block: unify request timeout handling

Right now SCSI and others do their own command timeout handling.
Move those bits to the block layer.

Instead of having a timer per command, we try to be a bit more clever
and simply have one per-queue. This avoids the overhead of having to
tear down and setup a timer for each command, so it will result in a lot
less timer fiddling.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

4 files changed, 23 insertions, 12 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 9c254926042..067f28b8007 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -147,6 +147,7 @@ struct request {
 
 	unsigned int cmd_flags;
 	enum rq_cmd_type_bits cmd_type;
+	unsigned long atomic_flags;
 
 	/* Maintain bio traversal state for part by part I/O submission.
 	 * hard_* are block layer internals, no driver should touch them!
@@ -214,6 +215,8 @@ struct request {
 	void *data;
 	void *sense;
 
+	unsigned long deadline;
+	struct list_head timeout_list;
 	unsigned int timeout;
 	int retries;
 
@@ -266,6 +269,14 @@ typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
 typedef void (softirq_done_fn)(struct request *);
 typedef int (dma_drain_needed_fn)(struct request *);
 
+enum blk_eh_timer_return {
+	BLK_EH_NOT_HANDLED,
+	BLK_EH_HANDLED,
+	BLK_EH_RESET_TIMER,
+};
+
+typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
+
 enum blk_queue_state {
 	Queue_down,
 	Queue_up,
@@ -311,6 +322,7 @@ struct request_queue
 	merge_bvec_fn		*merge_bvec_fn;
 	prepare_flush_fn	*prepare_flush_fn;
 	softirq_done_fn		*softirq_done_fn;
+	rq_timed_out_fn		*rq_timed_out_fn;
 	dma_drain_needed_fn	*dma_drain_needed;
 
 	/*
@@ -386,6 +398,10 @@ struct request_queue
 	unsigned int		nr_sorted;
 	unsigned int		in_flight;
 
+	unsigned int		rq_timeout;
+	struct timer_list	timeout;
+	struct list_head	timeout_list;
+
 	/*
 	 * sg stuff
 	 */
@@ -770,6 +786,8 @@ extern int blk_end_request_callback(struct request *rq, int error,
 				unsigned int nr_bytes,
 				int (drv_callback)(struct request *));
 extern void blk_complete_request(struct request *);
+extern void __blk_complete_request(struct request *);
+extern void blk_abort_request(struct request *);
 
 /*
  * blk_end_request() takes bytes instead of sectors as a complete size.
@@ -811,6 +829,8 @@ extern void blk_queue_dma_alignment(struct request_queue *, int);
 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
 extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *);
+extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
+extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
 extern int blk_do_ordered(struct request_queue *, struct request **);
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index f9f6e793575..855bf95963e 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -75,7 +75,6 @@ struct scsi_cmnd {
 
 	int retries;
 	int allowed;
-	int timeout_per_command;
 
 	unsigned char prot_op;
 	unsigned char prot_type;
@@ -86,7 +85,6 @@ struct scsi_cmnd {
 	/* These elements define the operation we are about to perform */
 	unsigned char *cmnd;
 
-	struct timer_list eh_timeout;	/* Used to time out the command. */
 
 	/* These elements define the operation we ultimately want to perform */
 	struct scsi_data_buffer sdb;
@@ -139,7 +137,6 @@ extern void scsi_put_command(struct scsi_cmnd *);
 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
 			       struct device *);
 extern void scsi_finish_command(struct scsi_cmnd *cmd);
-extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);
 
 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 				 size_t *offset, size_t *len);
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 44a55d1bf53..d123ca84e73 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -43,13 +43,6 @@ struct blk_queue_tags;
 #define DISABLE_CLUSTERING 0
 #define ENABLE_CLUSTERING 1
 
-enum scsi_eh_timer_return {
-	EH_NOT_HANDLED,
-	EH_HANDLED,
-	EH_RESET_TIMER,
-};
-
-
 struct scsi_host_template {
 	struct module *module;
 	const char *name;
@@ -347,7 +340,7 @@ struct scsi_host_template {
 	 *
 	 * Status: OPTIONAL
 	 */
-	enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
+	enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
 
 	/*
 	 * Name of proc directory
diff --git a/include/scsi/scsi_transport.h b/include/scsi/scsi_transport.h
index 490bd13a634..0de32cd4e8a 100644
--- a/include/scsi/scsi_transport.h
+++ b/include/scsi/scsi_transport.h
@@ -21,6 +21,7 @@
 #define SCSI_TRANSPORT_H
 
 #include <linux/transport_class.h>
+#include <linux/blkdev.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_device.h>
 
@@ -64,7 +65,7 @@ struct scsi_transport_template {
 	 *			begin counting again
 	 * EH_NOT_HANDLED	Begin normal error recovery
 	 */
-	enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
+	enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
 
 	/*
 	 * Used as callback for the completion of i_t_nexus request