1 files changed, 40 insertions, 54 deletions

diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index 0b7d8787f785..ca73c46931c0 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -67,11 +67,17 @@ static void sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
  * @buf: Buffer to use for the reply
  * @buflen: the buffer size
  * @lba: Start LBA of the report
+ * @partial: Do partial report
  *
  * For internal use during device validation.
+ * Using partial=true can significantly speed up execution of a report zones
+ * command because the disk does not have to count all possible report matching
+ * zones and will only report the count of zones fitting in the command reply
+ * buffer.
  */
 static int sd_zbc_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
-			       unsigned int buflen, sector_t lba)
+			       unsigned int buflen, sector_t lba,
+			       bool partial)
 {
 	struct scsi_device *sdp = sdkp->device;
 	const int timeout = sdp->request_queue->rq_timeout;
@@ -85,6 +91,8 @@ static int sd_zbc_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
 	cmd[1] = ZI_REPORT_ZONES;
 	put_unaligned_be64(lba, &cmd[2]);
 	put_unaligned_be32(buflen, &cmd[10]);
+	if (partial)
+		cmd[14] = ZBC_REPORT_ZONE_PARTIAL;
 	memset(buf, 0, buflen);
 
 	result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
@@ -350,60 +358,25 @@ static int sd_zbc_check_zoned_characteristics(struct scsi_disk *sdkp,
 	return 0;
 }
 
-/**
- * sd_zbc_check_capacity - Check reported capacity.
- * @sdkp: Target disk
- * @buf: Buffer to use for commands
- *
- * ZBC drive may report only the capacity of the first conventional zones at
- * LBA 0. This is indicated by the RC_BASIS field of the read capacity reply.
- * Check this here. If the disk reported only its conventional zones capacity,
- * get the total capacity by doing a report zones.
- */
-static int sd_zbc_check_capacity(struct scsi_disk *sdkp, unsigned char *buf)
-{
-	sector_t lba;
-	int ret;
-
-	if (sdkp->rc_basis != 0)
-		return 0;
-
-	/* Do a report zone to get the maximum LBA to check capacity */
-	ret = sd_zbc_report_zones(sdkp, buf, SD_BUF_SIZE, 0);
-	if (ret)
-		return ret;
-
-	/* The max_lba field is the capacity of this device */
-	lba = get_unaligned_be64(&buf[8]);
-	if (lba + 1 == sdkp->capacity)
-		return 0;
-
-	if (sdkp->first_scan)
-		sd_printk(KERN_WARNING, sdkp,
-			  "Changing capacity from %llu to max LBA+1 %llu\n",
-			  (unsigned long long)sdkp->capacity,
-			  (unsigned long long)lba + 1);
-	sdkp->capacity = lba + 1;
-
-	return 0;
-}
-
 #define SD_ZBC_BUF_SIZE 131072U
 
 /**
- * sd_zbc_check_zone_size - Check the device zone sizes
+ * sd_zbc_check_zones - Check the device capacity and zone sizes
  * @sdkp: Target disk
  *
- * Check that all zones of the device are equal. The last zone can however
- * be smaller. The zone size must also be a power of two number of LBAs.
+ * Check that the device capacity as reported by READ CAPACITY matches the
+ * max_lba value (plus one)of the report zones command reply. Also check that
+ * all zones of the device have an equal size, only allowing the last zone of
+ * the disk to have a smaller size (runt zone). The zone size must also be a
+ * power of two.
  *
  * Returns the zone size in number of blocks upon success or an error code
  * upon failure.
  */
-static s64 sd_zbc_check_zone_size(struct scsi_disk *sdkp)
+static s64 sd_zbc_check_zones(struct scsi_disk *sdkp)
 {
 	u64 zone_blocks = 0;
-	sector_t block = 0;
+	sector_t max_lba, block = 0;
 	unsigned char *buf;
 	unsigned char *rec;
 	unsigned int buf_len;
@@ -416,11 +389,28 @@ static s64 sd_zbc_check_zone_size(struct scsi_disk *sdkp)
 	if (!buf)
 		return -ENOMEM;
 
-	/* Do a report zone to get the same field */
-	ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, 0);
+	/* Do a report zone to get max_lba and the same field */
+	ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, 0, false);
 	if (ret)
 		goto out_free;
 
+	if (sdkp->rc_basis == 0) {
+		/* The max_lba field is the capacity of this device */
+		max_lba = get_unaligned_be64(&buf[8]);
+		if (sdkp->capacity != max_lba + 1) {
+			if (sdkp->first_scan)
+				sd_printk(KERN_WARNING, sdkp,
+					"Changing capacity from %llu to max LBA+1 %llu\n",
+					(unsigned long long)sdkp->capacity,
+					(unsigned long long)max_lba + 1);
+			sdkp->capacity = max_lba + 1;
+		}
+	}
+
+	/*
+	 * Check same field: for any value other than 0, we know that all zones
+	 * have the same size.
+	 */
 	same = buf[4] & 0x0f;
 	if (same > 0) {
 		rec = &buf[64];
@@ -458,7 +448,7 @@ static s64 sd_zbc_check_zone_size(struct scsi_disk *sdkp)
 
 		if (block < sdkp->capacity) {
 			ret = sd_zbc_report_zones(sdkp, buf,
-						  SD_ZBC_BUF_SIZE, block);
+						  SD_ZBC_BUF_SIZE, block, true);
 			if (ret)
 				goto out_free;
 		}
@@ -574,7 +564,8 @@ sd_zbc_setup_seq_zones_bitmap(struct scsi_disk *sdkp, u32 zone_shift,
 		goto out;
 
 	while (lba < sdkp->capacity) {
-		ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, lba);
+		ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE,
+					  lba, true);
 		if (ret)
 			goto out;
 		lba = sd_zbc_get_seq_zones(sdkp, buf, SD_ZBC_BUF_SIZE,
@@ -692,16 +683,11 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
 	if (ret)
 		goto err;
 
-	/* Check capacity */
-	ret = sd_zbc_check_capacity(sdkp, buf);
-	if (ret)
-		goto err;
-
 	/*
 	 * Check zone size: only devices with a constant zone size (except
 	 * an eventual last runt zone) that is a power of 2 are supported.
 	 */
-	zone_blocks = sd_zbc_check_zone_size(sdkp);
+	zone_blocks = sd_zbc_check_zones(sdkp);
 	ret = -EFBIG;
 	if (zone_blocks != (u32)zone_blocks)
 		goto err;