Commit 08778795 ("block: Fix nr_vecs for inline integrity vectors") from
Martin introduces the function bip_integrity_vecs(get the useful vectors)
to fix the issue about nr_vecs for inline integrity vectors that reported
by David Milburn.
But it seems that bip_integrity_vecs() will return the wrong number if the
bio is not based on any bio_set for some reason(bio->bi_pool == NULL),
because in that case, the bip_inline_vecs[0] is malloced directly. So
here we add the bip_max_vcnt to record the count of vector slots, and
cleanup the function bip_integrity_vecs().
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently, blk-mq uses a percpu_counter to keep track of how many
usages are in flight. The percpu_counter is drained while freezing to
ensure that no usage is left in-flight after freezing is complete.
blk_mq_queue_enter/exit() and blk_mq_[un]freeze_queue() implement this
per-cpu gating mechanism.
This type of code has relatively high chance of subtle bugs which are
extremely difficult to trigger and it's way too hairy to be open coded
in blk-mq. percpu_ref can serve the same purpose after the recent
changes. This patch replaces the open-coded per-cpu usage counting
and draining mechanism with percpu_ref.
blk_mq_queue_enter() performs tryget_live on the ref and exit()
performs put. blk_mq_freeze_queue() kills the ref and waits until the
reference count reaches zero. blk_mq_unfreeze_queue() revives the ref
and wakes up the waiters.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Keeping __blk_mq_drain_queue() as a separate function doesn't buy us
anything and it's gonna be further simplified. Let's flatten it into
its caller.
This patch doesn't make any functional change.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
blk_mq freezing is entangled with generic bypassing which bypasses
blkcg and io scheduler and lets IO requests fall through the block
layer to the drivers in FIFO order. This allows forward progress on
IOs with the advanced features disabled so that those features can be
configured or altered without worrying about stalling IO which may
lead to deadlock through memory allocation.
However, generic bypassing doesn't quite fit blk-mq. blk-mq currently
doesn't make use of blkcg or ioscheds and it maps bypssing to
freezing, which blocks request processing and drains all the in-flight
ones. This causes problems as bypassing assumes that request
processing is online. blk-mq works around this by conditionally
allowing request processing for the problem case - during queue
initialization.
Another weirdity is that except for during queue cleanup, bypassing
started on the generic side prevents blk-mq from processing new
requests but doesn't drain the in-flight ones. This shouldn't break
anything but again highlights that something isn't quite right here.
The root cause is conflating blk-mq freezing and generic bypassing
which are two different mechanisms. The only intersecting purpose
that they serve is during queue cleanup. Let's properly separate
blk-mq freezing from generic bypassing and simply use it where
necessary.
* request_queue->mq_freeze_depth is added and
blk_mq_[un]freeze_queue() now operate on this counter instead of
->bypass_depth. The replacement for QUEUE_FLAG_BYPASS isn't added
but the counter is tested directly. This will be further updated by
later changes.
* blk_mq_drain_queue() is dropped and "__" prefix is dropped from
blk_mq_freeze_queue(). Queue cleanup path now calls
blk_mq_freeze_queue() directly.
* blk_queue_enter()'s fast path condition is simplified to simply
check @q->mq_freeze_depth. Previously, the condition was
!blk_queue_dying(q) &&
(!blk_queue_bypass(q) || !blk_queue_init_done(q))
mq_freeze_depth is incremented right after dying is set and
blk_queue_init_done() exception isn't necessary as blk-mq doesn't
start frozen, which only leaves the blk_queue_bypass() test which
can be replaced by @q->mq_freeze_depth test.
This change simplifies the code and reduces confusion in the area.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently, both blk_queue_bypass_start() and blk_mq_freeze_queue()
skip queue draining if bypass_depth was already above zero. The
assumption is that the one which bumped the bypass_depth should have
performed draining already; however, there's nothing which prevents a
new instance of bypassing/freezing from starting before the previous
one finishes draining. The current code may allow the later
bypassing/freezing instances to complete while there still are
in-flight requests which haven't finished draining.
Fix it by draining regardless of bypass_depth. We still skip draining
from blk_queue_bypass_start() while the queue is initializing to avoid
introducing excessive delays during boot. INIT_DONE setting is moved
above the initial blk_queue_bypass_end() so that bypassing attempts
can't slip inbetween.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
blk-mq uses a percpu_counter to keep track of how many usages are in
flight. The percpu_counter is drained while freezing to ensure that
no usage is left in-flight after freezing is complete.
blk_mq_queue_enter/exit() and blk_mq_[un]freeze_queue() implement this
per-cpu gating mechanism; unfortunately, it contains a subtle bug -
smp_wmb() in blk_mq_queue_enter() doesn't prevent prevent the cpu from
fetching @q->bypass_depth before incrementing @q->mq_usage_counter and
if freezing happens inbetween the caller can slip through and freezing
can be complete while there are active users.
Use smp_mb() instead so that bypass_depth and mq_usage_counter
modifications and tests are properly interlocked.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull ARM fixes from Russell King:
"Another round of ARM fixes. The largest change here is the L2 changes
to work around problems for the Armada 37x/380 devices, where most of
the size comes down to comments rather than code.
The other significant fix here is for the ptrace code, to ensure that
rewritten syscalls work as intended. This was pointed out by Kees
Cook, but Will Deacon reworked the patch to be more elegant.
The remainder are fairly trivial changes"
* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
ARM: 8087/1: ptrace: reload syscall number after secure_computing() check
ARM: 8086/1: Set memblock limit for nommu
ARM: 8085/1: sa1100: collie: add top boot mtd partition
ARM: 8084/1: sa1100: collie: revert back to cfi_probe
ARM: 8080/1: mcpm.h: remove unused variable declaration
ARM: 8076/1: mm: add support for HW coherent systems in PL310 cache
Note that I don't maintain Documentation/ABI/,
Documentation/devicetree/, or the language translation files.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On the syscall tracing path, we call out to secure_computing() to allow
seccomp to check the syscall number being attempted. As part of this, a
SIGTRAP may be sent to the tracer and the syscall could be re-written by
a subsequent SET_SYSCALL ptrace request. Unfortunately, this new syscall
is ignored by the current code unless TIF_SYSCALL_TRACE is also set on
the current thread.
This patch slightly reworks the enter path of the syscall tracing code
so that we always reload the syscall number from
current_thread_info()->syscall after the potential ptrace traps.
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit 1c2f87c (ARM: 8025/1: Get rid of meminfo) changed find_limits
to use memblock_get_current_limit for calculating the max_low pfn.
nommu targets never actually set a limit on memblock though which
means memblock_get_current_limit will just return the default
value. Set the memblock_limit to be the end of DDR to make sure
bounds are calculated correctly.
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The CFI mapping is now perfect so we can expose the top block, read only.
There isn't much to read, though, just the sharpsl_params values.
Signed-off-by: Andrea Adami <andrea.adami@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reverts commit d26b17edaf
ARM: sa1100: collie.c: fall back to jedec_probe flash detection
Unfortunately the detection was challenged on the defective unit used for tests:
one of the NOR chips did not respond to the CFI query.
Moreover that bad device needed extra delays on erase-suspend/resume cycles.
Tested personally on 3 different units and with feedback of two other users.
Signed-off-by: Andrea Adami <andrea.adami@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The sync_phys variable has been replaced by link time computation in
mcpm_head.S before the code was submitted upstream.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When a PL310 cache is used on a system that provides hardware
coherency, the outer cache sync operation is useless, and can be
skipped. Moreover, on some systems, it is harmful as it causes
deadlocks between the Marvell coherency mechanism, the Marvell PCIe
controller and the Cortex-A9.
To avoid this, this commit introduces a new Device Tree property
'arm,io-coherent' for the L2 cache controller node, valid only for the
PL310 cache. It identifies the usage of the PL310 cache in an I/O
coherent configuration. Internally, it makes the driver disable the
outer cache sync operation.
Note that technically speaking, a fully coherent system wouldn't
require any of the other .outer_cache operations. However, in
practice, when booting secondary CPUs, these are not yet coherent, and
therefore a set of cache maintenance operations are necessary at this
point. This explains why we keep the other .outer_cache operations and
only ->sync is disabled.
While in theory any write to a PL310 register could cause the
deadlock, in practice, disabling ->sync is sufficient to workaround
the deadlock, since the other cache maintenance operations are only
used in very specific situations.
Contrary to previous versions of this patch, this new version does not
simply NULL-ify the ->sync member, because the l2c_init_data
structures are now 'const' and therefore cannot be modified, which is
a good thing. Therefore, this patch introduces a separate
l2c_init_data instance, called of_l2c310_coherent_data.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pull spi fixes from Mark Brown:
"A few driver specific fixes, the biggest one being a fix for the newly
added Qualcomm SPI controller driver to make it not use its internal
chip select due to hardware bugs, replacing it with GPIOs"
* tag 'spi-v3.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: qup: Remove chip select function
spi: qup: Fix order of spi_register_master
spi: sh-sci: fix use-after-free in sh_sci_spi_remove()
spi/pxa2xx: fix incorrect SW mode chipselect setting for BayTrail LPSS SPI
Pull regulator fixes from Mark Brown:
"Several driver specific fixes here, the palmas fixes being especially
important for a range of boards - the recent updates to support new
devices have introduced several regressions"
* tag 'regulator-v3.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: tps65218: Correct the the config register for LDO1
regulator: tps65218: Add the missing of_node assignment in probe
regulator: palmas: fix typo in enable_reg calculation
regulator: bcm590xx: fix vbus name
regulator: palmas: Fix SMPS enable/disable/is_enabled
Pull SCSI target fixes from Nicholas Bellinger:
"Mostly minor fixes this time around. The highlights include:
- iscsi-target CHAP authentication fixes to enforce explicit key
values (Tejas Vaykole + rahul.rane)
- fix a long-standing OOPs in target-core when a alua configfs
attribute is accessed after port symlink has been removed.
(Sebastian Herbszt)
- fix a v3.10.y iscsi-target regression causing the login reject
status class/detail to be ignored (Christoph Vu-Brugier)
- fix a v3.10.y iscsi-target regression to avoid rejecting an
existing ITT during Data-Out when data-direction is wrong (Santosh
Kulkarni + Arshad Hussain)
- fix a iscsi-target related shutdown deadlock on UP kernels (Mikulas
Patocka)
- fix a v3.16-rc1 build issue with vhost-scsi + !CONFIG_NET (MST)"
* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
iscsi-target: fix iscsit_del_np deadlock on unload
iovec: move memcpy_from/toiovecend to lib/iovec.c
iscsi-target: Avoid rejecting incorrect ITT for Data-Out
tcm_loop: Fix memory leak in tcm_loop_submission_work error path
iscsi-target: Explicily clear login response PDU in exception path
target: Fix left-over se_lun->lun_sep pointer OOPs
iscsi-target; Enforce 1024 byte maximum for CHAP_C key value
iscsi-target: Convert chap_server_compute_md5 to use kstrtoul
Now that explicit invocation of percpu_ref_exit() is necessary to free
the percpu counter, we can implement percpu_ref_reinit() which
reinitializes a released percpu_ref. This can be used implement
scalable gating switch which can be drained and then re-opened without
worrying about memory allocation failures.
percpu_ref_is_zero() is added to be used in a sanity check in
percpu_ref_exit(). As this function will be useful for other purposes
too, make it a public interface.
v2: Use smp_read_barrier_depends() instead of smp_load_acquire(). We
only need data dep barrier and smp_load_acquire() is stronger and
heavier on some archs. Spotted by Lai Jiangshan.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Currently, a percpu_ref undoes percpu_ref_init() automatically by
freeing the allocated percpu area when the percpu_ref is killed.
While seemingly convenient, this has the following niggles.
* It's impossible to re-init a released reference counter without
going through re-allocation.
* In the similar vein, it's impossible to initialize a percpu_ref
count with static percpu variables.
* We need and have an explicit destructor anyway for failure paths -
percpu_ref_cancel_init().
This patch removes the automatic percpu counter freeing in
percpu_ref_kill_rcu() and repurposes percpu_ref_cancel_init() into a
generic destructor now named percpu_ref_exit(). percpu_ref_destroy()
is considered but it gets confusing with percpu_ref_kill() while
"exit" clearly indicates that it's the counterpart of
percpu_ref_init().
All percpu_ref_cancel_init() users are updated to invoke
percpu_ref_exit() instead and explicit percpu_ref_exit() calls are
added to the destruction path of all percpu_ref users.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Cc: Li Zefan <lizefan@huawei.com>
percpu_ref->pcpu_count is a percpu pointer with a status flag in its
lowest bit. As such, it always goes through arithmetic operations
which is very cumbersome to do on a pointer. It has to be first
casted to unsigned long and then back.
Let's just make the field unsigned long so that we can skip the first
casts. While at it, rename it to pcpu_counter_ptr to clarify that
it's a pointer value.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Gu Zheng
Tejun Heo
Jens Axboe
Linus Torvalds
Randy Dunlap
Dan Carpenter
Will Deacon
Laura Abbott
Andrea Adami
Nicolas Pitre
Thomas Petazzoni
Mark Brown