This patch adds the following:
1) Compiler hinting in the fast path.
2) A prefetch of port->flags to eliminate moderate cpu stalling later
in mtip_hw_submit_io().
3) Eliminate a redundant rq_data_dir().
4) Reorder members of driver_data to eliminate false cacheline sharing
between irq_workers_active and unal_qdepth.
With some workload and topology configurations, I'm seeing ~1.5%
throughput improvement in small block random read benchmarks as well
as improved latency std. dev.
Signed-off-by: Sam Bradshaw <sbradshaw@micron.com>
Add include of <linux/prefetch.h>
Signed-off-by: Jens Axboe <axboe@fb.com>
With the optimizations around not clearing the full request at alloc
time, we are leaving some of the needed init for REQ_TYPE_BLOCK_PC
up to the user allocating the request.
Add a blk_rq_set_block_pc() that sets the command type to
REQ_TYPE_BLOCK_PC, and properly initializes the members associated
with this type of request. Update callers to use this function instead
of manipulating rq->cmd_type directly.
Includes fixes from Christoph Hellwig <hch@lst.de> for my half-assed
attempt.
Signed-off-by: Jens Axboe <axboe@fb.com>
Merge misc updates from Andrew Morton:
- a few fixes for 3.16. Cc'ed to stable so they'll get there somehow.
- various misc fixes and cleanups
- most of the ocfs2 queue. Review is slow...
- most of MM. The MM queue is pretty huge this time, but not much in
the way of feature work.
- some tweaks under kernel/
- printk maintenance work
- updates to lib/
- checkpatch updates
- tweaks to init/
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (276 commits)
fs/autofs4/dev-ioctl.c: add __init to autofs_dev_ioctl_init
fs/ncpfs/getopt.c: replace simple_strtoul by kstrtoul
init/main.c: remove an ifdef
kthreads: kill CLONE_KERNEL, change kernel_thread(kernel_init) to avoid CLONE_SIGHAND
init/main.c: add initcall_blacklist kernel parameter
init/main.c: don't use pr_debug()
fs/binfmt_flat.c: make old_reloc() static
fs/binfmt_elf.c: fix bool assignements
fs/efs: convert printk(KERN_DEBUG to pr_debug
fs/efs: add pr_fmt / use __func__
fs/efs: convert printk to pr_foo()
scripts/checkpatch.pl: device_initcall is not the only __initcall substitute
checkpatch: check stable email address
checkpatch: warn on unnecessary void function return statements
checkpatch: prefer kstrto<foo> to sscanf(buf, "%<lhuidx>", &bar);
checkpatch: add warning for kmalloc/kzalloc with multiply
checkpatch: warn on #defines ending in semicolon
checkpatch: make --strict a default for files in drivers/net and net/
checkpatch: always warn on missing blank line after variable declaration block
checkpatch: fix wildcard DT compatible string checking
...
We want to skip the physical block(PAGE_SIZE) which is partially covered
by the discard bio, so we check the remaining size and subtract it if
there is a need to goto the next physical block.
The current offset usage in zram_bio_discard is incorrect, it will cause
its upper filesystem breakdown. Consider the following scenario:
On some architecture or config, PAGE_SIZE is 64K for example, filesystem
is set up on zram disk without PAGE_SIZE aligned, a discard bio leads to a
offset = 4K and size=72K, normally, it should not really discard any
physical block as it partially cover two physical blocks. However, with
the current offset usage, it will discard the second physical block and
free its memory, which will cause filesystem breakdown.
This patch corrects the offset usage in zram_bio_discard.
Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
brd is effectively a thinly provisioned device. Thinly provisioned
devices return -ENOSPC when they can't write a new block. -ENOMEM is an
implementation detail that callers shouldn't know.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Acked-by: Dave Chinner <david@fromorbit.com>
Cc: Dheeraj Reddy <dheeraj.reddy@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We currently pass in the hardware queue, and get the tags from there.
But from scsi-mq, with a shared tag space, it's a lot more convenient
to pass in the blk_mq_tags instead as the hardware queue isn't always
directly available. So instead of having to re-map to a given
hardware queue from rq->mq_ctx, just pass in the tags structure.
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull scheduler updates from Ingo Molnar:
"The main scheduling related changes in this cycle were:
- various sched/numa updates, for better performance
- tree wide cleanup of open coded nice levels
- nohz fix related to rq->nr_running use
- cpuidle changes and continued consolidation to improve the
kernel/sched/idle.c high level idle scheduling logic. As part of
this effort I pulled cpuidle driver changes from Rafael as well.
- standardized idle polling amongst architectures
- continued work on preparing better power/energy aware scheduling
- sched/rt updates
- misc fixlets and cleanups"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (49 commits)
sched/numa: Decay ->wakee_flips instead of zeroing
sched/numa: Update migrate_improves/degrades_locality()
sched/numa: Allow task switch if load imbalance improves
sched/rt: Fix 'struct sched_dl_entity' and dl_task_time() comments, to match the current upstream code
sched: Consolidate open coded implementations of nice level frobbing into nice_to_rlimit() and rlimit_to_nice()
sched: Initialize rq->age_stamp on processor start
sched, nohz: Change rq->nr_running to always use wrappers
sched: Fix the rq->next_balance logic in rebalance_domains() and idle_balance()
sched: Use clamp() and clamp_val() to make sys_nice() more readable
sched: Do not zero sg->cpumask and sg->sgp->power in build_sched_groups()
sched/numa: Fix initialization of sched_domain_topology for NUMA
sched: Call select_idle_sibling() when not affine_sd
sched: Simplify return logic in sched_read_attr()
sched: Simplify return logic in sched_copy_attr()
sched: Fix exec_start/task_hot on migrated tasks
arm64: Remove TIF_POLLING_NRFLAG
metag: Remove TIF_POLLING_NRFLAG
sched/idle: Make cpuidle_idle_call() void
sched/idle: Reflow cpuidle_idle_call()
sched/idle: Delay clearing the polling bit
...
Pull block driver changes from Jens Axboe:
"Now that the core bits are in, here's the pull request for the driver
related changes for 3.16. Nothing out of the ordinary here, mostly
business as usual. There are a few pulls of for-3.16/core into this
branch, which were done when the blk-mq was modified after the
mtip32xx conversion was put in.
The pull request contains:
- skd and cciss converted to use pci_enable_msix_exact(). From
Alexander Gordeev.
- A few mtip32xx fixes from Asai @ Micron.
- The conversion of mtip32xx from make_request_fn to blk-mq, and a
later small fix for that conversion on quiescing for non-queued IO.
From me.
- A fix for bsg to use an exported function to check whether this
driver is request based or not. Needed updating for blk-mq, which
is request based, but does not have a request_fn hook. From me.
- Small floppy bug fix from Jiri.
- A series of cleanups for the cdrom uniform layer from Joe Perches.
Gets rid of various old ugly macros, making the code conform more
to the modern coding style.
- A series of patches for drbd from the drbd crew (Lars Ellenberg and
Philipp Reisner).
- A use-after-free fix for null_blk from Ming Lei.
- Also from Ming Lei is a performance patch for virtio-blk, which can
net us a 3x win on kvm platforms where world notification is
expensive.
- Ming Lei also fixed a stall issue in virtio-blk, due to a race
between queue start/stop and resource limits.
- A small batch of fixes for xen-blk{back,front} from Olaf Hering and
Valentin Priescu"
* 'for-3.16/drivers' of git://git.kernel.dk/linux-block: (54 commits)
block: virtio_blk: don't hold spin lock during world switch
xen-blkback: defer freeing blkif to avoid blocking xenwatch
xen blkif.h: fix comment typo in discard-alignment
xen/blkback: disable discard feature if requested by toolstack
xen-blkfront: remove type check from blkfront_setup_discard
floppy: do not corrupt bio.bi_flags when reading block 0
mtip32xx: move error handling to service thread
virtio_blk: fix race between start and stop queue
mtip32xx: stop block hardware queues before quiescing IO
mtip32xx: blk_mq_init_queue() returns an ERR_PTR
mtip32xx: convert to use blk-mq
cdrom: Remove unnecessary prototype for cdrom_get_disc_info
cdrom: Remove unnecessary prototype for cdrom_mrw_exit
cdrom: Remove cdrom_count_tracks prototype
cdrom: Remove cdrom_get_next_writeable prototype
cdrom: Remove cdrom_get_last_written prototype
cdrom: Move mmc_ioctls above cdrom_ioctl to remove unnecessary prototype
cdrom: Remove unnecessary sanitize_format prototype
cdrom: Remove unnecessary check_for_audio_disc prototype
cdrom: Remove prototype for open_for_data
...
Pull block core updates from Jens Axboe:
"It's a big(ish) round this time, lots of development effort has gone
into blk-mq in the last 3 months. Generally we're heading to where
3.16 will be a feature complete and performant blk-mq. scsi-mq is
progressing nicely and will hopefully be in 3.17. A nvme port is in
progress, and the Micron pci-e flash driver, mtip32xx, is converted
and will be sent in with the driver pull request for 3.16.
This pull request contains:
- Lots of prep and support patches for scsi-mq have been integrated.
All from Christoph.
- API and code cleanups for blk-mq from Christoph.
- Lots of good corner case and error handling cleanup fixes for
blk-mq from Ming Lei.
- A flew of blk-mq updates from me:
* Provide strict mappings so that the driver can rely on the CPU
to queue mapping. This enables optimizations in the driver.
* Provided a bitmap tagging instead of percpu_ida, which never
really worked well for blk-mq. percpu_ida relies on the fact
that we have a lot more tags available than we really need, it
fails miserably for cases where we exhaust (or are close to
exhausting) the tag space.
* Provide sane support for shared tag maps, as utilized by scsi-mq
* Various fixes for IO timeouts.
* API cleanups, and lots of perf tweaks and optimizations.
- Remove 'buffer' from struct request. This is ancient code, from
when requests were always virtually mapped. Kill it, to reclaim
some space in struct request. From me.
- Remove 'magic' from blk_plug. Since we store these on the stack
and since we've never caught any actual bugs with this, lets just
get rid of it. From me.
- Only call part_in_flight() once for IO completion, as includes two
atomic reads. Hopefully we'll get a better implementation soon, as
the part IO stats are now one of the more expensive parts of doing
IO on blk-mq. From me.
- File migration of block code from {mm,fs}/ to block/. This
includes bio.c, bio-integrity.c, bounce.c, and ioprio.c. From me,
from a discussion on lkml.
That should describe the meat of the pull request. Also has various
little fixes and cleanups from Dave Jones, Shaohua Li, Duan Jiong,
Fengguang Wu, Fabian Frederick, Randy Dunlap, Robert Elliott, and Sam
Bradshaw"
* 'for-3.16/core' of git://git.kernel.dk/linux-block: (100 commits)
blk-mq: push IPI or local end_io decision to __blk_mq_complete_request()
blk-mq: remember to start timeout handler for direct queue
block: ensure that the timer is always added
blk-mq: blk_mq_unregister_hctx() can be static
blk-mq: make the sysfs mq/ layout reflect current mappings
blk-mq: blk_mq_tag_to_rq should handle flush request
block: remove dead code in scsi_ioctl:blk_verify_command
blk-mq: request initialization optimizations
block: add queue flag for disabling SG merging
block: remove 'magic' from struct blk_plug
blk-mq: remove alloc_hctx and free_hctx methods
blk-mq: add file comments and update copyright notices
blk-mq: remove blk_mq_alloc_request_pinned
blk-mq: do not use blk_mq_alloc_request_pinned in blk_mq_map_request
blk-mq: remove blk_mq_wait_for_tags
blk-mq: initialize request in __blk_mq_alloc_request
blk-mq: merge blk_mq_alloc_reserved_request into blk_mq_alloc_request
blk-mq: add helper to insert requests from irq context
blk-mq: remove stale comment for blk_mq_complete_request()
blk-mq: allow non-softirq completions
...
Pull m68k updates from Geert Uytterhoeven:
"Highlights:
- support for running kernels in fast TT-RAM instead of slow ST-RAM
on Atari
- multi-platform EARLY_PRINTK
- better support for machines with lots of RAM (think ARAnyM), and
for running kernels larger than 4 MiB (think multi-platform)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
m68k/hp300: Convert printk to pr_foo()
m68k/apollo: Convert printk to pr_foo()
m68k/amiga: Convert printk(foo to pr_foo()
m68k: Increase initial mapping to 8 or 16 MiB if possible
m68k: Update defconfigs for v3.15-rc2
m68k/atari: fix SCC initialization for debug console
m68k/mvme16x: Adopt common boot console
m68k: Multi-platform EARLY_PRINTK
m68k: Toward platform agnostic framebuffer debug logging
m68k/atari - atari_scsi: use correct virt/phys translation for DMA buffer
m68k/atari - ataflop: use correct virt/phys translation for DMA buffer
m68k/atari - atafb: convert allocation of fb ram to new interface
m68k/atari - stram: alloc ST-RAM pool even if kernel not in ST-RAM
Firstly, it isn't necessary to hold lock of vblk->vq_lock
when notifying hypervisor about queued I/O.
Secondly, virtqueue_notify() will cause world switch and
it may take long time on some hypervisors(such as, qemu-arm),
so it isn't good to hold the lock and block other vCPUs.
On arm64 quad core VM(qemu-kvm), the patch can increase I/O
performance a lot with VIRTIO_RING_F_EVENT_IDX enabled:
- without the patch: 14K IOPS
- with the patch: 34K IOPS
fio script:
[global]
direct=1
bsrange=4k-4k
timeout=10
numjobs=4
ioengine=libaio
iodepth=64
filename=/dev/vdc
group_reporting=1
[f1]
rw=randread
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org # 3.13+
Signed-off-by: Jens Axboe <axboe@fb.com>
Konrad writes:
Please git pull the following branch:
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git stable/for-jens-3.16
which has a bunch of fixes to the Xen block frontend and backend driver
and a new parameter for Xen backend driver - an override (set by the toolstack)
whether to expose the discard support (if disk of course supports it) or not.
Currently xenwatch blocks in VBD disconnect, waiting for all pending I/O
requests to finish. If the VBD is attached to a hot-swappable disk, then
xenwatch can hang for a long period of time, stalling other watches.
INFO: task xenwatch:39 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
ffff880057f01bd0 0000000000000246 ffff880057f01ac0 ffffffff810b0782
ffff880057f01ad0 00000000000131c0 0000000000000004 ffff880057edb040
ffff8800344c6080 0000000000000000 ffff880058c00ba0 ffff880057edb040
Call Trace:
[<ffffffff810b0782>] ? irq_to_desc+0x12/0x20
[<ffffffff8128f761>] ? list_del+0x11/0x40
[<ffffffff8147a080>] ? wait_for_common+0x60/0x160
[<ffffffff8147bcef>] ? _raw_spin_lock_irqsave+0x2f/0x50
[<ffffffff8147bd49>] ? _raw_spin_unlock_irqrestore+0x19/0x20
[<ffffffff8147a26a>] schedule+0x3a/0x60
[<ffffffffa018fe6a>] xen_blkif_disconnect+0x8a/0x100 [xen_blkback]
[<ffffffff81079f70>] ? wake_up_bit+0x40/0x40
[<ffffffffa018ffce>] xen_blkbk_remove+0xae/0x1e0 [xen_blkback]
[<ffffffff8130b254>] xenbus_dev_remove+0x44/0x90
[<ffffffff81345cb7>] __device_release_driver+0x77/0xd0
[<ffffffff81346488>] device_release_driver+0x28/0x40
[<ffffffff813456e8>] bus_remove_device+0x78/0xe0
[<ffffffff81342c9f>] device_del+0x12f/0x1a0
[<ffffffff81342d2d>] device_unregister+0x1d/0x60
[<ffffffffa0190826>] frontend_changed+0xa6/0x4d0 [xen_blkback]
[<ffffffffa019c252>] ? frontend_changed+0x192/0x650 [xen_netback]
[<ffffffff8130ae50>] ? cmp_dev+0x60/0x60
[<ffffffff81344fe4>] ? bus_for_each_dev+0x94/0xa0
[<ffffffff8130b06e>] xenbus_otherend_changed+0xbe/0x120
[<ffffffff8130b4cb>] frontend_changed+0xb/0x10
[<ffffffff81309c82>] xenwatch_thread+0xf2/0x130
[<ffffffff81079f70>] ? wake_up_bit+0x40/0x40
[<ffffffff81309b90>] ? xenbus_directory+0x80/0x80
[<ffffffff810799d6>] kthread+0x96/0xa0
[<ffffffff81485934>] kernel_thread_helper+0x4/0x10
[<ffffffff814839f3>] ? int_ret_from_sys_call+0x7/0x1b
[<ffffffff8147c17c>] ? retint_restore_args+0x5/0x6
[<ffffffff81485930>] ? gs_change+0x13/0x13
With this patch, when there is still pending I/O, the actual disconnect
is done by the last reference holder (last pending I/O request). In this
case, xenwatch doesn't block indefinitely.
Signed-off-by: Valentin Priescu <priescuv@amazon.com>
Reviewed-by: Steven Kady <stevkady@amazon.com>
Reviewed-by: Steven Noonan <snoonan@amazon.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Newer toolstacks may provide a boolean property "discard-enable" in the
backend node. Its purpose is to disable discard for file backed storage
to avoid fragmentation. Recognize this setting also for physical
storage. If that property exists and is false, do not advertise
"feature-discard" to the frontend.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
In its initial implementation a check for "type" was added, but only phy
and file are handled. This breaks advertised discard support for other
type values such as qdisk.
Fix and simplify this function: If the backend advertises discard
support it is supposed to implement it properly, so enable
feature_discard unconditionally. If the backend advertises the need for
a certain granularity and alignment then propagate both properties to
the blocklayer. The discard-secure property is a boolean, update the code
to reflect that.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Pull in core changes (again), since we got rid of the alloc/free
hctx mq_ops hooks and mtip32xx then needed updating again.
Signed-off-by: Jens Axboe <axboe@fb.com>
There is no need for drivers to control hardware context allocation
now that we do the context to node mapping in common code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
mtip32xx uses blk_mq_alloc_reserved_request(), so pull in the
core changes so we have a properly merged end result.
Signed-off-by: Jens Axboe <axboe@fb.com>
Commit 41a55b4de3 ("floppy: silence warning during disk test") caused
bio.bi_flags being overwritten, and its initialization to BIO_UPTODATE
in bio_init() to be lost.
This was unnoticed until 7b7b68bba5 ("floppy: bail out in open() if
drive is not responding to block0 read"), because the error value wasn't
checked for in the bio completion callback.
Now we are actually looking at the error, and the loss of BIO_UPTODATE
causes EIO to be wrongly passed to the callback, which confuses the
FD_OPEN_SHOULD_FAIL_BIT logic.
Fix this by not destroying previous value of bi_flags when setting
BIO_QUIET.
Cc: Stephen Hemminger <shemminger@vyatta.com>
Reported-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Drivers currently have to figure this out on their own, and they
are missing information to do it properly. The ones that did
attempt to do it, do it wrong.
So just pass in the suggested node directly to the alloc
function.
Signed-off-by: Jens Axboe <axboe@fb.com>
Quiesce and shutdown the device prior to reset, then restart the device and
resume IO after.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
When there isn't enough vring descriptor for adding to vq,
blk-mq will be put as stopped state until some of pending
descriptors are completed & freed.
Unfortunately, the vq's interrupt may come just before
blk-mq's BLK_MQ_S_STOPPED flag is set, so the blk-mq will
still be kept as stopped even though lots of descriptors
are completed and freed in the interrupt handler. The worst
case is that all pending descriptors are freed in the
interrupt handler, and the queue is kept as stopped forever.
This patch fixes the problem by starting/stopping blk-mq
with holding vq_lock.
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
Conflicts:
drivers/block/virtio_blk.c
With the kernel running from FastRAM instead of ST-RAM, none of ST-RAM is
mapped by mem_init, and DMA-addressable buffer must be mapped by ioremap.
Use platform specific virt/phys translation helpers for this case.
Signed-off-by: Michael Schmitz <schmitz@debian.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Move error handling to service thread, and use mtip_set_timeout()
to set timeouts for HDIO_DRIVE_TASK and HDIO_DRIVE_CMD IOCTL commands.
Signed-off-by: Selvan Mani <smani@micron.com>
Signed-off-by: Asai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
When there isn't enough vring descriptor for adding to vq,
blk-mq will be put as stopped state until some of pending
descriptors are completed & freed.
Unfortunately, the vq's interrupt may come just before
blk-mq's BLK_MQ_S_STOPPED flag is set, so the blk-mq will
still be kept as stopped even though lots of descriptors
are completed and freed in the interrupt handler. The worst
case is that all pending descriptors are freed in the
interrupt handler, and the queue is kept as stopped forever.
This patch fixes the problem by starting/stopping blk-mq
with holding vq_lock.
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
We need to stop the block layer queues to prevent new "normal"
IO from entering the driver, while we wait for existing commands
to finish.
Signed-off-by: Jens Axboe <axboe@fb.com>
We changed this from blk_alloc_queue_node() to blk_mq_init_queue() so
the check needs to be updated as well.
Fixes: ffc771b3ca ('mtip32xx: convert to use blk-mq')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This rips out timeout handling, requeueing, etc in converting
it to use blk-mq instead.
Acked-by: Asai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Do not leak kernel-only floppy_raw_cmd structure members to userspace.
This includes the linked-list pointer and the pointer to the allocated
DMA space.
Signed-off-by: Matthew Daley <mattd@bugfuzz.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Always clear out these floppy_raw_cmd struct members after copying the
entire structure from userspace so that the in-kernel version is always
valid and never left in an interdeterminate state.
Signed-off-by: Matthew Daley <mattd@bugfuzz.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
entry(cmd->ll_list) may belong to new request once end_cmd()
returns, so fix the bug with the patch.
Without the change, it is easy to observe oops when
doing null_blk(timer) test.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
If there are no peer_devices or connections, I'd rather have NULL
than some "arbitrary" address pretending to point to a struct.
Helps to avoid hard to debug symptoms, in case we ever try to use
and dereference a drbd_connection or drbd_peer_device
where we in fact don't have any connection at all.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
A newly created device was never exposed before, i.e. has a
exposed_data_uuid of 0. Then it is valid to attach to any current_uuid
of a backing device (of course also to a newly created one (4))
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
In case a connection transitions into C_TIMEOUT within the timer
function (request_timer_fn()) we need to make sure that the receiver
thread (potentially running on a different CPU) sees the updated
cstate later on.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Just because it is the oldest not yet completed request
does not make it the oldest request waiting for disk.
Or waiting for the peer.
And we completely missed already completed requests
that would still hold references to activity log extents,
waiting only for the barrier ack.
Find two oldest not yet completely processed requests,
one that is still waiting for local completion,
and one that is still waiting for some response from the peer.
These may or may not be the same request object.
Then separately apply the network and disk timeouts, respectively.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
In the implementation as it was, the two peers sent each other
a challenge, and expects the challenge hashed with the shared
secret back.
A attacker could simply wait for the challenge of the peer, and
send the same challenge back. Then it waits for the response, and
sends the same response back.
Prevent this by not accepting a challenge from the peer that is
the same as the challenge sent to the peer.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Once our sender thread needs to wait_for_work(),
and actually needs to schedule(), just before we do that,
we already check if it is useful to implicitly close the last epoch.
The condition was too strict: only implicitly close the epoch,
if there have been no new (write) requests at all.
The assumption was that if there were new requests, they would
always be communicated one way or another, and would send necessary
epoch separating barriers explicitly.
This is not always true, e.g. when becoming diskless,
or while explicitly starting a full resync.
The last communicated epoch could stay open for a long time,
locking down corresponding activity log extents.
It is safe to always implicitly send that last barrier, as soon as we
determin that there cannot be more requests in the last communicated
epoch, even if there have been (uncommunicated) new requests in new
epochs meanwhile.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
When batching more updates to the activity log into single transactions,
we lost the ability for new requests to force themselves into the active
set: all preparation steps became non-blocking, and if all currently
hot extents keep busy, they could starve out new incoming requests
to cold extents for quite a while.
This can only happen if your IO backend accepts more IO operations per
average DRBD replication round trip time than you have al-extents
configured.
If we have incoming requests to cold extents,
at least do one blocking update per transaction.
In an artificial worst-case workload on SSD with an asynchronous 600 ms
replication link, with al-extents = 7 (the minimum we allow), and
concurrent full resynch, without this patch, some write requests have
been observed to be starved for 40 seconds.
With this patch, application observed a worst case latency of twice the
replication round trip time.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
We want to store in persistent meta data what the peer DRBD can handle,
which, due to spreading requests to multiple bios,
may be more than its backing device can handle.
Otherwise, if a disconnected Primary temporarily loses access to its local data
as well, we may accidentally shrink the max-bio setting, portentially causing
already assembled, but not yet processed, application bios to be spuriously
failed due to device limits.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
In the drbd make request function, specifically in
drbd_send_and_submit(), we decide whether we want to send the actual
write request, or only a "set this block out of sync" information.
We do so based on the current connection state, while holding the req_lock.
The connection state is not supposed to change while holding the req_lock.
But in drbd_start_resync, we did change that state anyways,
while only holding the global_state_lock, which is enough to change
sync-after dependencies (paused vs active resync), but
not good enough to change the connection state.
Fix: in drbd_start_resync, first grab the req_lock to serialize with
drbd_send_and_submit(), before grabbing the global_state_lock
to be able to evaluate the sync-after dependencies.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Allow the user of REQ_DISCARD.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Note that I do NOT call __drbd_chk_io_error for failed REQ_DISCARD.
That may be wrong, though, or needs to differ between EOPNOTSUPP and
other errors...
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
If the receiver needs to serve a discard request on a queue that does
not announce to be discard cabable, it falls back to do synchronous
blkdev_issue_zeroout().
We expect only "reasonably" large (up to one activity log extent?)
discard requests.
We do this to not to not block the receiver for too long in this
fallback code path, and to not set/clear too many bits inside one
spinlock_irq_save() in drbd_set_in_sync/drbd_set_out_of_sync,
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
We plan to use genl_family->parallel_ops = true in the future,
but need to review all possible interactions first.
For now, only selectively drop genl_lock() in drbd_set_role(),
instead serializing on our own internal resource->conf_update mutex.
We now can be promoted/demoted on many resources in parallel,
which may significantly improve cluster failover times
when fencing is required.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
