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Commit Graph

115 Commits

Author SHA1 Message Date
Ming Lei
86ff7c2a80 blk-mq: introduce BLK_STS_DEV_RESOURCE
This status is returned from driver to block layer if device related
resource is unavailable, but driver can guarantee that IO dispatch
will be triggered in future when the resource is available.

Convert some drivers to return BLK_STS_DEV_RESOURCE.  Also, if driver
returns BLK_STS_RESOURCE and SCHED_RESTART is set, rerun queue after
a delay (BLK_MQ_DELAY_QUEUE) to avoid IO stalls.  BLK_MQ_DELAY_QUEUE is
3 ms because both scsi-mq and nvmefc are using that magic value.

If a driver can make sure there is in-flight IO, it is safe to return
BLK_STS_DEV_RESOURCE because:

1) If all in-flight IOs complete before examining SCHED_RESTART in
blk_mq_dispatch_rq_list(), SCHED_RESTART must be cleared, so queue
is run immediately in this case by blk_mq_dispatch_rq_list();

2) if there is any in-flight IO after/when examining SCHED_RESTART
in blk_mq_dispatch_rq_list():
- if SCHED_RESTART isn't set, queue is run immediately as handled in 1)
- otherwise, this request will be dispatched after any in-flight IO is
  completed via blk_mq_sched_restart()

3) if SCHED_RESTART is set concurently in context because of
BLK_STS_RESOURCE, blk_mq_delay_run_hw_queue() will cover the above two
cases and make sure IO hang can be avoided.

One invariant is that queue will be rerun if SCHED_RESTART is set.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-30 20:18:28 -07:00
Linus Torvalds
0a4b6e2f80 Merge branch 'for-4.16/block' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
 "This is the main pull request for block IO related changes for the
  4.16 kernel. Nothing major in this pull request, but a good amount of
  improvements and fixes all over the map. This contains:

   - BFQ improvements, fixes, and cleanups from Angelo, Chiara, and
     Paolo.

   - Support for SMR zones for deadline and mq-deadline from Damien and
     Christoph.

   - Set of fixes for bcache by way of Michael Lyle, including fixes
     from himself, Kent, Rui, Tang, and Coly.

   - Series from Matias for lightnvm with fixes from Hans Holmberg,
     Javier, and Matias. Mostly centered around pblk, and the removing
     rrpc 1.2 in preparation for supporting 2.0.

   - A couple of NVMe pull requests from Christoph. Nothing major in
     here, just fixes and cleanups, and support for command tracing from
     Johannes.

   - Support for blk-throttle for tracking reads and writes separately.
     From Joseph Qi. A few cleanups/fixes also for blk-throttle from
     Weiping.

   - Series from Mike Snitzer that enables dm to register its queue more
     logically, something that's alwways been problematic on dm since
     it's a stacked device.

   - Series from Ming cleaning up some of the bio accessor use, in
     preparation for supporting multipage bvecs.

   - Various fixes from Ming closing up holes around queue mapping and
     quiescing.

   - BSD partition fix from Richard Narron, fixing a problem where we
     can't mount newer (10/11) FreeBSD partitions.

   - Series from Tejun reworking blk-mq timeout handling. The previous
     scheme relied on atomic bits, but it had races where we would think
     a request had timed out if it to reused at the wrong time.

   - null_blk now supports faking timeouts, to enable us to better
     exercise and test that functionality separately. From me.

   - Kill the separate atomic poll bit in the request struct. After
     this, we don't use the atomic bits on blk-mq anymore at all. From
     me.

   - sgl_alloc/free helpers from Bart.

   - Heavily contended tag case scalability improvement from me.

   - Various little fixes and cleanups from Arnd, Bart, Corentin,
     Douglas, Eryu, Goldwyn, and myself"

* 'for-4.16/block' of git://git.kernel.dk/linux-block: (186 commits)
  block: remove smart1,2.h
  nvme: add tracepoint for nvme_complete_rq
  nvme: add tracepoint for nvme_setup_cmd
  nvme-pci: introduce RECONNECTING state to mark initializing procedure
  nvme-rdma: remove redundant boolean for inline_data
  nvme: don't free uuid pointer before printing it
  nvme-pci: Suspend queues after deleting them
  bsg: use pr_debug instead of hand crafted macros
  blk-mq-debugfs: don't allow write on attributes with seq_operations set
  nvme-pci: Fix queue double allocations
  block: Set BIO_TRACE_COMPLETION on new bio during split
  blk-throttle: use queue_is_rq_based
  block: Remove kblockd_schedule_delayed_work{,_on}()
  blk-mq: Avoid that blk_mq_delay_run_hw_queue() introduces unintended delays
  blk-mq: Rename blk_mq_request_direct_issue() into blk_mq_request_issue_directly()
  lib/scatterlist: Fix chaining support in sgl_alloc_order()
  blk-throttle: track read and write request individually
  block: add bdev_read_only() checks to common helpers
  block: fail op_is_write() requests to read-only partitions
  blk-throttle: export io_serviced_recursive, io_service_bytes_recursive
  ...
2018-01-29 11:51:49 -08:00
Arnd Bergmann
33f782c49a null_blk: remove explicit 'select FAULT_INJECTION'
Selecting FAULT_INJECTION causes a Kconfig warning when CONFIG_DEBUG_KERNEL
is not set:

warning: (BLK_DEV_NULL_BLK && DRM_I915_SELFTEST) selects FAULT_INJECTION which has unmet direct dependencies (DEBUG_KERNEL)

The other drivers that use FAULT_INJECTION tend to have a separate
Kconfig symbol for turning on that feature, so let's do the same
thing here. This may add a bit more complexity than we like, but
it avoids the warning and is more consistent with the rest of the
kernel.

Fixes: 93b570464c ("null_blk: add option for managing IO timeouts")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-11 07:58:31 -07:00
Jens Axboe
93b570464c null_blk: add option for managing IO timeouts
Use the fault injection framework to provide a way for null_blk
to configure timeouts. This only works for queue_mode 1 and 2,
since the bio mode doesn't have code for tracking timeouts.

Let's say you want to have a 10% chance of timing out every
100,000 requests, and for 5 total timeouts, you could do:

modprobe null_blk timeout="100000,10,0,5"

This is useful for adding blktests to test that IO timeouts
are handled appropriately.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-10 09:06:23 -07:00
Jens Axboe
5448aca41c null_blk: wire up timeouts
This is needed to ensure that we actually handle timeouts.
Without it, the queue_mode=1 path will never call blk_add_timer(),
and the queue_mode=2 path will continually just return
EH_RESET_TIMER and we never actually complete the offending request.

This was used to test the new timeout code, and the changes around
killing off REQ_ATOM_COMPLETE.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-09 14:59:19 -07:00
Matias Bjørling
74ede5af27 null_blk: remove lightnvm support
With rrpc to be removed, the null_blk lightnvm support is no longer
functional. Remove the lightnvm implementation and maybe add it to
another module in the future if someone takes on the challenge.

Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-05 08:50:12 -07:00
Jens Axboe
0864fe09ab null_blk: unalign call_single_data
Commit 966a967116 randomly added alignment to this structure, but
it's actually detrimental to performance of null_blk. Test case:

Running on both the home and remote node shows a ~5% degradation
in performance.

While in there, move blk_status_t to the hole after the integer tag
in the nullb_cmd structure. After this patch, we shrink the size
from 192 to 152 bytes.

Fixes: 966a967116 ("smp: Avoid using two cache lines for struct call_single_data")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-12-20 13:16:33 -07:00
David Disseldorp
1addb798e9 null_blk: fix dev->badblocks leak
null_alloc_dev() allocates memory for dev->badblocks, but cleanup
currently only occurs in the configfs release codepath, missing a number
of other places.

This bug was found running the blktests block/010 test, alongside
kmemleak:
rapido1:/blktests# ./check block/010
...
rapido1:/blktests# echo scan > /sys/kernel/debug/kmemleak
[  306.966708] kmemleak: 32 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
rapido1:/blktests# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff88001f86d000 (size 4096):
  comm "modprobe", pid 231, jiffies 4294892415 (age 318.252s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff814b0379>] kmemleak_alloc+0x49/0xa0
    [<ffffffff810f180f>] kmem_cache_alloc+0x9f/0xe0
    [<ffffffff8124e45f>] badblocks_init+0x2f/0x60
    [<ffffffffa0019fae>] 0xffffffffa0019fae
    [<ffffffffa0021273>] nullb_device_badblocks_store+0x63/0x130 [null_blk]
    [<ffffffff810004cd>] do_one_initcall+0x3d/0x170
    [<ffffffff8109fe0d>] do_init_module+0x56/0x1e9
    [<ffffffff8109ebd7>] load_module+0x1c47/0x26a0
    [<ffffffff8109f819>] SyS_finit_module+0xa9/0xd0
    [<ffffffff814b4f60>] entry_SYSCALL_64_fastpath+0x13/0x94

Fixes: 2f54a613c9 ("nullb: badbblocks support")
Reviewed-by: Shaohua Li <shli@fb.com>
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-22 08:43:11 -07:00
Linus Torvalds
e2c5923c34 Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-block
Pull core block layer updates from Jens Axboe:
 "This is the main pull request for block storage for 4.15-rc1.

  Nothing out of the ordinary in here, and no API changes or anything
  like that. Just various new features for drivers, core changes, etc.
  In particular, this pull request contains:

   - A patch series from Bart, closing the whole on blk/scsi-mq queue
     quescing.

   - A series from Christoph, building towards hidden gendisks (for
     multipath) and ability to move bio chains around.

   - NVMe
        - Support for native multipath for NVMe (Christoph).
        - Userspace notifications for AENs (Keith).
        - Command side-effects support (Keith).
        - SGL support (Chaitanya Kulkarni)
        - FC fixes and improvements (James Smart)
        - Lots of fixes and tweaks (Various)

   - bcache
        - New maintainer (Michael Lyle)
        - Writeback control improvements (Michael)
        - Various fixes (Coly, Elena, Eric, Liang, et al)

   - lightnvm updates, mostly centered around the pblk interface
     (Javier, Hans, and Rakesh).

   - Removal of unused bio/bvec kmap atomic interfaces (me, Christoph)

   - Writeback series that fix the much discussed hundreds of millions
     of sync-all units. This goes all the way, as discussed previously
     (me).

   - Fix for missing wakeup on writeback timer adjustments (Yafang
     Shao).

   - Fix laptop mode on blk-mq (me).

   - {mq,name} tupple lookup for IO schedulers, allowing us to have
     alias names. This means you can use 'deadline' on both !mq and on
     mq (where it's called mq-deadline). (me).

   - blktrace race fix, oopsing on sg load (me).

   - blk-mq optimizations (me).

   - Obscure waitqueue race fix for kyber (Omar).

   - NBD fixes (Josef).

   - Disable writeback throttling by default on bfq, like we do on cfq
     (Luca Miccio).

   - Series from Ming that enable us to treat flush requests on blk-mq
     like any other request. This is a really nice cleanup.

   - Series from Ming that improves merging on blk-mq with schedulers,
     getting us closer to flipping the switch on scsi-mq again.

   - BFQ updates (Paolo).

   - blk-mq atomic flags memory ordering fixes (Peter Z).

   - Loop cgroup support (Shaohua).

   - Lots of minor fixes from lots of different folks, both for core and
     driver code"

* 'for-4.15/block' of git://git.kernel.dk/linux-block: (294 commits)
  nvme: fix visibility of "uuid" ns attribute
  blk-mq: fixup some comment typos and lengths
  ide: ide-atapi: fix compile error with defining macro DEBUG
  blk-mq: improve tag waiting setup for non-shared tags
  brd: remove unused brd_mutex
  blk-mq: only run the hardware queue if IO is pending
  block: avoid null pointer dereference on null disk
  fs: guard_bio_eod() needs to consider partitions
  xtensa/simdisk: fix compile error
  nvme: expose subsys attribute to sysfs
  nvme: create 'slaves' and 'holders' entries for hidden controllers
  block: create 'slaves' and 'holders' entries for hidden gendisks
  nvme: also expose the namespace identification sysfs files for mpath nodes
  nvme: implement multipath access to nvme subsystems
  nvme: track shared namespaces
  nvme: introduce a nvme_ns_ids structure
  nvme: track subsystems
  block, nvme: Introduce blk_mq_req_flags_t
  block, scsi: Make SCSI quiesce and resume work reliably
  block: Add the QUEUE_FLAG_PREEMPT_ONLY request queue flag
  ...
2017-11-14 15:32:19 -08:00
Bhumika Goyal
e1919dff15 nullb: make config_item_type const
Make these structures const as they are either passed to the functions
having the argument as const or stored as a reference in the "ci_type"
const field of a config_item structure.

Done using Coccienlle.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-19 16:15:19 +02:00
Wei Yongjun
30c516d750 nullb: fix error return code in null_init()
Fix to return error code -ENOMEM from the null_alloc_dev() error
handling case instead of 0, as done elsewhere in this function.

Fixes: 2984c8684f ("nullb: factor disk parameters")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-17 08:25:06 -06:00
weiping zhang
b3cffc3877 null_blk: add "no_sched" module parameter
add an option that disable io scheduler for null block device.

Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-30 02:07:34 -06:00
Linus Torvalds
a0725ab0c7 Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:
 "This is the first pull request for 4.14, containing most of the code
  changes. It's a quiet series this round, which I think we needed after
  the churn of the last few series. This contains:

   - Fix for a registration race in loop, from Anton Volkov.

   - Overflow complaint fix from Arnd for DAC960.

   - Series of drbd changes from the usual suspects.

   - Conversion of the stec/skd driver to blk-mq. From Bart.

   - A few BFQ improvements/fixes from Paolo.

   - CFQ improvement from Ritesh, allowing idling for group idle.

   - A few fixes found by Dan's smatch, courtesy of Dan.

   - A warning fixup for a race between changing the IO scheduler and
     device remova. From David Jeffery.

   - A few nbd fixes from Josef.

   - Support for cgroup info in blktrace, from Shaohua.

   - Also from Shaohua, new features in the null_blk driver to allow it
     to actually hold data, among other things.

   - Various corner cases and error handling fixes from Weiping Zhang.

   - Improvements to the IO stats tracking for blk-mq from me. Can
     drastically improve performance for fast devices and/or big
     machines.

   - Series from Christoph removing bi_bdev as being needed for IO
     submission, in preparation for nvme multipathing code.

   - Series from Bart, including various cleanups and fixes for switch
     fall through case complaints"

* 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits)
  kernfs: checking for IS_ERR() instead of NULL
  drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set
  drbd: Fix allyesconfig build, fix recent commit
  drbd: switch from kmalloc() to kmalloc_array()
  drbd: abort drbd_start_resync if there is no connection
  drbd: move global variables to drbd namespace and make some static
  drbd: rename "usermode_helper" to "drbd_usermode_helper"
  drbd: fix race between handshake and admin disconnect/down
  drbd: fix potential deadlock when trying to detach during handshake
  drbd: A single dot should be put into a sequence.
  drbd: fix rmmod cleanup, remove _all_ debugfs entries
  drbd: Use setup_timer() instead of init_timer() to simplify the code.
  drbd: fix potential get_ldev/put_ldev refcount imbalance during attach
  drbd: new disk-option disable-write-same
  drbd: Fix resource role for newly created resources in events2
  drbd: mark symbols static where possible
  drbd: Send P_NEG_ACK upon write error in protocol != C
  drbd: add explicit plugging when submitting batches
  drbd: change list_for_each_safe to while(list_first_entry_or_null)
  drbd: introduce drbd_recv_header_maybe_unplug
  ...
2017-09-07 11:59:42 -07:00
Ying Huang
966a967116 smp: Avoid using two cache lines for struct call_single_data
struct call_single_data is used in IPIs to transfer information between
CPUs.  Its size is bigger than sizeof(unsigned long) and less than
cache line size.  Currently it is not allocated with any explicit alignment
requirements.  This makes it possible for allocated call_single_data to
cross two cache lines, which results in double the number of the cache lines
that need to be transferred among CPUs.

This can be fixed by requiring call_single_data to be aligned with the
size of call_single_data. Currently the size of call_single_data is the
power of 2.  If we add new fields to call_single_data, we may need to
add padding to make sure the size of new definition is the power of 2
as well.

Fortunately, this is enforced by GCC, which will report bad sizes.

To set alignment requirements of call_single_data to the size of
call_single_data, a struct definition and a typedef is used.

To test the effect of the patch, I used the vm-scalability multiple
thread swap test case (swap-w-seq-mt).  The test will create multiple
threads and each thread will eat memory until all RAM and part of swap
is used, so that huge number of IPIs are triggered when unmapping
memory.  In the test, the throughput of memory writing improves ~5%
compared with misaligned call_single_data, because of faster IPIs.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Huang, Ying <ying.huang@intel.com>
[ Add call_single_data_t and align with size of call_single_data. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/87bmnqd6lz.fsf@yhuang-mobile.sh.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-29 15:14:38 +02:00
Jens Axboe
b3c3051220 null_blk: use available 'dev' in nullb_device_power_store()
We already have this pointer, no need to use to_nullb_device()
again.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-28 15:06:31 -06:00
Shaohua Li
060fd198a3 block/nullb: delete unnecessary memory free
Commit 2984c86(nullb: factor disk parameters) has a typo. The
nullb_device allocation/free is done outside of null_add_dev. The commit
accidentally frees the nullb_device in error code path.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-28 15:06:17 -06:00
Shaohua Li
0d06a42f79 block/nullb: fix NULL dereference
Dan reported this:

The patch 2984c8684f: "nullb: factor disk parameters" from Aug 14,
2017, leads to the following Smatch complaint:

drivers/block/null_blk.c:1759 null_init_tag_set()
	 error: we previously assumed 'nullb' could be null (see line
1750)

  1755		set->cmd_size	= sizeof(struct nullb_cmd);
  1756		set->flags = BLK_MQ_F_SHOULD_MERGE;
  1757		set->driver_data = NULL;
  1758
  1759		if (nullb->dev->blocking)
                    ^^^^^^^^^^^^^^^^^^^^
And an unchecked dereference.

nullb could be NULL here.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-25 14:52:01 -06:00
Jens Axboe
231b3db18d null_blk: update email adress
Update to a working one, the fusionio address hasn't been valid
in 4 years.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-25 12:53:15 -06:00
Shaohua Li
2f54a613c9 nullb: badbblocks support
Sometime disk could have tracks broken and data there is inaccessable,
but data in other parts can be accessed in normal way. MD RAID supports
such disks. But we don't have a good way to test it, because we can't
control which part of a physical disk is bad. For a virtual disk, this
can be easily controlled.

This patch adds a new 'badblock' attribute. Configure it in this way:
echo "+1-100" > xxx/badblock, this will make sector [1-100] as bad
blocks.
echo "-20-30" > xxx/badblock, this will make sector [20-30] good

If badblocks are accessed, the nullb disk will return IO error. Other
parts of the disk can accessed in normal way.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 08:54:12 -06:00
Shaohua Li
deb78b419d nullb: emulate cache
Software must flush disk cache to guarantee data safety. To check if
software correctly does disk cache flush, we must know the behavior of
disk. But physical disk behavior is uncontrollable. Even software
doesn't do the flush, the disk probably does the flush. This patch tries
to emulate a cache in the test disk.

All write will go to a cache first, when the cache is full, we then
flush some data to disk storage. A flush request will flush all data of
the cache to disk storage. A FUA write will write to memory store
directly and revalidate data in cache. If there is a power failure (by
writing to power attribute, 'echo 0 > disk_name/power'), we discard all
data in the cache, but preserve the data in disk storage. Later we can
power on the disk again as usual (write 1 to 'power' attribute), then we
can check data integrity and very if software does everything correctly.

A new attribute 'cache_size' (in MB) is added to configure cache size.

Based on original patch from Kyungchan Koh

Signed-off-by: Kyungchan Koh <kkc6196@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 08:54:11 -06:00
Shaohua Li
eff2c4f108 nullb: bandwidth control
In test, we usually expect controllable disk speed. For example, in a
raid array, we'd like some disks are fast and some are slow. MD RAID
actually has a feature for this. To test the feature, we'd like to make
the disk run in specific speed.

block throttling probably can be used for this purpose, but it requires
cgroup setup. Here we just implement a simple throttling mechanism in
the driver. There is slight fluctuation in the mechanism, but it's good
enough for test.

To configure the bandwidth cap, user sets the 'mbps' attribute. mbps is
MB/s.

Based on original patch from Kyungchan Koh

Signed-off-by: Kyungchan Koh <kkc6196@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 08:54:09 -06:00
Shaohua Li
306eb6b4ad nullb: support discard
discard makes sense for memory backed disk. And also it's useful to test
if upper layer supports dicard correctly.

User configures 'discard' attribute to enable/disable dicard support.

Based on original patch from Kyungchan Koh

Signed-off-by: Kyungchan Koh <kkc6196@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 08:54:08 -06:00
Shaohua Li
5bcd0e0c79 nullb: support memory backed store
This adds memory backed store in nullb.

User configure 'memory_backed' attribute for this. By default, nullb
disk doesn't use memory backed store.

Based on original patch from Kyungchan Koh

Signed-off-by: Kyungchan Koh <kkc6196@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 08:54:06 -06:00
Shaohua Li
94bc02e30f nullb: use ida to manage index
We now dynamically create disks. Managing the disk index with ida to
avoid bump up the index too much.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 08:54:05 -06:00
Shaohua Li
cedcafad82 nullb: add interface to power on disk
The device created in nullb configfs interface isn't power on by
default. After user configures the device, user can do 'echo 1 >
xxx/nullb/device_name/power' to power on the device, which will create a
disk. the xxx/nullb/device_name/index is the disk index, so if the index
is 2, the new created disk should be named as /dev/nullb2. Note, the
'index' is only valid after disk is power on.

'echo 0 > xxx/nullb/device_name/power' will remove the disk. Note, this
doesn't remove the device. To remove the device, user should do 'rmdir
xxx/nullb/device_name'. Removing the device will remove the disk too.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 08:54:03 -06:00
Shaohua Li
3bf2bd2073 nullb: add configfs interface
Add configfs interface for nullb. configfs interface is more flexible
and easy to configure in a per-disk basis.

Configuration is something like this:
mount -t configfs none /mnt

Checking which features the driver supports:
cat /mnt/nullb/features

The 'features' attribute is for future extension. We probably will add
new features into the driver, userspace can check this attribute to find
the supported features.

Create/remove a device:
mkdir/rmdir /mnt/nullb/a

Then configure the device by setting attributes under /mnt/nullb/a, most
of nullb supported module parameters are converted to attributes:
size; /* device size in MB */
completion_nsec; /* time in ns to complete a request */
submit_queues; /* number of submission queues */
home_node; /* home node for the device */
queue_mode; /* block interface */
blocksize; /* block size */
irqmode; /* IRQ completion handler */
hw_queue_depth; /* queue depth */
use_lightnvm; /* register as a LightNVM device */
blocking; /* blocking blk-mq device */
use_per_node_hctx; /* use per-node allocation for hardware context */

Note, creating a device doesn't create a disk immediately. Creating a
disk is done in two phases: create a device and then power on the
device. Next patch will introduce device power on.

Based on original patch from Kyungchan Koh

Signed-off-by: Kyungchan Koh <kkc6196@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 08:54:02 -06:00
Shaohua Li
2984c8684f nullb: factor disk parameters
When we switch to configfs interface, each disk could have different
configuration. To prepare for the change, we move most disk setting to a
separate data structure. The existing module parameter interface is
kept. The 'nr_devices' and 'shared_tags' don't make sense for per-disk
setting, so they are remained as global settings.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 08:54:00 -06:00
weiping zhang
d424681cc9 null_blk: make sure submit_queues > 0
set submit_queues to 1 by default, and make sure it's value > 0.

Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-07 15:15:38 -06:00
weiping zhang
558ab300c8 null_blk: simplify logic for use_per_node_hctx
make sure submit_queues equal nr_online_nodes.

Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-07 15:15:37 -06:00
Max Gurtovoy
db2d153d7a null_blk: fix error flow for shared tags during module_init
In case we use shared tags feature, blk_mq_alloc_tag_set might fail
during module initialization. In that case, fail the load with a
suitable error code. Also move the tagset initialization process after
defining the amount of submission queues.

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-06 09:52:09 -06:00
Jens Axboe
82f402fefa null_blk: add support for shared tags
Some storage drivers need to share tag sets between devices. It's
useful to be able to model that with null_blk, to find hangs or
performance issues.

Add a 'shared_tags' bool module parameter that. If that is set to
true and nr_devices is bigger than 1, all devices allocated will
share the same tag set.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-20 14:22:01 -06:00
Christoph Hellwig
fc17b6534e blk-mq: switch ->queue_rq return value to blk_status_t
Use the same values for use for request completion errors as the return
value from ->queue_rq.  BLK_STS_RESOURCE is special cased to cause
a requeue, and all the others are completed as-is.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00
Christoph Hellwig
2a842acab1 block: introduce new block status code type
Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings.  This patch
instead introduces a new  blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning.  Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.

For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.

blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00
Christoph Hellwig
08e0029aa2 blk-mq: remove the error argument to blk_mq_complete_request
Now that all drivers that call blk_mq_complete_requests have a
->complete callback we can remove the direct call to blk_mq_end_request,
as well as the error argument to blk_mq_complete_request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20 12:16:10 -06:00
Christoph Hellwig
eb1a61a363 null_blk: don't pass always-0 req->errors to blk_mq_complete_request
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20 12:16:10 -06:00
Bart Van Assche
2644a3ccee null_blk: Use blk_init_request_from_bio() instead of open-coding it
This patch changes the behavior of the null_blk driver for the
LightNVM mode as follows:
* REQ_FAILFAST_MASK is set for read-ahead requests.
* If no I/O priority has been set in the bio, the I/O priority is
  copied from the I/O context.
* The rq_disk member is initialized if bio->bi_bdev != NULL.
* req->errors is initialized to zero.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matias Bjørling <m@bjorling.me>
Cc: Adam Manzanares <adam.manzanares@wdc.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-19 17:38:31 -06:00
Eric Biggers
f363b089be blk-mq: constify struct blk_mq_ops
Constify all instances of blk_mq_ops, as they are never modified.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-31 08:28:58 -06:00
Jens Axboe
db5bcf87bb null_blk: add blocking mode
This adds a new module parameter to null_blk, blocking. If set, null_blk
will set the BLK_MQ_F_BLOCKING flag, indicating that it sometimes/always
needs to block in its ->queue_rq() function.  The intent is to help find
regressions in blocking drivers, since not many of them exist.

If null_blk is loaded with submit_queues > 1 and blocking=1, this
shows the regression recently fixed by bf4907c05e.

Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-30 13:44:26 -06:00
Jens Axboe
818551e2b2 Merge branch 'for-4.11/next' into for-4.11/linus-merge
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-17 14:08:19 -07:00
Christoph Hellwig
aebf526b53 block: fold cmd_type into the REQ_OP_ space
Instead of keeping two levels of indirection for requests types, fold it
all into the operations.  The little caveat here is that previously
cmd_type only applied to struct request, while the request and bio op
fields were set to plain REQ_OP_READ/WRITE even for passthrough
operations.

Instead this patch adds new REQ_OP_* for SCSI passthrough and driver
private requests, althought it has to add two for each so that we
can communicate the data in/out nature of the request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 14:00:44 -07:00
Matias Bjørling
06894efea7 lightnvm: use end_io callback instead of instance
When the lightnvm core had the "gennvm" layer between the device and the
target, there was a need for the core to be able to figure out which
target it should send an end_io callback to. Leading to a "double"
end_io, first for the media manager instance, and then for the target
instance. Now that core and gennvm is merged, there is no longer a need
for this, and a single end_io callback will do.

Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:32:13 -07:00
Matias Bjørling
19bd6fe73c lightnvm: reduce number of nvm_id groups to one
The number of configuration groups has been limited to one in current
code, even if there is support for up to four. With the introduction
of the open-channel SSD 1.3 specification, only a single
group is exposed onwards. Reflect this in the nvm_id structure.

Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:32:13 -07:00
Thomas Gleixner
8b0e195314 ktime: Cleanup ktime_set() usage
ktime_set(S,N) was required for the timespec storage type and is still
useful for situations where a Seconds and Nanoseconds part of a time value
needs to be converted. For anything where the Seconds argument is 0, this
is pointless and can be replaced with a simple assignment.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
2016-12-25 17:21:22 +01:00
Yasuaki Ishimatsu
92153d30c7 null_blk: add usage hints for NVM
If CONFIG_NVM is disabled, loading null_block module with use_lightnvm=1
fails. But there are no messages and documents related to the failure.

Add the appropriate error message.

Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>

Massaged the text a bit.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-16 08:26:11 -07:00
Linus Torvalds
12e3d3cdd9 Merge branch 'for-4.9/block-irq' of git://git.kernel.dk/linux-block
Pull blk-mq irq/cpu mapping updates from Jens Axboe:
 "This is the block-irq topic branch for 4.9-rc. It's mostly from
  Christoph, and it allows drivers to specify their own mappings, and
  more importantly, to share the blk-mq mappings with the IRQ affinity
  mappings. It's a good step towards making this work better out of the
  box"

* 'for-4.9/block-irq' of git://git.kernel.dk/linux-block:
  blk_mq: linux/blk-mq.h does not include all the headers it depends on
  blk-mq: kill unused blk_mq_create_mq_map()
  blk-mq: get rid of the cpumask in struct blk_mq_tags
  nvme: remove the post_scan callout
  nvme: switch to use pci_alloc_irq_vectors
  blk-mq: provide a default queue mapping for PCI device
  blk-mq: allow the driver to pass in a queue mapping
  blk-mq: remove ->map_queue
  blk-mq: only allocate a single mq_map per tag_set
  blk-mq: don't redistribute hardware queues on a CPU hotplug event
2016-10-09 17:29:33 -07:00
Matias Bjørling
b0b4e09c1a lightnvm: control life of nvm_dev in driver
LightNVM compatible device drivers does not have a method to expose
LightNVM specific sysfs entries.

To enable LightNVM sysfs entries to be exposed, lightnvm device
drivers require a struct device to attach it to. To allow both the
actual device driver and lightnvm sysfs entries to coexist, the device
driver tracks the lifetime of the nvm_dev structure.

This patch refactors NVMe and null_blk to handle the lifetime of struct
nvm_dev, which eliminates the need for struct gendisk when a lightnvm
compatible device is provided.

Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-21 07:56:18 -06:00
Matias Bjørling
9ae2d0aa50 null_blk: refactor to support non-gendisk devices
With LightNVM enabled devices, the gendisk structure is not exposed
to the user. This hides the device driver specific sysfs entries, and
prevents binding of LightNVM geometry information to the device.

Refactor the device registration process, so that gendisk and
non-gendisk devices are easily managed.

Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-21 07:56:14 -06:00
Christoph Hellwig
7d7e0f90b7 blk-mq: remove ->map_queue
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>
2016-09-15 08:42:03 -06:00
Christoph Hellwig
70246286e9 block: get rid of bio_rw and READA
These two are confusing leftover of the old world order, combining
values of the REQ_OP_ and REQ_ namespaces.  For callers that don't
special case we mostly just replace bi_rw with bio_data_dir or
op_is_write, except for the few cases where a switch over the REQ_OP_
values makes more sense.  Any check for READA is replaced with an
explicit check for REQ_RAHEAD.  Also remove the READA alias for
REQ_RAHEAD.

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>
2016-07-20 17:37:01 -06:00
Wenwei Tao
3681c85dff null_blk: add lightnvm null_blk device to the nullb_list
After register null_blk devices into lightnvm, we forget
to add these devices to the the nullb_list, makes them
invisible to the null_blk driver.

Signed-off-by: Wenwei Tao <ww.tao0320@gmail.com>
Fixes: a514379b0c ("null_blk: oops when initializing without lightnvm")
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-18 18:10:37 -07:00