diff --git a/libxfs/xfs_format.h b/libxfs/xfs_format.h
index d48e3a395..2af891d5d 100644
--- a/libxfs/xfs_format.h
+++ b/libxfs/xfs_format.h
@@ -690,6 +690,14 @@ struct xfs_agfl {
 	    ASSERT(xfs_daddr_to_agno(mp, d) == \
 		   xfs_daddr_to_agno(mp, (d) + (len) - 1)))
 
+/*
+ * Realtime bitmap information is accessed by the word, which is currently
+ * stored in host-endian format.
+ */
+union xfs_rtword_raw {
+	__u32		old;
+};
+
 /*
  * XFS Timestamps
  * ==============
diff --git a/libxfs/xfs_rtbitmap.c b/libxfs/xfs_rtbitmap.c
index 562b40a1a..f7be9ea5f 100644
--- a/libxfs/xfs_rtbitmap.c
+++ b/libxfs/xfs_rtbitmap.c
@@ -97,7 +97,6 @@ xfs_rtfind_back(
 	xfs_rtxnum_t	limit,		/* last rtext to look at */
 	xfs_rtxnum_t	*rtx)		/* out: start rtext found */
 {
-	xfs_rtword_t	*b;		/* current word in buffer */
 	int		bit;		/* bit number in the word */
 	xfs_fileoff_t	block;		/* bitmap block number */
 	struct xfs_buf	*bp;		/* buf for the block */
@@ -108,6 +107,7 @@ xfs_rtfind_back(
 	xfs_rtword_t	mask;		/* mask of relevant bits for value */
 	xfs_rtword_t	want;		/* mask for "good" values */
 	xfs_rtword_t	wdiff;		/* difference from wanted value */
+	xfs_rtword_t	incore;
 	unsigned int	word;		/* word number in the buffer */
 
 	/*
@@ -123,14 +123,14 @@ xfs_rtfind_back(
 	 * Get the first word's index & point to it.
 	 */
 	word = xfs_rtx_to_rbmword(mp, start);
-	b = xfs_rbmblock_wordptr(bp, word);
 	bit = (int)(start & (XFS_NBWORD - 1));
 	len = start - limit + 1;
 	/*
 	 * Compute match value, based on the bit at start: if 1 (free)
 	 * then all-ones, else all-zeroes.
 	 */
-	want = (*b & ((xfs_rtword_t)1 << bit)) ? -1 : 0;
+	incore = xfs_rtbitmap_getword(bp, word);
+	want = (incore & ((xfs_rtword_t)1 << bit)) ? -1 : 0;
 	/*
 	 * If the starting position is not word-aligned, deal with the
 	 * partial word.
@@ -147,7 +147,7 @@ xfs_rtfind_back(
 		 * Calculate the difference between the value there
 		 * and what we're looking for.
 		 */
-		if ((wdiff = (*b ^ want) & mask)) {
+		if ((wdiff = (incore ^ want) & mask)) {
 			/*
 			 * Different.  Mark where we are and return.
 			 */
@@ -172,12 +172,6 @@ xfs_rtfind_back(
 			}
 
 			word = mp->m_blockwsize - 1;
-			b = xfs_rbmblock_wordptr(bp, word);
-		} else {
-			/*
-			 * Go on to the previous word in the buffer.
-			 */
-			b--;
 		}
 	} else {
 		/*
@@ -193,7 +187,8 @@ xfs_rtfind_back(
 		/*
 		 * Compute difference between actual and desired value.
 		 */
-		if ((wdiff = *b ^ want)) {
+		incore = xfs_rtbitmap_getword(bp, word);
+		if ((wdiff = incore ^ want)) {
 			/*
 			 * Different, mark where we are and return.
 			 */
@@ -218,12 +213,6 @@ xfs_rtfind_back(
 			}
 
 			word = mp->m_blockwsize - 1;
-			b = xfs_rbmblock_wordptr(bp, word);
-		} else {
-			/*
-			 * Go on to the previous word in the buffer.
-			 */
-			b--;
 		}
 	}
 	/*
@@ -240,7 +229,8 @@ xfs_rtfind_back(
 		/*
 		 * Compute difference between actual and desired value.
 		 */
-		if ((wdiff = (*b ^ want) & mask)) {
+		incore = xfs_rtbitmap_getword(bp, word);
+		if ((wdiff = (incore ^ want) & mask)) {
 			/*
 			 * Different, mark where we are and return.
 			 */
@@ -271,7 +261,6 @@ xfs_rtfind_forw(
 	xfs_rtxnum_t	limit,		/* last rtext to look at */
 	xfs_rtxnum_t	*rtx)		/* out: start rtext found */
 {
-	xfs_rtword_t	*b;		/* current word in buffer */
 	int		bit;		/* bit number in the word */
 	xfs_fileoff_t	block;		/* bitmap block number */
 	struct xfs_buf	*bp;		/* buf for the block */
@@ -282,6 +271,7 @@ xfs_rtfind_forw(
 	xfs_rtword_t	mask;		/* mask of relevant bits for value */
 	xfs_rtword_t	want;		/* mask for "good" values */
 	xfs_rtword_t	wdiff;		/* difference from wanted value */
+	xfs_rtword_t	incore;
 	unsigned int	word;		/* word number in the buffer */
 
 	/*
@@ -297,14 +287,14 @@ xfs_rtfind_forw(
 	 * Get the first word's index & point to it.
 	 */
 	word = xfs_rtx_to_rbmword(mp, start);
-	b = xfs_rbmblock_wordptr(bp, word);
 	bit = (int)(start & (XFS_NBWORD - 1));
 	len = limit - start + 1;
 	/*
 	 * Compute match value, based on the bit at start: if 1 (free)
 	 * then all-ones, else all-zeroes.
 	 */
-	want = (*b & ((xfs_rtword_t)1 << bit)) ? -1 : 0;
+	incore = xfs_rtbitmap_getword(bp, word);
+	want = (incore & ((xfs_rtword_t)1 << bit)) ? -1 : 0;
 	/*
 	 * If the starting position is not word-aligned, deal with the
 	 * partial word.
@@ -320,7 +310,7 @@ xfs_rtfind_forw(
 		 * Calculate the difference between the value there
 		 * and what we're looking for.
 		 */
-		if ((wdiff = (*b ^ want) & mask)) {
+		if ((wdiff = (incore ^ want) & mask)) {
 			/*
 			 * Different.  Mark where we are and return.
 			 */
@@ -345,12 +335,6 @@ xfs_rtfind_forw(
 			}
 
 			word = 0;
-			b = xfs_rbmblock_wordptr(bp, word);
-		} else {
-			/*
-			 * Go on to the previous word in the buffer.
-			 */
-			b++;
 		}
 	} else {
 		/*
@@ -366,7 +350,8 @@ xfs_rtfind_forw(
 		/*
 		 * Compute difference between actual and desired value.
 		 */
-		if ((wdiff = *b ^ want)) {
+		incore = xfs_rtbitmap_getword(bp, word);
+		if ((wdiff = incore ^ want)) {
 			/*
 			 * Different, mark where we are and return.
 			 */
@@ -391,12 +376,6 @@ xfs_rtfind_forw(
 			}
 
 			word = 0;
-			b = xfs_rbmblock_wordptr(bp, word);
-		} else {
-			/*
-			 * Go on to the next word in the buffer.
-			 */
-			b++;
 		}
 	}
 	/*
@@ -411,7 +390,8 @@ xfs_rtfind_forw(
 		/*
 		 * Compute difference between actual and desired value.
 		 */
-		if ((wdiff = (*b ^ want) & mask)) {
+		incore = xfs_rtbitmap_getword(bp, word);
+		if ((wdiff = (incore ^ want) & mask)) {
 			/*
 			 * Different, mark where we are and return.
 			 */
@@ -566,15 +546,14 @@ xfs_rtmodify_range(
 	xfs_rtxlen_t	len,		/* length of extent to modify */
 	int		val)		/* 1 for free, 0 for allocated */
 {
-	xfs_rtword_t	*b;		/* current word in buffer */
 	int		bit;		/* bit number in the word */
 	xfs_fileoff_t	block;		/* bitmap block number */
 	struct xfs_buf	*bp;		/* buf for the block */
 	int		error;		/* error value */
-	xfs_rtword_t	*first;		/* first used word in the buffer */
 	int		i;		/* current bit number rel. to start */
 	int		lastbit;	/* last useful bit in word */
 	xfs_rtword_t	mask;		/* mask o frelevant bits for value */
+	xfs_rtword_t	incore;
 	unsigned int	firstword;	/* first word used in the buffer */
 	unsigned int	word;		/* word number in the buffer */
 
@@ -594,7 +573,6 @@ xfs_rtmodify_range(
 	 * Compute the starting word's address, and starting bit.
 	 */
 	firstword = word = xfs_rtx_to_rbmword(mp, start);
-	first = b = xfs_rbmblock_wordptr(bp, word);
 	bit = (int)(start & (XFS_NBWORD - 1));
 	/*
 	 * 0 (allocated) => all zeroes; 1 (free) => all ones.
@@ -613,10 +591,12 @@ xfs_rtmodify_range(
 		/*
 		 * Set/clear the active bits.
 		 */
+		incore = xfs_rtbitmap_getword(bp, word);
 		if (val)
-			*b |= mask;
+			incore |= mask;
 		else
-			*b &= ~mask;
+			incore &= ~mask;
+		xfs_rtbitmap_setword(bp, word, incore);
 		i = lastbit - bit;
 		/*
 		 * Go on to the next block if that's where the next word is
@@ -634,12 +614,6 @@ xfs_rtmodify_range(
 			}
 
 			firstword = word = 0;
-			first = b = xfs_rbmblock_wordptr(bp, word);
-		} else {
-			/*
-			 * Go on to the next word in the buffer
-			 */
-			b++;
 		}
 	} else {
 		/*
@@ -655,7 +629,7 @@ xfs_rtmodify_range(
 		/*
 		 * Set the word value correctly.
 		 */
-		*b = val;
+		xfs_rtbitmap_setword(bp, word, val);
 		i += XFS_NBWORD;
 		/*
 		 * Go on to the next block if that's where the next word is
@@ -673,12 +647,6 @@ xfs_rtmodify_range(
 			}
 
 			firstword = word = 0;
-			first = b = xfs_rbmblock_wordptr(bp, word);
-		} else {
-			/*
-			 * Go on to the next word in the buffer
-			 */
-			b++;
 		}
 	}
 	/*
@@ -693,17 +661,18 @@ xfs_rtmodify_range(
 		/*
 		 * Set/clear the active bits.
 		 */
+		incore = xfs_rtbitmap_getword(bp, word);
 		if (val)
-			*b |= mask;
+			incore |= mask;
 		else
-			*b &= ~mask;
+			incore &= ~mask;
+		xfs_rtbitmap_setword(bp, word, incore);
 		word++;
-		b++;
 	}
 	/*
 	 * Log any remaining changed bytes.
 	 */
-	if (b > first)
+	if (word > firstword)
 		xfs_trans_log_rtbitmap(tp, bp, firstword, word);
 	return 0;
 }
@@ -798,7 +767,6 @@ xfs_rtcheck_range(
 	xfs_rtxnum_t	*new,		/* out: first rtext not matching */
 	int		*stat)		/* out: 1 for matches, 0 for not */
 {
-	xfs_rtword_t	*b;		/* current word in buffer */
 	int		bit;		/* bit number in the word */
 	xfs_fileoff_t	block;		/* bitmap block number */
 	struct xfs_buf	*bp;		/* buf for the block */
@@ -807,6 +775,7 @@ xfs_rtcheck_range(
 	xfs_rtxnum_t	lastbit;	/* last useful bit in word */
 	xfs_rtword_t	mask;		/* mask of relevant bits for value */
 	xfs_rtword_t	wdiff;		/* difference from wanted value */
+	xfs_rtword_t	incore;
 	unsigned int	word;		/* word number in the buffer */
 
 	/*
@@ -825,7 +794,6 @@ xfs_rtcheck_range(
 	 * Compute the starting word's address, and starting bit.
 	 */
 	word = xfs_rtx_to_rbmword(mp, start);
-	b = xfs_rbmblock_wordptr(bp, word);
 	bit = (int)(start & (XFS_NBWORD - 1));
 	/*
 	 * 0 (allocated) => all zero's; 1 (free) => all one's.
@@ -847,7 +815,8 @@ xfs_rtcheck_range(
 		/*
 		 * Compute difference between actual and desired value.
 		 */
-		if ((wdiff = (*b ^ val) & mask)) {
+		incore = xfs_rtbitmap_getword(bp, word);
+		if ((wdiff = (incore ^ val) & mask)) {
 			/*
 			 * Different, compute first wrong bit and return.
 			 */
@@ -873,12 +842,6 @@ xfs_rtcheck_range(
 			}
 
 			word = 0;
-			b = xfs_rbmblock_wordptr(bp, word);
-		} else {
-			/*
-			 * Go on to the next word in the buffer.
-			 */
-			b++;
 		}
 	} else {
 		/*
@@ -894,7 +857,8 @@ xfs_rtcheck_range(
 		/*
 		 * Compute difference between actual and desired value.
 		 */
-		if ((wdiff = *b ^ val)) {
+		incore = xfs_rtbitmap_getword(bp, word);
+		if ((wdiff = incore ^ val)) {
 			/*
 			 * Different, compute first wrong bit and return.
 			 */
@@ -920,12 +884,6 @@ xfs_rtcheck_range(
 			}
 
 			word = 0;
-			b = xfs_rbmblock_wordptr(bp, word);
-		} else {
-			/*
-			 * Go on to the next word in the buffer.
-			 */
-			b++;
 		}
 	}
 	/*
@@ -940,7 +898,8 @@ xfs_rtcheck_range(
 		/*
 		 * Compute difference between actual and desired value.
 		 */
-		if ((wdiff = (*b ^ val) & mask)) {
+		incore = xfs_rtbitmap_getword(bp, word);
+		if ((wdiff = (incore ^ val) & mask)) {
 			/*
 			 * Different, compute first wrong bit and return.
 			 */
diff --git a/libxfs/xfs_rtbitmap.h b/libxfs/xfs_rtbitmap.h
index 618c96468..02ee57f87 100644
--- a/libxfs/xfs_rtbitmap.h
+++ b/libxfs/xfs_rtbitmap.h
@@ -162,16 +162,39 @@ xfs_rbmblock_to_rtx(
 }
 
 /* Return a pointer to a bitmap word within a rt bitmap block. */
-static inline xfs_rtword_t *
+static inline union xfs_rtword_raw *
 xfs_rbmblock_wordptr(
 	struct xfs_buf		*bp,
 	unsigned int		index)
 {
-	xfs_rtword_t		*words = bp->b_addr;
+	union xfs_rtword_raw	*words = bp->b_addr;
 
 	return words + index;
 }
 
+/* Convert an ondisk bitmap word to its incore representation. */
+static inline xfs_rtword_t
+xfs_rtbitmap_getword(
+	struct xfs_buf		*bp,
+	unsigned int		index)
+{
+	union xfs_rtword_raw	*word = xfs_rbmblock_wordptr(bp, index);
+
+	return word->old;
+}
+
+/* Set an ondisk bitmap word from an incore representation. */
+static inline void
+xfs_rtbitmap_setword(
+	struct xfs_buf		*bp,
+	unsigned int		index,
+	xfs_rtword_t		value)
+{
+	union xfs_rtword_raw	*word = xfs_rbmblock_wordptr(bp, index);
+
+	word->old = value;
+}
+
 /*
  * Convert a rt extent length and rt bitmap block number to a xfs_suminfo_t
  * offset within the rt summary file.
