From 52e85481fda504936a6f154be3e4cd1ca07a5997 Mon Sep 17 00:00:00 2001
From: Ian Dowse <iedowse@FreeBSD.org>
Date: Fri, 11 Jan 2002 16:14:34 +0000
Subject: [PATCH] Make the alpha boot1 work on filesystems that have a block
 size larger than 8k. We now use 4k buffers regardless of the filesystem block
 size, so there is no longer a static limit.

Simply increasing the buffer size from 8k to 16k as done on the
i386 doesn't work on the alpha, probably because it causes us
to overshoot boot1's 48k runtime memory limit.

Tested by:	naddy
---
 sys/boot/alpha/boot1/sys.c | 65 ++++++++++++++++++++++++--------------
 1 file changed, 41 insertions(+), 24 deletions(-)

diff --git a/sys/boot/alpha/boot1/sys.c b/sys/boot/alpha/boot1/sys.c
index 9dea3df7a93..ad0552386dc 100644
--- a/sys/boot/alpha/boot1/sys.c
+++ b/sys/boot/alpha/boot1/sys.c
@@ -44,18 +44,24 @@ struct fs *fs;
 struct inode inode;
 int boff = 0;
 
-#if 0
-/* #define BUFSIZE 4096 */
-#define BUFSIZE MAXBSIZE
-
-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];
+/*
+ * 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 fsbuf[SBSIZE], iobuf[VBLKSIZE];
+ufs_daddr_t mapbuf[VBLKSIZE / sizeof(ufs_daddr_t)];
 static int mapblock;
 
 int poff;
@@ -71,7 +77,7 @@ int
 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 @@ readit(char *buffer, int count)
 	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 @@ static int
 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 @@ find(char *path)
 		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 @@ block_map(int file_block)
 	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
-- 
2.45.2