Date: Fri, 11 Jan 2002 03:01:27 +0000 From: Ian Dowse <iedowse@maths.tcd.ie> To: John Baldwin <jhb@FreeBSD.org> Cc: Bernd Walter <ticso@cicely8.cicely.de>, freebsd-alpha@FreeBSD.org, Christian Weisgerber <naddy@mips.inka.de> Subject: Re: cvs commit: src/sys/boot/i386/boot2 boot2.c Message-ID: <200201110301.aa94114@salmon.maths.tcd.ie> In-Reply-To: Your message of "Thu, 10 Jan 2002 12:47:36 PST." <XFMail.020110124736.jhb@FreeBSD.org>
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An alternative patch for the alpha 16k/2k block size issue is below.
This is more complex, but it should make boot1 work for any block
size without the need for large buffers or a #defined maximum block
size. It is completely untested, apart the fact that it compiles,
so it is unlikely to work first time...
I'd be grateful if people could try this out, even on a 8k/1k
filesystem and report and/or help debug any problems.
Ian
Index: sys.c
===================================================================
RCS file: /dump/FreeBSD-CVS/src/sys/boot/alpha/boot1/sys.c,v
retrieving revision 1.4
diff -u -r1.4 sys.c
--- sys.c 1 Sep 1999 09:11:07 -0000 1.4
+++ sys.c 11 Jan 2002 02:39:25 -0000
@@ -44,18 +44,24 @@
struct inode inode;
int boff = 0;
-#if 0
-/* #define BUFSIZE 4096 */
-#define BUFSIZE MAXBSIZE
+/*
+ * 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)
-static char buf[BUFSIZE], fsbuf[SBSIZE], iobuf[MAXBSIZE];
-#endif
-
-#define BUFSIZE 8192
-#define MAPBUFSIZE BUFSIZE
-static char buf[BUFSIZE], fsbuf[BUFSIZE], iobuf[BUFSIZE];
-
-static char mapbuf[MAPBUFSIZE];
+static char fsbuf[SBSIZE], iobuf[VBLKSIZE];
+ufs_daddr_t mapbuf[VBLKSIZE / sizeof(ufs_daddr_t)];
static int mapblock;
int poff;
@@ -71,7 +77,7 @@
readit(char *buffer, int count)
{
int logno, off, size;
- int cnt2, bnum2;
+ int cnt2, fsblk, bnum2;
struct fs *fs_copy;
int n = 0;
@@ -81,8 +87,13 @@
fs_copy = fs;
off = blkoff(fs_copy, poff);
logno = lblkno(fs_copy, poff);
- cnt2 = size = blksize(fs_copy, &inode, logno);
- bnum2 = fsbtodb(fs_copy, block_map(logno)) + boff;
+ fsblk = block_map(logno);
+ cnt2 = blksize(fs_copy, &inode, logno) - (off & ~VBLKMASK);
+ if (cnt2 > VBLKSIZE)
+ cnt2 = VBLKSIZE;
+ size = cnt2;
+ bnum2 = FS_TO_VBA(fs_copy, fsblk, off) + boff;
+ off = FS_TO_VBO(fs_copy, fsblk, off);
if ( (!off) && (size <= count)) {
devread(buffer, bnum2, cnt2);
} else {
@@ -104,14 +115,14 @@
find(char *path)
{
char *rest, ch;
- int block, off, loc, ino = ROOTINO;
+ int block, blklen, fsboff, off, loc, ino = ROOTINO;
struct dirent *dp;
char list_only;
list_only = (path[0] == '?' && path[1] == '\0');
loop:
- devread(iobuf, fsbtodb(fs, ino_to_fsba(fs, ino)) + boff, fs->fs_bsize);
- bcopy((void *)&((struct dinode *)iobuf)[ino % fs->fs_inopb],
+ devread(iobuf, INO_TO_VBA(fs, ino) + boff, VBLKSIZE);
+ bcopy((void *)&((struct dinode *)iobuf)[INO_TO_VBO(fs, ino)],
(void *)&inode.i_din,
sizeof (struct dinode));
if (!*path)
@@ -132,10 +143,14 @@
return 0;
}
}
- if (!(off = blkoff(fs, loc))) {
+ if (!(off = (loc & VBLKMASK))) {
block = lblkno(fs, loc);
- devread(iobuf, fsbtodb(fs, block_map(block)) + boff,
- blksize(fs, &inode, block));
+ fsboff = blkoff(fs, loc);
+ blklen = blksize(fs, &inode, block) - fsboff;
+ if (blklen > VBLKSIZE)
+ blklen = VBLKSIZE;
+ devread(iobuf, FS_TO_VBA(fs, block_map(block), fsboff) + boff,
+ blklen);
}
dp = (struct dirent *)(iobuf + off);
loc += dp->d_reclen;
@@ -156,11 +171,13 @@
int bnum;
if (file_block < NDADDR)
return(inode.i_db[file_block]);
- if ((bnum=fsbtodb(fs, inode.i_ib[0])+boff) != mapblock) {
- devread(mapbuf, bnum, fs->fs_bsize);
+ bnum = FS_TO_VBA(fs, inode.i_ib[0], sizeof(mapbuf[0]) *
+ ((file_block - NDADDR) % NINDIR(fs))) + boff;
+ if (bnum != mapblock) {
+ devread(mapbuf, bnum, VBLKSIZE);
mapblock = bnum;
}
- return (((int *)mapbuf)[(file_block - NDADDR) % NINDIR(fs)]);
+ return (mapbuf[(file_block - NDADDR) % INDIRPERVBLK]);
}
#ifdef COMPAT_UFS
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