target: move unmap to struct spc_ops

Having all the unmap payload parsing in the backed is a bit ugly, but until
more drivers support it and we can find a good interface for all of them
that seems the way to go.

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

2 files changed, 49 insertions, 63 deletions

diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index ee70cc9f6a64..8a12e29009c1 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -40,6 +40,7 @@
 #include <linux/module.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_host.h>
+#include <asm/unaligned.h>
 
 #include <target/target_core_base.h>
 #include <target/target_core_backend.h>
@@ -318,13 +319,52 @@ static int iblock_execute_sync_cache(struct se_cmd *cmd)
         return 0;
 }
 
-static int iblock_do_discard(struct se_device *dev, sector_t lba, u32 range)
+static int iblock_execute_unmap(struct se_cmd *cmd)
 {
+        struct se_device *dev = cmd->se_dev;
         struct iblock_dev *ibd = dev->dev_ptr;
-        struct block_device *bd = ibd->ibd_bd;
-        int barrier = 0;
+        unsigned char *buf, *ptr = NULL;
+        unsigned char *cdb = &cmd->t_task_cdb[0];
+        sector_t lba;
+        unsigned int size = cmd->data_length, range;
+        int ret = 0, offset;
+        unsigned short dl, bd_dl;
+
+        /* First UNMAP block descriptor starts at 8 byte offset */
+        offset = 8;
+        size -= 8;
+        dl = get_unaligned_be16(&cdb[0]);
+        bd_dl = get_unaligned_be16(&cdb[2]);
+
+        buf = transport_kmap_data_sg(cmd);
+
+        ptr = &buf[offset];
+        pr_debug("UNMAP: Sub: %s Using dl: %hu bd_dl: %hu size: %hu"
+                " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
+
+        while (size) {
+                lba = get_unaligned_be64(&ptr[0]);
+                range = get_unaligned_be32(&ptr[8]);
+                pr_debug("UNMAP: Using lba: %llu and range: %u\n",
+                                 (unsigned long long)lba, range);
+
+                ret = blkdev_issue_discard(ibd->ibd_bd, lba, range,
+                                           GFP_KERNEL, 0);
+                if (ret < 0) {
+                        pr_err("blkdev_issue_discard() failed: %d\n",
+                                        ret);
+                        goto err;
+                }
+
+                ptr += 16;
+                size -= 16;
+        }
 
-        return blkdev_issue_discard(bd, lba, range, GFP_KERNEL, barrier);
+err:
+        transport_kunmap_data_sg(cmd);
+        if (!ret)
+                target_complete_cmd(cmd, GOOD);
+        return ret;
 }
 
 static int iblock_execute_write_same(struct se_cmd *cmd)
@@ -687,6 +727,7 @@ 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,
+        .execute_unmap          = iblock_execute_unmap,
 };
 
 static int iblock_parse_cdb(struct se_cmd *cmd)
@@ -706,7 +747,6 @@ static struct se_subsystem_api iblock_template = {
         .create_virtdevice      = iblock_create_virtdevice,
         .free_device            = iblock_free_device,
         .parse_cdb              = iblock_parse_cdb,
-        .do_discard             = iblock_do_discard,
         .check_configfs_dev_params = iblock_check_configfs_dev_params,
         .set_configfs_dev_params = iblock_set_configfs_dev_params,
         .show_configfs_dev_params = iblock_show_configfs_dev_params,
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 146ca372489b..a9dd9469e3bd 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -99,63 +99,6 @@ static int sbc_emulate_readcapacity_16(struct se_cmd *cmd)
         return 0;
 }
 
-/*
- * 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_unmap(struct se_cmd *cmd)
-{
-        struct se_device *dev = cmd->se_dev;
-        unsigned char *buf, *ptr = NULL;
-        unsigned char *cdb = &cmd->t_task_cdb[0];
-        sector_t lba;
-        unsigned int size = cmd->data_length, range;
-        int ret = 0, offset;
-        unsigned short dl, bd_dl;
-
-        if (!dev->transport->do_discard) {
-                pr_err("UNMAP emulation not supported for: %s\n",
-                                dev->transport->name);
-                cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
-                return -ENOSYS;
-        }
-
-        /* First UNMAP block descriptor starts at 8 byte offset */
-        offset = 8;
-        size -= 8;
-        dl = get_unaligned_be16(&cdb[0]);
-        bd_dl = get_unaligned_be16(&cdb[2]);
-
-        buf = transport_kmap_data_sg(cmd);
-
-        ptr = &buf[offset];
-        pr_debug("UNMAP: Sub: %s Using dl: %hu bd_dl: %hu size: %hu"
-                " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
-
-        while (size) {
-                lba = get_unaligned_be64(&ptr[0]);
-                range = get_unaligned_be32(&ptr[8]);
-                pr_debug("UNMAP: Using lba: %llu and range: %u\n",
-                                 (unsigned long long)lba, range);
-
-                ret = dev->transport->do_discard(dev, lba, range);
-                if (ret < 0) {
-                        pr_err("blkdev_issue_discard() failed: %d\n",
-                                        ret);
-                        goto err;
-                }
-
-                ptr += 16;
-                size -= 16;
-        }
-
-err:
-        transport_kunmap_data_sg(cmd);
-        if (!ret)
-                target_complete_cmd(cmd, GOOD);
-        return ret;
-}
-
 int spc_get_write_same_sectors(struct se_cmd *cmd)
 {
         u32 num_blocks;
@@ -533,8 +476,11 @@ int sbc_parse_cdb(struct se_cmd *cmd, struct spc_ops *ops)
                 cmd->execute_cmd = ops->execute_sync_cache;
                 break;
         case UNMAP:
+                if (!ops->execute_unmap)
+                        goto out_unsupported_cdb;
+
                 size = get_unaligned_be16(&cdb[7]);
-                cmd->execute_cmd = sbc_emulate_unmap;
+                cmd->execute_cmd = ops->execute_unmap;
                 break;
         case WRITE_SAME_16:
                 if (!ops->execute_write_same)