Pull networking updates from David Miller:
"Here is my initial pull request for the networking subsystem during
this merge window:
1) Support for ESN in AH (RFC 4302) from Fan Du.
2) Add full kernel doc for ethtool command structures, from Ben
Hutchings.
3) Add BCM7xxx PHY driver, from Florian Fainelli.
4) Export computed TCP rate information in netlink socket dumps, from
Eric Dumazet.
5) Allow IPSEC SA to be dumped partially using a filter, from Nicolas
Dichtel.
6) Convert many drivers to pci_enable_msix_range(), from Alexander
Gordeev.
7) Record SKB timestamps more efficiently, from Eric Dumazet.
8) Switch to microsecond resolution for TCP round trip times, also
from Eric Dumazet.
9) Clean up and fix 6lowpan fragmentation handling by making use of
the existing inet_frag api for it's implementation.
10) Add TX grant mapping to xen-netback driver, from Zoltan Kiss.
11) Auto size SKB lengths when composing netlink messages based upon
past message sizes used, from Eric Dumazet.
12) qdisc dumps can take a long time, add a cond_resched(), From Eric
Dumazet.
13) Sanitize netpoll core and drivers wrt. SKB handling semantics.
Get rid of never-used-in-tree netpoll RX handling. From Eric W
Biederman.
14) Support inter-address-family and namespace changing in VTI tunnel
driver(s). From Steffen Klassert.
15) Add Altera TSE driver, from Vince Bridgers.
16) Optimizing csum_replace2() so that it doesn't adjust the checksum
by checksumming the entire header, from Eric Dumazet.
17) Expand BPF internal implementation for faster interpreting, more
direct translations into JIT'd code, and much cleaner uses of BPF
filtering in non-socket ocntexts. From Daniel Borkmann and Alexei
Starovoitov"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1976 commits)
netpoll: Use skb_irq_freeable to make zap_completion_queue safe.
net: Add a test to see if a skb is freeable in irq context
qlcnic: Fix build failure due to undefined reference to `vxlan_get_rx_port'
net: ptp: move PTP classifier in its own file
net: sxgbe: make "core_ops" static
net: sxgbe: fix logical vs bitwise operation
net: sxgbe: sxgbe_mdio_register() frees the bus
Call efx_set_channels() before efx->type->dimension_resources()
xen-netback: disable rogue vif in kthread context
net/mlx4: Set proper build dependancy with vxlan
be2net: fix build dependency on VxLAN
mac802154: make csma/cca parameters per-wpan
mac802154: allow only one WPAN to be up at any given time
net: filter: minor: fix kdoc in __sk_run_filter
netlink: don't compare the nul-termination in nla_strcmp
can: c_can: Avoid led toggling for every packet.
can: c_can: Simplify TX interrupt cleanup
can: c_can: Store dlc private
can: c_can: Reduce register access
can: c_can: Make the code readable
...
Pull core block layer updates from Jens Axboe:
"This is the pull request for the core block IO bits for the 3.15
kernel. It's a smaller round this time, it contains:
- Various little blk-mq fixes and additions from Christoph and
myself.
- Cleanup of the IPI usage from the block layer, and associated
helper code. From Frederic Weisbecker and Jan Kara.
- Duplicate code cleanup in bio-integrity from Gu Zheng. This will
give you a merge conflict, but that should be easy to resolve.
- blk-mq notify spinlock fix for RT from Mike Galbraith.
- A blktrace partial accounting bug fix from Roman Pen.
- Missing REQ_SYNC detection fix for blk-mq from Shaohua Li"
* 'for-3.15/core' of git://git.kernel.dk/linux-block: (25 commits)
blk-mq: add REQ_SYNC early
rt,blk,mq: Make blk_mq_cpu_notify_lock a raw spinlock
blk-mq: support partial I/O completions
blk-mq: merge blk_mq_insert_request and blk_mq_run_request
blk-mq: remove blk_mq_alloc_rq
blk-mq: don't dump CPU -> hw queue map on driver load
blk-mq: fix wrong usage of hctx->state vs hctx->flags
blk-mq: allow blk_mq_init_commands() to return failure
block: remove old blk_iopoll_enabled variable
blktrace: fix accounting of partially completed requests
smp: Rename __smp_call_function_single() to smp_call_function_single_async()
smp: Remove wait argument from __smp_call_function_single()
watchdog: Simplify a little the IPI call
smp: Move __smp_call_function_single() below its safe version
smp: Consolidate the various smp_call_function_single() declensions
smp: Teach __smp_call_function_single() to check for offline cpus
smp: Remove unused list_head from csd
smp: Iterate functions through llist_for_each_entry_safe()
block: Stop abusing rq->csd.list in blk-softirq
block: Remove useless IPI struct initialization
...
Conflicts:
Documentation/devicetree/bindings/net/micrel-ks8851.txt
net/core/netpoll.c
The net/core/netpoll.c conflict is a bug fix in 'net' happening
to code which is completely removed in 'net-next'.
In micrel-ks8851.txt we simply have overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
Add REQ_SYNC early, so rq_dispatched[] in blk_mq_rq_ctx_init
is set correctly.
Signed-off-by: Shaohua Li<shli@fusionio.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Add a new blk_mq_end_io_partial function to partially complete requests
as needed by the SCSI layer. We do this by reusing blk_update_request
to advance the bio instead of having a simplified version of it in
the blk-mq code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
It's almost identical to blk_mq_insert_request, so fold the two into one
slightly more generic function by making the flush special case a bit
smarted.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
There's only one caller, which is a straight wrapper and fits the naming
scheme of the related functions a lot better.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Commit 7982e90c3a ("block: fix q->flush_rq NULL pointer crash on
dm-mpath flush") moved an allocation to blk_init_allocated_queue(), but
neglected to free that allocation on the error paths that follow.
Signed-off-by: Dave Jones <davej@fedoraproject.org>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that we are out of initial debug/bringup mode, remove
the verbose dump of the mapping table.
Provide the mapping table in sysfs, under the hardware queue
directory, in the cpu_list file.
Signed-off-by: Jens Axboe <axboe@fb.com>
BLK_MQ_F_* flags are for hctx->flags, and are non-atomic and
set at registration time. BLK_MQ_S_* flags are dynamic and
atomic, and are accessed through hctx->state.
Some of the BLK_MQ_S_STOPPED uses were wrong. Additionally,
the header file should not use a bit shift for the _S_ flags,
as they are done through the set/test_bit functions.
Signed-off-by: Jens Axboe <axboe@fb.com>
Replace the bh safe variant with the hard irq safe variant.
We need a hard irq safe variant to deal with netpoll transmitting
packets from hard irq context, and we need it in most if not all of
the places using the bh safe variant.
Except on 32bit uni-processor the code is exactly the same so don't
bother with a bh variant, just have a hard irq safe variant that
everyone can use.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If drivers do dynamic allocation in the hardware command init
path, then we need to be able to handle and return failures.
And if they do allocations or mappings in the init command path,
then we need a cleanup function to free up that space at exit
time. So add blk_mq_free_commands() as the cleanup function.
This is required for the mtip32xx driver conversion to blk-mq.
Signed-off-by: Jens Axboe <axboe@fb.com>
This was a debugging measure to toggle enabled/disabled
when testing. But for real production setups, it's not
safe to toggle this setting without either reloading
drivers of quiescing IO first. Neither of which the toggle
enforces.
Additionally, it makes drivers deal with the conditional
state.
Remove it completely. It's up to the driver whether iopoll
is enabled or not.
Signed-off-by: Jens Axboe <axboe@fb.com>
Commit 18741986 inadvertently changed the rq flush insertion
from a head to a tail insertion. Fix that back up.
Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Add REQ_SYNC early, so rq_dispatched[] in blk_mq_rq_ctx_init
is set correctly.
Signed-off-by: Shaohua Li<shli@fusionio.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
trace_block_rq_complete does not take into account that request can
be partially completed, so we can get the following incorrect output
of blkparser:
C R 232 + 240 [0]
C R 240 + 232 [0]
C R 248 + 224 [0]
C R 256 + 216 [0]
but should be:
C R 232 + 8 [0]
C R 240 + 8 [0]
C R 248 + 8 [0]
C R 256 + 8 [0]
Also, the whole output summary statistics of completed requests and
final throughput will be incorrect.
This patch takes into account real completion size of the request and
fixes wrong completion accounting.
Signed-off-by: Roman Pen <r.peniaev@gmail.com>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@redhat.com>
CC: linux-kernel@vger.kernel.org
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
The name __smp_call_function_single() doesn't tell much about the
properties of this function, especially when compared to
smp_call_function_single().
The comments above the implementation are also misleading. The main
point of this function is actually not to be able to embed the csd
in an object. This is actually a requirement that result from the
purpose of this function which is to raise an IPI asynchronously.
As such it can be called with interrupts disabled. And this feature
comes at the cost of the caller who then needs to serialize the
IPIs on this csd.
Lets rename the function and enhance the comments so that they reflect
these properties.
Suggested-by: Christoph Hellwig <hch@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The main point of calling __smp_call_function_single() is to send
an IPI in a pure asynchronous way. By embedding a csd in an object,
a caller can send the IPI without waiting for a previous one to complete
as is required by smp_call_function_single() for example. As such,
sending this kind of IPI can be safe even when irqs are disabled.
This flexibility comes at the expense of the caller who then needs to
synchronize the csd lifecycle by himself and make sure that IPIs on a
single csd are serialized.
This is how __smp_call_function_single() works when wait = 0 and this
usecase is relevant.
Now there don't seem to be any usecase with wait = 1 that can't be
covered by smp_call_function_single() instead, which is safer. Lets look
at the two possible scenario:
1) The user calls __smp_call_function_single(wait = 1) on a csd embedded
in an object. It looks like a nice and convenient pattern at the first
sight because we can then retrieve the object from the IPI handler easily.
But actually it is a waste of memory space in the object since the csd
can be allocated from the stack by smp_call_function_single(wait = 1)
and the object can be passed an the IPI argument.
Besides that, embedding the csd in an object is more error prone
because the caller must take care of the serialization of the IPIs
for this csd.
2) The user calls __smp_call_function_single(wait = 1) on a csd that
is allocated on the stack. It's ok but smp_call_function_single()
can do it as well and it already takes care of the allocation on the
stack. Again it's more simple and less error prone.
Therefore, using the underscore prepend API version with wait = 1
is a bad pattern and a sign that the caller can do safer and more
simple.
There was a single user of that which has just been converted.
So lets remove this option to discourage further users.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Abusing rq->csd.list for a list of requests to complete is rather ugly.
We use rq->queuelist instead which is much cleaner. It is safe because
queuelist is used by the block layer only for requests waiting to be
submitted to a device. Thus it is unused when irq reports the request IO
is finished.
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Block layer currently abuses rq->csd.list.next for storing fifo_time.
That is a terrible hack and completely unnecessary as well. Union
achieves the same space saving in a cleaner way.
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Add a new blk_mq_end_io_partial function to partially complete requests
as needed by the SCSI layer. We do this by reusing blk_update_request
to advance the bio instead of having a simplified version of it in
the blk-mq code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
It's almost identical to blk_mq_insert_request, so fold the two into one
slightly more generic function by making the flush special case a bit
smarted.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
There's only one caller, which is a straight wrapper and fits the naming
scheme of the related functions a lot better.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
This patch fix spelling typo in Documentation/DocBook.
It is because .html and .xml files are generated by make htmldocs,
I have to fix a typo within the source files.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
(Trivial patch.)
If the code is looking at the RCU-protected pointer itself, but not
dereferencing it, the rcu_dereference() functions can be downgraded to
rcu_access_pointer(). This commit makes this downgrade in blkg_destroy()
and ioc_destroy_icq(), both of which simply compare the RCU-protected
pointer against another pointer with no dereferencing.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@fb.com>
To increase compiler portability there are several macros defined
in <linux/compiler.h> for various gcc __attribute((..)) constructs.
I've made sure gcc these specific were replaced with the right
macro and an #include <linux/compiler.h> was placed where needed.
Signed-off-by: Gideon Israel Dsouza <gidisrael@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull block IO fixes from Jens Axboe:
"Second round of updates and fixes for 3.14-rc2. Most of this stuff
has been queued up for a while. The notable exception is the blk-mq
changes, which are naturally a bit more in flux still.
The pull request contains:
- Two bug fixes for the new immutable vecs, causing crashes with raid
or swap. From Kent.
- Various blk-mq tweaks and fixes from Christoph. A fix for
integrity bio's from Nic.
- A few bcache fixes from Kent and Darrick Wong.
- xen-blk{front,back} fixes from David Vrabel, Matt Rushton, Nicolas
Swenson, and Roger Pau Monne.
- Fix for a vec miscount with integrity vectors from Martin.
- Minor annotations or fixes from Masanari Iida and Rashika Kheria.
- Tweak to null_blk to do more normal FIFO processing of requests
from Shlomo Pongratz.
- Elevator switching bypass fix from Tejun.
- Softlockup in blkdev_issue_discard() fix when !CONFIG_PREEMPT from
me"
* 'for-linus' of git://git.kernel.dk/linux-block: (31 commits)
block: add cond_resched() to potentially long running ioctl discard loop
xen-blkback: init persistent_purge_work work_struct
blk-mq: pair blk_mq_start_request / blk_mq_requeue_request
blk-mq: dont assume rq->errors is set when returning an error from ->queue_rq
block: Fix cloning of discard/write same bios
block: Fix type mismatch in ssize_t_blk_mq_tag_sysfs_show
blk-mq: rework flush sequencing logic
null_blk: use blk_complete_request and blk_mq_complete_request
virtio_blk: use blk_mq_complete_request
blk-mq: rework I/O completions
fs: Add prototype declaration to appropriate header file include/linux/bio.h
fs: Mark function as static in fs/bio-integrity.c
block/null_blk: Fix completion processing from LIFO to FIFO
block: Explicitly handle discard/write same segments
block: Fix nr_vecs for inline integrity vectors
blk-mq: Add bio_integrity setup to blk_mq_make_request
blk-mq: initialize sg_reserved_size
blk-mq: handle dma_drain_size
blk-mq: divert __blk_put_request for MQ ops
blk-mq: support at_head inserations for blk_execute_rq
...
When mkfs issues a full device discard and the device only
supports discards of a smallish size, we can loop in
blkdev_issue_discard() for a long time. If preempt isn't enabled,
this can turn into a softlock situation and the kernel will
start complaining.
Add an explicit cond_resched() at the end of the loop to avoid
that.
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
Make sure we have a proper pairing between starting and requeueing
requests. Move the dma drain and REQ_END setup into blk_mq_start_request,
and make sure blk_mq_requeue_request properly undoes them, giving us
a pair of function to prepare and unprepare a request without leaving
side effects.
Together this ensures we always clean up properly after
BLK_MQ_RQ_QUEUE_BUSY returns from ->queue_rq.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
rq->errors never has been part of the communication protocol between drivers
and the block stack and most drivers will not have initialized it.
Return -EIO to upper layers when the driver returns BLK_MQ_RQ_QUEUE_ERROR
unconditionally. If a driver want to return a different error it can easily
do so by returning success after calling blk_mq_end_io itself.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
cppcheck detected following format string mismatch.
[blk-mq-tag.c:201]: (warning) %u in format string (no. 1) requires
'unsigned int' but the argument type is 'int'.
Change "cpu" from int to unsigned int, because the cpu
never become minus value.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Witch to using a preallocated flush_rq for blk-mq similar to what's done
with the old request path. This allows us to set up the request properly
with a tag from the actually allowed range and ->rq_disk as needed by
some drivers. To make life easier we also switch to dynamic allocation
of ->flush_rq for the old path.
This effectively reverts most of
"blk-mq: fix for flush deadlock"
and
"blk-mq: Don't reserve a tag for flush request"
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Rework I/O completions to work more like the old code path. blk_mq_end_io
now stays out of the business of deferring completions to others CPUs
and calling blk_mark_rq_complete. The latter is very important to allow
completing requests that have timed out and thus are already marked completed,
the former allows using the IPI callout even for driver specific completions
instead of having to reimplement them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Immutable biovecs changed the way biovecs are interpreted - drivers no
longer use bi_vcnt, they have to go by bi_iter.bi_size (to allow for
using part of an existing segment without modifying it).
This breaks with discards and write_same bios, since for those bi_size
has nothing to do with segments in the biovec. So for now, we need a
fairly gross hack - we fortunately know that there will never be more
than one segment for the entire request, so we can special case
discard/write_same.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Tested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This patch adds the missing bio_integrity_enabled() +
bio_integrity_prep() setup into blk_mq_make_request()
in order to use DIF protection with scsi-mq.
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Make blk-mq handle the dma_drain_size field the same way as the old request
path.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
__blk_put_request needs to call into the blk-mq code just like
blk_put_request. As we don't have the queue lock in this case both
end up calling the same function.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
This is neede for proper SG_IO operation as well as various uses of
blk_execute_rq from the SCSI midlayer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull SCSI target updates from Nicholas Bellinger:
"The highlights this round include:
- add support for SCSI Referrals (Hannes)
- add support for T10 DIF into target core (nab + mkp)
- add support for T10 DIF emulation in FILEIO + RAMDISK backends (Sagi + nab)
- add support for T10 DIF -> bio_integrity passthrough in IBLOCK backend (nab)
- prep changes to iser-target for >= v3.15 T10 DIF support (Sagi)
- add support for qla2xxx N_Port ID Virtualization - NPIV (Saurav + Quinn)
- allow percpu_ida_alloc() to receive task state bitmask (Kent)
- fix >= v3.12 iscsi-target session reset hung task regression (nab)
- fix >= v3.13 percpu_ref se_lun->lun_ref_active race (nab)
- fix a long-standing network portal creation race (Andy)"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (51 commits)
target: Fix percpu_ref_put race in transport_lun_remove_cmd
target/iscsi: Fix network portal creation race
target: Report bad sector in sense data for DIF errors
iscsi-target: Convert gfp_t parameter to task state bitmask
iscsi-target: Fix connection reset hang with percpu_ida_alloc
percpu_ida: Make percpu_ida_alloc + callers accept task state bitmask
iscsi-target: Pre-allocate more tags to avoid ack starvation
qla2xxx: Configure NPIV fc_vport via tcm_qla2xxx_npiv_make_lport
qla2xxx: Enhancements to enable NPIV support for QLOGIC ISPs with TCM/LIO.
qla2xxx: Fix scsi_host leak on qlt_lport_register callback failure
IB/isert: pass scatterlist instead of cmd to fast_reg_mr routine
IB/isert: Move fastreg descriptor creation to a function
IB/isert: Avoid frwr notation, user fastreg
IB/isert: seperate connection protection domains and dma MRs
tcm_loop: Enable DIF/DIX modes in SCSI host LLD
target/rd: Add DIF protection into rd_execute_rw
target/rd: Add support for protection SGL setup + release
target/rd: Refactor rd_build_device_space + rd_release_device_space
target/file: Add DIF protection support to fd_execute_rw
target/file: Add DIF protection init/format support
...
request_queue bypassing is used to suppress higher-level function of a
request_queue so that they can be switched, reconfigured and shut
down. A request_queue does the followings while bypassing.
* bypasses elevator and io_cq association and queues requests directly
to the FIFO dispatch queue.
* bypasses block cgroup request_list lookup and always uses the root
request_list.
Once confirmed to be bypassing, specific elevator and block cgroup
policy implementations can assume that nothing is in flight for them
and perform various operations which would be dangerous otherwise.
Such confirmation is acheived by short-circuiting all new requests
directly to the dispatch queue and waiting for all the requests which
were issued before to finish. Unfortunately, while the request
allocating and draining sides were properly handled, we forgot to
actually plug the request dispatch path. Even after bypassing mode is
confirmed, if the attached driver tries to fetch a request and the
dispatch queue is empty, __elv_next_request() would invoke the current
elevator's elevator_dispatch_fn() callback. As all in-flight requests
were drained, the elevator wouldn't contain any request but once
bypass is confirmed we don't even know whether the elevator is even
there. It might be in the process of being switched and half torn
down.
Frank Mayhar reports that this actually happened while switching
elevators, leading to an oops.
Let's fix it by making __elv_next_request() avoid invoking the
elevator_dispatch_fn() callback if the queue is bypassing. It already
avoids invoking the callback if the queue is dying. As a dying queue
is guaranteed to be bypassing, we can simply replace blk_queue_dying()
check with blk_queue_bypass().
Reported-by: Frank Mayhar <fmayhar@google.com>
References: http://lkml.kernel.org/g/1390319905.20232.38.camel@bobble.lax.corp.google.com
Cc: stable@vger.kernel.org
Tested-by: Frank Mayhar <fmayhar@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reserving a tag (request) for flush to avoid dead lock is a overkill. A
tag is valuable resource. We can track the number of flush requests and
disallow having too many pending flush requests allocated. With this
patch, blk_mq_alloc_request_pinned() could do a busy nop (but not a dead
loop) if too many pending requests are allocated and new flush request
is allocated. But this should not be a problem, too many pending flush
requests are very rare case.
I verified this can fix the deadlock caused by too many pending flush
requests.
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block IO driver changes from Jens Axboe:
- bcache update from Kent Overstreet.
- two bcache fixes from Nicholas Swenson.
- cciss pci init error fix from Andrew.
- underflow fix in the parallel IDE pg_write code from Dan Carpenter.
I'm sure the 1 (or 0) users of that are now happy.
- two PCI related fixes for sx8 from Jingoo Han.
- floppy init fix for first block read from Jiri Kosina.
- pktcdvd error return miss fix from Julia Lawall.
- removal of IRQF_SHARED from the SEGA Dreamcast CD-ROM code from
Michael Opdenacker.
- comment typo fix for the loop driver from Olaf Hering.
- potential oops fix for null_blk from Raghavendra K T.
- two fixes from Sam Bradshaw (Micron) for the mtip32xx driver, fixing
an OOM problem and a problem with handling security locked conditions
* 'for-3.14/drivers' of git://git.kernel.dk/linux-block: (47 commits)
mg_disk: Spelling s/finised/finished/
null_blk: Null pointer deference problem in alloc_page_buffers
mtip32xx: Correctly handle security locked condition
mtip32xx: Make SGL container per-command to eliminate high order dma allocation
drivers/block/loop.c: fix comment typo in loop_config_discard
drivers/block/cciss.c:cciss_init_one(): use proper errnos
drivers/block/paride/pg.c: underflow bug in pg_write()
drivers/block/sx8.c: remove unnecessary pci_set_drvdata()
drivers/block/sx8.c: use module_pci_driver()
floppy: bail out in open() if drive is not responding to block0 read
bcache: Fix auxiliary search trees for key size > cacheline size
bcache: Don't return -EINTR when insert finished
bcache: Improve bucket_prio() calculation
bcache: Add bch_bkey_equal_header()
bcache: update bch_bkey_try_merge
bcache: Move insert_fixup() to btree_keys_ops
bcache: Convert sorting to btree_keys
bcache: Convert debug code to btree_keys
bcache: Convert btree_iter to struct btree_keys
bcache: Refactor bset_tree sysfs stats
...
Pull core block IO changes from Jens Axboe:
"The major piece in here is the immutable bio_ve series from Kent, the
rest is fairly minor. It was supposed to go in last round, but
various issues pushed it to this release instead. The pull request
contains:
- Various smaller blk-mq fixes from different folks. Nothing major
here, just minor fixes and cleanups.
- Fix for a memory leak in the error path in the block ioctl code
from Christian Engelmayer.
- Header export fix from CaiZhiyong.
- Finally the immutable biovec changes from Kent Overstreet. This
enables some nice future work on making arbitrarily sized bios
possible, and splitting more efficient. Related fixes to immutable
bio_vecs:
- dm-cache immutable fixup from Mike Snitzer.
- btrfs immutable fixup from Muthu Kumar.
- bio-integrity fix from Nic Bellinger, which is also going to stable"
* 'for-3.14/core' of git://git.kernel.dk/linux-block: (44 commits)
xtensa: fixup simdisk driver to work with immutable bio_vecs
block/blk-mq-cpu.c: use hotcpu_notifier()
blk-mq: for_each_* macro correctness
block: Fix memory leak in rw_copy_check_uvector() handling
bio-integrity: Fix bio_integrity_verify segment start bug
block: remove unrelated header files and export symbol
blk-mq: uses page->list incorrectly
blk-mq: use __smp_call_function_single directly
btrfs: fix missing increment of bi_remaining
Revert "block: Warn and free bio if bi_end_io is not set"
block: Warn and free bio if bi_end_io is not set
blk-mq: fix initializing request's start time
block: blk-mq: don't export blk_mq_free_queue()
block: blk-mq: make blk_sync_queue support mq
block: blk-mq: support draining mq queue
dm cache: increment bi_remaining when bi_end_io is restored
block: fixup for generic bio chaining
block: Really silence spurious compiler warnings
block: Silence spurious compiler warnings
block: Kill bio_pair_split()
...
Cleaner, reduces text size when cpu hotplug is disabled.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
