generic_make_request has always been very confusingly misnamed, so rename
it to submit_bio_noacct to make it clear that it is submit_bio minus
accounting and a few checks.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The make_request_fn is a little weird in that it sits directly in
struct request_queue instead of an operation vector. Replace it with
a block_device_operations method called submit_bio (which describes much
better what it does). Also remove the request_queue argument to it, as
the queue can be derived pretty trivially from the bio.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The queue can be trivially derived from the bio, so pass one less
argument.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk-mq budget is abstract from scsi's device queue depth, and it is
always per-request-queue instead of hctx.
It can be quite absurd to get a budget from one hctx, then dequeue a
request from scheduler queue, and this request may not belong to this
hctx, at least for bfq and deadline.
So fix the mess and always pass request queue to get/put budget
callback.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Baolin Wang <baolin.wang7@gmail.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Baolin Wang <baolin.wang7@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Just check for a non-NULL elevator directly to make the code more clear.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blkcg_bio_issue_check is a giant inline function that does three entirely
different things. Factor out the blk-cgroup related bio initalization
into a new helper, and the open code the sequence in the only caller,
relying on the fact that all the actual functionality is stubbed out for
non-cgroup builds.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The only thing in blkcg_bio_issue_check that needs to be under
rcu_read_lock is blk_throtl_bio, so move the locking there.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This is purely a sanity check for grave programming errors. Remove it
to simplify further work in this area.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
bio_associate_blkg_from_page is a special purpose helper for swap bios
that doesn't need access to bio internals. Move it to the swap code
instead of having it in bio.c.
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
bio_disassociate_blkg has two callers, of which one immediately assigns
a new value to >bi_blkg. Just open code the function in the two callers.
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently blk-mq does not report any event when two requests get merged
in the elevator. This then results in difficult to understand sequence
of events like:
...
8,0 34 1579 0.608765271 2718 I WS 215023504 + 40 [dbench]
8,0 34 1584 0.609184613 2719 A WS 215023544 + 56 <- (8,4) 2160568
8,0 34 1585 0.609184850 2719 Q WS 215023544 + 56 [dbench]
8,0 34 1586 0.609188524 2719 G WS 215023544 + 56 [dbench]
8,0 3 602 0.609684162 773 D WS 215023504 + 96 [kworker/3:1H]
8,0 34 1591 0.609843593 0 C WS 215023504 + 96 [0]
and you can only guess (after quite some headscratching since the above
excerpt is intermixed with a lot of other IO) that request 215023544+56
got merged to request 215023504+40. Provide proper event for request
merging like we used to do in the legacy block layer.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the struct block_device definition together with most of the
block layer definitions, as it has nothing to do with the rest of fs.h.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Large part of bio.h, blkdev.h and genhd.h are under ifdef CONFIG_BLOCK
for no good reason. Only stub out function that are called from
code that is not dependent on CONFIG_BLOCK and leave the harmless
other declarations around.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the !CONFIG_BLOCK stub to the same place as the non-stub
declaration.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move most of the block related definition out of fs.h into more suitable
headers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Just use IS_ENABLED instead of providing a stub for !CONFIG_BLOCK.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No one calls these functions without CONFIG_BLOCK, so don't bother
stubbing them out.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
These are not defined anywhere, and contrary to the comments we really
do not care about out of tree code at all.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We can also thaw non-block file systems. Remove the CONFIG_BLOCK in
sysrq.c after making the prototype available unconditionally.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We were only creating the request_queue debugfs_dir only
for make_request block drivers (multiqueue), but never for
request-based block drivers. We did this as we were only
creating non-blktrace additional debugfs files on that directory
for make_request drivers. However, since blktrace *always* creates
that directory anyway, we special-case the use of that directory
on blktrace. Other than this being an eye-sore, this exposes
request-based block drivers to the same debugfs fragile
race that used to exist with make_request block drivers
where if we start adding files onto that directory we can later
run a race with a double removal of dentries on the directory
if we don't deal with this carefully on blktrace.
Instead, just simplify things by always creating the request_queue
debugfs_dir on request_queue registration. Rename the mutex also to
reflect the fact that this is used outside of the blktrace context.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit dc9edc44de ("block: Fix a blk_exit_rl() regression") merged on
v4.12 moved the work behind blk_release_queue() into a workqueue after a
splat floated around which indicated some work on blk_release_queue()
could sleep in blk_exit_rl(). This splat would be possible when a driver
called blk_put_queue() or blk_cleanup_queue() (which calls blk_put_queue()
as its final call) from an atomic context.
blk_put_queue() decrements the refcount for the request_queue kobject, and
upon reaching 0 blk_release_queue() is called. Although blk_exit_rl() is
now removed through commit db6d995235 ("block: remove request_list code")
on v5.0, we reserve the right to be able to sleep within
blk_release_queue() context.
The last reference for the request_queue must not be called from atomic
context. *When* the last reference to the request_queue reaches 0 varies,
and so let's take the opportunity to document when that is expected to
happen and also document the context of the related calls as best as
possible so we can avoid future issues, and with the hopes that the
synchronous request_queue removal sticks.
We revert back to synchronous request_queue removal because asynchronous
removal creates a regression with expected userspace interaction with
several drivers. An example is when removing the loopback driver, one
uses ioctls from userspace to do so, but upon return and if successful,
one expects the device to be removed. Likewise if one races to add another
device the new one may not be added as it is still being removed. This was
expected behavior before and it now fails as the device is still present
and busy still. Moving to asynchronous request_queue removal could have
broken many scripts which relied on the removal to have been completed if
there was no error. Document this expectation as well so that this
doesn't regress userspace again.
Using asynchronous request_queue removal however has helped us find
other bugs. In the future we can test what could break with this
arrangement by enabling CONFIG_DEBUG_KOBJECT_RELEASE.
While at it, update the docs with the context expectations for the
request_queue / gendisk refcount decrement, and make these
expectations explicit by using might_sleep().
Fixes: dc9edc44de ("block: Fix a blk_exit_rl() regression")
Suggested-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: yu kuai <yukuai3@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This is a variant of blk_mq_complete_request_remote that only completes
the request if it needs to be bounced to another CPU or a softirq. If
the request can be completed locally the function returns false and lets
the driver complete it without requring and indirect function call.
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the call to blk_should_fake_timeout out of blk_mq_complete_request
and into the drivers, skipping call sites that are obvious error
handlers, and remove the now superflous blk_mq_force_complete_rq helper.
This ensures we don't keep injecting errors into completions that just
terminate the Linux request after the hardware has been reset or the
command has been aborted.
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
__blk_complete_request is only called from the blk-mq code, and
duplicates a lot of code from blk-mq.c. Move it there to prepare
for better code sharing and simplifications.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull powerpc fixes from Michael Ellerman:
- One fix for the interrupt rework we did last release which broke
KVM-PR
- Three commits fixing some fallout from the READ_ONCE() changes
interacting badly with our 8xx 16K pages support, which uses a pte_t
that is a structure of 4 actual PTEs
- A cleanup of the 8xx pte_update() to use the newly added pmd_off()
- A fix for a crash when handling an oops if CONFIG_DEBUG_VIRTUAL is
enabled
- A minor fix for the SPU syscall generation
Thanks to Aneesh Kumar K.V, Christian Zigotzky, Christophe Leroy, Mike
Rapoport, Nicholas Piggin.
* tag 'powerpc-5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/8xx: Provide ptep_get() with 16k pages
mm: Allow arches to provide ptep_get()
mm/gup: Use huge_ptep_get() in gup_hugepte()
powerpc/syscalls: Use the number when building SPU syscall table
powerpc/8xx: use pmd_off() to access a PMD entry in pte_update()
powerpc/64s: Fix KVM interrupt using wrong save area
powerpc: Fix kernel crash in show_instructions() w/DEBUG_VIRTUAL
Pull SCSI fixes from James Bottomley:
"One minor fix and two patches reworking the ata dma drain for the
!CONFIG_LIBATA case. The latter is a 5.7 regression fix"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: Wire up ata_scsi_dma_need_drain for SAS HBA drivers
scsi: libata: Provide an ata_scsi_dma_need_drain stub for !CONFIG_ATA
scsi: ufs-bsg: Fix runtime PM imbalance on error
Pull i2c fixes from Wolfram Sang:
- a small collection of remaining API conversion patches (all acked)
which allow to finally remove the deprecated API
- some documentation fixes and a MAINTAINERS addition
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
MAINTAINERS: Add robert and myself as qcom i2c cci maintainers
i2c: smbus: Fix spelling mistake in the comments
Documentation/i2c: SMBus start signal is S not A
i2c: remove deprecated i2c_new_device API
Documentation: media: convert to use i2c_new_client_device()
video: backlight: tosa_lcd: convert to use i2c_new_client_device()
x86/platform/intel-mid: convert to use i2c_new_client_device()
drm: encoder_slave: use new I2C API
drm: encoder_slave: fix refcouting error for modules
Pull tracing fixes from Steven Rostedt:
- Have recordmcount work with > 64K sections (to support LTO)
- kprobe RCU fixes
- Correct a kprobe critical section with missing mutex
- Remove redundant arch_disarm_kprobe() call
- Fix lockup when kretprobe triggers within kprobe_flush_task()
- Fix memory leak in fetch_op_data operations
- Fix sleep in atomic in ftrace trace array sample code
- Free up memory on failure in sample trace array code
- Fix incorrect reporting of function_graph fields in format file
- Fix quote within quote parsing in bootconfig
- Fix return value of bootconfig tool
- Add testcases for bootconfig tool
- Fix maybe uninitialized warning in ftrace pid file code
- Remove unused variable in tracing_iter_reset()
- Fix some typos
* tag 'trace-v5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace: Fix maybe-uninitialized compiler warning
tools/bootconfig: Add testcase for show-command and quotes test
tools/bootconfig: Fix to return 0 if succeeded to show the bootconfig
tools/bootconfig: Fix to use correct quotes for value
proc/bootconfig: Fix to use correct quotes for value
tracing: Remove unused event variable in tracing_iter_reset
tracing/probe: Fix memleak in fetch_op_data operations
trace: Fix typo in allocate_ftrace_ops()'s comment
tracing: Make ftrace packed events have align of 1
sample-trace-array: Remove trace_array 'sample-instance'
sample-trace-array: Fix sleeping function called from invalid context
kretprobe: Prevent triggering kretprobe from within kprobe_flush_task
kprobes: Remove redundant arch_disarm_kprobe() call
kprobes: Fix to protect kick_kprobe_optimizer() by kprobe_mutex
kprobes: Use non RCU traversal APIs on kprobe_tables if possible
kprobes: Suppress the suspicious RCU warning on kprobes
recordmcount: support >64k sections
Pull libnvdimm updates from Dan Williams:
"A feature (papr_scm health retrieval) and a fix (sysfs attribute
visibility) for v5.8.
Vaibhav explains in the merge commit below why missing v5.8 would be
painful and I agreed to try a -rc2 pull because only cosmetics kept
this out of -rc1 and his initial versions were posted in more than
enough time for v5.8 consideration:
'These patches are tied to specific features that were committed to
customers in upcoming distros releases (RHEL and SLES) whose
time-lines are tied to 5.8 kernel release.
Being able to track the health of an nvdimm is critical for our
customers that are running workloads leveraging papr-scm nvdimms.
Missing the 5.8 kernel would mean missing the distro timelines and
shifting forward the availability of this feature in distro kernels
by at least 6 months'
Summary:
- Fix the visibility of the region 'align' attribute.
The new unit tests for region alignment handling caught a corner
case where the alignment cannot be specified if the region is
converted from static to dynamic provisioning at runtime.
- Add support for device health retrieval for the persistent memory
supported by the papr_scm driver.
This includes both the standard sysfs "health flags" that the nfit
persistent memory driver publishes and a mechanism for the ndctl
tool to retrieve a health-command payload"
* tag 'libnvdimm-for-5.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
nvdimm/region: always show the 'align' attribute
powerpc/papr_scm: Implement support for PAPR_PDSM_HEALTH
ndctl/papr_scm,uapi: Add support for PAPR nvdimm specific methods
powerpc/papr_scm: Improve error logging and handling papr_scm_ndctl()
powerpc/papr_scm: Fetch nvdimm health information from PHYP
seq_buf: Export seq_buf_printf
powerpc: Document details on H_SCM_HEALTH hcall
Pull block fixes from Jens Axboe:
- Use import_uuid() where appropriate (Andy)
- bcache fixes (Coly, Mauricio, Zhiqiang)
- blktrace sparse warnings fix (Jan)
- blktrace concurrent setup fix (Luis)
- blkdev_get use-after-free fix (Jason)
- Ensure all blk-mq maps are updated (Weiping)
- Loop invalidate bdev fix (Zheng)
* tag 'block-5.8-2020-06-19' of git://git.kernel.dk/linux-block:
block: make function 'kill_bdev' static
loop: replace kill_bdev with invalidate_bdev
partitions/ldm: Replace uuid_copy() with import_uuid() where it makes sense
block: update hctx map when use multiple maps
blktrace: Avoid sparse warnings when assigning q->blk_trace
blktrace: break out of blktrace setup on concurrent calls
block: Fix use-after-free in blkdev_get()
trace/events/block.h: drop kernel-doc for dropped function parameter
blk-mq: Remove redundant 'return' statement
bcache: pr_info() format clean up in bcache_device_init()
bcache: use delayed kworker fo asynchronous devices registration
bcache: check and adjust logical block size for backing devices
bcache: fix potential deadlock problem in btree_gc_coalesce
Pull libata fixes from Jens Axboe:
"A few minor changes that should go into this release"
* tag 'libata-5.8-2020-06-19' of git://git.kernel.dk/linux-block:
libata: Use per port sync for detach
ata/libata: Fix usage of page address by page_address in ata_scsi_mode_select_xlat function
sata_rcar: handle pm_runtime_get_sync failure cases
Pull ceph fixes from Ilya Dryomov:
"An important follow-up for replica reads support that went into -rc1
and two target_copy() fixups"
* tag 'ceph-for-5.8-rc2' of git://github.com/ceph/ceph-client:
libceph: don't omit used_replica in target_copy()
libceph: don't omit recovery_deletes in target_copy()
libceph: move away from global osd_req_flags
Pull flex-array size helper from Kees Cook:
"During the treewide clean-ups of zero-length "flexible arrays", the
struct_size() helper was heavily used, but it was noticed that many
times it would have been nice to have an additional helper to get the
size of just the flexible array itself.
This need appears to be even more common when cleaning up the 1-byte
array "flexible arrays", so Gustavo implemented it.
I'd love to get this landed early so it can be used during the v5.9
dev cycle to ease the 1-byte array cleanups."
* tag 'overflow-v5.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
overflow.h: Add flex_array_size() helper
All in-tree users have been converted to the new i2c_new_client_device
function, so remove this deprecated one.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Merge non-faulting memory access cleanups from Christoph Hellwig:
"Andrew and I decided to drop the patches implementing your suggested
rename of the probe_kernel_* and probe_user_* helpers from -mm as
there were way to many conflicts.
After -rc1 might be a good time for this as all the conflicts are
resolved now"
This also adds a type safety checking patch on top of the renaming
series to make the subtle behavioral difference between 'get_user()' and
'get_kernel_nofault()' less potentially dangerous and surprising.
* emailed patches from Christoph Hellwig <hch@lst.de>:
maccess: make get_kernel_nofault() check for minimal type compatibility
maccess: rename probe_kernel_address to get_kernel_nofault
maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofault
maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault
Now that we've renamed probe_kernel_address() to get_kernel_nofault()
and made it look and behave more in line with get_user(), some of the
subtle type behavior differences end up being more obvious and possibly
dangerous.
When you do
get_user(val, user_ptr);
the type of the access comes from the "user_ptr" part, and the above
basically acts as
val = *user_ptr;
by design (except, of course, for the fact that the actual dereference
is done with a user access).
Note how in the above case, the type of the end result comes from the
pointer argument, and then the value is cast to the type of 'val' as
part of the assignment.
So the type of the pointer is ultimately the more important type both
for the access itself.
But 'get_kernel_nofault()' may now _look_ similar, but it behaves very
differently. When you do
get_kernel_nofault(val, kernel_ptr);
it behaves like
val = *(typeof(val) *)kernel_ptr;
except, of course, for the fact that the actual dereference is done with
exception handling so that a faulting access is suppressed and returned
as the error code.
But note how different the casting behavior of the two superficially
similar accesses are: one does the actual access in the size of the type
the pointer points to, while the other does the access in the size of
the target, and ignores the pointer type entirely.
Actually changing get_kernel_nofault() to act like get_user() is almost
certainly the right thing to do eventually, but in the meantime this
patch adds logit to at least verify that the pointer type is compatible
with the type of the result.
In many cases, this involves just casting the pointer to 'void *' to
make it obvious that the type of the pointer is not the important part.
It's not how 'get_user()' acts, but at least the behavioral difference
is now obvious and explicit.
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Better describe what this helper does, and match the naming of
copy_from_kernel_nofault.
Also switch the argument order around, so that it acts and looks
like get_user().
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, address spaces in warnings are displayed as '<asn:X>' with
'X' being the address space's arbitrary number.
But since sparse v0.6.0-rc1 (late December 2018), sparse allows you to
define the address spaces using an identifier instead of a number. This
identifier is then directly used in the warnings.
So, use the identifiers '__user', '__iomem', '__percpu' & '__rcu' for
the corresponding address spaces. The default address space, __kernel,
being not displayed in warnings, stays defined as '0'.
With this change, warnings that used to be displayed as:
cast removes address space '<asn:1>' of expression
... void [noderef] <asn:2> *
will now be displayed as:
cast removes address space '__user' of expression
... void [noderef] __iomem *
This also moves the __kernel annotation to be the first one, since it is
quite different from the others because it's the default one, and so:
- it's never displayed
- it's normally not needed, nor in type annotations, nor in cast
between address spaces. The only time it's needed is when it's
combined with a typeof to express "the same type as this one but
without the address space"
- it can't be defined with a name, '0' must be used.
So, it seemed strange to me to have it in the middle of the other
ones.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 130f4caf14 ("libata: Ensure ata_port probe has completed before
detach") may cause system freeze during suspend.
Using async_synchronize_full() in PM callbacks is wrong, since async
callbacks that are already scheduled may wait for not-yet-scheduled
callbacks, causes a circular dependency.
Instead of using big hammer like async_synchronize_full(), use async
cookie to make sure port probe are synced, without affecting other
scheduled PM callbacks.
Fixes: 130f4caf14 ("libata: Ensure ata_port probe has completed before detach")
Suggested-by: John Garry <john.garry@huawei.com>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: John Garry <john.garry@huawei.com>
BugLink: https://bugs.launchpad.net/bugs/1867983
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add flex_array_size() helper for the calculation of the size, in bytes,
of a flexible array member contained within an enclosing structure.
Example of usage:
struct something {
size_t count;
struct foo items[];
};
struct something *instance;
instance = kmalloc(struct_size(instance, items, count), GFP_KERNEL);
instance->count = count;
memcpy(instance->items, src, flex_array_size(instance, items, instance->count));
The helper returns SIZE_MAX on overflow instead of wrapping around.
Additionally replaces parameter "n" with "count" in struct_size() helper
for greater clarity and unification.
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20200609012233.GA3371@embeddedor
Signed-off-by: Kees Cook <keescook@chromium.org>
Ziqian reported lockup when adding retprobe on _raw_spin_lock_irqsave.
My test was also able to trigger lockdep output:
============================================
WARNING: possible recursive locking detected
5.6.0-rc6+ #6 Not tainted
--------------------------------------------
sched-messaging/2767 is trying to acquire lock:
ffffffff9a492798 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_hash_lock+0x52/0xa0
but task is already holding lock:
ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(kretprobe_table_locks[i].lock));
lock(&(kretprobe_table_locks[i].lock));
*** DEADLOCK ***
May be due to missing lock nesting notation
1 lock held by sched-messaging/2767:
#0: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50
stack backtrace:
CPU: 3 PID: 2767 Comm: sched-messaging Not tainted 5.6.0-rc6+ #6
Call Trace:
dump_stack+0x96/0xe0
__lock_acquire.cold.57+0x173/0x2b7
? native_queued_spin_lock_slowpath+0x42b/0x9e0
? lockdep_hardirqs_on+0x590/0x590
? __lock_acquire+0xf63/0x4030
lock_acquire+0x15a/0x3d0
? kretprobe_hash_lock+0x52/0xa0
_raw_spin_lock_irqsave+0x36/0x70
? kretprobe_hash_lock+0x52/0xa0
kretprobe_hash_lock+0x52/0xa0
trampoline_handler+0xf8/0x940
? kprobe_fault_handler+0x380/0x380
? find_held_lock+0x3a/0x1c0
kretprobe_trampoline+0x25/0x50
? lock_acquired+0x392/0xbc0
? _raw_spin_lock_irqsave+0x50/0x70
? __get_valid_kprobe+0x1f0/0x1f0
? _raw_spin_unlock_irqrestore+0x3b/0x40
? finish_task_switch+0x4b9/0x6d0
? __switch_to_asm+0x34/0x70
? __switch_to_asm+0x40/0x70
The code within the kretprobe handler checks for probe reentrancy,
so we won't trigger any _raw_spin_lock_irqsave probe in there.
The problem is in outside kprobe_flush_task, where we call:
kprobe_flush_task
kretprobe_table_lock
raw_spin_lock_irqsave
_raw_spin_lock_irqsave
where _raw_spin_lock_irqsave triggers the kretprobe and installs
kretprobe_trampoline handler on _raw_spin_lock_irqsave return.
The kretprobe_trampoline handler is then executed with already
locked kretprobe_table_locks, and first thing it does is to
lock kretprobe_table_locks ;-) the whole lockup path like:
kprobe_flush_task
kretprobe_table_lock
raw_spin_lock_irqsave
_raw_spin_lock_irqsave ---> probe triggered, kretprobe_trampoline installed
---> kretprobe_table_locks locked
kretprobe_trampoline
trampoline_handler
kretprobe_hash_lock(current, &head, &flags); <--- deadlock
Adding kprobe_busy_begin/end helpers that mark code with fake
probe installed to prevent triggering of another kprobe within
this code.
Using these helpers in kprobe_flush_task, so the probe recursion
protection check is hit and the probe is never set to prevent
above lockup.
Link: http://lkml.kernel.org/r/158927059835.27680.7011202830041561604.stgit@devnote2
Fixes: ef53d9c5e4 ("kprobes: improve kretprobe scalability with hashed locking")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Gustavo A . R . Silva" <gustavoars@kernel.org>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Reported-by: "Ziqian SUN (Zamir)" <zsun@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull networking fixes from David Miller:
1) Don't get per-cpu pointer with preemption enabled in nft_set_pipapo,
fix from Stefano Brivio.
2) Fix memory leak in ctnetlink, from Pablo Neira Ayuso.
3) Multiple definitions of MPTCP_PM_MAX_ADDR, from Geliang Tang.
4) Accidently disabling NAPI in non-error paths of macb_open(), from
Charles Keepax.
5) Fix races between alx_stop and alx_remove, from Zekun Shen.
6) We forget to re-enable SRIOV during resume in bnxt_en driver, from
Michael Chan.
7) Fix memory leak in ipv6_mc_destroy_dev(), from Wang Hai.
8) rxtx stats use wrong index in mvpp2 driver, from Sven Auhagen.
9) Fix memory leak in mptcp_subflow_create_socket error path, from Wei
Yongjun.
10) We should not adjust the TCP window advertised when sending dup acks
in non-SACK mode, because it won't be counted as a dup by the sender
if the window size changes. From Eric Dumazet.
11) Destroy the right number of queues during remove in mvpp2 driver,
from Sven Auhagen.
12) Various WOL and PM fixes to e1000 driver, from Chen Yu, Vaibhav
Gupta, and Arnd Bergmann.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (35 commits)
e1000e: fix unused-function warning
e1000: use generic power management
e1000e: Do not wake up the system via WOL if device wakeup is disabled
lan743x: add MODULE_DEVICE_TABLE for module loading alias
mlxsw: spectrum: Adjust headroom buffers for 8x ports
bareudp: Fixed configuration to avoid having garbage values
mvpp2: remove module bugfix
tcp: grow window for OOO packets only for SACK flows
mptcp: fix memory leak in mptcp_subflow_create_socket()
netfilter: flowtable: Make nf_flow_table_offload_add/del_cb inline
net/sched: act_ct: Make tcf_ct_flow_table_restore_skb inline
net: dsa: sja1105: fix PTP timestamping with large tc-taprio cycles
mvpp2: ethtool rxtx stats fix
MAINTAINERS: switch to my private email for Renesas Ethernet drivers
rocker: fix incorrect error handling in dma_rings_init
test_objagg: Fix potential memory leak in error handling
net: ethernet: mtk-star-emac: simplify interrupt handling
mld: fix memory leak in ipv6_mc_destroy_dev()
bnxt_en: Return from timer if interface is not in open state.
bnxt_en: Fix AER reset logic on 57500 chips.
...
