summaryrefslogtreecommitdiffstats
path: root/drivers/block
Commit message (Collapse)AuthorAgeFilesLines
* nbd: zero from and len fields in NBD_CMD_DISCONNECT.Hani Benhabiles2014-06-061-5/+2
| | | | | | | | | | | | Len field is already set to zero, but not the from field which is sent as 0xfffffffffffffe00. This makes no sense, and may cause confuse server implementations doing sanity checks (qemu-nbd is an example.) Signed-off-by: Hani Benhabiles <hani@linux.com> Cc: Paul Clements <paul.clements@us.sios.com> Cc: Paul Clements <Paul.Clements@steeleye.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'akpm' (patchbomb from Andrew) into nextLinus Torvalds2014-06-042-5/+15
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc updates from Andrew Morton: - a few fixes for 3.16. Cc'ed to stable so they'll get there somehow. - various misc fixes and cleanups - most of the ocfs2 queue. Review is slow... - most of MM. The MM queue is pretty huge this time, but not much in the way of feature work. - some tweaks under kernel/ - printk maintenance work - updates to lib/ - checkpatch updates - tweaks to init/ * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (276 commits) fs/autofs4/dev-ioctl.c: add __init to autofs_dev_ioctl_init fs/ncpfs/getopt.c: replace simple_strtoul by kstrtoul init/main.c: remove an ifdef kthreads: kill CLONE_KERNEL, change kernel_thread(kernel_init) to avoid CLONE_SIGHAND init/main.c: add initcall_blacklist kernel parameter init/main.c: don't use pr_debug() fs/binfmt_flat.c: make old_reloc() static fs/binfmt_elf.c: fix bool assignements fs/efs: convert printk(KERN_DEBUG to pr_debug fs/efs: add pr_fmt / use __func__ fs/efs: convert printk to pr_foo() scripts/checkpatch.pl: device_initcall is not the only __initcall substitute checkpatch: check stable email address checkpatch: warn on unnecessary void function return statements checkpatch: prefer kstrto<foo> to sscanf(buf, "%<lhuidx>", &bar); checkpatch: add warning for kmalloc/kzalloc with multiply checkpatch: warn on #defines ending in semicolon checkpatch: make --strict a default for files in drivers/net and net/ checkpatch: always warn on missing blank line after variable declaration block checkpatch: fix wildcard DT compatible string checking ...
| * zram: correct offset usage in zram_bio_discardWeijie Yang2014-06-041-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want to skip the physical block(PAGE_SIZE) which is partially covered by the discard bio, so we check the remaining size and subtract it if there is a need to goto the next physical block. The current offset usage in zram_bio_discard is incorrect, it will cause its upper filesystem breakdown. Consider the following scenario: On some architecture or config, PAGE_SIZE is 64K for example, filesystem is set up on zram disk without PAGE_SIZE aligned, a discard bio leads to a offset = 4K and size=72K, normally, it should not really discard any physical block as it partially cover two physical blocks. However, with the current offset usage, it will discard the second physical block and free its memory, which will cause filesystem breakdown. This patch corrects the offset usage in zram_bio_discard. Signed-off-by: Weijie Yang <weijie.yang@samsung.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Bob Liu <bob.liu@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * brd: return -ENOSPC rather than -ENOMEM on page allocation failureMatthew Wilcox2014-06-041-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | brd is effectively a thinly provisioned device. Thinly provisioned devices return -ENOSPC when they can't write a new block. -ENOMEM is an implementation detail that callers shouldn't know. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Acked-by: Dave Chinner <david@fromorbit.com> Cc: Dheeraj Reddy <dheeraj.reddy@intel.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * brd: add support for rw_page()Matthew Wilcox2014-06-041-0/+10
| | | | | | | | | | | | | | | | | | Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Dheeraj Reddy <dheeraj.reddy@intel.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | blk-mq: let blk_mq_tag_to_rq() take blk_mq_tags as the main parameterJens Axboe2014-06-041-1/+3
|/ | | | | | | | | | We currently pass in the hardware queue, and get the tags from there. But from scsi-mq, with a shared tag space, it's a lot more convenient to pass in the blk_mq_tags instead as the hardware queue isn't always directly available. So instead of having to re-map to a given hardware queue from rq->mq_ctx, just pass in the tags structure. Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2014-06-033-3/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next Pull scheduler updates from Ingo Molnar: "The main scheduling related changes in this cycle were: - various sched/numa updates, for better performance - tree wide cleanup of open coded nice levels - nohz fix related to rq->nr_running use - cpuidle changes and continued consolidation to improve the kernel/sched/idle.c high level idle scheduling logic. As part of this effort I pulled cpuidle driver changes from Rafael as well. - standardized idle polling amongst architectures - continued work on preparing better power/energy aware scheduling - sched/rt updates - misc fixlets and cleanups" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (49 commits) sched/numa: Decay ->wakee_flips instead of zeroing sched/numa: Update migrate_improves/degrades_locality() sched/numa: Allow task switch if load imbalance improves sched/rt: Fix 'struct sched_dl_entity' and dl_task_time() comments, to match the current upstream code sched: Consolidate open coded implementations of nice level frobbing into nice_to_rlimit() and rlimit_to_nice() sched: Initialize rq->age_stamp on processor start sched, nohz: Change rq->nr_running to always use wrappers sched: Fix the rq->next_balance logic in rebalance_domains() and idle_balance() sched: Use clamp() and clamp_val() to make sys_nice() more readable sched: Do not zero sg->cpumask and sg->sgp->power in build_sched_groups() sched/numa: Fix initialization of sched_domain_topology for NUMA sched: Call select_idle_sibling() when not affine_sd sched: Simplify return logic in sched_read_attr() sched: Simplify return logic in sched_copy_attr() sched: Fix exec_start/task_hot on migrated tasks arm64: Remove TIF_POLLING_NRFLAG metag: Remove TIF_POLLING_NRFLAG sched/idle: Make cpuidle_idle_call() void sched/idle: Reflow cpuidle_idle_call() sched/idle: Delay clearing the polling bit ...
| * Merge tag 'v3.15-rc6' into sched/core, to pick up the latest fixesIngo Molnar2014-05-221-4/+7
| |\ | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * \ Merge branch 'sched/urgent' into sched/core, to avoid conflictsIngo Molnar2014-05-0717-481/+1388
| |\ \ | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | sched, treewide: Replace hardcoded nice values with MIN_NICE/MAX_NICEDongsheng Yang2014-04-183-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace various -20/+19 hardcoded nice values with MIN_NICE/MAX_NICE. Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/ff13819fd09b7a5dba5ab5ae797f2e7019bdfa17.1394532288.git.yangds.fnst@cn.fujitsu.com Cc: devel@driverdev.osuosl.org Cc: devicetree@vger.kernel.org Cc: fcoe-devel@open-fcoe.org Cc: linux390@de.ibm.com Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-s390@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: nbd-general@lists.sourceforge.net Cc: ocfs2-devel@oss.oracle.com Cc: openipmi-developer@lists.sourceforge.net Cc: qla2xxx-upstream@qlogic.com Cc: linux-arch@vger.kernel.org [ Consolidated the patches, twiddled the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | Merge branch 'for-3.16/drivers' of git://git.kernel.dk/linux-block into nextLinus Torvalds2014-06-0223-1148/+1212
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block driver changes from Jens Axboe: "Now that the core bits are in, here's the pull request for the driver related changes for 3.16. Nothing out of the ordinary here, mostly business as usual. There are a few pulls of for-3.16/core into this branch, which were done when the blk-mq was modified after the mtip32xx conversion was put in. The pull request contains: - skd and cciss converted to use pci_enable_msix_exact(). From Alexander Gordeev. - A few mtip32xx fixes from Asai @ Micron. - The conversion of mtip32xx from make_request_fn to blk-mq, and a later small fix for that conversion on quiescing for non-queued IO. From me. - A fix for bsg to use an exported function to check whether this driver is request based or not. Needed updating for blk-mq, which is request based, but does not have a request_fn hook. From me. - Small floppy bug fix from Jiri. - A series of cleanups for the cdrom uniform layer from Joe Perches. Gets rid of various old ugly macros, making the code conform more to the modern coding style. - A series of patches for drbd from the drbd crew (Lars Ellenberg and Philipp Reisner). - A use-after-free fix for null_blk from Ming Lei. - Also from Ming Lei is a performance patch for virtio-blk, which can net us a 3x win on kvm platforms where world notification is expensive. - Ming Lei also fixed a stall issue in virtio-blk, due to a race between queue start/stop and resource limits. - A small batch of fixes for xen-blk{back,front} from Olaf Hering and Valentin Priescu" * 'for-3.16/drivers' of git://git.kernel.dk/linux-block: (54 commits) block: virtio_blk: don't hold spin lock during world switch xen-blkback: defer freeing blkif to avoid blocking xenwatch xen blkif.h: fix comment typo in discard-alignment xen/blkback: disable discard feature if requested by toolstack xen-blkfront: remove type check from blkfront_setup_discard floppy: do not corrupt bio.bi_flags when reading block 0 mtip32xx: move error handling to service thread virtio_blk: fix race between start and stop queue mtip32xx: stop block hardware queues before quiescing IO mtip32xx: blk_mq_init_queue() returns an ERR_PTR mtip32xx: convert to use blk-mq cdrom: Remove unnecessary prototype for cdrom_get_disc_info cdrom: Remove unnecessary prototype for cdrom_mrw_exit cdrom: Remove cdrom_count_tracks prototype cdrom: Remove cdrom_get_next_writeable prototype cdrom: Remove cdrom_get_last_written prototype cdrom: Move mmc_ioctls above cdrom_ioctl to remove unnecessary prototype cdrom: Remove unnecessary sanitize_format prototype cdrom: Remove unnecessary check_for_audio_disc prototype cdrom: Remove prototype for open_for_data ...
| * | | | block: virtio_blk: don't hold spin lock during world switchMing Lei2014-05-301-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Firstly, it isn't necessary to hold lock of vblk->vq_lock when notifying hypervisor about queued I/O. Secondly, virtqueue_notify() will cause world switch and it may take long time on some hypervisors(such as, qemu-arm), so it isn't good to hold the lock and block other vCPUs. On arm64 quad core VM(qemu-kvm), the patch can increase I/O performance a lot with VIRTIO_RING_F_EVENT_IDX enabled: - without the patch: 14K IOPS - with the patch: 34K IOPS fio script: [global] direct=1 bsrange=4k-4k timeout=10 numjobs=4 ioengine=libaio iodepth=64 filename=/dev/vdc group_reporting=1 [f1] rw=randread Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: virtualization@lists.linux-foundation.org Signed-off-by: Ming Lei <ming.lei@canonical.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org # 3.13+ Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | Merge branch 'for-3.16/core' into for-3.16/driversJens Axboe2014-05-301-3/+1
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pulled in for the blk_mq_tag_to_rq() change, which impacts mtip32xx. Signed-off-by: Jens Axboe <axboe@fb.com>
| * \ \ \ \ Merge branch 'stable/for-jens-3.16' of ↵Jens Axboe2014-05-283-41/+56
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip into for-3.16/drivers Konrad writes: Please git pull the following branch: git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git stable/for-jens-3.16 which has a bunch of fixes to the Xen block frontend and backend driver and a new parameter for Xen backend driver - an override (set by the toolstack) whether to expose the discard support (if disk of course supports it) or not.
| | * | | | | xen-blkback: defer freeing blkif to avoid blocking xenwatchValentin Priescu2014-05-282-14/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently xenwatch blocks in VBD disconnect, waiting for all pending I/O requests to finish. If the VBD is attached to a hot-swappable disk, then xenwatch can hang for a long period of time, stalling other watches. INFO: task xenwatch:39 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. ffff880057f01bd0 0000000000000246 ffff880057f01ac0 ffffffff810b0782 ffff880057f01ad0 00000000000131c0 0000000000000004 ffff880057edb040 ffff8800344c6080 0000000000000000 ffff880058c00ba0 ffff880057edb040 Call Trace: [<ffffffff810b0782>] ? irq_to_desc+0x12/0x20 [<ffffffff8128f761>] ? list_del+0x11/0x40 [<ffffffff8147a080>] ? wait_for_common+0x60/0x160 [<ffffffff8147bcef>] ? _raw_spin_lock_irqsave+0x2f/0x50 [<ffffffff8147bd49>] ? _raw_spin_unlock_irqrestore+0x19/0x20 [<ffffffff8147a26a>] schedule+0x3a/0x60 [<ffffffffa018fe6a>] xen_blkif_disconnect+0x8a/0x100 [xen_blkback] [<ffffffff81079f70>] ? wake_up_bit+0x40/0x40 [<ffffffffa018ffce>] xen_blkbk_remove+0xae/0x1e0 [xen_blkback] [<ffffffff8130b254>] xenbus_dev_remove+0x44/0x90 [<ffffffff81345cb7>] __device_release_driver+0x77/0xd0 [<ffffffff81346488>] device_release_driver+0x28/0x40 [<ffffffff813456e8>] bus_remove_device+0x78/0xe0 [<ffffffff81342c9f>] device_del+0x12f/0x1a0 [<ffffffff81342d2d>] device_unregister+0x1d/0x60 [<ffffffffa0190826>] frontend_changed+0xa6/0x4d0 [xen_blkback] [<ffffffffa019c252>] ? frontend_changed+0x192/0x650 [xen_netback] [<ffffffff8130ae50>] ? cmp_dev+0x60/0x60 [<ffffffff81344fe4>] ? bus_for_each_dev+0x94/0xa0 [<ffffffff8130b06e>] xenbus_otherend_changed+0xbe/0x120 [<ffffffff8130b4cb>] frontend_changed+0xb/0x10 [<ffffffff81309c82>] xenwatch_thread+0xf2/0x130 [<ffffffff81079f70>] ? wake_up_bit+0x40/0x40 [<ffffffff81309b90>] ? xenbus_directory+0x80/0x80 [<ffffffff810799d6>] kthread+0x96/0xa0 [<ffffffff81485934>] kernel_thread_helper+0x4/0x10 [<ffffffff814839f3>] ? int_ret_from_sys_call+0x7/0x1b [<ffffffff8147c17c>] ? retint_restore_args+0x5/0x6 [<ffffffff81485930>] ? gs_change+0x13/0x13 With this patch, when there is still pending I/O, the actual disconnect is done by the last reference holder (last pending I/O request). In this case, xenwatch doesn't block indefinitely. Signed-off-by: Valentin Priescu <priescuv@amazon.com> Reviewed-by: Steven Kady <stevkady@amazon.com> Reviewed-by: Steven Noonan <snoonan@amazon.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| | * | | | | xen/blkback: disable discard feature if requested by toolstackOlaf Hering2014-05-281-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Newer toolstacks may provide a boolean property "discard-enable" in the backend node. Its purpose is to disable discard for file backed storage to avoid fragmentation. Recognize this setting also for physical storage. If that property exists and is false, do not advertise "feature-discard" to the frontend. Signed-off-by: Olaf Hering <olaf@aepfle.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| | * | | | | xen-blkfront: remove type check from blkfront_setup_discardOlaf Hering2014-05-281-26/+14
| | | |_|/ / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In its initial implementation a check for "type" was added, but only phy and file are handled. This breaks advertised discard support for other type values such as qdisk. Fix and simplify this function: If the backend advertises discard support it is supposed to implement it properly, so enable feature_discard unconditionally. If the backend advertises the need for a certain granularity and alignment then propagate both properties to the blocklayer. The discard-secure property is a boolean, update the code to reflect that. Signed-off-by: Olaf Hering <olaf@aepfle.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | | | | Merge branch 'for-3.16/core' into for-3.16/driversJens Axboe2014-05-283-31/+1
| |\ \ \ \ \ | | | |/ / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | Pull in core changes (again), since we got rid of the alloc/free hctx mq_ops hooks and mtip32xx then needed updating again. Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | Merge branch 'for-3.16/core' into for-3.16/driversJens Axboe2014-05-283-35/+6
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mtip32xx uses blk_mq_alloc_reserved_request(), so pull in the core changes so we have a properly merged end result. Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | floppy: do not corrupt bio.bi_flags when reading block 0Jiri Kosina2014-05-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 41a55b4de39 ("floppy: silence warning during disk test") caused bio.bi_flags being overwritten, and its initialization to BIO_UPTODATE in bio_init() to be lost. This was unnoticed until 7b7b68bba5 ("floppy: bail out in open() if drive is not responding to block0 read"), because the error value wasn't checked for in the bio completion callback. Now we are actually looking at the error, and the loss of BIO_UPTODATE causes EIO to be wrongly passed to the callback, which confuses the FD_OPEN_SHOULD_FAIL_BIT logic. Fix this by not destroying previous value of bi_flags when setting BIO_QUIET. Cc: Stephen Hemminger <shemminger@vyatta.com> Reported-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
| * | | | | | mtip32xx: move error handling to service threadAsai Thambi S P2014-05-202-26/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move error handling to service thread, and use mtip_set_timeout() to set timeouts for HDIO_DRIVE_TASK and HDIO_DRIVE_CMD IOCTL commands. Signed-off-by: Selvan Mani <smani@micron.com> Signed-off-by: Asai Thambi S P <asamymuthupa@micron.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | virtio_blk: fix race between start and stop queueMing Lei2014-05-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When there isn't enough vring descriptor for adding to vq, blk-mq will be put as stopped state until some of pending descriptors are completed & freed. Unfortunately, the vq's interrupt may come just before blk-mq's BLK_MQ_S_STOPPED flag is set, so the blk-mq will still be kept as stopped even though lots of descriptors are completed and freed in the interrupt handler. The worst case is that all pending descriptors are freed in the interrupt handler, and the queue is kept as stopped forever. This patch fixes the problem by starting/stopping blk-mq with holding vq_lock. Cc: Jens Axboe <axboe@kernel.dk> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | mtip32xx: stop block hardware queues before quiescing IOJens Axboe2014-05-141-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need to stop the block layer queues to prevent new "normal" IO from entering the driver, while we wait for existing commands to finish. Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | mtip32xx: blk_mq_init_queue() returns an ERR_PTRDan Carpenter2014-05-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We changed this from blk_alloc_queue_node() to blk_mq_init_queue() so the check needs to be updated as well. Fixes: ffc771b3ca8b2 ('mtip32xx: convert to use blk-mq') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | mtip32xx: convert to use blk-mqJens Axboe2014-05-132-616/+297
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This rips out timeout handling, requeueing, etc in converting it to use blk-mq instead. Acked-by: Asai Thambi S P <asamymuthupa@micron.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | block: null_blk: fix use after freeMing Lei2014-05-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | entry(cmd->ll_list) may belong to new request once end_cmd() returns, so fix the bug with the patch. Without the change, it is easy to observe oops when doing null_blk(timer) test. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: use list_first_entry_or_null in first_peer_device/first_connectionLars Ellenberg2014-04-301-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If there are no peer_devices or connections, I'd rather have NULL than some "arbitrary" address pretending to point to a struct. Helps to avoid hard to debug symptoms, in case we ever try to use and dereference a drbd_connection or drbd_peer_device where we in fact don't have any connection at all. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: Allow attaching of a newly created device to any backing devicePhilipp Reisner2014-04-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A newly created device was never exposed before, i.e. has a exposed_data_uuid of 0. Then it is valid to attach to any current_uuid of a backing device (of course also to a newly created one (4)) Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: Test cstate while holding req_lockPhilipp Reisner2014-04-301-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case a connection transitions into C_TIMEOUT within the timer function (request_timer_fn()) we need to make sure that the receiver thread (potentially running on a different CPU) sees the updated cstate later on. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: use blk_set_stacking_limits()Philipp Reisner2014-04-301-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ...instead directly assigning to q->limits.discard_zeroes_data Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: evaluate disk and network timeout on different requestsLars Ellenberg2014-04-301-14/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just because it is the oldest not yet completed request does not make it the oldest request waiting for disk. Or waiting for the peer. And we completely missed already completed requests that would still hold references to activity log extents, waiting only for the barrier ack. Find two oldest not yet completely processed requests, one that is still waiting for local completion, and one that is still waiting for some response from the peer. These may or may not be the same request object. Then separately apply the network and disk timeouts, respectively. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: Fix a hole in the challange-response connection authenticationPhilipp Reisner2014-04-301-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the implementation as it was, the two peers sent each other a challenge, and expects the challenge hashed with the shared secret back. A attacker could simply wait for the challenge of the peer, and send the same challenge back. Then it waits for the response, and sends the same response back. Prevent this by not accepting a challenge from the peer that is the same as the challenge sent to the peer. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: always implicitly close last epoch when idleLars Ellenberg2014-04-301-33/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Once our sender thread needs to wait_for_work(), and actually needs to schedule(), just before we do that, we already check if it is useful to implicitly close the last epoch. The condition was too strict: only implicitly close the epoch, if there have been no new (write) requests at all. The assumption was that if there were new requests, they would always be communicated one way or another, and would send necessary epoch separating barriers explicitly. This is not always true, e.g. when becoming diskless, or while explicitly starting a full resync. The last communicated epoch could stay open for a long time, locking down corresponding activity log extents. It is safe to always implicitly send that last barrier, as soon as we determin that there cannot be more requests in the last communicated epoch, even if there have been (uncommunicated) new requests in new epochs meanwhile. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: add back some fairness to AL transactionsLars Ellenberg2014-04-303-2/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When batching more updates to the activity log into single transactions, we lost the ability for new requests to force themselves into the active set: all preparation steps became non-blocking, and if all currently hot extents keep busy, they could starve out new incoming requests to cold extents for quite a while. This can only happen if your IO backend accepts more IO operations per average DRBD replication round trip time than you have al-extents configured. If we have incoming requests to cold extents, at least do one blocking update per transaction. In an artificial worst-case workload on SSD with an asynchronous 600 ms replication link, with al-extents = 7 (the minimum we allow), and concurrent full resynch, without this patch, some write requests have been observed to be starved for 40 seconds. With this patch, application observed a worst case latency of twice the replication round trip time. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: keep max-bio size during detach/attach on disconnected primaryLars Ellenberg2014-04-301-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want to store in persistent meta data what the peer DRBD can handle, which, due to spreading requests to multiple bios, may be more than its backing device can handle. Otherwise, if a disconnected Primary temporarily loses access to its local data as well, we may accidentally shrink the max-bio setting, portentially causing already assembled, but not yet processed, application bios to be spuriously failed due to device limits. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: fix a race between start_resync and send_and_submitLars Ellenberg2014-04-301-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the drbd make request function, specifically in drbd_send_and_submit(), we decide whether we want to send the actual write request, or only a "set this block out of sync" information. We do so based on the current connection state, while holding the req_lock. The connection state is not supposed to change while holding the req_lock. But in drbd_start_resync, we did change that state anyways, while only holding the global_state_lock, which is enough to change sync-after dependencies (paused vs active resync), but not good enough to change the connection state. Fix: in drbd_start_resync, first grab the req_lock to serialize with drbd_send_and_submit(), before grabbing the global_state_lock to be able to evaluate the sync-after dependencies. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: Enable QUEUE_FLAG_DISCARD only if the peer can recieve P_TRIMLars Ellenberg2014-04-304-4/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow the user of REQ_DISCARD. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: prepare sending side for REQ_DISCARDLars Ellenberg2014-04-304-4/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Note that I do NOT call __drbd_chk_io_error for failed REQ_DISCARD. That may be wrong, though, or needs to differ between EOPNOTSUPP and other errors... Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: prepare receiving side for REQ_DISCARDLars Ellenberg2014-04-305-26/+100
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the receiver needs to serve a discard request on a queue that does not announce to be discard cabable, it falls back to do synchronous blkdev_issue_zeroout(). We expect only "reasonably" large (up to one activity log extent?) discard requests. We do this to not to not block the receiver for too long in this fallback code path, and to not set/clear too many bits inside one spinlock_irq_save() in drbd_set_in_sync/drbd_set_out_of_sync, Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: allow parallel promote/demote actionsLars Ellenberg2014-04-303-14/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We plan to use genl_family->parallel_ops = true in the future, but need to review all possible interactions first. For now, only selectively drop genl_lock() in drbd_set_role(), instead serializing on our own internal resource->conf_update mutex. We now can be promoted/demoted on many resources in parallel, which may significantly improve cluster failover times when fencing is required. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: perpare for genetlink parallel_opsLars Ellenberg2014-04-303-175/+198
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because all administrative requests via genetlink have been globally serialized via genl_lock(), we used to have one static struct drbd_config_context "admin context". Move this on-stack to the respective callback functions. This will allow us to selectively drop the genl_lock() (or use genl_family->parallel_ops) in the future. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: Do not BUG() when connection breaks in a special wayPhilipp Reisner2014-04-301-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a 'cluster wide' disconnect executes, the result comes back from the peer, and immediately after that the connection breaks then _conn_rq_cond() reported back SS_CW_SUCCESS. Therefore _conn_request_state() calls conn_set_state(), which has a BUG() in it. The BUG() is hit because conn_is_valid_transition() does not like the transaction. Which goes back to is_valid_soft_transition() returning SS_OUTDATE_WO_CONN. This fix is to consider an error reported by is_valid_soft_transition() even when the peer agreed to the transaction. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: don't let application IO pre-empt resync too oftenLars Ellenberg2014-04-303-29/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before, application IO could pre-empt resync activity for up to hardcoded 20 seconds per resync request. A very busy server could throttle the effective resync bandwidth down to one request per 20 seconds. Now, we only let application IO pre-empt resync traffic while the current resync rate estimate is above c-min-rate. If you disable the c-min-rate throttle feature (set c-min-rate = 0), application IO will no longer pre-empt resync traffic at all. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: fix potential distributed deadlock during verify or resyncLars Ellenberg2014-04-302-15/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If max-buffers and socket buffer sizes are "too small" for the chosen resync rate, this could lead potentially lead to a distributed deadlock, which may or may not resolve itself via the "ko-count" and request timeout mechanism, or could be resolved by forced disconnect. One option to deal with this is proper configuration: use larger max-buffer and socket buffers settings, or reduce the resync rate. But even with bad configuration we should not deadlock, but "gracefully" recover. The issue is avoided by using only up to max-buffers/2 for resync requests, and by using max-buffers not as a hard limit for data buffer allocations, but as a throttle threshold only. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: resync: fix too large bursts for very slow ratesLars Ellenberg2014-04-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While merging adjacent dirty blocks into resync requests, the resync rate throttle was disregarded. For very low resync rates, the effective rate may have exceeded the intended rate by a larger margin. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: fix stalled resync detection in /proc/drbdLars Ellenberg2014-04-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we don't make resync or verify progress for "too long", we want to flag it as "stalled". Since 2010, "use rolling marks for resync speed calculation" this "too long" was wrong by a factor of HZ. With HZ 250, it would have been flagged as stalled after 100 minutes. Hardcode 3 minutes instead. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: Allow online layout change of AL while peer is not connectedPhilipp Reisner2014-04-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a user forces the operation he takes the blame in case the peer does not have enough space. No reason to dey this... Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: Remove drbd_wrappers.hPhilipp Reisner2014-04-306-58/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: Leave IO suspended if the fence handler find the peer primaryPhilipp Reisner2014-04-302-11/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Actually we are clearing the susp_fen flag if we are not going to call a fencing handler. For setting the susp_fen flag needs to be edge-triggerd, and not level triggered. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | | | | | drbd: Break a deadlock while concurrent fencing and establishing a connectionPhilipp Reisner2014-04-301-10/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we need to outdate the peer while being promoted to primary, and the connection gets established at the same time, we deadlock in drbd_try_outdate_peer() when trying to clear the susp_fen bit. Fix this by setting the STATE_SENT bit while holding the mutex. Using drbd_change_state(.. , CS_HARD, ..) which does not block until STATE_SENT is cleared, is only for clearness. It does not contribute anything to the fix. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
OpenPOWER on IntegriCloud