Commit Graph

46 Commits

Author SHA1 Message Date
Max Gurtovoy
54d4e6ab91 block: centralize PI remapping logic to the block layer
Currently t10_pi_prepare/t10_pi_complete functions are called during the
NVMe and SCSi layers command preparetion/completion, but their actual
place should be the block layer since T10-PI is a general data integrity
feature that is used by block storage protocols. Introduce .prepare_fn
and .complete_fn callbacks within the integrity profile that each type
can implement according to its needs.

Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>

Fixed to not call queue integrity functions if BLK_DEV_INTEGRITY
isn't defined in the config.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-17 20:03:49 -06:00
Mauro Carvalho Chehab
898bd37a92 docs: block: convert to ReST
Rename the block documentation files to ReST, add an
index for them and adjust in order to produce a nice html
output via the Sphinx build system.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15 09:20:27 -03:00
Linus Torvalds
67a2422239 for-5.2/block-20190507
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Merge tag 'for-5.2/block-20190507' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "Nothing major in this series, just fixes and improvements all over the
  map. This contains:

   - Series of fixes for sed-opal (David, Jonas)

   - Fixes and performance tweaks for BFQ (via Paolo)

   - Set of fixes for bcache (via Coly)

   - Set of fixes for md (via Song)

   - Enabling multi-page for passthrough requests (Ming)

   - Queue release fix series (Ming)

   - Device notification improvements (Martin)

   - Propagate underlying device rotational status in loop (Holger)

   - Removal of mtip32xx trim support, which has been disabled for years
     (Christoph)

   - Improvement and cleanup of nvme command handling (Christoph)

   - Add block SPDX tags (Christoph)

   - Cleanup/hardening of bio/bvec iteration (Christoph)

   - A few NVMe pull requests (Christoph)

   - Removal of CONFIG_LBDAF (Christoph)

   - Various little fixes here and there"

* tag 'for-5.2/block-20190507' of git://git.kernel.dk/linux-block: (164 commits)
  block: fix mismerge in bvec_advance
  block: don't drain in-progress dispatch in blk_cleanup_queue()
  blk-mq: move cancel of hctx->run_work into blk_mq_hw_sysfs_release
  blk-mq: always free hctx after request queue is freed
  blk-mq: split blk_mq_alloc_and_init_hctx into two parts
  blk-mq: free hw queue's resource in hctx's release handler
  blk-mq: move cancel of requeue_work into blk_mq_release
  blk-mq: grab .q_usage_counter when queuing request from plug code path
  block: fix function name in comment
  nvmet: protect discovery change log event list iteration
  nvme: mark nvme_core_init and nvme_core_exit static
  nvme: move command size checks to the core
  nvme-fabrics: check more command sizes
  nvme-pci: check more command sizes
  nvme-pci: remove an unneeded variable initialization
  nvme-pci: unquiesce admin queue on shutdown
  nvme-pci: shutdown on timeout during deletion
  nvme-pci: fix psdt field for single segment sgls
  nvme-multipath: don't print ANA group state by default
  nvme-multipath: split bios with the ns_head bio_set before submitting
  ...
2019-05-07 18:14:36 -07:00
Christoph Hellwig
8c16567d86 block: switch all files cleared marked as GPLv2 to SPDX tags
All these files have some form of the usual GPLv2 boilerplate.  Switch
them to use SPDX tags instead.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30 16:11:57 -06:00
Kimberly Brown
800f5aa1e7 block: Replace all ktype default_attrs with groups
The kobj_type default_attrs field is being replaced by the
default_groups field. Replace all of the ktype default_attrs fields in
the block subsystem with default_groups and use the ATTRIBUTE_GROUPS
macro to create the default groups.

Remove default_ctx_attrs[] because it doesn't contain any attributes.

This patch was tested by verifying that the sysfs files for the
attributes in the default groups were created.

Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 22:06:11 +02:00
Christoph Hellwig
3dccdae54f block: merge BIOVEC_SEG_BOUNDARY into biovec_phys_mergeable
These two checks should always be performed together, so merge them into
a single helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-24 12:33:57 -06:00
Christoph Hellwig
6a9f5f240a block: simplify BIOVEC_PHYS_MERGEABLE
Turn the macro into an inline, move it to blk.h and simplify the
arch hooks a bit.

Also rename the function to biovec_phys_mergeable as there is no need
to shout.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-24 12:33:54 -06:00
Joe Perches
5657a819a8 block drivers/block: Use octal not symbolic permissions
Convert the S_<FOO> symbolic permissions to their octal equivalents as
using octal and not symbolic permissions is preferred by many as more
readable.

see: https://lkml.org/lkml/2016/8/2/1945

Done with automated conversion via:
$ ./scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace <files...>

Miscellanea:

o Wrapped modified multi-line calls to a single line where appropriate
o Realign modified multi-line calls to open parenthesis

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-24 13:38:59 -06:00
Christoph Hellwig
4e4cbee93d block: switch bios to blk_status_t
Replace bi_error with a new bi_status to allow for a clear conversion.
Note that device mapper overloaded bi_error with a private value, which
we'll have to keep arround at least for now and thus propagate to a
proper blk_status_t value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00
Mike Snitzer
2859323e35 block: fix blk_integrity_register to use template's interval_exp if not 0
When registering an integrity profile: if the template's interval_exp is
not 0 use it, otherwise use the ilog2() of logical block size of the
provided gendisk.

This fixes a long-standing DM linear target bug where it cannot pass
integrity data to the underlying device if its logical block size
conflicts with the underlying device's logical block size.

Cc: stable@vger.kernel.org
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-23 12:59:56 -06:00
Ilya Dryomov
19b7ccf865 block: get rid of blk_integrity_revalidate()
Commit 25520d55cd ("block: Inline blk_integrity in struct gendisk")
introduced blk_integrity_revalidate(), which seems to assume ownership
of the stable pages flag and unilaterally clears it if no blk_integrity
profile is registered:

    if (bi->profile)
            disk->queue->backing_dev_info->capabilities |=
                    BDI_CAP_STABLE_WRITES;
    else
            disk->queue->backing_dev_info->capabilities &=
                    ~BDI_CAP_STABLE_WRITES;

It's called from revalidate_disk() and rescan_partitions(), making it
impossible to enable stable pages for drivers that support partitions
and don't use blk_integrity: while the call in revalidate_disk() can be
trivially worked around (see zram, which doesn't support partitions and
hence gets away with zram_revalidate_disk()), rescan_partitions() can
be triggered from userspace at any time.  This breaks rbd, where the
ceph messenger is responsible for generating/verifying CRCs.

Since blk_integrity_{un,}register() "must" be used for (un)registering
the integrity profile with the block layer, move BDI_CAP_STABLE_WRITES
setting there.  This way drivers that call blk_integrity_register() and
use integrity infrastructure won't interfere with drivers that don't
but still want stable pages.

Fixes: 25520d55cd ("block: Inline blk_integrity in struct gendisk")
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 4.4+, needs backporting
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-21 14:17:27 -06:00
Eric Biggers
869ab90f0a block: constify struct blk_integrity_profile
blk_integrity_profile's are never modified, so mark them 'const' so that
they are placed in .rodata and benefit from memory protection.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-24 20:34:39 -06:00
Jan Kara
dc3b17cc8b block: Use pointer to backing_dev_info from request_queue
We will want to have struct backing_dev_info allocated separately from
struct request_queue. As the first step add pointer to backing_dev_info
to request_queue and convert all users touching it. No functional
changes in this patch.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02 08:20:48 -07:00
Dan Williams
4125a09b0a block, libnvdimm, nvme: provide a built-in blk_integrity nop profile
The libnvidmm-btt and nvme drivers use blk_integrity to reserve space
for per-sector metadata, but sometimes without protection checksums.
This property is generically useful, so teach the block core to
internally specify a nop profile if one is not provided at registration
time.

Cc: Keith Busch <keith.busch@intel.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
[hch: kill the local nvme nop profile as well]
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:43:45 -06:00
Dan Williams
ac6fc48c9f block: move blk_integrity to request_queue
A trace like the following proceeds a crash in bio_integrity_process()
when it goes to use an already freed blk_integrity profile.

 BUG: unable to handle kernel paging request at ffff8800d31b10d8
 IP: [<ffff8800d31b10d8>] 0xffff8800d31b10d8
 PGD 2f65067 PUD 21fffd067 PMD 80000000d30001e3
 Oops: 0011 [#1] SMP
 Dumping ftrace buffer:
 ---------------------------------
    ndctl-2222    2.... 44526245us : disk_release: pmem1s
 systemd--2223    4.... 44573945us : bio_integrity_endio: pmem1s
    <...>-409     4.... 44574005us : bio_integrity_process: pmem1s
 ---------------------------------
[..]
  Call Trace:
  [<ffffffff8144e0f9>] ? bio_integrity_process+0x159/0x2d0
  [<ffffffff8144e4f6>] bio_integrity_verify_fn+0x36/0x60
  [<ffffffff810bd2dc>] process_one_work+0x1cc/0x4e0

Given that a request_queue is pinned while i/o is in flight and that a
gendisk is allowed to have a shorter lifetime, move blk_integrity to
request_queue to satisfy requests arriving after the gendisk has been
torn down.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
[martin: fix the CONFIG_BLK_DEV_INTEGRITY=n case]
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:43:42 -06:00
Martin K. Petersen
25520d55cd block: Inline blk_integrity in struct gendisk
Up until now the_integrity profile has been dynamically allocated and
attached to struct gendisk after the disk has been made active.

This causes problems because NVMe devices need to register the profile
prior to the partition table being read due to a mandatory metadata
buffer requirement. In addition, DM goes through hoops to deal with
preallocating, but not initializing integrity profiles.

Since the integrity profile is small (4 bytes + a pointer), Christoph
suggested moving it to struct gendisk proper. This requires several
changes:

 - Moving the blk_integrity definition to genhd.h.

 - Inlining blk_integrity in struct gendisk.

 - Removing the dynamic allocation code.

 - Adding helper functions which allow gendisk to set up and tear down
   the integrity sysfs dir when a disk is added/deleted.

 - Adding a blk_integrity_revalidate() callback for updating the stable
   pages bdi setting.

 - The calls that depend on whether a device has an integrity profile or
   not now key off of the bi->profile pointer.

 - Simplifying the integrity support routines in DM (Mike Snitzer).

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:42:42 -06:00
Martin K. Petersen
4c241d08db block: Export integrity data interval size in sysfs
The size of the data interval was not exported in the sysfs integrity
directory. Export it so that userland apps can tell whether the interval
is different from the device's logical block size.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:42:41 -06:00
Martin K. Petersen
a48f041d91 block: Reduce the size of struct blk_integrity
The per-device properties in the blk_integrity structure were previously
unsigned short. However, most of the values fit inside a char. The only
exception is the data interval size and we can work around that by
storing it as a power of two.

This cuts the size of the dynamic portion of blk_integrity in half.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:42:39 -06:00
Martin K. Petersen
0f8087ecde block: Consolidate static integrity profile properties
We previously made a complete copy of a device's data integrity profile
even though several of the fields inside the blk_integrity struct are
pointers to fixed template entries in t10-pi.c.

Split the static and per-device portions so that we can reference the
template directly.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:42:38 -06:00
Martin K. Petersen
aff34e192e block: Move integrity kobject to struct gendisk
The integrity kobject purely exists to support the integrity
subdirectory in sysfs and doesn't really have anything to do with the
blk_integrity data structure. Move the kobject to struct gendisk where
it belongs.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:42:36 -06:00
Sagi Grimberg
7f39add3b0 block: Refuse request/bio merges with gaps in the integrity payload
If a driver sets the block queue virtual boundary mask, it means that
it cannot handle gaps so we must not allow those in the integrity
payload as well.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>

Fixed up by me to have duplicate integrity merge functions, depending
on whether block integrity is enabled or not. Fixes a compilations
issue with CONFIG_BLK_DEV_INTEGRITY unset.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-09-11 09:03:04 -06:00
Tejun Heo
66114cad64 writeback: separate out include/linux/backing-dev-defs.h
With the planned cgroup writeback support, backing-dev related
declarations will be more widely used across block and cgroup;
unfortunately, including backing-dev.h from include/linux/blkdev.h
makes cyclic include dependency quite likely.

This patch separates out backing-dev-defs.h which only has the
essential definitions and updates blkdev.h to include it.  c files
which need access to more backing-dev details now include
backing-dev.h directly.  This takes backing-dev.h off the common
include dependency chain making it a lot easier to use it across block
and cgroup.

v2: fs/fat build failure fixed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:34 -06:00
Martin K. Petersen
4eaf99bead block: Don't merge requests if integrity flags differ
We'd occasionally merge requests with conflicting integrity flags.
Introduce a merge helper which checks that the requests have compatible
integrity payloads.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-27 09:14:57 -06:00
Martin K. Petersen
3aec2f41a8 block: Add a disk flag to block integrity profile
So far we have relied on the app tag size to determine whether a disk
has been formatted with T10 protection information or not. However, not
all target devices provide application tag storage.

Add a flag to the block integrity profile that indicates whether the
disk has been formatted with protection information.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@dev.mellanox.co.il>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-27 09:14:51 -06:00
Martin K. Petersen
8288f496eb block: Add prefix to block integrity profile flags
Add a BLK_ prefix to the integrity profile flags. Also rename the flags
to be more consistent with the generate/verify terminology in the rest
of the integrity code.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-27 09:14:51 -06:00
Martin K. Petersen
3be91c4a3d block: Deprecate the use of the term sector in the context of block integrity
The protection interval is not necessarily tied to the logical block
size of a block device. Stop using the terms "sector" and "sectors".

Going forward we will use the term "seed" to describe the initial
reference tag value for a given I/O. "Interval" will be used to describe
the portion of the data buffer that a given piece of protection
information is associated with.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-27 09:14:50 -06:00
Martin K. Petersen
8492b68bc4 block: Remove integrity tagging functions
None of the filesystems appear interested in using the integrity tagging
feature. Potentially because very few storage devices actually permit
using the application tag space.

Remove the tagging functions.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-27 09:14:50 -06:00
Kent Overstreet
d57a5f7c66 bio-integrity: Convert to bvec_iter
The bio integrity is also stored in a bvec array, so if we use the bvec
iter code we just added, the integrity code won't need to implement its
own iteration stuff (bio_integrity_mark_head(), bio_integrity_mark_tail())

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
2013-11-23 22:33:50 -08:00
Paolo Bonzini
c8164d8931 scatterlist: introduce sg_unmark_end
This is useful in places that recycle the same scatterlist multiple
times, and do not want to incur the cost of sg_init_table every
time in hot paths.

Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-03-20 15:43:04 +10:30
Darrick J. Wong
7d311cdab6 bdi: allow block devices to say that they require stable page writes
This patchset ("stable page writes, part 2") makes some key
modifications to the original 'stable page writes' patchset.  First, it
provides creators (devices and filesystems) of a backing_dev_info a flag
that declares whether or not it is necessary to ensure that page
contents cannot change during writeout.  It is no longer assumed that
this is true of all devices (which was never true anyway).  Second, the
flag is used to relaxed the wait_on_page_writeback calls so that wait
only occurs if the device needs it.  Third, it fixes up the remaining
disk-backed filesystems to use this improved conditional-wait logic to
provide stable page writes on those filesystems.

It is hoped that (for people not using checksumming devices, anyway)
this patchset will give back unnecessary performance decreases since the
original stable page write patchset went into 3.0.  Sorry about not
fixing it sooner.

Complaints were registered by several people about the long write
latencies introduced by the original stable page write patchset.
Generally speaking, the kernel ought to allocate as little extra memory
as possible to facilitate writeout, but for people who simply cannot
wait, a second page stability strategy is (re)introduced: snapshotting
page contents.  The waiting behavior is still the default strategy; to
enable page snapshotting, a superblock flag (MS_SNAP_STABLE) must be
set.  This flag is used to bandaid^Henable stable page writeback on
ext3[1], and is not used anywhere else.

Given that there are already a few storage devices and network FSes that
have rolled their own page stability wait/page snapshot code, it would
be nice to move towards consolidating all of these.  It seems possible
that iscsi and raid5 may wish to use the new stable page write support
to enable zero-copy writeout.

Thank you to Jan Kara for helping fix a couple more filesystems.

Per Andrew Morton's request, here are the result of using dbench to measure
latencies on ext2:

3.8.0-rc3:
   Operation      Count    AvgLat    MaxLat
   ----------------------------------------
   WriteX        109347     0.028    59.817
   ReadX         347180     0.004     3.391
   Flush          15514    29.828   287.283

  Throughput 57.429 MB/sec  4 clients  4 procs  max_latency=287.290 ms

3.8.0-rc3 + patches:
   WriteX        105556     0.029     4.273
   ReadX         335004     0.005     4.112
   Flush          14982    30.540   298.634

  Throughput 55.4496 MB/sec  4 clients  4 procs  max_latency=298.650 ms

As you can see, for ext2 the maximum write latency decreases from ~60ms
on a laptop hard disk to ~4ms.  I'm not sure why the flush latencies
increase, though I suspect that being able to dirty pages faster gives
the flusher more work to do.

On ext4, the average write latency decreases as well as all the maximum
latencies:

3.8.0-rc3:
   WriteX         85624     0.152    33.078
   ReadX         272090     0.010    61.210
   Flush          12129    36.219   168.260

  Throughput 44.8618 MB/sec  4 clients  4 procs  max_latency=168.276 ms

3.8.0-rc3 + patches:
   WriteX         86082     0.141    30.928
   ReadX         273358     0.010    36.124
   Flush          12214    34.800   165.689

  Throughput 44.9941 MB/sec  4 clients  4 procs  max_latency=165.722 ms

XFS seems to exhibit similar latency improvements as ext2:

3.8.0-rc3:
   WriteX        125739     0.028   104.343
   ReadX         399070     0.005     4.115
   Flush          17851    25.004   131.390

  Throughput 66.0024 MB/sec  4 clients  4 procs  max_latency=131.406 ms

3.8.0-rc3 + patches:
   WriteX        123529     0.028     6.299
   ReadX         392434     0.005     4.287
   Flush          17549    25.120   188.687

  Throughput 64.9113 MB/sec  4 clients  4 procs  max_latency=188.704 ms

...and btrfs, just to round things out, also shows some latency
decreases:

3.8.0-rc3:
   WriteX         67122     0.083    82.355
   ReadX         212719     0.005     2.828
   Flush           9547    47.561   147.418

  Throughput 35.3391 MB/sec  4 clients  4 procs  max_latency=147.433 ms

3.8.0-rc3 + patches:
   WriteX         64898     0.101    71.631
   ReadX         206673     0.005     7.123
   Flush           9190    47.963   219.034

  Throughput 34.0795 MB/sec  4 clients  4 procs  max_latency=219.044 ms

Before this patchset, all filesystems would block, regardless of whether
or not it was necessary.  ext3 would wait, but still generate occasional
checksum errors.  The network filesystems were left to do their own
thing, so they'd wait too.

After this patchset, all the disk filesystems except ext3 and btrfs will
wait only if the hardware requires it.  ext3 (if necessary) snapshots
pages instead of blocking, and btrfs provides its own bdi so the mm will
never wait.  Network filesystems haven't been touched, so either they
provide their own wait code, or they don't block at all.  The blocking
behavior is back to what it was before 3.0 if you don't have a disk
requiring stable page writes.

This patchset has been tested on 3.8.0-rc3 on x64 with ext3, ext4, and
xfs.  I've spot-checked 3.8.0-rc4 and seem to be getting the same
results as -rc3.

[1] The alternative fixes to ext3 include fixing the locking order and
page bit handling like we did for ext4 (but then why not just use
ext4?), or setting PG_writeback so early that ext3 becomes extremely
slow.  I tried that, but the number of write()s I could initiate dropped
by nearly an order of magnitude.  That was a bit much even for the
author of the stable page series! :)

This patch:

Creates a per-backing-device flag that tracks whether or not pages must
be held immutable during writeout.  Eventually it will be used to waive
wait_for_page_writeback() if nothing requires stable pages.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-21 17:22:19 -08:00
Paul Gortmaker
d5decd3b95 block: add export.h to files using EXPORT_SYMBOL/THIS_MODULE macros
These files were getting <linux/module.h> via an implicit include
path, but we want to crush those out of existence since they cost
time during compiles of processing thousands of lines of headers
for no reason.  Give them the lightweight header that just contains
the EXPORT_SYMBOL infrastructure.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:31:12 -04:00
Mike Snitzer
a63a5cf84d dm: improve block integrity support
The current block integrity (DIF/DIX) support in DM is verifying that
all devices' integrity profiles match during DM device resume (which
is past the point of no return).  To some degree that is unavoidable
(stacked DM devices force this late checking).  But for most DM
devices (which aren't stacking on other DM devices) the ideal time to
verify all integrity profiles match is during table load.

Introduce the notion of an "initialized" integrity profile: a profile
that was blk_integrity_register()'d with a non-NULL 'blk_integrity'
template.  Add blk_integrity_is_initialized() to allow checking if a
profile was initialized.

Update DM integrity support to:
- check all devices with _initialized_ integrity profiles match
  during table load; uninitialized profiles (e.g. for underlying DM
  device(s) of a stacked DM device) are ignored.
- disallow a table load that would result in an integrity profile that
  conflicts with a DM device's existing (in-use) integrity profile
- avoid clearing an existing integrity profile
- validate all integrity profiles match during resume; but if they
  don't all we can do is report the mismatch (during resume we're past
  the point of no return)

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-04-05 23:52:43 +02:00
Martin K. Petersen
e817bf3f68 block: Fix double free in blk_integrity_unregister
Commit 3839e4b introduced a kobject_put but failed to remove the
kmem_cache_free beneath it, leading to a double free.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-15 15:49:18 +02:00
Martin K. Petersen
13f05c8d8e block/scsi: Provide a limit on the number of integrity segments
Some controllers have a hardware limit on the number of protection
information scatter-gather list segments they can handle.

Introduce a max_integrity_segments limit in the block layer and provide
a new scsi_host_template setting that allows HBA drivers to provide a
value suitable for the hardware.

Add support for honoring the integrity segment limit when merging both
bios and requests.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
2010-09-10 20:50:10 +02:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Emese Revfy
52cf25d0ab Driver core: Constify struct sysfs_ops in struct kobj_type
Constify struct sysfs_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:49 -08:00
Xiaotian Feng
3839e4b29b block: fix improper kobject release in blk_integrity_unregister
blk_integrity_unregister should use kobject_put to release the kobject,
otherwise after bi is freed, memory of bi->kobj->name is leaked.

Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-07-28 09:11:14 +02:00
Martin K. Petersen
e1defc4ff0 block: Do away with the notion of hardsect_size
Until now we have had a 1:1 mapping between storage device physical
block size and the logical block sized used when addressing the device.
With SATA 4KB drives coming out that will no longer be the case.  The
sector size will be 4KB but the logical block size will remain
512-bytes.  Hence we need to distinguish between the physical block size
and the logical ditto.

This patch renames hardsect_size to logical_block_size.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-22 23:22:54 +02:00
Martin K. Petersen
322316385d block: Allow empty integrity profile
Allow a block device to allocate and register an integrity profile
without providing a template.  This allows DM to preallocate a profile
to avoid deadlocks during table reconfiguration.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30 12:34:36 +01:00
Martin K. Petersen
ad7fce9314 block: Switch blk_integrity_compare from bdev to gendisk
The DM and MD integrity support now depends on being able to use
gendisks instead of block_devices when comparing integrity profiles.
Change function parameters accordingly.

Also update comparison logic so that two NULL profiles are a valid
configuration.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09 08:56:21 +02:00
Martin K. Petersen
0c032ab889 block: Fix double put in blk_integrity_unregister
- kobject_del already puts the parent.

 - Set integrity profile to NULL to prevent stale data.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09 08:56:21 +02:00
Tejun Heo
ed9e198234 block: implement and use {disk|part}_to_dev()
Implement {disk|part}_to_dev() and use them to access generic device
instead of directly dereferencing {disk|part}->dev.  To make sure no
user is left behind, rename generic devices fields to __dev.

This is in preparation of unifying partition 0 handling with other
partitions.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09 08:56:07 +02:00
Randy Dunlap
710027a48e Add some block/ source files to the kernel-api docbook. Fix kernel-doc notation in them as needed. Fix changed function parameter names. Fix typos/spellos. In comments, change REQ_SPECIAL to REQ_TYPE_SPECIAL and REQ_BLOCK_PC to REQ_TYPE_BLOCK_PC.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09 08:56:03 +02:00
Jens Axboe
b24498d477 block: integrity flags can't use bit ops on unsigned short
Just use normal open coded bit operations instead, they need not be
atomic.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-03 13:21:15 +02:00
Jens Axboe
b984679efe block: integrity checkpatch cleanups
> 80 char lines and that sort of thing.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-03 13:21:13 +02:00
Martin K. Petersen
7ba1ba12ee block: Block layer data integrity support
Some block devices support verifying the integrity of requests by way
of checksums or other protection information that is submitted along
with the I/O.

This patch implements support for generating and verifying integrity
metadata, as well as correctly merging, splitting and cloning bios and
requests that have this extra information attached.

See Documentation/block/data-integrity.txt for more information.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-03 13:21:13 +02:00