ide-scsi: sg chaining support
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/scsi/ide-scsi.c b/drivers/scsi/ide-scsi.c
index d81bb076..d297f64 100644
--- a/drivers/scsi/ide-scsi.c
+++ b/drivers/scsi/ide-scsi.c
@@ -70,6 +70,7 @@
u8 *buffer; /* Data buffer */
u8 *current_position; /* Pointer into the above buffer */
struct scatterlist *sg; /* Scatter gather table */
+ struct scatterlist *last_sg; /* Last sg element */
int b_count; /* Bytes transferred from current entry */
struct scsi_cmnd *scsi_cmd; /* SCSI command */
void (*done)(struct scsi_cmnd *); /* Scsi completion routine */
@@ -173,12 +174,6 @@
char *buf;
while (bcount) {
- if (pc->sg - scsi_sglist(pc->scsi_cmd) >
- scsi_sg_count(pc->scsi_cmd)) {
- printk (KERN_ERR "ide-scsi: scatter gather table too small, discarding data\n");
- idescsi_discard_data (drive, bcount);
- return;
- }
count = min(pc->sg->length - pc->b_count, bcount);
if (PageHighMem(pc->sg->page)) {
unsigned long flags;
@@ -197,10 +192,17 @@
}
bcount -= count; pc->b_count += count;
if (pc->b_count == pc->sg->length) {
- pc->sg++;
+ if (pc->sg == pc->last_sg)
+ break;
+ pc->sg = sg_next(pc->sg);
pc->b_count = 0;
}
}
+
+ if (bcount) {
+ printk (KERN_ERR "ide-scsi: scatter gather table too small, discarding data\n");
+ idescsi_discard_data (drive, bcount);
+ }
}
static void idescsi_output_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsigned int bcount)
@@ -209,12 +211,6 @@
char *buf;
while (bcount) {
- if (pc->sg - scsi_sglist(pc->scsi_cmd) >
- scsi_sg_count(pc->scsi_cmd)) {
- printk (KERN_ERR "ide-scsi: scatter gather table too small, padding with zeros\n");
- idescsi_output_zeros (drive, bcount);
- return;
- }
count = min(pc->sg->length - pc->b_count, bcount);
if (PageHighMem(pc->sg->page)) {
unsigned long flags;
@@ -233,10 +229,17 @@
}
bcount -= count; pc->b_count += count;
if (pc->b_count == pc->sg->length) {
- pc->sg++;
+ if (pc->sg == pc->last_sg)
+ break;
+ pc->sg = sg_next(pc->sg);
pc->b_count = 0;
}
}
+
+ if (bcount) {
+ printk (KERN_ERR "ide-scsi: scatter gather table too small, padding with zeros\n");
+ idescsi_output_zeros (drive, bcount);
+ }
}
static void hexdump(u8 *x, int len)
@@ -804,6 +807,7 @@
memcpy (pc->c, cmd->cmnd, cmd->cmd_len);
pc->buffer = NULL;
pc->sg = scsi_sglist(cmd);
+ pc->last_sg = sg_last(pc->sg, cmd->use_sg);
pc->b_count = 0;
pc->request_transfer = pc->buffer_size = scsi_bufflen(cmd);
pc->scsi_cmd = cmd;