/* $NetBSD: buf.c,v 1.12 2004/06/20 22:20:18 jmc 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. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include "makefs.h" #include #include #include "ffs/buf.h" #include "ffs/ufs_inode.h" extern int sectorsize; /* XXX: from ffs.c & mkfs.c */ TAILQ_HEAD(buftailhead,buf) buftail; int bread(int fd, struct fs *fs, daddr_t blkno, int size, struct buf **bpp) { off_t offset; ssize_t rv; assert (fs != NULL); assert (bpp != NULL); if (debug & DEBUG_BUF_BREAD) printf("bread: fs %p blkno %lld size %d\n", fs, (long long)blkno, size); *bpp = getblk(fd, fs, blkno, size); offset = (*bpp)->b_blkno * sectorsize; /* XXX */ if (debug & DEBUG_BUF_BREAD) printf("bread: bp %p blkno %lld offset %lld bcount %ld\n", (*bpp), (long long)(*bpp)->b_blkno, (long long) offset, (*bpp)->b_bcount); if (lseek((*bpp)->b_fd, offset, SEEK_SET) == -1) err(1, "bread: lseek %lld (%lld)", (long long)(*bpp)->b_blkno, (long long)offset); rv = read((*bpp)->b_fd, (*bpp)->b_data, (*bpp)->b_bcount); if (debug & DEBUG_BUF_BREAD) printf("bread: read %ld (%lld) returned %d\n", (*bpp)->b_bcount, (long long)offset, (int)rv); if (rv == -1) /* read error */ err(1, "bread: read %ld (%lld) returned %d", (*bpp)->b_bcount, (long long)offset, (int)rv); else if (rv != (*bpp)->b_bcount) /* short read */ err(1, "bread: read %ld (%lld) returned %d", (*bpp)->b_bcount, (long long)offset, (int)rv); else return (0); } void brelse(struct buf *bp) { 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; assert (bp != NULL); offset = bp->b_blkno * sectorsize; /* XXX */ if (debug & DEBUG_BUF_BWRITE) printf("bwrite: bp %p blkno %lld offset %lld bcount %ld\n", bp, (long long)bp->b_blkno, (long long) offset, bp->b_bcount); if (lseek(bp->b_fd, offset, SEEK_SET) == -1) return (errno); rv = write(bp->b_fd, bp->b_data, bp->b_bcount); if (debug & DEBUG_BUF_BWRITE) printf("bwrite: write %ld (offset %lld) returned %lld\n", bp->b_bcount, (long long)offset, (long long)rv); if (rv == bp->b_bcount) 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(int fd, struct fs *fs, daddr_t blkno, int size) { static int buftailinitted; struct buf *bp; void *n; assert (fs != NULL); if (debug & DEBUG_BUF_GETBLK) printf("getblk: fs %p blkno %lld size %d\n", fs, (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) { if ((bp = calloc(1, sizeof(struct buf))) == NULL) err(1, "getblk: calloc"); bp->b_bufsize = 0; bp->b_blkno = bp->b_lblkno = blkno; bp->b_fd = fd; bp->b_fs = 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 = realloc(bp->b_data, size); if (n == NULL) err(1, "getblk: realloc b_data %ld", bp->b_bcount); bp->b_data = n; bp->b_bufsize = size; } return (bp); }