freebsd-skq/sys/dev/vinum/request.h
grog ac9c8c9469 Modify the manner in which we lock RAID-5 plexes. This appears to
solve some of the elusive panics we have seen with corrupted buffer
headers (specifically the zeroed-out b_iodone field).

Submitted-by:	      Bernd Walter <ticso@cicely.de>
2000-01-05 06:09:43 +00:00

258 lines
10 KiB
C

/*-
* Copyright (c) 1997, 1998
* Nan Yang Computer Services Limited. All rights reserved.
*
* This software is distributed under the so-called ``Berkeley
* License'':
*
* 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.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Nan Yang Computer
* Services Limited.
* 4. Neither the name of the Company nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* This software is provided ``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 company 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.
*
* $Id: request.h,v 1.17 1999/12/27 02:18:05 grog Exp grog $
* $FreeBSD$
*/
/* Information needed to set up a transfer */
enum xferinfo {
XFR_NORMAL_READ = 1,
XFR_NORMAL_WRITE = 2, /* write request in normal mode */
XFR_RECOVERY_READ = 4,
XFR_DEGRADED_WRITE = 8,
XFR_PARITYLESS_WRITE = 0x10,
XFR_NO_PARITY_STRIPE = 0x20, /* parity stripe is not available */
XFR_DATA_BLOCK = 0x40, /* data block in request */
XFR_PARITY_BLOCK = 0x80, /* parity block in request */
XFR_BAD_SUBDISK = 0x100, /* this subdisk is dead */
XFR_MALLOCED = 0x200, /* this buffer is malloced */
#if VINUMDEBUG
XFR_PHASE2 = 0x800, /* documentation only: 2nd phase write */
#endif
XFR_REVIVECONFLICT = 0x1000, /* possible conflict with a revive operation */
/* operations that need a parity block */
XFR_PARITYOP = (XFR_NORMAL_WRITE | XFR_RECOVERY_READ | XFR_DEGRADED_WRITE),
/* operations that use the group parameters */
XFR_GROUPOP = (XFR_DEGRADED_WRITE | XFR_RECOVERY_READ),
/* operations that that use the data parameters */
XFR_DATAOP = (XFR_NORMAL_READ | XFR_NORMAL_WRITE | XFR_PARITYLESS_WRITE),
/* operations requiring read before write */
XFR_RBW = (XFR_NORMAL_WRITE | XFR_DEGRADED_WRITE),
/* operations that need a malloced buffer */
XFR_NEEDS_MALLOC = (XFR_NORMAL_WRITE | XFR_RECOVERY_READ | XFR_DEGRADED_WRITE)
};
/*
* Describe one low-level request, part of a
* high-level request. This is an extended
* struct buf buffer, and the first element
* *must* be a struct buf. We pass this
* structure to the I/O routines instead of a
* struct buf in order to be able to locate the
* high-level request when it completes.
*
* All offsets and lengths are in sectors.
*/
struct rqelement {
struct buf b; /* buf structure */
struct rqgroup *rqg; /* pointer to our group */
/* Information about the transfer */
daddr_t sdoffset; /* offset in subdisk */
int useroffset; /* offset in user buffer of normal data */
/*
* dataoffset and datalen refer to "individual" data
* transfers which involve only this drive (normal read,
* parityless write) and also degraded write.
*
* groupoffset and grouplen refer to the other "group"
* operations (normal write, recovery read) which involve
* more than one drive. Both the offsets are relative to
* the start of the local buffer.
*/
int dataoffset; /* offset in buffer of the normal data */
int groupoffset; /* offset in buffer of group data */
short datalen; /* length of normal data (sectors) */
short grouplen; /* length of group data (sectors) */
short buflen; /* total buffer length to allocate */
short flags; /* really enum xferinfo (see above) */
/* Ways to find other components */
short sdno; /* subdisk number */
short driveno; /* drive number */
};
/*
* A group of requests built to satisfy an I/O
* transfer on a single plex.
*/
struct rqgroup {
struct rqgroup *next; /* pointer to next group */
struct request *rq; /* pointer to the request */
short count; /* number of requests in this group */
short active; /* and number active */
short plexno; /* index of plex */
int badsdno; /* index of bad subdisk or -1 */
enum xferinfo flags; /* description of transfer */
struct rangelock *lock; /* lock for this transfer */
daddr_t lockbase; /* and lock address */
struct rqelement rqe[0]; /* and the elements of this request */
};
/*
* Describe one high-level request and the
* work we have to do to satisfy it.
*/
struct request {
struct buf *bp; /* pointer to the high-level request */
enum xferinfo flags;
union {
int volno; /* volume index */
int plexno; /* or plex index */
} volplex;
int error; /* current error indication */
int sdno; /* reviving subdisk (XFR_REVIVECONFLICT) */
short isplex; /* set if this is a plex request */
short active; /* number of subrequests still active */
struct rqgroup *rqg; /* pointer to the first group of requests */
struct rqgroup *lrqg; /* and to the last group of requests */
struct request *next; /* link of waiting requests */
};
/*
* Extended buffer header for subdisk I/O. Includes
* a pointer to the user I/O request.
*/
struct sdbuf {
struct buf b; /* our buffer */
struct buf *bp; /* and pointer to parent */
short driveno; /* drive index */
short sdno; /* and subdisk index */
};
/*
* Values returned by rqe and friends. Be careful
* with these: they are in order of increasing
* seriousness. Some routines check for
* > REQUEST_RECOVERED to indicate a failed request. XXX
*/
enum requeststatus {
REQUEST_OK, /* request built OK */
REQUEST_RECOVERED, /* request OK, but involves RAID5 recovery */
REQUEST_DEGRADED, /* parts of request failed */
REQUEST_EOF, /* parts of request failed: outside plex */
REQUEST_DOWN, /* all of request failed: subdisk(s) down */
REQUEST_ENOMEM /* all of request failed: ran out of memory */
};
#ifdef VINUMDEBUG
/* Trace entry for request info (DEBUG_LASTREQS) */
enum rqinfo_type {
loginfo_unused, /* never been used */
loginfo_user_bp, /* this is the bp when strategy is called */
loginfo_user_bpl, /* and this is the bp at launch time */
loginfo_rqe, /* user RQE */
loginfo_iodone, /* iodone */
loginfo_raid5_data, /* write RAID-5 data block */
loginfo_raid5_parity, /* write RAID-5 parity block */
loginfo_sdio, /* subdisk I/O */
loginfo_sdiol, /* subdisk I/O launch */
loginfo_sdiodone, /* subdisk iodone */
loginfo_lockwait, /* wait for range lock */
loginfo_lock, /* lock range */
loginfo_unlock, /* unlock range */
};
union rqinfou { /* info to pass to logrq */
struct buf *bp;
struct rqelement *rqe; /* address of request, for correlation */
struct rangelock *lockinfo;
};
struct rqinfo {
enum rqinfo_type type; /* kind of event */
struct timeval timestamp; /* time it happened */
struct buf *bp; /* point to user buffer */
int devmajor; /* major and minor device info */
int devminor;
union {
struct buf b; /* yup, the *whole* buffer header */
struct rqelement rqe; /* and the whole rqe */
struct rangelock lockinfo;
} info;
};
#define RQINFO_SIZE 128 /* number of info slots in buffer */
void logrq(enum rqinfo_type type, union rqinfou info, struct buf *ubp);
#endif
/* Structures for the daemon */
/* types of request to the daemon */
enum daemonrq {
daemonrq_none, /* dummy to catch bugs */
daemonrq_ioerror, /* error occurred on I/O */
daemonrq_saveconfig, /* save configuration */
daemonrq_return, /* return to userland */
daemonrq_ping, /* show sign of life */
daemonrq_init, /* initialize a plex */
daemonrq_revive, /* revive a subdisk */
daemonrq_closedrive, /* close a drive */
};
/* info field for daemon requests */
union daemoninfo { /* and the request information */
struct request *rq; /* for daemonrq_ioerror */
struct sd *sd; /* for daemonrq_revive */
struct plex *plex; /* for daemonrq_init */
struct drive *drive; /* for daemonrq_closedrive */
int nothing; /* for passing NULL */
};
struct daemonq {
struct daemonq *next; /* pointer to next element in queue */
enum daemonrq type; /* type of request */
int privateinuse; /* private element, being used */
union daemoninfo info; /* and the request information */
};
void queue_daemon_request(enum daemonrq type, union daemoninfo info);
extern int daemon_options;
enum daemon_option {
daemon_verbose = 1, /* talk about what we're doing */
daemon_stopped = 2,
daemon_noupdate = 4, /* don't update the disk config, for recovery */
};
void freerq(struct request *rq);
void unlockrange(int plexno, struct rangelock *);
/* Local Variables: */
/* fill-column: 50 */
/* End: */