From 6000a368cd8e6da1caf101411bdb494cd6fb8b09 Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Tue, 19 Aug 2008 18:45:30 -0500 Subject: [SCSI] block: separate failfast into multiple bits. Multipath is best at handling transport errors. If it gets a device error then there is not much the multipath layer can do. It will just access the same device but from a different path. This patch breaks up failfast into device, transport and driver errors. The multipath layers (md and dm mutlipath) only ask the lower levels to fast fail transport errors. The user of failfast, read ahead, will ask to fast fail on all errors. Note that blk_noretry_request will return true if any failfast bit is set. This allows drivers that do not support the multipath failfast bits to continue to fail on any failfast error like before. Drivers like scsi that are able to fail fast specific errors can check for the specific fail fast type. In the next patch I will convert scsi. Signed-off-by: Mike Christie Cc: Jens Axboe Signed-off-by: James Bottomley --- include/linux/blkdev.h | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index a92d9e4ea96e..f3491d225268 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -87,7 +87,9 @@ enum { */ enum rq_flag_bits { __REQ_RW, /* not set, read. set, write */ - __REQ_FAILFAST, /* no low level driver retries */ + __REQ_FAILFAST_DEV, /* no driver retries of device errors */ + __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */ + __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */ __REQ_DISCARD, /* request to discard sectors */ __REQ_SORTED, /* elevator knows about this request */ __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ @@ -111,8 +113,10 @@ enum rq_flag_bits { }; #define REQ_RW (1 << __REQ_RW) +#define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV) +#define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT) +#define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER) #define REQ_DISCARD (1 << __REQ_DISCARD) -#define REQ_FAILFAST (1 << __REQ_FAILFAST) #define REQ_SORTED (1 << __REQ_SORTED) #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) @@ -560,7 +564,12 @@ enum { #define blk_special_request(rq) ((rq)->cmd_type == REQ_TYPE_SPECIAL) #define blk_sense_request(rq) ((rq)->cmd_type == REQ_TYPE_SENSE) -#define blk_noretry_request(rq) ((rq)->cmd_flags & REQ_FAILFAST) +#define blk_failfast_dev(rq) ((rq)->cmd_flags & REQ_FAILFAST_DEV) +#define blk_failfast_transport(rq) ((rq)->cmd_flags & REQ_FAILFAST_TRANSPORT) +#define blk_failfast_driver(rq) ((rq)->cmd_flags & REQ_FAILFAST_DRIVER) +#define blk_noretry_request(rq) (blk_failfast_dev(rq) || \ + blk_failfast_transport(rq) || \ + blk_failfast_driver(rq)) #define blk_rq_started(rq) ((rq)->cmd_flags & REQ_STARTED) #define blk_account_rq(rq) (blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq))) -- cgit v1.2.3 From f73e2d13a16cc88c4faa4729967f92bfeec8a142 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 17 Oct 2008 14:03:08 +0200 Subject: block: remove __generic_unplug_device() from exports The only out-of-core user is IDE, and that should be using blk_start_queueing() instead. Signed-off-by: Jens Axboe --- block/blk-core.c | 1 - block/blk.h | 1 + drivers/ide/ide-io.c | 4 ++-- include/linux/blkdev.h | 1 - 4 files changed, 3 insertions(+), 4 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/block/blk-core.c b/block/blk-core.c index fcbd56dd41fa..81a496004976 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -257,7 +257,6 @@ void __generic_unplug_device(struct request_queue *q) q->request_fn(q); } -EXPORT_SYMBOL(__generic_unplug_device); /** * generic_unplug_device - fire a request queue diff --git a/block/blk.h b/block/blk.h index e5c579769963..d2e49af90db5 100644 --- a/block/blk.h +++ b/block/blk.h @@ -20,6 +20,7 @@ void blk_unplug_timeout(unsigned long data); void blk_rq_timed_out_timer(unsigned long data); void blk_delete_timer(struct request *); void blk_add_timer(struct request *); +void __generic_unplug_device(struct request_queue *); /* * Internal atomic flags for request handling diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c index 77c6eaeacefa..7162d67562af 100644 --- a/drivers/ide/ide-io.c +++ b/drivers/ide/ide-io.c @@ -1493,8 +1493,8 @@ void ide_do_drive_cmd(ide_drive_t *drive, struct request *rq) spin_lock_irqsave(&ide_lock, flags); hwgroup->rq = NULL; - __elv_add_request(drive->queue, rq, ELEVATOR_INSERT_FRONT, 1); - __generic_unplug_device(drive->queue); + __elv_add_request(drive->queue, rq, ELEVATOR_INSERT_FRONT, 0); + blk_start_queueing(drive->queue); spin_unlock_irqrestore(&ide_lock, flags); } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index a92d9e4ea96e..8eed8b15f992 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -856,7 +856,6 @@ extern void blk_ordered_complete_seq(struct request_queue *, unsigned, int); extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); extern void blk_dump_rq_flags(struct request *, char *); extern void generic_unplug_device(struct request_queue *); -extern void __generic_unplug_device(struct request_queue *); extern long nr_blockdev_pages(void); int blk_get_queue(struct request_queue *); -- cgit v1.2.3