Now queue_io() is called from dec_pending(), which may be called with
interrupts disabled, so queue_io() must not enable interrupts
unconditionally and must save/restore the current interrupts status.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA doesn't mandate any ordering
against other bio's. This patch relaxes ordering around flushes.
* A flush bio is no longer deferred to workqueue directly. It's
processed like other bio's but __split_and_process_bio() uses
md->flush_bio as the clone source. md->flush_bio is initialized to
empty flush during md initialization and shared for all flushes.
* As a flush bio now travels through the same execution path as other
bio's, there's no need for dedicated error handling path either. It
can use the same error handling path in dec_pending(). Dedicated
error handling removed along with md->flush_error.
* When dec_pending() detects that a flush has completed, it checks
whether the original bio has data. If so, the bio is queued to the
deferred list w/ REQ_FLUSH cleared; otherwise, it's completed.
* As flush sequencing is handled in the usual issue/completion path,
dm_wq_work() no longer needs to handle flushes differently. Now its
only responsibility is re-issuing deferred bio's the same way as
_dm_request() would. REQ_FLUSH handling logic including
process_flush() is dropped.
* There's no reason for queue_io() and dm_wq_work() write lock
dm->io_lock. queue_io() now only uses md->deferred_lock and
dm_wq_work() read locks dm->io_lock.
* bio's no longer need to be queued on the deferred list while a flush
is in progress making DMF_QUEUE_IO_TO_THREAD unncessary. Drop it.
This avoids stalling the device during flushes and simplifies the
implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This patch converts request-based dm to support the new REQ_FLUSH/FUA.
The original request-based flush implementation depended on
request_queue blocking other requests while a barrier sequence is in
progress, which is no longer true for the new REQ_FLUSH/FUA.
In general, request-based dm doesn't have infrastructure for cloning
one source request to multiple targets, but the original flush
implementation had a special mostly independent path which can issue
flushes to multiple targets and sequence them. However, the
capability isn't currently in use and adds a lot of complexity.
Moreoever, it's unlikely to be useful in its current form as it
doesn't make sense to be able to send out flushes to multiple targets
when write requests can't be.
This patch rips out special flush code path and deals handles
REQ_FLUSH/FUA requests the same way as other requests. The only
special treatment is that REQ_FLUSH requests use the block address 0
when finding target, which is enough for now.
* added BUG_ON(!dm_target_is_valid(ti)) in dm_request_fn() as
suggested by Mike Snitzer
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Tested-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This patch converts bio-based dm to support REQ_FLUSH/FUA instead of
now deprecated REQ_HARDBARRIER.
* -EOPNOTSUPP handling logic dropped.
* Preflush is handled as before but postflush is dropped and replaced
with passing down REQ_FUA to member request_queues. This replaces
one array wide cache flush w/ member specific FUA writes.
* __split_and_process_bio() now calls __clone_and_map_flush() directly
for flushes and guarantees all FLUSH bio's going to targets are zero
` length.
* It's now guaranteed that all FLUSH bio's which are passed onto dm
targets are zero length. bio_empty_barrier() tests are replaced
with REQ_FLUSH tests.
* Empty WRITE_BARRIERs are replaced with WRITE_FLUSHes.
* Dropped unlikely() around REQ_FLUSH tests. Flushes are not unlikely
enough to be marked with unlikely().
* Block layer now filters out REQ_FLUSH/FUA bio's if the request_queue
doesn't support cache flushing. Advertise REQ_FLUSH | REQ_FUA
capability.
* Request based dm isn't converted yet. dm_init_request_based_queue()
resets flush support to 0 for now. To avoid disturbing request
based dm code, dm->flush_error is added for bio based dm while
requested based dm continues to use dm->barrier_error.
Lightly tested linear, stripe, raid1, snap and crypt targets. Please
proceed with caution as I'm not familiar with the code base.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: dm-devel@redhat.com
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Currently __blk_rq_prep_clone() copies only REQ_WRITE and REQ_DISCARD.
There's no reason to omit other command flags and REQ_FUA needs to be
copied to implement FUA support in request-based dm.
REQ_COMMON_MASK which specifies flags to be copied from bio to request
already identifies all the command flags. Define REQ_CLONE_MASK to be
the same as REQ_COMMON_MASK for clarity and make __blk_rq_prep_clone()
copy all flags in the mask.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This patch converts md to support REQ_FLUSH/FUA instead of now
deprecated REQ_HARDBARRIER. In the core part (md.c), the following
changes are notable.
* Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA don't interfere with
processing of other requests and thus there is no reason to mark the
queue congested while FLUSH/FUA is in progress.
* REQ_FLUSH/FUA failures are final and its users don't need retry
logic. Retry logic is removed.
* Preflush needs to be issued to all member devices but FUA writes can
be handled the same way as other writes - their processing can be
deferred to request_queue of member devices. md_barrier_request()
is renamed to md_flush_request() and simplified accordingly.
For linear, raid0 and multipath, the core changes are enough. raid1,
5 and 10 need the following conversions.
* raid1: Handling of FLUSH/FUA bio's can simply be deferred to
request_queues of member devices. Barrier related logic removed.
* raid5: Queue draining logic dropped. FUA bit is propagated through
biodrain and stripe resconstruction such that all the updated parts
of the stripe are written out with FUA writes if any of the dirtying
writes was FUA. preread_active_stripes handling in make_request()
is updated as suggested by Neil Brown.
* raid10: FUA bit needs to be propagated to write clones.
linear, raid0, 1, 5 and 10 tested.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
VIRTIO_F_BARRIER is deprecated. Replace it with VIRTIO_F_FLUSH
support.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Remove now unused REQ_HARDBARRIER support. virtio_blk already
supports REQ_FLUSH and the usefulness of REQ_FUA for virtio_blk is
questionable at this point, so there's nothing else to do to support
new REQ_FLUSH/FUA interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Deprecate REQ_HARDBARRIER and implement REQ_FLUSH/FUA instead. Also,
instead of checking file->f_op->fsync() directly, look at the value of
vfs_fsync() and ignore -EINVAL return.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Update blkdev_issue_flush() to use new REQ_FLUSH interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
rq->rq_disk and bio->bi_bdev->bd_disk may differ if a request has
passed through remapping drivers. FSEQ_DATA request incorrectly
followed bio->bi_bdev->bd_disk ending up being issued w/ mismatching
rq_disk. Make it follow orig_rq->rq_disk.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Tested-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
While completing a request from a REQ_FLUSH/FUA sequence, another
request can be pushed to the request queue. If a driver tests
elv_queue_empty() before completing a request and runs the queue again
only if the queue wasn't empty, this may lead to hang. Please note
that most drivers either kick the queue unconditionally or test queue
emptiness after completing the current request and don't have this
problem.
This patch removes this possibility by making REQ_FLUSH/FUA sequence
code kick the queue if the queue was empty before completing a request
from REQ_FLUSH/FUA sequence.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
init_flush_request() only set REQ_FLUSH when initializing flush
requests making them READ requests. Use WRITE_FLUSH instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
We need to call blk_rq_init and elv_insert for all cases in queue_next_fseq,
so take these calls into common code. Also move the end_io initialization
from queue_flush into queue_next_fseq and rename queue_flush to
init_flush_request now that it's old name doesn't apply anymore.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
There are a number of make_request based drivers which don't support
cache flushes. Filter out flush bio's in __generic_make_request() so
that they don't have to worry about them. All FLUSH/FUA requests with
data are converted to regular IO requests and empty ones are completed
immediately.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Now that the backend conversion is complete, export sequenced
FLUSH/FUA capability through REQ_FLUSH/FUA flags. REQ_FLUSH means the
device cache should be flushed before executing the request. REQ_FUA
means that the data in the request should be on non-volatile media on
completion.
Block layer will choose the correct way of implementing the semantics
and execute it. The request may be passed to the device directly if
the device can handle it; otherwise, it will be sequenced using one or
more proxy requests. Devices will never see REQ_FLUSH and/or FUA
which it doesn't support.
Also, unlike the original REQ_HARDBARRIER, REQ_FLUSH/FUA requests are
never failed with -EOPNOTSUPP. If the underlying device doesn't
support FLUSH/FUA, the block layer simply make those noop. IOW, it no
longer distinguishes between writeback cache which doesn't support
cache flush and writethrough/no cache. Devices which have WB cache
w/o flush are very difficult to come by these days and there's nothing
much we can do anyway, so it doesn't make sense to require everyone to
implement -EOPNOTSUPP handling. This will simplify filesystems and
block drivers as they can drop -EOPNOTSUPP retry logic for barriers.
* QUEUE_ORDERED_* are removed and QUEUE_FSEQ_* are moved into
blk-flush.c.
* REQ_FLUSH w/o data can also be directly passed to drivers without
sequencing but some drivers assume that zero length requests don't
have rq->bio which isn't true for these requests requiring the use
of proxy requests.
* REQ_COMMON_MASK now includes REQ_FLUSH | REQ_FUA so that they are
copied from bio to request.
* WRITE_BARRIER is marked deprecated and WRITE_FLUSH, WRITE_FUA and
WRITE_FLUSH_FUA are added.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
With ordering requirements dropped, barrier and ordered are misnomers.
Now all block layer does is sequencing FLUSH and FUA. Rename them to
flush.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Without ordering requirements, barrier and ordering are minomers.
Rename block/blk-barrier.c to block/blk-flush.c. Rename of symbols
will follow.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Filesystems will take all the responsibilities for ordering requests
around commit writes and will only indicate how the commit writes
themselves should be handled by block layers. This patch drops
barrier ordering by queue draining from block layer. Ordering by
draining implementation was somewhat invasive to request handling.
List of notable changes follow.
* Each queue has 1 bit color which is flipped on each barrier issue.
This is used to track whether a given request is issued before the
current barrier or not. REQ_ORDERED_COLOR flag and coloring
implementation in __elv_add_request() are removed.
* Requests which shouldn't be processed yet for draining were stalled
by returning -EAGAIN from blk_do_ordered() according to the test
result between blk_ordered_req_seq() and blk_blk_ordered_cur_seq().
This logic is removed.
* Draining completion logic in elv_completed_request() removed.
* All barrier sequence requests were queued to request queue and then
trckled to lower layer according to progress and thus maintaining
request orders during requeue was necessary. This is replaced by
queueing the next request in the barrier sequence only after the
current one is complete from blk_ordered_complete_seq(), which
removes the need for multiple proxy requests in struct request_queue
and the request sorting logic in the ELEVATOR_INSERT_REQUEUE path of
elv_insert().
* As barriers no longer have ordering constraints, there's no need to
dump the whole elevator onto the dispatch queue on each barrier.
Insert barriers at the front instead.
* If other barrier requests come to the front of the dispatch queue
while one is already in progress, they are stored in
q->pending_barriers and restored to dispatch queue one-by-one after
each barrier completion from blk_ordered_complete_seq().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Make the following cleanups in preparation of barrier/flush update.
* blk_do_ordered() declaration is moved from include/linux/blkdev.h to
block/blk.h.
* blk_do_ordered() now returns pointer to struct request, with %NULL
meaning "try the next request" and ERR_PTR(-EAGAIN) "try again
later". The third case will be dropped with further changes.
* In the initialization of proxy barrier request, data direction is
already set by init_request_from_bio(). Drop unnecessary explicit
REQ_WRITE setting and move init_request_from_bio() above REQ_FUA
flag setting.
* add_request() is collapsed into __make_request().
These changes don't make any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
REQ_HARDBARRIER is deprecated. Remove spurious uses in the following
users. Please note that other than osdblk, all other uses were
already spurious before deprecation.
* osdblk: osdblk_rq_fn() won't receive any request with
REQ_HARDBARRIER set. Remove the test for it.
* pktcdvd: use of REQ_HARDBARRIER in pkt_generic_packet() doesn't mean
anything. Removed.
* aic7xxx_old: Setting MSG_ORDERED_Q_TAG on REQ_HARDBARRIER is
spurious. Removed.
* sas_scsi_host: Setting TASK_ATTR_ORDERED on REQ_HARDBARRIER is
spurious. Removed.
* scsi_tcq: The ordered tag path wasn't being used anyway. Removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: James Bottomley <James.Bottomley@suse.de>
Cc: Peter Osterlund <petero2@telia.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Barrier is deemed too heavy and will soon be replaced by FLUSH/FUA
requests. Deprecate barrier. All REQ_HARDBARRIERs are failed with
-EOPNOTSUPP and blk_queue_ordered() is replaced with simpler
blk_queue_flush().
blk_queue_flush() takes combinations of REQ_FLUSH and FUA. If a
device has write cache and can flush it, it should set REQ_FLUSH. If
the device can handle FUA writes, it should also set REQ_FUA.
All blk_queue_ordered() users are converted.
* ORDERED_DRAIN is mapped to 0 which is the default value.
* ORDERED_DRAIN_FLUSH is mapped to REQ_FLUSH.
* ORDERED_DRAIN_FLUSH_FUA is mapped to REQ_FLUSH | REQ_FUA.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Nobody is making meaningful use of ORDERED_BY_TAG now and queue
draining for barrier requests will be removed soon which will render
the advantage of tag ordering moot. Kill ORDERED_BY_TAG. The
following users are affected.
* brd: converted to ORDERED_DRAIN.
* virtio_blk: ORDERED_TAG path was already marked deprecated. Removed.
* xen-blkfront: ORDERED_TAG case dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
loop implements FLUSH using fsync but was incorrectly setting its
ordered mode to DRAIN. Change it to DRAIN_FLUSH. In practice, this
doesn't change anything as loop doesn't make use of the block layer
ordered implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Unplugging from a request function doesn't really help much (it's
already in the request_fn) and soon block layer will be updated to mix
barrier sequence with other commands, so there's no need to treat
queue flushing any differently.
ide was the only user of blk_queue_flushing(). Remove it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: PIT: free irq source id in handling error path
KVM: destroy workqueue on kvm_create_pit() failures
KVM: fix poison overwritten caused by using wrong xstate size
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel: (58 commits)
drm/i915,intel_agp: Add support for Sandybridge D0
drm/i915: fix render pipe control notify on sandybridge
agp/intel: set 40-bit dma mask on Sandybridge
drm/i915: Remove the conflicting BUG_ON()
drm/i915/suspend: s/IS_IRONLAKE/HAS_PCH_SPLIT/
drm/i915/suspend: Flush register writes before busy-waiting.
i915: disable DAC on Ironlake also when doing CRT load detection.
drm/i915: wait for actual vblank, not just 20ms
drm/i915: make sure eDP PLL is enabled at the right time
drm/i915: fix VGA plane disable for Ironlake+
drm/i915: eDP mode set sequence corrections
drm/i915: add panel reset workaround
drm/i915: Enable RC6 on Ironlake.
drm/i915/sdvo: Only set is_lvds if we have a valid fixed mode.
drm/i915: Set up a render context on Ironlake
drm/i915 invalidate indirect state pointers at end of ring exec
drm/i915: Wake-up wait_request() from elapsed hang-check (v2)
drm/i915: Apply i830 errata for cursor alignment
drm/i915: Only update i845/i865 CURBASE when disabled (v2)
drm/i915: FBC is updated within set_base() so remove second call in mode_set()
...
This one is missed in last pipe control fix for sandybridge,
that really unmask interrupt bit for notify in render engine IMR.
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
We now attempt to free "active" objects following a GPU hang as either
the GPU will be reset or the hang is permenant. In either case, the GPU
writes will not be flushed to main memory and it should be safe to
return that memory back to the system.
The BUG_ON(active) is thus overkill and can erroneously fire after a
EIO.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
For the shared paths on the next generation chipsets.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
Like on Sandybridge, disabling the DAC here when doing CRT load detect
avoids forever hangs waiting on the hardware.
test procedure on HP 2740p:
boot with no VGA plugged in, start X,
plug in VGA monitor (1280x1024)
chvt 3
machine hangs waiting forever.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Waiting for a hard coded 20ms isn't always enough to make sure a vblank
period has actually occurred, so add code to make sure we really have
passed through a vblank period (or that the pipe is off when disabling).
This prevents problems with mode setting and link training, and seems to
fix a bug like https://bugs.freedesktop.org/show_bug.cgi?id=29278, but
on an HP 8440p instead. Hopefully also fixes
https://bugs.freedesktop.org/show_bug.cgi?id=29141.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
With the introduction of the new unified work queue thread pools,
we lost one feature: It's no longer possible to know which worker
is causing the CPU to wake out of idle. The result is that PowerTOP
now reports a lot of "kworker/a:b" instead of more readable results.
This patch adds a pair of tracepoints to the new workqueue code,
similar in style to the timer/hrtimer tracepoints.
With this pair of tracepoints, the next PowerTOP can correctly
report which work item caused the wakeup (and how long it took):
Interrupt (43) i915 time 3.51ms wakeups 141
Work ieee80211_iface_work time 0.81ms wakeups 29
Work do_dbs_timer time 0.55ms wakeups 24
Process Xorg time 21.36ms wakeups 4
Timer sched_rt_period_timer time 0.01ms wakeups 1
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The "Configure" word tends to make user believe they have to say 'yes'
to be able to choose the number of procs/nodes. "Enable" should be
unambiguous enough.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Like the mlock() change previously, this makes the stack guard check
code use vma->vm_prev to see what the mapping below the current stack
is, rather than have to look it up with find_vma().
Also, accept an abutting stack segment, since that happens naturally if
you split the stack with mlock or mprotect.
Tested-by: Ian Campbell <ijc@hellion.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we've split the stack vma, only the lowest one has the guard page.
Now that we have a doubly linked list of vma's, checking this is trivial.
Tested-by: Ian Campbell <ijc@hellion.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's a really simple list, and several of the users want to go backwards
in it to find the previous vma. So rather than have to look up the
previous entry with 'find_vma_prev()' or something similar, just make it
doubly linked instead.
Tested-by: Ian Campbell <ijc@hellion.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Apparently, the check for a 6-byte ID string introduced by commit
426c457a32 ("mtd: nand: extend NAND flash
detection to new MLC chips") is NOT sufficient to determine whether or
not a Samsung chip uses their new MLC detection scheme or the old,
standard scheme. This adds a condition to check cell type.
Signed-off-by: Tilman Sauerbeck <tilman@code-monkey.de>
Signed-off-by: Brian Norris <norris@broadcom.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org
This list moved to lists.ozlabs.org quite some time ago.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All these lists moved to lists.ozlabs.org quite a while ago.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Chapter 6 is right about mutex_trylock, but chapter 10 wasn't. This error
was introduced during semaphore-to-mutex conversion of the Unreliable
guide. :-)
If user context which performs mutex_lock() or mutex_trylock() is
preempted by interrupt context which performs mutex_trylock() on the same
mutex instance, a deadlock occurs. This is because these functions do not
disable local IRQs when they operate on mutex->wait_lock.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
