linux/include/target/target_core_fabric.h
Nicholas Bellinger dff0ca9ea7 target: Fix ordered task target_setup_cmd_from_cdb exception hang
If a command with a Simple task attribute is failed due to a Unit
Attention, then a subsequent command with an Ordered task attribute
will hang forever.  The reason for this is that the Unit Attention
status is checked for in target_setup_cmd_from_cdb, before the call
to target_execute_cmd, which calls target_handle_task_attr, which
in turn increments dev->simple_cmds.

However, transport_generic_request_failure still calls
transport_complete_task_attr, which will decrement dev->simple_cmds.
In this case, simple_cmds is now -1.  So when a command with the
Ordered task attribute is sent, target_handle_task_attr sees that
dev->simple_cmds is not 0, so it decides it can't execute the
command until all the (nonexistent) Simple commands have completed.

Reported-by: Michael Cyr <mikecyr@linux.vnet.ibm.com>
Tested-by: Michael Cyr <mikecyr@linux.vnet.ibm.com>
Reported-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 4.4+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2016-07-20 00:58:38 -07:00

212 lines
8.5 KiB
C

#ifndef TARGET_CORE_FABRIC_H
#define TARGET_CORE_FABRIC_H
struct target_core_fabric_ops {
struct module *module;
const char *name;
size_t node_acl_size;
/*
* Limits number of scatterlist entries per SCF_SCSI_DATA_CDB payload.
* Setting this value tells target-core to enforce this limit, and
* report as INQUIRY EVPD=b0 MAXIMUM TRANSFER LENGTH.
*
* target-core will currently reset se_cmd->data_length to this
* maximum size, and set UNDERFLOW residual count if length exceeds
* this limit.
*
* XXX: Not all initiator hosts honor this block-limit EVPD
* XXX: Currently assumes single PAGE_SIZE per scatterlist entry
*/
u32 max_data_sg_nents;
char *(*get_fabric_name)(void);
char *(*tpg_get_wwn)(struct se_portal_group *);
u16 (*tpg_get_tag)(struct se_portal_group *);
u32 (*tpg_get_default_depth)(struct se_portal_group *);
int (*tpg_check_demo_mode)(struct se_portal_group *);
int (*tpg_check_demo_mode_cache)(struct se_portal_group *);
int (*tpg_check_demo_mode_write_protect)(struct se_portal_group *);
int (*tpg_check_prod_mode_write_protect)(struct se_portal_group *);
/*
* Optionally used by fabrics to allow demo-mode login, but not
* expose any TPG LUNs, and return 'not connected' in standard
* inquiry response
*/
int (*tpg_check_demo_mode_login_only)(struct se_portal_group *);
/*
* Optionally used as a configfs tunable to determine when
* target-core should signal the PROTECT=1 feature bit for
* backends that don't support T10-PI, so that either fabric
* HW offload or target-core emulation performs the associated
* WRITE_STRIP and READ_INSERT operations.
*/
int (*tpg_check_prot_fabric_only)(struct se_portal_group *);
u32 (*tpg_get_inst_index)(struct se_portal_group *);
/*
* Optional to release struct se_cmd and fabric dependent allocated
* I/O descriptor in transport_cmd_check_stop().
*
* Returning 1 will signal a descriptor has been released.
* Returning 0 will signal a descriptor has not been released.
*/
int (*check_stop_free)(struct se_cmd *);
void (*release_cmd)(struct se_cmd *);
void (*close_session)(struct se_session *);
u32 (*sess_get_index)(struct se_session *);
/*
* Used only for SCSI fabrics that contain multi-value TransportIDs
* (like iSCSI). All other SCSI fabrics should set this to NULL.
*/
u32 (*sess_get_initiator_sid)(struct se_session *,
unsigned char *, u32);
int (*write_pending)(struct se_cmd *);
int (*write_pending_status)(struct se_cmd *);
void (*set_default_node_attributes)(struct se_node_acl *);
int (*get_cmd_state)(struct se_cmd *);
int (*queue_data_in)(struct se_cmd *);
int (*queue_status)(struct se_cmd *);
void (*queue_tm_rsp)(struct se_cmd *);
void (*aborted_task)(struct se_cmd *);
/*
* fabric module calls for target_core_fabric_configfs.c
*/
struct se_wwn *(*fabric_make_wwn)(struct target_fabric_configfs *,
struct config_group *, const char *);
void (*fabric_drop_wwn)(struct se_wwn *);
void (*add_wwn_groups)(struct se_wwn *);
struct se_portal_group *(*fabric_make_tpg)(struct se_wwn *,
struct config_group *, const char *);
void (*fabric_drop_tpg)(struct se_portal_group *);
int (*fabric_post_link)(struct se_portal_group *,
struct se_lun *);
void (*fabric_pre_unlink)(struct se_portal_group *,
struct se_lun *);
struct se_tpg_np *(*fabric_make_np)(struct se_portal_group *,
struct config_group *, const char *);
void (*fabric_drop_np)(struct se_tpg_np *);
int (*fabric_init_nodeacl)(struct se_node_acl *, const char *);
struct configfs_attribute **tfc_discovery_attrs;
struct configfs_attribute **tfc_wwn_attrs;
struct configfs_attribute **tfc_tpg_base_attrs;
struct configfs_attribute **tfc_tpg_np_base_attrs;
struct configfs_attribute **tfc_tpg_attrib_attrs;
struct configfs_attribute **tfc_tpg_auth_attrs;
struct configfs_attribute **tfc_tpg_param_attrs;
struct configfs_attribute **tfc_tpg_nacl_base_attrs;
struct configfs_attribute **tfc_tpg_nacl_attrib_attrs;
struct configfs_attribute **tfc_tpg_nacl_auth_attrs;
struct configfs_attribute **tfc_tpg_nacl_param_attrs;
};
int target_register_template(const struct target_core_fabric_ops *fo);
void target_unregister_template(const struct target_core_fabric_ops *fo);
int target_depend_item(struct config_item *item);
void target_undepend_item(struct config_item *item);
struct se_session *target_alloc_session(struct se_portal_group *,
unsigned int, unsigned int, enum target_prot_op prot_op,
const char *, void *,
int (*callback)(struct se_portal_group *,
struct se_session *, void *));
struct se_session *transport_init_session(enum target_prot_op);
int transport_alloc_session_tags(struct se_session *, unsigned int,
unsigned int);
struct se_session *transport_init_session_tags(unsigned int, unsigned int,
enum target_prot_op);
void __transport_register_session(struct se_portal_group *,
struct se_node_acl *, struct se_session *, void *);
void transport_register_session(struct se_portal_group *,
struct se_node_acl *, struct se_session *, void *);
ssize_t target_show_dynamic_sessions(struct se_portal_group *, char *);
void transport_free_session(struct se_session *);
void target_put_nacl(struct se_node_acl *);
void transport_deregister_session_configfs(struct se_session *);
void transport_deregister_session(struct se_session *);
void transport_init_se_cmd(struct se_cmd *,
const struct target_core_fabric_ops *,
struct se_session *, u32, int, int, unsigned char *);
sense_reason_t transport_lookup_cmd_lun(struct se_cmd *, u64);
sense_reason_t target_setup_cmd_from_cdb(struct se_cmd *, unsigned char *);
int target_submit_cmd_map_sgls(struct se_cmd *, struct se_session *,
unsigned char *, unsigned char *, u64, u32, int, int, int,
struct scatterlist *, u32, struct scatterlist *, u32,
struct scatterlist *, u32);
int target_submit_cmd(struct se_cmd *, struct se_session *, unsigned char *,
unsigned char *, u64, u32, int, int, int);
int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
unsigned char *sense, u64 unpacked_lun,
void *fabric_tmr_ptr, unsigned char tm_type,
gfp_t, u64, int);
int transport_handle_cdb_direct(struct se_cmd *);
sense_reason_t transport_generic_new_cmd(struct se_cmd *);
void target_execute_cmd(struct se_cmd *cmd);
int transport_generic_free_cmd(struct se_cmd *, int);
bool transport_wait_for_tasks(struct se_cmd *);
int transport_check_aborted_status(struct se_cmd *, int);
int transport_send_check_condition_and_sense(struct se_cmd *,
sense_reason_t, int);
int target_get_sess_cmd(struct se_cmd *, bool);
int target_put_sess_cmd(struct se_cmd *);
void target_sess_cmd_list_set_waiting(struct se_session *);
void target_wait_for_sess_cmds(struct se_session *);
int core_alua_check_nonop_delay(struct se_cmd *);
int core_tmr_alloc_req(struct se_cmd *, void *, u8, gfp_t);
void core_tmr_release_req(struct se_tmr_req *);
int transport_generic_handle_tmr(struct se_cmd *);
void transport_generic_request_failure(struct se_cmd *, sense_reason_t);
int transport_lookup_tmr_lun(struct se_cmd *, u64);
void core_allocate_nexus_loss_ua(struct se_node_acl *acl);
struct se_node_acl *core_tpg_get_initiator_node_acl(struct se_portal_group *tpg,
unsigned char *);
bool target_tpg_has_node_acl(struct se_portal_group *tpg,
const char *);
struct se_node_acl *core_tpg_check_initiator_node_acl(struct se_portal_group *,
unsigned char *);
int core_tpg_set_initiator_node_queue_depth(struct se_node_acl *, u32);
int core_tpg_set_initiator_node_tag(struct se_portal_group *,
struct se_node_acl *, const char *);
int core_tpg_register(struct se_wwn *, struct se_portal_group *, int);
int core_tpg_deregister(struct se_portal_group *);
int target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents,
u32 length, bool zero_page, bool chainable);
void target_free_sgl(struct scatterlist *sgl, int nents);
/*
* The LIO target core uses DMA_TO_DEVICE to mean that data is going
* to the target (eg handling a WRITE) and DMA_FROM_DEVICE to mean
* that data is coming from the target (eg handling a READ). However,
* this is just the opposite of what we have to tell the DMA mapping
* layer -- eg when handling a READ, the HBA will have to DMA the data
* out of memory so it can send it to the initiator, which means we
* need to use DMA_TO_DEVICE when we map the data.
*/
static inline enum dma_data_direction
target_reverse_dma_direction(struct se_cmd *se_cmd)
{
if (se_cmd->se_cmd_flags & SCF_BIDI)
return DMA_BIDIRECTIONAL;
switch (se_cmd->data_direction) {
case DMA_TO_DEVICE:
return DMA_FROM_DEVICE;
case DMA_FROM_DEVICE:
return DMA_TO_DEVICE;
case DMA_NONE:
default:
return DMA_NONE;
}
}
#endif /* TARGET_CORE_FABRICH */