linux/drivers/scsi/scsi_priv.h
Alan Stern fea6d607e1 [SCSI] scsi_pm: Fix bug in the SCSI power management handler
This patch (as1520) fixes a bug in the SCSI layer's power management
implementation.

LUN scanning can be carried out asynchronously in do_scan_async(), and
sd uses an asynchronous thread for the time-consuming parts of disk
probing in sd_probe_async().  Currently nothing coordinates these
async threads with system sleep transitions; they can and do attempt
to continue scanning/probing SCSI devices even after the host adapter
has been suspended.  As one might expect, the outcome is not ideal.

This is what the "prepare" stage of system suspend was created for.
After the prepare callback has been called for a host, target, or
device, drivers are not allowed to register any children underneath
them.  Currently the SCSI prepare callback is not implemented; this
patch rectifies that omission.

For SCSI hosts, the prepare routine calls scsi_complete_async_scans()
to wait until async scanning is finished.  It might be slightly more
efficient to wait only until the host in question has been scanned,
but there's currently no way to do that.  Besides, during a sleep
transition we will ultimately have to wait until all the host scanning
has finished anyway.

For SCSI devices, the prepare routine calls async_synchronize_full()
to wait until sd probing is finished.  The routine does nothing for
SCSI targets, because asynchronous target scanning is done only as
part of host scanning.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@kernel.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-02-18 08:54:19 -06:00

176 lines
5.8 KiB
C

#ifndef _SCSI_PRIV_H
#define _SCSI_PRIV_H
#include <linux/device.h>
struct request_queue;
struct request;
struct scsi_cmnd;
struct scsi_device;
struct scsi_target;
struct scsi_host_template;
struct Scsi_Host;
struct scsi_nl_hdr;
/*
* Scsi Error Handler Flags
*/
#define SCSI_EH_CANCEL_CMD 0x0001 /* Cancel this cmd */
#define SCSI_SENSE_VALID(scmd) \
(((scmd)->sense_buffer[0] & 0x70) == 0x70)
/* hosts.c */
extern int scsi_init_hosts(void);
extern void scsi_exit_hosts(void);
/* scsi.c */
extern int scsi_dispatch_cmd(struct scsi_cmnd *cmd);
extern int scsi_setup_command_freelist(struct Scsi_Host *shost);
extern void scsi_destroy_command_freelist(struct Scsi_Host *shost);
#ifdef CONFIG_SCSI_LOGGING
void scsi_log_send(struct scsi_cmnd *cmd);
void scsi_log_completion(struct scsi_cmnd *cmd, int disposition);
#else
static inline void scsi_log_send(struct scsi_cmnd *cmd)
{ };
static inline void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
{ };
#endif
/* scsi_devinfo.c */
/* list of keys for the lists */
enum {
SCSI_DEVINFO_GLOBAL = 0,
SCSI_DEVINFO_SPI,
};
extern int scsi_get_device_flags(struct scsi_device *sdev,
const unsigned char *vendor,
const unsigned char *model);
extern int scsi_get_device_flags_keyed(struct scsi_device *sdev,
const unsigned char *vendor,
const unsigned char *model, int key);
extern int scsi_dev_info_list_add_keyed(int compatible, char *vendor,
char *model, char *strflags,
int flags, int key);
extern int scsi_dev_info_list_del_keyed(char *vendor, char *model, int key);
extern int scsi_dev_info_add_list(int key, const char *name);
extern int scsi_dev_info_remove_list(int key);
extern int __init scsi_init_devinfo(void);
extern void scsi_exit_devinfo(void);
/* scsi_error.c */
extern enum blk_eh_timer_return scsi_times_out(struct request *req);
extern int scsi_error_handler(void *host);
extern int scsi_decide_disposition(struct scsi_cmnd *cmd);
extern void scsi_eh_wakeup(struct Scsi_Host *shost);
extern int scsi_eh_scmd_add(struct scsi_cmnd *, int);
void scsi_eh_ready_devs(struct Scsi_Host *shost,
struct list_head *work_q,
struct list_head *done_q);
int scsi_eh_get_sense(struct list_head *work_q,
struct list_head *done_q);
int scsi_noretry_cmd(struct scsi_cmnd *scmd);
/* scsi_lib.c */
extern int scsi_maybe_unblock_host(struct scsi_device *sdev);
extern void scsi_device_unbusy(struct scsi_device *sdev);
extern int scsi_queue_insert(struct scsi_cmnd *cmd, int reason);
extern void scsi_next_command(struct scsi_cmnd *cmd);
extern void scsi_io_completion(struct scsi_cmnd *, unsigned int);
extern void scsi_run_host_queues(struct Scsi_Host *shost);
extern struct request_queue *scsi_alloc_queue(struct scsi_device *sdev);
extern void scsi_free_queue(struct request_queue *q);
extern int scsi_init_queue(void);
extern void scsi_exit_queue(void);
struct request_queue;
struct request;
extern struct kmem_cache *scsi_sdb_cache;
/* scsi_proc.c */
#ifdef CONFIG_SCSI_PROC_FS
extern void scsi_proc_hostdir_add(struct scsi_host_template *);
extern void scsi_proc_hostdir_rm(struct scsi_host_template *);
extern void scsi_proc_host_add(struct Scsi_Host *);
extern void scsi_proc_host_rm(struct Scsi_Host *);
extern int scsi_init_procfs(void);
extern void scsi_exit_procfs(void);
#else
# define scsi_proc_hostdir_add(sht) do { } while (0)
# define scsi_proc_hostdir_rm(sht) do { } while (0)
# define scsi_proc_host_add(shost) do { } while (0)
# define scsi_proc_host_rm(shost) do { } while (0)
# define scsi_init_procfs() (0)
# define scsi_exit_procfs() do { } while (0)
#endif /* CONFIG_PROC_FS */
/* scsi_scan.c */
extern int scsi_complete_async_scans(void);
extern int scsi_scan_host_selected(struct Scsi_Host *, unsigned int,
unsigned int, unsigned int, int);
extern void scsi_forget_host(struct Scsi_Host *);
extern void scsi_rescan_device(struct device *);
/* scsi_sysctl.c */
#ifdef CONFIG_SYSCTL
extern int scsi_init_sysctl(void);
extern void scsi_exit_sysctl(void);
#else
# define scsi_init_sysctl() (0)
# define scsi_exit_sysctl() do { } while (0)
#endif /* CONFIG_SYSCTL */
/* scsi_sysfs.c */
extern int scsi_sysfs_add_sdev(struct scsi_device *);
extern int scsi_sysfs_add_host(struct Scsi_Host *);
extern int scsi_sysfs_register(void);
extern void scsi_sysfs_unregister(void);
extern void scsi_sysfs_device_initialize(struct scsi_device *);
extern int scsi_sysfs_target_initialize(struct scsi_device *);
extern struct scsi_transport_template blank_transport_template;
extern void __scsi_remove_device(struct scsi_device *);
extern struct bus_type scsi_bus_type;
extern const struct attribute_group *scsi_sysfs_shost_attr_groups[];
/* scsi_netlink.c */
#ifdef CONFIG_SCSI_NETLINK
extern void scsi_netlink_init(void);
extern void scsi_netlink_exit(void);
extern struct sock *scsi_nl_sock;
#else
static inline void scsi_netlink_init(void) {}
static inline void scsi_netlink_exit(void) {}
#endif
/* scsi_pm.c */
#ifdef CONFIG_PM
extern const struct dev_pm_ops scsi_bus_pm_ops;
#endif
#ifdef CONFIG_PM_RUNTIME
extern void scsi_autopm_get_target(struct scsi_target *);
extern void scsi_autopm_put_target(struct scsi_target *);
extern int scsi_autopm_get_host(struct Scsi_Host *);
extern void scsi_autopm_put_host(struct Scsi_Host *);
#else
static inline void scsi_autopm_get_target(struct scsi_target *t) {}
static inline void scsi_autopm_put_target(struct scsi_target *t) {}
static inline int scsi_autopm_get_host(struct Scsi_Host *h) { return 0; }
static inline void scsi_autopm_put_host(struct Scsi_Host *h) {}
#endif /* CONFIG_PM_RUNTIME */
/*
* internal scsi timeout functions: for use by mid-layer and transport
* classes.
*/
#define SCSI_DEVICE_BLOCK_MAX_TIMEOUT 600 /* units in seconds */
extern int scsi_internal_device_block(struct scsi_device *sdev);
extern int scsi_internal_device_unblock(struct scsi_device *sdev);
#endif /* _SCSI_PRIV_H */