Pull block driver changes from Jens Axboe:
"This contains:
- The 4k/partition fixes for brd from Boaz/Matthew.
- A few xen front/back block fixes from David Vrabel and Roger Pau
Monne.
- Floppy changes from Takashi, cleaning the device file creation.
- Switching libata to use the new blk-mq tagging policy, removing
code (and a suboptimal implementation) from libata. This will
throw you a merge conflict, since a bug in the original libata
tagging code was fixed since this code was branched. Trivial.
From Shaohua.
- Conversion of loop to blk-mq, from Ming Lei.
- Cleanup of the io_schedule() handling in bsg from Peter Zijlstra.
He claims it improves on unreadable code, which will cost him a
beer.
- Maintainer update or NDB, now handled by Markus Pargmann.
- NVMe:
- Optimization from me that avoids a kmalloc/kfree per IO for
smaller (<= 8KB) IO. This cuts about 1% of high IOPS CPU
overhead.
- Removal of (now) dead RCU code, a relic from before NVMe was
converted to blk-mq"
* 'for-3.20/drivers' of git://git.kernel.dk/linux-block:
xen-blkback: default to X86_32 ABI on x86
xen-blkfront: fix accounting of reqs when migrating
xen-blkback,xen-blkfront: add myself as maintainer
block: Simplify bsg complete all
floppy: Avoid manual call of device_create_file()
NVMe: avoid kmalloc/kfree for smaller IO
MAINTAINERS: Update NBD maintainer
libata: make sata_sil24 use fifo tag allocator
libata: move sas ata tag allocation to libata-scsi.c
libata: use blk taging
NVMe: within nvme_free_queues(), delete RCU sychro/deferred free
null_blk: suppress invalid partition info
brd: Request from fdisk 4k alignment
brd: Fix all partitions BUGs
axonram: Fix bug in direct_access
loop: add blk-mq.h include
block: loop: don't handle REQ_FUA explicitly
block: loop: introduce lo_discard() and lo_req_flush()
block: loop: say goodby to bio
block: loop: improve performance via blk-mq
Pull core block IO changes from Jens Axboe:
"This contains:
- A series from Christoph that cleans up and refactors various parts
of the REQ_BLOCK_PC handling. Contributions in that series from
Dongsu Park and Kent Overstreet as well.
- CFQ:
- A bug fix for cfq for realtime IO scheduling from Jeff Moyer.
- A stable patch fixing a potential crash in CFQ in OOM
situations. From Konstantin Khlebnikov.
- blk-mq:
- Add support for tag allocation policies, from Shaohua. This is
a prep patch enabling libata (and other SCSI parts) to use the
blk-mq tagging, instead of rolling their own.
- Various little tweaks from Keith and Mike, in preparation for
DM blk-mq support.
- Minor little fixes or tweaks from me.
- A double free error fix from Tony Battersby.
- The partition 4k issue fixes from Matthew and Boaz.
- Add support for zero+unprovision for blkdev_issue_zeroout() from
Martin"
* 'for-3.20/core' of git://git.kernel.dk/linux-block: (27 commits)
block: remove unused function blk_bio_map_sg
block: handle the null_mapped flag correctly in blk_rq_map_user_iov
blk-mq: fix double-free in error path
block: prevent request-to-request merging with gaps if not allowed
blk-mq: make blk_mq_run_queues() static
dm: fix multipath regression due to initializing wrong request
cfq-iosched: handle failure of cfq group allocation
block: Quiesce zeroout wrapper
block: rewrite and split __bio_copy_iov()
block: merge __bio_map_user_iov into bio_map_user_iov
block: merge __bio_map_kern into bio_map_kern
block: pass iov_iter to the BLOCK_PC mapping functions
block: add a helper to free bio bounce buffer pages
block: use blk_rq_map_user_iov to implement blk_rq_map_user
block: simplify bio_map_kern
block: mark blk-mq devices as stackable
block: keep established cmd_flags when cloning into a blk-mq request
block: add blk-mq support to blk_insert_cloned_request()
block: require blk_rq_prep_clone() be given an initialized clone request
blk-mq: add tag allocation policy
...
Pull backing device changes from Jens Axboe:
"This contains a cleanup of how the backing device is handled, in
preparation for a rework of the life time rules. In this part, the
most important change is to split the unrelated nommu mmap flags from
it, but also removing a backing_dev_info pointer from the
address_space (and inode), and a cleanup of other various minor bits.
Christoph did all the work here, I just fixed an oops with pages that
have a swap backing. Arnd fixed a missing export, and Oleg killed the
lustre backing_dev_info from staging. Last patch was from Al,
unexporting parts that are now no longer needed outside"
* 'for-3.20/bdi' of git://git.kernel.dk/linux-block:
Make super_blocks and sb_lock static
mtd: export new mtd_mmap_capabilities
fs: make inode_to_bdi() handle NULL inode
staging/lustre/llite: get rid of backing_dev_info
fs: remove default_backing_dev_info
fs: don't reassign dirty inodes to default_backing_dev_info
nfs: don't call bdi_unregister
ceph: remove call to bdi_unregister
fs: remove mapping->backing_dev_info
fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info
nilfs2: set up s_bdi like the generic mount_bdev code
block_dev: get bdev inode bdi directly from the block device
block_dev: only write bdev inode on close
fs: introduce f_op->mmap_capabilities for nommu mmap support
fs: kill BDI_CAP_SWAP_BACKED
fs: deduplicate noop_backing_dev_info
The tape drivers (and the sg driver in a special case that doesn't matter
here) use the null_mapped flag to tell blk_rq_map_user to not copy around
any data into or out of the bounce buffers. blk_rq_map_user_iov never
got that treatment, which didn't matter until I refactored blk_rq_map_user
to be implemented in terms of blk_rq_map_user_iov.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Fixes: ddad8dd0a1 ("block: use blk_rq_map_user_iov to implement blk_rq_map_user")
Signed-off-by: Jens Axboe <axboe@fb.com>
If the allocation of bt->bs fails, then bt->map can be freed twice, once
in blk_mq_init_bitmap_tags() -> bt_alloc(), and once in
blk_mq_init_bitmap_tags() -> bt_free(). Fix by setting the pointer to
NULL after the first free.
Cc: <stable@vger.kernel.org>
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
If the queue has SG_GAPS set, we must not merge across an sg gap.
This is caught for the bio case, but currently not for the
more rare case of merging two requests directly.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Cut the dm bits, those will go through the dm tree, and fixed
the test_bit() test.
Signed-off-by: Jens Axboe <axboe@fb.com>
We no longer use it outside of blk-mq.c, so we can make it static
and stop exporting it. Additionally, kill the 'async' argument, as
there's only one used of it.
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull EFI updates from Ingo Molnar:
"Main changes:
- Move efivarfs from the misc filesystem section to pseudo filesystem
- Expose firmware platform size in sysfs
- Improve robustness of get_memory_map() by removing assumptions on
the size of efi_memory_desc_t.
- various cleanups and fixes
The biggest risk is the get_memory_map() change, which changes the way
that both the arm64 and x86 EFI boot stub build the early memory map.
There are no known regressions with it at the moment, BYMMV"
* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi: Don't look for chosen@0 node on DT platforms
firmware: efi: Remove unneeded guid unparse
efi/libstub: Call get_memory_map() to obtain map and desc sizes
efi: Small leak on error in runtime map code
efi: rtc-efi: Mark UIE as unsupported
arm64/efi: efistub: Apply __init annotation
efi: Expose underlying UEFI firmware platform size to userland
efi: Rename efi_guid_unparse to efi_guid_to_str
efi: Update the URLs for efibootmgr
fs: Make efivarfs a pseudo filesystem, built by default with EFI
Cfq_lookup_create_cfqg() allocates struct blkcg_gq using GFP_ATOMIC.
In cfq_find_alloc_queue() possible allocation failure is not handled.
As a result kernel oopses on NULL pointer dereference when
cfq_link_cfqq_cfqg() calls cfqg_get() for NULL pointer.
Bug was introduced in v3.5 in commit cd1604fab4 ("blkcg: factor
out blkio_group creation"). Prior to that commit cfq group lookup
had returned pointer to root group as fallback.
This patch handles this error using existing fallback oom_cfqq.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Fixes: cd1604fab4 ("blkcg: factor out blkio_group creation")
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
blkdev_issue_zeroout() printed a warning if a device failed a discard or
write same request despite advertising support for these. That's fine
for SCSI since we'll disable these commands if we get an error back from
the disk saying that they are not supported. And consequently the
warning only gets printed once.
There are other types of block devices that support discard, however,
and these may return -EOPNOTSUPP for each command but leave discard
enabled in the queue limits. This will cause a warning message for every
blkdev_issue_zeroout() invocation.
Remove the offending warning messages.
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Rewrite __bio_copy_iov using the copy_page_{from,to}_iter helpers, and
split it into two simpler functions.
This commit should contain only literal replacements, without
functional changes.
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dongsu Park <dongsu.park@profitbricks.com>
[hch: removed the __bio_copy_iov wrapper]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
And also remove the unused bdev argument.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This saves a little code, and allow to simplify the error handling.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Make use of a new interface provided by iov_iter, backed by
scatter-gather list of iovec, instead of the old interface based on
sg_iovec. Also use iov_iter_advance() instead of manual iteration.
This commit should contain only literal replacements, without
functional changes.
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
[dpark: add more description in commit message]
Signed-off-by: Dongsu Park <dongsu.park@profitbricks.com>
[hch: fixed to do a deep clone of the iov_iter, and to properly use
the iov_iter direction]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The code sniplet to walk all bio_vecs and free their pages is opencoded in
way to many places, so factor it into a helper. Also convert the slightly
more complex cases in bio_kern_endio and __bio_copy_iov where we break
the freeing from an existing loop into a separate one.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Just open code the trivial mapping from a kernel virtual address to
a bio instead of going through the complex user address mapping
machinery.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
It took me a few tries to figure out what this code did; lets rewrite
it into a more regular form.
The thing that makes this one 'special' is the BSG_F_BLOCK flag, if
that is not set we're not supposed/allowed to block and should spin
wait for completion.
The (new) io_wait_event() will never see a false condition in case of
the spinning and we will therefore not block.
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
since that's a more logical and accurate place - Leif Lindholm
* Update efibootmgr URL in Kconfig help - Peter Jones
* Improve accuracy of EFI guid function names - Borislav Petkov
* Expose firmware platform size in sysfs for the benefit of EFI boot
loader installers and other utilities - Steve McIntyre
* Cleanup __init annotations for arm64/efi code - Ard Biesheuvel
* Mark the UIE as unsupported for rtc-efi - Ard Biesheuvel
* Fix memory leak in error code path of runtime map code - Dan Carpenter
* Improve robustness of get_memory_map() by removing assumptions on the
size of efi_memory_desc_t (which could change in future spec
versions) and querying the firmware instead of guessing about the
memmap size - Ard Biesheuvel
* Remove superfluous guid unparse calls - Ivan Khoronzhuk
* Delete unnecessary chosen@0 DT node FDT code since was duplicated
from code in drivers/of and is entirely unnecessary - Leif Lindholm
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Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/efi
Pull EFI updates from Matt Fleming:
" - Move efivarfs from the misc filesystem section to pseudo filesystem,
since that's a more logical and accurate place - Leif Lindholm
- Update efibootmgr URL in Kconfig help - Peter Jones
- Improve accuracy of EFI guid function names - Borislav Petkov
- Expose firmware platform size in sysfs for the benefit of EFI boot
loader installers and other utilities - Steve McIntyre
- Cleanup __init annotations for arm64/efi code - Ard Biesheuvel
- Mark the UIE as unsupported for rtc-efi - Ard Biesheuvel
- Fix memory leak in error code path of runtime map code - Dan Carpenter
- Improve robustness of get_memory_map() by removing assumptions on the
size of efi_memory_desc_t (which could change in future spec
versions) and querying the firmware instead of guessing about the
memmap size - Ard Biesheuvel
- Remove superfluous guid unparse calls - Ivan Khoronzhuk
- Delete unnecessary chosen@0 DT node FDT code since was duplicated
from code in drivers/of and is entirely unnecessary - Leif Lindholm
There's nothing super scary, mainly cleanups, and a merge from Ricardo who
kindly picked up some patches from the linux-efi mailing list while I
was out on annual leave in December.
Perhaps the biggest risk is the get_memory_map() change from Ard, which
changes the way that both the arm64 and x86 EFI boot stub build the
early memory map. It would be good to have it bake in linux-next for a
while.
"
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The kobject memory inside blk-mq hctx/ctx shouldn't have been freed
before the kobject is released because driver core can access it freely
before its release.
We can't do that in all ctx/hctx/mq_kobj's release handler because
it can be run before blk_cleanup_queue().
Given mq_kobj shouldn't have been introduced, this patch simply moves
mq's release into blk_release_queue().
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This reverts commit 76d697d107.
The commit 76d697d107 causes general protection fault
reported from Bart Van Assche:
https://lkml.org/lkml/2015/1/28/334
Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
blk_mq_alloc_request() may establish REQ_MQ_INFLIGHT in addition to
incrementing the hctx->nr_active count. Any cmd_flags that are
established in the newly allocated clone request must be preserved in
addition to the cmd_flags that are later copied over from the original
request as part of blk_rq_prep_clone().
Otherwise, if REQ_MQ_INFLIGHT isn't set in the clone request the
hctx->nr_active count won't get decremented via blk_mq_free_request().
The only consumer of blk_rq_prep_clone() is request-based DM, which uses
blk_rq_init() prior to calling blk_rq_prep_clone() for the non-blk-mq
case. Given the cloned request's cmd_flags will be 0 it is safe to OR
them with the original request's cmd_flags for both the non-blk-mq and
blk-mq cases.
Reported-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
If the request passed to blk_insert_cloned_request() was allocated by
a blk-mq device it must be submitted using blk_mq_insert_request().
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Prepare to allow blk_rq_prep_clone() to accept clone requests that were
allocated from blk-mq request queues. As such the blk_rq_prep_clone()
caller must first initialize the clone request.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This is the blk-mq part to support tag allocation policy. The default
allocation policy isn't changed (though it's not a strict FIFO). The new
policy is round-robin for libata. But it's a try-best implementation. If
multiple tasks are competing, the tags returned will be mixed (which is
unavoidable even with !mq, as requests from different tasks can be
mixed in queue)
Cc: Jens Axboe <axboe@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The libata tag allocation is using a round-robin policy. Next patch will
make libata use block generic tag allocation, so let's add a policy to
tag allocation.
Currently two policies: FIFO (default) and round-robin.
Cc: Jens Axboe <axboe@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
As Christoph put it:
Can we just get rid of the warnings? It's fairly annoying as devices
without partitions are perfectly fine and very useful.
Me too I see this message every VM boot for ages on all my
devices. Would love to just remove it. For me a partition-table
is only needed for a booting BIOS, grub, and stuff.
CC: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Boaz Harrosh <boaz@plexistor.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
blkdev_issue_discard() will zero a given block range. This is done by
way of explicit writing, thus provisioning or allocating the blocks on
disk.
There are use cases where the desired behavior is to zero the blocks but
unprovision them if possible. The blocks must deterministically contain
zeroes when they are subsequently read back.
This patch adds a flag to blkdev_issue_zeroout() that provides this
variant. If the discard flag is set and a block device guarantees
discard_zeroes_data we will use REQ_DISCARD to clear the block range. If
the device does not support discard_zeroes_data or if the discard
request fails we will fall back to first REQ_WRITE_SAME and then a
regular REQ_WRITE.
Also update the callers of blkdev_issue_zero() to reflect the new flag
and make sb_issue_zeroout() prefer the discard approach.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Hi,
If you can manage to submit an async write as the first async I/O from
the context of a process with realtime scheduling priority, then a
cfq_queue is allocated, but filed into the wrong async_cfqq bucket. It
ends up in the best effort array, but actually has realtime I/O
scheduling priority set in cfqq->ioprio.
The reason is that cfq_get_queue assumes the default scheduling class and
priority when there is no information present (i.e. when the async cfqq
is created):
static struct cfq_queue *
cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic,
struct bio *bio, gfp_t gfp_mask)
{
const int ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio);
const int ioprio = IOPRIO_PRIO_DATA(cic->ioprio);
cic->ioprio starts out as 0, which is "invalid". So, class of 0
(IOPRIO_CLASS_NONE) is passed to cfq_async_queue_prio like so:
async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio);
static struct cfq_queue **
cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio)
{
switch (ioprio_class) {
case IOPRIO_CLASS_RT:
return &cfqd->async_cfqq[0][ioprio];
case IOPRIO_CLASS_NONE:
ioprio = IOPRIO_NORM;
/* fall through */
case IOPRIO_CLASS_BE:
return &cfqd->async_cfqq[1][ioprio];
case IOPRIO_CLASS_IDLE:
return &cfqd->async_idle_cfqq;
default:
BUG();
}
}
Here, instead of returning a class mapped from the process' scheduling
priority, we get back the bucket associated with IOPRIO_CLASS_BE.
Now, there is no queue allocated there yet, so we create it:
cfqq = cfq_find_alloc_queue(cfqd, is_sync, cic, bio, gfp_mask);
That function ends up doing this:
cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync);
cfq_init_prio_data(cfqq, cic);
cfq_init_cfqq marks the priority as having changed. Then, cfq_init_prio
data does this:
ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio);
switch (ioprio_class) {
default:
printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class);
case IOPRIO_CLASS_NONE:
/*
* no prio set, inherit CPU scheduling settings
*/
cfqq->ioprio = task_nice_ioprio(tsk);
cfqq->ioprio_class = task_nice_ioclass(tsk);
break;
So we basically have two code paths that treat IOPRIO_CLASS_NONE
differently, which results in an RT async cfqq filed into a best effort
bucket.
Attached is a patch which fixes the problem. I'm not sure how to make
it cleaner. Suggestions would be welcome.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Tested-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
Since "BDI: Provide backing device capability information [try #3]" the
backing_dev_info structure also provides flags for the kind of mmap
operation available in a nommu environment, which is entirely unrelated
to it's original purpose.
Introduce a new nommu-only file operation to provide this information to
the nommu mmap code instead. Splitting this from the backing_dev_info
structure allows to remove lots of backing_dev_info instance that aren't
otherwise needed, and entirely gets rid of the concept of providing a
backing_dev_info for a character device. It also removes the need for
the mtd_inodefs filesystem.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The kobject memory shouldn't have been freed before the kobject
is released because driver core can access it freely before its
release.
This patch frees hctx in its release callback. For ctx, they
share one single per-cpu variable which is associated with
the request queue, so free ctx in q->mq_kobj's release handler.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
(fix ctx kobjects)
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The blk-mq tagging tries to maintain some locality between CPUs and
the tags issued. The tags are split into groups of words, and the
words may not be fully populated. When searching for a new free tag,
blk-mq may look at partial words, hence it passes in an offset/size
to find_next_zero_bit(). However, it does that wrong, the size must
always be the full length of the number of tags in that word,
otherwise we'll potentially miss some near the end.
Another issue is when __bt_get() goes from one word set to the next.
It bumps the index, but not the last_tag associated with the
previous index. Bump that to be in the range of the new word.
Finally, clean up __bt_get() and __bt_get_word() a bit and get
rid of the goto in there, and the unnecessary 'wrap' variable.
Signed-off-by: Jens Axboe <axboe@fb.com>
Requests that haven't been started prior to a queue dying can be ended
in error without waiting for them to start and time out.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Added code comment to explain why this is done.
Signed-off-by: Jens Axboe <axboe@fb.com>
Some types of requests may be started that are not gauranteed to ever
complete. This adds a request flag that a driver can use so mark the
request as such.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Adds a helper function a driver can use to abort requeued requests in
case any are pending when h/w queues are being removed.
Signed-off-by: Jens Axboe <axboe@fb.com>
Kicking requeued requests will start h/w queues in a work_queue, which
may alter the driver's requested state to temporarily stop them. This
patch exports a method to cancel the q->requeue_work so a driver can be
assured stopped h/w queues won't be started up before it is ready.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Drivers can iterate over all allocated request tags, but their callback
needs a way to know if the driver started the request in the first place.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
When the queue is set to dying, wake up tasks that are waiting on frozen
queue so they realize it is dying and abandon their request.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Modified by me to add a code comment on the need for the wakeup.
Signed-off-by: Jens Axboe <axboe@fb.com>
Call it what it does - "unparse" is plain-misleading.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
We store it in the tag set, we don't need it in the hardware queue.
While removing cmd_size, place ->queue_num further down to avoid
a hole on 64-bit archs. It's not used in any fast paths, so we
can safely move it.
Signed-off-by: Jens Axboe <axboe@fb.com>
Commit b4c6a02877 exported the start and unfreeze, but we need
the regular blk_mq_freeze_queue() for the loop conversion.
Signed-off-by: Jens Axboe <axboe@fb.com>
If it's dying, we can't expect new request to complete and come
in an wake up other tasks waiting for requests. So after we
have marked it as dying, wake up everybody currently waiting
for a request. Once they wake, they will retry their allocation
and fail appropriately due to the state of the queue.
Tested-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This reverts commit 52f7eb945f.
The optimization is only really safe for a single queue, otherwise
'bs' and 'bt' can indeed change, and if we don't do a finish_wait()
for each loop, we'll potentially change the wait structure and
corrupt task wait list.
Reported-by: Jan Kara <jack@suse.cz>
Pull block driver core update from Jens Axboe:
"This is the pull request for the core block IO changes for 3.19. Not
a huge round this time, mostly lots of little good fixes:
- Fix a bug in sysfs blktrace interface causing a NULL pointer
dereference, when enabled/disabled through that API. From Arianna
Avanzini.
- Various updates/fixes/improvements for blk-mq:
- A set of updates from Bart, mostly fixing buts in the tag
handling.
- Cleanup/code consolidation from Christoph.
- Extend queue_rq API to be able to handle batching issues of IO
requests. NVMe will utilize this shortly. From me.
- A few tag and request handling updates from me.
- Cleanup of the preempt handling for running queues from Paolo.
- Prevent running of unmapped hardware queues from Ming Lei.
- Move the kdump memory limiting check to be in the correct
location, from Shaohua.
- Initialize all software queues at init time from Takashi. This
prevents a kobject warning when CPUs are brought online that
weren't online when a queue was registered.
- Single writeback fix for I_DIRTY clearing from Tejun. Queued with
the core IO changes, since it's just a single fix.
- Version X of the __bio_add_page() segment addition retry from
Maurizio. Hope the Xth time is the charm.
- Documentation fixup for IO scheduler merging from Jan.
- Introduce (and use) generic IO stat accounting helpers for non-rq
drivers, from Gu Zheng.
- Kill off artificial limiting of max sectors in a request from
Christoph"
* 'for-3.19/core' of git://git.kernel.dk/linux-block: (26 commits)
bio: modify __bio_add_page() to accept pages that don't start a new segment
blk-mq: Fix uninitialized kobject at CPU hotplugging
blktrace: don't let the sysfs interface remove trace from running list
blk-mq: Use all available hardware queues
blk-mq: Micro-optimize bt_get()
blk-mq: Fix a race between bt_clear_tag() and bt_get()
blk-mq: Avoid that __bt_get_word() wraps multiple times
blk-mq: Fix a use-after-free
blk-mq: prevent unmapped hw queue from being scheduled
blk-mq: re-check for available tags after running the hardware queue
blk-mq: fix hang in bt_get()
blk-mq: move the kdump check to blk_mq_alloc_tag_set
blk-mq: cleanup tag free handling
blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map
blk: introduce generic io stat accounting help function
blk-mq: handle the single queue case in blk_mq_hctx_next_cpu
genhd: check for int overflow in disk_expand_part_tbl()
blk-mq: add blk_mq_free_hctx_request()
blk-mq: export blk_mq_free_request()
blk-mq: use get_cpu/put_cpu instead of preempt_disable/preempt_enable
...
The original behaviour is to refuse to add a new page if the maximum
number of segments has been reached, regardless of the fact the page we
are going to add can be merged into the last segment or not.
Unfortunately, when the system runs under heavy memory fragmentation
conditions, a driver may try to add multiple pages to the last segment.
The original code won't accept them and EBUSY will be reported to
userspace.
This patch modifies the function so it refuses to add a page only in case
the latter starts a new segment and the maximum number of segments has
already been reached.
The bug can be easily reproduced with the st driver:
1) set CONFIG_SCSI_MPT2SAS_MAX_SGE or CONFIG_SCSI_MPT3SAS_MAX_SGE to 16
2) modprobe st buffer_kbs=1024
3) #dd if=/dev/zero of=/dev/st0 bs=1M count=10
dd: error writing `/dev/st0': Device or resource busy
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Cc: Jet Chen <jet.chen@intel.com>
Cc: Tomas Henzl <thenzl@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
This time we have some more new material than we used to have during
the last couple of development cycles.
The most important part of it to me is the introduction of a unified
interface for accessing device properties provided by platform
firmware. It works with Device Trees and ACPI in a uniform way and
drivers using it need not worry about where the properties come
from as long as the platform firmware (either DT or ACPI) makes
them available. It covers both devices and "bare" device node
objects without struct device representation as that turns out to
be necessary in some cases. This has been in the works for quite
a few months (and development cycles) and has been approved by
all of the relevant maintainers.
On top of that, some drivers are switched over to the new interface
(at25, leds-gpio, gpio_keys_polled) and some additional changes are
made to the core GPIO subsystem to allow device drivers to manipulate
GPIOs in the "canonical" way on platforms that provide GPIO information
in their ACPI tables, but don't assign names to GPIO lines (in which
case the driver needs to do that on the basis of what it knows about
the device in question). That also has been approved by the GPIO
core maintainers and the rfkill driver is now going to use it.
Second is support for hardware P-states in the intel_pstate driver.
It uses CPUID to detect whether or not the feature is supported by
the processor in which case it will be enabled by default. However,
it can be disabled entirely from the kernel command line if necessary.
Next is support for a platform firmware interface based on ACPI
operation regions used by the PMIC (Power Management Integrated
Circuit) chips on the Intel Baytrail-T and Baytrail-T-CR platforms.
That interface is used for manipulating power resources and for
thermal management: sensor temperature reporting, trip point setting
and so on.
Also the ACPI core is now going to support the _DEP configuration
information in a limited way. Basically, _DEP it supposed to reflect
off-the-hierarchy dependencies between devices which may be very
indirect, like when AML for one device accesses locations in an
operation region handled by another device's driver (usually, the
device depended on this way is a serial bus or GPIO controller).
The support added this time is sufficient to make the ACPI battery
driver work on Asus T100A, but it is general enough to be able to
cover some other use cases in the future.
Finally, we have a new cpufreq driver for the Loongson1B processor.
In addition to the above, there are fixes and cleanups all over the
place as usual and a traditional ACPICA update to a recent upstream
release.
As far as the fixes go, the ACPI LPSS (Low-power Subsystem) driver
for Intel platforms should be able to handle power management of
the DMA engine correctly, the cpufreq-dt driver should interact
with the thermal subsystem in a better way and the ACPI backlight
driver should handle some more corner cases, among other things.
On top of the ACPICA update there are fixes for race conditions
in the ACPICA's interrupt handling code which might lead to some
random and strange looking failures on some systems.
In the cleanups department the most visible part is the series
of commits targeted at getting rid of the CONFIG_PM_RUNTIME
configuration option. That was triggered by a discussion
regarding the generic power domains code during which we realized
that trying to support certain combinations of PM config options
was painful and not really worth it, because nobody would use them
in production anyway. For this reason, we decided to make
CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and that lead to the
conclusion that the latter became redundant and CONFIG_PM could
be used instead of it. The material here makes that replacement
in a major part of the tree, but there will be at least one more
batch of that in the second part of the merge window.
Specifics:
- Support for retrieving device properties information from ACPI
_DSD device configuration objects and a unified device properties
interface for device drivers (and subsystems) on top of that.
As stated above, this works with Device Trees and ACPI and allows
device drivers to be written in a platform firmware (DT or ACPI)
agnostic way. The at25, leds-gpio and gpio_keys_polled drivers
are now going to use this new interface and the GPIO subsystem
is additionally modified to allow device drivers to assign names
to GPIO resources returned by ACPI _CRS objects (in case _DSD is
not present or does not provide the expected data). The changes
in this set are mostly from Mika Westerberg, Rafael J Wysocki,
Aaron Lu, and Darren Hart with some fixes from others (Fabio Estevam,
Geert Uytterhoeven).
- Support for Hardware Managed Performance States (HWP) as described
in Volume 3, section 14.4, of the Intel SDM in the intel_pstate
driver. CPUID is used to detect whether or not the feature is
supported by the processor. If supported, it will be enabled
automatically unless the intel_pstate=no_hwp switch is present in
the kernel command line. From Dirk Brandewie.
- New Intel Broadwell-H ID for intel_pstate (Dirk Brandewie).
- Support for firmware interface based on ACPI operation regions
used by the PMIC chips on the Intel Baytrail-T and Baytrail-T-CR
platforms for power resource control and thermal management
(Aaron Lu).
- Limited support for retrieving off-the-hierarchy dependencies
between devices from ACPI _DEP device configuration objects
and deferred probing support for the ACPI battery driver based
on the _DEP information to make that driver work on Asus T100A
(Lan Tianyu).
- New cpufreq driver for the Loongson1B processor (Kelvin Cheung).
- ACPICA update to upstream revision 20141107 which only affects
tools (Bob Moore).
- Fixes for race conditions in the ACPICA's interrupt handling
code and in the ACPI code related to system suspend and resume
(Lv Zheng and Rafael J Wysocki).
- ACPI core fix for an RCU-related issue in the ioremap() regions
management code that slowed down significantly after CPUs had
been allowed to enter idle states even if they'd had RCU callbakcs
queued and triggered some problems in certain proprietary graphics
driver (and elsewhere). The fix replaces synchronize_rcu() in
that code with synchronize_rcu_expedited() which makes the issue
go away. From Konstantin Khlebnikov.
- ACPI LPSS (Low-Power Subsystem) driver fix to handle power
management of the DMA engine included into the LPSS correctly.
The problem is that the DMA engine doesn't have ACPI PM support
of its own and it simply is turned off when the last LPSS device
having ACPI PM support goes into D3cold. To work around that,
the PM domain used by the ACPI LPSS driver is redesigned so at
least one device with ACPI PM support will be on as long as the
DMA engine is in use. From Andy Shevchenko.
- ACPI backlight driver fix to avoid using it on "Win8-compatible"
systems where it doesn't work and where it was used by default by
mistake (Aaron Lu).
- Assorted minor ACPI core fixes and cleanups from Tomasz Nowicki,
Sudeep Holla, Huang Rui, Hanjun Guo, Fabian Frederick, and
Ashwin Chaugule (mostly related to the upcoming ARM64 support).
- Intel RAPL (Running Average Power Limit) power capping driver
fixes and improvements including new processor IDs (Jacob Pan).
- Generic power domains modification to power up domains after
attaching devices to them to meet the expectations of device
drivers and bus types assuming devices to be accessible at
probe time (Ulf Hansson).
- Preliminary support for controlling device clocks from the
generic power domains core code and modifications of the
ARM/shmobile platform to use that feature (Ulf Hansson).
- Assorted minor fixes and cleanups of the generic power
domains core code (Ulf Hansson, Geert Uytterhoeven).
- Assorted minor fixes and cleanups of the device clocks control
code in the PM core (Geert Uytterhoeven, Grygorii Strashko).
- Consolidation of device power management Kconfig options by making
CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and removing the latter
which is now redundant (Rafael J Wysocki and Kevin Hilman). That
is the first batch of the changes needed for this purpose.
- Core device runtime power management support code cleanup related
to the execution of callbacks (Andrzej Hajda).
- cpuidle ARM support improvements (Lorenzo Pieralisi).
- cpuidle cleanup related to the CPUIDLE_FLAG_TIME_VALID flag and
a new MAINTAINERS entry for ARM Exynos cpuidle (Daniel Lezcano and
Bartlomiej Zolnierkiewicz).
- New cpufreq driver callback (->ready) to be executed when the
cpufreq core is ready to use a given policy object and cpufreq-dt
driver modification to use that callback for cooling device
registration (Viresh Kumar).
- cpufreq core fixes and cleanups (Viresh Kumar, Vince Hsu,
James Geboski, Tomeu Vizoso).
- Assorted fixes and cleanups in the cpufreq-pcc, intel_pstate,
cpufreq-dt, pxa2xx cpufreq drivers (Lenny Szubowicz, Ethan Zhao,
Stefan Wahren, Petr Cvek).
- OPP (Operating Performance Points) framework modification to
allow OPPs to be removed too and update of a few cpufreq drivers
(cpufreq-dt, exynos5440, imx6q, cpufreq) to remove OPPs (added
during initialization) on driver removal (Viresh Kumar).
- Hibernation core fixes and cleanups (Tina Ruchandani and
Markus Elfring).
- PM Kconfig fix related to CPU power management (Pankaj Dubey).
- cpupower tool fix (Prarit Bhargava).
/
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Merge tag 'pm+acpi-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management updates from Rafael Wysocki:
"This time we have some more new material than we used to have during
the last couple of development cycles.
The most important part of it to me is the introduction of a unified
interface for accessing device properties provided by platform
firmware. It works with Device Trees and ACPI in a uniform way and
drivers using it need not worry about where the properties come from
as long as the platform firmware (either DT or ACPI) makes them
available. It covers both devices and "bare" device node objects
without struct device representation as that turns out to be necessary
in some cases. This has been in the works for quite a few months (and
development cycles) and has been approved by all of the relevant
maintainers.
On top of that, some drivers are switched over to the new interface
(at25, leds-gpio, gpio_keys_polled) and some additional changes are
made to the core GPIO subsystem to allow device drivers to manipulate
GPIOs in the "canonical" way on platforms that provide GPIO
information in their ACPI tables, but don't assign names to GPIO lines
(in which case the driver needs to do that on the basis of what it
knows about the device in question). That also has been approved by
the GPIO core maintainers and the rfkill driver is now going to use
it.
Second is support for hardware P-states in the intel_pstate driver.
It uses CPUID to detect whether or not the feature is supported by the
processor in which case it will be enabled by default. However, it
can be disabled entirely from the kernel command line if necessary.
Next is support for a platform firmware interface based on ACPI
operation regions used by the PMIC (Power Management Integrated
Circuit) chips on the Intel Baytrail-T and Baytrail-T-CR platforms.
That interface is used for manipulating power resources and for
thermal management: sensor temperature reporting, trip point setting
and so on.
Also the ACPI core is now going to support the _DEP configuration
information in a limited way. Basically, _DEP it supposed to reflect
off-the-hierarchy dependencies between devices which may be very
indirect, like when AML for one device accesses locations in an
operation region handled by another device's driver (usually, the
device depended on this way is a serial bus or GPIO controller). The
support added this time is sufficient to make the ACPI battery driver
work on Asus T100A, but it is general enough to be able to cover some
other use cases in the future.
Finally, we have a new cpufreq driver for the Loongson1B processor.
In addition to the above, there are fixes and cleanups all over the
place as usual and a traditional ACPICA update to a recent upstream
release.
As far as the fixes go, the ACPI LPSS (Low-power Subsystem) driver for
Intel platforms should be able to handle power management of the DMA
engine correctly, the cpufreq-dt driver should interact with the
thermal subsystem in a better way and the ACPI backlight driver should
handle some more corner cases, among other things.
On top of the ACPICA update there are fixes for race conditions in the
ACPICA's interrupt handling code which might lead to some random and
strange looking failures on some systems.
In the cleanups department the most visible part is the series of
commits targeted at getting rid of the CONFIG_PM_RUNTIME configuration
option. That was triggered by a discussion regarding the generic
power domains code during which we realized that trying to support
certain combinations of PM config options was painful and not really
worth it, because nobody would use them in production anyway. For
this reason, we decided to make CONFIG_PM_SLEEP select
CONFIG_PM_RUNTIME and that lead to the conclusion that the latter
became redundant and CONFIG_PM could be used instead of it. The
material here makes that replacement in a major part of the tree, but
there will be at least one more batch of that in the second part of
the merge window.
Specifics:
- Support for retrieving device properties information from ACPI _DSD
device configuration objects and a unified device properties
interface for device drivers (and subsystems) on top of that. As
stated above, this works with Device Trees and ACPI and allows
device drivers to be written in a platform firmware (DT or ACPI)
agnostic way. The at25, leds-gpio and gpio_keys_polled drivers are
now going to use this new interface and the GPIO subsystem is
additionally modified to allow device drivers to assign names to
GPIO resources returned by ACPI _CRS objects (in case _DSD is not
present or does not provide the expected data). The changes in
this set are mostly from Mika Westerberg, Rafael J Wysocki, Aaron
Lu, and Darren Hart with some fixes from others (Fabio Estevam,
Geert Uytterhoeven).
- Support for Hardware Managed Performance States (HWP) as described
in Volume 3, section 14.4, of the Intel SDM in the intel_pstate
driver. CPUID is used to detect whether or not the feature is
supported by the processor. If supported, it will be enabled
automatically unless the intel_pstate=no_hwp switch is present in
the kernel command line. From Dirk Brandewie.
- New Intel Broadwell-H ID for intel_pstate (Dirk Brandewie).
- Support for firmware interface based on ACPI operation regions used
by the PMIC chips on the Intel Baytrail-T and Baytrail-T-CR
platforms for power resource control and thermal management (Aaron
Lu).
- Limited support for retrieving off-the-hierarchy dependencies
between devices from ACPI _DEP device configuration objects and
deferred probing support for the ACPI battery driver based on the
_DEP information to make that driver work on Asus T100A (Lan
Tianyu).
- New cpufreq driver for the Loongson1B processor (Kelvin Cheung).
- ACPICA update to upstream revision 20141107 which only affects
tools (Bob Moore).
- Fixes for race conditions in the ACPICA's interrupt handling code
and in the ACPI code related to system suspend and resume (Lv Zheng
and Rafael J Wysocki).
- ACPI core fix for an RCU-related issue in the ioremap() regions
management code that slowed down significantly after CPUs had been
allowed to enter idle states even if they'd had RCU callbakcs
queued and triggered some problems in certain proprietary graphics
driver (and elsewhere). The fix replaces synchronize_rcu() in that
code with synchronize_rcu_expedited() which makes the issue go
away. From Konstantin Khlebnikov.
- ACPI LPSS (Low-Power Subsystem) driver fix to handle power
management of the DMA engine included into the LPSS correctly. The
problem is that the DMA engine doesn't have ACPI PM support of its
own and it simply is turned off when the last LPSS device having
ACPI PM support goes into D3cold. To work around that, the PM
domain used by the ACPI LPSS driver is redesigned so at least one
device with ACPI PM support will be on as long as the DMA engine is
in use. From Andy Shevchenko.
- ACPI backlight driver fix to avoid using it on "Win8-compatible"
systems where it doesn't work and where it was used by default by
mistake (Aaron Lu).
- Assorted minor ACPI core fixes and cleanups from Tomasz Nowicki,
Sudeep Holla, Huang Rui, Hanjun Guo, Fabian Frederick, and Ashwin
Chaugule (mostly related to the upcoming ARM64 support).
- Intel RAPL (Running Average Power Limit) power capping driver fixes
and improvements including new processor IDs (Jacob Pan).
- Generic power domains modification to power up domains after
attaching devices to them to meet the expectations of device
drivers and bus types assuming devices to be accessible at probe
time (Ulf Hansson).
- Preliminary support for controlling device clocks from the generic
power domains core code and modifications of the ARM/shmobile
platform to use that feature (Ulf Hansson).
- Assorted minor fixes and cleanups of the generic power domains core
code (Ulf Hansson, Geert Uytterhoeven).
- Assorted minor fixes and cleanups of the device clocks control code
in the PM core (Geert Uytterhoeven, Grygorii Strashko).
- Consolidation of device power management Kconfig options by making
CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and removing the latter
which is now redundant (Rafael J Wysocki and Kevin Hilman). That
is the first batch of the changes needed for this purpose.
- Core device runtime power management support code cleanup related
to the execution of callbacks (Andrzej Hajda).
- cpuidle ARM support improvements (Lorenzo Pieralisi).
- cpuidle cleanup related to the CPUIDLE_FLAG_TIME_VALID flag and a
new MAINTAINERS entry for ARM Exynos cpuidle (Daniel Lezcano and
Bartlomiej Zolnierkiewicz).
- New cpufreq driver callback (->ready) to be executed when the
cpufreq core is ready to use a given policy object and cpufreq-dt
driver modification to use that callback for cooling device
registration (Viresh Kumar).
- cpufreq core fixes and cleanups (Viresh Kumar, Vince Hsu, James
Geboski, Tomeu Vizoso).
- Assorted fixes and cleanups in the cpufreq-pcc, intel_pstate,
cpufreq-dt, pxa2xx cpufreq drivers (Lenny Szubowicz, Ethan Zhao,
Stefan Wahren, Petr Cvek).
- OPP (Operating Performance Points) framework modification to allow
OPPs to be removed too and update of a few cpufreq drivers
(cpufreq-dt, exynos5440, imx6q, cpufreq) to remove OPPs (added
during initialization) on driver removal (Viresh Kumar).
- Hibernation core fixes and cleanups (Tina Ruchandani and Markus
Elfring).
- PM Kconfig fix related to CPU power management (Pankaj Dubey).
- cpupower tool fix (Prarit Bhargava)"
* tag 'pm+acpi-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (120 commits)
i2c-omap / PM: Drop CONFIG_PM_RUNTIME from i2c-omap.c
dmaengine / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
tools: cpupower: fix return checks for sysfs_get_idlestate_count()
drivers: sh / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
e1000e / igb / PM: Eliminate CONFIG_PM_RUNTIME
MMC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
MFD / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
misc / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
media / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
input / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
leds: leds-gpio: Fix multiple instances registration without 'label' property
iio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
hsi / OMAP / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
i2c-hid / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
drm / exynos / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
gpio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
hwrandom / exynos / PM: Use CONFIG_PM in #ifdef
block / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
USB / PM: Drop CONFIG_PM_RUNTIME from the USB core
PM: Merge the SET*_RUNTIME_PM_OPS() macros
...
When a CPU is hotplugged, the current blk-mq spews a warning like:
kobject '(null)' (ffffe8ffffc8b5d8): tried to add an uninitialized object, something is seriously wrong.
CPU: 1 PID: 1386 Comm: systemd-udevd Not tainted 3.18.0-rc7-2.g088d59b-default #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_171129-lamiak 04/01/2014
0000000000000000 0000000000000002 ffffffff81605f07 ffffe8ffffc8b5d8
ffffffff8132c7a0 ffff88023341d370 0000000000000020 ffff8800bb05bd58
ffff8800bb05bd08 000000000000a0a0 000000003f441940 0000000000000007
Call Trace:
[<ffffffff81005306>] dump_trace+0x86/0x330
[<ffffffff81005644>] show_stack_log_lvl+0x94/0x170
[<ffffffff81006d21>] show_stack+0x21/0x50
[<ffffffff81605f07>] dump_stack+0x41/0x51
[<ffffffff8132c7a0>] kobject_add+0xa0/0xb0
[<ffffffff8130aee1>] blk_mq_register_hctx+0x91/0xb0
[<ffffffff8130b82e>] blk_mq_sysfs_register+0x3e/0x60
[<ffffffff81309298>] blk_mq_queue_reinit_notify+0xf8/0x190
[<ffffffff8107cfdc>] notifier_call_chain+0x4c/0x70
[<ffffffff8105fd23>] cpu_notify+0x23/0x50
[<ffffffff81060037>] _cpu_up+0x157/0x170
[<ffffffff810600d9>] cpu_up+0x89/0xb0
[<ffffffff815fa5b5>] cpu_subsys_online+0x35/0x80
[<ffffffff814323cd>] device_online+0x5d/0xa0
[<ffffffff81432485>] online_store+0x75/0x80
[<ffffffff81236a5a>] kernfs_fop_write+0xda/0x150
[<ffffffff811c5532>] vfs_write+0xb2/0x1f0
[<ffffffff811c5f42>] SyS_write+0x42/0xb0
[<ffffffff8160c4ed>] system_call_fastpath+0x16/0x1b
[<00007f0132fb24e0>] 0x7f0132fb24e0
This is indeed because of an uninitialized kobject for blk_mq_ctx.
The blk_mq_ctx kobjects are initialized in blk_mq_sysfs_init(), but it
goes loop over hctx_for_each_ctx(), i.e. it initializes only for
online CPUs. Thus, when a CPU is hotplugged, the ctx for the newly
onlined CPU is registered without initialization.
This patch fixes the issue by initializing the all ctx kobjects
belonging to each queue.
Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=908794
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
