From: Mike Christie <michaelc@xxxxxxxxxxx>
We have been seeing the flush requests time out, so this patch
adds a new setting, /sys/block/$name/queue/flush_timeout, that
controls the time out for the flush request.
The patch was made and tested over the linux-2.6-block tree's
for-2.6.36 branch.
Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx>
---
block/blk-barrier.c | 3 +++
block/blk-sysfs.c | 30 ++++++++++++++++++++++++++++++
drivers/scsi/sd.c | 4 ++--
include/linux/blkdev.h | 2 ++
4 files changed, 37 insertions(+), 2 deletions(-)
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index 557f693..61fe561 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -36,6 +36,7 @@ int blk_queue_ordered(struct request_queue *q, unsigned ordered)
q->ordered = ordered;
q->next_ordered = ordered;
+ q->flush_timeout = BLKDEV_DEF_FLUSH_TIMEOUT;
return 0;
}
@@ -137,6 +138,8 @@ static void queue_flush(struct request_queue *q, unsigned which)
rq->cmd_flags = REQ_HARDBARRIER | REQ_FLUSH;
rq->rq_disk = q->bar_rq.rq_disk;
rq->end_io = end_io;
+ if (q->rq_timed_out_fn)
+ rq->timeout = q->flush_timeout;
elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
}
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 001ab18..94604b5 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -260,6 +260,35 @@ queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
return ret;
}
+static ssize_t queue_flush_timeout_show(struct request_queue *q, char *page)
+{
+ if (!q->rq_timed_out_fn)
+ return -EINVAL;
+
+ return queue_var_show(q->flush_timeout / HZ, page);
+}
+
+static ssize_t
+queue_flush_timeout_store(struct request_queue *q, const char *page,
+ size_t count)
+{
+ unsigned long timeout;
+ int ret;
+
+ if (!q->rq_timed_out_fn)
+ return -EINVAL;
+
+ ret = queue_var_store(&timeout, page, count);
+ q->flush_timeout = timeout * HZ;
+ return ret;
+}
+
+static struct queue_sysfs_entry queue_flush_timeout_entry = {
+ .attr = {.name = "flush_timeout", .mode = S_IRUGO | S_IWUSR },
+ .show = queue_flush_timeout_show,
+ .store = queue_flush_timeout_store,
+};
+
static struct queue_sysfs_entry queue_requests_entry = {
.attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
.show = queue_requests_show,
@@ -370,6 +399,7 @@ static struct queue_sysfs_entry queue_random_entry = {
};
static struct attribute *default_attrs[] = {
+ &queue_flush_timeout_entry.attr,
&queue_requests_entry.attr,
&queue_ra_entry.attr,
&queue_max_hw_sectors_entry.attr,
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index fc5d69a..77af48d 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -480,7 +480,6 @@ static int scsi_setup_flush_cmnd(struct scsi_device *sdp, struct request *rq)
{
/* for now, we use REQ_TYPE_BLOCK_PC. */
rq->cmd_type = REQ_TYPE_BLOCK_PC;
- rq->timeout = SD_TIMEOUT;
rq->retries = SD_MAX_RETRIES;
rq->cmd[0] = SYNCHRONIZE_CACHE;
rq->cmd_len = 10;
@@ -1067,7 +1066,8 @@ static int sd_sync_cache(struct scsi_disk *sdkp)
* flush everything.
*/
res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
- SD_TIMEOUT, SD_MAX_RETRIES, NULL);
+ sdp->request_queue->flush_timeout,
+ SD_MAX_RETRIES, NULL);
if (res == 0)
break;
}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index a8b05fc..477101a 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -361,6 +361,7 @@ struct request_queue
int orderr, ordcolor;
struct request pre_flush_rq, bar_rq, post_flush_rq;
struct request *orig_bar_rq;
+ unsigned int flush_timeout;
struct mutex sysfs_lock;
@@ -922,6 +923,7 @@ enum{
};
#define BLKDEV_IFL_WAIT (1 << BLKDEV_WAIT)
#define BLKDEV_IFL_BARRIER (1 << BLKDEV_BARRIER)
+#define BLKDEV_DEF_FLUSH_TIMEOUT 30 * HZ
extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *,
unsigned long);
extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
--
1.6.6.1
--
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