From d868ca24302e99a0e8a86071ca2c66273edf97d9 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 19 Apr 2009 07:00:42 +0900 Subject: ide-taskfile: don't abuse rq->buffer Impact: rq->buffer usage cleanup ide_raw_taskfile() directly uses rq->buffer to carry pointer to the data buffer. This complicates both block interface and ide backend request handling. Use blk_rq_map_kern() instead and drop special handling for REQ_TYPE_ATA_TASKFILE from ide_map_sg(). Note that REQ_RW setting is moved upwards as blk_rq_map_kern() uses it to initialize bio rw flag. Signed-off-by: Tejun Heo Cc: Jens Axboe --- drivers/ide/ide-io.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'drivers/ide/ide-io.c') diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c index 35dc38d3b2c5..9b9e8b1aae5e 100644 --- a/drivers/ide/ide-io.c +++ b/drivers/ide/ide-io.c @@ -248,10 +248,7 @@ void ide_map_sg(ide_drive_t *drive, struct ide_cmd *cmd) struct scatterlist *sg = hwif->sg_table; struct request *rq = cmd->rq; - if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) { - sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE); - cmd->sg_nents = 1; - } else if (!rq->bio) { + if (!rq->bio) { sg_init_one(sg, rq->data, rq->data_len); cmd->sg_nents = 1; } else -- cgit v1.2.2 From 02e7cf8f848841ca21864ccd019e480b73c323b7 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 19 Apr 2009 07:00:42 +0900 Subject: ide-cd,atapi: use bio for internal commands Impact: unify request data buffer handling rq->data is used mostly to pass kernel buffer through request queue without using bio. There are only a couple of places which still do this in kernel and converting to bio isn't difficult. This patch converts ide-cd and atapi to use bio instead of rq->data for request sense and internal pc commands. With previous change to unify sense request handling, this is relatively easily achieved by adding blk_rq_map_kern() during sense_rq prep and PC issue. If blk_rq_map_kern() fails for sense, the error is deferred till sense issue and aborts the failed command which triggered the sense. Note that this is a slim possibility as sense prep is done on each command issue, so for the above condition to actually trigger, all preps since the last sense issue till the issue of the request which would require a sense should fail. * do_request functions might sleep now. This should be okay as ide request_fn - do_ide_request() - is invoked only from make_request and plug work. Make sure this is the case by adding might_sleep() to do_ide_request(). * Functions which access the read sense data before the sense request is complete now should access bio_data(sense_rq->bio) as the sense buffer might have been copied during blk_rq_map_kern(). * ide-tape updated to map sg. * cdrom_do_block_pc() now doesn't have to deal with REQ_TYPE_ATA_PC special case. Simplified. * tp_ops->output/input_data path dropped from ide_pc_intr(). Signed-off-by: Tejun Heo --- drivers/ide/ide-io.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/ide/ide-io.c') diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c index 9b9e8b1aae5e..3245c2dbda33 100644 --- a/drivers/ide/ide-io.c +++ b/drivers/ide/ide-io.c @@ -481,6 +481,9 @@ void do_ide_request(struct request_queue *q) spin_unlock_irq(q->queue_lock); + /* HLD do_request() callback might sleep, make sure it's okay */ + might_sleep(); + if (ide_lock_host(host, hwif)) goto plug_device_2; -- cgit v1.2.2 From 765139ef5f1a4b1d5cb1f1a7a12de7ee61f6500f Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 19 Apr 2009 07:00:43 +0900 Subject: ide-pm: don't abuse rq->data Impact: cleanup rq->data usage ide-pm uses rq->data to carry pointer to struct request_pm_state through request queue and rq->special is used to carray pointer to local struct ide_cmd, which isn't necessary. Use rq->special for request_pm_state instead and use local ide_cmd in ide_start_power_step(). Signed-off-by: Tejun Heo Cc: Jens Axboe --- drivers/ide/ide-io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/ide/ide-io.c') diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c index 3245c2dbda33..6e3094e22775 100644 --- a/drivers/ide/ide-io.c +++ b/drivers/ide/ide-io.c @@ -368,7 +368,7 @@ static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq) if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) return execute_drive_cmd(drive, rq); else if (blk_pm_request(rq)) { - struct request_pm_state *pm = rq->data; + struct request_pm_state *pm = rq->special; #ifdef DEBUG_PM printk("%s: start_power_step(step: %d)\n", drive->name, pm->pm_step); -- cgit v1.2.2 From 5ad960fe8d0e4f99fe2b8dded45e8251137293c9 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 19 Apr 2009 08:46:03 +0900 Subject: ide: drop rq->data handling from ide_map_sg() Impact: remove code path which is no longer necessary All IDE data transfers now use rq->bio. Simplify ide_map_sg() accordingly. Signed-off-by: Tejun Heo Cc: Jens Axboe --- drivers/ide/ide-io.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'drivers/ide/ide-io.c') diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c index 6e3094e22775..a0309ea661ac 100644 --- a/drivers/ide/ide-io.c +++ b/drivers/ide/ide-io.c @@ -248,11 +248,7 @@ void ide_map_sg(ide_drive_t *drive, struct ide_cmd *cmd) struct scatterlist *sg = hwif->sg_table; struct request *rq = cmd->rq; - if (!rq->bio) { - sg_init_one(sg, rq->data, rq->data_len); - cmd->sg_nents = 1; - } else - cmd->sg_nents = blk_rq_map_sg(drive->queue, rq, sg); + cmd->sg_nents = blk_rq_map_sg(drive->queue, rq, sg); } EXPORT_SYMBOL_GPL(ide_map_sg); -- cgit v1.2.2 From 5b93629b4509c03ffa87a9316412fedf6f58cb37 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 7 May 2009 22:24:38 +0900 Subject: block: implement blk_rq_pos/[cur_]sectors() and convert obvious ones Implement accessors - blk_rq_pos(), blk_rq_sectors() and blk_rq_cur_sectors() which return rq->hard_sector, rq->hard_nr_sectors and rq->hard_cur_sectors respectively and convert direct references of the said fields to the accessors. This is in preparation of request data length handling cleanup. Geert : suggested adding const to struct request * parameter to accessors Sergei : spotted error in patch description [ Impact: cleanup ] Signed-off-by: Tejun Heo Acked-by: Geert Uytterhoeven Acked-by: Stephen Rothwell Tested-by: Grant Likely Acked-by: Grant Likely Ackec-by: Sergei Shtylyov Cc: Bartlomiej Zolnierkiewicz Cc: Borislav Petkov Cc: James Bottomley Signed-off-by: Jens Axboe --- drivers/ide/ide-io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/ide/ide-io.c') diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c index a0309ea661ac..df23bcbd94b4 100644 --- a/drivers/ide/ide-io.c +++ b/drivers/ide/ide-io.c @@ -118,7 +118,7 @@ unsigned int ide_rq_bytes(struct request *rq) if (blk_pc_request(rq)) return rq->data_len; else - return rq->hard_cur_sectors << 9; + return blk_rq_cur_sectors(rq) << 9; } EXPORT_SYMBOL_GPL(ide_rq_bytes); @@ -133,7 +133,7 @@ int ide_complete_rq(ide_drive_t *drive, int error, unsigned int nr_bytes) * and complete the whole request right now */ if (blk_noretry_request(rq) && error <= 0) - nr_bytes = rq->hard_nr_sectors << 9; + nr_bytes = blk_rq_sectors(rq) << 9; rc = ide_end_rq(drive, rq, error, nr_bytes); if (rc == 0) -- cgit v1.2.2 From 9780e2dd8254351f6cbe11304849126b51dbd561 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 7 May 2009 22:24:40 +0900 Subject: ide: convert to rq pos and nr_sectors accessors ide doesn't manipulate request fields anymore and thus all hard and their soft equivalents are always equal. Convert all references to accessors. [ Impact: use pos and nr_sectors accessors ] Signed-off-by: Tejun Heo Acked-by: Bartlomiej Zolnierkiewicz Cc: Borislav Petkov Cc: Sergei Shtylyov Signed-off-by: Jens Axboe --- drivers/ide/ide-io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/ide/ide-io.c') diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c index df23bcbd94b4..59799ca55246 100644 --- a/drivers/ide/ide-io.c +++ b/drivers/ide/ide-io.c @@ -279,7 +279,7 @@ static ide_startstop_t execute_drive_cmd (ide_drive_t *drive, if (cmd) { if (cmd->protocol == ATA_PROT_PIO) { - ide_init_sg_cmd(cmd, rq->nr_sectors << 9); + ide_init_sg_cmd(cmd, blk_rq_sectors(rq) << 9); ide_map_sg(drive, cmd); } @@ -387,7 +387,7 @@ static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq) drv = *(struct ide_driver **)rq->rq_disk->private_data; - return drv->do_request(drive, rq, rq->sector); + return drv->do_request(drive, rq, blk_rq_pos(rq)); } return do_special(drive); kill_rq: -- cgit v1.2.2 From 34b7d2c957199834c474c9d46739265643f4d9c7 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 7 May 2009 22:24:43 +0900 Subject: ide: cleanup rq->data_len usages With recent unification of fields, it's now guaranteed that rq->data_len always equals blk_rq_bytes(). Convert all direct users to accessors. [ Impact: convert direct rq->data_len usages to blk_rq_bytes() ] Signed-off-by: Tejun Heo Acked-by: Bartlomiej Zolnierkiewicz Cc: Borislav Petkov Cc: Sergei Shtylyov Signed-off-by: Jens Axboe --- drivers/ide/ide-io.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/ide/ide-io.c') diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c index 59799ca55246..ca2519d7b994 100644 --- a/drivers/ide/ide-io.c +++ b/drivers/ide/ide-io.c @@ -116,7 +116,7 @@ void ide_complete_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat, u8 err) unsigned int ide_rq_bytes(struct request *rq) { if (blk_pc_request(rq)) - return rq->data_len; + return blk_rq_bytes(rq); else return blk_rq_cur_sectors(rq) << 9; } -- cgit v1.2.2 From 8f6205cd572fece673da0255d74843680f67f879 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 8 May 2009 11:53:59 +0900 Subject: ide: dequeue in-flight request ide generally has single request in flight and tracks it using hwif->rq and all state handlers follow the following convention. * ide_started is returned if the request is in flight. * ide_stopped is returned if the queue needs to be restarted. The request might or might not have been processed fully or partially. * hwif->rq is set to NULL, when an issued request completes. So, dequeueing model can be implemented by dequeueing after fetch, requeueing if hwif->rq isn't NULL on ide_stopped return and doing about the same thing on completion / port unlock paths. These changes can be made in ide-io proper. In addition to the above main changes, the following updates are necessary. * ide-cd shouldn't dequeue a request when issuing REQUEST SENSE for it as the request is already dequeued. * ide-atapi uses request queue as stack when issuing REQUEST SENSE to put the REQUEST SENSE in front of the failed request. This now needs to be done using requeueing. [ Impact: dequeue in-flight request ] Signed-off-by: Tejun Heo Cc: Bartlomiej Zolnierkiewicz Cc: Borislav Petkov Cc: Sergei Shtylyov Signed-off-by: Jens Axboe --- drivers/ide/ide-io.c | 34 +++++++++++++++++++++++++++------- 1 file changed, 27 insertions(+), 7 deletions(-) (limited to 'drivers/ide/ide-io.c') diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c index ca2519d7b994..abda7337b3f4 100644 --- a/drivers/ide/ide-io.c +++ b/drivers/ide/ide-io.c @@ -487,10 +487,10 @@ void do_ide_request(struct request_queue *q) if (!ide_lock_port(hwif)) { ide_hwif_t *prev_port; + + WARN_ON_ONCE(hwif->rq); repeat: prev_port = hwif->host->cur_port; - hwif->rq = NULL; - if (drive->dev_flags & IDE_DFLAG_SLEEPING && time_after(drive->sleep, jiffies)) { ide_unlock_port(hwif); @@ -519,7 +519,12 @@ repeat: * we know that the queue isn't empty, but this can happen * if the q->prep_rq_fn() decides to kill a request */ - rq = elv_next_request(drive->queue); + if (!rq) { + rq = elv_next_request(drive->queue); + if (rq) + blkdev_dequeue_request(rq); + } + spin_unlock_irq(q->queue_lock); spin_lock_irq(&hwif->lock); @@ -555,8 +560,11 @@ repeat: startstop = start_request(drive, rq); spin_lock_irq(&hwif->lock); - if (startstop == ide_stopped) + if (startstop == ide_stopped) { + rq = hwif->rq; + hwif->rq = NULL; goto repeat; + } } else goto plug_device; out: @@ -572,18 +580,24 @@ plug_device: plug_device_2: spin_lock_irq(q->queue_lock); + if (rq) + blk_requeue_request(q, rq); if (!elv_queue_empty(q)) blk_plug_device(q); } -static void ide_plug_device(ide_drive_t *drive) +static void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq) { struct request_queue *q = drive->queue; unsigned long flags; spin_lock_irqsave(q->queue_lock, flags); + + if (rq) + blk_requeue_request(q, rq); if (!elv_queue_empty(q)) blk_plug_device(q); + spin_unlock_irqrestore(q->queue_lock, flags); } @@ -632,6 +646,7 @@ void ide_timer_expiry (unsigned long data) unsigned long flags; int wait = -1; int plug_device = 0; + struct request *uninitialized_var(rq_in_flight); spin_lock_irqsave(&hwif->lock, flags); @@ -693,6 +708,8 @@ void ide_timer_expiry (unsigned long data) spin_lock_irq(&hwif->lock); enable_irq(hwif->irq); if (startstop == ide_stopped) { + rq_in_flight = hwif->rq; + hwif->rq = NULL; ide_unlock_port(hwif); plug_device = 1; } @@ -701,7 +718,7 @@ void ide_timer_expiry (unsigned long data) if (plug_device) { ide_unlock_host(hwif->host); - ide_plug_device(drive); + ide_requeue_and_plug(drive, rq_in_flight); } } @@ -787,6 +804,7 @@ irqreturn_t ide_intr (int irq, void *dev_id) ide_startstop_t startstop; irqreturn_t irq_ret = IRQ_NONE; int plug_device = 0; + struct request *uninitialized_var(rq_in_flight); if (host->host_flags & IDE_HFLAG_SERIALIZE) { if (hwif != host->cur_port) @@ -866,6 +884,8 @@ irqreturn_t ide_intr (int irq, void *dev_id) */ if (startstop == ide_stopped) { BUG_ON(hwif->handler); + rq_in_flight = hwif->rq; + hwif->rq = NULL; ide_unlock_port(hwif); plug_device = 1; } @@ -875,7 +895,7 @@ out: out_early: if (plug_device) { ide_unlock_host(hwif->host); - ide_plug_device(drive); + ide_requeue_and_plug(drive, rq_in_flight); } return irq_ret; -- cgit v1.2.2 From 9934c8c04561413609d2bc38c6b9f268cba774a4 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 8 May 2009 11:54:16 +0900 Subject: block: implement and enforce request peek/start/fetch Till now block layer allowed two separate modes of request execution. A request is always acquired from the request queue via elv_next_request(). After that, drivers are free to either dequeue it or process it without dequeueing. Dequeue allows elv_next_request() to return the next request so that multiple requests can be in flight. Executing requests without dequeueing has its merits mostly in allowing drivers for simpler devices which can't do sg to deal with segments only without considering request boundary. However, the benefit this brings is dubious and declining while the cost of the API ambiguity is increasing. Segment based drivers are usually for very old or limited devices and as converting to dequeueing model isn't difficult, it doesn't justify the API overhead it puts on block layer and its more modern users. Previous patches converted all block low level drivers to dequeueing model. This patch completes the API transition by... * renaming elv_next_request() to blk_peek_request() * renaming blkdev_dequeue_request() to blk_start_request() * adding blk_fetch_request() which is combination of peek and start * disallowing completion of queued (not started) requests * applying new API to all LLDs Renamings are for consistency and to break out of tree code so that it's apparent that out of tree drivers need updating. [ Impact: block request issue API cleanup, no functional change ] Signed-off-by: Tejun Heo Cc: Rusty Russell Cc: James Bottomley Cc: Mike Miller Cc: unsik Kim Cc: Paul Clements Cc: Tim Waugh Cc: Geert Uytterhoeven Cc: David S. Miller Cc: Laurent Vivier Cc: Jeff Garzik Cc: Jeremy Fitzhardinge Cc: Grant Likely Cc: Adrian McMenamin Cc: Stephen Rothwell Cc: Bartlomiej Zolnierkiewicz Cc: Borislav Petkov Cc: Sergei Shtylyov Cc: Alex Dubov Cc: Pierre Ossman Cc: David Woodhouse Cc: Markus Lidel Cc: Stefan Weinhuber Cc: Martin Schwidefsky Cc: Pete Zaitcev Cc: FUJITA Tomonori Signed-off-by: Jens Axboe --- drivers/ide/ide-io.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'drivers/ide/ide-io.c') diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c index abda7337b3f4..e4e3a0e3201e 100644 --- a/drivers/ide/ide-io.c +++ b/drivers/ide/ide-io.c @@ -519,11 +519,8 @@ repeat: * we know that the queue isn't empty, but this can happen * if the q->prep_rq_fn() decides to kill a request */ - if (!rq) { - rq = elv_next_request(drive->queue); - if (rq) - blkdev_dequeue_request(rq); - } + if (!rq) + rq = blk_fetch_request(drive->queue); spin_unlock_irq(q->queue_lock); spin_lock_irq(&hwif->lock); @@ -536,7 +533,7 @@ repeat: /* * Sanity: don't accept a request that isn't a PM request * if we are currently power managed. This is very important as - * blk_stop_queue() doesn't prevent the elv_next_request() + * blk_stop_queue() doesn't prevent the blk_fetch_request() * above to return us whatever is in the queue. Since we call * ide_do_request() ourselves, we end up taking requests while * the queue is blocked... -- cgit v1.2.2