This new callback function will be used in the next patch to show
more information about SCSI requests.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NOmar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Commit 25520d55 ("block: Inline blk_integrity in struct gendisk")
introduced blk_integrity_revalidate(), which seems to assume ownership
of the stable pages flag and unilaterally clears it if no blk_integrity
profile is registered:

    if (bi->profile)
            disk->queue->backing_dev_info->capabilities |=
                    BDI_CAP_STABLE_WRITES;
    else
            disk->queue->backing_dev_info->capabilities &=
                    ~BDI_CAP_STABLE_WRITES;

It's called from revalidate_disk() and rescan_partitions(), making it
impossible to enable stable pages for drivers that support partitions
and don't use blk_integrity: while the call in revalidate_disk() can be
trivially worked around (see zram, which doesn't support partitions and
hence gets away with zram_revalidate_disk()), rescan_partitions() can
be triggered from userspace at any time.  This breaks rbd, where the
ceph messenger is responsible for generating/verifying CRCs.

Since blk_integrity_{un,}register() "must" be used for (un)registering
the integrity profile with the block layer, move BDI_CAP_STABLE_WRITES
setting there.  This way drivers that call blk_integrity_register() and
use integrity infrastructure won't interfere with drivers that don't
but still want stable pages.

Fixes: 25520d55 ("block: Inline blk_integrity in struct gendisk")
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 4.4+, needs backporting
Tested-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

target transport:
----------------------
There are cases when there is a need to abort in-progress target
operations (writedata) so that controller termination or errors can
clean up. That can't happen currently as the abort is another target
op type, so it can't be used till the running one finishes (and it may
not).  Solve by removing the abort op type and creating a separate
downcall from the transport to the lldd to request an io to be aborted.

The transport will abort ios on queue teardown or io errors. In general
the transport tries to call the lldd abort only when the io state is
idle. Meaning: ops that transmit data (readdata or rsp) will always
finish their transmit (or the lldd will see a state on the
link or initiator port that fails the transmit) and the done call for
the operation will occur. The transport will wait for the op done
upcall before calling the abort function, and as the io is idle, the
io can be cleaned up immediately after the abort call; Similarly, ios
that are not waiting for data or transmitting data must be in the nvmet
layer being processed. The transport will wait for the nvmet layer
completion before calling the abort function, and as the io is idle,
the io can be cleaned up immediately after the abort call; As for ops
that are waiting for data (writedata), they may be outstanding
indefinitely if the lldd doesn't see a condition where the initiatior
port or link is bad. In those cases, the transport will call the abort
function and wait for the lldd's op done upcall for the operation, where
it will then clean up the io.

Additionally, if a lldd receives an ABTS and matches it to an outstanding
request in the transport, A new new transport upcall was created to abort
the outstanding request in the transport. The transport expects any
outstanding op call (readdata or writedata) will completed by the lldd and
the operation upcall made. The transport doesn't act on the reported
abort (e.g. clean up the io) until an op done upcall occurs, a new op is
attempted, or the nvmet layer completes the io processing.

fcloop:
----------------------
Updated to support the new target apis.
On fcp io aborts from the initiator, the loopback context is updated to
NULL out the half that has completed. The initiator side is immediately
called after the abort request with an io completion (abort status).
On fcp io aborts from the target, the io is stopped and the initiator side
sees it as an aborted io. Target side ops, perhaps in progress while the
initiator side is done, continue but noop the data movement as there's no
structure on the initiator side to reference.

patch also contains:
----------------------
Revised lpfc to support the new abort api

commonized rsp buffer syncing and nulling of private data based on
calling paths.

errors in op done calls don't take action on the fod. They're bad
operations which implies the fod may be bad.
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

With the advent of the opdone calls changing context, the lldd can no
longer assume that once the op->done call returns for RSP operations
that the request struct is no longer being accessed.

As such, revise the lldd api for a req_release callback that the
transport will call when the job is complete. This will also be used
with abort cases.

Fixed text in api header for change in io complete semantics.

Revised lpfc to support the new req_release api.
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

Two new feature flags were added to control whether upcalls to the
transport result in context switches or stay in the calling context.

NVMET_FCTGTFEAT_CMD_IN_ISR:
  By default, if the flag is not set, the transport assumes the
  lldd is in a non-isr context and in the cpu context it should be
  for the io queue. As such, the cmd handler is called directly in the
  calling context.
  If the flag is set, indicating the upcall is an isr context, the
  transport mandates a transition to a workqueue. The workqueue assigned
  to the queue is used for the context.
NVMET_FCTGTFEAT_OPDONE_IN_ISR
  By default, if the flag is not set, the transport assumes the
  lldd is in a non-isr context and in the cpu context it should be
  for the io queue. As such, the fcp operation done callback is called
  directly in the calling context.
  If the flag is set, indicating the upcall is an isr context, the
  transport mandates a transition to a workqueue. The workqueue assigned
  to the queue is used for the context.

Updated lpfc for flags
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

This change provides a mechanism to reduce the number of MMIO doorbell
writes for the NVMe driver. When running in a virtualized environment
like QEMU, the cost of an MMIO is quite hefy here. The main idea for
the patch is provide the device two memory location locations:
 1) to store the doorbell values so they can be lookup without the doorbell
    MMIO write
 2) to store an event index.
I believe the doorbell value is obvious, the event index not so much.
Similar to the virtio specification, the virtual device can tell the
driver (guest OS) not to write MMIO unless you are writing past this
value.

FYI: doorbell values are written by the nvme driver (guest OS) and the
event index is written by the virtual device (host OS).

The patch implements a new admin command that will communicate where
these two memory locations reside. If the command fails, the nvme
driver will work as before without any optimizations.

Contributions:
  Eric Northup <digitaleric@google.com>
  Frank Swiderski <fes@google.com>
  Ted Tso <tytso@mit.edu>
  Keith Busch <keith.busch@intel.com>

Just to give an idea on the performance boost with the vendor
extension: Running fio [1], a stock NVMe driver I get about 200K read
IOPs with my vendor patch I get about 1000K read IOPs. This was
running with a null device i.e. the backing device simply returned
success on every read IO request.

[1] Running on a 4 core machine:
  fio --time_based --name=benchmark --runtime=30
  --filename=/dev/nvme0n1 --nrfiles=1 --ioengine=libaio --iodepth=32
  --direct=1 --invalidate=1 --verify=0 --verify_fatal=0 --numjobs=4
  --rw=randread --blocksize=4k --randrepeat=false
Signed-off-by: NRob Nelson <rlnelson@google.com>
[mlin: port for upstream]
Signed-off-by: NMing Lin <mlin@kernel.org>
[koike: updated for upstream]
Signed-off-by: NHelen Koike <helen.koike@collabora.co.uk>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKeith Busch <keith.busch@intel.com>

Fixes an issue where the size of the poll_stat array in request_queue
does not match the size expected by the new size based bucketing for
IO completion polling.

Fixes: 720b8ccc ("blk-mq: Add a polling specific stats function")
Signed-off-by: NStephen Bates <sbates@raithlin.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <Bart.VanAssche@sandisk.com>
Acked-by: NRoger Pau Monné <roger.pau@citrix.com>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

This is for the legacy floppy and ataflop drivers that currently abuse
->errors for this purpose.  It's stashed away in a union to not grow
the struct size, the other fields are either used by modern drivers
for different purposes or the I/O scheduler before queing the I/O
to drivers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

Now that all drivers that call blk_mq_complete_requests have a
->complete callback we can remove the direct call to blk_mq_end_request,
as well as the error argument to blk_mq_complete_request.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NBart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

This passes on the scsi_cmnd result field to users of passthrough
requests.  Currently we abuse req->errors for this purpose, but that
field will go away in its current form.

Note that the old IDE code abuses the errors field in very creative
ways and stores all kinds of different values in it.  I didn't dare
to touch this magic, so the abuses are brought forward 1:1.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NBart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

The function only returns -EIO if rq->errors is non-zero, which is not
very useful and lets a large number of callers ignore the return value.

Just let the callers figure out their error themselves.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NBart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Drop 'parent' argument of bdi_register() and bdi_register_va().  It is
always NULL.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

Now that all backing_dev_info structure are allocated separately, we can
drop some unused functions.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

Now that all bdi structures filesystems use are properly refcounted, we
can remove the SB_I_DYNBDI flag.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

Allocate struct backing_dev_info separately instead of embedding it
inside the superblock. This unifies handling of bdi among users.

CC: Anna Schumaker <anna.schumaker@netapp.com>
CC: linux-nfs@vger.kernel.org
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Acked-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Allocate struct backing_dev_info separately instead of embedding it
inside the superblock. This unifies handling of bdi among users.

CC: Jan Harkes <jaharkes@cs.cmu.edu>
CC: coda@cs.cmu.edu
CC: codalist@coda.cs.cmu.edu
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

MTD already allocates backing_dev_info dynamically. Convert it to use
generic infrastructure for this including proper refcounting. We drop
mtd->backing_dev_info as its only use was to pass mtd_bdi pointer from
one file into another and if we wanted to keep that in a clean way, we'd
have to make mtd hold and drop bdi reference as needed which seems
pointless for passing one global pointer...

CC: David Woodhouse <dwmw2@infradead.org>
CC: Brian Norris <computersforpeace@gmail.com>
CC: linux-mtd@lists.infradead.org
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

Provide helper functions for setting up dynamically allocated
backing_dev_info structures for filesystems and cleaning them up on
superblock destruction.

CC: linux-mtd@lists.infradead.org
CC: linux-nfs@vger.kernel.org
CC: Petr Vandrovec <petr@vandrovec.name>
CC: linux-nilfs@vger.kernel.org
CC: cluster-devel@redhat.com
CC: osd-dev@open-osd.org
CC: codalist@coda.cs.cmu.edu
CC: linux-afs@lists.infradead.org
CC: ecryptfs@vger.kernel.org
CC: linux-cifs@vger.kernel.org
CC: ceph-devel@vger.kernel.org
CC: linux-btrfs@vger.kernel.org
CC: v9fs-developer@lists.sourceforge.net
CC: lustre-devel@lists.lustre.org
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

Add function that registers bdi and takes va_list instead of variable
number of arguments.

Add bdi_alloc() as simple wrapper for NUMA-unaware users allocating BDI.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

Since only a single caller remains, inline blk_rq_set_prio(). Initialize
req->ioprio even if no I/O priority has been set in the bio nor in the
I/O context.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NAdam Manzanares <adam.manzanares@wdc.com>
Tested-by: NAdam Manzanares <adam.manzanares@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Cc: Matias Bjørling <m@bjorling.me>
Signed-off-by: NJens Axboe <axboe@fb.com>

Export this function such that it becomes available to block
drivers.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Cc: Matias Bjørling <m@bjorling.me>
Cc: Adam Manzanares <adam.manzanares@wdc.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

This function is not used anywhere in the kernel.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

Both functions are entirely unused.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

Add complete support for full hierarchical scheduling, with a cgroups
interface. Full hierarchical scheduling is implemented through the
'entity' abstraction: both bfq_queues, i.e., the internal BFQ queues
associated with processes, and groups are represented in general by
entities. Given the bfq_queues associated with the processes belonging
to a given group, the entities representing these queues are sons of
the entity representing the group. At higher levels, if a group, say
G, contains other groups, then the entity representing G is the parent
entity of the entities representing the groups in G.

Hierarchical scheduling is performed as follows: if the timestamps of
a leaf entity (i.e., of a bfq_queue) change, and such a change lets
the entity become the next-to-serve entity for its parent entity, then
the timestamps of the parent entity are recomputed as a function of
the budget of its new next-to-serve leaf entity. If the parent entity
belongs, in its turn, to a group, and its new timestamps let it become
the next-to-serve for its parent entity, then the timestamps of the
latter parent entity are recomputed as well, and so on. When a new
bfq_queue must be set in service, the reverse path is followed: the
next-to-serve highest-level entity is chosen, then its next-to-serve
child entity, and so on, until the next-to-serve leaf entity is
reached, and the bfq_queue that this entity represents is set in
service.

Writeback is accounted for on a per-group basis, i.e., for each group,
the async I/O requests of the processes of the group are enqueued in a
distinct bfq_queue, and the entity associated with this queue is a
child of the entity associated with the group.

Weights can be assigned explicitly to groups and processes through the
cgroups interface, differently from what happens, for single
processes, if the cgroups interface is not used (as explained in the
description of the previous patch). In particular, since each node has
a full scheduler, each group can be assigned its own weight.
Signed-off-by: NFabio Checconi <fchecconi@gmail.com>
Signed-off-by: NPaolo Valente <paolo.valente@linaro.org>
Signed-off-by: NArianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Target initialization has two responsibilities: creating the target
partition and instantiating the target. This patch enables to create a
factory partition (e.g., do not trigger recovery on the given target).
This is useful for target development and for being able to restore the
device state at any moment in time without requiring a full-device
erase.
Signed-off-by: NJavier González <javier@cnexlabs.com>
Signed-off-by: NMatias Bjørling <matias@cnexlabs.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

According to the OCSSD 1.2 specification, the 0x200 hint enables the
media scrambler for the read/write opcode, providing that the controller
has been correctly configured by the firmware. Rename the macro to
represent this meaning.
Signed-off-by: NJavier González <javier@cnexlabs.com>
Signed-off-by: NMatias Bjørling <matias@cnexlabs.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Until now erases have been submitted as synchronous commands through a
dedicated erase function. In order to enable targets implementing
asynchronous erases, refactor the erase path so that it uses the normal
async I/O submission functions. If a target requires sync I/O, it can
implement it internally. Also, adapt rrpc to use the new erase path.
Signed-off-by: NJavier González <javier@cnexlabs.com>
Fixed spelling error.
Signed-off-by: NMatias Bjørling <matias@cnexlabs.com>
Signed-off-by: NMatias Bjørling <matias@cnexlabs.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Currently, this callback is called right after put_request() and has no
distinguishable purpose. Instead, let's call it before put_request() as
soon as I/O has completed on the request, before we account it in
blk-stat. With this, Kyber can enable stats when it sees a latency
outlier and make sure the outlier gets accounted.
Signed-off-by: NOmar Sandoval <osandov@fb.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

blk_mq_finish_request() is required for schedulers that define their own
put_request(). blk_mq_run_hw_queue() is required for schedulers that
hold back requests to be run later.
Signed-off-by: NOmar Sandoval <osandov@fb.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

This operation supports the use case of limiting the number of bits that
can be allocated for a given operation. Rather than setting aside some
bits at the end of the bitmap, we can set aside bits in each word of the
bitmap. This means we can keep the allocation hints spread out and
support sbitmap_resize() nicely at the cost of lower granularity for the
allowed depth.
Signed-off-by: NOmar Sandoval <osandov@fb.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

This drivers was added in 2008, but as far as a I can tell we never had a
single platform that actually registered resources for the platform driver.

It's also been unmaintained for a long time and apparently has a ATA mode
that can be driven using the IDE/libata subsystem.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Now that we use the proper REQ_OP_WRITE_ZEROES operation everywhere we can
kill this hack.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

This avoids fallbacks to explicit zeroing in (__)blkdev_issue_zeroout if
the caller doesn't want them.

Also clean up the convoluted check for the return condition that this
new flag is added to.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

If this flag is set logical provisioning capable device should
release space for the zeroed blocks if possible, if it is not set
devices should keep the blocks anchored.

Also remove an out of sync kerneldoc comment for a static function
that would have become even more out of data with this change.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Turn the existing discard flag into a new BLKDEV_ZERO_UNMAP flag with
similar semantics, but without referring to diѕcard.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Copy & paste from the REQ_OP_WRITE_SAME code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Make life easy for implementations that needs to send a data buffer
to the device (e.g. SCSI) by numbering it as a data out command.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Schedulers need to be informed when a hardware queue is added or removed
at runtime so they can allocate/free per-hardware queue data. So,
replace the blk_mq_sched_init_hctx_data() helper, which only makes sense
at init time, with .init_hctx() and .exit_hctx() hooks.
Signed-off-by: NOmar Sandoval <osandov@fb.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

To improve scalability, if hardware queues are shared, restart
a single hardware queue in round-robin fashion. Rename
blk_mq_sched_restart_queues() to reflect the new semantics.
Remove blk_mq_sched_mark_restart_queue() because this function
has no callers. Remove flag QUEUE_FLAG_RESTART because this
patch removes the code that uses this flag.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>