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freebsd-skq/sys/cam/scsi/scsi_enc_internal.h
ken ff1edb089b Fix a device departure bug for the the pass(4), enc(4), sg(4) and ch(4) 
drivers.

The bug occurrs when a userland process has the driver instance
open and the underlying device goes away.  We get the devfs
callback that the device node has been destroyed, but not all of
the closes necessary to fully decrement the reference count on the
CAM peripheral.

The reason is that once devfs calls back and says the device has
been destroyed, it is moved off to deadfs, and devfs guarantees
that there will be no more open or close calls.  So the solution
is to keep track of how many outstanding open calls there are on
the device, and just release that many references when we get the
callback from devfs.

scsi_pass.c,
scsi_enc.c,
scsi_enc_internal.h:	Add an open count to the softc in these
			drivers.  Increment it on open and
			decrement it on close.

			When we get a devfs callback to say that
			the device node has gone away, decrement
			the peripheral reference count by the
			number of still outstanding opens.

			Make sure we don't access the peripheral
			with cam_periph_unlock() after what might
			be the final call to
			cam_periph_release_locked().  The
			peripheral might have been freed, and we
			will be dereferencing freed memory.

scsi_ch.c,
scsi_sg.c:		For the ch(4) and sg(4) drivers, add the
			same changes described above, and in
			addition, fix another bug that was
			previously fixed in the pass(4) and enc(4)
			drivers.

			These drivers were calling destroy_dev()
			from their cleanup routine, but that could
			cause a deadlock because the cleanup
			routine could be indirectly called from
			the driver's close routine.  This would
			cause a deadlock, because the device node
			is being held open by the active close
			call, and can't be destroyed.

Sponsored by:	Spectra Logic Corporation
MFC after:	1 week
2012-12-08 04:03:04 +00:00

232 lines
7.3 KiB
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/*-
* Copyright (c) 2000 Matthew Jacob
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification, immediately at the beginning of the file.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
/*
* This file contains definitions only intended for use within
* sys/cam/scsi/scsi_enc*.c, and not in other kernel components.
*/
#ifndef __SCSI_ENC_INTERNAL_H__
#define __SCSI_ENC_INTERNAL_H__
typedef struct enc_element {
uint32_t
enctype : 8, /* enclosure type */
subenclosure : 8, /* subenclosure id */
svalid : 1, /* enclosure information valid */
overall_status_elem: 1,/*
* This object represents generic
* status about all objects of this
* type.
*/
priv : 14; /* private data, per object */
uint8_t encstat[4]; /* state && stats */
uint8_t *physical_path; /* Device physical path data. */
u_int physical_path_len; /* Length of device path data. */
void *elm_private; /* per-type object data */
} enc_element_t;
typedef enum {
ENC_NONE,
ENC_SES_SCSI2,
ENC_SES,
ENC_SES_PASSTHROUGH,
ENC_SEN,
ENC_SAFT,
ENC_SEMB_SES,
ENC_SEMB_SAFT
} enctyp;
/* Platform Independent Driver Internal Definitions for enclosure devices. */
typedef struct enc_softc enc_softc_t;
struct enc_fsm_state;
typedef int fsm_fill_handler_t(enc_softc_t *ssc,
struct enc_fsm_state *state,
union ccb *ccb,
uint8_t *buf);
typedef int fsm_error_handler_t(union ccb *ccb, uint32_t cflags,
uint32_t sflags);
typedef int fsm_done_handler_t(enc_softc_t *ssc,
struct enc_fsm_state *state, union ccb *ccb,
uint8_t **bufp, int error, int xfer_len);
struct enc_fsm_state {
const char *name;
int page_code;
size_t buf_size;
uint32_t timeout;
fsm_fill_handler_t *fill;
fsm_done_handler_t *done;
fsm_error_handler_t *error;
};
typedef int (enc_softc_init_t)(enc_softc_t *);
typedef void (enc_softc_invalidate_t)(enc_softc_t *);
typedef void (enc_softc_cleanup_t)(enc_softc_t *);
typedef int (enc_init_enc_t)(enc_softc_t *);
typedef int (enc_get_enc_status_t)(enc_softc_t *, int);
typedef int (enc_set_enc_status_t)(enc_softc_t *, encioc_enc_status_t, int);
typedef int (enc_get_elm_status_t)(enc_softc_t *, encioc_elm_status_t *, int);
typedef int (enc_set_elm_status_t)(enc_softc_t *, encioc_elm_status_t *, int);
typedef int (enc_get_elm_desc_t)(enc_softc_t *, encioc_elm_desc_t *);
typedef int (enc_get_elm_devnames_t)(enc_softc_t *, encioc_elm_devnames_t *);
typedef int (enc_handle_string_t)(enc_softc_t *, encioc_string_t *, int);
typedef void (enc_device_found_t)(enc_softc_t *);
typedef void (enc_poll_status_t)(enc_softc_t *);
struct enc_vec {
enc_softc_invalidate_t *softc_invalidate;
enc_softc_cleanup_t *softc_cleanup;
enc_init_enc_t *init_enc;
enc_get_enc_status_t *get_enc_status;
enc_set_enc_status_t *set_enc_status;
enc_get_elm_status_t *get_elm_status;
enc_set_elm_status_t *set_elm_status;
enc_get_elm_desc_t *get_elm_desc;
enc_get_elm_devnames_t *get_elm_devnames;
enc_handle_string_t *handle_string;
enc_device_found_t *device_found;
enc_poll_status_t *poll_status;
};
typedef struct enc_cache {
enc_element_t *elm_map; /* objects */
int nelms; /* number of objects */
encioc_enc_status_t enc_status; /* overall status */
void *private; /* per-type private data */
} enc_cache_t;
/* Enclosure instance toplevel structure */
struct enc_softc {
enctyp enc_type; /* type of enclosure */
struct enc_vec enc_vec; /* vector to handlers */
void *enc_private; /* per-type private data */
/**
* "Published" configuration and state data available to
* external consumers.
*/
enc_cache_t enc_cache;
/**
* Configuration and state data being actively updated
* by the enclosure daemon.
*/
enc_cache_t enc_daemon_cache;
struct sx enc_cache_lock;
uint8_t enc_flags;
#define ENC_FLAG_INVALID 0x01
#define ENC_FLAG_INITIALIZED 0x02
#define ENC_FLAG_SHUTDOWN 0x04
union ccb saved_ccb;
struct cdev *enc_dev;
struct cam_periph *periph;
int open_count;
/* Bitmap of pending operations. */
uint32_t pending_actions;
/* The action on which the state machine is currently working. */
uint32_t current_action;
#define ENC_UPDATE_NONE 0x00
#define ENC_UPDATE_INVALID 0xff
/* Callout for auto-updating enclosure status */
struct callout status_updater;
struct proc *enc_daemon;
struct enc_fsm_state *enc_fsm_states;
struct intr_config_hook enc_boot_hold_ch;
};
static inline enc_cache_t *
enc_other_cache(enc_softc_t *enc, enc_cache_t *primary)
{
return (primary == &enc->enc_cache
? &enc->enc_daemon_cache : &enc->enc_cache);
}
/* SES Management mode page - SES2r20 Table 59 */
struct ses_mgmt_mode_page {
struct scsi_mode_header_6 header;
struct scsi_mode_blk_desc blk_desc;
uint8_t byte0; /* ps : 1, spf : 1, page_code : 6 */
#define SES_MGMT_MODE_PAGE_CODE 0x14
uint8_t length;
#define SES_MGMT_MODE_PAGE_LEN 6
uint8_t reserved[3];
uint8_t byte5; /* reserved : 7, enbltc : 1 */
#define SES_MGMT_TIMED_COMP_EN 0x1
uint8_t max_comp_time[2];
};
/* Enclosure core interface for sub-drivers */
int enc_runcmd(struct enc_softc *, char *, int, char *, int *);
void enc_log(struct enc_softc *, const char *, ...);
void enc_done(struct cam_periph *, union ccb *);
int enc_error(union ccb *, uint32_t, uint32_t);
void enc_update_request(enc_softc_t *, uint32_t);
/* SES Native interface */
enc_softc_init_t ses_softc_init;
/* SAF-TE interface */
enc_softc_init_t safte_softc_init;
/* Helper macros */
MALLOC_DECLARE(M_SCSIENC);
#define ENC_CFLAGS CAM_RETRY_SELTO
#define ENC_FLAGS SF_NO_PRINT | SF_RETRY_UA
#define STRNCMP strncmp
#define PRINTF printf
#define ENC_LOG enc_log
#if defined(DEBUG) || defined(ENC_DEBUG)
#define ENC_DLOG enc_log
#else
#define ENC_DLOG if (0) enc_log
#endif
#define ENC_VLOG if (bootverbose) enc_log
#define ENC_MALLOC(amt) malloc(amt, M_SCSIENC, M_NOWAIT)
#define ENC_MALLOCZ(amt) malloc(amt, M_SCSIENC, M_ZERO|M_NOWAIT)
/* Cast away const avoiding GCC warnings. */
#define ENC_FREE(ptr) free((void *)((uintptr_t)ptr), M_SCSIENC)
#define ENC_FREE_AND_NULL(ptr) do { \
if (ptr != NULL) { \
ENC_FREE(ptr); \
ptr = NULL; \
} \
} while(0)
#define MEMZERO bzero
#define MEMCPY(dest, src, amt) bcopy(src, dest, amt)
#endif /* __SCSI_ENC_INTERNAL_H__ */
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