linux/include/target/target_core_backend.h
Nicholas Bellinger d0c8b259f8 target/iblock: Use backend REQ_FLUSH hint for WriteCacheEnabled status
This patch allows IBLOCK to check block hints in request_queue->flush_flags
when reporting current backend device WriteCacheEnabled status to a remote
SCSI initiator port.

This is done via a se_subsystem_api->get_write_cache() call instead of a
backend se_device creation time flag, as we expect REQ_FLUSH bits to possibly
change from an underlying blk_queue_flush() by the SCSI disk driver, or
internal raw struct block_device driver usage.

Also go ahead and update iblock_execute_rw() bio I/O path code to use
REQ_FLUSH + REQ_FUA hints when determining WRITE_FUA usage, and make SPC
emulation code use a spc_check_dev_wce() helper to handle both types of
cases for virtual backend subsystem drivers.

(asias: Drop unnecessary comparsion operators)

Reported-by: majianpeng <majianpeng@gmail.com>
Cc: majianpeng <majianpeng@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2013-02-13 11:27:51 -08:00

76 lines
2.6 KiB
C

#ifndef TARGET_CORE_BACKEND_H
#define TARGET_CORE_BACKEND_H
#define TRANSPORT_PLUGIN_PHBA_PDEV 1
#define TRANSPORT_PLUGIN_VHBA_PDEV 2
#define TRANSPORT_PLUGIN_VHBA_VDEV 3
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_type;
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 *);
unsigned char *(*get_sense_buffer)(struct se_cmd *);
bool (*get_write_cache)(struct se_device *);
};
struct sbc_ops {
sense_reason_t (*execute_rw)(struct se_cmd *cmd);
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);
sense_reason_t spc_parse_cdb(struct se_cmd *cmd, unsigned int *size);
sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd);
sector_t spc_get_write_same_sectors(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);
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 *);
void array_free(void *array, int n);
#endif /* TARGET_CORE_BACKEND_H */