block: restore the meaning of rq->data_len to the true data length
The meaning of rq->data_len was changed to the length of an allocated
buffer from the true data length. It breaks SG_IO friends and
bsg. This patch restores the meaning of rq->data_len to the true data
length and adds rq->extra_len to store an extended length (due to
drain buffer and padding).
This patch also removes the code to update bio in blk_rq_map_user
introduced by the commit 40b01b9bbdf51ae543a04744283bf2d56c4a6afa.
The commit adjusts bio according to memory alignment
(queue_dma_alignment). However, memory alignment is NOT padding
alignment. This adjustment also breaks SG_IO friends and bsg. Padding
alignment needs to be fixed in a proper way (by a separate patch).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
diff --git a/block/blk-core.c b/block/blk-core.c
index 2d7e3a2..a248cf1 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -127,7 +127,6 @@
rq->nr_hw_segments = 0;
rq->ioprio = 0;
rq->special = NULL;
- rq->raw_data_len = 0;
rq->buffer = NULL;
rq->tag = -1;
rq->errors = 0;
@@ -135,6 +134,7 @@
rq->cmd_len = 0;
memset(rq->cmd, 0, sizeof(rq->cmd));
rq->data_len = 0;
+ rq->extra_len = 0;
rq->sense_len = 0;
rq->data = NULL;
rq->sense = NULL;
@@ -2018,7 +2018,6 @@
rq->hard_cur_sectors = rq->current_nr_sectors;
rq->hard_nr_sectors = rq->nr_sectors = bio_sectors(bio);
rq->buffer = bio_data(bio);
- rq->raw_data_len = bio->bi_size;
rq->data_len = bio->bi_size;
rq->bio = rq->biotail = bio;
diff --git a/block/blk-map.c b/block/blk-map.c
index 09f7fd0..f559832 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -19,7 +19,6 @@
rq->biotail->bi_next = bio;
rq->biotail = bio;
- rq->raw_data_len += bio->bi_size;
rq->data_len += bio->bi_size;
}
return 0;
@@ -151,11 +150,8 @@
*/
if (len & queue_dma_alignment(q)) {
unsigned int pad_len = (queue_dma_alignment(q) & ~len) + 1;
- struct bio *bio = rq->biotail;
- bio->bi_io_vec[bio->bi_vcnt - 1].bv_len += pad_len;
- bio->bi_size += pad_len;
- rq->data_len += pad_len;
+ rq->extra_len += pad_len;
}
rq->buffer = rq->data = NULL;
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 7506c4f..0f58616 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -231,7 +231,7 @@
((unsigned long)q->dma_drain_buffer) &
(PAGE_SIZE - 1));
nsegs++;
- rq->data_len += q->dma_drain_size;
+ rq->extra_len += q->dma_drain_size;
}
if (sg)
diff --git a/block/bsg.c b/block/bsg.c
index 7f3c095..8917c51 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -437,14 +437,14 @@
}
if (rq->next_rq) {
- hdr->dout_resid = rq->raw_data_len;
- hdr->din_resid = rq->next_rq->raw_data_len;
+ hdr->dout_resid = rq->data_len;
+ hdr->din_resid = rq->next_rq->data_len;
blk_rq_unmap_user(bidi_bio);
blk_put_request(rq->next_rq);
} else if (rq_data_dir(rq) == READ)
- hdr->din_resid = rq->raw_data_len;
+ hdr->din_resid = rq->data_len;
else
- hdr->dout_resid = rq->raw_data_len;
+ hdr->dout_resid = rq->data_len;
/*
* If the request generated a negative error number, return it
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index e993cac..a2c3a93 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -266,7 +266,7 @@
hdr->info = 0;
if (hdr->masked_status || hdr->host_status || hdr->driver_status)
hdr->info |= SG_INFO_CHECK;
- hdr->resid = rq->raw_data_len;
+ hdr->resid = rq->data_len;
hdr->sb_len_wr = 0;
if (rq->sense_len && hdr->sbp) {
@@ -528,8 +528,8 @@
rq = blk_get_request(q, WRITE, __GFP_WAIT);
rq->cmd_type = REQ_TYPE_BLOCK_PC;
rq->data = NULL;
- rq->raw_data_len = 0;
rq->data_len = 0;
+ rq->extra_len = 0;
rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
memset(rq->cmd, 0, sizeof(rq->cmd));
rq->cmd[0] = cmd;
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 7b1f1ee..fe47922 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -2538,7 +2538,7 @@
}
qc->tf.command = ATA_CMD_PACKET;
- qc->nbytes = scsi_bufflen(scmd);
+ qc->nbytes = scsi_bufflen(scmd) + scmd->request->extra_len;
/* check whether ATAPI DMA is safe */
if (!using_pio && ata_check_atapi_dma(qc))
@@ -2549,7 +2549,7 @@
* want to set it properly, and for DMA where it is
* effectively meaningless.
*/
- nbytes = min(scmd->request->raw_data_len, (unsigned int)63 * 1024);
+ nbytes = min(scmd->request->data_len, (unsigned int)63 * 1024);
/* Most ATAPI devices which honor transfer chunk size don't
* behave according to the spec when odd chunk size which
@@ -2875,7 +2875,7 @@
* TODO: find out if we need to do more here to
* cover scatter/gather case.
*/
- qc->nbytes = scsi_bufflen(scmd);
+ qc->nbytes = scsi_bufflen(scmd) + scmd->request->extra_len;
/* request result TF and be quiet about device error */
qc->flags |= ATA_QCFLAG_RESULT_TF | ATA_QCFLAG_QUIET;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6fe67d1..b72526c 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -216,8 +216,8 @@
unsigned int cmd_len;
unsigned char cmd[BLK_MAX_CDB];
- unsigned int raw_data_len;
unsigned int data_len;
+ unsigned int extra_len; /* length of alignment and padding */
unsigned int sense_len;
void *data;
void *sense;