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2e387f1bd3
with more than one plex, the data will be accessed
multiple times. During this time, userland code could
potentially modify the buffer, thus causing data
corruption. In the case of a multi-plexed volume this
might be cosmetic, but in the case of a RAID-[45] plex it
can cause severe data corruption which only becomes
evident after a drive failure. Avoid this situation by
making a copy of the data buffer before using it.
Note that this solution does not guarantee any particular
content of the buffer, just that it remains unchanged for
the duration of the request.
Suggested by: alfred
1106 lines
38 KiB
C
1106 lines
38 KiB
C
/*-
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* Copyright (c) 1997, 1998, 1999
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* Nan Yang Computer Services Limited. All rights reserved.
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*
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* Parts copyright (c) 1997, 1998 Cybernet Corporation, NetMAX project.
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*
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* Written by Greg Lehey
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*
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* This software is distributed under the so-called ``Berkeley
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* License'':
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by Nan Yang Computer
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* Services Limited.
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* 4. Neither the name of the Company nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* This software is provided ``as is'', and any express or implied
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* warranties, including, but not limited to, the implied warranties of
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* merchantability and fitness for a particular purpose are disclaimed.
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* In no event shall the company or contributors be liable for any
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* direct, indirect, incidental, special, exemplary, or consequential
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* damages (including, but not limited to, procurement of substitute
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* goods or services; loss of use, data, or profits; or business
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* interruption) however caused and on any theory of liability, whether
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* in contract, strict liability, or tort (including negligence or
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* otherwise) arising in any way out of the use of this software, even if
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* advised of the possibility of such damage.
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*
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* $Id: vinumrequest.c,v 1.30 2001/01/09 04:20:55 grog Exp grog $
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* $FreeBSD$
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*/
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#include <dev/vinum/vinumhdr.h>
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#include <dev/vinum/request.h>
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#include <sys/resourcevar.h>
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enum requeststatus bre(struct request *rq,
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int plexno,
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daddr_t * diskstart,
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daddr_t diskend);
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enum requeststatus bre5(struct request *rq,
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int plexno,
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daddr_t * diskstart,
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daddr_t diskend);
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enum requeststatus build_read_request(struct request *rq, int volplexno);
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enum requeststatus build_write_request(struct request *rq);
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enum requeststatus build_rq_buffer(struct rqelement *rqe, struct plex *plex);
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int find_alternate_sd(struct request *rq);
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int check_range_covered(struct request *);
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void complete_rqe(struct buf *bp);
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void complete_raid5_write(struct rqelement *);
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int abortrequest(struct request *rq, int error);
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void sdio_done(struct buf *bp);
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int vinum_bounds_check(struct buf *bp, struct volume *vol);
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caddr_t allocdatabuf(struct rqelement *rqe);
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void freedatabuf(struct rqelement *rqe);
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#ifdef VINUMDEBUG
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struct rqinfo rqinfo[RQINFO_SIZE];
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struct rqinfo *rqip = rqinfo;
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void
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logrq(enum rqinfo_type type, union rqinfou info, struct buf *ubp)
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{
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int s = splhigh();
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microtime(&rqip->timestamp); /* when did this happen? */
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rqip->type = type;
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rqip->bp = ubp; /* user buffer */
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switch (type) {
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case loginfo_user_bp:
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case loginfo_user_bpl:
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case loginfo_sdio: /* subdisk I/O */
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case loginfo_sdiol: /* subdisk I/O launch */
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case loginfo_sdiodone: /* subdisk I/O complete */
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bcopy(info.bp, &rqip->info.b, sizeof(struct buf));
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rqip->devmajor = major(info.bp->b_dev);
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rqip->devminor = minor(info.bp->b_dev);
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break;
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case loginfo_iodone:
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case loginfo_rqe:
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case loginfo_raid5_data:
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case loginfo_raid5_parity:
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bcopy(info.rqe, &rqip->info.rqe, sizeof(struct rqelement));
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rqip->devmajor = major(info.rqe->b.b_dev);
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rqip->devminor = minor(info.rqe->b.b_dev);
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break;
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case loginfo_lockwait:
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case loginfo_lock:
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case loginfo_unlock:
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bcopy(info.lockinfo, &rqip->info.lockinfo, sizeof(struct rangelock));
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break;
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case loginfo_unused:
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break;
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}
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rqip++;
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if (rqip >= &rqinfo[RQINFO_SIZE]) /* wrap around */
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rqip = rqinfo;
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splx(s);
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}
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#endif
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void
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vinumstrategy(struct bio *biop)
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{
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struct buf *bp = (struct buf *) biop;
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int volno;
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struct volume *vol = NULL;
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switch (DEVTYPE(bp->b_dev)) {
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case VINUM_SD_TYPE:
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case VINUM_RAWSD_TYPE:
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sdio(bp);
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return;
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/*
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* In fact, vinum doesn't handle drives: they're
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* handled directly by the disk drivers
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*/
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case VINUM_DRIVE_TYPE:
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default:
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bp->b_error = EIO; /* I/O error */
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bp->b_io.bio_flags |= BIO_ERROR;
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bufdone(bp);
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return;
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case VINUM_VOLUME_TYPE: /* volume I/O */
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volno = Volno(bp->b_dev);
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vol = &VOL[volno];
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if (vol->state != volume_up) { /* can't access this volume */
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bp->b_error = EIO; /* I/O error */
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bp->b_io.bio_flags |= BIO_ERROR;
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bufdone(bp);
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return;
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}
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if (vinum_bounds_check(bp, vol) <= 0) { /* don't like them bounds */
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bufdone(bp);
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return;
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}
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/* FALLTHROUGH */
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/*
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* Plex I/O is pretty much the same as volume I/O
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* for a single plex. Indicate this by passing a NULL
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* pointer (set above) for the volume
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*/
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case VINUM_PLEX_TYPE:
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case VINUM_RAWPLEX_TYPE:
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bp->b_resid = bp->b_bcount; /* transfer everything */
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vinumstart(bp, 0);
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return;
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}
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}
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/*
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* Start a transfer. Return -1 on error, 0 if OK,
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* 1 if we need to retry. Parameter reviveok is
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* set when doing transfers for revives: it allows
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* transfers to be started immediately when a
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* revive is in progress. During revive, normal
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* transfers are queued if they share address
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* space with a currently active revive operation.
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*/
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int
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vinumstart(struct buf *bp, int reviveok)
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{
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int plexno;
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int maxplex; /* maximum number of plexes to handle */
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struct volume *vol;
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struct request *rq; /* build up our request here */
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enum requeststatus status;
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#if VINUMDEBUG
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if (debug & DEBUG_LASTREQS)
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logrq(loginfo_user_bp, (union rqinfou) bp, bp);
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#endif
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if ((bp->b_bcount % DEV_BSIZE) != 0) { /* bad length */
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bp->b_error = EINVAL; /* invalid size */
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bp->b_io.bio_flags |= BIO_ERROR;
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bufdone(bp);
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return -1;
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}
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rq = (struct request *) Malloc(sizeof(struct request)); /* allocate a request struct */
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if (rq == NULL) { /* can't do it */
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bp->b_error = ENOMEM; /* can't get memory */
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bp->b_io.bio_flags |= BIO_ERROR;
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bufdone(bp);
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return -1;
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}
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bzero(rq, sizeof(struct request));
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/*
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* Note the volume ID. This can be NULL, which
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* the request building functions use as an
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* indication for single plex I/O.
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*/
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rq->bp = bp; /* and the user buffer struct */
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if (DEVTYPE(bp->b_dev) == VINUM_VOLUME_TYPE) { /* it's a volume, */
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rq->volplex.volno = Volno(bp->b_dev); /* get the volume number */
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vol = &VOL[rq->volplex.volno]; /* and point to it */
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vol->active++; /* one more active request */
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maxplex = vol->plexes; /* consider all its plexes */
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} else {
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vol = NULL; /* no volume */
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rq->volplex.plexno = Plexno(bp->b_dev); /* point to the plex */
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rq->isplex = 1; /* note that it's a plex */
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maxplex = 1; /* just the one plex */
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}
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if (bp->b_iocmd == BIO_READ) {
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/*
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* This is a read request. Decide
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* which plex to read from.
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*
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* There's a potential race condition here,
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* since we're not locked, and we could end
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* up multiply incrementing the round-robin
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* counter. This doesn't have any serious
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* effects, however.
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*/
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if (vol != NULL) {
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plexno = vol->preferred_plex; /* get the plex to use */
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if (plexno < 0) { /* round robin */
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plexno = vol->last_plex_read;
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vol->last_plex_read++;
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if (vol->last_plex_read >= vol->plexes) /* got the the end? */
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vol->last_plex_read = 0; /* wrap around */
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}
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status = build_read_request(rq, plexno); /* build a request */
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} else {
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daddr_t diskaddr = bp->b_blkno; /* start offset of transfer */
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status = bre(rq, /* build a request list */
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rq->volplex.plexno,
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&diskaddr,
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diskaddr + (bp->b_bcount / DEV_BSIZE));
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}
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if (status > REQUEST_RECOVERED) { /* can't satisfy it */
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if (status == REQUEST_DOWN) { /* not enough subdisks */
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bp->b_error = EIO; /* I/O error */
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bp->b_io.bio_flags |= BIO_ERROR;
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}
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bufdone(bp);
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freerq(rq);
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return -1;
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}
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return launch_requests(rq, reviveok); /* now start the requests if we can */
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} else
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/*
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* This is a write operation. We write to all plexes. If this is
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* a RAID-4 or RAID-5 plex, we must also update the parity stripe.
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*/
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{
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if (vol != NULL) {
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if ((vol->plexes > 0) /* multiple plex */
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||(isparity((&PLEX[vol->plex[0]])))) { /* or RAID-[45], */
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rq->save_data = bp->b_data; /* save the data buffer address */
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bp->b_data = Malloc(bp->b_bufsize);
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bcopy(rq->save_data, bp->b_data, bp->b_bufsize); /* make a copy */
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rq->flags |= XFR_COPYBUF; /* and note that we did it */
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}
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status = build_write_request(rq);
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} else { /* plex I/O */
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daddr_t diskstart;
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diskstart = bp->b_blkno; /* start offset of transfer */
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status = bre(rq,
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Plexno(bp->b_dev),
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&diskstart,
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bp->b_blkno + (bp->b_bcount / DEV_BSIZE)); /* build requests for the plex */
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}
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if (status > REQUEST_RECOVERED) { /* can't satisfy it */
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if (status == REQUEST_DOWN) { /* not enough subdisks */
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bp->b_error = EIO; /* I/O error */
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bp->b_io.bio_flags |= BIO_ERROR;
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}
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if (rq->flags & XFR_COPYBUF) {
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Free(bp->b_data);
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bp->b_data = rq->save_data;
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}
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bufdone(bp);
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freerq(rq);
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return -1;
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}
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return launch_requests(rq, reviveok); /* now start the requests if we can */
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}
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}
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/*
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* Call the low-level strategy routines to
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* perform the requests in a struct request
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*/
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int
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launch_requests(struct request *rq, int reviveok)
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{
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struct rqgroup *rqg;
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int rqno; /* loop index */
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struct rqelement *rqe; /* current element */
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struct drive *drive;
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int rcount; /* request count */
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/*
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* First find out whether we're reviving, and the
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* request contains a conflict. If so, we hang
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* the request off plex->waitlist of the first
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* plex we find which is reviving
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*/
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if ((rq->flags & XFR_REVIVECONFLICT) /* possible revive conflict */
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&&(!reviveok)) { /* and we don't want to do it now, */
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struct sd *sd;
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struct request *waitlist; /* point to the waitlist */
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sd = &SD[rq->sdno];
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if (sd->waitlist != NULL) { /* something there already, */
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waitlist = sd->waitlist;
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while (waitlist->next != NULL) /* find the end */
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waitlist = waitlist->next;
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waitlist->next = rq; /* hook our request there */
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} else
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sd->waitlist = rq; /* hook our request at the front */
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#if VINUMDEBUG
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if (debug & DEBUG_REVIVECONFLICT)
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log(LOG_DEBUG,
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"Revive conflict sd %d: %p\n%s dev %d.%d, offset 0x%x, length %ld\n",
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rq->sdno,
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rq,
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rq->bp->b_iocmd == BIO_READ ? "Read" : "Write",
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major(rq->bp->b_dev),
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minor(rq->bp->b_dev),
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rq->bp->b_blkno,
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rq->bp->b_bcount);
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#endif
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return 0; /* and get out of here */
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}
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rq->active = 0; /* nothing yet */
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#if VINUMDEBUG
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if (debug & DEBUG_ADDRESSES)
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log(LOG_DEBUG,
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"Request: %p\n%s dev %d.%d, offset 0x%x, length %ld\n",
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rq,
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rq->bp->b_iocmd == BIO_READ ? "Read" : "Write",
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major(rq->bp->b_dev),
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minor(rq->bp->b_dev),
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rq->bp->b_blkno,
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rq->bp->b_bcount);
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vinum_conf.lastrq = rq;
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vinum_conf.lastbuf = rq->bp;
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if (debug & DEBUG_LASTREQS)
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logrq(loginfo_user_bpl, (union rqinfou) rq->bp, rq->bp);
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#endif
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/*
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* We used to have an splbio() here anyway, out
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* of superstition. With the division of labour
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* below (first count the requests, then issue
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* them), it looks as if we don't need this
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* splbio() protection. In fact, as dillon
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* points out, there's a race condition
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* incrementing and decrementing rq->active and
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* rqg->active. This splbio() didn't help
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* there, because the device strategy routine
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* can sleep. Solve this by putting shorter
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* duration locks on the code.
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*/
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/*
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* This loop happens without any participation
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* of the bottom half, so it requires no
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* protection.
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*/
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for (rqg = rq->rqg; rqg != NULL; rqg = rqg->next) { /* through the whole request chain */
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rqg->active = rqg->count; /* they're all active */
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for (rqno = 0; rqno < rqg->count; rqno++) {
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rqe = &rqg->rqe[rqno];
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if (rqe->flags & XFR_BAD_SUBDISK) /* this subdisk is bad, */
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rqg->active--; /* one less active request */
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}
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if (rqg->active) /* we have at least one active request, */
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rq->active++; /* one more active request group */
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}
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/*
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* Now fire off the requests. In this loop the
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|
* bottom half could be completing requests
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* before we finish, so we need splbio() protection.
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*/
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for (rqg = rq->rqg; rqg != NULL;) { /* through the whole request chain */
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if (rqg->lockbase >= 0) /* this rqg needs a lock first */
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rqg->lock = lockrange(rqg->lockbase, rqg->rq->bp, &PLEX[rqg->plexno]);
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rcount = rqg->count;
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for (rqno = 0; rqno < rcount;) {
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rqe = &rqg->rqe[rqno];
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|
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/*
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|
* Point to next rqg before the bottom end
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|
* changes the structures.
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|
*/
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if (++rqno >= rcount)
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rqg = rqg->next;
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if ((rqe->flags & XFR_BAD_SUBDISK) == 0) { /* this subdisk is good, */
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drive = &DRIVE[rqe->driveno]; /* look at drive */
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drive->active++;
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if (drive->active >= drive->maxactive)
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drive->maxactive = drive->active;
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vinum_conf.active++;
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if (vinum_conf.active >= vinum_conf.maxactive)
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vinum_conf.maxactive = vinum_conf.active;
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|
|
|
#ifdef VINUMDEBUG
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if (debug & DEBUG_ADDRESSES)
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log(LOG_DEBUG,
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" %s dev %d.%d, sd %d, offset 0x%x, devoffset 0x%x, length %ld\n",
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rqe->b.b_iocmd == BIO_READ ? "Read" : "Write",
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major(rqe->b.b_dev),
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|
minor(rqe->b.b_dev),
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rqe->sdno,
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(u_int) (rqe->b.b_blkno - SD[rqe->sdno].driveoffset),
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|
rqe->b.b_blkno,
|
|
rqe->b.b_bcount);
|
|
if (debug & DEBUG_LASTREQS)
|
|
logrq(loginfo_rqe, (union rqinfou) rqe, rq->bp);
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#endif
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/* fire off the request */
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DEV_STRATEGY(&rqe->b, 0);
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}
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|
}
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|
}
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|
return 0;
|
|
}
|
|
|
|
/*
|
|
* define the low-level requests needed to perform a
|
|
* high-level I/O operation for a specific plex 'plexno'.
|
|
*
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|
* Return REQUEST_OK if all subdisks involved in the request are up,
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|
* REQUEST_DOWN if some subdisks are not up, and REQUEST_EOF if the
|
|
* request is at least partially outside the bounds of the subdisks.
|
|
*
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|
* Modify the pointer *diskstart to point to the end address. On
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|
* read, return on the first bad subdisk, so that the caller
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|
* (build_read_request) can try alternatives.
|
|
*
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|
* On entry to this routine, the rqg structures are not assigned. The
|
|
* assignment is performed by expandrq(). Strictly speaking, the
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|
* elements rqe->sdno of all entries should be set to -1, since 0
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|
* (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)
|
|
{
|
|
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 */
|
|
enum requeststatus s; /* temp return value */
|
|
|
|
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:
|
|
sd = NULL; /* (keep compiler quiet) */
|
|
for (sdno = 0; sdno < plex->subdisks; sdno++) {
|
|
sd = &SD[plex->sdnos[sdno]];
|
|
if (*diskaddr < sd->plexoffset) /* we must have a hole, */
|
|
status = REQUEST_DEGRADED; /* note the fact */
|
|
if (*diskaddr < (sd->plexoffset + sd->sectors)) { /* the request starts in this subdisk */
|
|
rqg = allocrqg(rq, 1); /* space for the request */
|
|
if (rqg == NULL) { /* malloc failed */
|
|
bp->b_error = ENOMEM;
|
|
bp->b_io.bio_flags |= BIO_ERROR;
|
|
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 = *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;
|
|
if (sd->state != sd_up) { /* *now* we find the sd is down */
|
|
s = checksdstate(sd, rq, *diskaddr, diskend); /* do we need to change state? */
|
|
if (s == REQUEST_DOWN) { /* down? */
|
|
rqe->flags = XFR_BAD_SUBDISK; /* yup */
|
|
if (rq->bp->b_iocmd == BIO_READ) /* read request, */
|
|
return REQUEST_DEGRADED; /* give up here */
|
|
/*
|
|
* If we're writing, don't give up
|
|
* because of a bad subdisk. Go
|
|
* through to the bitter end, but note
|
|
* which ones we can't access.
|
|
*/
|
|
status = REQUEST_DEGRADED; /* can't do it all */
|
|
}
|
|
}
|
|
*diskaddr += rqe->datalen; /* bump the address */
|
|
if (build_rq_buffer(rqe, plex)) { /* build the buffer */
|
|
deallocrqg(rqg);
|
|
bp->b_error = ENOMEM;
|
|
bp->b_io.bio_flags |= BIO_ERROR;
|
|
return REQUEST_ENOMEM; /* can't do it */
|
|
}
|
|
}
|
|
if (*diskaddr == diskend) /* we're finished, */
|
|
break; /* get out of here */
|
|
}
|
|
/*
|
|
* We've got to the end of the plex. Have we got to the end of
|
|
* the transfer? It would seem that having an offset beyond the
|
|
* end of the subdisk is an error, but in fact it can happen if
|
|
* the volume has another plex of different size. There's a valid
|
|
* question as to why you would want to do this, but currently
|
|
* it's allowed.
|
|
*
|
|
* In a previous version, I returned REQUEST_DOWN here. I think
|
|
* REQUEST_EOF is more appropriate now.
|
|
*/
|
|
if (diskend > sd->sectors + sd->plexoffset) /* pointing beyond EOF? */
|
|
status = REQUEST_EOF;
|
|
break;
|
|
|
|
case plex_striped:
|
|
{
|
|
while (*diskaddr < diskend) { /* until we get it all sorted out */
|
|
if (*diskaddr >= plex->length) /* beyond the end of the plex */
|
|
return REQUEST_EOF; /* can't continue */
|
|
|
|
/* 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 */
|
|
rqg = allocrqg(rq, 1); /* space for the request */
|
|
if (rqg == NULL) { /* malloc failed */
|
|
bp->b_error = ENOMEM;
|
|
bp->b_io.bio_flags |= BIO_ERROR;
|
|
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 (sd->state != sd_up) { /* *now* we find the sd is down */
|
|
s = checksdstate(sd, rq, *diskaddr, diskend); /* do we need to change state? */
|
|
if (s == REQUEST_DOWN) { /* down? */
|
|
rqe->flags = XFR_BAD_SUBDISK; /* yup */
|
|
if (rq->bp->b_iocmd == BIO_READ) /* read request, */
|
|
return REQUEST_DEGRADED; /* give up here */
|
|
/*
|
|
* If we're writing, don't give up
|
|
* because of a bad subdisk. Go through
|
|
* to the bitter end, but note which
|
|
* ones we can't access.
|
|
*/
|
|
status = REQUEST_DEGRADED; /* can't do it all */
|
|
}
|
|
}
|
|
/*
|
|
* It would seem that having an offset
|
|
* beyond the end of the subdisk is an
|
|
* error, but in fact it can happen if the
|
|
* volume has another plex of different
|
|
* size. There's a valid question as to why
|
|
* you would want to do this, but currently
|
|
* it's allowed.
|
|
*/
|
|
if (rqe->sdoffset + rqe->datalen > sd->sectors) { /* ends beyond the end of the subdisk? */
|
|
rqe->datalen = sd->sectors - rqe->sdoffset; /* truncate */
|
|
#if VINUMDEBUG
|
|
if (debug & DEBUG_EOFINFO) { /* tell on the request */
|
|
log(LOG_DEBUG,
|
|
"vinum: EOF on plex %s, sd %s offset %x (user offset %x)\n",
|
|
plex->name,
|
|
sd->name,
|
|
(u_int) sd->sectors,
|
|
bp->b_blkno);
|
|
log(LOG_DEBUG,
|
|
"vinum: stripebase %x, stripeoffset %x, blockoffset %x\n",
|
|
stripebase,
|
|
stripeoffset,
|
|
blockoffset);
|
|
}
|
|
#endif
|
|
}
|
|
if (build_rq_buffer(rqe, plex)) { /* build the buffer */
|
|
deallocrqg(rqg);
|
|
bp->b_error = ENOMEM;
|
|
bp->b_io.bio_flags |= BIO_ERROR;
|
|
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 */
|
|
&&(*diskaddr < plex->length)) { /* and there's more to come */
|
|
plex->multiblock++; /* count another one */
|
|
if (sdno == plex->subdisks - 1) /* last subdisk, */
|
|
plex->multistripe++; /* another stripe as well */
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
|
|
/*
|
|
* RAID-4 and RAID-5 are complicated enough to have their own
|
|
* function.
|
|
*/
|
|
case plex_raid4:
|
|
case plex_raid5:
|
|
status = bre5(rq, plexno, diskaddr, diskend);
|
|
break;
|
|
|
|
default:
|
|
log(LOG_ERR, "vinum: invalid plex type %d in bre\n", plex->organization);
|
|
status = REQUEST_DOWN; /* can't access it */
|
|
}
|
|
|
|
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 */
|
|
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 */
|
|
int recovered = 0; /* set if we recover a read */
|
|
enum requeststatus status = REQUEST_OK;
|
|
int plexmask; /* bit mask of plexes, for recovery */
|
|
|
|
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:
|
|
/*
|
|
* XXX FIXME if we have more than one plex, and we can
|
|
* satisfy the request from another, don't use the
|
|
* recovered request, since it's more expensive.
|
|
*/
|
|
recovered = 1;
|
|
break;
|
|
|
|
case REQUEST_ENOMEM:
|
|
return status;
|
|
/*
|
|
* If we get here, our request is not complete. Try
|
|
* to fill in the missing parts from another plex.
|
|
* This can happen multiple times in this function,
|
|
* and we reinitialize the plex mask each time, since
|
|
* we could have a hole in our plexes.
|
|
*/
|
|
case REQUEST_EOF:
|
|
case REQUEST_DOWN: /* can't access the plex */
|
|
case REQUEST_DEGRADED: /* can't access the plex */
|
|
plexmask = ((1 << vol->plexes) - 1) /* all plexes in the volume */
|
|
&~(1 << plexindex); /* except for the one we were looking at */
|
|
for (plexno = 0; plexno < vol->plexes; plexno++) {
|
|
if (plexmask == 0) /* no plexes left to try */
|
|
return REQUEST_DOWN; /* failed */
|
|
diskaddr = startaddr; /* start at the beginning again */
|
|
if (plexmask & (1 << plexno)) { /* we haven't tried this plex yet */
|
|
bre(rq, vol->plex[plexno], &diskaddr, diskend); /* try a request */
|
|
if (diskaddr > startaddr) { /* we satisfied another part */
|
|
recovered = 1; /* we recovered from the problem */
|
|
status = REQUEST_OK; /* don't complain about it */
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (diskaddr == startaddr) /* didn't get any further, */
|
|
return status;
|
|
}
|
|
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 */
|
|
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_DOWN; /* assume the worst */
|
|
for (plexno = 0; plexno < vol->plexes; plexno++) {
|
|
diskstart = bp->b_blkno; /* start offset of transfer */
|
|
/*
|
|
* Build requests for the plex.
|
|
* We take the best possible result here (min,
|
|
* not max): we're happy if we can write at all
|
|
*/
|
|
status = min(status, bre(rq,
|
|
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)
|
|
{
|
|
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 */
|
|
/* copy these flags from user bp */
|
|
bp->b_flags = ubp->b_flags & (B_NOCACHE | B_ASYNC);
|
|
bp->b_io.bio_flags = ubp->b_io.bio_flags & BIO_ORDERED;
|
|
bp->b_iocmd = ubp->b_iocmd;
|
|
#ifdef VINUMDEBUG
|
|
if (rqe->flags & XFR_BUFLOCKED) /* paranoia */
|
|
panic("build_rq_buffer: rqe already locked"); /* XXX remove this when we're sure */
|
|
#endif
|
|
BUF_LOCKINIT(bp); /* get a lock for the buffer */
|
|
BUF_LOCK(bp, LK_EXCLUSIVE); /* and lock it */
|
|
BUF_KERNPROC(bp);
|
|
rqe->flags |= XFR_BUFLOCKED;
|
|
bp->b_iodone = complete_rqe;
|
|
/*
|
|
* You'd think that we wouldn't need to even
|
|
* build the request buffer for a dead subdisk,
|
|
* but in some cases we need information like
|
|
* the user buffer address. Err on the side of
|
|
* generosity and supply what we can. That
|
|
* obviously doesn't include drive information
|
|
* when the drive is dead.
|
|
*/
|
|
if ((rqe->flags & XFR_BAD_SUBDISK) == 0) /* subdisk is accessible, */
|
|
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_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 */
|
|
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;
|
|
/*
|
|
* On a recovery read, we perform an XOR of
|
|
* all blocks to the user buffer. To make
|
|
* this work, we first clean out the buffer
|
|
*/
|
|
if ((rqe->flags & (XFR_RECOVERY_READ | XFR_BAD_SUBDISK))
|
|
== (XFR_RECOVERY_READ | XFR_BAD_SUBDISK)) { /* bad subdisk of a recovery read */
|
|
int length = rqe->grouplen << DEV_BSHIFT; /* and count involved */
|
|
char *data = (char *) &rqe->b.b_data[rqe->groupoffset << DEV_BSHIFT]; /* destination */
|
|
|
|
bzero(data, length); /* clean it out */
|
|
}
|
|
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_error = error;
|
|
freerq(rq); /* free everything we're doing */
|
|
bp->b_io.bio_flags |= BIO_ERROR;
|
|
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)
|
|
{
|
|
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;
|
|
|
|
#if VINUMDEBUG
|
|
if (debug & DEBUG_LASTREQS)
|
|
logrq(loginfo_sdio, (union rqinfou) bp, bp);
|
|
#endif
|
|
sd = &SD[Sdno(bp->b_dev)]; /* point to the subdisk */
|
|
drive = &DRIVE[sd->driveno];
|
|
|
|
if (drive->state != drive_up) {
|
|
if (sd->state >= sd_crashed) {
|
|
if (bp->b_iocmd == BIO_WRITE) /* writing, */
|
|
set_sd_state(sd->sdno, sd_stale, setstate_force);
|
|
else
|
|
set_sd_state(sd->sdno, sd_crashed, setstate_force);
|
|
}
|
|
bp->b_error = EIO;
|
|
bp->b_io.bio_flags |= BIO_ERROR;
|
|
bufdone(bp);
|
|
return;
|
|
}
|
|
/*
|
|
* We allow access to any kind of subdisk as long as we can expect
|
|
* to get the I/O performed.
|
|
*/
|
|
if (sd->state < sd_empty) { /* nothing to talk to, */
|
|
bp->b_error = EIO;
|
|
bp->b_io.bio_flags |= BIO_ERROR;
|
|
bufdone(bp);
|
|
return;
|
|
}
|
|
/* Get a buffer */
|
|
sbp = (struct sdbuf *) Malloc(sizeof(struct sdbuf));
|
|
if (sbp == NULL) {
|
|
bp->b_error = ENOMEM;
|
|
bp->b_io.bio_flags |= BIO_ERROR;
|
|
bufdone(bp);
|
|
return;
|
|
}
|
|
bzero(sbp, sizeof(struct sdbuf)); /* start with nothing */
|
|
sbp->b.b_flags = bp->b_flags;
|
|
sbp->b.b_iocmd = bp->b_iocmd;
|
|
sbp->b.b_bufsize = bp->b_bufsize; /* buffer size */
|
|
sbp->b.b_bcount = bp->b_bcount; /* number of bytes to transfer */
|
|
sbp->b.b_resid = bp->b_resid; /* and amount waiting */
|
|
sbp->b.b_dev = DRIVE[sd->driveno].dev; /* device */
|
|
sbp->b.b_data = bp->b_data; /* data buffer */
|
|
sbp->b.b_blkno = bp->b_blkno + sd->driveoffset;
|
|
sbp->b.b_iodone = sdio_done; /* come here on completion */
|
|
BUF_LOCKINIT(&sbp->b); /* get a lock for the buffer */
|
|
BUF_LOCK(&sbp->b, LK_EXCLUSIVE); /* and lock it */
|
|
BUF_KERNPROC(&sbp->b);
|
|
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 */
|
|
bufdone(bp);
|
|
BUF_UNLOCK(&sbp->b);
|
|
BUF_LOCKFREE(&sbp->b);
|
|
Free(sbp);
|
|
return;
|
|
}
|
|
}
|
|
#if VINUMDEBUG
|
|
if (debug & DEBUG_ADDRESSES)
|
|
log(LOG_DEBUG,
|
|
" %s dev %d.%d, sd %d, offset 0x%x, devoffset 0x%x, length %ld\n",
|
|
sbp->b.b_iocmd == BIO_READ ? "Read" : "Write",
|
|
major(sbp->b.b_dev),
|
|
minor(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);
|
|
#endif
|
|
s = splbio();
|
|
#if VINUMDEBUG
|
|
if (debug & DEBUG_LASTREQS)
|
|
logrq(loginfo_sdiol, (union rqinfou) &sbp->b, &sbp->b);
|
|
#endif
|
|
DEV_STRATEGY(&sbp->b, 0);
|
|
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 */
|
|
&&(bp->b_iocmd == BIO_WRITE) /* 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_io.bio_flags |= BIO_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_io.bio_flags |= BIO_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 */
|
|
}
|
|
rqg->lockbase = -1; /* no lock required yet */
|
|
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->lock) /* got a lock? */
|
|
unlockrange(rqg->plexno, rqg->lock); /* yes, free it */
|
|
if (rqgc == rqg) /* we're first in line */
|
|
rqg->rq->rqg = rqg->next; /* unhook ourselves */
|
|
else {
|
|
while ((rqgc->next != NULL) /* find the group */
|
|
&&(rqgc->next != rqg))
|
|
rqgc = rqgc->next;
|
|
if (rqgc->next == NULL)
|
|
log(LOG_ERR,
|
|
"vinum deallocrqg: rqg %p not found in request %p\n",
|
|
rqg->rq,
|
|
rqg);
|
|
else
|
|
rqgc->next = rqg->next; /* make the chain jump over us */
|
|
}
|
|
Free(rqg);
|
|
}
|
|
|
|
/* Local Variables: */
|
|
/* fill-column: 50 */
|
|
/* End: */
|