target: move write_same to struct spc_ops

Add spc_ops->execute_write_same() caller for ->execute_cmd() setup,
and update IBLOCK backends to use it.

(nab: add export of spc_get_write_same_sectors symbol)
(roland: Carry forward: Fix range calculation in WRITE SAME emulation
         when num blocks == 0)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index 863c962..ee70cc9 100644 (file)
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -327,6 +327,23 @@ static int iblock_do_discard(struct se_device *dev, sector_t lba, u32 range)
        return blkdev_issue_discard(bd, lba, range, GFP_KERNEL, barrier);
 }
 
+static int iblock_execute_write_same(struct se_cmd *cmd)
+{
+       struct iblock_dev *ibd = cmd->se_dev->dev_ptr;
+       int ret;
+
+       ret = blkdev_issue_discard(ibd->ibd_bd, cmd->t_task_lba,
+                                  spc_get_write_same_sectors(cmd), GFP_KERNEL,
+                                  0);
+       if (ret < 0) {
+               pr_debug("blkdev_issue_discard() failed for WRITE_SAME\n");
+               return ret;
+       }
+
+       target_complete_cmd(cmd, GOOD);
+       return 0;
+}
+
 enum {
        Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 };
@@ -669,6 +686,7 @@ static void iblock_bio_done(struct bio *bio, int err)
 static struct spc_ops iblock_spc_ops = {
        .execute_rw             = iblock_execute_rw,
        .execute_sync_cache     = iblock_execute_sync_cache,
+       .execute_write_same     = iblock_execute_write_same,
 };
 
 static int iblock_parse_cdb(struct se_cmd *cmd)

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 377c510..146ca37 100644 (file)
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -156,24 +156,9 @@ err:
        return ret;
 }
 
-/*
- * Used for TCM/IBLOCK and TCM/FILEIO for block/blk-lib.c level discard support.
- * Note this is not used for TCM/pSCSI passthrough
- */
-static int sbc_emulate_write_same(struct se_cmd *cmd)
+int spc_get_write_same_sectors(struct se_cmd *cmd)
 {
-       struct se_device *dev = cmd->se_dev;
-       sector_t range;
-       sector_t lba = cmd->t_task_lba;
        u32 num_blocks;
-       int ret;
-
-       if (!dev->transport->do_discard) {
-               pr_err("WRITE_SAME emulation not supported"
-                               " for: %s\n", dev->transport->name);
-               cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
-               return -ENOSYS;
-       }
 
        if (cmd->t_task_cdb[0] == WRITE_SAME)
                num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
@@ -186,23 +171,13 @@ static int sbc_emulate_write_same(struct se_cmd *cmd)
         * Use the explicit range when non zero is supplied, otherwise calculate
         * the remaining range based on ->get_blocks() - starting LBA.
         */
-       if (num_blocks != 0)
-               range = num_blocks;
-       else
-               range = (dev->transport->get_blocks(dev) - lba) + 1;
+       if (num_blocks)
+               return num_blocks;
 
-       pr_debug("WRITE_SAME UNMAP: LBA: %llu Range: %llu\n",
-                (unsigned long long)lba, (unsigned long long)range);
-
-       ret = dev->transport->do_discard(dev, lba, range);
-       if (ret < 0) {
-               pr_debug("blkdev_issue_discard() failed for WRITE_SAME\n");
-               return ret;
-       }
-
-       target_complete_cmd(cmd, GOOD);
-       return 0;
+       return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
+               cmd->t_task_lba + 1;
 }
+EXPORT_SYMBOL(spc_get_write_same_sectors);
 
 static int sbc_emulate_verify(struct se_cmd *cmd)
 {
@@ -488,6 +463,9 @@ int sbc_parse_cdb(struct se_cmd *cmd, struct spc_ops *ops)
                                cmd->se_cmd_flags |= SCF_FUA;
                        break;
                case WRITE_SAME_32:
+                       if (!ops->execute_write_same)
+                               goto out_unsupported_cdb;
+
                        sectors = transport_get_sectors_32(cdb);
                        if (!sectors) {
                                pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
@@ -500,7 +478,7 @@ int sbc_parse_cdb(struct se_cmd *cmd, struct spc_ops *ops)
 
                        if (sbc_write_same_supported(dev, &cdb[10]) < 0)
                                goto out_unsupported_cdb;
-                       cmd->execute_cmd = sbc_emulate_write_same;
+                       cmd->execute_cmd = ops->execute_write_same;
                        break;
                default:
                        pr_err("VARIABLE_LENGTH_CMD service action"
@@ -559,6 +537,9 @@ int sbc_parse_cdb(struct se_cmd *cmd, struct spc_ops *ops)
                cmd->execute_cmd = sbc_emulate_unmap;
                break;
        case WRITE_SAME_16:
+               if (!ops->execute_write_same)
+                       goto out_unsupported_cdb;
+
                sectors = transport_get_sectors_16(cdb);
                if (!sectors) {
                        pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
@@ -570,9 +551,12 @@ int sbc_parse_cdb(struct se_cmd *cmd, struct spc_ops *ops)
 
                if (sbc_write_same_supported(dev, &cdb[1]) < 0)
                        goto out_unsupported_cdb;
-               cmd->execute_cmd = sbc_emulate_write_same;
+               cmd->execute_cmd = ops->execute_write_same;
                break;
        case WRITE_SAME:
+               if (!ops->execute_write_same)
+                       goto out_unsupported_cdb;
+
                sectors = transport_get_sectors_10(cdb);
                if (!sectors) {
                        pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
@@ -588,7 +572,7 @@ int sbc_parse_cdb(struct se_cmd *cmd, struct spc_ops *ops)
                 */
                if (sbc_write_same_supported(dev, &cdb[1]) < 0)
                        goto out_unsupported_cdb;
-               cmd->execute_cmd = sbc_emulate_write_same;
+               cmd->execute_cmd = ops->execute_write_same;
                break;
        case VERIFY:
                size = 0;

diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 5797b11..fbc6a1b 100644 (file)
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -42,6 +42,7 @@ struct se_subsystem_api {
 struct spc_ops {
        int (*execute_rw)(struct se_cmd *cmd);
        int (*execute_sync_cache)(struct se_cmd *cmd);
+       int (*execute_write_same)(struct se_cmd *cmd);
 };
 
 int    transport_subsystem_register(struct se_subsystem_api *);
@@ -55,6 +56,7 @@ void  target_complete_cmd(struct se_cmd *, u8);
 
 int    sbc_parse_cdb(struct se_cmd *cmd, struct spc_ops *ops);
 int    spc_parse_cdb(struct se_cmd *cmd, unsigned int *size);
+int    spc_get_write_same_sectors(struct se_cmd *cmd);
 
 void   transport_set_vpd_proto_id(struct t10_vpd *, unsigned char *);
 int    transport_set_vpd_assoc(struct t10_vpd *, unsigned char *);