14 Nov, 2018
1 commit
-
commit 1adfc5e4136f5967d591c399aff95b3b035f16b7 upstream.
Obviously the created discard bio has to be aligned with logical block size.
This patch introduces the helper of bio_allowed_max_sectors() for
this purpose.Cc: stable@vger.kernel.org
Cc: Mike Snitzer
Cc: Christoph Hellwig
Cc: Xiao Ni
Cc: Mariusz Dabrowski
Fixes: 744889b7cbb56a6 ("block: don't deal with discard limit in blkdev_issue_discard()")
Fixes: a22c4d7e34402cc ("block: re-add discard_granularity and alignment checks")
Reported-by: Rui Salvaterra
Tested-by: Rui Salvaterra
Signed-off-by: Ming Lei
Signed-off-by: Jens Axboe
Signed-off-by: Greg Kroah-Hartman
03 Jun, 2018
1 commit
-
If we end up splitting a bio and the queue goes away between
the initial submission and the later split submission, then we
can block forever in blk_queue_enter() waiting for the reference
to drop to zero. This will never happen, since we already hold
a reference.Mark a split bio as already having entered the queue, so we can
just use the live non-blocking queue enter variant.Thanks to Tetsuo Handa for the analysis.
Reported-by: syzbot+c4f9cebf9d651f6e54de@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe
31 May, 2018
1 commit
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Convert the core block functionality to embedded bio sets.
Reviewed-by: Christoph Hellwig
Signed-off-by: Kent Overstreet
Signed-off-by: Jens Axboe
09 May, 2018
1 commit
-
Currently, struct request has four timestamp fields:
- A start time, set at get_request time, in jiffies, used for iostats
- An I/O start time, set at start_request time, in ktime nanoseconds,
used for blk-stats (i.e., wbt, kyber, hybrid polling)
- Another start time and another I/O start time, used for cfq and bfqThese can all be consolidated into one start time and one I/O start
time, both in ktime nanoseconds, shaving off up to 16 bytes from struct
request depending on the kernel config.Signed-off-by: Omar Sandoval
Signed-off-by: Jens Axboe
02 Feb, 2018
1 commit
-
I ran into an issue on my laptop that triggered a bug on the
discard path:WARNING: CPU: 2 PID: 207 at drivers/nvme/host/core.c:527 nvme_setup_cmd+0x3d3/0x430
Modules linked in: rfcomm fuse ctr ccm bnep arc4 binfmt_misc snd_hda_codec_hdmi nls_iso8859_1 nls_cp437 vfat snd_hda_codec_conexant fat snd_hda_codec_generic iwlmvm snd_hda_intel snd_hda_codec snd_hwdep mac80211 snd_hda_core snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq x86_pkg_temp_thermal intel_powerclamp kvm_intel uvcvideo iwlwifi btusb snd_seq_device videobuf2_vmalloc btintel videobuf2_memops kvm snd_timer videobuf2_v4l2 bluetooth irqbypass videobuf2_core aesni_intel aes_x86_64 crypto_simd cryptd snd glue_helper videodev cfg80211 ecdh_generic soundcore hid_generic usbhid hid i915 psmouse e1000e ptp pps_core xhci_pci xhci_hcd intel_gtt
CPU: 2 PID: 207 Comm: jbd2/nvme0n1p7- Tainted: G U 4.15.0+ #176
Hardware name: LENOVO 20FBCTO1WW/20FBCTO1WW, BIOS N1FET59W (1.33 ) 12/19/2017
RIP: 0010:nvme_setup_cmd+0x3d3/0x430
RSP: 0018:ffff880423e9f838 EFLAGS: 00010217
RAX: 0000000000000000 RBX: ffff880423e9f8c8 RCX: 0000000000010000
RDX: ffff88022b200010 RSI: 0000000000000002 RDI: 00000000327f0000
RBP: ffff880421251400 R08: ffff88022b200000 R09: 0000000000000009
R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000ffff
R13: ffff88042341e280 R14: 000000000000ffff R15: ffff880421251440
FS: 0000000000000000(0000) GS:ffff880441500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b684795030 CR3: 0000000002e09006 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
nvme_queue_rq+0x40/0xa00
? __sbitmap_queue_get+0x24/0x90
? blk_mq_get_tag+0xa3/0x250
? wait_woken+0x80/0x80
? blk_mq_get_driver_tag+0x97/0xf0
blk_mq_dispatch_rq_list+0x7b/0x4a0
? deadline_remove_request+0x49/0xb0
blk_mq_do_dispatch_sched+0x4f/0xc0
blk_mq_sched_dispatch_requests+0x106/0x170
__blk_mq_run_hw_queue+0x53/0xa0
__blk_mq_delay_run_hw_queue+0x83/0xa0
blk_mq_run_hw_queue+0x6c/0xd0
blk_mq_sched_insert_request+0x96/0x140
__blk_mq_try_issue_directly+0x3d/0x190
blk_mq_try_issue_directly+0x30/0x70
blk_mq_make_request+0x1a4/0x6a0
generic_make_request+0xfd/0x2f0
? submit_bio+0x5c/0x110
submit_bio+0x5c/0x110
? __blkdev_issue_discard+0x152/0x200
submit_bio_wait+0x43/0x60
ext4_process_freed_data+0x1cd/0x440
? account_page_dirtied+0xe2/0x1a0
ext4_journal_commit_callback+0x4a/0xc0
jbd2_journal_commit_transaction+0x17e2/0x19e0
? kjournald2+0xb0/0x250
kjournald2+0xb0/0x250
? wait_woken+0x80/0x80
? commit_timeout+0x10/0x10
kthread+0x111/0x130
? kthread_create_worker_on_cpu+0x50/0x50
? do_group_exit+0x3a/0xa0
ret_from_fork+0x1f/0x30
Code: 73 89 c1 83 ce 10 c1 e1 10 09 ca 83 f8 04 0f 87 0f ff ff ff 8b 4d 20 48 8b 7d 00 c1 e9 09 48 01 8c c7 00 08 00 00 e9 f8 fe ff ff ff 4c 89 c7 41 bc 0a 00 00 00 e8 0d 78 d6 ff e9 a1 fc ff ff
---[ end trace 50d361cc444506c8 ]---
print_req_error: I/O error, dev nvme0n1, sector 847167488Decoding the assembly, the request claims to have 0xffff segments,
while nvme counts two. This turns out to be because we don't check
for a data carrying request on the mq scheduler path, and since
blk_phys_contig_segment() returns true for a non-data request,
we decrement the initial segment count of 0 and end up with
0xffff in the unsigned short.There are a few issues here:
1) We should initialize the segment count for a discard to 1.
2) The discard merging is currently using the data limits for
segments and sectors.Fix this up by having attempt_merge() correctly identify the
request, and by initializing the segment count correctly
for discards.This can only be triggered with mq-deadline on discard capable
devices right now, which isn't a common configuration.Signed-off-by: Jens Axboe
10 Jan, 2018
1 commit
-
This reverts commit a2d37968d784363842f87820a21e106741d28004.
If max segment size isn't 512-aligned, this patch won't work well.
Also once multipage bvec is enabled, adjacent bvecs won't be physically
contiguous if page is added via bio_add_page(), so we don't need this
kind of complicated logic.Reported-by: Dmitry Osipenko
Signed-off-by: Ming Lei
Signed-off-by: Jens Axboe
07 Jan, 2018
3 commits
-
In this case, 'sectors' can't be zero at all, so remove the check
and let the bio be split.Reviewed-by: Christoph Hellwig
Signed-off-by: Ming Lei
Signed-off-by: Jens Axboe -
When merging one bvec into segment, if the bvec is too big
to merge, current policy is to move the whole bvec into another
new segment.This patchset changes the policy into trying to maximize size of
front segments, that means in above situation, part of bvec
is merged into current segment, and the remainder is put
into next segment.This patch prepares for support multipage bvec because
it can be quite common to see this case and we should try
to make front segments in full size.Signed-off-by: Ming Lei
Signed-off-by: Jens Axboe -
It is enough to check and compute bio->bi_seg_front_size just
after the 1st segment is found, but current code checks that
for each bvec, which is inefficient.This patch follows the way in __blk_recalc_rq_segments()
for computing bio->bi_seg_front_size, and it is more efficient
and code becomes more readable too.Signed-off-by: Ming Lei
Signed-off-by: Jens Axboe
02 Nov, 2017
1 commit
-
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.By default all files without license information are under the default
license of the kernel, which is GPL version 2.Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if
Reviewed-by: Philippe Ombredanne
Reviewed-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
24 Aug, 2017
1 commit
-
This way we don't need a block_device structure to submit I/O. The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open. Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).For the actual I/O path all that we need is the gendisk, which exists
once per block device. But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
10 Aug, 2017
1 commit
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No functional change in this patch, just in preparation for
basing the inflight mechanism on the queue in question.Reviewed-by: Bart Van Assche
Reviewed-by: Omar Sandoval
Signed-off-by: Jens Axboe
28 Jun, 2017
1 commit
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No functional changes in this patch, we just use up some holes
in the bio and request structures to define a write hint that
we psas down the stack.Ensure that we don't merge requests that have different life time
hints assigned to them, and that we inherit the write hint when
cloning a bio.Reviewed-by: Martin K. Petersen
Reviewed-by: Christoph Hellwig
Signed-off-by: Jens Axboe
21 Jun, 2017
1 commit
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Instead of documenting the locking assumptions of most block layer
functions as a comment, use lockdep_assert_held() to verify locking
assumptions at runtime.Signed-off-by: Bart Van Assche
Reviewed-by: Christoph Hellwig
Cc: Hannes Reinecke
Cc: Omar Sandoval
Cc: Ming Lei
Signed-off-by: Jens Axboe
19 Jun, 2017
4 commits
-
blk_bio_segment_split() makes sure bios have no more than
BIO_MAX_PAGES entries in the bi_io_vec.
This was done because bio_clone_bioset() (when given a
mempool bioset) could not handle larger io_vecs.No driver uses bio_clone_bioset() any more, they all
use bio_clone_fast() if anything, and bio_clone_fast()
doesn't clone the bi_io_vec.The main user of of bio_clone_bioset() at this level
is bounce.c, and bouncing now happens before blk_bio_segment_split(),
so that is not of concern.So remove the big helpful comment and the code.
Reviewed-by: Christoph Hellwig
Signed-off-by: NeilBrown
Signed-off-by: Jens Axboe -
bio_clone() is no longer used.
Only bio_clone_bioset() or bio_clone_fast().
This is for the best, as bio_clone() used fs_bio_set,
and filesystems are unlikely to want to use bio_clone().So remove bio_clone() and all references.
This includes a fix to some incorrect documentation.Reviewed-by: Christoph Hellwig
Reviewed-by: Ming Lei
Signed-off-by: NeilBrown
Signed-off-by: Jens Axboe -
Since commit 23688bf4f830 ("block: ensure to split after potentially
bouncing a bio") blk_queue_bounce() is called *before*
blk_queue_split().
This means that:
1/ the comments blk_queue_split() about bounce buffers are
irrelevant, and
2/ a very large bio (more than BIO_MAX_PAGES) will no longer be
split before it arrives at blk_queue_bounce(), leading to the
possibility that bio_clone_bioset() will fail and a NULL
will be dereferenced.Separately, blk_queue_bounce() shouldn't use fs_bio_set as the bio
being copied could be from the same set, and this could lead to a
deadlock.So:
- allocate 2 private biosets for blk_queue_bounce, one for
splitting enormous bios and one for cloning bios.
- add code to split a bio that exceeds BIO_MAX_PAGES.
- Fix up the comments in blk_queue_split()Credit-to: Ming Lei (suggested using single bio_for_each_segment loop)
Reviewed-by: Ming Lei
Reviewed-by: Christoph Hellwig
Signed-off-by: NeilBrown
Signed-off-by: Jens Axboe -
blk_queue_split() is always called with the last arg being q->bio_split,
where 'q' is the first arg.Also blk_queue_split() sometimes uses the passed-in 'bs' and sometimes uses
q->bio_split.This is inconsistent and unnecessary. Remove the last arg and always use
q->bio_split inside blk_queue_split()Reviewed-by: Christoph Hellwig
Reviewed-by: Ming Lei
Credit-to: Javier González (Noticed that lightnvm was missed)
Reviewed-by: Javier González
Tested-by: Javier González
Signed-off-by: NeilBrown
Signed-off-by: Jens Axboe
09 Apr, 2017
1 commit
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Copy and past the REQ_OP_WRITE_SAME code to prepare to implementations
that limit the write zeroes size.Signed-off-by: Christoph Hellwig
Reviewed-by: Martin K. Petersen
Reviewed-by: Hannes Reinecke
Signed-off-by: Jens Axboe
09 Feb, 2017
3 commits
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Add a new merge strategy that merges discard bios into a request until the
maximum number of discard ranges (or the maximum discard size) is reached
from the plug merging code. I/O scheduler merging is not wired up yet
but might also be useful, although not for fast devices like NVMe which
are the only user for now.Note that for now we don't support limiting the size of each discard range,
but if needed that can be added later.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe -
Switch these constants to an enum, and make let the compiler ensure that
all callers of blk_try_merge and elv_merge handle all potential values.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe -
This makes it available outside of blk-merge.c, and inlining such a trivial
helper seems pretty useful to start with.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
04 Feb, 2017
2 commits
-
If we end up doing a request-to-request merge when we have completed
a bio-to-request merge, we free the request from deep down in that
path. For blk-mq-sched, the merge path has to hold the appropriate
lock, but we don't need it for freeing the request. And in fact
holding the lock is problematic, since we are now calling the
mq sched put_rq_private() hook with the lock held. Other call paths
do not hold this lock.Fix this inconsistency by ensuring that the caller frees a merged
request. Then we can do it outside of the lock, making it both more
efficient and fixing the blk-mq-sched problem of invoking parts of
the scheduler with an unknown lock state.Reported-by: Paolo Valente
Signed-off-by: Jens Axboe
Reviewed-by: Omar Sandoval -
When we attempt to merge request-to-request, we return a 0/1 if we
ended up merging or not. Change that to return the pointer to the
request that we freed. We will use this to move the freeing of
that request out of the merge logic, so that callers can drop
locks before freeing the request.There should be no functional changes in this patch.
Signed-off-by: Jens Axboe
Reviewed-by: Omar Sandoval
18 Jan, 2017
2 commits
-
This adds a set of hooks that intercepts the blk-mq path of
allocating/inserting/issuing/completing requests, allowing
us to develop a scheduler within that framework.We reuse the existing elevator scheduler API on the registration
side, but augment that with the scheduler flagging support for
the blk-mq interfce, and with a separate set of ops hooks for MQ
devices.We split driver and scheduler tags, so we can run the scheduling
independently of device queue depth.Signed-off-by: Jens Axboe
Reviewed-by: Bart Van Assche
Reviewed-by: Omar Sandoval -
Prep patch for adding MQ ops as well, since doing anon unions with
named initializers doesn't work on older compilers.Signed-off-by: Jens Axboe
Reviewed-by: Johannes Thumshirn
Reviewed-by: Bart Van Assche
Reviewed-by: Omar Sandoval
09 Dec, 2016
1 commit
-
Instead of allocating a single unused biovec for discard requests, send
them down without any payload. Instead we allow the driver to add a
"special" payload using a biovec embedded into struct request (unioned
over other fields never used while in the driver), and overloading
the number of segments for this case.This has a couple of advantages:
- we don't have to allocate the bio_vec
- the amount of special casing for discard requests in the block
layer is significantly reduced
- using this same scheme for other request types is trivial,
which will be important for implementing the new WRITE_ZEROES
op on devices where it actually requires a payload (e.g. SCSI)
- we can get rid of playing games with the request length, as
we'll never touch it and completions will work just fine
- it will allow us to support ranged discard operations in the
future by merging non-contiguous discard bios into a single
request
- last but not least it removes a lot of codeThis patch is the common base for my WIP series for ranges discards and to
remove discard_zeroes_data in favor of always using REQ_OP_WRITE_ZEROES,
so it would be good to get it in quickly.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
01 Dec, 2016
2 commits
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Factor out common code for setting REQ_NOMERGE flag which is being used
out at certain places and make it a helper instead, req_set_nomerge().Signed-off-by: Ritesh Harjani
Get rid of the inline.
Signed-off-by: Jens Axboe
-
This adds a new block layer operation to zero out a range of
LBAs. This allows to implement zeroing for devices that don't use
either discard with a predictable zero pattern or WRITE SAME of zeroes.
The prominent example of that is NVMe with the Write Zeroes command,
but in the future, this should also help with improving the way
zeroing discards work. For this operation, suitable entry is exported in
sysfs which indicate the number of maximum bytes allowed in one
write zeroes operation by the device.Signed-off-by: Chaitanya Kulkarni
Reviewed-by: Christoph Hellwig
Signed-off-by: Jens Axboe
28 Oct, 2016
1 commit
-
A lot of the REQ_* flags are only used on struct requests, and only of
use to the block layer and a few drivers that dig into struct request
internals.This patch adds a new req_flags_t rq_flags field to struct request for
them, and thus dramatically shrinks the number of common requests. It
also removes the unfortunate situation where we have to fit the fields
from the same enum into 32 bits for struct bio and 64 bits for
struct request.Signed-off-by: Christoph Hellwig
Reviewed-by: Shaun Tancheff
Signed-off-by: Jens Axboe
24 Aug, 2016
1 commit
-
After arbitrary bio size was introduced, the incoming bio may
be very big. We have to split the bio into small bios so that
each holds at most BIO_MAX_PAGES bvecs for safety reason, such
as bio_clone().This patch fixes the following kernel crash:
> [ 172.660142] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
> [ 172.660229] IP: [] bio_trim+0xf/0x2a
> [ 172.660289] PGD 7faf3e067 PUD 7f9279067 PMD 0
> [ 172.660399] Oops: 0000 [#1] SMP
> [...]
> [ 172.664780] Call Trace:
> [ 172.664813] [] ? raid1_make_request+0x2e8/0xad7 [raid1]
> [ 172.664846] [] ? blk_queue_split+0x377/0x3d4
> [ 172.664880] [] ? md_make_request+0xf6/0x1e9 [md_mod]
> [ 172.664912] [] ? generic_make_request+0xb5/0x155
> [ 172.664947] [] ? prio_io+0x85/0x95 [bcache]
> [ 172.664981] [] ? register_cache_set+0x355/0x8d0 [bcache]
> [ 172.665016] [] ? register_bcache+0x1006/0x1174 [bcache]The issue can be reproduced by the following steps:
- create one raid1 over two virtio-blk
- build bcache device over the above raid1 and another cache device
and bucket size is set as 2Mbytes
- set cache mode as writeback
- run random write over ext4 on the bcache deviceFixes: 54efd50(block: make generic_make_request handle arbitrarily sized bios)
Reported-by: Sebastian Roesner
Reported-by: Eric Wheeler
Cc: stable@vger.kernel.org (4.3+)
Cc: Shaohua Li
Acked-by: Kent Overstreet
Signed-off-by: Ming Lei
Signed-off-by: Jens Axboe
16 Aug, 2016
1 commit
-
Commit 288dab8a35a0 ("block: add a separate operation type for secure
erase") split REQ_OP_SECURE_ERASE from REQ_OP_DISCARD without considering
all the places REQ_OP_DISCARD was being used to mean either. Fix those.Signed-off-by: Adrian Hunter
Fixes: 288dab8a35a0 ("block: add a separate operation type for secure erase")
Signed-off-by: Jens Axboe
08 Aug, 2016
1 commit
-
Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower
portion and the op code in the higher portions. This means that
old code that relies on manually setting bi_rw is most likely
going to be broken. Instead of letting that brokeness linger,
rename the member, to force old and out-of-tree code to break
at compile time instead of at runtime.No intended functional changes in this commit.
Signed-off-by: Jens Axboe
27 Jul, 2016
1 commit
-
Pull block driver updates from Jens Axboe:
"This branch also contains core changes. I've come to the conclusion
that from 4.9 and forward, I'll be doing just a single branch. We
often have dependencies between core and drivers, and it's hard to
always split them up appropriately without pulling core into drivers
when that happens.That said, this contains:
- separate secure erase type for the core block layer, from
Christoph.- set of discard fixes, from Christoph.
- bio shrinking fixes from Christoph, as a followup up to the
op/flags change in the core branch.- map and append request fixes from Christoph.
- NVMeF (NVMe over Fabrics) code from Christoph. This is pretty
exciting!- nvme-loop fixes from Arnd.
- removal of ->driverfs_dev from Dan, after providing a
device_add_disk() helper.- bcache fixes from Bhaktipriya and Yijing.
- cdrom subchannel read fix from Vchannaiah.
- set of lightnvm updates from Wenwei, Matias, Johannes, and Javier.
- set of drbd updates and fixes from Fabian, Lars, and Philipp.
- mg_disk error path fix from Bart.
- user notification for failed device add for loop, from Minfei.
- NVMe in general:
+ NVMe delay quirk from Guilherme.
+ SR-IOV support and command retry limits from Keith.
+ fix for memory-less NUMA node from Masayoshi.
+ use UINT_MAX for discard sectors, from Minfei.
+ cancel IO fixes from Ming.
+ don't allocate unused major, from Neil.
+ error code fixup from Dan.
+ use constants for PSDT/FUSE from James.
+ variable init fix from Jay.
+ fabrics fixes from Ming, Sagi, and Wei.
+ various fixes"* 'for-4.8/drivers' of git://git.kernel.dk/linux-block: (115 commits)
nvme/pci: Provide SR-IOV support
nvme: initialize variable before logical OR'ing it
block: unexport various bio mapping helpers
scsi/osd: open code blk_make_request
target: stop using blk_make_request
block: simplify and export blk_rq_append_bio
block: ensure bios return from blk_get_request are properly initialized
virtio_blk: use blk_rq_map_kern
memstick: don't allow REQ_TYPE_BLOCK_PC requests
block: shrink bio size again
block: simplify and cleanup bvec pool handling
block: get rid of bio_rw and READA
block: don't ignore -EOPNOTSUPP blkdev_issue_write_same
block: introduce BLKDEV_DISCARD_ZERO to fix zeroout
NVMe: don't allocate unused nvme_major
nvme: avoid crashes when node 0 is memoryless node.
nvme: Limit command retries
loop: Make user notify for adding loop device failed
nvme-loop: fix nvme-loop Kconfig dependencies
nvmet: fix return value check in nvmet_subsys_alloc()
...
21 Jul, 2016
2 commits
-
For a front merge, the maximum number of sectors of the
request must be checked against the front merge BIO sector,
not the current sector of the request.Signed-off-by: Damien Le Moal
Reviewed-by: Hannes Reinecke
Signed-off-by: Jens Axboe -
Before merging a bio into an existing request, io scheduler is called to
get its approval first. However, the requests that come from a plug
flush may get merged by block layer without consulting with io
scheduler.In case of CFQ, this can cause fairness problems. For instance, if a
request gets merged into a low weight cgroup's request, high weight cgroup
now will depend on low weight cgroup to get scheduled. If high weigt cgroup
needs that io request to complete before submitting more requests, then it
will also lose its timeslice.Following script demonstrates the problem. Group g1 has a low weight, g2
and g3 have equal high weights but g2's requests are adjacent to g1's
requests so they are subject to merging. Due to these merges, g2 gets
poor disk time allocation.cat > cfq-merge-repro.sh << "EOF"
#!/bin/bash
set -eIO_ROOT=/mnt-cgroup/io
mkdir -p $IO_ROOT
if ! mount | grep -qw $IO_ROOT; then
mount -t cgroup none -oblkio $IO_ROOT
ficd $IO_ROOT
for i in g1 g2 g3; do
if [ -d $i ]; then
rmdir $i
fi
donemkdir g1 && echo 10 > g1/blkio.weight
mkdir g2 && echo 495 > g2/blkio.weight
mkdir g3 && echo 495 > g3/blkio.weightRUNTIME=10
(echo $BASHPID > g1/cgroup.procs &&
fio --readonly --name name1 --filename /dev/sdb \
--rw read --size 64k --bs 64k --time_based \
--runtime=$RUNTIME --offset=0k &> /dev/null)&(echo $BASHPID > g2/cgroup.procs &&
fio --readonly --name name1 --filename /dev/sdb \
--rw read --size 64k --bs 64k --time_based \
--runtime=$RUNTIME --offset=64k &> /dev/null)&(echo $BASHPID > g3/cgroup.procs &&
fio --readonly --name name1 --filename /dev/sdb \
--rw read --size 64k --bs 64k --time_based \
--runtime=$RUNTIME --offset=256k &> /dev/null)&sleep $((RUNTIME+1))
for i in g1 g2 g3; do
echo ---- $i ----
cat $i/blkio.time
doneEOF
# ./cfq-merge-repro.sh
---- g1 ----
8:16 162
---- g2 ----
8:16 165
---- g3 ----
8:16 686After applying the patch:
# ./cfq-merge-repro.sh
---- g1 ----
8:16 90
---- g2 ----
8:16 445
---- g3 ----
8:16 471Signed-off-by: Tahsin Erdogan
Signed-off-by: Jens Axboe
09 Jun, 2016
1 commit
-
Instead of overloading the discard support with the REQ_SECURE flag.
Use the opportunity to rename the queue flag as well, and remove the
dead checks for this flag in the RAID 1 and RAID 10 drivers that don't
claim support for secure erase.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
08 Jun, 2016
3 commits
-
This patch converts the block layer merging code to use separate variables
for the operation and flags, and to check req_op for the REQ_OP.Signed-off-by: Mike Christie
Reviewed-by: Christoph Hellwig
Reviewed-by: Hannes Reinecke
Signed-off-by: Jens Axboe -
This patch converts the simple bi_rw use cases in the block,
drivers, mm and fs code to set/get the bio operation using
bio_set_op_attrs/bio_opThese should be simple one or two liner cases, so I just did them
in one patch. The next patches handle the more complicated
cases in a module per patch.Signed-off-by: Mike Christie
Reviewed-by: Hannes Reinecke
Signed-off-by: Jens Axboe -
We currently set REQ_WRITE/WRITE for all non READ IOs
like discard, flush, writesame, etc. In the next patches where we
no longer set up the op as a bitmap, we will not be able to
detect a operation direction like writesame by testing if REQ_WRITE is
set.This patch converts the drivers and cgroup to use the
op_is_write helper. This should just cover the simple
cases. I did dm, md and bcache in their own patches
because they were more involved.Signed-off-by: Mike Christie
Reviewed-by: Hannes Reinecke
Signed-off-by: Jens Axboe
