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 9c2549260427..067f28b80072 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 f9f6e793575c..855bf95963e7 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 44a55d1bf530..d123ca84e732 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 490bd13a634c..0de32cd4e8a7 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