Mostly revert r260267 and hopefully really fix the original problem.

The latest draft of SBC-3 tells: "A MAXIMUM UNMAP LBA COUNT field set to
a non-zero value indicates the maximum number of LBAs that may be unmapped
by an UNMAP command."  To me it does not sound like that limit is set per
single descriptor, but rather per all command.  And I have at least one
device that behaves exactly that way.  This patch fixes the problem there.

MFC after:	1 week

1 files changed, 14 insertions, 12 deletions

diff --git a/sys/cam/scsi/scsi_da.c b/sys/cam/scsi/scsi_da.c
index b38258b..1643e9c 100644
--- a/sys/cam/scsi/scsi_da.c
+++ b/sys/cam/scsi/scsi_da.c
@@ -211,7 +211,7 @@ struct da_softc {
 	int	 delete_running;
 	int	 delete_available;	/* Delete methods possibly available */
 	uint32_t		unmap_max_ranges;
-	uint32_t		unmap_max_lba; /* Max LBAs in a single range */
+	uint32_t		unmap_max_lba; /* Max LBAs in UNMAP req */
 	uint64_t		ws_max_blks;
 	da_delete_methods	delete_method;
 	da_delete_func_t	*delete_func;
@@ -1854,7 +1854,7 @@ dadeletemaxsize(struct da_softc *softc, da_delete_methods delete_method)
 
 	switch(delete_method) {
 	case DA_DELETE_UNMAP:
-		sectors = (off_t)softc->unmap_max_lba * softc->unmap_max_ranges;
+		sectors = (off_t)softc->unmap_max_lba;
 		break;
 	case DA_DELETE_ATA_TRIM:
 		sectors = (off_t)ATA_DSM_RANGE_MAX * softc->trim_max_ranges;
@@ -2526,6 +2526,7 @@ da_delete_unmap(struct cam_periph *periph, union ccb *ccb, struct bio *bp)
 	struct bio *bp1;
 	uint8_t *buf = softc->unmap_buf;
 	uint64_t lba, lastlba = (uint64_t)-1;
+	uint64_t totalcount = 0;
 	uint64_t count;
 	uint32_t lastcount = 0, c;
 	uint32_t off, ranges = 0;
@@ -2552,41 +2553,42 @@ da_delete_unmap(struct cam_periph *periph, union ccb *ccb, struct bio *bp)
 
 		/* Try to extend the previous range. */
 		if (lba == lastlba) {
-			c = min(count, softc->unmap_max_lba - lastcount);
+			c = omin(count, UNMAP_RANGE_MAX - lastcount);
 			lastcount += c;
 			off = ((ranges - 1) * UNMAP_RANGE_SIZE) +
 			      UNMAP_HEAD_SIZE;
 			scsi_ulto4b(lastcount, &buf[off + 8]);
 			count -= c;
 			lba +=c;
+			totalcount += c;
 		}
 
 		while (count > 0) {
-			if (ranges > softc->unmap_max_ranges) {
+			c = omin(count, UNMAP_RANGE_MAX);
+			if (totalcount + c > softc->unmap_max_lba ||
+			    ranges >= softc->unmap_max_ranges) {
 				xpt_print(periph->path,
-				    "%s issuing short delete %d > %d\n",
+				    "%s issuing short delete %ld > %ld"
+				    "|| %d >= %d",
 				    da_delete_method_desc[softc->delete_method],
+				    totalcount + c, softc->unmap_max_lba,
 				    ranges, softc->unmap_max_ranges);
 				break;
 			}
-			c = min(count, softc->unmap_max_lba);
 			off = (ranges * UNMAP_RANGE_SIZE) + UNMAP_HEAD_SIZE;
 			scsi_u64to8b(lba, &buf[off + 0]);
 			scsi_ulto4b(c, &buf[off + 8]);
 			lba += c;
+			totalcount += c;
 			ranges++;
 			count -= c;
 			lastcount = c;
 		}
 		lastlba = lba;
 		bp1 = bioq_first(&softc->delete_queue);
-		/*
-		 * Assume no range extension on the next loop iteration to
-		 * avoid issuing a short delete.
-		 */
 		if (bp1 == NULL || ranges >= softc->unmap_max_ranges ||
-		    bp1->bio_bcount / softc->params.secsize >
-		    softc->unmap_max_lba * (softc->unmap_max_ranges - ranges))
+		    totalcount + bp1->bio_bcount /
+		    softc->params.secsize > softc->unmap_max_lba)
 			break;
 	} while (1);
 	scsi_ulto2b(ranges * 16 + 6, &buf[0]);