Fix our NTFS readdir function.

To check a directory's in-use bitmap bit by bit, we use
a pointer to an 8 bit wide unsigned value.

The index used to dereference this pointer is calculated
by shifting the bit index right 3 bits.  Then we do a
logical AND with the bit# represented by the lower 3
bits of the bit index.

This is an idiomatic way of iterating through a bit map
with simple bitwise operations.

This commit fixes the bug that we only checked bits
3:0 of each 8 bit chunk, because we only used bits 1:0
of the bit index for the bit# in the current 8 bit value.
This resulted in files not being returned by getdirentries(2).

Change the type of the bit map pointer from `char *' to
`u_int8_t *'.

1 files changed, 3 insertions, 3 deletions

diff --git a/sys/fs/ntfs/ntfs_subr.c b/sys/fs/ntfs/ntfs_subr.c
index fb46539e3ef2..de6ac6015cf5 100644
--- a/sys/fs/ntfs/ntfs_subr.c
+++ b/sys/fs/ntfs/ntfs_subr.c
@@ -1125,7 +1125,7 @@ ntfs_ntreaddir(
 	struct ntvattr *bmvap = NULL;	/* BitMap attribute */
 	struct ntvattr *iavap = NULL;	/* IndexAllocation attribute */
 	caddr_t         rdbuf;		/* Buffer to read directory's blocks  */
-	u_char         *bmp = NULL;	/* Bitmap */
+	u_int8_t       *bmp = NULL;	/* Bitmap */
 	u_int32_t       blsize;		/* Index allocation size (2048) */
 	u_int32_t       rdsize;		/* Length of data to read */
 	u_int32_t       attrnum;	/* Current attribute type */
@@ -1162,7 +1162,7 @@ ntfs_ntreaddir(
 			error = ENOTDIR;
 			goto fail;
 		}
-		MALLOC(bmp, u_char *, bmvap->va_datalen, M_TEMP, M_WAITOK);
+		MALLOC(bmp, u_int8_t *, bmvap->va_datalen, M_TEMP, M_WAITOK);
 		error = ntfs_readattr(ntmp, ip, NTFS_A_INDXBITMAP, "$I30", 0,
 				       bmvap->va_datalen, bmp, NULL);
 		if (error)
@@ -1244,7 +1244,7 @@ ntfs_ntreaddir(
 				blnum++;
 
 			while (ntfs_cntob(blnum * cpbl) < iavap->va_datalen) {
-				if (bmp[blnum >> 3] & (1 << (blnum & 3)))
+				if (bmp[blnum >> 3] & (1 << (blnum & 7)))
 					break;
 				blnum++;
 			}