diff options
| -rw-r--r-- | drivers/target/target_core_device.c | 1 | ||||
| -rw-r--r-- | drivers/target/target_core_sbc.c | 197 | ||||
| -rw-r--r-- | include/target/target_core_base.h | 1 |
3 files changed, 198 insertions, 1 deletions
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index 0b5f86806f1d..f3dc1f5fc41c 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -1413,6 +1413,7 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name) spin_lock_init(&dev->se_port_lock); spin_lock_init(&dev->se_tmr_lock); spin_lock_init(&dev->qf_cmd_lock); + sema_init(&dev->caw_sem, 1); atomic_set(&dev->dev_ordered_id, 0); INIT_LIST_HEAD(&dev->t10_wwn.t10_vpd_list); spin_lock_init(&dev->t10_wwn.t10_vpd_lock); diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index 5569b3697103..dfb6603eab4d 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -25,6 +25,7 @@ #include <linux/ratelimit.h> #include <asm/unaligned.h> #include <scsi/scsi.h> +#include <scsi/scsi_tcq.h> #include <target/target_core_base.h> #include <target/target_core_backend.h> @@ -344,6 +345,177 @@ sbc_execute_rw(struct se_cmd *cmd) cmd->data_direction); } +static sense_reason_t compare_and_write_post(struct se_cmd *cmd) +{ + struct se_device *dev = cmd->se_dev; + + cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST; + /* + * Unlock ->caw_sem originally obtained during sbc_compare_and_write() + * before the original READ I/O submission. + */ + up(&dev->caw_sem); + + return TCM_NO_SENSE; +} + +static sense_reason_t compare_and_write_callback(struct se_cmd *cmd) +{ + struct se_device *dev = cmd->se_dev; + struct scatterlist *write_sg = NULL, *sg; + unsigned char *buf, *addr; + struct sg_mapping_iter m; + unsigned int offset = 0, len; + unsigned int nlbas = cmd->t_task_nolb; + unsigned int block_size = dev->dev_attrib.block_size; + unsigned int compare_len = (nlbas * block_size); + sense_reason_t ret = TCM_NO_SENSE; + int rc, i; + + buf = kzalloc(cmd->data_length, GFP_KERNEL); + if (!buf) { + pr_err("Unable to allocate compare_and_write buf\n"); + return TCM_OUT_OF_RESOURCES; + } + + write_sg = kzalloc(sizeof(struct scatterlist) * cmd->t_data_nents, + GFP_KERNEL); + if (!write_sg) { + pr_err("Unable to allocate compare_and_write sg\n"); + ret = TCM_OUT_OF_RESOURCES; + goto out; + } + /* + * Setup verify and write data payloads from total NumberLBAs. + */ + rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf, + cmd->data_length); + if (!rc) { + pr_err("sg_copy_to_buffer() failed for compare_and_write\n"); + ret = TCM_OUT_OF_RESOURCES; + goto out; + } + /* + * Compare against SCSI READ payload against verify payload + */ + for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) { + addr = (unsigned char *)kmap_atomic(sg_page(sg)); + if (!addr) { + ret = TCM_OUT_OF_RESOURCES; + goto out; + } + + len = min(sg->length, compare_len); + + if (memcmp(addr, buf + offset, len)) { + pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n", + addr, buf + offset); + kunmap_atomic(addr); + goto miscompare; + } + kunmap_atomic(addr); + + offset += len; + compare_len -= len; + if (!compare_len) + break; + } + + i = 0; + len = cmd->t_task_nolb * block_size; + sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG); + /* + * Currently assumes NoLB=1 and SGLs are PAGE_SIZE.. + */ + while (len) { + sg_miter_next(&m); + + if (block_size < PAGE_SIZE) { + sg_set_page(&write_sg[i], m.page, block_size, + block_size); + } else { + sg_miter_next(&m); + sg_set_page(&write_sg[i], m.page, block_size, + 0); + } + len -= block_size; + i++; + } + sg_miter_stop(&m); + /* + * Save the original SGL + nents values before updating to new + * assignments, to be released in transport_free_pages() -> + * transport_reset_sgl_orig() + */ + cmd->t_data_sg_orig = cmd->t_data_sg; + cmd->t_data_sg = write_sg; + cmd->t_data_nents_orig = cmd->t_data_nents; + cmd->t_data_nents = 1; + + cmd->sam_task_attr = MSG_HEAD_TAG; + cmd->transport_complete_callback = compare_and_write_post; + /* + * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler + * for submitting the adjusted SGL to write instance user-data. + */ + cmd->execute_cmd = sbc_execute_rw; + + spin_lock_irq(&cmd->t_state_lock); + cmd->t_state = TRANSPORT_PROCESSING; + cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT; + spin_unlock_irq(&cmd->t_state_lock); + + __target_execute_cmd(cmd); + + kfree(buf); + return ret; + +miscompare: + pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n", + dev->transport->name); + ret = TCM_MISCOMPARE_VERIFY; +out: + /* + * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in + * sbc_compare_and_write() before the original READ I/O submission. + */ + up(&dev->caw_sem); + kfree(write_sg); + kfree(buf); + return ret; +} + +static sense_reason_t +sbc_compare_and_write(struct se_cmd *cmd) +{ + struct se_device *dev = cmd->se_dev; + sense_reason_t ret; + int rc; + /* + * Submit the READ first for COMPARE_AND_WRITE to perform the + * comparision using SGLs at cmd->t_bidi_data_sg.. + */ + rc = down_interruptible(&dev->caw_sem); + if ((rc != 0) || signal_pending(current)) { + cmd->transport_complete_callback = NULL; + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + } + + ret = cmd->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents, + DMA_FROM_DEVICE); + if (ret) { + cmd->transport_complete_callback = NULL; + up(&dev->caw_sem); + return ret; + } + /* + * Unlock of dev->caw_sem to occur in compare_and_write_callback() + * upon MISCOMPARE, or in compare_and_write_done() upon completion + * of WRITE instance user-data. + */ + return TCM_NO_SENSE; +} + sense_reason_t sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) { @@ -481,6 +653,28 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) } break; } + case COMPARE_AND_WRITE: + sectors = cdb[13]; + /* + * Currently enforce COMPARE_AND_WRITE for a single sector + */ + if (sectors > 1) { + pr_err("COMPARE_AND_WRITE contains NoLB: %u greater" + " than 1\n", sectors); + return TCM_INVALID_CDB_FIELD; + } + /* + * Double size because we have two buffers, note that + * zero is not an error.. + */ + size = 2 * sbc_get_size(cmd, sectors); + cmd->t_task_lba = get_unaligned_be64(&cdb[2]); + cmd->t_task_nolb = sectors; + cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE; + cmd->execute_rw = ops->execute_rw; + cmd->execute_cmd = sbc_compare_and_write; + cmd->transport_complete_callback = compare_and_write_callback; + break; case READ_CAPACITY: size = READ_CAP_LEN; cmd->execute_cmd = sbc_emulate_readcapacity; @@ -620,7 +814,8 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) return TCM_ADDRESS_OUT_OF_RANGE; } - size = sbc_get_size(cmd, sectors); + if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) + size = sbc_get_size(cmd, sectors); } return target_cmd_size_check(cmd, size); diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index 61a4dc890701..b5d0c2496c7e 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -672,6 +672,7 @@ struct se_device { spinlock_t se_port_lock; spinlock_t se_tmr_lock; spinlock_t qf_cmd_lock; + struct semaphore caw_sem; /* Used for legacy SPC-2 reservationsa */ struct se_node_acl *dev_reserved_node_acl; /* Used for ALUA Logical Unit Group membership */ |
