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freebsd-dev/sys/dev/vinum/vinumrequest.c
Greg Lehey 47ffaa06f1 Close any drives downed in an interrupt context. 
Ensure correct order of requests.
Call launch_requests at splhigh to see if this stops the mysterious
SMP panics
1998-11-02 04:09:34 +00:00

967 lines
34 KiB
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/* XXX to do:
* Decide where we need splbio ()
*/
/*-
* 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.c,v 1.19 1998/11/01 02:18:39 grog Exp grog $
*/
#define REALLYKERNEL
#include "vinumhdr.h"
#include "request.h"
#include <miscfs/specfs/specdev.h>
#include <sys/resourcevar.h>
/* pointer to ioctl p parameter, to save passing it around */
extern struct proc *myproc;
enum requeststatus bre(struct request *rq,
int plexno,
daddr_t * diskstart,
daddr_t diskend);
enum requeststatus bre5(struct request *rq,
int plexno,
daddr_t * diskstart,
daddr_t diskend);
enum requeststatus build_read_request(struct request *rq, int volplexno);
enum requeststatus build_write_request(struct request *rq);
enum requeststatus build_rq_buffer(struct rqelement *rqe, struct plex *plex);
void freerq(struct request *rq);
void free_rqg(struct rqgroup *rqg);
int find_alternate_sd(struct request *rq);
int check_range_covered(struct request *);
void complete_rqe(struct buf *bp);
void complete_raid5_write(struct rqelement *);
int abortrequest(struct request *rq, int error);
void sdio(struct buf *bp);
void sdio_done(struct buf *bp);
int vinum_bounds_check(struct buf *bp, struct volume *vol);
caddr_t allocdatabuf(struct rqelement *rqe);
void freedatabuf(struct rqelement *rqe);
#ifdef DEBUG
struct rqinfo rqinfo[RQINFO_SIZE];
struct rqinfo *rqip = rqinfo;
void
logrq(enum rqinfo_type type, union rqinfou info, struct buf *ubp)
{
BROKEN_GDB;
int s = splhigh();
vinum_conf.rqipp = &rqip; /* XXX for broken gdb */
vinum_conf.rqinfop = rqinfo; /* XXX for broken gdb */
#if __FreeBSD__ < 3
rqip->timestamp = time; /* when did this happen? */
#else
microtime(&rqip->timestamp); /* when did this happen? */
#endif
rqip->type = type;
rqip->bp = ubp; /* user buffer */
switch (type) {
case loginfo_user_bp:
case loginfo_user_bpl:
bcopy(info.bp, &rqip->info.b, sizeof(struct buf));
break;
case loginfo_iodone:
case loginfo_rqe:
case loginfo_raid5_data:
case loginfo_raid5_parity:
bcopy(info.rqe, &rqip->info.rqe, sizeof(struct rqelement));
break;
case loginfo_unused:
break;
}
rqip++;
if (rqip >= &rqinfo[RQINFO_SIZE]) /* wrap around */
rqip = rqinfo;
splx(s);
}
#endif
void
vinumstrategy(struct buf *bp)
{
BROKEN_GDB;
int volno;
struct volume *vol = NULL;
int s;
struct devcode *device = (struct devcode *) &bp->b_dev; /* decode device number */
enum requeststatus status;
/* We may have changed the configuration in
* an interrupt context. Update it now. It
* could change again, so do it in a loop.
* XXX this is broken and contains a race condition.
* The correct way is to hand it off the the Vinum
* daemon, but I haven't found a name for it yet */
while (vinum_conf.flags & VF_DIRTYCONFIG) { /* config is dirty, save it now */
int driveno;
vinum_conf.flags &= ~VF_DIRTYCONFIG; /* turn it off */
for (driveno = 0; driveno < vinum_conf.drives_used; driveno++) {
if ((DRIVE[driveno].state == drive_down) /* drive down */
&&(DRIVE[driveno].vp != NULL)) /* but still open */
close_drive(&DRIVE[driveno]); /* close it now */
}
save_config();
}
switch (device->type) {
case VINUM_SD_TYPE:
sdio(bp);
return;
/* In fact, vinum doesn't handle drives: they're
* handled directly by the disk drivers */
case VINUM_DRIVE_TYPE:
default:
bp->b_error = EIO; /* I/O error */
bp->b_flags |= B_ERROR;
biodone(bp);
return;
case VINUM_VOLUME_TYPE: /* volume I/O */
volno = VOLNO(bp->b_dev);
vol = &VOL[volno];
if (vol->state != volume_up) { /* can't access this volume */
bp->b_error = EIO; /* I/O error */
bp->b_flags |= B_ERROR;
biodone(bp);
return;
}
if (vinum_bounds_check(bp, vol) <= 0) { /* don't like them bounds */
biodone(bp); /* have nothing to do with this */
return;
}
/* FALLTHROUGH */
/* Plex I/O is pretty much the same as volume I/O
* for a single plex. Indicate this by passing a NULL
* pointer (set above) for the volume */
case VINUM_PLEX_TYPE:
bp->b_resid = bp->b_bcount; /* transfer everything */
vinumstart(bp, 0);
return;
}
}
/* Start a transfer. Return -1 on error,
* 0 if OK, 1 if we need to retry.
* Parameter reviveok is set when doing
* transfers for revives: it allows transfers to
* be started immediately when a revive is in
* progress. During revive, normal transfers
* are queued if they share address space with
* a currently active revive operation. */
int
vinumstart(struct buf *bp, int reviveok)
{
BROKEN_GDB;
int plexno;
int maxplex; /* maximum number of plexes to handle */
struct volume *vol;
struct rqgroup *rqg; /* current plex's requests */
struct rqelement *rqe; /* individual element */
struct request *rq; /* build up our request here */
int rqno; /* index in request list */
enum requeststatus status;
#if DEBUG
if (debug & DEBUG_LASTREQS)
logrq(loginfo_user_bp, bp, bp);
#endif
/* XXX In these routines, we're assuming that
* we will always be called with bp->b_bcount
* which is a multiple of the sector size. This
* is a reasonable assumption, since we are only
* called from system routines. Should we check
* anyway? */
if ((bp->b_bcount % DEV_BSIZE) != 0) { /* bad length */
bp->b_error = EINVAL; /* invalid size */
bp->b_flags |= B_ERROR;
biodone(bp);
return -1;
}
rq = (struct request *) Malloc(sizeof(struct request)); /* allocate a request struct */
if (rq == NULL) { /* can't do it */
bp->b_error = ENOMEM; /* can't get memory */
bp->b_flags |= B_ERROR;
biodone(bp);
return -1;
}
bzero(rq, sizeof(struct request));
/* Note the volume ID. This can be NULL, which
* the request building functions use as an
* indication for single plex I/O */
rq->bp = bp; /* and the user buffer struct */
if (DEVTYPE(bp->b_dev) == VINUM_VOLUME_TYPE) { /* it's a volume, */
rq->volplex.volno = VOLNO(bp->b_dev); /* get the volume number */
vol = &VOL[rq->volplex.volno]; /* and point to it */
vol->active++; /* one more active request */
maxplex = vol->plexes; /* consider all its plexes */
} else {
vol = NULL; /* no volume */
rq->volplex.plexno = PLEXNO(bp->b_dev); /* point to the plex */
rq->isplex = 1; /* note that it's a plex */
maxplex = 1; /* just the one plex */
}
if (bp->b_flags & B_READ) {
/* This is a read request. Decide
* which plex to read from.
*
* There's a potential race condition here,
* since we're not locked, and we could end
* up multiply incrementing the round-robin
* counter. This doesn't have any serious
* effects, however. */
if (vol != NULL) {
vol->reads++;
vol->bytes_read += bp->b_bcount;
plexno = vol->preferred_plex; /* get the plex to use */
if (plexno < 0) { /* round robin */
plexno = vol->last_plex_read;
vol->last_plex_read++;
if (vol->last_plex_read == vol->plexes) /* got the the end? */
vol->last_plex_read = 0; /* wrap around */
}
status = build_read_request(rq, plexno); /* build a request */
} else {
daddr_t diskaddr = bp->b_blkno; /* start offset of transfer */
status = bre(rq, /* build a request list */
rq->volplex.plexno,
&diskaddr,
diskaddr + (bp->b_bcount / DEV_BSIZE));
}
if ((status > REQUEST_RECOVERED) /* can't satisfy it */
||(bp->b_flags & B_DONE)) { /* XXX shouldn't get this without bad status */
if (status == REQUEST_DOWN) { /* not enough subdisks */
bp->b_error = EIO; /* I/O error */
bp->b_flags |= B_ERROR;
}
biodone(bp);
freerq(rq);
return -1;
} { /* XXX */
int result;
int s = splhigh();
result = launch_requests(rq, reviveok); /* now start the requests if we can */
splx(s);
return result;
}
} else
/* This is a write operation. We write to all
* plexes. If this is a RAID 5 plex, we must also
* update the parity stripe. */
{
if (vol != NULL) {
vol->writes++;
vol->bytes_written += bp->b_bcount;
status = build_write_request(rq); /* Not all the subdisks are up */
} else { /* plex I/O */
daddr_t diskstart;
diskstart = bp->b_blkno; /* start offset of transfer */
status = bre(rq,
PLEXNO(bp->b_dev),
&diskstart,
bp->b_blkno + (bp->b_bcount / DEV_BSIZE)); /* build requests for the plex */
}
if ((status > REQUEST_RECOVERED) /* can't satisfy it */
||(bp->b_flags & B_DONE)) { /* XXX shouldn't get this without bad status */
if (status == REQUEST_DOWN) { /* not enough subdisks */
bp->b_error = EIO; /* I/O error */
bp->b_flags |= B_ERROR;
}
if ((bp->b_flags & B_DONE) == 0)
biodone(bp);
freerq(rq);
return -1;
} { /* XXX */
int result;
int s = splhigh();
result = launch_requests(rq, reviveok); /* now start the requests if we can */
splx(s);
return result;
}
/* return launch_requests (rq, reviveok); *//* start the requests */
}
}
/* Call the low-level strategy routines to
* perform the requests in a struct request */
int
launch_requests(struct request *rq, int reviveok)
{
struct rqgroup *rqg;
int rqno; /* loop index */
struct rqelement *rqe; /* current element */
int s;
/* First find out whether we're reviving, and the
* request contains a conflict. If so, we hang
* the request off plex->waitlist of the first
* plex we find which is reviving */
if ((rq->flags & XFR_REVIVECONFLICT) /* possible revive conflict */
&&(!reviveok)) { /* and we don't want to do it now, */
struct volume *vol = &VOL[VOLNO(rq->bp->b_dev)];
struct plex *plex;
int plexno;
for (plexno = 0; plexno < vol->plexes; plexno++) { /* find the reviving plex */
plex = &PLEX[vol->plex[plexno]];
if (plex->state == plex_reviving) /* found it */
break;
}
if (plexno < vol->plexes) { /* found it? */
struct request *waitlist = plex->waitlist; /* point to the waiting list */
while (waitlist->next != NULL) /* find the end */
waitlist = waitlist->next;
waitlist->next = rq; /* hook our request there */
return 0; /* and get out of here */
} else /* bad vinum, bad */
printf("vinum: can't find reviving plex for volume %s\n", vol->name);
}
rq->active = 0; /* nothing yet */
/* XXX This is probably due to a bug */
if (rq->rqg == NULL) { /* no request */
abortrequest(rq, EINVAL);
return -1;
}
#if DEBUG
if (debug & DEBUG_ADDRESSES)
printf("Request: %x\n%s dev 0x%x, offset 0x%x, length %ld\n",
(u_int) rq,
rq->bp->b_flags & B_READ ? "Read" : "Write",
rq->bp->b_dev,
rq->bp->b_blkno,
rq->bp->b_bcount); /* XXX */
vinum_conf.lastrq = (int) rq;
vinum_conf.lastbuf = rq->bp;
if (debug & DEBUG_LASTREQS)
logrq(loginfo_user_bpl, rq->bp, rq->bp);
#endif
for (rqg = rq->rqg; rqg != NULL; rqg = rqg->next) { /* through the whole request chain */
rqg->active = rqg->count; /* they're all active */
rq->active++; /* one more active request group */
for (rqno = 0; rqno < rqg->count; rqno++) {
rqe = &rqg->rqe[rqno];
if (rqe->flags & XFR_BAD_SUBDISK) /* this subdisk is bad, */
rqg->active--; /* one less active request */
else {
struct drive *drive = &DRIVE[rqe->driveno]; /* drive to access */
if ((rqe->b.b_flags & B_READ) == 0)
rqe->b.b_vp->v_numoutput++; /* one more output going */
rqe->b.b_flags |= B_ORDERED; /* XXX chase SCSI driver */
#if DEBUG
if (debug & DEBUG_ADDRESSES)
printf(" %s dev 0x%x, sd %d, offset 0x%x, devoffset 0x%x, length %ld\n",
rqe->b.b_flags & B_READ ? "Read" : "Write",
rqe->b.b_dev,
rqe->sdno,
(u_int) (rqe->b.b_blkno - SD[rqe->sdno].driveoffset),
rqe->b.b_blkno,
rqe->b.b_bcount); /* XXX */
if (debug & DEBUG_NUMOUTPUT)
printf(" vinumstart sd %d numoutput %ld\n",
rqe->sdno,
rqe->b.b_vp->v_numoutput);
if (debug & DEBUG_LASTREQS)
logrq(loginfo_rqe, rqe, rq->bp);
#endif
/* fire off the request */
s = splbio();
(*bdevsw[major(rqe->b.b_dev)]->d_strategy) (&rqe->b);
splx(s);
}
/* XXX Do we need caching? Think about this more */
}
}
return 0;
}
/* define the low-level requests needed to perform a
* high-level I/O operation for a specific plex 'plexno'.
*
* Return 0 if all subdisks involved in the request are up, 1 if some
* subdisks are not up, and -1 if the request is at least partially
* outside the bounds of the subdisks.
*
* Modify the pointer *diskstart to point to the end address. On
* read, return on the first bad subdisk, so that the caller
* (build_read_request) can try alternatives.
*
* On entry to this routine, the rqg structures are not assigned. The
* assignment is performed by expandrq(). Strictly speaking, the
* elements rqe->sdno of all entries should be set to -1, since 0
* (from bzero) is a valid subdisk number. We avoid this problem by
* initializing the ones we use, and not looking at the others (index
* >= rqg->requests).
*/
enum requeststatus
bre(struct request *rq,
int plexno,
daddr_t * diskaddr,
daddr_t diskend)
{
BROKEN_GDB;
int sdno;
struct sd *sd;
struct rqgroup *rqg;
struct buf *bp; /* user's bp */
struct plex *plex;
enum requeststatus status; /* return value */
daddr_t plexoffset; /* offset of transfer in plex */
daddr_t stripebase; /* base address of stripe (1st subdisk) */
daddr_t stripeoffset; /* offset in stripe */
daddr_t blockoffset; /* offset in stripe on subdisk */
struct rqelement *rqe; /* point to this request information */
daddr_t diskstart = *diskaddr; /* remember where this transfer starts */
bp = rq->bp; /* buffer pointer */
status = REQUEST_OK; /* return value: OK until proven otherwise */
plex = &PLEX[plexno]; /* point to the plex */
switch (plex->organization) {
case plex_concat:
for (sdno = 0; sdno < plex->subdisks; sdno++) {
sd = &SD[plex->sdnos[sdno]];
if ((*diskaddr < (sd->plexoffset + sd->sectors)) /* The request starts before the end of this */
&&(diskend > sd->plexoffset)) { /* subdisk and ends after the start of this sd */
if ((sd->state != sd_up) || (plex->state != plex_up)) {
enum requeststatus s;
s = checksdstate(sd, rq, *diskaddr, diskend); /* do we need to change state? */
if (s) /* give up? */
return s; /* yup */
}
rqg = allocrqg(rq, 1); /* space for the request */
if (rqg == NULL) { /* malloc failed */
bp->b_flags |= B_ERROR;
bp->b_error = ENOMEM;
biodone(bp);
return REQUEST_ENOMEM;
}
rqg->plexno = plexno;
rqe = &rqg->rqe[0]; /* point to the element */
rqe->rqg = rqg; /* group */
rqe->sdno = sd->sdno; /* put in the subdisk number */
plexoffset = max(sd->plexoffset, *diskaddr); /* start offset in plex */
rqe->sdoffset = plexoffset - sd->plexoffset; /* start offset in subdisk */
rqe->useroffset = plexoffset - diskstart; /* start offset in user buffer */
rqe->dataoffset = 0;
rqe->datalen = min(diskend - *diskaddr, /* number of sectors to transfer in this sd */
sd->sectors - rqe->sdoffset);
rqe->groupoffset = 0; /* no groups for concatenated plexes */
rqe->grouplen = 0;
rqe->buflen = rqe->datalen; /* buffer length is data buffer length */
rqe->flags = 0;
rqe->driveno = sd->driveno;
*diskaddr += rqe->datalen; /* bump the address */
if (build_rq_buffer(rqe, plex)) { /* build the buffer */
deallocrqg(rqg);
bp->b_flags |= B_ERROR;
bp->b_error = ENOMEM;
biodone(bp);
return REQUEST_ENOMEM; /* can't do it */
}
}
if (*diskaddr > diskend) /* we're finished, */
break; /* get out of here */
}
break;
case plex_striped:
{
while (*diskaddr < diskend) { /* until we get it all sorted out */
/* The offset of the start address from
* the start of the stripe */
stripeoffset = *diskaddr % (plex->stripesize * plex->subdisks);
/* The plex-relative address of the
* start of the stripe */
stripebase = *diskaddr - stripeoffset;
/* The number of the subdisk in which
* the start is located */
sdno = stripeoffset / plex->stripesize;
/* The offset from the beginning of the stripe
* on this subdisk */
blockoffset = stripeoffset % plex->stripesize;
sd = &SD[plex->sdnos[sdno]]; /* the subdisk in question */
if ((sd->state != sd_up) || (plex->state != plex_up)) {
enum requeststatus s;
s = checksdstate(sd, rq, *diskaddr, diskend); /* do we need to change state? */
if (s) /* give up? */
return s; /* yup */
}
rqg = allocrqg(rq, 1); /* space for the request */
if (rqg == NULL) { /* malloc failed */
bp->b_flags |= B_ERROR;
bp->b_error = ENOMEM;
biodone(bp);
return REQUEST_ENOMEM;
}
rqg->plexno = plexno;
rqe = &rqg->rqe[0]; /* point to the element */
rqe->rqg = rqg;
rqe->sdoffset = stripebase / plex->subdisks + blockoffset; /* start offset in this subdisk */
rqe->useroffset = *diskaddr - diskstart; /* The offset of the start in the user buffer */
rqe->dataoffset = 0;
rqe->datalen = min(diskend - *diskaddr, /* the amount remaining to transfer */
plex->stripesize - blockoffset); /* and the amount left in this stripe */
rqe->groupoffset = 0; /* no groups for striped plexes */
rqe->grouplen = 0;
rqe->buflen = rqe->datalen; /* buffer length is data buffer length */
rqe->flags = 0;
rqe->sdno = sd->sdno; /* put in the subdisk number */
rqe->driveno = sd->driveno;
if (rqe->sdoffset >= sd->sectors) { /* starts beyond the end of the subdisk? */
deallocrqg(rqg);
return REQUEST_EOF;
} else if (rqe->sdoffset + rqe->datalen > sd->sectors) /* ends beyond the end of the subdisk? */
rqe->datalen = sd->sectors - rqe->sdoffset; /* yes, truncate */
if (build_rq_buffer(rqe, plex)) { /* build the buffer */
deallocrqg(rqg);
bp->b_flags |= B_ERROR;
bp->b_error = ENOMEM;
biodone(bp);
return REQUEST_ENOMEM; /* can't do it */
}
*diskaddr += rqe->datalen; /* look at the remainder */
if (*diskaddr < diskend) { /* didn't finish the request on this stripe */
plex->multiblock++; /* count another one */
if (sdno == plex->subdisks - 1) /* last subdisk, */
plex->multistripe++; /* another stripe as well */
}
}
}
break;
default:
printf("vinum: invalid plex type in bre");
}
return status;
}
/* Build up a request structure for reading volumes.
* This function is not needed for plex reads, since there's
* no recovery if a plex read can't be satisified. */
enum requeststatus
build_read_request(struct request *rq, /* request */
int plexindex)
{ /* index in the volume's plex table */
BROKEN_GDB;
struct buf *bp;
daddr_t startaddr; /* offset of previous part of transfer */
daddr_t diskaddr; /* offset of current part of transfer */
daddr_t diskend; /* and end offset of transfer */
int plexno; /* plex index in vinum_conf */
struct rqgroup *rqg; /* point to the request we're working on */
struct volume *vol; /* volume in question */
off_t oldstart; /* note where we started */
int recovered = 0; /* set if we recover a read */
enum requeststatus status = REQUEST_OK;
bp = rq->bp; /* buffer pointer */
diskaddr = bp->b_blkno; /* start offset of transfer */
diskend = diskaddr + (bp->b_bcount / DEV_BSIZE); /* and end offset of transfer */
rqg = &rq->rqg[plexindex]; /* plex request */
vol = &VOL[rq->volplex.volno]; /* point to volume */
while (diskaddr < diskend) { /* build up request components */
startaddr = diskaddr;
status = bre(rq, vol->plex[plexindex], &diskaddr, diskend); /* build up a request */
switch (status) {
case REQUEST_OK:
continue;
case REQUEST_RECOVERED:
recovered = 1;
break;
case REQUEST_EOF:
case REQUEST_ENOMEM:
return status;
/* if we get here, we have either had a failure or
* a RAID 5 recovery. We don't want to use the
* recovery, because it's expensive, so first we
* check if we have alternatives */
case REQUEST_DOWN: /* can't access the plex */
if (vol != NULL) { /* and this is volume I/O */
/* Try to satisfy the request
* from another plex */
for (plexno = 0; plexno < vol->plexes; plexno++) {
diskaddr = startaddr; /* start at the beginning again */
oldstart = startaddr; /* and note where that was */
if (plexno != plexindex) { /* don't try this plex again */
bre(rq, vol->plex[plexno], &diskaddr, diskend); /* try a request */
if (diskaddr > oldstart) { /* we satisfied another part */
recovered = 1; /* we recovered from the problem */
status = REQUEST_OK; /* don't complain about it */
break;
}
}
if (plexno == (vol->plexes - 1)) /* couldn't satisfy the request */
return REQUEST_DOWN; /* failed */
}
} else
return REQUEST_DOWN; /* bad luck */
}
if (recovered)
vol->recovered_reads += recovered; /* adjust our recovery count */
}
return status;
}
/* Build up a request structure for writes.
* Return 0 if all subdisks involved in the request are up, 1 if some
* subdisks are not up, and -1 if the request is at least partially
* outside the bounds of the subdisks. */
enum requeststatus
build_write_request(struct request *rq)
{ /* request */
BROKEN_GDB;
struct buf *bp;
daddr_t diskstart; /* offset of current part of transfer */
daddr_t diskend; /* and end offset of transfer */
int plexno; /* plex index in vinum_conf */
struct volume *vol; /* volume in question */
enum requeststatus status;
bp = rq->bp; /* buffer pointer */
vol = &VOL[rq->volplex.volno]; /* point to volume */
diskend = bp->b_blkno + (bp->b_bcount / DEV_BSIZE); /* end offset of transfer */
status = REQUEST_OK;
for (plexno = 0; plexno < vol->plexes; plexno++) {
diskstart = bp->b_blkno; /* start offset of transfer */
status = min(status, bre(rq, /* build requests for the plex */
vol->plex[plexno],
&diskstart,
diskend));
}
return status;
}
/* Fill in the struct buf part of a request element. */
enum requeststatus
build_rq_buffer(struct rqelement *rqe, struct plex *plex)
{
BROKEN_GDB;
struct sd *sd; /* point to subdisk */
struct volume *vol;
struct buf *bp;
struct buf *ubp; /* user (high level) buffer header */
vol = &VOL[rqe->rqg->rq->volplex.volno];
sd = &SD[rqe->sdno]; /* point to subdisk */
bp = &rqe->b;
ubp = rqe->rqg->rq->bp; /* pointer to user buffer header */
/* Initialize the buf struct */
bzero(&rqe->b, sizeof(struct buf));
bp->b_proc = ubp->b_proc; /* process pointer */
bp->b_flags = ubp->b_flags & (B_NOCACHE | B_READ | B_ASYNC); /* copy these flags from user bp */
bp->b_flags |= B_CALL | B_BUSY; /* inform us when it's done */
if (plex->state == plex_reviving)
bp->b_flags |= B_ORDERED; /* keep request order if we're reviving */
bp->b_iodone = complete_rqe; /* by calling us here */
bp->b_dev = DRIVE[rqe->driveno].dev; /* drive device */
bp->b_blkno = rqe->sdoffset + sd->driveoffset; /* start address */
bp->b_bcount = rqe->buflen << DEV_BSHIFT; /* number of bytes to transfer */
bp->b_resid = bp->b_bcount; /* and it's still all waiting */
bp->b_bufsize = bp->b_bcount; /* and buffer size */
bp->b_vp = DRIVE[rqe->driveno].vp; /* drive vnode */
bp->b_rcred = FSCRED; /* we have the file system credentials */
bp->b_wcred = FSCRED; /* we have the file system credentials */
if (rqe->flags & XFR_MALLOCED) { /* this operation requires a malloced buffer */
bp->b_data = Malloc(bp->b_bcount); /* get a buffer to put it in */
if (bp->b_data == NULL) { /* failed */
Debugger("XXX");
abortrequest(rqe->rqg->rq, ENOMEM);
return REQUEST_ENOMEM; /* no memory */
}
} else
/* Point directly to user buffer data. This means
* that we don't need to do anything when we have
* finished the transfer */
bp->b_data = ubp->b_data + rqe->useroffset * DEV_BSIZE;
return 0;
}
/* Abort a request: free resources and complete the
* user request with the specified error */
int
abortrequest(struct request *rq, int error)
{
struct buf *bp = rq->bp; /* user buffer */
bp->b_flags |= B_ERROR;
bp->b_error = error;
freerq(rq); /* free everything we're doing */
biodone(bp);
return error; /* and give up */
}
/* Check that our transfer will cover the
* complete address space of the user request.
*
* Return 1 if it can, otherwise 0 */
int
check_range_covered(struct request *rq)
{
/* XXX */
return 1;
}
/* Perform I/O on a subdisk */
void
sdio(struct buf *bp)
{
int s; /* spl */
struct sd *sd;
struct sdbuf *sbp;
daddr_t endoffset;
struct drive *drive;
sd = &SD[SDNO(bp->b_dev)]; /* point to the subdisk */
drive = &DRIVE[sd->driveno];
if (drive->state != drive_up) { /* XXX until we get the states fixed */
set_sd_state(SDNO(bp->b_dev), sd_obsolete, setstate_force);
bp->b_flags |= B_ERROR;
bp->b_error = EIO;
biodone(bp);
return;
}
/* XXX decide which states we will really accept here. up
* implies it could be involved with a plex, in which
* case we don't want to dick with it */
if ((sd->state != sd_up)
&& (sd->state != sd_initializing)
&& (sd->state != sd_reborn)) { /* we can't access it */
bp->b_flags |= B_ERROR;
bp->b_flags = EIO;
if (bp->b_flags & B_BUSY) /* XXX why isn't this always the case? */
biodone(bp);
return;
}
/* Get a buffer */
sbp = (struct sdbuf *) Malloc(sizeof(struct sdbuf));
if (sbp == NULL) {
bp->b_flags |= B_ERROR;
bp->b_error = ENOMEM;
biodone(bp);
return;
}
bcopy(bp, &sbp->b, sizeof(struct buf)); /* start with the user's buffer */
sbp->b.b_flags |= B_CALL; /* tell us when it's done */
sbp->b.b_iodone = sdio_done; /* here */
sbp->b.b_dev = DRIVE[sd->driveno].dev; /* device */
sbp->b.b_vp = DRIVE[sd->driveno].vp; /* vnode */
sbp->b.b_blkno += sd->driveoffset;
sbp->bp = bp; /* note the address of the original header */
sbp->sdno = sd->sdno; /* note for statistics */
sbp->driveno = sd->driveno;
endoffset = bp->b_blkno + sbp->b.b_bcount / DEV_BSIZE; /* final sector offset */
if (endoffset > sd->sectors) { /* beyond the end */
sbp->b.b_bcount -= (endoffset - sd->sectors) * DEV_BSIZE; /* trim */
if (sbp->b.b_bcount <= 0) { /* nothing to transfer */
bp->b_resid = bp->b_bcount; /* nothing transferred */
/* XXX Grrr. This doesn't seem to work. Return
* an error after all */
bp->b_flags |= B_ERROR;
bp->b_error = ENOSPC;
biodone(bp);
Free(sbp);
return;
}
}
if ((sbp->b.b_flags & B_READ) == 0) /* write */
sbp->b.b_vp->v_numoutput++; /* one more output going */
#if DEBUG
if (debug & DEBUG_ADDRESSES)
printf(" %s dev 0x%x, sd %d, offset 0x%x, devoffset 0x%x, length %ld\n",
sbp->b.b_flags & B_READ ? "Read" : "Write",
sbp->b.b_dev,
sbp->sdno,
(u_int) (sbp->b.b_blkno - SD[sbp->sdno].driveoffset),
(int) sbp->b.b_blkno,
sbp->b.b_bcount); /* XXX */
if (debug & DEBUG_NUMOUTPUT)
printf(" vinumstart sd %d numoutput %ld\n",
sbp->sdno,
sbp->b.b_vp->v_numoutput);
#endif
s = splbio();
(*bdevsw[major(sbp->b.b_dev)]->d_strategy) (&sbp->b);
splx(s);
}
/* Simplified version of bounds_check_with_label
* Determine the size of the transfer, and make sure it is
* within the boundaries of the partition. Adjust transfer
* if needed, and signal errors or early completion.
*
* Volumes are simpler than disk slices: they only contain
* one component (though we call them a, b and c to make
* system utilities happy), and they always take up the
* complete space of the "partition".
*
* I'm still not happy with this: why should the label be
* protected? If it weren't so damned difficult to write
* one in the first pleace (because it's protected), it wouldn't
* be a problem.
*/
int
vinum_bounds_check(struct buf *bp, struct volume *vol)
{
int maxsize = vol->size; /* size of the partition (sectors) */
int size = (bp->b_bcount + DEV_BSIZE - 1) >> DEV_BSHIFT; /* size of this request (sectors) */
/* Would this transfer overwrite the disk label? */
if (bp->b_blkno <= LABELSECTOR /* starts before or at the label */
#if LABELSECTOR != 0
&& bp->b_blkno + size > LABELSECTOR /* and finishes after */
#endif
&& (!(vol->flags & VF_RAW)) /* and it's not raw */
&&major(bp->b_dev) == BDEV_MAJOR /* and it's the block device */
&& (bp->b_flags & B_READ) == 0 /* and it's a write */
&& (!vol->flags & (VF_WLABEL | VF_LABELLING))) { /* and we're not allowed to write the label */
bp->b_error = EROFS; /* read-only */
bp->b_flags |= B_ERROR;
return -1;
}
if (size == 0) /* no transfer specified, */
return 0; /* treat as EOF */
/* beyond partition? */
if (bp->b_blkno < 0 /* negative start */
|| bp->b_blkno + size > maxsize) { /* or goes beyond the end of the partition */
/* if exactly at end of disk, return an EOF */
if (bp->b_blkno == maxsize) {
bp->b_resid = bp->b_bcount;
return 0;
}
/* or truncate if part of it fits */
size = maxsize - bp->b_blkno;
if (size <= 0) { /* nothing to transfer */
bp->b_error = EINVAL;
bp->b_flags |= B_ERROR;
return -1;
}
bp->b_bcount = size << DEV_BSHIFT;
}
bp->b_pblkno = bp->b_blkno;
return 1;
}
/* Allocate a request group and hook
* it in in the list for rq */
struct rqgroup *
allocrqg(struct request *rq, int elements)
{
struct rqgroup *rqg; /* the one we're going to allocate */
int size = sizeof(struct rqgroup) + elements * sizeof(struct rqelement);
rqg = (struct rqgroup *) Malloc(size);
if (rqg != NULL) { /* malloc OK, */
if (rq->rqg) /* we already have requests */
rq->lrqg->next = rqg; /* hang it off the end */
else /* first request */
rq->rqg = rqg; /* at the start */
rq->lrqg = rqg; /* this one is the last in the list */
bzero(rqg, size); /* no old junk */
rqg->rq = rq; /* point back to the parent request */
rqg->count = elements; /* number of requests in the group */
} else
Debugger("XXX");
return rqg;
}
/* Deallocate a request group out of a chain. We do
* this by linear search: the chain is short, this
* almost never happens, and currently it can only
* happen to the first member of the chain. */
void
deallocrqg(struct rqgroup *rqg)
{
struct rqgroup *rqgc = rqg->rq->rqg; /* point to the request chain */
if (rqg->rq->rqg == rqg) /* we're first in line */
rqg->rq->rqg = rqg->next; /* unhook ourselves */
else {
while (rqgc->next != rqg) /* find the group */
rqgc = rqgc->next;
rqgc->next = rqg->next;
}
Free(rqgc);
}
/* Character device interface */
int
vinumread(dev_t dev, struct uio *uio, int ioflag)
{
return (physio(vinumstrategy, NULL, dev, 1, minphys, uio));
}
int
vinumwrite(dev_t dev, struct uio *uio, int ioflag)
{
return (physio(vinumstrategy, NULL, dev, 0, minphys, uio));
}
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