ide-taskfile: don't abuse rq->buffer

Impact: rq->buffer usage cleanup

ide_raw_taskfile() directly uses rq->buffer to carry pointer to the
data buffer.  This complicates both block interface and ide backend
request handling.  Use blk_rq_map_kern() instead and drop special
handling for REQ_TYPE_ATA_TASKFILE from ide_map_sg().

Note that REQ_RW setting is moved upwards as blk_rq_map_kern() uses it
to initialize bio rw flag.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>

2 files changed, 12 insertions, 11 deletions

diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 35dc38d3b2c5..9b9e8b1aae5e 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -248,10 +248,7 @@ void ide_map_sg(ide_drive_t *drive, struct ide_cmd *cmd)
         struct scatterlist *sg = hwif->sg_table;
         struct request *rq = cmd->rq;
 
-        if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
-                sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE);
-                cmd->sg_nents = 1;
-        } else if (!rq->bio) {
+        if (!rq->bio) {
                 sg_init_one(sg, rq->data, rq->data_len);
                 cmd->sg_nents = 1;
         } else
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index 4aa6223c11be..f400eb4d4aff 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -424,7 +424,9 @@ int ide_raw_taskfile(ide_drive_t *drive, struct ide_cmd *cmd, u8 *buf,
 
         rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
         rq->cmd_type = REQ_TYPE_ATA_TASKFILE;
-        rq->buffer = buf;
+
+        if (cmd->tf_flags & IDE_TFLAG_WRITE)
+                rq->cmd_flags |= REQ_RW;
 
         /*
          * (ks) We transfer currently only whole sectors.
@@ -432,18 +434,20 @@ int ide_raw_taskfile(ide_drive_t *drive, struct ide_cmd *cmd, u8 *buf,
          * if we would find a solution to transfer any size.
          * To support special commands like READ LONG.
          */
-        rq->hard_nr_sectors = rq->nr_sectors = nsect;
-        rq->hard_cur_sectors = rq->current_nr_sectors = nsect;
-
-        if (cmd->tf_flags & IDE_TFLAG_WRITE)
-                rq->cmd_flags |= REQ_RW;
+        if (nsect) {
+                error = blk_rq_map_kern(drive->queue, rq, buf,
+                                        nsect * SECTOR_SIZE, __GFP_WAIT);
+                if (error)
+                        goto put_req;
+        }
 
         rq->special = cmd;
         cmd->rq = rq;
 
         error = blk_execute_rq(drive->queue, NULL, rq, 0);
-        blk_put_request(rq);
 
+put_req:
+        blk_put_request(rq);
         return error;
 }