There are only two callers of blk_rq_map_sg/__blk_rq_map_sg that set
the dma_pad value in the queue.  Move the handling into those callers
instead of burdening the common code, and move the ->extra_len field
from struct request to struct scsi_cmnd.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

There's an issue with how sense requests are handled in IDE. If ide-cd
encounters an error, it queues a sense request. With how IDE request
handling is done, this is the next request we need to handle. But it's
impossible to guarantee this, as another request could come in between
the sense being queued, and ->queue_rq() being run and handling it. If
that request ALSO fails, then we attempt to doubly queue the single
sense request we have.

Since we only support one active request at the time, defer request
processing when a sense request is queued.

Fixes: 600335205b8d "ide: convert to blk-mq"
Reported-by: He Zhe <zhe.he@windriver.com>
Tested-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

The initial patch cleared this for all requests, which is wrong
since internal uses can't have this cleared as that's what they
are using to pass data. The fix moved the initialization to the
mq_ops->initialize_rq_fn(), but that's only a partial fix since
it only catches uses from blk_get_request(), not requests coming
from the file system.

Keep the non-fs initialization, and add the IDE entry clear
IFF RQF_DONTPREP isn't set and it's a passthrough request.

Fixes: d16a67667c61 ("ide: don't clear special on ide_queue_rq() entry")
Fixes: 22ce0a7ccf23 ("ide: don't use req->special")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We can't use RQF_DONTPREP to see if we should clear ->special,
as someone could have set that while inserting the request. Make
sure we clear it in our ->initialize_rq_fn() helper instead.

Fixes: 22ce0a7ccf23 ("ide: don't use req->special")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Just replace it with a field of the same name in struct ide_req.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

The return value is just used as a binary yes/no decision, so switch
it to a bool instead of the old BLKPREP_* values returned as an int.

Also clean up a few related comments.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ide-disk and ide-cd tested as working just fine, ide-tape and
ide-floppy haven't. But the latter don't require changes, so they
should work without issue.

Add helper function to insert a request from a work queue, since we
cannot invoke the blk-mq request insertion from IRQ context.

Cc: David Miller <davem@davemloft.net>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Variable queue_run_ms is not being used and is redundant and hence can
be removed. Removing this also means that variable left can also be
removed.

Cleans up clang warning:
warning: variable ‘queue_run_ms’ set but not used [-Wunused-but-set-variable]

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ide_timer_expiry() disables interrupt at function entry when acquiring
hwif->lock. Before disabling the device interrupt it unlocks hwif->lock,
but interrupts stay disabled. After the call to disable_irq() interrupts
are disabled again, which is a pointless exercise.

After the device irq handler has been invoked with interrupts disabled,
hwif->lock is acquired again with spin_lock_irq() because the device irq
handler might have reenabled interrupts. This is not documented and
confusing for the casual reader.

Remove the redundant local_irq_disable() and add a comment which explains
why hwif->lock has to be reacquired with spin_lock_irq().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-ide@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>