diff options
author | Christoph Hellwig <hch@lst.de> | 2012-11-06 12:24:09 -0800 |
---|---|---|
committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2012-11-06 20:55:46 -0800 |
commit | de103c93aff0bed0ae984274e5dc8b95899badab (patch) | |
tree | 7db9bba755fa95772052e8d31285a38ba48f1a84 /drivers/target/target_core_transport.c | |
parent | fecae40abb1ae9218bdbaa8b8e30bfb5ae43f522 (diff) | |
download | linux-de103c93aff0bed0ae984274e5dc8b95899badab.tar.bz2 |
target: pass sense_reason as a return value
Pass the sense reason as an explicit return value from the I/O submission
path instead of storing it in struct se_cmd and using negative return
values. This cleans up a lot of the code pathes, and with the sparse
annotations for the new sense_reason_t type allows for much better
error checking.
(nab: Convert spc_emulate_modesense + spc_emulate_modeselect to use
sense_reason_t with Roland's MODE SELECT changes)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/target_core_transport.c')
-rw-r--r-- | drivers/target/target_core_transport.c | 252 |
1 files changed, 99 insertions, 153 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index c4c931b525d2..98044bf1da08 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -557,7 +557,8 @@ static void target_complete_failure_work(struct work_struct *work) { struct se_cmd *cmd = container_of(work, struct se_cmd, work); - transport_generic_request_failure(cmd); + transport_generic_request_failure(cmd, + TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE); } /* @@ -625,7 +626,6 @@ void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status) complete(&cmd->t_transport_stop_comp); return; } else if (cmd->transport_state & CMD_T_FAILED) { - cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; INIT_WORK(&cmd->work, target_complete_failure_work); } else { INIT_WORK(&cmd->work, target_complete_ok_work); @@ -976,7 +976,8 @@ transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83) } EXPORT_SYMBOL(transport_set_vpd_ident); -int target_cmd_size_check(struct se_cmd *cmd, unsigned int size) +sense_reason_t +target_cmd_size_check(struct se_cmd *cmd, unsigned int size) { struct se_device *dev = cmd->se_dev; @@ -991,7 +992,7 @@ int target_cmd_size_check(struct se_cmd *cmd, unsigned int size) if (cmd->data_direction == DMA_TO_DEVICE) { pr_err("Rejecting underflow/overflow" " WRITE data\n"); - goto out_invalid_cdb_field; + return TCM_INVALID_CDB_FIELD; } /* * Reject READ_* or WRITE_* with overflow/underflow for @@ -1002,7 +1003,7 @@ int target_cmd_size_check(struct se_cmd *cmd, unsigned int size) " CDB on non 512-byte sector setup subsystem" " plugin: %s\n", dev->transport->name); /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */ - goto out_invalid_cdb_field; + return TCM_INVALID_CDB_FIELD; } /* * For the overflow case keep the existing fabric provided @@ -1022,10 +1023,6 @@ int target_cmd_size_check(struct se_cmd *cmd, unsigned int size) return 0; -out_invalid_cdb_field: - cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION; - cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD; - return -EINVAL; } /* @@ -1065,7 +1062,8 @@ void transport_init_se_cmd( } EXPORT_SYMBOL(transport_init_se_cmd); -static int transport_check_alloc_task_attr(struct se_cmd *cmd) +static sense_reason_t +transport_check_alloc_task_attr(struct se_cmd *cmd) { struct se_device *dev = cmd->se_dev; @@ -1079,7 +1077,7 @@ static int transport_check_alloc_task_attr(struct se_cmd *cmd) if (cmd->sam_task_attr == MSG_ACA_TAG) { pr_debug("SAM Task Attribute ACA" " emulation is not supported\n"); - return -EINVAL; + return TCM_INVALID_CDB_FIELD; } /* * Used to determine when ORDERED commands should go from @@ -1093,17 +1091,12 @@ static int transport_check_alloc_task_attr(struct se_cmd *cmd) return 0; } -/* target_setup_cmd_from_cdb(): - * - * Called from fabric RX Thread. - */ -int target_setup_cmd_from_cdb( - struct se_cmd *cmd, - unsigned char *cdb) +sense_reason_t +target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb) { struct se_device *dev = cmd->se_dev; unsigned long flags; - int ret; + sense_reason_t ret; /* * Ensure that the received CDB is less than the max (252 + 8) bytes @@ -1113,9 +1106,7 @@ int target_setup_cmd_from_cdb( pr_err("Received SCSI CDB with command_size: %d that" " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n", scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE); - cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION; - cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD; - return -EINVAL; + return TCM_INVALID_CDB_FIELD; } /* * If the received CDB is larger than TCM_MAX_COMMAND_SIZE, @@ -1130,10 +1121,7 @@ int target_setup_cmd_from_cdb( " %u > sizeof(cmd->__t_task_cdb): %lu ops\n", scsi_command_size(cdb), (unsigned long)sizeof(cmd->__t_task_cdb)); - cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION; - cmd->scsi_sense_reason = - TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; - return -ENOMEM; + return TCM_OUT_OF_RESOURCES; } } else cmd->t_task_cdb = &cmd->__t_task_cdb[0]; @@ -1145,50 +1133,30 @@ int target_setup_cmd_from_cdb( /* * Check for an existing UNIT ATTENTION condition */ - if (core_scsi3_ua_check(cmd, cdb) < 0) { - cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION; - cmd->scsi_sense_reason = TCM_CHECK_CONDITION_UNIT_ATTENTION; - return -EINVAL; - } + ret = target_scsi3_ua_check(cmd); + if (ret) + return ret; ret = target_alua_state_check(cmd); - if (ret) { - cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION; - if (ret > 0) - cmd->scsi_sense_reason = TCM_CHECK_CONDITION_NOT_READY; - else - cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD; - return -EINVAL; - } + if (ret) + return ret; - /* - * Check status for SPC-3 Persistent Reservations - */ ret = target_check_reservation(cmd); - if (ret) { - cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION; - cmd->se_cmd_flags |= SCF_SCSI_RESERVATION_CONFLICT; - cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT; - cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT; + if (ret) return ret; - } ret = dev->transport->parse_cdb(cmd); - if (ret < 0) + if (ret) + return ret; + + ret = transport_check_alloc_task_attr(cmd); + if (ret) return ret; spin_lock_irqsave(&cmd->t_state_lock, flags); cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE; spin_unlock_irqrestore(&cmd->t_state_lock, flags); - /* - * Check for SAM Task Attribute Emulation - */ - if (transport_check_alloc_task_attr(cmd) < 0) { - cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION; - cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD; - return -EINVAL; - } spin_lock(&cmd->se_lun->lun_sep_lock); if (cmd->se_lun->lun_sep) cmd->se_lun->lun_sep->sep_stats.cmd_pdus++; @@ -1204,7 +1172,7 @@ EXPORT_SYMBOL(target_setup_cmd_from_cdb); int transport_handle_cdb_direct( struct se_cmd *cmd) { - int ret; + sense_reason_t ret; if (!cmd->se_lun) { dump_stack(); @@ -1234,13 +1202,41 @@ int transport_handle_cdb_direct( * and call transport_generic_request_failure() if necessary.. */ ret = transport_generic_new_cmd(cmd); - if (ret < 0) - transport_generic_request_failure(cmd); - + if (ret) + transport_generic_request_failure(cmd, ret); return 0; } EXPORT_SYMBOL(transport_handle_cdb_direct); +static sense_reason_t +transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl, + u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count) +{ + if (!sgl || !sgl_count) + return 0; + + /* + * Reject SCSI data overflow with map_mem_to_cmd() as incoming + * scatterlists already have been set to follow what the fabric + * passes for the original expected data transfer length. + */ + if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) { + pr_warn("Rejecting SCSI DATA overflow for fabric using" + " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n"); + return TCM_INVALID_CDB_FIELD; + } + + cmd->t_data_sg = sgl; + cmd->t_data_nents = sgl_count; + + if (sgl_bidi && sgl_bidi_count) { + cmd->t_bidi_data_sg = sgl_bidi; + cmd->t_bidi_data_nents = sgl_bidi_count; + } + cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC; + return 0; +} + /* * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized * se_cmd + use pre-allocated SGL memory. @@ -1273,7 +1269,8 @@ int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess struct scatterlist *sgl_bidi, u32 sgl_bidi_count) { struct se_portal_group *se_tpg; - int rc; + sense_reason_t rc; + int ret; se_tpg = se_sess->se_tpg; BUG_ON(!se_tpg); @@ -1294,9 +1291,9 @@ int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess * for fabrics using TARGET_SCF_ACK_KREF that expect a second * kref_put() to happen during fabric packet acknowledgement. */ - rc = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF)); - if (rc) - return rc; + ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF)); + if (ret) + return ret; /* * Signal bidirectional data payloads to target-core */ @@ -1305,16 +1302,16 @@ int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess /* * Locate se_lun pointer and attach it to struct se_cmd */ - if (transport_lookup_cmd_lun(se_cmd, unpacked_lun) < 0) { - transport_send_check_condition_and_sense(se_cmd, - se_cmd->scsi_sense_reason, 0); + rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun); + if (rc) { + transport_send_check_condition_and_sense(se_cmd, rc, 0); target_put_sess_cmd(se_sess, se_cmd); return 0; } rc = target_setup_cmd_from_cdb(se_cmd, cdb); if (rc != 0) { - transport_generic_request_failure(se_cmd); + transport_generic_request_failure(se_cmd, rc); return 0; } /* @@ -1349,7 +1346,7 @@ int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count, sgl_bidi, sgl_bidi_count); if (rc != 0) { - transport_generic_request_failure(se_cmd); + transport_generic_request_failure(se_cmd, rc); return 0; } } @@ -1495,16 +1492,17 @@ bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags) /* * Handle SAM-esque emulation for generic transport request failures. */ -void transport_generic_request_failure(struct se_cmd *cmd) +void transport_generic_request_failure(struct se_cmd *cmd, + sense_reason_t sense_reason) { int ret = 0; pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x" " CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd), cmd->t_task_cdb[0]); - pr_debug("-----[ i_state: %d t_state: %d scsi_sense_reason: %d\n", + pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n", cmd->se_tfo->get_cmd_state(cmd), - cmd->t_state, cmd->scsi_sense_reason); + cmd->t_state, sense_reason); pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n", (cmd->transport_state & CMD_T_ACTIVE) != 0, (cmd->transport_state & CMD_T_STOP) != 0, @@ -1515,7 +1513,7 @@ void transport_generic_request_failure(struct se_cmd *cmd) */ transport_complete_task_attr(cmd); - switch (cmd->scsi_sense_reason) { + switch (sense_reason) { case TCM_NON_EXISTENT_LUN: case TCM_UNSUPPORTED_SCSI_OPCODE: case TCM_INVALID_CDB_FIELD: @@ -1528,6 +1526,9 @@ void transport_generic_request_failure(struct se_cmd *cmd) case TCM_CHECK_CONDITION_UNIT_ATTENTION: case TCM_CHECK_CONDITION_NOT_READY: break; + case TCM_OUT_OF_RESOURCES: + sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + break; case TCM_RESERVATION_CONFLICT: /* * No SENSE Data payload for this case, set SCSI Status @@ -1555,13 +1556,12 @@ void transport_generic_request_failure(struct se_cmd *cmd) goto check_stop; default: pr_err("Unknown transport error for CDB 0x%02x: %d\n", - cmd->t_task_cdb[0], cmd->scsi_sense_reason); - cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE; + cmd->t_task_cdb[0], sense_reason); + sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE; break; } - ret = transport_send_check_condition_and_sense(cmd, - cmd->scsi_sense_reason, 0); + ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0); if (ret == -EAGAIN || ret == -ENOMEM) goto queue_full; @@ -1579,21 +1579,21 @@ EXPORT_SYMBOL(transport_generic_request_failure); static void __target_execute_cmd(struct se_cmd *cmd) { - int error = 0; + sense_reason_t ret; spin_lock_irq(&cmd->t_state_lock); cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT); spin_unlock_irq(&cmd->t_state_lock); - if (cmd->execute_cmd) - error = cmd->execute_cmd(cmd); - - if (error) { - spin_lock_irq(&cmd->t_state_lock); - cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT); - spin_unlock_irq(&cmd->t_state_lock); + if (cmd->execute_cmd) { + ret = cmd->execute_cmd(cmd); + if (ret) { + spin_lock_irq(&cmd->t_state_lock); + cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT); + spin_unlock_irq(&cmd->t_state_lock); - transport_generic_request_failure(cmd); + transport_generic_request_failure(cmd, ret); + } } } @@ -1987,53 +1987,6 @@ out_busy: spin_unlock_irqrestore(&cmd->t_state_lock, flags); } -/* - * transport_generic_map_mem_to_cmd - Use fabric-alloced pages instead of - * allocating in the core. - * @cmd: Associated se_cmd descriptor - * @mem: SGL style memory for TCM WRITE / READ - * @sg_mem_num: Number of SGL elements - * @mem_bidi_in: SGL style memory for TCM BIDI READ - * @sg_mem_bidi_num: Number of BIDI READ SGL elements - * - * Return: nonzero return cmd was rejected for -ENOMEM or inproper usage - * of parameters. - */ -int transport_generic_map_mem_to_cmd( - struct se_cmd *cmd, - struct scatterlist *sgl, - u32 sgl_count, - struct scatterlist *sgl_bidi, - u32 sgl_bidi_count) -{ - if (!sgl || !sgl_count) - return 0; - - /* - * Reject SCSI data overflow with map_mem_to_cmd() as incoming - * scatterlists already have been set to follow what the fabric - * passes for the original expected data transfer length. - */ - if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) { - pr_warn("Rejecting SCSI DATA overflow for fabric using" - " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n"); - cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION; - cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD; - return -EINVAL; - } - - cmd->t_data_sg = sgl; - cmd->t_data_nents = sgl_count; - - if (sgl_bidi && sgl_bidi_count) { - cmd->t_bidi_data_sg = sgl_bidi; - cmd->t_bidi_data_nents = sgl_bidi_count; - } - cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC; - return 0; -} -EXPORT_SYMBOL(transport_generic_map_mem_to_cmd); - void *transport_kmap_data_sg(struct se_cmd *cmd) { struct scatterlist *sg = cmd->t_data_sg; @@ -2054,10 +2007,8 @@ void *transport_kmap_data_sg(struct se_cmd *cmd) /* >1 page. use vmap */ pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL); - if (!pages) { - cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + if (!pages) return NULL; - } /* convert sg[] to pages[] */ for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) { @@ -2066,10 +2017,8 @@ void *transport_kmap_data_sg(struct se_cmd *cmd) cmd->t_data_vmap = vmap(pages, cmd->t_data_nents, VM_MAP, PAGE_KERNEL); kfree(pages); - if (!cmd->t_data_vmap) { - cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + if (!cmd->t_data_vmap) return NULL; - } return cmd->t_data_vmap + cmd->t_data_sg[0].offset; } @@ -2135,7 +2084,8 @@ out: * might not have the payload yet, so notify the fabric via a call to * ->write_pending instead. Otherwise place it on the execution queue. */ -int transport_generic_new_cmd(struct se_cmd *cmd) +sense_reason_t +transport_generic_new_cmd(struct se_cmd *cmd) { int ret = 0; @@ -2148,7 +2098,7 @@ int transport_generic_new_cmd(struct se_cmd *cmd) cmd->data_length) { ret = transport_generic_get_mem(cmd); if (ret < 0) - goto out_fail; + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; } atomic_inc(&cmd->t_fe_count); @@ -2174,14 +2124,11 @@ int transport_generic_new_cmd(struct se_cmd *cmd) if (ret == -EAGAIN || ret == -ENOMEM) goto queue_full; - if (ret < 0) - return ret; - return 1; + /* fabric drivers should only return -EAGAIN or -ENOMEM as error */ + WARN_ON(ret); + + return 0; -out_fail: - cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION; - cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; - return -EINVAL; queue_full: pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd); cmd->t_state = TRANSPORT_COMPLETE_QF_WP; @@ -2625,10 +2572,9 @@ static int transport_get_sense_codes( return 0; } -int transport_send_check_condition_and_sense( - struct se_cmd *cmd, - u8 reason, - int from_transport) +int +transport_send_check_condition_and_sense(struct se_cmd *cmd, + sense_reason_t reason, int from_transport) { unsigned char *buffer = cmd->sense_buffer; unsigned long flags; |