06 Oct, 2020
2 commits
-
Also move the definition from the public blkdev.h to the private
block/blk.h header.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe -
Also move the definition from the public blkdev.h to the private
block/blk.h header.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
25 Sep, 2020
1 commit
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The BDI_CAP_STABLE_WRITES is one of the few bits of information in the
backing_dev_info shared between the block drivers and the writeback code.
To help untangling the dependency replace it with a queue flag and a
superblock flag derived from it. This also helps with the case of e.g.
a file system requiring stable writes due to its own checksumming, but
not forcing it on other users of the block device like the swap code.One downside is that we an't support the stable_pages_required bdi
attribute in sysfs anymore. It is replaced with a queue attribute which
also is writable for easier testing.Signed-off-by: Christoph Hellwig
Reviewed-by: Jan Kara
Reviewed-by: Johannes Thumshirn
Signed-off-by: Jens Axboe
14 May, 2020
1 commit
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Whenever a device supports blk-integrity, make the kernel pretend that
the device doesn't support inline encryption (essentially by setting the
keyslot manager in the request queue to NULL).There's no hardware currently that supports both integrity and inline
encryption. However, it seems possible that there will be such hardware
in the near future (like the NVMe key per I/O support that might support
both inline encryption and PI).But properly integrating both features is not trivial, and without
real hardware that implements both, it is difficult to tell if it will
be done correctly by the majority of hardware that support both.
So it seems best not to support both features together right now, and
to decide what to do at probe time.Signed-off-by: Satya Tangirala
Reviewed-by: Eric Biggers
Reviewed-by: Christoph Hellwig
Signed-off-by: Jens Axboe
18 Sep, 2019
1 commit
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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
Reviewed-by: Christoph Hellwig
Suggested-by: Martin K. Petersen
Reviewed-by: Martin K. Petersen
Signed-off-by: Max GurtovoyFixed to not call queue integrity functions if BLK_DEV_INTEGRITY
isn't defined in the config.Signed-off-by: Jens Axboe
15 Jul, 2019
1 commit
-
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
08 May, 2019
1 commit
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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
...
01 May, 2019
1 commit
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All these files have some form of the usual GPLv2 boilerplate. Switch
them to use SPDX tags instead.Reviewed-by: Chaitanya Kulkarni
Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
26 Apr, 2019
1 commit
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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
Reviewed-by: Bart Van Assche
Signed-off-by: Greg Kroah-Hartman
25 Sep, 2018
2 commits
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These two checks should always be performed together, so merge them into
a single helper.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe -
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
Signed-off-by: Jens Axboe
25 May, 2018
1 commit
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Convert the S_ 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-inplaceMiscellanea:
o Wrapped modified multi-line calls to a single line where appropriate
o Realign modified multi-line calls to open parenthesisSigned-off-by: Joe Perches
Signed-off-by: Jens Axboe
09 Jun, 2017
1 commit
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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
Signed-off-by: Jens Axboe
24 Apr, 2017
1 commit
-
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
Signed-off-by: Mike Snitzer
Acked-by: Martin K. Petersen
Signed-off-by: Jens Axboe
22 Apr, 2017
1 commit
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Commit 25520d55cdb6 ("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: 25520d55cdb6 ("block: Inline blk_integrity in struct gendisk")
Cc: "Martin K. Petersen"
Cc: Christoph Hellwig
Cc: Mike Snitzer
Cc: stable@vger.kernel.org # 4.4+, needs backporting
Tested-by: Dan Williams
Signed-off-by: Ilya Dryomov
Signed-off-by: Jens Axboe
25 Mar, 2017
1 commit
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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
Signed-off-by: Jens Axboe
02 Feb, 2017
1 commit
-
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
Signed-off-by: Jan Kara
Signed-off-by: Jens Axboe
22 Oct, 2015
7 commits
-
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
Cc: Matthew Wilcox
Suggested-by: Christoph Hellwig
[hch: kill the local nvme nop profile as well]
Acked-by: Martin K. Petersen
Signed-off-by: Dan Williams
Signed-off-by: Jens Axboe -
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: [] 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:
[] ? bio_integrity_process+0x159/0x2d0
[] bio_integrity_verify_fn+0x36/0x60
[] process_one_work+0x1cc/0x4e0Given 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
Cc: Martin K. Petersen
[martin: fix the CONFIG_BLK_DEV_INTEGRITY=n case]
Tested-by: Ross Zwisler
Signed-off-by: Dan Williams
Signed-off-by: Jens Axboe -
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
Reported-by: Christoph Hellwig
Reviewed-by: Sagi Grimberg
Signed-off-by: Mike Snitzer
Cc: Dan Williams
Signed-off-by: Dan Williams
Signed-off-by: Jens Axboe -
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
Reviewed-by: Sagi Grimberg
Signed-off-by: Dan Williams
Signed-off-by: Jens Axboe -
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
Reported-by: Christoph Hellwig
Reviewed-by: Sagi Grimberg
Signed-off-by: Dan Williams
Signed-off-by: Jens Axboe -
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
Reported-by: Christoph Hellwig
Reviewed-by: Sagi Grimberg
Cc: Dan Williams
Signed-off-by: Dan Williams
Signed-off-by: Jens Axboe -
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
Reported-by: Christoph Hellwig
Reviewed-by: Sagi Grimberg
Signed-off-by: Dan Williams
Signed-off-by: Jens Axboe
11 Sep, 2015
1 commit
-
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
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
02 Jun, 2015
1 commit
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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
Reviewed-by: Jan Kara
Cc: Jens Axboe
Signed-off-by: Jens Axboe
27 Sep, 2014
5 commits
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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
Reviewed-by: Christoph Hellwig
Reviewed-by: Sagi Grimberg
Signed-off-by: Jens Axboe -
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
Reviewed-by: Sagi Grimberg
Signed-off-by: Jens Axboe -
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
Reviewed-by: Christoph Hellwig
Reviewed-by: Sagi Grimberg
Signed-off-by: Jens Axboe -
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
Reviewed-by: Christoph Hellwig
Reviewed-by: Sagi Grimberg
Signed-off-by: Jens Axboe -
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
Reviewed-by: Christoph Hellwig
Reviewed-by: Sagi Grimberg
Signed-off-by: Jens Axboe
24 Nov, 2013
1 commit
-
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
Cc: Jens Axboe
Cc: "Martin K. Petersen"
Cc: "James E.J. Bottomley"
20 Mar, 2013
1 commit
-
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
Signed-off-by: Paolo Bonzini
Signed-off-by: Rusty Russell
22 Feb, 2013
1 commit
-
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 29.828 287.283Throughput 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 30.540 298.634Throughput 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 36.219 168.260Throughput 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 34.800 165.689Throughput 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 25.004 131.390Throughput 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 25.120 188.687Throughput 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 47.561 147.418Throughput 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 47.963 219.034Throughput 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
Reviewed-by: Jan Kara
Cc: Adrian Hunter
Cc: Andy Lutomirski
Cc: Artem Bityutskiy
Cc: Joel Becker
Cc: Mark Fasheh
Cc: Steven Whitehouse
Cc: Jens Axboe
Cc: Eric Van Hensbergen
Cc: Ron Minnich
Cc: Latchesar Ionkov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Nov, 2011
1 commit
-
These files were getting 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
06 Apr, 2011
1 commit
-
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
Cc: Martin K. Petersen
Signed-off-by: Jens Axboe
15 Oct, 2010
1 commit
-
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
Signed-off-by: Jens Axboe
11 Sep, 2010
1 commit
-
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
Signed-off-by: Jens Axboe
30 Mar, 2010
1 commit
-
…it 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 allmodconfig8. 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>
08 Mar, 2010
1 commit
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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 sharingSigned-off-by: Emese Revfy
Acked-by: David Teigland
Acked-by: Matt Domsch
Acked-by: Maciej Sosnowski
Acked-by: Hans J. Koch
Acked-by: Pekka Enberg
Acked-by: Jens Axboe
Acked-by: Stephen Hemminger
Signed-off-by: Greg Kroah-Hartman
