macro blk_ctx_sum() which references queue_for_each_ctx(). Reported-by: Xiong Zhou <jencce.kernel@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-18Merge branch 'for-4.6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata Pull libata updates from Tejun Heo: - ahci grew runtime power management support so that the controller can be turned off if no devices are attached. - sata_via isn't dead yet. It got hotplug support and more refined workaround for certain WD drives. - Misc cleanups. There's a merge from for-4.5-fixes to avoid confusing conflicts in ahci PCI ID table. * 'for-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata: ata: ahci_xgene: dereferencing uninitialized pointer in probe AHCI: Remove obsolete Intel Lewisburg SATA RAID device IDs ata: sata_rcar: Use ARCH_RENESAS sata_via: Implement hotplug for VT6421 sata_via: Apply WD workaround only when needed on VT6421 ahci: Add runtime PM support for the host controller ahci: Add functions to manage runtime PM of AHCI ports ahci: Convert driver to use modern PM hooks ahci: Cache host controller version scsi: Drop runtime PM usage count after host is added scsi: Set request queue runtime PM status back to active on resume block: Add blk_set_runtime_active() ata: ahci_mvebu: add support for Armada 3700 variant libata: fix unbalanced spin_lock_irqsave/spin_unlock_irq() in ata_scsi_park_show() libata: support AHCI on OCTEON platform
2016-03-18Merge branch 'for-4.6/core' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block updates from Jens Axboe: "Here are the core block changes for this merge window. Not a lot of exciting stuff going on in this round, most of the changes have been on the driver side of things. That pull request is coming next. This pull request contains: - A set of fixes for chained bio handling from Christoph. - A tag bounds check for blk-mq from Hannes, ensuring that we don't do something stupid if a device reports an invalid tag value. - A set of fixes/updates for the CFQ IO scheduler from Jan Kara. - A set of blk-mq fixes from Keith, adding support for dynamic hardware queues, and fixing init of max_dev_sectors for stacking devices. - A fix for the dynamic hw context from Ming. - Enabling of cgroup writeback support on a block device, from Shaohua" * 'for-4.6/core' of git://git.kernel.dk/linux-block: blk-mq: add bounds check on tag-to-rq conversion block: bio_remaining_done() isn't unlikely block: cleanup bio_endio block: factor out chained bio completion block: don't unecessarily clobber bi_error for chained bios block-dev: enable writeback cgroup support blk-mq: Fix NULL pointer updating nr_requests blk-mq: mark request queue as mq asap block: Initialize max_dev_sectors to 0 blk-mq: dynamic h/w context count cfq-iosched: Allow parent cgroup to preempt its child cfq-iosched: Allow sync noidle workloads to preempt each other cfq-iosched: Reorder checks in cfq_should_preempt() cfq-iosched: Don't group_idle if cfqq has big thinktime
2016-03-16Merge tag 'dm-4.6-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - Most attention this cycle went to optimizing blk-mq request-based DM (dm-mq) that is used exclussively by DM multipath: - A stable fix for dm-mq that eliminates excessive context switching offers the biggest performance improvement (for both IOPs and throughput). - But more work is needed, during the next cycle, to reduce spinlock contention in DM multipath on large NUMA systems. - A stable fix for a NULL pointer seen when DM stats is enabled on a DM multipath device that must requeue an IO due to path failure. - A stable fix for DM snapshot to disallow the COW and origin devices from being identical. This amounts to graceful failure in the face of userspace error because these devices shouldn't ever be identical. - Stable fixes for DM cache and DM thin provisioning to address crashes seen if/when their respective metadata device experiences failures that cause the transition to 'fail_io' mode. - The DM cache 'mq' policy is now an alias for the 'smq' policy. The 'smq' policy proved to be consistently better than 'mq'. As such 'mq', with all its complex user-facing tunables, has been eliminated. - Improve DM thin provisioning to consistently return -ENOSPC once the thin-pool's data volume is out of space. - Improve DM core to properly handle error propagation if bio_integrity_clone() fails in clone_bio(). - Other small cleanups and improvements to DM core. * tag 'dm-4.6-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (41 commits) dm: fix rq_end_stats() NULL pointer in dm_requeue_original_request() dm thin: consistently return -ENOSPC if pool has run out of data space dm cache: bump the target version dm cache: make sure every metadata function checks fail_io dm: add missing newline between DM_DEBUG_BLOCK_STACK_TRACING and DM_BUFIO dm cache policy smq: clarify that mq registration failure was for 'mq' dm: return error if bio_integrity_clone() fails in clone_bio() dm thin metadata: don't issue prefetches if a transaction abort has failed dm snapshot: disallow the COW and origin devices from being identical dm cache: make the 'mq' policy an alias for 'smq' dm: drop unnecessary assignment of md->queue dm: reorder 'struct mapped_device' members to fix alignment and holes dm: remove dummy definition of 'struct dm_table' dm: add 'dm_numa_node' module parameter dm thin metadata: remove needless newline from subtree_dec() DMERR message dm mpath: cleanup reinstate_path() et al based on code review dm mpath: remove __pgpath_busy forward declaration, rename to pgpath_busy dm mpath: switch from 'unsigned' to 'bool' for flags where appropriate dm round robin: use percpu 'repeat_count' and 'current_path' dm path selector: remove 'repeat_count' return from .select_path hook ...
2016-03-15block: partition: add partition specific uevent callbacks for partition infoSan Mehat
This patch has been carried in the Android tree for quite some time and is one of the few patches required to get a mainline kernel up and running with an exsiting Android userspace. So I wanted to submit it for review and consideration if it should be merged. For partitions, add new uevent parameters 'PARTN' which specifies the partitions index in the table, and 'PARTNAME', which specifies PARTNAME specifices the partition name of a partition device. Android's userspace uses this for creating device node links from the partition name and number, ie: /dev/block/platform/soc/by-name/system or /dev/block/platform/soc/by-num/p1 One can see its usage here: https://android.googlesource.com/platform/system/core/+/master/init/devices.cpp#355 and https://android.googlesource.com/platform/system/core/+/master/init/devices.cpp#494 [john.stultz@linaro.org: dropped NPARTS and reworded commit message for context] Signed-off-by: Dima Zavin <dima@android.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Rom Lemarchand <romlem@google.com> Cc: Android Kernel Team <kernel-team@android.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: <harald@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15blk-mq: add bounds check on tag-to-rq conversionHannes Reinecke
We need to check for a valid index before accessing the array element to avoid accessing invalid memory regions. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Modified by Jens to drop the unlikely(), and make the fall through path be having a valid tag. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-14block: bio_remaining_done() isn't unlikelyChristoph Hellwig
We use bio chaining during most I/Os these days due to the delayed bio splitting. Additionally XFS will start using it, and there is a pending direct I/O rewrite also making heavy use for it. Don't pretend it's always unlikely, and let the branch predictor do it's job instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-14block: cleanup bio_endioChristoph Hellwig
Replace the while loop that unecessarily checks for a NULL bio in the fast path with a simple goto loop. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-14block: factor out chained bio completionChristoph Hellwig
Factor common code between bio_chain_endio and bio_endio into a common helper. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-14block: don't unecessarily clobber bi_error for chained biosChristoph Hellwig
Only overwrite the parents bi_error if it was zero. That way a successful bio completion doesn't reset the error pointer. Reported-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-03blk-mq: Fix NULL pointer updating nr_requestsKeith Busch
A h/w context's tags are freed if it was not assigned a CPU. Check if the context has tags before updating the depth. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-03block: support large requests in blk_rq_map_user_iovChristoph Hellwig
This patch adds support for larger requests in blk_rq_map_user_iov by allowing it to build multiple bios for a request. This functionality used to exist for the non-vectored blk_rq_map_user in the past, and this patch reuses the existing functionality for it on the unmap side, which stuck around. Thanks to the iov_iter API supporting multiple bios is fairly trivial, as we can just iterate the iov until we've consumed the whole iov_iter. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Jeff Lien <Jeff.Lien@hgst.com> Tested-by: Jeff Lien <Jeff.Lien@hgst.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-03block: merge: get the 1st and last bvec via helpersMing Lei
This patch applies the two introduced helpers to figure out the 1st and last bvec. Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-27block: disable block device DAX by defaultDan Williams
The recent *sync enabling discovered that we are inserting into the block_device pagecache counter to the expectations of the dirty data tracking for dax mappings. This can lead to data corruption. We want to support DAX for block devices eventually, but it requires wider changes to properly manage the pagecache. dump_stack+0x85/0xc2 dax_writeback_mapping_range+0x60/0xe0 blkdev_writepages+0x3f/0x50 do_writepages+0x21/0x30 __filemap_fdatawrite_range+0xc6/0x100 filemap_write_and_wait+0x4a/0xa0 set_blocksize+0x70/0xd0 sb_set_blocksize+0x1d/0x50 ext4_fill_super+0x75b/0x3360 mount_bdev+0x180/0x1b0 ext4_mount+0x15/0x20 mount_fs+0x38/0x170 Mark the support broken so its disabled by default, but otherwise still available for testing. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com> Suggested-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@fb.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-22dm: fix excessive dm-mq context switchingMike Snitzer
Request-based DM's blk-mq support (dm-mq) was reported to be 50% slower than if an underlying null_blk device were used directly. One of the reasons for this drop in performance is that blk_insert_clone_request() was calling blk_mq_insert_request() with @async=true. This forced the use of kblockd_schedule_delayed_work_on() to run the blk-mq hw queues which ushered in ping-ponging between process context (fio in this case) and kblockd's kworker to submit the cloned request. The ftrace function_graph tracer showed: kworker-2013 => fio-12190 fio-12190 => kworker-2013 ... kworker-2013 => fio-12190 fio-12190 => kworker-2013 ... Fixing blk_insert_clone_request()'s blk_mq_insert_request() call to _not_ use kblockd to submit the cloned requests isn't enough to eliminate the observed context switches. In addition to this dm-mq specific blk-core fix, there are 2 DM core fixes to dm-mq that (when paired with the blk-core fix) completely eliminate the observed context switching: 1) don't blk_mq_run_hw_queues in blk-mq request completion Motivated by desire to reduce overhead of dm-mq, punting to kblockd just increases context switches. In my testing against a really fast null_blk device there was no benefit to running blk_mq_run_hw_queues() on completion (and no other blk-mq driver does this). So hopefully this change doesn't induce the need for yet another revert like commit 621739b00e16ca2d ! 2) use blk_mq_complete_request() in dm_complete_request() blk_complete_request() doesn't offer the traditional q->mq_ops vs .request_fn branching pattern that other historic block interfaces do (e.g. blk_get_request). Using blk_mq_complete_request() for blk-mq requests is important for performance. It should be noted that, like blk_complete_request(), blk_mq_complete_request() doesn't natively handle partial completions -- but the request-based DM-multipath target does provide the required partial completion support by dm.c:end_clone_bio() triggering requeueing of the request via dm-mpath.c:multipath_end_io()'s return of DM_ENDIO_REQUEUE. dm-mq fix #2 is _much_ more important than #1 for eliminating the context switches. Before: cpu : usr=15.10%, sys=59.39%, ctx=7905181, majf=0, minf=475 After: cpu : usr=20.60%, sys=79.35%, ctx=2008, majf=0, minf=472 With these changes multithreaded async read IOPs improved from ~950K to ~1350K for this dm-mq stacked on null_blk test-case. The raw read IOPs of the underlying null_blk device for the same workload is ~1950K. Fixes: 7fb4898e0 ("block: add blk-mq support to blk_insert_cloned_request()") Fixes: bfebd1cdb ("dm: add full blk-mq support to request-based DM") Cc: stable@vger.kernel.org # 4.1+ Reported-by: Sagi Grimberg <sagig@dev.mellanox.co.il> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Jens Axboe <axboe@kernel.dk>
2016-02-19block: Add blk_set_runtime_active()Mika Westerberg
If block device is left runtime suspended during system suspend, resume hook of the driver typically corrects runtime PM status of the device back to "active" after it is resumed. However, this is not enough as queue's runtime PM status is still "suspended". As long as it is in this state blk_pm_peek_request() returns NULL and thus prevents new requests to be processed. Add new function blk_set_runtime_active() that can be used to force the queue status back to "active" as needed. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-17Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "A collection of fixes from the past few weeks that should go into 4.5. This contains: - Overflow fix for sysfs discard show function from Alan. - A stacking limit init fix for max_dev_sectors, so we don't end up artificially capping some use cases. From Keith. - Have blk-mq proper end unstarted requests on a dying queue, instead of pushing that to the driver. From Keith. - NVMe: - Update to Kconfig description for NVME_SCSI, since it was vague and having it on is important for some SUSE distros. From Christoph. - Set of fixes from Keith, around surprise removal. Also kills the no-merge flag, so it supports merging. - Set of fixes for lightnvm from Matias, Javier, and Wenwei. - Fix null_blk oops when asked for lightnvm, but not available. From Matias. - Copy-to-user EINTR fix from Hannes, fixing a case where SG_IO fails if interrupted by a signal. - Two floppy fixes from Jiri, fixing signal handling and blocking open. - A use-after-free fix for O_DIRECT, from Mike Krinkin. - A block module ref count fix from Roman Pen. - An fs IO wait accounting fix for O_DSYNC from Stephane Gasparini. - Smaller reallo fix for xen-blkfront from Bob Liu. - Removal of an unused struct member in the deadline IO scheduler, from Tahsin. - Also from Tahsin, properly initialize inode struct members associated with cgroup writeback, if enabled. - From Tejun, ensure that we keep the superblock pinned during cgroup writeback" * 'for-linus' of git://git.kernel.dk/linux-block: (25 commits) blk: fix overflow in queue_discard_max_hw_show writeback: initialize inode members that track writeback history writeback: keep superblock pinned during cgroup writeback association switches bio: return EINTR if copying to user space got interrupted NVMe: Rate limit nvme IO warnings NVMe: Poll device while still active during remove NVMe: Requeue requests on suspended queues NVMe: Allow request merges NVMe: Fix io incapable return values blk-mq: End unstarted requests on dying queue block: Initialize max_dev_sectors to 0 null_blk: oops when initializing without lightnvm block: fix module reference leak on put_disk() call for cgroups throttle nvme: fix Kconfig description for BLK_DEV_NVME_SCSI kernel/fs: fix I/O wait not accounted for RW O_DSYNC floppy: refactor open() flags handling lightnvm: allow to force mm initialization lightnvm: check overflow and correct mlc pairs lightnvm: fix request intersection locking in rrpc lightnvm: warn if irqs are disabled in lock laddr ...
2016-02-17blk: fix overflow in queue_discard_max_hw_showAlan
We get this right for queue_discard_max_show but not max_hw_show. Follow the same pattern as queue_discard_max_show instead so that we don't truncate. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-14blk-mq: mark request queue as mq asapMing Lei
Currently q->mq_ops is used widely to decide if the queue is mq or not, so we should set the 'flag' asap so that both block core and drivers can get the correct mq info. For example, commit 868f2f0b720(blk-mq: dynamic h/w context count) moves the hctx's initialization before setting q->mq_ops in blk_mq_init_allocated_queue(), then cause blk_alloc_flush_queue() to think the queue is non-mq and don't allocate command size for the per-hctx flush rq. This patches should fix the problem reported by Sasha. Cc: Keith Busch <keith.busch@intel.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Fixes: 868f2f0b720 ("blk-mq: dynamic h/w context count") Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-12Merge tag 'scsi-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi Pull SCSI fixes from James Bottomley: "A set of seven fixes: Two regressions in the new hisi_sas arm driver, a blacklist entry for the marvell console which was causing a reset cascade without it, a race fix in the WRITE_SAME/DISCARD routines, a retry fix for the rdac driver, without which, it would prematurely return EIO and a couple of fixes for the hyper-v storvsc driver" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: block/sd: Return -EREMOTEIO when WRITE SAME and DISCARD are disabled SCSI: Add Marvell Console to VPD blacklist scsi_dh_rdac: always retry MODE SELECT on command lock violation storvsc: Use the specified target ID in device lookup storvsc: Install the storvsc specific timeout handler for FC devices hisi_sas: fix v1 hw check for slot error hisi_sas: add dependency for HAS_IOMEM
2016-02-12bio: return EINTR if copying to user space got interruptedHannes Reinecke
Commit 35dc248383bbab0a7203fca4d722875bc81ef091 introduced a check for current->mm to see if we have a user space context and only copies data if we do. Now if an IO gets interrupted by a signal data isn't copied into user space any more (as we don't have a user space context) but user space isn't notified about it. This patch modifies the behaviour to return -EINTR from bio_uncopy_user() to notify userland that a signal has interrupted the syscall, otherwise it could lead to a situation where the caller may get a buffer with no data returned. This can be reproduced by issuing SG_IO ioctl()s in one thread while constantly sending signals to it. Fixes: 35dc248 [SCSI] sg: Fix user memory corruption when SG_IO is interrupted by a signal Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Hannes Reinecke <hare@suse.de> Cc: stable@vger.kernel.org # v.3.11+ Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-11blk-mq: End unstarted requests on dying queueKeith Busch
Go directly to ending a request if it wasn't started. Previously, completing a request may invoke a driver callback for a request it didn't initialize. Signed-off-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Johannes Thumshirn <jthumshirn at suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-11block: Initialize max_dev_sectors to 0Keith Busch
The new queue limit is not used by the majority of block drivers, and should be initialized to 0 for the driver's requested settings to be used. Signed-off-by: Keith Busch <keith.busch@intel.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-11block: Initialize max_dev_sectors to 0Keith Busch
The new queue limit is not used by the majority of block drivers, and should be initialized to 0 for the driver's requested settings to be used. Signed-off-by: Keith Busch <keith.busch@intel.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-09blk-mq: dynamic h/w context countKeith Busch
The hardware's provided queue count may change at runtime with resource provisioning. This patch allows a block driver to alter the number of h/w queues available when its resource count changes. The main part is a new blk-mq API to request a new number of h/w queues for a given live tag set. The new API freezes all queues using that set, then adjusts the allocated count prior to remapping these to CPUs. The bulk of the rest just shifts where h/w contexts and all their artifacts are allocated and freed. The number of max h/w contexts is capped to the number of possible cpus since there is no use for more than that. As such, all pre-allocated memory for pointers need to account for the max possible rather than the initial number of queues. A side effect of this is that the blk-mq will proceed successfully as long as it can allocate at least one h/w context. Previously it would fail request queue initialization if less than the requested number was allocated. Signed-off-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Jon Derrick <jonathan.derrick@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-09block: fix module reference leak on put_disk() call for cgroups throttleRoman Pen
get_disk(),get_gendisk() calls have non explicit side effect: they increase the reference on the disk owner module. The following is the correct sequence how to get a disk reference and to put it: disk = get_gendisk(...); /* use disk */ owner = disk->fops->owner; put_disk(disk); module_put(owner); fs/block_dev.c is aware of this required module_put() call, but f.e. blkg_conf_finish(), which is located in block/blk-cgroup.c, does not put a module reference. To see a leakage in action cgroups throttle config can be used. In the following script I'm removing throttle for /dev/ram0 (actually this is NOP, because throttle was never set for this device): # lsmod | grep brd brd 5175 0 # i=100; while [ $i -gt 0 ]; do echo "1:0 0" > \ /sys/fs/cgroup/blkio/blkio.throttle.read_bps_device; i=$(($i - 1)); \ done # lsmod | grep brd brd 5175 100 Now brd module has 100 references. The issue is fixed by calling module_put() just right away put_disk(). Signed-off-by: Roman Pen <roman.penyaev@profitbricks.com> Cc: Gi-Oh Kim <gi-oh.kim@profitbricks.com> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-09kernel/fs: fix I/O wait not accounted for RW O_DSYNCStephane Gasparini
When a process is doing Random Write with O_DSYNC flag the I/O wait are not accounted in the kernel (get_cpu_iowait_time_us). This is preventing the governor or the cpufreq driver to account for I/O wait and thus use the right pstate Signed-off-by: Stephane Gasparini <stephane.gasparini@linux.intel.com> Signed-off-by: Philippe Longepe <philippe.longepe@linux.intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-04Merge remote-tracking branch 'mkp-scsi/4.5/scsi-fixes' into fixesJames Bottomley
2016-02-04block/sd: Return -EREMOTEIO when WRITE SAME and DISCARD are disabledMartin K. Petersen
When a storage device rejects a WRITE SAME command we will disable write same functionality for the device and return -EREMOTEIO to the block layer. -EREMOTEIO will in turn prevent DM from retrying the I/O and/or failing the path. Yiwen Jiang discovered a small race where WRITE SAME requests issued simultaneously would cause -EIO to be returned. This happened because any requests being prepared after WRITE SAME had been disabled for the device caused us to return BLKPREP_KILL. The latter caused the block layer to return -EIO upon completion. To overcome this we introduce BLKPREP_INVALID which indicates that this is an invalid request for the device. blk_peek_request() is modified to return -EREMOTEIO in that case. Reported-by: Yiwen Jiang <jiangyiwen@huawei.com> Suggested-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Hannes Reinicke <hare@suse.de> Reviewed-by: Ewan Milne <emilne@redhat.com> Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-02-04cfq-iosched: Allow parent cgroup to preempt its childJan Kara
Currently we don't allow sync workload of one cgroup to preempt sync workload of any other cgroup. This is because we want to achieve service separation between cgroups. However in cases where cgroup preempting is ancestor of the current cgroup, there is no need of separation and idling introduces unnecessary overhead. This hurts for example the case when workload is isolated within a cgroup but journalling threads are in root cgroup. Simple way to demostrate the issue is using: dbench4 -c /usr/share/dbench4/client.txt -t 10 -D /mnt 1 on ext4 filesystem on plain SATA drive (mounted with barrier=0 to make difference more visible). When all processes are in the root cgroup, reported throughput is 153.132 MB/sec. When dbench process gets its own blkio cgroup, reported throughput drops to 26.1006 MB/sec. Fix the problem by making check in cfq_should_preempt() more benevolent and allow preemption by ancestor cgroup. This improves the throughput reported by dbench4 to 48.9106 MB/sec. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jan Kara <jack@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-04cfq-iosched: Allow sync noidle workloads to preempt each otherJan Kara
The original idea with preemption of sync noidle queues (introduced in commit 718eee0579b8 "cfq-iosched: fairness for sync no-idle queues") was that we service all sync noidle queues together, we don't idle on any of the queues individually and we idle only if there is no sync noidle queue to be served. This intention also matches the original test: if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD && new_cfqq->service_tree == cfqq->service_tree) return true; However since at that time cfqq->service_tree was not set for idling queues, this test was unreliable and was replaced in commit e4a229196a7c "cfq-iosched: fix no-idle preemption logic" by: if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD && cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD && new_cfqq->service_tree->count == 1) return true; That was a reliable test but was actually doing something different - now we preempt sync noidle queue only if the new queue is the only one busy in the service tree. These days cfq queue is kept in service tree even if it is idling and thus the original check would be safe again. But since we actually check that cfq queues are in the same cgroup, of the same priority class and workload type (sync noidle), we know that new_cfqq is fine to preempt cfqq. So just remove the service tree check. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jan Kara <jack@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-04cfq-iosched: Reorder checks in cfq_should_preempt()Jan Kara
Move check for preemption by rt class up. There is no functional change but it makes arguing about conditions simpler since we can be sure both cfq queues are from the same ioprio class. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jan Kara <jack@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-04cfq-iosched: Don't group_idle if cfqq has big thinktimeJan Kara
There is no point in idling on a cfq group if the only cfq queue that is there has too big thinktime. Signed-off-by: Jan Kara <jack@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-01Merge branch 'libnvdimm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm fixes from Dan Williams: "1/ Fixes to the libnvdimm 'pfn' device that establishes a reserved area for storing a struct page array. 2/ Fixes for dax operations on a raw block device to prevent pagecache collisions with dax mappings. 3/ A fix for pfn_t usage in vm_insert_mixed that lead to a null pointer de-reference. These have received build success notification from the kbuild robot across 153 configs and pass the latest ndctl tests" * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: phys_to_pfn_t: use phys_addr_t mm: fix pfn_t to page conversion in vm_insert_mixed block: use DAX for partition table reads block: revert runtime dax control of the raw block device fs, block: force direct-I/O for dax-enabled block devices devm_memremap_pages: fix vmem_altmap lifetime + alignment handling libnvdimm, pfn: fix restoring memmap location libnvdimm: fix mode determination for e820 devices
2016-02-01deadline: remove unused struct memberTahsin Erdogan
commit 63de428b139d3d31d86ebe25ae97b33f6540fb7e ("deadline-iosched: allow non-sequential batching") removed last use of last_sector. Signed-off-by: Tahsin Erdogan <tahsin@google.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-01-30block: use DAX for partition table readsDan Williams
Avoid populating pagecache when the block device is in DAX mode. Otherwise these page cache entries collide with the fsync/msync implementation and break data durability guarantees. Cc: Jan Kara <jack@suse.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Andrew Morton <akpm@linux-foundation.org> Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com> Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-30block: revert runtime dax control of the raw block deviceDan Williams
Dynamically enabling DAX requires that the page cache first be flushed and invalidated. This must occur atomically with the change of DAX mode otherwise we confuse the fsync/msync tracking and violate data durability guarantees. Eliminate the possibilty of DAX-disabled to DAX-enabled transitions for now and revisit this for the next cycle. Cc: Jan Kara <jack@suse.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-29Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block layer fix from Jens Axboe: "This just contains the fix for the split issue that we had in -rc1. It's been well tested at this point, so let's get it in mainline so we don't have the same split issue for -rc2" * 'for-linus' of git://git.kernel.dk/linux-block: block: fix bio splitting on max sectors
2016-01-23Merge tag 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma Pull rdma updates from Doug Ledford: "Initial roundup of 4.5 merge window patches - Remove usage of ib_query_device and instead store attributes in ib_device struct - Move iopoll out of block and into lib, rename to irqpoll, and use in several places in the rdma stack as our new completion queue polling library mechanism. Update the other block drivers that already used iopoll to use the new mechanism too. - Replace the per-entry GID table locks with a single GID table lock - IPoIB multicast cleanup - Cleanups to the IB MR facility - Add support for 64bit extended IB counters - Fix for netlink oops while parsing RDMA nl messages - RoCEv2 support for the core IB code - mlx4 RoCEv2 support - mlx5 RoCEv2 support - Cross Channel support for mlx5 - Timestamp support for mlx5 - Atomic support for mlx5 - Raw QP support for mlx5 - MAINTAINERS update for mlx4/mlx5 - Misc ocrdma, qib, nes, usNIC, cxgb3, cxgb4, mlx4, mlx5 updates - Add support for remote invalidate to the iSER driver (pushed through the RDMA tree due to dependencies, acknowledged by nab) - Update to NFSoRDMA (pushed through the RDMA tree due to dependencies, acknowledged by Bruce)" * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (169 commits) IB/mlx5: Unify CQ create flags check IB/mlx5: Expose Raw Packet QP to user space consumers {IB, net}/mlx5: Move the modify QP operation table to mlx5_ib IB/mlx5: Support setting Ethernet priority for Raw Packet QPs IB/mlx5: Add Raw Packet QP query functionality IB/mlx5: Add create and destroy functionality for Raw Packet QP IB/mlx5: Refactor mlx5_ib_qp to accommodate other QP types IB/mlx5: Allocate a Transport Domain for each ucontext net/mlx5_core: Warn on unsupported events of QP/RQ/SQ net/mlx5_core: Add RQ and SQ event handling net/mlx5_core: Export transport objects IB/mlx5: Expose CQE version to user-space IB/mlx5: Add CQE version 1 support to user QPs and SRQs IB/mlx5: Fix data validation in mlx5_ib_alloc_ucontext IB/sa: Fix netlink local service GFP crash IB/srpt: Remove redundant wc array IB/qib: Improve ipoib UD performance IB/mlx4: Advertise RoCE v2 support IB/mlx4: Create and use another QP1 for RoCEv2 IB/mlx4: Enable send of RoCE QP1 packets with IP/UDP headers ...
2016-01-22block: fix bio splitting on max sectorsMing Lei
After commit e36f62042880(block: split bios to maxpossible length), bio can be splitted in the middle of a vector entry, then it is easy to split out one bio which size isn't aligned with block size, especially when the block size is bigger than 512. This patch fixes the issue by making the max io size aligned to logical block size. Fixes: e36f62042880(block: split bios to maxpossible length) Reported-by: Stefan Haberland <sth@linux.vnet.ibm.com> Cc: Keith Busch <keith.busch@intel.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-01-22wrappers for ->i_mutex accessAl Viro
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-21Merge branch 'for-4.5/nvme' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull NVMe updates from Jens Axboe: "Last branch for this series is the nvme changes. It's in a separate branch to avoid splitting too much between core and NVMe changes, since NVMe is still helping drive some blk-mq changes. That said, not a huge amount of core changes in here. The grunt of the work is the continued split of the code" * 'for-4.5/nvme' of git://git.kernel.dk/linux-block: (67 commits) uapi: update install list after nvme.h rename NVMe: Export NVMe attributes to sysfs group NVMe: Shutdown controller only for power-off NVMe: IO queue deletion re-write NVMe: Remove queue freezing on resets NVMe: Use a retryable error code on reset NVMe: Fix admin queue ring wrap nvme: make SG_IO support optional nvme: fixes for NVME_IOCTL_IO_CMD on the char device nvme: synchronize access to ctrl->namespaces nvme: Move nvme_freeze/unfreeze_queues to nvme core PCI/AER: include header file NVMe: Export namespace attributes to sysfs NVMe: Add pci error handlers block: remove REQ_NO_TIMEOUT flag nvme: merge iod and cmd_info nvme: meta_sg doesn't have to be an array nvme: properly free resources for cancelled command nvme: simplify completion handling nvme: special case AEN requests ...
2016-01-19Merge branch 'for-4.5/core' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block updates from Jens Axboe: "We don't have a lot of core changes this time around, it's mostly in drivers, which will come in a subsequent pull. The cores changes include: - blk-mq - Prep patch from Christoph, changing blk_mq_alloc_request() to take flags instead of just using gfp_t for sleep/nosleep. - Doc patch from me, clarifying the difference between legacy and blk-mq for timer usage. - Fixes from Raghavendra for memory-less numa nodes, and a reuse of CPU masks. - Cleanup from Geliang Tang, using offset_in_page() instead of open coding it. - From Ilya, rename request_queue slab to it reflects what it holds, and a fix for proper use of bdgrab/put. - A real fix for the split across stripe boundaries from Keith. We yanked a broken version of this from 4.4-rc final, this one works. - From Mike Krinkin, emit a trace message when we split. - From Wei Tang, two small cleanups, not explicitly clearing memory that is already cleared" * 'for-4.5/core' of git://git.kernel.dk/linux-block: block: use bd{grab,put}() instead of open-coding block: split bios to max possible length block: add call to split trace point blk-mq: Avoid memoryless numa node encoded in hctx numa_node blk-mq: Reuse hardware context cpumask for tags blk-mq: add a flags parameter to blk_mq_alloc_request Revert "blk-flush: Queue through IO scheduler when flush not required" block: clarify blk_add_timer() use case for blk-mq bio: use offset_in_page macro block: do not initialise statics to 0 or NULL block: do not initialise globals to 0 or NULL block: rename request_queue slab cache
2016-01-13Merge tag 'libnvdimm-for-4.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "The bulk of this has appeared in -next and independently received a build success notification from the kbuild robot. The 'for-4.5/block- dax' topic branch was rebased over the weekend to drop the "block device end-of-life" rework that Al would like to see re-implemented with a notifier, and to address bug reports against the badblocks integration. There is pending feedback against "libnvdimm: Add a poison list and export badblocks" received last week. Linda identified some localized fixups that we will handle incrementally. Summary: - Media error handling: The 'badblocks' implementation that originated in md-raid is up-levelled to a generic capability of a block device. This initial implementation is limited to being consulted in the pmem block-i/o path. Later, 'badblocks' will be consulted when creating dax mappings. - Raw block device dax: For virtualization and other cases that want large contiguous mappings of persistent memory, add the capability to dax-mmap a block device directly. - Increased /dev/mem restrictions: Add an option to treat all io-memory as IORESOURCE_EXCLUSIVE, i.e. disable /dev/mem access while a driver is actively using an address range. This behavior is controlled via the new CONFIG_IO_STRICT_DEVMEM option and can be overridden by the existing "iomem=relaxed" kernel command line option. - Miscellaneous fixes include a 'pfn'-device huge page alignment fix, block device shutdown crash fix, and other small libnvdimm fixes" * tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (32 commits) block: kill disk_{check|set|clear|alloc}_badblocks libnvdimm, pmem: nvdimm_read_bytes() badblocks support pmem, dax: disable dax in the presence of bad blocks pmem: fail io-requests to known bad blocks libnvdimm: convert to statically allocated badblocks libnvdimm: don't fail init for full badblocks list block, badblocks: introduce devm_init_badblocks block: clarify badblocks lifetime badblocks: rename badblocks_free to badblocks_exit libnvdimm, pmem: move definition of nvdimm_namespace_add_poison to nd.h libnvdimm: Add a poison list and export badblocks nfit_test: Enable DSMs for all test NFITs md: convert to use the generic badblocks code block: Add badblock management for gendisks badblocks: Add core badblock management code block: fix del_gendisk() vs blkdev_ioctl crash block: enable dax for raw block devices block: introduce bdev_file_inode() restrict /dev/mem to idle io memory ranges arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug ...
2016-01-12block: split bios to max possible lengthKeith Busch
This splits bio in the middle of a vector to form the largest possible bio at the h/w's desired alignment, and guarantees the bio being split will have some data. The criteria for splitting is changed from the max sectors to the h/w's optimal sector alignment if it is provided. For h/w that advertise their block storage's underlying chunk size, it's a big performance win to not submit commands that cross them. If sector alignment is not provided, this patch uses the max sectors as before. This addresses the performance issue commit d380561113 attempted to fix, but was reverted due to splitting logic error. Signed-off-by: Keith Busch <keith.busch@intel.com> Cc: Jens Axboe <axboe@fb.com> Cc: Ming Lei <tom.leiming@gmail.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: <stable@vger.kernel.org> # 4.4.x- Signed-off-by: Jens Axboe <axboe@fb.com>