target: Add sbc_execute_unmap() helper

iblock_execute_unmap() and fd_execute_unmap share a lot of code.
Add sbc_execute_unmap() helper to remove duplicated code for
iblock_execute_unmap() and fd_execute_unmap().

Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 85 insertions, 0 deletions

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 60d4b5185f32..bbc5b0ee2bdc 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -596,3 +596,88 @@ u32 sbc_get_device_type(struct se_device *dev)
         return TYPE_DISK;
 }
 EXPORT_SYMBOL(sbc_get_device_type);
+
+sense_reason_t
+sbc_execute_unmap(struct se_cmd *cmd,
+        sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
+                                      sector_t, sector_t),
+        void *priv)
+{
+        struct se_device *dev = cmd->se_dev;
+        unsigned char *buf, *ptr = NULL;
+        sector_t lba;
+        int size;
+        u32 range;
+        sense_reason_t ret = 0;
+        int dl, bd_dl;
+
+        /* We never set ANC_SUP */
+        if (cmd->t_task_cdb[1])
+                return TCM_INVALID_CDB_FIELD;
+
+        if (cmd->data_length == 0) {
+                target_complete_cmd(cmd, SAM_STAT_GOOD);
+                return 0;
+        }
+
+        if (cmd->data_length < 8) {
+                pr_warn("UNMAP parameter list length %u too small\n",
+                        cmd->data_length);
+                return TCM_PARAMETER_LIST_LENGTH_ERROR;
+        }
+
+        buf = transport_kmap_data_sg(cmd);
+        if (!buf)
+                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+        dl = get_unaligned_be16(&buf[0]);
+        bd_dl = get_unaligned_be16(&buf[2]);
+
+        size = cmd->data_length - 8;
+        if (bd_dl > size)
+                pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
+                        cmd->data_length, bd_dl);
+        else
+                size = bd_dl;
+
+        if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
+                ret = TCM_INVALID_PARAMETER_LIST;
+                goto err;
+        }
+
+        /* First UNMAP block descriptor starts at 8 byte offset */
+        ptr = &buf[8];
+        pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
+                " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
+
+        while (size >= 16) {
+                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);
+
+                if (range > dev->dev_attrib.max_unmap_lba_count) {
+                        ret = TCM_INVALID_PARAMETER_LIST;
+                        goto err;
+                }
+
+                if (lba + range > dev->transport->get_blocks(dev) + 1) {
+                        ret = TCM_ADDRESS_OUT_OF_RANGE;
+                        goto err;
+                }
+
+                ret = do_unmap_fn(cmd, priv, lba, range);
+                if (ret)
+                        goto err;
+
+                ptr += 16;
+                size -= 16;
+        }
+
+err:
+        transport_kunmap_data_sg(cmd);
+        if (!ret)
+                target_complete_cmd(cmd, GOOD);
+        return ret;
+}
+EXPORT_SYMBOL(sbc_execute_unmap);