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2016-09-17blk-mq: abstract tag allocation out into sbitmap libraryOmar Sandoval
This is a generally useful data structure, so make it available to anyone else who might want to use it. It's also a nice cleanup separating the allocation logic from the rest of the tag handling logic. The code is behind a new Kconfig option, CONFIG_SBITMAP, which is only selected by CONFIG_BLOCK for now. This should be a complete noop functionality-wise. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-16blk-mq: account higher order dispatchJens Axboe
We currently account a '0' dispatch, and anything above that still falls below the range set by BLK_MQ_MAX_DISPATCH_ORDER. If we dispatch more, we don't account it. Change the last bucket to be inclusive of anything above the range we track, and have the sysfs file reflect that by including a '+' in the output: $ cat /sys/block/nvme0n1/mq/0/dispatched 0 1006 1 20229 2 1 4 0 8 0 16 0 32+ 0 Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Omar Sandoval <osandov@fb.com>
2016-09-15blk-mq: kill unused blk_mq_create_mq_map()Jens Axboe
Fixes 1b157939f92a ("blk-mq: get rid of the cpumask in struct blk_mq_tags") Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15blk-mq: get rid of the cpumask in struct blk_mq_tagsChristoph Hellwig
Unused now that NVMe sets up irq affinity before calling into blk-mq. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15blk-mq: provide a default queue mapping for PCI deviceChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15blk-mq: allow the driver to pass in a queue mappingChristoph Hellwig
This allows drivers specify their own queue mapping by overriding the setup-time function that builds the mq_map. This can be used for example to build the map based on the MSI-X vector mapping provided by the core interrupt layer for PCI devices. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15blk-mq: remove ->map_queueChristoph Hellwig
All drivers use the default, so provide an inline version of it. If we ever need other queue mapping we can add an optional method back, although supporting will also require major changes to the queue setup code. This provides better code generation, and better debugability as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15blk-mq: only allocate a single mq_map per tag_setChristoph Hellwig
The mapping is identical for all queues in a tag_set, so stop wasting memory for building multiple. Note that for now I've kept the mq_map pointer in the request_queue, but we'll need to investigate if we can remove it without suffering too much from the additional pointer chasing. The same would apply to the mq_ops pointer as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15blk-mq: don't redistribute hardware queues on a CPU hotplug eventChristoph Hellwig
Currently blk-mq will totally remap hardware context when a CPU hotplug even happened, which causes major havoc for drivers, as they are never told about this remapping. E.g. any carefully sorted out CPU affinity will just be completely messed up. The rebuild also doesn't really help for the common case of cpu hotplug, which is soft onlining / offlining of cpus - in this case we should just leave the queue and irq mapping as is. If it actually worked it would have helped in the case of physical cpu hotplug, although for that we'd need a way to actually notify the driver. Note that drivers may already be able to accommodate such a topology change on their own, e.g. using the reset_controller sysfs file in NVMe will cause the driver to get things right for this case. With the rebuild removed we will simplify retain the queue mapping for a soft offlined CPU that will work when it comes back online, and will map any newly onlined CPU to queue 0 until the driver initiates a rebuild of the queue map. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-14blk-mq: introduce blk_mq_delay_kick_requeue_list()Mike Snitzer
blk_mq_delay_kick_requeue_list() provides the ability to kick the q->requeue_list after a specified time. To do this the request_queue's 'requeue_work' member was changed to a delayed_work. blk_mq_delay_kick_requeue_list() allows DM to defer processing requeued requests while it doesn't make sense to immediately requeue them (e.g. when all paths in a DM multipath have failed). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-14block: remove remnant refs to hardsectLinus Walleij
commit e1defc4ff0cf57aca6c5e3ff99fa503f5943c1f1 "block: Do away with the notion of hardsect_size" removed the notion of "hardware sector size" from the kernel in favor of logical block size, but references remain in comments and documentation. Update the remaining sites mentioning hardsect. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-14block: enable zeroing of io_poll statisticsStephen Bates
Allow the io_poll statistics to be zeroed to make for easier logging of polling event. Signed-off-by: Stephen Bates <sbates@raithlin.com> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-14block: add poll_considered statisticStephen Bates
In order to help determine the effectiveness of polling in a running system it is usful to determine the ratio of how often the poll function is called vs how often the completion is checked. For this reason we add a poll_considered variable and add it to the sysfs entry for io_poll. Signed-off-by: Stephen Bates <sbates@raithlin.com> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-29blk-mq: prefetch request in blk_mq_tag_to_rq()Jens Axboe
When drivers or the core calls this function, they usually dereference the request shortly there after. Prefetch the first cache line. Profiling IO workloads shows that this is the most common cache miss on the block side of things. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-29blk-mq: turn hctx->run_work into a regular work structJens Axboe
We don't need the larger delayed work struct, since we always run it immediately. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-29block: add kblockd_schedule_work_on()Jens Axboe
Add a helper to schedule a regular struct work on a particular CPU. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-24blk-mq: improve warning for running a queue on the wrong CPUJens Axboe
__blk_mq_run_hw_queue() currently warns if we are running the queue on a CPU that isn't set in its mask. However, this can happen if a CPU is being offlined, and the workqueue handling will place the work on CPU0 instead. Improve the warning so that it only triggers if the batch cpu in the hardware queue is currently online. If it triggers for that case, then it's indicative of a flow problem in blk-mq, so we want to retain it for that case. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-24blk-mq: don't overwrite rq->mq_ctxJens Axboe
We do this in a few places, if the CPU is offline. This isn't allowed, though, since on multi queue hardware, we can't just move a request from one software queue to another, if they map to different hardware queues. The request and tag isn't valid on another hardware queue. This can happen if plugging races with CPU offlining. But it does no harm, since it can only happen in the window where we are currently busy freezing the queue and flushing IO, in preparation for redoing the software <-> hardware queue mappings. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-24block: make sure a big bio is split into at most 256 bvecsMing Lei
After arbitrary bio size was introduced, the incoming bio may be very big. We have to split the bio into small bios so that each holds at most BIO_MAX_PAGES bvecs for safety reason, such as bio_clone(). This patch fixes the following kernel crash: > [ 172.660142] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 > [ 172.660229] IP: [<ffffffff811e53b4>] bio_trim+0xf/0x2a > [ 172.660289] PGD 7faf3e067 PUD 7f9279067 PMD 0 > [ 172.660399] Oops: 0000 [#1] SMP > [...] > [ 172.664780] Call Trace: > [ 172.664813] [<ffffffffa007f3be>] ? raid1_make_request+0x2e8/0xad7 [raid1] > [ 172.664846] [<ffffffff811f07da>] ? blk_queue_split+0x377/0x3d4 > [ 172.664880] [<ffffffffa005fb5f>] ? md_make_request+0xf6/0x1e9 [md_mod] > [ 172.664912] [<ffffffff811eb860>] ? generic_make_request+0xb5/0x155 > [ 172.664947] [<ffffffffa0445c89>] ? prio_io+0x85/0x95 [bcache] > [ 172.664981] [<ffffffffa0448252>] ? register_cache_set+0x355/0x8d0 [bcache] > [ 172.665016] [<ffffffffa04497d3>] ? register_bcache+0x1006/0x1174 [bcache] The issue can be reproduced by the following steps: - create one raid1 over two virtio-blk - build bcache device over the above raid1 and another cache device and bucket size is set as 2Mbytes - set cache mode as writeback - run random write over ext4 on the bcache device Fixes: 54efd50(block: make generic_make_request handle arbitrarily sized bios) Reported-by: Sebastian Roesner <sroesner-kernelorg@roesner-online.de> Reported-by: Eric Wheeler <bcache@lists.ewheeler.net> Cc: stable@vger.kernel.org (4.3+) Cc: Shaohua Li <shli@fb.com> Acked-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-16block: Fix race triggered by blk_set_queue_dying()Bart Van Assche
blk_set_queue_dying() can be called while another thread is submitting I/O or changing queue flags, e.g. through dm_stop_queue(). Hence protect the QUEUE_FLAG_DYING flag change with locking. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Mike Snitzer <snitzer@redhat.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-16block: Fix secure eraseAdrian Hunter
Commit 288dab8a35a0 ("block: add a separate operation type for secure erase") split REQ_OP_SECURE_ERASE from REQ_OP_DISCARD without considering all the places REQ_OP_DISCARD was being used to mean either. Fix those. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Fixes: 288dab8a35a0 ("block: add a separate operation type for secure erase") Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-07block: rename bio bi_rw to bi_opfJens Axboe
Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower portion and the op code in the higher portions. This means that old code that relies on manually setting bi_rw is most likely going to be broken. Instead of letting that brokeness linger, rename the member, to force old and out-of-tree code to break at compile time instead of at runtime. No intended functional changes in this commit. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04blk-mq: fix deadlock in blk_mq_register_disk() error pathJens Axboe
If we fail registering any of the hardware queues, we call into blk_mq_unregister_disk() with the hotplug mutex already held. Since blk_mq_unregister_disk() attempts to acquire the same mutex, we end up in a less than happy place. Reported-by: Jinpu Wang <jinpu.wang@profitbricks.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04block: fix bdi vs gendisk lifetime mismatchDan Williams
The name for a bdi of a gendisk is derived from the gendisk's devt. However, since the gendisk is destroyed before the bdi it leaves a window where a new gendisk could dynamically reuse the same devt while a bdi with the same name is still live. Arrange for the bdi to hold a reference against its "owner" disk device while it is registered. Otherwise we can hit sysfs duplicate name collisions like the following: WARNING: CPU: 10 PID: 2078 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x64/0x80 sysfs: cannot create duplicate filename '/devices/virtual/bdi/259:1' Hardware name: HP ProLiant DL580 Gen8, BIOS P79 05/06/2015 0000000000000286 0000000002c04ad5 ffff88006f24f970 ffffffff8134caec ffff88006f24f9c0 0000000000000000 ffff88006f24f9b0 ffffffff8108c351 0000001f0000000c ffff88105d236000 ffff88105d1031e0 ffff8800357427f8 Call Trace: [<ffffffff8134caec>] dump_stack+0x63/0x87 [<ffffffff8108c351>] __warn+0xd1/0xf0 [<ffffffff8108c3cf>] warn_slowpath_fmt+0x5f/0x80 [<ffffffff812a0d34>] sysfs_warn_dup+0x64/0x80 [<ffffffff812a0e1e>] sysfs_create_dir_ns+0x7e/0x90 [<ffffffff8134faaa>] kobject_add_internal+0xaa/0x320 [<ffffffff81358d4e>] ? vsnprintf+0x34e/0x4d0 [<ffffffff8134ff55>] kobject_add+0x75/0xd0 [<ffffffff816e66b2>] ? mutex_lock+0x12/0x2f [<ffffffff8148b0a5>] device_add+0x125/0x610 [<ffffffff8148b788>] device_create_groups_vargs+0xd8/0x100 [<ffffffff8148b7cc>] device_create_vargs+0x1c/0x20 [<ffffffff811b775c>] bdi_register+0x8c/0x180 [<ffffffff811b7877>] bdi_register_dev+0x27/0x30 [<ffffffff813317f5>] add_disk+0x175/0x4a0 Cc: <stable@vger.kernel.org> Reported-by: Yi Zhang <yizhan@redhat.com> Tested-by: Yi Zhang <yizhan@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Fixed up missing 0 return in bdi_register_owner(). Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04blk-mq: Allow timeouts to run while queue is freezingGabriel Krisman Bertazi
In case a submitted request gets stuck for some reason, the block layer can prevent the request starvation by starting the scheduled timeout work. If this stuck request occurs at the same time another thread has started a queue freeze, the blk_mq_timeout_work will not be able to acquire the queue reference and will return silently, thus not issuing the timeout. But since the request is already holding a q_usage_counter reference and is unable to complete, it will never release its reference, preventing the queue from completing the freeze started by first thread. This puts the request_queue in a hung state, forever waiting for the freeze completion. This was observed while running IO to a NVMe device at the same time we toggled the CPU hotplug code. Eventually, once a request got stuck requiring a timeout during a queue freeze, we saw the CPU Hotplug notification code get stuck inside blk_mq_freeze_queue_wait, as shown in the trace below. [c000000deaf13690] [c000000deaf13738] 0xc000000deaf13738 (unreliable) [c000000deaf13860] [c000000000015ce8] __switch_to+0x1f8/0x350 [c000000deaf138b0] [c000000000ade0e4] __schedule+0x314/0x990 [c000000deaf13940] [c000000000ade7a8] schedule+0x48/0xc0 [c000000deaf13970] [c0000000005492a4] blk_mq_freeze_queue_wait+0x74/0x110 [c000000deaf139e0] [c00000000054b6a8] blk_mq_queue_reinit_notify+0x1a8/0x2e0 [c000000deaf13a40] [c0000000000e7878] notifier_call_chain+0x98/0x100 [c000000deaf13a90] [c0000000000b8e08] cpu_notify_nofail+0x48/0xa0 [c000000deaf13ac0] [c0000000000b92f0] _cpu_down+0x2a0/0x400 [c000000deaf13b90] [c0000000000b94a8] cpu_down+0x58/0xa0 [c000000deaf13bc0] [c0000000006d5dcc] cpu_subsys_offline+0x2c/0x50 [c000000deaf13bf0] [c0000000006cd244] device_offline+0x104/0x140 [c000000deaf13c30] [c0000000006cd40c] online_store+0x6c/0xc0 [c000000deaf13c80] [c0000000006c8c78] dev_attr_store+0x68/0xa0 [c000000deaf13cc0] [c0000000003974d0] sysfs_kf_write+0x80/0xb0 [c000000deaf13d00] [c0000000003963e8] kernfs_fop_write+0x188/0x200 [c000000deaf13d50] [c0000000002e0f6c] __vfs_write+0x6c/0xe0 [c000000deaf13d90] [c0000000002e1ca0] vfs_write+0xc0/0x230 [c000000deaf13de0] [c0000000002e2cdc] SyS_write+0x6c/0x110 [c000000deaf13e30] [c000000000009204] system_call+0x38/0xb4 The fix is to allow the timeout work to execute in the window between dropping the initial refcount reference and the release of the last reference, which actually marks the freeze completion. This can be achieved with percpu_refcount_tryget, which does not require the counter to be alive. This way the timeout work can do it's job and terminate a stuck request even during a freeze, returning its reference and avoiding the deadlock. Allowing the timeout to run is just a part of the fix, since for some devices, we might get stuck again inside the device driver's timeout handler, should it attempt to allocate a new request in that path - which is a quite common action for Abort commands, which need to be sent after a timeout. In NVMe, for instance, we call blk_mq_alloc_request from inside the timeout handler, which will fail during a freeze, since it also tries to acquire a queue reference. I considered a similar change to blk_mq_alloc_request as a generic solution for further device driver hangs, but we can't do that, since it would allow new requests to disturb the freeze process. I thought about creating a new function in the block layer to support unfreezable requests for these occasions, but after working on it for a while, I feel like this should be handled in a per-driver basis. I'm now experimenting with changes to the NVMe timeout path, but I'm open to suggestions of ways to make this generic. Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com> Cc: Brian King <brking@linux.vnet.ibm.com> Cc: Keith Busch <keith.busch@intel.com> Cc: linux-nvme@lists.infradead.org Cc: linux-block@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04block: fix use-after-free in seq fileVegard Nossum
I got a KASAN report of use-after-free: ================================================================== BUG: KASAN: use-after-free in klist_iter_exit+0x61/0x70 at addr ffff8800b6581508 Read of size 8 by task trinity-c1/315 ============================================================================= BUG kmalloc-32 (Not tainted): kasan: bad access detected ----------------------------------------------------------------------------- Disabling lock debugging due to kernel taint INFO: Allocated in disk_seqf_start+0x66/0x110 age=144 cpu=1 pid=315 ___slab_alloc+0x4f1/0x520 __slab_alloc.isra.58+0x56/0x80 kmem_cache_alloc_trace+0x260/0x2a0 disk_seqf_start+0x66/0x110 traverse+0x176/0x860 seq_read+0x7e3/0x11a0 proc_reg_read+0xbc/0x180 do_loop_readv_writev+0x134/0x210 do_readv_writev+0x565/0x660 vfs_readv+0x67/0xa0 do_preadv+0x126/0x170 SyS_preadv+0xc/0x10 do_syscall_64+0x1a1/0x460 return_from_SYSCALL_64+0x0/0x6a INFO: Freed in disk_seqf_stop+0x42/0x50 age=160 cpu=1 pid=315 __slab_free+0x17a/0x2c0 kfree+0x20a/0x220 disk_seqf_stop+0x42/0x50 traverse+0x3b5/0x860 seq_read+0x7e3/0x11a0 proc_reg_read+0xbc/0x180 do_loop_readv_writev+0x134/0x210 do_readv_writev+0x565/0x660 vfs_readv+0x67/0xa0 do_preadv+0x126/0x170 SyS_preadv+0xc/0x10 do_syscall_64+0x1a1/0x460 return_from_SYSCALL_64+0x0/0x6a CPU: 1 PID: 315 Comm: trinity-c1 Tainted: G B 4.7.0+ #62 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 ffffea0002d96000 ffff880119b9f918 ffffffff81d6ce81 ffff88011a804480 ffff8800b6581500 ffff880119b9f948 ffffffff8146c7bd ffff88011a804480 ffffea0002d96000 ffff8800b6581500 fffffffffffffff4 ffff880119b9f970 Call Trace: [<ffffffff81d6ce81>] dump_stack+0x65/0x84 [<ffffffff8146c7bd>] print_trailer+0x10d/0x1a0 [<ffffffff814704ff>] object_err+0x2f/0x40 [<ffffffff814754d1>] kasan_report_error+0x221/0x520 [<ffffffff8147590e>] __asan_report_load8_noabort+0x3e/0x40 [<ffffffff83888161>] klist_iter_exit+0x61/0x70 [<ffffffff82404389>] class_dev_iter_exit+0x9/0x10 [<ffffffff81d2e8ea>] disk_seqf_stop+0x3a/0x50 [<ffffffff8151f812>] seq_read+0x4b2/0x11a0 [<ffffffff815f8fdc>] proc_reg_read+0xbc/0x180 [<ffffffff814b24e4>] do_loop_readv_writev+0x134/0x210 [<ffffffff814b4c45>] do_readv_writev+0x565/0x660 [<ffffffff814b8a17>] vfs_readv+0x67/0xa0 [<ffffffff814b8de6>] do_preadv+0x126/0x170 [<ffffffff814b92ec>] SyS_preadv+0xc/0x10 This problem can occur in the following situation: open() - pread() - .seq_start() - iter = kmalloc() // succeeds - seqf->private = iter - .seq_stop() - kfree(seqf->private) - pread() - .seq_start() - iter = kmalloc() // fails - .seq_stop() - class_dev_iter_exit(seqf->private) // boom! old pointer As the comment in disk_seqf_stop() says, stop is called even if start failed, so we need to reinitialise the private pointer to NULL when seq iteration stops. An alternative would be to set the private pointer to NULL when the kmalloc() in disk_seqf_start() fails. Cc: stable@vger.kernel.org Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04block: add missing group association in bio-cloning functionsPaolo Valente
When a bio is cloned, the newly created bio must be associated with the same blkcg as the original bio (if BLK_CGROUP is enabled). If this operation is not performed, then the new bio is not associated with any group, and the group of the current task is returned when the group of the bio is requested. Depending on the cloning frequency, this may cause a large percentage of the bios belonging to a given group to be treated as if belonging to other groups (in most cases as if belonging to the root group). The expected group isolation may thereby be broken. This commit adds the missing association in bio-cloning functions. Fixes: da2f0f74cf7d ("Btrfs: add support for blkio controllers") Cc: stable@vger.kernel.org # v4.3+ Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Reviewed-by: Nikolay Borisov <kernel@kyup.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04blkcg: kill unused field nr_undestroyed_grpsHou Tao
'nr_undestroyed_grps' in struct throtl_data was used to count the number of throtl_grp related with throtl_data, but now throtl_grp is tracked by blkcg_gq, so it is useless anymore. Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04block: remove BLK_DEV_DAX config optionRoss Zwisler
The functionality for block device DAX was already removed with commit acc93d30d7d4 ("Revert "block: enable dax for raw block devices"") However, we still had a config option hanging around that was always disabled because it depended on CONFIG_BROKEN. This config option was introduced in commit 03cdadb04077 ("block: disable block device DAX by default") This change reverts that commit, removing the dead config option. Link: http://lkml.kernel.org/r/20160729182314.6368-1-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block driver updates from Jens Axboe: "This branch also contains core changes. I've come to the conclusion that from 4.9 and forward, I'll be doing just a single branch. We often have dependencies between core and drivers, and it's hard to always split them up appropriately without pulling core into drivers when that happens. That said, this contains: - separate secure erase type for the core block layer, from Christoph. - set of discard fixes, from Christoph. - bio shrinking fixes from Christoph, as a followup up to the op/flags change in the core branch. - map and append request fixes from Christoph. - NVMeF (NVMe over Fabrics) code from Christoph. This is pretty exciting! - nvme-loop fixes from Arnd. - removal of ->driverfs_dev from Dan, after providing a device_add_disk() helper. - bcache fixes from Bhaktipriya and Yijing. - cdrom subchannel read fix from Vchannaiah. - set of lightnvm updates from Wenwei, Matias, Johannes, and Javier. - set of drbd updates and fixes from Fabian, Lars, and Philipp. - mg_disk error path fix from Bart. - user notification for failed device add for loop, from Minfei. - NVMe in general: + NVMe delay quirk from Guilherme. + SR-IOV support and command retry limits from Keith. + fix for memory-less NUMA node from Masayoshi. + use UINT_MAX for discard sectors, from Minfei. + cancel IO fixes from Ming. + don't allocate unused major, from Neil. + error code fixup from Dan. + use constants for PSDT/FUSE from James. + variable init fix from Jay. + fabrics fixes from Ming, Sagi, and Wei. + various fixes" * 'for-4.8/drivers' of git://git.kernel.dk/linux-block: (115 commits) nvme/pci: Provide SR-IOV support nvme: initialize variable before logical OR'ing it block: unexport various bio mapping helpers scsi/osd: open code blk_make_request target: stop using blk_make_request block: simplify and export blk_rq_append_bio block: ensure bios return from blk_get_request are properly initialized virtio_blk: use blk_rq_map_kern memstick: don't allow REQ_TYPE_BLOCK_PC requests block: shrink bio size again block: simplify and cleanup bvec pool handling block: get rid of bio_rw and READA block: don't ignore -EOPNOTSUPP blkdev_issue_write_same block: introduce BLKDEV_DISCARD_ZERO to fix zeroout NVMe: don't allocate unused nvme_major nvme: avoid crashes when node 0 is memoryless node. nvme: Limit command retries loop: Make user notify for adding loop device failed nvme-loop: fix nvme-loop Kconfig dependencies nvmet: fix return value check in nvmet_subsys_alloc() ...
2016-07-26Merge branch 'for-4.8/core' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block updates from Jens Axboe: - the big change is the cleanup from Mike Christie, cleaning up our uses of command types and modified flags. This is what will throw some merge conflicts - regression fix for the above for btrfs, from Vincent - following up to the above, better packing of struct request from Christoph - a 2038 fix for blktrace from Arnd - a few trivial/spelling fixes from Bart Van Assche - a front merge check fix from Damien, which could cause issues on SMR drives - Atari partition fix from Gabriel - convert cfq to highres timers, since jiffies isn't granular enough for some devices these days. From Jan and Jeff - CFQ priority boost fix idle classes, from me - cleanup series from Ming, improving our bio/bvec iteration - a direct issue fix for blk-mq from Omar - fix for plug merging not involving the IO scheduler, like we do for other types of merges. From Tahsin - expose DAX type internally and through sysfs. From Toshi and Yigal * 'for-4.8/core' of git://git.kernel.dk/linux-block: (76 commits) block: Fix front merge check block: do not merge requests without consulting with io scheduler block: Fix spelling in a source code comment block: expose QUEUE_FLAG_DAX in sysfs block: add QUEUE_FLAG_DAX for devices to advertise their DAX support Btrfs: fix comparison in __btrfs_map_block() block: atari: Return early for unsupported sector size Doc: block: Fix a typo in queue-sysfs.txt cfq-iosched: Charge at least 1 jiffie instead of 1 ns cfq-iosched: Fix regression in bonnie++ rewrite performance cfq-iosched: Convert slice_resid from u64 to s64 block: Convert fifo_time from ulong to u64 blktrace: avoid using timespec block/blk-cgroup.c: Declare local symbols static block/bio-integrity.c: Add #include "blk.h" block/partition-generic.c: Remove a set-but-not-used variable block: bio: kill BIO_MAX_SIZE cfq-iosched: temporarily boost queue priority for idle classes block: drbd: avoid to use BIO_MAX_SIZE block: bio: remove BIO_MAX_SECTORS ...
2016-07-25Merge branch 'timers-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "This update provides the following changes: - The rework of the timer wheel which addresses the shortcomings of the current wheel (cascading, slow search for next expiring timer, etc). That's the first major change of the wheel in almost 20 years since Finn implemted it. - A large overhaul of the clocksource drivers init functions to consolidate the Device Tree initialization - Some more Y2038 updates - A capability fix for timerfd - Yet another clock chip driver - The usual pile of updates, comment improvements all over the place" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (130 commits) tick/nohz: Optimize nohz idle enter clockevents: Make clockevents_subsys static clocksource/drivers/time-armada-370-xp: Fix return value check timers: Implement optimization for same expiry time in mod_timer() timers: Split out index calculation timers: Only wake softirq if necessary timers: Forward the wheel clock whenever possible timers/nohz: Remove pointless tick_nohz_kick_tick() function timers: Optimize collect_expired_timers() for NOHZ timers: Move __run_timers() function timers: Remove set_timer_slack() leftovers timers: Switch to a non-cascading wheel timers: Reduce the CPU index space to 256k timers: Give a few structs and members proper names hlist: Add hlist_is_singular_node() helper signals: Use hrtimer for sigtimedwait() timers: Remove the deprecated mod_timer_pinned() API timers, net/ipv4/inet: Initialize connection request timers as pinned timers, drivers/tty/mips_ejtag: Initialize the poll timer as pinned timers, drivers/tty/metag_da: Initialize the poll timer as pinned ...
2016-07-20block: Fix front merge checkDamien Le Moal
For a front merge, the maximum number of sectors of the request must be checked against the front merge BIO sector, not the current sector of the request. Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20block: do not merge requests without consulting with io schedulerTahsin Erdogan
Before merging a bio into an existing request, io scheduler is called to get its approval first. However, the requests that come from a plug flush may get merged by block layer without consulting with io scheduler. In case of CFQ, this can cause fairness problems. For instance, if a request gets merged into a low weight cgroup's request, high weight cgroup now will depend on low weight cgroup to get scheduled. If high weigt cgroup needs that io request to complete before submitting more requests, then it will also lose its timeslice. Following script demonstrates the problem. Group g1 has a low weight, g2 and g3 have equal high weights but g2's requests are adjacent to g1's requests so they are subject to merging. Due to these merges, g2 gets poor disk time allocation. cat > cfq-merge-repro.sh << "EOF" #!/bin/bash set -e IO_ROOT=/mnt-cgroup/io mkdir -p $IO_ROOT if ! mount | grep -qw $IO_ROOT; then mount -t cgroup none -oblkio $IO_ROOT fi cd $IO_ROOT for i in g1 g2 g3; do if [ -d $i ]; then rmdir $i fi done mkdir g1 && echo 10 > g1/blkio.weight mkdir g2 && echo 495 > g2/blkio.weight mkdir g3 && echo 495 > g3/blkio.weight RUNTIME=10 (echo $BASHPID > g1/cgroup.procs && fio --readonly --name name1 --filename /dev/sdb \ --rw read --size 64k --bs 64k --time_based \ --runtime=$RUNTIME --offset=0k &> /dev/null)& (echo $BASHPID > g2/cgroup.procs && fio --readonly --name name1 --filename /dev/sdb \ --rw read --size 64k --bs 64k --time_based \ --runtime=$RUNTIME --offset=64k &> /dev/null)& (echo $BASHPID > g3/cgroup.procs && fio --readonly --name name1 --filename /dev/sdb \ --rw read --size 64k --bs 64k --time_based \ --runtime=$RUNTIME --offset=256k &> /dev/null)& sleep $((RUNTIME+1)) for i in g1 g2 g3; do echo ---- $i ---- cat $i/blkio.time done EOF # ./cfq-merge-repro.sh ---- g1 ---- 8:16 162 ---- g2 ---- 8:16 165 ---- g3 ---- 8:16 686 After applying the patch: # ./cfq-merge-repro.sh ---- g1 ---- 8:16 90 ---- g2 ---- 8:16 445 ---- g3 ---- 8:16 471 Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20block: Fix spelling in a source code commentBart Van Assche
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20block: expose QUEUE_FLAG_DAX in sysfsYigal Korman
Provides the ability to identify DAX enabled devices in userspace. Signed-off-by: Yigal Korman <yigal@plexistor.com> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20block: unexport various bio mapping helpersChristoph Hellwig
They are unused and potential new users really should use the blk_rq_map* versions. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20scsi/osd: open code blk_make_requestChristoph Hellwig
I wish the OSD code could simply use blk_rq_map_* helpers like everyone else, but the complex nature of deciding if we have DATA IN and/or DATA OUT buffers might make this impossible (at least for a mere human like me). But using blk_rq_append_bio at least allows sharing the setup code between request with or without dat a buffers, and given that this is the last user of blk_make_request it allows getting rid of that somewhat awkward interface. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Boaz Harrosh <ooo@electrozaur.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20block: simplify and export blk_rq_append_bioChristoph Hellwig
The target SCSI passthrough backend is much better served with the low-level blk_rq_append_bio construct then the helpers built on top of it, so export it. Also use the opportunity to remove the pointless request_queue argument and make the code flow a little more readable. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20block: ensure bios return from blk_get_request are properly initializedChristoph Hellwig
blk_get_request is used for BLOCK_PC and similar passthrough requests. Currently we always need to call blk_rq_set_block_pc or an open coded version of it to allow appending bios using the request mapping helpers later on, which is a somewhat awkward API. Instead move the initialization part of blk_rq_set_block_pc into blk_get_request, so that we always have a safe to use request. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20block: simplify and cleanup bvec pool handlingChristoph Hellwig
Instead of a flag and an index just make sure an index of 0 means no need to free the bvec array. Also move the constants related to the bvec pools together and use a consistent naming scheme for them. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20block: don't ignore -EOPNOTSUPP blkdev_issue_write_sameChristoph Hellwig
WRITE SAME is a data integrity operation and we can't simply ignore errors. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20block: introduce BLKDEV_DISCARD_ZERO to fix zerooutChristoph Hellwig
Currently blkdev_issue_zeroout cascades down from discards (if the driver guarantees that discards zero data), to WRITE SAME and then to a loop writing zeroes. Unfortunately we ignore run-time EOPNOTSUPP errors in the block layer blkdev_issue_discard helper to work around DM volumes that may have mixed discard support underneath. This patch intoroduces a new BLKDEV_DISCARD_ZERO flag to blkdev_issue_discard that indicates we are called for zeroing operation. This allows both to ignore the EOPNOTSUPP hack and actually consolidating the discard_zeroes_data check into the function. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-13block: atari: Return early for unsupported sector sizeGabriel Krisman Bertazi
For 4K LBA or very large disks, atari_partition can easily get tricked into thinking it has found an Atari partition table. Depending on the data in the disk, it ends up creating partitions with awkward lengths. We saw logs like this while playing with fio. [5.625867] nvme2n1: AHDI p2 [5.625872] nvme2n1: p2 size 2910030523 extends beyond EOD, truncated People has had issues with misinterpreted AHDI partition tables for a long time, see this BSD thread from 1995, for example. https://mail-index.netbsd.org/port-atari/1995/11/19/0001.html Since the atari partition, according to the spec, doesn't even support sector sizes with more than 512, a quick sanity check is reasonable to just bail out early, before even attempting to read sector 0. Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-08Merge branch 'for-4.8/block' of ↵Jens Axboe
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm into for-4.8/drivers Dan writes: "The removal of ->driverfs_dev in favor of just passing the parent device in as a parameter to add_disk(). See below, it has received a "Reviewed-by" from Christoph, Bart, and Johannes. It is also a pre-requisite for Fam Zheng's work to cleanup gendisk uevents vs attribute visibility [1]. We would extend device_add_disk() to take an attribute_group list. This is based off a branch of block.git/for-4.8/drivers and has received a positive build success notification from the kbuild robot across several configs. [1]: "gendisk: Generate uevent after attribute available" http://marc.info/?l=linux-virtualization&m=146725201522201&w=2"
2016-07-08blk-mq: Introduce blk_mq_reinit_tagsetSagi Grimberg
The new nvme-rdma driver will need to reinitialize all the tags as part of the error recovery procedure (realloc the tag memory region). Add a helper in blk-mq for it that can iterate over all requests in a tagset to make this easier. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Tested-by: Ming Lin <ming.l@ssi.samsung.com> Reviewed-by: Stephen Bates <Stephen.Bates@pmcs.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Steve Wise <swise@opengridcomputing.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-07timers: Remove set_timer_slack() leftoversThomas Gleixner
We now have implicit batching in the timer wheel. The slack API is no longer used, so remove it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Andrew F. Davis <afd@ti.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Chris Mason <clm@fb.com> Cc: David S. Miller <davem@davemloft.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: George Spelvin <linux@sciencehorizons.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jaehoon Chung <jh80.chung@samsung.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: John Stultz <john.stultz@linaro.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathias Nyman <mathias.nyman@intel.com> Cc: Pali Rohár <pali.rohar@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Sebastian Reichel <sre@kernel.org> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: linux-block@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mmc@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-usb@vger.kernel.org Cc: netdev@vger.kernel.org Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160704094342.189813118@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-05block: Export blk_pollSagi Grimberg
The new NVMe over fabrics target will make use of this outside from a module. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-05blk-mq: add blk_mq_alloc_request_hctxMing Lin
For some protocols like NVMe over Fabrics we need to be able to send initialization commands to a specific queue. Based on an earlier patch from Christoph Hellwig <hch@lst.de>. Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> [hch: disallow sleeping allocation, req_op fixes] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-01block: fix use-after-free in sys_ioprio_get()Omar Sandoval
get_task_ioprio() accesses the task->io_context without holding the task lock and thus can race with exit_io_context(), leading to a use-after-free. The reproducer below hits this within a few seconds on my 4-core QEMU VM: #define _GNU_SOURCE #include <assert.h> #include <unistd.h> #include <sys/syscall.h> #include <sys/wait.h> int main(int argc, char **argv) { pid_t pid, child; long nproc, i; /* ioprio_set(IOPRIO_WHO_PROCESS, 0, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0)); */ syscall(SYS_ioprio_set, 1, 0, 0x6000); nproc = sysconf(_SC_NPROCESSORS_ONLN); for (i = 0; i < nproc; i++) { pid = fork(); assert(pid != -1); if (pid == 0) { for (;;) { pid = fork(); assert(pid != -1); if (pid == 0) { _exit(0); } else { child = wait(NULL); assert(child == pid); } } } pid = fork(); assert(pid != -1); if (pid == 0) { for (;;) { /* ioprio_get(IOPRIO_WHO_PGRP, 0); */ syscall(SYS_ioprio_get, 2, 0); } } } for (;;) { /* ioprio_get(IOPRIO_WHO_PGRP, 0); */ syscall(SYS_ioprio_get, 2, 0); } return 0; } This gets us KASAN dumps like this: [ 35.526914] ================================================================== [ 35.530009] BUG: KASAN: out-of-bounds in get_task_ioprio+0x7b/0x90 at addr ffff880066f34e6c [ 35.530009] Read of size 2 by task ioprio-gpf/363 [ 35.530009] ============================================================================= [ 35.530009] BUG blkdev_ioc (Not tainted): kasan: bad access detected [ 35.530009] ----------------------------------------------------------------------------- [ 35.530009] Disabling lock debugging due to kernel taint [ 35.530009] INFO: Allocated in create_task_io_context+0x2b/0x370 age=0 cpu=0 pid=360 [ 35.530009] ___slab_alloc+0x55d/0x5a0 [ 35.530009] __slab_alloc.isra.20+0x2b/0x40 [ 35.530009] kmem_cache_alloc_node+0x84/0x200 [ 35.530009] create_task_io_context+0x2b/0x370 [ 35.530009] get_task_io_context+0x92/0xb0 [ 35.530009] copy_process.part.8+0x5029/0x5660 [ 35.530009] _do_fork+0x155/0x7e0 [ 35.530009] SyS_clone+0x19/0x20 [ 35.530009] do_syscall_64+0x195/0x3a0 [ 35.530009] return_from_SYSCALL_64+0x0/0x6a [ 35.530009] INFO: Freed in put_io_context+0xe7/0x120 age=0 cpu=0 pid=1060 [ 35.530009] __slab_free+0x27b/0x3d0 [ 35.530009] kmem_cache_free+0x1fb/0x220 [ 35.530009] put_io_context+0xe7/0x120 [ 35.530009] put_io_context_active+0x238/0x380 [ 35.530009] exit_io_context+0x66/0x80 [ 35.530009] do_exit+0x158e/0x2b90 [ 35.530009] do_group_exit+0xe5/0x2b0 [ 35.530009] SyS_exit_group+0x1d/0x20 [ 35.530009] entry_SYSCALL_64_fastpath+0x1a/0xa4 [ 35.530009] INFO: Slab 0xffffea00019bcd00 objects=20 used=4 fp=0xffff880066f34ff0 flags=0x1fffe0000004080 [ 35.530009] INFO: Object 0xffff880066f34e58 @offset=3672 fp=0x0000000000000001 [ 35.530009] ================================================================== Fix it by grabbing the task lock while we poke at the io_context. Cc: stable@vger.kernel.org Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>