/* $NetBSD: buf.c,v 1.24 2016/06/24 19:24:11 christos Exp $ */ /* * Copyright (c) 2001 Wasabi Systems, Inc. * All rights reserved. * * Written by Luke Mewburn for Wasabi Systems, Inc. * * 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 for the NetBSD Project by * Wasabi Systems, Inc. * 4. The name of Wasabi Systems, Inc. may not be used to endorse * or promote products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC * 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. */ #if HAVE_NBTOOL_CONFIG_H #include "nbtool_config.h" #endif #include #if defined(__RCSID) && !defined(__lint) __RCSID("$NetBSD: buf.c,v 1.24 2016/06/24 19:24:11 christos Exp $"); #endif /* !__lint */ #include #include #include #include #include #include #include #include #include "makefs.h" #include "buf.h" TAILQ_HEAD(buftailhead,buf) buftail; int bread(struct vnode *vp, daddr_t blkno, int size, int u2 __unused, struct buf **bpp) { off_t offset; ssize_t rv; fsinfo_t *fs = vp->fs; assert (bpp != NULL); if (debug & DEBUG_BUF_BREAD) printf("bread: blkno %lld size %d\n", (long long)blkno, size); *bpp = getblk(vp, blkno, size, 0, 0); offset = (*bpp)->b_blkno * fs->sectorsize + fs->offset; if (debug & DEBUG_BUF_BREAD) printf("bread: blkno %lld offset %lld bcount %ld\n", (long long)(*bpp)->b_blkno, (long long) offset, (*bpp)->b_bcount); if (lseek((*bpp)->b_fs->fd, offset, SEEK_SET) == -1) err(EXIT_FAILURE, "%s: lseek %lld (%lld)", __func__, (long long)(*bpp)->b_blkno, (long long)offset); rv = read((*bpp)->b_fs->fd, (*bpp)->b_data, (size_t)(*bpp)->b_bcount); if (debug & DEBUG_BUF_BREAD) printf("bread: read %ld (%lld) returned %zd\n", (*bpp)->b_bcount, (long long)offset, rv); if (rv == -1) /* read error */ err(EXIT_FAILURE, "%s: read %ld (%lld) returned %zd", __func__, (*bpp)->b_bcount, (long long)offset, rv); else if (rv != (*bpp)->b_bcount) /* short read */ errx(EXIT_FAILURE, "%s: read %ld (%lld) returned %zd", __func__, (*bpp)->b_bcount, (long long)offset, rv); else return (0); } void brelse(struct buf *bp, int u1 __unused) { assert (bp != NULL); assert (bp->b_data != NULL); if (bp->b_lblkno < 0) { /* * XXX don't remove any buffers with negative logical block * numbers (lblkno), so that we retain the mapping * of negative lblkno -> real blkno that ffs_balloc() * sets up. * * if we instead released these buffers, and implemented * ufs_strategy() (and ufs_bmaparray()) and called those * from bread() and bwrite() to convert the lblkno to * a real blkno, we'd add a lot more code & complexity * and reading off disk, for little gain, because this * simple hack works for our purpose. */ bp->b_bcount = 0; return; } TAILQ_REMOVE(&buftail, bp, b_tailq); free(bp->b_data); free(bp); } int bwrite(struct buf *bp) { off_t offset; ssize_t rv; size_t bytes; fsinfo_t *fs = bp->b_fs; assert (bp != NULL); offset = bp->b_blkno * fs->sectorsize + fs->offset; bytes = (size_t)bp->b_bcount; if (debug & DEBUG_BUF_BWRITE) printf("bwrite: blkno %lld offset %lld bcount %zu\n", (long long)bp->b_blkno, (long long) offset, bytes); if (lseek(bp->b_fs->fd, offset, SEEK_SET) == -1) return (errno); rv = write(bp->b_fs->fd, bp->b_data, bytes); if (debug & DEBUG_BUF_BWRITE) printf("bwrite: write %ld (offset %lld) returned %lld\n", bp->b_bcount, (long long)offset, (long long)rv); brelse(bp, 0); if (rv == (ssize_t)bytes) return (0); else if (rv == -1) /* write error */ return (errno); else /* short write ? */ return (EAGAIN); } void bcleanup(void) { struct buf *bp; /* * XXX this really shouldn't be necessary, but i'm curious to * know why there's still some buffers lying around that * aren't brelse()d */ if (TAILQ_EMPTY(&buftail)) return; printf("bcleanup: unflushed buffers:\n"); TAILQ_FOREACH(bp, &buftail, b_tailq) { printf("\tlblkno %10lld blkno %10lld count %6ld bufsize %6ld\n", (long long)bp->b_lblkno, (long long)bp->b_blkno, bp->b_bcount, bp->b_bufsize); } printf("bcleanup: done\n"); } struct buf * getblk(struct vnode *vp, daddr_t blkno, int size, int u1 __unused, int u2 __unused) { static int buftailinitted; struct buf *bp; void *n; if (debug & DEBUG_BUF_GETBLK) printf("getblk: blkno %lld size %d\n", (long long)blkno, size); bp = NULL; if (!buftailinitted) { if (debug & DEBUG_BUF_GETBLK) printf("getblk: initialising tailq\n"); TAILQ_INIT(&buftail); buftailinitted = 1; } else { TAILQ_FOREACH(bp, &buftail, b_tailq) { if (bp->b_lblkno != blkno) continue; break; } } if (bp == NULL) { bp = ecalloc(1, sizeof(*bp)); bp->b_bufsize = 0; bp->b_blkno = bp->b_lblkno = blkno; bp->b_fs = vp->fs; bp->b_data = NULL; TAILQ_INSERT_HEAD(&buftail, bp, b_tailq); } bp->b_bcount = size; if (bp->b_data == NULL || bp->b_bcount > bp->b_bufsize) { n = erealloc(bp->b_data, (size_t)size); memset(n, 0, (size_t)size); bp->b_data = n; bp->b_bufsize = size; } return (bp); }