Quick fix for msdsofs_write() on alphas and other machines with either

longs larger than 32 bits or strict alignment requirements.

pm_fatmask had type u_long, but it must have a type that has precisely
32 bits and this type must be no smaller than int, so that ~pmp->pm_fatmask
has no bits above the 31st set.  Otherwise, comparisons between (cn
| ~pmp->pm_fatmask) and magic 32-bit "cluster" numbers always fail.
The correct fix is to use the C99 type uint_least32_t and mask with
0xffffffff.  The quick fix is to use u_int32_t and assume that ints
have

msdosfs metadata is riddled with unaligned fields, and on alphas,
unaligned_fixup() apparently has problems fixing up the unaligned
accesses caused by this.  The quick fix is to not comment out the
NetBSD code that sort of handles this, and define UNALIGNED_ACCESS on
i386's so that the code doesn't change on i386's.  The correct fix
would define UNALIGNED_ACCESS in a central machine-dependent header
and maybe add some extra cases to unaligned_fixup().  UNALIGNED_ACCESS
is also tested in isofs.

Submitted by:	parts by Mark Abene <phiber@radicalmedia.com>
PR:		19086

2 files changed, 8 insertions, 2 deletions

diff --git a/sys/fs/msdosfs/bpb.h b/sys/fs/msdosfs/bpb.h
index 88b9eef..42c941b 100644
--- a/sys/fs/msdosfs/bpb.h
+++ b/sys/fs/msdosfs/bpb.h
@@ -113,8 +113,14 @@ struct bpb_a {
  * 16-bit and 32-bit quantities on byte boundaries.  If this is not true,
  * use the macros for the big-endian case.
  */
+
 #include <machine/endian.h>
-#if (BYTE_ORDER == LITTLE_ENDIAN) 			/* && defined(UNALIGNED_ACCESS) */
+
+#ifdef __i386__
+#define	UNLALIGNED_ACCESS
+#endif
+
+#if (BYTE_ORDER == LITTLE_ENDIAN) && defined(UNALIGNED_ACCESS)
 #define	getushort(x)	*((u_int16_t *)(x))
 #define	getulong(x)	*((u_int32_t *)(x))
 #define	putushort(p, v)	(*((u_int16_t *)(p)) = (v))
diff --git a/sys/fs/msdosfs/msdosfsmount.h b/sys/fs/msdosfs/msdosfsmount.h
index adcfad0..da49190 100644
--- a/sys/fs/msdosfs/msdosfsmount.h
+++ b/sys/fs/msdosfs/msdosfsmount.h
@@ -84,7 +84,7 @@ struct msdosfsmount {
 	u_long pm_fatblocksize;	/* size of fat blocks in bytes */
 	u_long pm_fatblocksec;	/* size of fat blocks in sectors */
 	u_long pm_fatsize;	/* size of fat in bytes */
-	u_long pm_fatmask;	/* mask to use for fat numbers */
+	u_int32_t pm_fatmask;	/* mask to use for fat numbers */
 	u_long pm_fsinfo;	/* fsinfo block number */
 	u_long pm_nxtfree;	/* next free cluster in fsinfo block */
 	u_int pm_fatmult;	/* these 2 values are used in fat */