3 files changed, 13 insertions, 86 deletions

diff --git a/fs/xfs/xfs_bit.c b/fs/xfs/xfs_bit.c
index 1afe07f67e3b..fab0b6d5a41b 100644
--- a/fs/xfs/xfs_bit.c
+++ b/fs/xfs/xfs_bit.c
@@ -66,44 +66,6 @@ static const char xfs_highbit[256] = {
 #endif
 
 /*
- * Count of bits set in byte, 0..8.
- */
-static const char xfs_countbit[256] = {
-        0, 1, 1, 2, 1, 2, 2, 3,                 /* 00 .. 07 */
-        1, 2, 2, 3, 2, 3, 3, 4,                 /* 08 .. 0f */
-        1, 2, 2, 3, 2, 3, 3, 4,                 /* 10 .. 17 */
-        2, 3, 3, 4, 3, 4, 4, 5,                 /* 18 .. 1f */
-        1, 2, 2, 3, 2, 3, 3, 4,                 /* 20 .. 27 */
-        2, 3, 3, 4, 3, 4, 4, 5,                 /* 28 .. 2f */
-        2, 3, 3, 4, 3, 4, 4, 5,                 /* 30 .. 37 */
-        3, 4, 4, 5, 4, 5, 5, 6,                 /* 38 .. 3f */
-        1, 2, 2, 3, 2, 3, 3, 4,                 /* 40 .. 47 */
-        2, 3, 3, 4, 3, 4, 4, 5,                 /* 48 .. 4f */
-        2, 3, 3, 4, 3, 4, 4, 5,                 /* 50 .. 57 */
-        3, 4, 4, 5, 4, 5, 5, 6,                 /* 58 .. 5f */
-        2, 3, 3, 4, 3, 4, 4, 5,                 /* 60 .. 67 */
-        3, 4, 4, 5, 4, 5, 5, 6,                 /* 68 .. 6f */
-        3, 4, 4, 5, 4, 5, 5, 6,                 /* 70 .. 77 */
-        4, 5, 5, 6, 5, 6, 6, 7,                 /* 78 .. 7f */
-        1, 2, 2, 3, 2, 3, 3, 4,                 /* 80 .. 87 */
-        2, 3, 3, 4, 3, 4, 4, 5,                 /* 88 .. 8f */
-        2, 3, 3, 4, 3, 4, 4, 5,                 /* 90 .. 97 */
-        3, 4, 4, 5, 4, 5, 5, 6,                 /* 98 .. 9f */
-        2, 3, 3, 4, 3, 4, 4, 5,                 /* a0 .. a7 */
-        3, 4, 4, 5, 4, 5, 5, 6,                 /* a8 .. af */
-        3, 4, 4, 5, 4, 5, 5, 6,                 /* b0 .. b7 */
-        4, 5, 5, 6, 5, 6, 6, 7,                 /* b8 .. bf */
-        2, 3, 3, 4, 3, 4, 4, 5,                 /* c0 .. c7 */
-        3, 4, 4, 5, 4, 5, 5, 6,                 /* c8 .. cf */
-        3, 4, 4, 5, 4, 5, 5, 6,                 /* d0 .. d7 */
-        4, 5, 5, 6, 5, 6, 6, 7,                 /* d8 .. df */
-        3, 4, 4, 5, 4, 5, 5, 6,                 /* e0 .. e7 */
-        4, 5, 5, 6, 5, 6, 6, 7,                 /* e8 .. ef */
-        4, 5, 5, 6, 5, 6, 6, 7,                 /* f0 .. f7 */
-        5, 6, 6, 7, 6, 7, 7, 8,                 /* f8 .. ff */
-};
-
-/*
  * xfs_highbit32: get high bit set out of 32-bit argument, -1 if none set.
  */
 inline int
@@ -167,56 +129,21 @@ xfs_highbit64(
 
 
 /*
- * Count the number of bits set in the bitmap starting with bit
- * start_bit.  Size is the size of the bitmap in words.
- *
- * Do the counting by mapping a byte value to the number of set
- * bits for that value using the xfs_countbit array, i.e.
- * xfs_countbit[0] == 0, xfs_countbit[1] == 1, xfs_countbit[2] == 1,
- * xfs_countbit[3] == 2, etc.
+ * Return whether bitmap is empty.
+ * Size is number of words in the bitmap, which is padded to word boundary
+ * Returns 1 for empty, 0 for non-empty.
  */
 int
-xfs_count_bits(uint *map, uint size, uint start_bit)
+xfs_bitmap_empty(uint *map, uint size)
 {
-        register int    bits;
-        register unsigned char  *bytep;
-        register unsigned char  *end_map;
-        int             byte_bit;
-
-        bits = 0;
-        end_map = (char*)(map + size);
-        bytep = (char*)(map + (start_bit & ~0x7));
-        byte_bit = start_bit & 0x7;
-
-        /*
-         * If the caller fell off the end of the map, return 0.
-         */
-        if (bytep >= end_map) {
-                return (0);
-        }
-
-        /*
-         * If start_bit is not byte aligned, then process the
-         * first byte separately.
-         */
-        if (byte_bit != 0) {
-                /*
-                 * Shift off the bits we don't want to look at,
-                 * before indexing into xfs_countbit.
-                 */
-                bits += xfs_countbit[(*bytep >> byte_bit)];
-                bytep++;
-        }
+        uint i;
+        uint ret = 0;
 
-        /*
-         * Count the bits in each byte until the end of the bitmap.
-         */
-        while (bytep < end_map) {
-                bits += xfs_countbit[*bytep];
-                bytep++;
+        for (i = 0; i < size; i++) {
+                ret |= map[i];
         }
 
-        return (bits);
+        return (ret == 0);
 }
 
 /*
diff --git a/fs/xfs/xfs_bit.h b/fs/xfs/xfs_bit.h
index 0bbe56817542..082641a9782c 100644
--- a/fs/xfs/xfs_bit.h
+++ b/fs/xfs/xfs_bit.h
@@ -55,8 +55,8 @@ extern int xfs_lowbit64(__uint64_t v);
 /* Get high bit set out of 64-bit argument, -1 if none set */
 extern int xfs_highbit64(__uint64_t);
 
-/* Count set bits in map starting with start_bit */
-extern int xfs_count_bits(uint *map, uint size, uint start_bit);
+/* Return whether bitmap is empty (1 == empty) */
+extern int xfs_bitmap_empty(uint *map, uint size);
 
 /* Count continuous one bits in map starting with start_bit */
 extern int xfs_contig_bits(uint *map, uint size, uint start_bit);
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 6c1bddc04e31..b0667cb27d66 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -580,8 +580,8 @@ xfs_buf_item_unlock(
          * If the buf item isn't tracking any data, free it.
          * Otherwise, if XFS_BLI_HOLD is set clear it.
          */
-        if (xfs_count_bits(bip->bli_format.blf_data_map,
-                              bip->bli_format.blf_map_size, 0) == 0) {
+        if (xfs_bitmap_empty(bip->bli_format.blf_data_map,
+                             bip->bli_format.blf_map_size)) {
                 xfs_buf_item_relse(bp);
         } else if (hold) {
                 bip->bli_flags &= ~XFS_BLI_HOLD;