FAT32 support from NetBSD by Wolfgang Solfrank.

1 files changed, 163 insertions, 78 deletions

diff --git a/sys/msdosfs/msdosfs_fat.c b/sys/msdosfs/msdosfs_fat.c
index fe044d1a6e3..a215bdc98bc 100644
--- a/sys/msdosfs/msdosfs_fat.c
+++ b/sys/msdosfs/msdosfs_fat.c
@@ -1,9 +1,9 @@
-/*	$OpenBSD: msdosfs_fat.c,v 1.4 1997/03/02 18:01:56 millert Exp $	*/
-/*	$NetBSD: msdosfs_fat.c,v 1.24 1996/10/13 04:16:32 christos Exp $	*/
+/*	$OpenBSD: msdosfs_fat.c,v 1.5 1998/01/11 20:39:08 provos Exp $	*/
+/*	$NetBSD: msdosfs_fat.c,v 1.26 1997/10/17 11:24:02 ws Exp $	*/
 
 /*-
- * Copyright (C) 1994, 1995 Wolfgang Solfrank.
- * Copyright (C) 1994, 1995 TooLs GmbH.
+ * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
+ * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
  * All rights reserved.
  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
  *
@@ -83,9 +83,6 @@ int fc_lmdistance[LMMAX];	/* counters for how far off the last
 				 * cluster mapped entry was. */
 int fc_largedistance;		/* off by more than LMMAX		 */
 
-/* Byte offset in FAT on filesystem pmp, cluster cn */
-#define	FATOFS(pmp, cn)	(FAT12(pmp) ? (cn) * 3 / 2 : (cn) * 2)
-
 static void fatblock __P((struct msdosfsmount *, u_long, u_long *, u_long *,
 			  u_long *));
 void updatefats __P((struct msdosfsmount *, struct buf *, u_long));
@@ -109,7 +106,8 @@ fatblock(pmp, ofs, bnp, sizep, bop)
 	bn = ofs / pmp->pm_fatblocksize * pmp->pm_fatblocksec;
 	size = min(pmp->pm_fatblocksec, pmp->pm_FATsecs - bn)
 	    * pmp->pm_BytesPerSec;
-	bn += pmp->pm_fatblk;
+	bn += pmp->pm_fatblk + pmp->pm_curfat * pmp->pm_FATsecs;
+
 	if (bnp)
 		*bnp = bn;
 	if (sizep)
@@ -155,7 +153,6 @@ pcbmap(dep, findcn, bnp, cnp, sp)
 	u_long bp_bn = -1;
 	struct msdosfsmount *pmp = dep->de_pmp;
 	u_long bsize;
-	int fat12 = FAT12(pmp);	/* 12 bit fat	 */
 
 	fc_bmapcalls++;
 
@@ -217,7 +214,10 @@ pcbmap(dep, findcn, bnp, cnp, sp)
 	 * Handle all other files or directories the normal way.
 	 */
 	for (; i < findcn; i++) {
-		if (MSDOSFSEOF(cn))
+		/*
+		 * Stop with all reserved clusters, not just with EOF.
+		 */
+		if ((cn | ~pmp->pm_fatmask) >= CLUST_RSRVD)
 			goto hiteof;
 		byteoffset = FATOFS(pmp, cn);
 		fatblock(pmp, byteoffset, &bn, &bsize, &bo);
@@ -232,23 +232,25 @@ pcbmap(dep, findcn, bnp, cnp, sp)
 			bp_bn = bn;
 		}
 		prevcn = cn;
-		cn = getushort(&bp->b_data[bo]);
-		if (fat12) {
-			if (prevcn & 1)
-				cn >>= 4;
-			cn &= 0x0fff;
-			/*
-			 * Force the special cluster numbers in the range
-			 * 0x0ff0-0x0fff to be the same as for 16 bit
-			 * cluster numbers to let the rest of msdosfs think
-			 * it is always dealing with 16 bit fats.
-			 */
-			if ((cn & 0x0ff0) == 0x0ff0)
-				cn |= 0xf000;
-		}
+		if (FAT32(pmp))
+			cn = getulong(&bp->b_data[bo]);
+		else
+			cn = getushort(&bp->b_data[bo]);
+		if (FAT12(pmp) && (prevcn & 1))
+			cn >>= 4;
+		cn &= pmp->pm_fatmask;
+
+		/*
+		 * Force the special cluster numbers
+		 * to be the same for all cluster sizes
+		 * to let the rest of msdosfs handle
+		 * all cases the same.
+		 */
+		if ((cn | ~pmp->pm_fatmask) >= CLUST_RSRVD)
+			cn |= ~pmp->pm_fatmask;
 	}
 
-	if (!MSDOSFSEOF(cn)) {
+	if (!MSDOSFSEOF(pmp, cn)) {
 		if (bp)
 			brelse(bp);
 		if (bnp)
@@ -317,7 +319,9 @@ fc_purge(dep, frcn)
 }
 
 /*
- * Update all copies of the fat. The first copy is updated last.
+ * Update the fat.
+ * If mirroring the fat, update all copies, with the first copy as last.
+ * Else update only the current fat (ignoring the others).
  *
  * pmp	 - msdosfsmount structure for filesystem to update
  * bp	 - addr of modified fat block
@@ -338,32 +342,76 @@ updatefats(pmp, bp, fatbn)
 #endif
 
 	/*
-	 * Now copy the block(s) of the modified fat to the other copies of
-	 * the fat and write them out.  This is faster than reading in the
-	 * other fats and then writing them back out.  This could tie up
-	 * the fat for quite a while. Preventing others from accessing it.
-	 * To prevent us from going after the fat quite so much we use
-	 * delayed writes, unless they specfied "synchronous" when the
-	 * filesystem was mounted.  If synch is asked for then use
-	 * bwrite()'s and really slow things down.
+	 * If we have an FSInfo block, update it.
 	 */
-	for (i = 1; i < pmp->pm_FATs; i++) {
-		fatbn += pmp->pm_FATsecs;
-		/* getblk() never fails */
-		bpn = getblk(pmp->pm_devvp, fatbn, bp->b_bcount, 0, 0);
-		bcopy(bp->b_data, bpn->b_data, bp->b_bcount);
-		if (pmp->pm_flags & MSDOSFSMNT_WAITONFAT)
-			bwrite(bpn);
-		else
-			bdwrite(bpn);
+	if (pmp->pm_fsinfo) {
+		u_long cn = pmp->pm_nxtfree;
+
+		if (pmp->pm_freeclustercount
+		    && (pmp->pm_inusemap[cn / N_INUSEBITS]
+			& (1 << (cn % N_INUSEBITS)))) {
+			/*
+			 * The cluster indicated in FSInfo isn't free
+			 * any longer.  Got get a new free one.
+			 */
+			for (cn = 0; cn < pmp->pm_maxcluster;)
+				if (pmp->pm_inusemap[cn / N_INUSEBITS] != (u_int)-1)
+					break;
+			pmp->pm_nxtfree = cn
+				+ ffs(pmp->pm_inusemap[cn / N_INUSEBITS]
+				      ^ (u_int)-1) - 1;
+		}
+		if (bread(pmp->pm_devvp, pmp->pm_fsinfo, 1024, NOCRED, &bpn) != 0) {
+			/*
+			 * Ignore the error, but turn off FSInfo update for the future.
+			 */
+			pmp->pm_fsinfo = 0;
+			brelse(bpn);
+		} else {
+			struct fsinfo *fp = (struct fsinfo *)bpn->b_data;
+
+			putulong(fp->fsinfree, pmp->pm_freeclustercount);
+			putulong(fp->fsinxtfree, pmp->pm_nxtfree);
+			if (pmp->pm_flags & MSDOSFSMNT_WAITONFAT)
+				bwrite(bpn);
+			else
+				bdwrite(bpn);
+		}
 	}
+
+	if (pmp->pm_flags & MSDOSFS_FATMIRROR) {
+		/*
+		 * Now copy the block(s) of the modified fat to the other copies of
+		 * the fat and write them out.  This is faster than reading in the
+		 * other fats and then writing them back out.  This could tie up
+		 * the fat for quite a while. Preventing others from accessing it.
+		 * To prevent us from going after the fat quite so much we use
+		 * delayed writes, unless they specfied "synchronous" when the
+		 * filesystem was mounted.  If synch is asked for then use
+		 * bwrite()'s and really slow things down.
+		 */
+		for (i = 1; i < pmp->pm_FATs; i++) {
+			fatbn += pmp->pm_FATsecs;
+			/* getblk() never fails */
+			bpn = getblk(pmp->pm_devvp, fatbn, bp->b_bcount, 0, 0);
+			bcopy(bp->b_data, bpn->b_data, bp->b_bcount);
+			if (pmp->pm_flags & MSDOSFSMNT_WAITONFAT)
+				bwrite(bpn);
+			else
+				bdwrite(bpn);
+		}
+	}
+
 	/*
-	 * Write out the first fat last.
+	 * Write out the first (or current) fat last.
 	 */
 	if (pmp->pm_flags & MSDOSFSMNT_WAITONFAT)
 		bwrite(bp);
 	else
 		bdwrite(bp);
+	/*
+	 * Maybe update fsinfo sector here?
+	 */
 }
 
 /*
@@ -414,15 +462,17 @@ clusterfree(pmp, cluster, oldcnp)
 	int error;
 	u_long oldcn;
 
+	usemap_free(pmp, cluster);
 	error = fatentry(FAT_GET_AND_SET, pmp, cluster, &oldcn, MSDOSFSFREE);
-	if (error)
+	if (error) {
+		usemap_alloc(pmp, cluster);
 		return (error);
+	}
 	/*
 	 * If the cluster was successfully marked free, then update
 	 * the count of free clusters, and turn off the "allocated"
 	 * bit in the "in use" cluster bit map.
 	 */
-	usemap_free(pmp, cluster);
 	if (oldcnp)
 		*oldcnp = oldcn;
 	return (0);
@@ -460,7 +510,7 @@ fatentry(function, pmp, cn, oldcontents, newcontents)
 	u_long bn, bo, bsize, byteoffset;
 	struct buf *bp;
 
-#if 0
+#ifdef MSDOSFS_DEBUG
 	 printf("fatentry(func %d, pmp %08x, clust %d, oldcon %08x, newcon %d)\n",
 	     function, pmp, cluster, oldcontents, newcontents);
 #endif
@@ -498,19 +548,21 @@ fatentry(function, pmp, cn, oldcontents, newcontents)
 	}
 	
 	if (function & FAT_GET) {
-		readcn = getushort(&bp->b_data[bo]);
-		if (FAT12(pmp)) {
-			if (cn & 1)
-				readcn >>= 4;
-			readcn &= 0x0fff;
-			/* map certain 12 bit fat entries to 16 bit */
-			if ((readcn & 0x0ff0) == 0x0ff0)
-				readcn |= 0xf000;
-		}
+		if (FAT32(pmp))
+			readcn = getulong(&bp->b_data[bo]);
+		else
+			readcn = getushort(&bp->b_data[bo]);
+		if (FAT12(pmp) & (cn & 1))
+			readcn >>= 4;
+		readcn &= pmp->pm_fatmask;
+		/* map reserved fat entries to same values for all fats */
+		if ((readcn | ~pmp->pm_fatmask) >= CLUST_RSRVD)
+			readcn |= ~pmp->pm_fatmask;
 		*oldcontents = readcn;
 	}
 	if (function & FAT_SET) {
-		if (FAT12(pmp)) {
+		switch (pmp->pm_fatmask) {
+		case FAT12_MASK:
 			readcn = getushort(&bp->b_data[bo]);
 			if (cn & 1) {
 				readcn &= 0x000f;
@@ -520,8 +572,21 @@ fatentry(function, pmp, cn, oldcontents, newcontents)
 				readcn |= newcontents & 0xfff;
 			}
 			putushort(&bp->b_data[bo], readcn);
-		} else
+			break;
+		case FAT16_MASK:
 			putushort(&bp->b_data[bo], newcontents);
+			break;
+		case FAT32_MASK:
+			/*
+			 * According to spec we have to retain the
+			 * high order bits of the fat entry.
+			 */
+			readcn = getulong(&bp->b_data[bo]);
+			readcn &= ~FAT32_MASK;
+			readcn |= newcontents & FAT32_MASK;
+			putulong(&bp->b_data[bo], readcn);
+			break;
+		}
 		updatefats(pmp, bp, bn);
 		bp = NULL;
 		pmp->pm_fmod = 1;
@@ -571,7 +636,8 @@ fatchain(pmp, start, count, fillwith)
 		while (count > 0) {
 			start++;
 			newc = --count > 0 ? start : fillwith;
-			if (FAT12(pmp)) {
+			switch (pmp->pm_fatmask) {
+			case FAT12_MASK:
 				readcn = getushort(&bp->b_data[bo]);
 				if (start & 1) {
 					readcn &= 0xf000;
@@ -584,9 +650,18 @@ fatchain(pmp, start, count, fillwith)
 				bo++;
 				if (!(start & 1))
 					bo++;
-			} else {
+				break;
+			case FAT16_MASK:
 				putushort(&bp->b_data[bo], newc);
 				bo += 2;
+				break;
+			case FAT32_MASK:
+				readcn = getulong(&bp->b_data[bo]);
+				readcn &= ~pmp->pm_fatmask;
+				readcn |= newc & pmp->pm_fatmask;
+				putulong(&bp->b_data[bo], readcn);
+				bo += 4;
+				break;
 			}
 			if (bo >= bsize)
 				break;
@@ -659,7 +734,10 @@ chainalloc(pmp, start, count, fillwith, retcluster, got)
 	u_long *got;
 {
 	int error;
-	
+	u_long cl, n;
+
+	for (cl = start, n = count; n-- > 0;)
+		usemap_alloc(pmp, cl++);
 	if ((error = fatchain(pmp, start, count, fillwith)) != 0)
 		return (error);
 #ifdef MSDOSFS_DEBUG
@@ -670,8 +748,6 @@ chainalloc(pmp, start, count, fillwith, retcluster, got)
 		*retcluster = start;
 	if (got)
 		*got = count;
-	while (count-- > 0)
-		usemap_alloc(pmp, start++);
 	return (0);
 }
 
@@ -801,8 +877,9 @@ freeclusterchain(pmp, cluster)
 			lbn = bn;
 		}
 		usemap_free(pmp, cluster);
-		readcn = getushort(&bp->b_data[bo]);
-		if (FAT12(pmp)) {
+		switch (pmp->pm_fatmask) {
+		case FAT12_MASK:
+			readcn = getushort(&bp->b_data[bo]);
 			if (cluster & 1) {
 				cluster = readcn >> 4;
 				readcn &= 0x000f;
@@ -813,13 +890,20 @@ freeclusterchain(pmp, cluster)
 				readcn |= MSDOSFSFREE & 0xfff;
 			}
 			putushort(&bp->b_data[bo], readcn);
-			cluster &= 0x0fff;
-			if ((cluster&0x0ff0) == 0x0ff0)
-				cluster |= 0xf000;
-		} else {
-			cluster = readcn;
+			break;
+		case FAT16_MASK:
+			cluster = getushort(&bp->b_data[bo]);
 			putushort(&bp->b_data[bo], MSDOSFSFREE);
+			break;
+		case FAT32_MASK:
+			cluster = getulong(&bp->b_data[bo]);
+			putulong(&bp->b_data[bo],
+				 (MSDOSFSFREE & FAT32_MASK) | (cluster & ~FAT32_MASK));
+			break;
 		}
+		cluster &= pmp->pm_fatmask;
+		if ((cluster | ~pmp->pm_fatmask) >= CLUST_RSRVD)
+			cluster |= pmp->pm_fatmask;
 	}
 	if (bp)
 		updatefats(pmp, bp, bn);
@@ -837,7 +921,6 @@ fillinusemap(pmp)
 	struct buf *bp = NULL;
 	u_long cn, readcn;
 	int error;
-	int fat12 = FAT12(pmp);
 	u_long bn, bo, bsize, byteoffset;
 
 	/*
@@ -867,12 +950,13 @@ fillinusemap(pmp)
 				return (error);
 			}
 		}
-		readcn = getushort(&bp->b_data[bo]);
-		if (fat12) {
-			if (cn & 1)
-				readcn >>= 4;
-			readcn &= 0x0fff;
-		}
+		if (FAT32(pmp))
+			readcn = getulong(&bp->b_data[bo]);
+		else
+			readcn = getushort(&bp->b_data[bo]);
+		if (FAT12(pmp) && (cn & 1))
+			readcn >>= 4;
+		readcn &= pmp->pm_fatmask;
 
 		if (readcn == 0)
 			usemap_free(pmp, cn);
@@ -913,7 +997,8 @@ extendfile(dep, count, bpp, ncp, flags)
 	/*
 	 * Don't try to extend the root directory
 	 */
-	if (DETOV(dep)->v_flag & VROOT) {
+	if (dep->de_StartCluster == MSDOSFSROOT
+	    && (dep->de_Attributes & ATTR_DIRECTORY)) {
 		printf("extendfile(): attempt to extend root directory\n");
 		return (ENOSPC);
 	}