q->request_fn(q);
}
- EXPORT_SYMBOL(__generic_unplug_device);
/**
* generic_unplug_device - fire a request queue
static void blk_invoke_request_fn(struct request_queue *q)
{
+ if (unlikely(blk_queue_stopped(q)))
+ return;
+
/*
* one level of recursion is ok and is much faster than kicking
* the unplug handling
EXPORT_SYMBOL(blk_sync_queue);
/**
- * blk_run_queue - run a single device queue
+ * __blk_run_queue - run a single device queue
* @q: The queue to run
+ *
+ * Description:
+ * See @blk_run_queue. This variant must be called with the queue lock
+ * held and interrupts disabled.
+ *
*/
void __blk_run_queue(struct request_queue *q)
{
/**
* blk_run_queue - run a single device queue
* @q: The queue to run
+ *
+ * Description:
+ * Invoke request handling on this queue, if it has pending work to do.
+ * May be used to restart queueing when a request has completed. Also
+ * See @blk_start_queueing.
+ *
*/
void blk_run_queue(struct request_queue *q)
{
init_timer(&q->unplug_timer);
setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
INIT_LIST_HEAD(&q->timeout_list);
+ INIT_WORK(&q->unplug_work, blk_unplug_work);
kobject_init(&q->kobj, &blk_queue_ktype);
*
* This is basically a helper to remove the need to know whether a queue
* is plugged or not if someone just wants to initiate dispatch of requests
- * for this queue.
+ * for this queue. Should be used to start queueing on a device outside
+ * of ->request_fn() context. Also see @blk_run_queue.
*
* The queue lock must be held with interrupts disabled.
*/
}
/**
- * part_round_stats() - Round off the performance stats on a struct
- * disk_stats.
+ * part_round_stats() - Round off the performance stats on a struct disk_stats.
+ * @cpu: cpu number for stats access
+ * @part: target partition
*
* The average IO queue length and utilisation statistics are maintained
* by observing the current state of the queue length and the amount of
/*
* inherit FAILFAST from bio (for read-ahead, and explicit FAILFAST)
*/
- if (bio_rw_ahead(bio) || bio_failfast(bio))
- req->cmd_flags |= REQ_FAILFAST;
+ if (bio_rw_ahead(bio))
+ req->cmd_flags |= (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
+ REQ_FAILFAST_DRIVER);
+ if (bio_failfast_dev(bio))
+ req->cmd_flags |= REQ_FAILFAST_DEV;
+ if (bio_failfast_transport(bio))
+ req->cmd_flags |= REQ_FAILFAST_TRANSPORT;
+ if (bio_failfast_driver(bio))
+ req->cmd_flags |= REQ_FAILFAST_DRIVER;
/*
* REQ_BARRIER implies no merging, but lets make it explicit
unsigned int bi_size; /* residual I/O count */
+ /*
+ * To keep track of the max segment size, we account for the
+ * sizes of the first and last mergeable segments in this bio.
+ */
+ unsigned int bi_seg_front_size;
+ unsigned int bi_seg_back_size;
+
unsigned int bi_max_vecs; /* max bvl_vecs we can hold */
unsigned int bi_comp_cpu; /* completion CPU */
* bit 2 -- barrier
* Insert a serialization point in the IO queue, forcing previously
* submitted IO to be completed before this oen is issued.
- * bit 3 -- fail fast, don't want low level driver retries
- * bit 4 -- synchronous I/O hint: the block layer will unplug immediately
+ * bit 3 -- synchronous I/O hint: the block layer will unplug immediately
* Note that this does NOT indicate that the IO itself is sync, just
* that the block layer will not postpone issue of this IO by plugging.
- * bit 5 -- metadata request
+ * bit 4 -- metadata request
* Used for tracing to differentiate metadata and data IO. May also
* get some preferential treatment in the IO scheduler
- * bit 6 -- discard sectors
+ * bit 5 -- discard sectors
* Informs the lower level device that this range of sectors is no longer
* used by the file system and may thus be freed by the device. Used
* for flash based storage.
+ * bit 6 -- fail fast device errors
+ * bit 7 -- fail fast transport errors
+ * bit 8 -- fail fast driver errors
+ * Don't want driver retries for any fast fail whatever the reason.
*/
#define BIO_RW 0 /* Must match RW in req flags (blkdev.h) */
#define BIO_RW_AHEAD 1 /* Must match FAILFAST in req flags */
#define BIO_RW_BARRIER 2
-#define BIO_RW_FAILFAST 3
-#define BIO_RW_SYNC 4
-#define BIO_RW_META 5
-#define BIO_RW_DISCARD 6
+#define BIO_RW_SYNC 3
+#define BIO_RW_META 4
+#define BIO_RW_DISCARD 5
+#define BIO_RW_FAILFAST_DEV 6
+#define BIO_RW_FAILFAST_TRANSPORT 7
+#define BIO_RW_FAILFAST_DRIVER 8
/*
* upper 16 bits of bi_rw define the io priority of this bio
#define bio_sectors(bio) ((bio)->bi_size >> 9)
#define bio_barrier(bio) ((bio)->bi_rw & (1 << BIO_RW_BARRIER))
#define bio_sync(bio) ((bio)->bi_rw & (1 << BIO_RW_SYNC))
-#define bio_failfast(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST))
+#define bio_failfast_dev(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_DEV))
+#define bio_failfast_transport(bio) \
+ ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_TRANSPORT))
+#define bio_failfast_driver(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_DRIVER))
#define bio_rw_ahead(bio) ((bio)->bi_rw & (1 << BIO_RW_AHEAD))
#define bio_rw_meta(bio) ((bio)->bi_rw & (1 << BIO_RW_META))
#define bio_discard(bio) ((bio)->bi_rw & (1 << BIO_RW_DISCARD))
*/
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 */
};
#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)
#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)))
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 *);
projects / linux-2.6-omap-h63xx.git / commitdiff