From 7d924377ca9361970a3caeb914c5879b283220aa Mon Sep 17 00:00:00 2001
From: phk <phk@FreeBSD.org>
Date: Wed, 5 Jun 2002 11:10:38 +0000
Subject: Preparation for UFS2 commit:

Factor the ufs reading code out of the i386/boot2 loader so it can
be reused by for instance sparc64.

Sponsored by: DARPA and NAI Labs.
---
 sys/boot/common/ufsread.c | 183 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 183 insertions(+)
 create mode 100644 sys/boot/common/ufsread.c

(limited to 'sys/boot/common/ufsread.c')

diff --git a/sys/boot/common/ufsread.c b/sys/boot/common/ufsread.c
new file mode 100644
index 0000000..86655c7
--- /dev/null
+++ b/sys/boot/common/ufsread.c
@@ -0,0 +1,183 @@
+/*
+ * Copyright (c) 1998 Robert Nordier
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are freely
+ * permitted provided that the above copyright notice and this
+ * paragraph and the following disclaimer are duplicated in all
+ * such forms.
+ *
+ * This software is provided "AS IS" and without any express or
+ * implied warranties, including, without limitation, the implied
+ * warranties of merchantability and fitness for a particular
+ * purpose.
+ */
+
+/*
+ * $FreeBSD$
+ */
+
+#include <ufs/ffs/fs.h>
+#include <ufs/ufs/dinode.h>
+
+/*
+ * We use 4k `virtual' blocks for filesystem data, whatever the actual
+ * filesystem block size. FFS blocks are always a multiple of 4k.
+ */
+#define VBLKSIZE	4096
+#define VBLKMASK	(VBLKSIZE - 1)
+#define DBPERVBLK	(VBLKSIZE / DEV_BSIZE)
+#define IPERVBLK	(VBLKSIZE / sizeof(struct dinode))
+#define INDIRPERVBLK	(VBLKSIZE / sizeof(ufs_daddr_t))
+#define INO_TO_VBA(fs, x) (fsbtodb(fs, ino_to_fsba(fs, x)) + \
+    (ino_to_fsbo(fs, x) / IPERVBLK) * DBPERVBLK)
+#define INO_TO_VBO(fs, x) (ino_to_fsbo(fs, x) % IPERVBLK)
+#define FS_TO_VBA(fs, fsb, off) (fsbtodb(fs, fsb) + \
+    ((off) / VBLKSIZE) * DBPERVBLK)
+#define FS_TO_VBO(fs, fsb, off) ((off) & VBLKMASK)
+
+/* Buffers that must not span a 64k boundary. */
+static struct dmadat {
+	char blkbuf[VBLKSIZE];				/* filesystem blocks */
+	ufs_daddr_t indbuf[VBLKSIZE / sizeof(ufs_daddr_t)]; /* indir blocks */
+	char sbbuf[SBSIZE];				/* superblock */
+	char secbuf[DEV_BSIZE];				/* for MBR/disklabel */
+} *dmadat;
+
+static ino_t lookup(const char *);
+static ssize_t fsread(ino_t, void *, size_t);
+
+static int ls, dsk_meta;
+static uint32_t fs_off;
+
+static inline int
+fsfind(const char *name, ino_t * ino)
+{
+    char buf[DEV_BSIZE];
+    struct dirent *d;
+    char *s;
+    ssize_t n;
+
+    fs_off = 0;
+    while ((n = fsread(*ino, buf, DEV_BSIZE)) > 0)
+	for (s = buf; s < buf + DEV_BSIZE;) {
+	    d = (void *)s;
+	    if (ls)
+		printf("%s ", d->d_name);
+	    else if (!strcmp(name, d->d_name)) {
+		*ino = d->d_fileno;
+		return d->d_type;
+	    }
+	    s += d->d_reclen;
+	}
+    if (n != -1 && ls)
+	putchar('\n');
+    return 0;
+}
+
+static ino_t
+lookup(const char *path)
+{
+    char name[MAXNAMLEN + 1];
+    const char *s;
+    ino_t ino;
+    ssize_t n;
+    int dt;
+
+    ino = ROOTINO;
+    dt = DT_DIR;
+    for (;;) {
+	if (*path == '/')
+	    path++;
+	if (!*path)
+	    break;
+	for (s = path; *s && *s != '/'; s++);
+	if ((n = s - path) > MAXNAMLEN)
+	    return 0;
+	ls = *path == '?' && n == 1 && !*s;
+	memcpy(name, path, n);
+	name[n] = 0;
+	if ((dt = fsfind(name, &ino)) <= 0)
+	    break;
+	path = s;
+    }
+    return dt == DT_REG ? ino : 0;
+}
+
+static ssize_t
+fsread(ino_t inode, void *buf, size_t nbyte)
+{
+    static struct dinode din;
+    static ino_t inomap;
+    static daddr_t blkmap, indmap;
+    char *blkbuf;
+    ufs_daddr_t *indbuf;
+    struct fs *fs;
+    char *s;
+    ufs_daddr_t lbn, addr;
+    daddr_t vbaddr;
+    size_t n, nb, off, vboff;
+
+    blkbuf = dmadat->blkbuf;
+    indbuf = dmadat->indbuf;
+    fs = (struct fs *)dmadat->sbbuf;
+    if (!dsk_meta) {
+	inomap = 0;
+	if (dskread(fs, SBOFF / DEV_BSIZE, SBSIZE / DEV_BSIZE))
+	    return -1;
+	if (fs->fs_magic != FS_MAGIC) {
+	    printf("Not ufs\n");
+	    return -1;
+	}
+	dsk_meta++;
+    }
+    if (!inode)
+	return 0;
+    if (inomap != inode) {
+	if (dskread(blkbuf, INO_TO_VBA(fs, inode), DBPERVBLK))
+	    return -1;
+	din = ((struct dinode *)blkbuf)[INO_TO_VBO(fs, inode)];
+	inomap = inode;
+	fs_off = 0;
+	blkmap = indmap = 0;
+    }
+    s = buf;
+    if (nbyte > (n = din.di_size - fs_off))
+	nbyte = n;
+    nb = nbyte;
+    while (nb) {
+	lbn = lblkno(fs, fs_off);
+	off = blkoff(fs, fs_off);
+	if (lbn < NDADDR)
+	    addr = din.di_db[lbn];
+	else {
+	    vbaddr = FS_TO_VBA(fs, din.di_ib[0], sizeof(indbuf[0]) *
+		((lbn - NDADDR) % NINDIR(fs)));
+	    if (indmap != vbaddr) {
+		if (dskread(indbuf, vbaddr, DBPERVBLK))
+		    return -1;
+		indmap = vbaddr;
+	    }
+	    addr = indbuf[(lbn - NDADDR) % INDIRPERVBLK];
+	}
+	vbaddr = FS_TO_VBA(fs, addr, off);
+	vboff = FS_TO_VBO(fs, addr, off);
+	n = dblksize(fs, &din, lbn) - (off & ~VBLKMASK);
+	if (n > VBLKSIZE)
+		n = VBLKSIZE;
+	if (blkmap != vbaddr) {
+	    if (dskread(blkbuf, vbaddr, n >> DEV_BSHIFT))
+		return -1;
+	    blkmap = vbaddr;
+	}
+	n -= vboff;
+	if (n > nb)
+	    n = nb;
+	memcpy(s, blkbuf + vboff, n);
+	s += n;
+	fs_off += n;
+	nb -= n;
+    }
+    return nbyte;
+}
+
-- 
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