1 files changed, 179 insertions, 23 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 12f6fdfc1147..352bc77b7c88 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -99,6 +99,7 @@ MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
 #endif
 
 static void sd_config_discard(struct scsi_disk *, unsigned int);
+static void sd_config_write_same(struct scsi_disk *);
 static int  sd_revalidate_disk(struct gendisk *);
 static void sd_unlock_native_capacity(struct gendisk *disk);
 static int  sd_probe(struct device *);
@@ -395,6 +396,45 @@ sd_store_max_medium_access_timeouts(struct device *dev,
         return err ? err : count;
 }
 
+static ssize_t
+sd_show_write_same_blocks(struct device *dev, struct device_attribute *attr,
+                          char *buf)
+{
+        struct scsi_disk *sdkp = to_scsi_disk(dev);
+
+        return snprintf(buf, 20, "%u\n", sdkp->max_ws_blocks);
+}
+
+static ssize_t
+sd_store_write_same_blocks(struct device *dev, struct device_attribute *attr,
+                           const char *buf, size_t count)
+{
+        struct scsi_disk *sdkp = to_scsi_disk(dev);
+        struct scsi_device *sdp = sdkp->device;
+        unsigned long max;
+        int err;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EACCES;
+
+        if (sdp->type != TYPE_DISK)
+                return -EINVAL;
+
+        err = kstrtoul(buf, 10, &max);
+
+        if (err)
+                return err;
+
+        if (max == 0)
+                sdp->no_write_same = 1;
+        else if (max <= SD_MAX_WS16_BLOCKS)
+                sdkp->max_ws_blocks = max;
+
+        sd_config_write_same(sdkp);
+
+        return count;
+}
+
 static struct device_attribute sd_disk_attrs[] = {
         __ATTR(cache_type, S_IRUGO|S_IWUSR, sd_show_cache_type,
                sd_store_cache_type),
@@ -410,6 +450,8 @@ static struct device_attribute sd_disk_attrs[] = {
         __ATTR(thin_provisioning, S_IRUGO, sd_show_thin_provisioning, NULL),
         __ATTR(provisioning_mode, S_IRUGO|S_IWUSR, sd_show_provisioning_mode,
                sd_store_provisioning_mode),
+        __ATTR(max_write_same_blocks, S_IRUGO|S_IWUSR,
+               sd_show_write_same_blocks, sd_store_write_same_blocks),
         __ATTR(max_medium_access_timeouts, S_IRUGO|S_IWUSR,
                sd_show_max_medium_access_timeouts,
                sd_store_max_medium_access_timeouts),
@@ -561,19 +603,23 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
                 return;
 
         case SD_LBP_UNMAP:
-                max_blocks = min_not_zero(sdkp->max_unmap_blocks, 0xffffffff);
+                max_blocks = min_not_zero(sdkp->max_unmap_blocks,
+                                          (u32)SD_MAX_WS16_BLOCKS);
                 break;
 
         case SD_LBP_WS16:
-                max_blocks = min_not_zero(sdkp->max_ws_blocks, 0xffffffff);
+                max_blocks = min_not_zero(sdkp->max_ws_blocks,
+                                          (u32)SD_MAX_WS16_BLOCKS);
                 break;
 
         case SD_LBP_WS10:
-                max_blocks = min_not_zero(sdkp->max_ws_blocks, (u32)0xffff);
+                max_blocks = min_not_zero(sdkp->max_ws_blocks,
+                                          (u32)SD_MAX_WS10_BLOCKS);
                 break;
 
         case SD_LBP_ZERO:
-                max_blocks = min_not_zero(sdkp->max_ws_blocks, (u32)0xffff);
+                max_blocks = min_not_zero(sdkp->max_ws_blocks,
+                                          (u32)SD_MAX_WS10_BLOCKS);
                 q->limits.discard_zeroes_data = 1;
                 break;
         }
@@ -583,29 +629,26 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
 }
 
 /**
- * scsi_setup_discard_cmnd - unmap blocks on thinly provisioned device
+ * sd_setup_discard_cmnd - unmap blocks on thinly provisioned device
  * @sdp: scsi device to operate one
  * @rq: Request to prepare
  *
  * Will issue either UNMAP or WRITE SAME(16) depending on preference
  * indicated by target device.
  **/
-static int scsi_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq)
+static int sd_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq)
 {
         struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
-        struct bio *bio = rq->bio;
-        sector_t sector = bio->bi_sector;
-        unsigned int nr_sectors = bio_sectors(bio);
+        sector_t sector = blk_rq_pos(rq);
+        unsigned int nr_sectors = blk_rq_sectors(rq);
+        unsigned int nr_bytes = blk_rq_bytes(rq);
         unsigned int len;
         int ret;
         char *buf;
         struct page *page;
 
-        if (sdkp->device->sector_size == 4096) {
-                sector >>= 3;
-                nr_sectors >>= 3;
-        }
-
+        sector >>= ilog2(sdp->sector_size) - 9;
+        nr_sectors >>= ilog2(sdp->sector_size) - 9;
         rq->timeout = SD_TIMEOUT;
 
         memset(rq->cmd, 0, rq->cmd_len);
@@ -660,6 +703,7 @@ static int scsi_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq)
         blk_add_request_payload(rq, page, len);
         ret = scsi_setup_blk_pc_cmnd(sdp, rq);
         rq->buffer = page_address(page);
+        rq->__data_len = nr_bytes;
 
 out:
         if (ret != BLKPREP_OK) {
@@ -669,6 +713,83 @@ out:
         return ret;
 }
 
+static void sd_config_write_same(struct scsi_disk *sdkp)
+{
+        struct request_queue *q = sdkp->disk->queue;
+        unsigned int logical_block_size = sdkp->device->sector_size;
+        unsigned int blocks = 0;
+
+        if (sdkp->device->no_write_same) {
+                sdkp->max_ws_blocks = 0;
+                goto out;
+        }
+
+        /* Some devices can not handle block counts above 0xffff despite
+         * supporting WRITE SAME(16). Consequently we default to 64k
+         * blocks per I/O unless the device explicitly advertises a
+         * bigger limit.
+         */
+        if (sdkp->max_ws_blocks == 0)
+                sdkp->max_ws_blocks = SD_MAX_WS10_BLOCKS;
+
+        if (sdkp->ws16 || sdkp->max_ws_blocks > SD_MAX_WS10_BLOCKS)
+                blocks = min_not_zero(sdkp->max_ws_blocks,
+                                      (u32)SD_MAX_WS16_BLOCKS);
+        else
+                blocks = min_not_zero(sdkp->max_ws_blocks,
+                                      (u32)SD_MAX_WS10_BLOCKS);
+
+out:
+        blk_queue_max_write_same_sectors(q, blocks * (logical_block_size >> 9));
+}
+
+/**
+ * sd_setup_write_same_cmnd - write the same data to multiple blocks
+ * @sdp: scsi device to operate one
+ * @rq: Request to prepare
+ *
+ * Will issue either WRITE SAME(10) or WRITE SAME(16) depending on
+ * preference indicated by target device.
+ **/
+static int sd_setup_write_same_cmnd(struct scsi_device *sdp, struct request *rq)
+{
+        struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
+        struct bio *bio = rq->bio;
+        sector_t sector = blk_rq_pos(rq);
+        unsigned int nr_sectors = blk_rq_sectors(rq);
+        unsigned int nr_bytes = blk_rq_bytes(rq);
+        int ret;
+
+        if (sdkp->device->no_write_same)
+                return BLKPREP_KILL;
+
+        BUG_ON(bio_offset(bio) || bio_iovec(bio)->bv_len != sdp->sector_size);
+
+        sector >>= ilog2(sdp->sector_size) - 9;
+        nr_sectors >>= ilog2(sdp->sector_size) - 9;
+
+        rq->__data_len = sdp->sector_size;
+        rq->timeout = SD_WRITE_SAME_TIMEOUT;
+        memset(rq->cmd, 0, rq->cmd_len);
+
+        if (sdkp->ws16 || sector > 0xffffffff || nr_sectors > 0xffff) {
+                rq->cmd_len = 16;
+                rq->cmd[0] = WRITE_SAME_16;
+                put_unaligned_be64(sector, &rq->cmd[2]);
+                put_unaligned_be32(nr_sectors, &rq->cmd[10]);
+        } else {
+                rq->cmd_len = 10;
+                rq->cmd[0] = WRITE_SAME;
+                put_unaligned_be32(sector, &rq->cmd[2]);
+                put_unaligned_be16(nr_sectors, &rq->cmd[7]);
+        }
+
+        ret = scsi_setup_blk_pc_cmnd(sdp, rq);
+        rq->__data_len = nr_bytes;
+
+        return ret;
+}
+
 static int scsi_setup_flush_cmnd(struct scsi_device *sdp, struct request *rq)
 {
         rq->timeout = SD_FLUSH_TIMEOUT;
@@ -712,7 +833,10 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
          * block PC requests to make life easier.
          */
         if (rq->cmd_flags & REQ_DISCARD) {
-                ret = scsi_setup_discard_cmnd(sdp, rq);
+                ret = sd_setup_discard_cmnd(sdp, rq);
+                goto out;
+        } else if (rq->cmd_flags & REQ_WRITE_SAME) {
+                ret = sd_setup_write_same_cmnd(sdp, rq);
                 goto out;
         } else if (rq->cmd_flags & REQ_FLUSH) {
                 ret = scsi_setup_flush_cmnd(sdp, rq);
@@ -1482,12 +1606,21 @@ static int sd_done(struct scsi_cmnd *SCpnt)
         unsigned int good_bytes = result ? 0 : scsi_bufflen(SCpnt);
         struct scsi_sense_hdr sshdr;
         struct scsi_disk *sdkp = scsi_disk(SCpnt->request->rq_disk);
+        struct request *req = SCpnt->request;
         int sense_valid = 0;
         int sense_deferred = 0;
         unsigned char op = SCpnt->cmnd[0];
+        unsigned char unmap = SCpnt->cmnd[1] & 8;
 
-        if ((SCpnt->request->cmd_flags & REQ_DISCARD) && !result)
-                scsi_set_resid(SCpnt, 0);
+        if (req->cmd_flags & REQ_DISCARD || req->cmd_flags & REQ_WRITE_SAME) {
+                if (!result) {
+                        good_bytes = blk_rq_bytes(req);
+                        scsi_set_resid(SCpnt, 0);
+                } else {
+                        good_bytes = 0;
+                        scsi_set_resid(SCpnt, blk_rq_bytes(req));
+                }
+        }
 
         if (result) {
                 sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
@@ -1536,9 +1669,25 @@ static int sd_done(struct scsi_cmnd *SCpnt)
                 if (sshdr.asc == 0x10)  /* DIX: Host detected corruption */
                         good_bytes = sd_completed_bytes(SCpnt);
                 /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
-                if ((sshdr.asc == 0x20 || sshdr.asc == 0x24) &&
-                    (op == UNMAP || op == WRITE_SAME_16 || op == WRITE_SAME))
-                        sd_config_discard(sdkp, SD_LBP_DISABLE);
+                if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {
+                        switch (op) {
+                        case UNMAP:
+                                sd_config_discard(sdkp, SD_LBP_DISABLE);
+                                break;
+                        case WRITE_SAME_16:
+                        case WRITE_SAME:
+                                if (unmap)
+                                        sd_config_discard(sdkp, SD_LBP_DISABLE);
+                                else {
+                                        sdkp->device->no_write_same = 1;
+                                        sd_config_write_same(sdkp);
+
+                                        good_bytes = 0;
+                                        req->__data_len = blk_rq_bytes(req);
+                                        req->cmd_flags |= REQ_QUIET;
+                                }
+                        }
+                }
                 break;
         default:
                 break;
@@ -2374,9 +2523,7 @@ static void sd_read_block_limits(struct scsi_disk *sdkp)
         if (buffer[3] == 0x3c) {
                 unsigned int lba_count, desc_count;
 
-                sdkp->max_ws_blocks =
-                        (u32) min_not_zero(get_unaligned_be64(&buffer[36]),
-                                           (u64)0xffffffff);
+                sdkp->max_ws_blocks = (u32)get_unaligned_be64(&buffer[36]);
 
                 if (!sdkp->lbpme)
                         goto out;
@@ -2469,6 +2616,13 @@ static void sd_read_block_provisioning(struct scsi_disk *sdkp)
         kfree(buffer);
 }
 
+static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer)
+{
+        if (scsi_report_opcode(sdkp->device, buffer, SD_BUF_SIZE,
+                               WRITE_SAME_16))
+                sdkp->ws16 = 1;
+}
+
 static int sd_try_extended_inquiry(struct scsi_device *sdp)
 {
         /*
@@ -2528,6 +2682,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
                 sd_read_write_protect_flag(sdkp, buffer);
                 sd_read_cache_type(sdkp, buffer);
                 sd_read_app_tag_own(sdkp, buffer);
+                sd_read_write_same(sdkp, buffer);
         }
 
         sdkp->first_scan = 0;
@@ -2545,6 +2700,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
         blk_queue_flush(sdkp->disk->queue, flush);
 
         set_capacity(disk, sdkp->capacity);
+        sd_config_write_same(sdkp);
         kfree(buffer);
 
  out: