Adopt FreeBSD's code for non-DEV_BSIZE formatted MSDOSFS filesystems.

Enables devices (e.g. newer iPods, various other mp3 players) that use
2048 byte sectors.

Inspired by original diffs from weingart@ and Alexey Vatchenk.

ok tom@ pedro@ deraadt@ weingart@ marco@

3 files changed, 44 insertions, 16 deletions

diff --git a/sys/msdosfs/msdosfs_fat.c b/sys/msdosfs/msdosfs_fat.c
index c9127de9d85..325620473ee 100644
--- a/sys/msdosfs/msdosfs_fat.c
+++ b/sys/msdosfs/msdosfs_fat.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: msdosfs_fat.c,v 1.18 2006/10/03 19:49:06 pedro Exp $	*/
+/*	$OpenBSD: msdosfs_fat.c,v 1.19 2006/12/16 12:44:05 krw Exp $	*/
 /*	$NetBSD: msdosfs_fat.c,v 1.26 1997/10/17 11:24:02 ws Exp $	*/
 
 /*-
@@ -104,8 +104,7 @@ fatblock(pmp, ofs, bnp, sizep, bop)
 	uint32_t bn, size;
 
 	bn = ofs / pmp->pm_fatblocksize * pmp->pm_fatblocksec;
-	size = min(pmp->pm_fatblocksec, pmp->pm_FATsecs - bn)
-	    * pmp->pm_BytesPerSec;
+	size = min(pmp->pm_fatblocksec, pmp->pm_FATsecs - bn) * DEV_BSIZE;
 	bn += pmp->pm_fatblk + pmp->pm_curfat * pmp->pm_FATsecs;
 
 	if (bnp)
@@ -365,7 +364,8 @@ updatefats(pmp, bp, fatbn)
 				+ ffs(pmp->pm_inusemap[cn / N_INUSEBITS]
 				      ^ (u_int)-1) - 1;
 		}
-		if (bread(pmp->pm_devvp, pmp->pm_fsinfo, 1024, NOCRED, &bpn) != 0) {
+		if (bread(pmp->pm_devvp, pmp->pm_fsinfo, fsi_size(pmp), NOCRED,
+		    &bpn) != 0) {
 			/*
 			 * Ignore the error, but turn off FSInfo update for the future.
 			 */
diff --git a/sys/msdosfs/msdosfs_vfsops.c b/sys/msdosfs/msdosfs_vfsops.c
index e64bbe7ba28..c3442966cc1 100644
--- a/sys/msdosfs/msdosfs_vfsops.c
+++ b/sys/msdosfs/msdosfs_vfsops.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: msdosfs_vfsops.c,v 1.45 2006/12/15 03:04:24 krw Exp $	*/
+/*	$OpenBSD: msdosfs_vfsops.c,v 1.46 2006/12/16 12:44:05 krw Exp $	*/
 /*	$NetBSD: msdosfs_vfsops.c,v 1.48 1997/10/18 02:54:57 briggs Exp $	*/
 
 /*-
@@ -294,7 +294,7 @@ msdosfs_mountfs(devvp, mp, p, argp)
 	 * Read the boot sector of the filesystem, and then check the
 	 * boot signature.  If not a dos boot sector then error out.
 	 */
-	if ((error = bread(devvp, 0, 512, NOCRED, &bp)) != 0)
+	if ((error = bread(devvp, 0, 2048, NOCRED, &bp)) != 0)
 		goto error_exit;
 	bp->b_flags |= B_AGE;
 	bsp = (union bootsector *)bp->b_data;
@@ -322,6 +322,9 @@ msdosfs_mountfs(devvp, mp, p, argp)
 	pmp->pm_Heads = getushort(b50->bpbHeads);
 	pmp->pm_Media = b50->bpbMedia;
 
+	/* Determine the number of DEV_BSIZE blocks in a MSDOSFS sector */
+	pmp->pm_BlkPerSec = pmp->pm_BytesPerSec / DEV_BSIZE;
+
     	if (!pmp->pm_BytesPerSec || !SecPerClust || pmp->pm_SecPerTrack > 63) {
 		error = EFTYPE;
 		goto error_exit;
@@ -352,25 +355,44 @@ msdosfs_mountfs(devvp, mp, p, argp)
 	} else
 	        pmp->pm_flags |= MSDOSFS_FATMIRROR;
 
-	pmp->pm_fatblk = pmp->pm_ResSectors;
+	/*
+	 * More sanity checks:
+	 *	MSDOSFS sectors per cluster: >0 && power of 2
+	 *	MSDOSFS sector size: >= DEV_BSIZE && power of 2
+	 *	HUGE sector count: >0
+	 * 	FAT sectors: >0
+	 */
+	if ((SecPerClust == 0) || (SecPerClust & (SecPerClust - 1)) ||
+	    (pmp->pm_BytesPerSec < DEV_BSIZE) ||
+	    (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1)) ||
+	    (pmp->pm_HugeSectors == 0) || (pmp->pm_FATsecs == 0)) {
+		error = EINVAL;
+		goto error_exit;
+	}		
+	
+	pmp->pm_HugeSectors *= pmp->pm_BlkPerSec;
+	pmp->pm_HiddenSects *= pmp->pm_BlkPerSec;
+	pmp->pm_FATsecs *= pmp->pm_BlkPerSec;
+	pmp->pm_fatblk = pmp->pm_ResSectors * pmp->pm_BlkPerSec;
+	SecPerClust *= pmp->pm_BlkPerSec;
+
 	if (FAT32(pmp)) {
 	        pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
 		pmp->pm_firstcluster = pmp->pm_fatblk
 		        + (pmp->pm_FATs * pmp->pm_FATsecs);
-		pmp->pm_fsinfo = getushort(b710->bpbFSInfo);
+		pmp->pm_fsinfo = getushort(b710->bpbFSInfo) * pmp->pm_BlkPerSec;
 	} else {
 	        pmp->pm_rootdirblk = pmp->pm_fatblk +
 		        (pmp->pm_FATs * pmp->pm_FATsecs);
 		pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
-				       + pmp->pm_BytesPerSec - 1)
-		        / pmp->pm_BytesPerSec;/* in sectors */
+				       + DEV_BSIZE - 1) / DEV_BSIZE;
 		pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
 	}
 
 	pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
 	    SecPerClust;
 	pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1;
-	pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec;
+	pmp->pm_fatsize = pmp->pm_FATsecs * DEV_BSIZE;
 
 	if (pmp->pm_fatmask == 0) {
 		if (pmp->pm_maxcluster
@@ -417,14 +439,14 @@ msdosfs_mountfs(devvp, mp, p, argp)
 		pmp->pm_maxcluster = fat_max_clusters - 1;
 	}
 
-	pmp->pm_fatblocksec = pmp->pm_fatblocksize / pmp->pm_BytesPerSec;
-	pmp->pm_bnshift = ffs(pmp->pm_BytesPerSec) - 1;
+	pmp->pm_fatblocksec = pmp->pm_fatblocksize / DEV_BSIZE;
+	pmp->pm_bnshift = ffs(DEV_BSIZE) - 1;
 
 	/*
 	 * Compute mask and shift value for isolating cluster relative byte
 	 * offsets and cluster numbers from a file offset.
 	 */
-	pmp->pm_bpcluster = SecPerClust * pmp->pm_BytesPerSec;
+	pmp->pm_bpcluster = SecPerClust * DEV_BSIZE;
 	pmp->pm_crbomask = pmp->pm_bpcluster - 1;
 	pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
 
@@ -449,7 +471,8 @@ msdosfs_mountfs(devvp, mp, p, argp)
 	if (pmp->pm_fsinfo) {
 	        struct fsinfo *fp;
 
-		if ((error = bread(devvp, pmp->pm_fsinfo, 1024, NOCRED, &bp)) != 0)
+		if ((error = bread(devvp, pmp->pm_fsinfo, fsi_size(pmp),
+		    NOCRED, &bp)) != 0)
 		        goto error_exit;
 		fp = (struct fsinfo *)bp->b_data;
 		if (!bcmp(fp->fsisig1, "RRaA", 4)
diff --git a/sys/msdosfs/msdosfsmount.h b/sys/msdosfs/msdosfsmount.h
index 56f2cd971ff..45f72016fde 100644
--- a/sys/msdosfs/msdosfsmount.h
+++ b/sys/msdosfs/msdosfsmount.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: msdosfsmount.h,v 1.17 2006/12/15 03:04:24 krw Exp $	*/
+/*	$OpenBSD: msdosfsmount.h,v 1.18 2006/12/16 12:44:05 krw Exp $	*/
 /*	$NetBSD: msdosfsmount.h,v 1.16 1997/10/17 11:24:24 ws Exp $	*/
 
 /*-
@@ -59,6 +59,7 @@ struct msdosfsmount {
 	mode_t pm_mask;		/* mask to and with file protection bits */
 	struct vnode *pm_devvp;	/* vnode for block device mntd */
 	struct bpb50 pm_bpb;	/* BIOS parameter blk for this fs */
+	uint32_t pm_BlkPerSec;	/* # of DEV_BSIZE blocks in MSDOSFS sector */
 	uint32_t pm_FATsecs;	/* actual number of fat sectors */
 	uint32_t pm_fatblk;	/* block # of first FAT */
 	uint32_t pm_rootdirblk;	/* block # (cluster # for FAT32) of root directory number */
@@ -195,6 +196,10 @@ struct msdosfsmount {
 	 ? roottobn((pmp), (dirofs)) \
 	 : cntobn((pmp), (dirclu)))
 
+/* Calculate size of fsinfo block */
+#define fsi_size(pmp) \
+	(1024 << ((pmp)->pm_BlkPerSec >> 2))
+
 /*
  * Prototypes for MSDOSFS virtual filesystem operations
  */