block: move dma_pad handling from blk_rq_map_sg into the callers

There are only two callers of blk_rq_map_sg/__blk_rq_map_sg that set
the dma_pad value in the queue.  Move the handling into those callers
instead of burdening the common code, and move the ->extra_len field
from struct request to struct scsi_cmnd.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-core.c b/block/blk-core.c
index 7e4a1da..311596d 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1638,7 +1638,6 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
        }
        rq->nr_phys_segments = rq_src->nr_phys_segments;
        rq->ioprio = rq_src->ioprio;
-       rq->extra_len = rq_src->extra_len;
 
        return 0;
 

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 25f5a5e..c49eb3b 100644 (file)
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -531,14 +531,6 @@ int __blk_rq_map_sg(struct request_queue *q, struct request *rq,
        else if (rq->bio)
                nsegs = __blk_bios_map_sg(q, rq->bio, sglist, last_sg);
 
-       if (blk_rq_bytes(rq) && (blk_rq_bytes(rq) & q->dma_pad_mask)) {
-               unsigned int pad_len =
-                       (q->dma_pad_mask & ~blk_rq_bytes(rq)) + 1;
-
-               (*last_sg)->length += pad_len;
-               rq->extra_len += pad_len;
-       }
-
        if (*last_sg)
                sg_mark_end(*last_sg);
 

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 2c105cb..71d0894 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -318,7 +318,6 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
        rq->nr_integrity_segments = 0;
 #endif
        /* tag was already set */
-       rq->extra_len = 0;
        WRITE_ONCE(rq->deadline, 0);
 
        rq->timeout = 0;

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index feb13b8..435781a 100644 (file)
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -649,7 +649,7 @@ static void ata_qc_set_pc_nbytes(struct ata_queued_cmd *qc)
 {
        struct scsi_cmnd *scmd = qc->scsicmd;
 
-       qc->extrabytes = scmd->request->extra_len;
+       qc->extrabytes = scmd->extra_len;
        qc->nbytes = scsi_bufflen(scmd) + qc->extrabytes;
 }
 

diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index b137f27..c31f1d2 100644 (file)
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -233,10 +233,13 @@ static ide_startstop_t do_special(ide_drive_t *drive)
 void ide_map_sg(ide_drive_t *drive, struct ide_cmd *cmd)
 {
        ide_hwif_t *hwif = drive->hwif;
-       struct scatterlist *sg = hwif->sg_table;
+       struct scatterlist *sg = hwif->sg_table, *last_sg = NULL;
        struct request *rq = cmd->rq;
 
-       cmd->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
+       cmd->sg_nents = __blk_rq_map_sg(drive->queue, rq, sg, &last_sg);
+       if (blk_rq_bytes(rq) && (blk_rq_bytes(rq) & rq->q->dma_pad_mask))
+               last_sg->length +=
+                       (rq->q->dma_pad_mask & ~blk_rq_bytes(rq)) + 1;
 }
 EXPORT_SYMBOL_GPL(ide_map_sg);
 

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 88cac92..0a73230 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1030,13 +1030,21 @@ blk_status_t scsi_init_io(struct scsi_cmnd *cmd)
         */
        count = __blk_rq_map_sg(rq->q, rq, cmd->sdb.table.sgl, &last_sg);
 
+       if (blk_rq_bytes(rq) & rq->q->dma_pad_mask) {
+               unsigned int pad_len =
+                       (rq->q->dma_pad_mask & ~blk_rq_bytes(rq)) + 1;
+
+               last_sg->length += pad_len;
+               cmd->extra_len += pad_len;
+       }
+
        if (need_drain) {
                sg_unmark_end(last_sg);
                last_sg = sg_next(last_sg);
                sg_set_buf(last_sg, sdev->dma_drain_buf, sdev->dma_drain_len);
                sg_mark_end(last_sg);
 
-               rq->extra_len += sdev->dma_drain_len;
+               cmd->extra_len += sdev->dma_drain_len;
                count++;
        }
 

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 8e4726b..f00bd40 100644 (file)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -224,8 +224,6 @@ struct request {
        unsigned short write_hint;
        unsigned short ioprio;
 
-       unsigned int extra_len; /* length of alignment and padding */
-
        enum mq_rq_state state;
        refcount_t ref;
 

diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 80ac89e..f93c0b8 100644 (file)
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -142,6 +142,7 @@ struct scsi_cmnd {
        unsigned long state;    /* Command completion state */
 
        unsigned char tag;      /* SCSI-II queued command tag */
+       unsigned int extra_len; /* length of alignment and padding */
 };
 
 /*