This patch changes rq->cmd from the static array to a pointer to
support large commands.
We rarely handle large commands. So for optimization, a struct request
still has a static array for a command. rq_init sets rq->cmd pointer
to the static array.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Cc: Jens Axboe <jens.axboe@xxxxxxxxxx>
---
block/blk-core.c | 1 +
drivers/ide/ide-io.c | 1 +
include/linux/blkdev.h | 12 ++++++++++--
3 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 6669238..6f0968f 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -132,6 +132,7 @@ void rq_init(struct request_queue *q, struct request *rq)
rq->errors = 0;
rq->ref_count = 1;
rq->cmd_len = 0;
+ rq->cmd = rq->__cmd;
memset(rq->cmd, 0, BLK_MAX_CDB);
rq->data_len = 0;
rq->extra_len = 0;
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 7153796..bac5ea1 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -1595,6 +1595,7 @@ void ide_init_drive_cmd (struct request *rq)
{
memset(rq, 0, sizeof(*rq));
rq->ref_count = 1;
+ rq->cmd = rq->__cmd;
}
EXPORT_SYMBOL(ide_init_drive_cmd);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index b3a58ad..5710ae4 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -215,8 +215,9 @@ struct request {
/*
* when request is used as a packet command carrier
*/
- unsigned int cmd_len;
- unsigned char cmd[BLK_MAX_CDB];
+ unsigned short cmd_len;
+ unsigned char __cmd[BLK_MAX_CDB];
+ unsigned char *cmd;
unsigned int data_len;
unsigned int extra_len; /* length of alignment and padding */
@@ -812,6 +813,13 @@ static inline void put_dev_sector(Sector p)
page_cache_release(p.v);
}
+static inline void rq_set_cmd(struct request *rq, unsigned char *cmd,
+ unsigned short cmd_len)
+{
+ rq->cmd = cmd;
+ rq->cmd_len = cmd_len;
+}
+
struct work_struct;
int kblockd_schedule_work(struct work_struct *work);
void kblockd_flush_work(struct work_struct *work);
--
1.5.4.2
--
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