kernel-ark/include/linux/bsg.h
FUJITA Tomonori 97f46ae45c [SCSI] bsg: add release callback support
This patch adds release callback support, which is called when a bsg
device goes away. bsg_register_queue() takes a pointer to a callback
function. This feature is useful for stuff like sas_host that can't
use the release callback in struct device.

If a caller doesn't need bsg's release callback, it can call
bsg_register_queue() with NULL pointer (e.g. scsi devices can use
release callback in struct device so they don't need bsg's callback).

With this patch, bsg uses kref for refcounts on bsg devices instead of
get/put_device in fops->open/release. bsg calls put_device and the
caller's release callback (if it was registered) in kref_put's
release.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-04-22 15:16:32 -05:00

85 lines
2.7 KiB
C

#ifndef BSG_H
#define BSG_H
#define BSG_PROTOCOL_SCSI 0
#define BSG_SUB_PROTOCOL_SCSI_CMD 0
#define BSG_SUB_PROTOCOL_SCSI_TMF 1
#define BSG_SUB_PROTOCOL_SCSI_TRANSPORT 2
struct sg_io_v4 {
__s32 guard; /* [i] 'Q' to differentiate from v3 */
__u32 protocol; /* [i] 0 -> SCSI , .... */
__u32 subprotocol; /* [i] 0 -> SCSI command, 1 -> SCSI task
management function, .... */
__u32 request_len; /* [i] in bytes */
__u64 request; /* [i], [*i] {SCSI: cdb} */
__u64 request_tag; /* [i] {SCSI: task tag (only if flagged)} */
__u32 request_attr; /* [i] {SCSI: task attribute} */
__u32 request_priority; /* [i] {SCSI: task priority} */
__u32 request_extra; /* [i] {spare, for padding} */
__u32 max_response_len; /* [i] in bytes */
__u64 response; /* [i], [*o] {SCSI: (auto)sense data} */
/* "dout_": data out (to device); "din_": data in (from device) */
__u32 dout_iovec_count; /* [i] 0 -> "flat" dout transfer else
dout_xfer points to array of iovec */
__u32 dout_xfer_len; /* [i] bytes to be transferred to device */
__u32 din_iovec_count; /* [i] 0 -> "flat" din transfer */
__u32 din_xfer_len; /* [i] bytes to be transferred from device */
__u64 dout_xferp; /* [i], [*i] */
__u64 din_xferp; /* [i], [*o] */
__u32 timeout; /* [i] units: millisecond */
__u32 flags; /* [i] bit mask */
__u64 usr_ptr; /* [i->o] unused internally */
__u32 spare_in; /* [i] */
__u32 driver_status; /* [o] 0 -> ok */
__u32 transport_status; /* [o] 0 -> ok */
__u32 device_status; /* [o] {SCSI: command completion status} */
__u32 retry_delay; /* [o] {SCSI: status auxiliary information} */
__u32 info; /* [o] additional information */
__u32 duration; /* [o] time to complete, in milliseconds */
__u32 response_len; /* [o] bytes of response actually written */
__s32 din_resid; /* [o] din_xfer_len - actual_din_xfer_len */
__s32 dout_resid; /* [o] dout_xfer_len - actual_dout_xfer_len */
__u64 generated_tag; /* [o] {SCSI: transport generated task tag} */
__u32 spare_out; /* [o] */
__u32 padding;
};
#ifdef __KERNEL__
#if defined(CONFIG_BLK_DEV_BSG)
struct bsg_class_device {
struct device *class_dev;
struct device *parent;
int minor;
struct request_queue *queue;
struct kref ref;
void (*release)(struct device *);
};
extern int bsg_register_queue(struct request_queue *q,
struct device *parent, const char *name,
void (*release)(struct device *));
extern void bsg_unregister_queue(struct request_queue *);
#else
static inline int bsg_register_queue(struct request_queue *q,
struct device *parent, const char *name,
void (*release)(struct device *))
{
return 0;
}
static inline void bsg_unregister_queue(struct request_queue *q)
{
}
#endif
#endif /* __KERNEL__ */
#endif