linux/include/target/target_core_backend.h
Nicholas Bellinger 29a05deebf target: Convert se_node_acl->device_list[] to RCU hlist
This patch converts se_node_acl->device_list[] table for mappedluns
to modern RCU hlist_head usage in order to support an arbitrary number
of node_acl lun mappings.

It converts transport_lookup_*_lun() fast-path code to use RCU read path
primitives when looking up se_dev_entry.  It adds a new hlist_head at
se_node_acl->lun_entry_hlist for this purpose.

For transport_lookup_cmd_lun() code, it works with existing per-cpu
se_lun->lun_ref when associating se_cmd with se_lun + se_device.
Also, go ahead and update core_create_device_list_for_node() +
core_free_device_list_for_node() to use ->lun_entry_hlist.

It also converts se_dev_entry->pr_ref_count access to use modern
struct kref counting, and updates core_disable_device_list_for_node()
to kref_put() and block on se_deve->pr_comp waiting for outstanding PR
special-case PR references to drop, then invoke kfree_rcu() to wait
for the RCU grace period to complete before releasing memory.

So now that se_node_acl->lun_entry_hlist fast path access uses RCU
protected pointers, go ahead and convert remaining non-fast path
RCU updater code using ->lun_entry_lock to struct mutex to allow
callers to block while walking se_node_acl->lun_entry_hlist.

Finally drop the left-over core_clear_initiator_node_from_tpg() that
originally cleared lun_access during se_node_acl shutdown, as post
RCU conversion it now becomes duplicated logic.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-06-01 00:23:46 -07:00

141 lines
5.8 KiB
C

#ifndef TARGET_CORE_BACKEND_H
#define TARGET_CORE_BACKEND_H
#define TRANSPORT_FLAG_PASSTHROUGH 1
struct target_backend_cits {
struct config_item_type tb_dev_cit;
struct config_item_type tb_dev_attrib_cit;
struct config_item_type tb_dev_pr_cit;
struct config_item_type tb_dev_wwn_cit;
struct config_item_type tb_dev_alua_tg_pt_gps_cit;
struct config_item_type tb_dev_stat_cit;
};
struct se_subsystem_api {
struct list_head sub_api_list;
char name[16];
char inquiry_prod[16];
char inquiry_rev[4];
struct module *owner;
u8 transport_flags;
int (*attach_hba)(struct se_hba *, u32);
void (*detach_hba)(struct se_hba *);
int (*pmode_enable_hba)(struct se_hba *, unsigned long);
struct se_device *(*alloc_device)(struct se_hba *, const char *);
int (*configure_device)(struct se_device *);
void (*free_device)(struct se_device *device);
ssize_t (*set_configfs_dev_params)(struct se_device *,
const char *, ssize_t);
ssize_t (*show_configfs_dev_params)(struct se_device *, char *);
void (*transport_complete)(struct se_cmd *cmd,
struct scatterlist *,
unsigned char *);
sense_reason_t (*parse_cdb)(struct se_cmd *cmd);
u32 (*get_device_type)(struct se_device *);
sector_t (*get_blocks)(struct se_device *);
sector_t (*get_alignment_offset_lbas)(struct se_device *);
/* lbppbe = logical blocks per physical block exponent. see SBC-3 */
unsigned int (*get_lbppbe)(struct se_device *);
unsigned int (*get_io_min)(struct se_device *);
unsigned int (*get_io_opt)(struct se_device *);
unsigned char *(*get_sense_buffer)(struct se_cmd *);
bool (*get_write_cache)(struct se_device *);
int (*init_prot)(struct se_device *);
int (*format_prot)(struct se_device *);
void (*free_prot)(struct se_device *);
struct target_backend_cits tb_cits;
};
struct sbc_ops {
sense_reason_t (*execute_rw)(struct se_cmd *cmd, struct scatterlist *,
u32, enum dma_data_direction);
sense_reason_t (*execute_sync_cache)(struct se_cmd *cmd);
sense_reason_t (*execute_write_same)(struct se_cmd *cmd);
sense_reason_t (*execute_write_same_unmap)(struct se_cmd *cmd);
sense_reason_t (*execute_unmap)(struct se_cmd *cmd);
};
int transport_subsystem_register(struct se_subsystem_api *);
void transport_subsystem_release(struct se_subsystem_api *);
void target_complete_cmd(struct se_cmd *, u8);
void target_complete_cmd_with_length(struct se_cmd *, u8, int);
sense_reason_t spc_parse_cdb(struct se_cmd *cmd, unsigned int *size);
sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd);
sense_reason_t spc_emulate_inquiry_std(struct se_cmd *, unsigned char *);
sense_reason_t spc_emulate_evpd_83(struct se_cmd *, unsigned char *);
sense_reason_t sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops);
u32 sbc_get_device_rev(struct se_device *dev);
u32 sbc_get_device_type(struct se_device *dev);
sector_t sbc_get_write_same_sectors(struct se_cmd *cmd);
sense_reason_t sbc_execute_unmap(struct se_cmd *cmd,
sense_reason_t (*do_unmap_fn)(struct se_cmd *cmd, void *priv,
sector_t lba, sector_t nolb),
void *priv);
void sbc_dif_generate(struct se_cmd *);
sense_reason_t sbc_dif_verify(struct se_cmd *, sector_t, unsigned int,
unsigned int, struct scatterlist *, int);
void sbc_dif_copy_prot(struct se_cmd *, unsigned int, bool,
struct scatterlist *, int);
void transport_set_vpd_proto_id(struct t10_vpd *, unsigned char *);
int transport_set_vpd_assoc(struct t10_vpd *, unsigned char *);
int transport_set_vpd_ident_type(struct t10_vpd *, unsigned char *);
int transport_set_vpd_ident(struct t10_vpd *, unsigned char *);
/* core helpers also used by command snooping in pscsi */
void *transport_kmap_data_sg(struct se_cmd *);
void transport_kunmap_data_sg(struct se_cmd *);
/* core helpers also used by xcopy during internal command setup */
int target_alloc_sgl(struct scatterlist **, unsigned int *, u32, bool);
sense_reason_t transport_generic_map_mem_to_cmd(struct se_cmd *,
struct scatterlist *, u32, struct scatterlist *, u32);
bool target_lun_is_rdonly(struct se_cmd *);
/* From target_core_configfs.c to setup default backend config_item_types */
void target_core_setup_sub_cits(struct se_subsystem_api *);
/* attribute helpers from target_core_device.c for backend drivers */
bool se_dev_check_wce(struct se_device *);
int se_dev_set_max_unmap_lba_count(struct se_device *, u32);
int se_dev_set_max_unmap_block_desc_count(struct se_device *, u32);
int se_dev_set_unmap_granularity(struct se_device *, u32);
int se_dev_set_unmap_granularity_alignment(struct se_device *, u32);
int se_dev_set_max_write_same_len(struct se_device *, u32);
int se_dev_set_emulate_model_alias(struct se_device *, int);
int se_dev_set_emulate_dpo(struct se_device *, int);
int se_dev_set_emulate_fua_write(struct se_device *, int);
int se_dev_set_emulate_fua_read(struct se_device *, int);
int se_dev_set_emulate_write_cache(struct se_device *, int);
int se_dev_set_emulate_ua_intlck_ctrl(struct se_device *, int);
int se_dev_set_emulate_tas(struct se_device *, int);
int se_dev_set_emulate_tpu(struct se_device *, int);
int se_dev_set_emulate_tpws(struct se_device *, int);
int se_dev_set_emulate_caw(struct se_device *, int);
int se_dev_set_emulate_3pc(struct se_device *, int);
int se_dev_set_pi_prot_type(struct se_device *, int);
int se_dev_set_pi_prot_format(struct se_device *, int);
int se_dev_set_enforce_pr_isids(struct se_device *, int);
int se_dev_set_force_pr_aptpl(struct se_device *, int);
int se_dev_set_is_nonrot(struct se_device *, int);
int se_dev_set_emulate_rest_reord(struct se_device *dev, int);
int se_dev_set_queue_depth(struct se_device *, u32);
int se_dev_set_max_sectors(struct se_device *, u32);
int se_dev_set_optimal_sectors(struct se_device *, u32);
int se_dev_set_block_size(struct se_device *, u32);
sense_reason_t passthrough_parse_cdb(struct se_cmd *cmd,
sense_reason_t (*exec_cmd)(struct se_cmd *cmd));
#endif /* TARGET_CORE_BACKEND_H */