fs/adfs: map: use find_next_bit_le() rather than open coding it

Use find_next_bit_le() to find the end of a fragment in the map rather
than open-coding this functionality.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/adfs/map.c b/fs/adfs/map.c
index 55bd7c20158ccfdc713e288c9fa252a07a23cde3..9be0b47da19c0ac91db5067c7fede1ce7068adc9 100644 (file)
--- a/fs/adfs/map.c
+++ b/fs/adfs/map.c
@@ -72,50 +72,32 @@ static int lookup_zone(const struct adfs_discmap *dm, const unsigned int idlen,
        const u32 idmask = (1 << idlen) - 1;
        unsigned char *map = dm->dm_bh->b_data;
        unsigned int start = dm->dm_startbit;
-       unsigned int mapptr;
+       unsigned int fragend;
        u32 frag;
 
        do {
                frag = GET_FRAG_ID(map, start, idmask);
-               mapptr = start + idlen;
-
-               /*
-                * find end of fragment
-                */
-               {
-                       __le32 *_map = (__le32 *)map;
-                       u32 v = le32_to_cpu(_map[mapptr >> 5]) >> (mapptr & 31);
-                       while (v == 0) {
-                               mapptr = (mapptr & ~31) + 32;
-                               if (mapptr >= endbit)
-                                       goto error;
-                               v = le32_to_cpu(_map[mapptr >> 5]);
-                       }
-
-                       mapptr += 1 + ffz(~v);
+
+               fragend = find_next_bit_le(map, endbit, start + idlen);
+               if (fragend >= endbit)
+                       goto error;
+
+               if (frag == frag_id) {
+                       unsigned int length = fragend + 1 - start;
+
+                       if (*offset < length)
+                               return start + *offset;
+                       *offset -= length;
                }
 
-               if (frag == frag_id)
-                       goto found;
-again:
-               start = mapptr;
-       } while (mapptr < endbit);
+               start = fragend + 1;
+       } while (start < endbit);
        return -1;
 
 error:
        printk(KERN_ERR "adfs: oversized fragment 0x%x at 0x%x-0x%x\n",
-               frag, start, mapptr);
+               frag, start, fragend);
        return -1;
-
-found:
-       {
-               int length = mapptr - start;
-               if (*offset >= length) {
-                       *offset -= length;
-                       goto again;
-               }
-       }
-       return start + *offset;
 }
 
 /*
@@ -132,7 +114,7 @@ scan_free_map(struct adfs_sb_info *asb, struct adfs_discmap *dm)
        const unsigned int frag_idlen = idlen <= 15 ? idlen : 15;
        const u32 idmask = (1 << frag_idlen) - 1;
        unsigned char *map = dm->dm_bh->b_data;
-       unsigned int start = 8, mapptr;
+       unsigned int start = 8, fragend;
        u32 frag;
        unsigned long total = 0;
 
@@ -151,29 +133,13 @@ scan_free_map(struct adfs_sb_info *asb, struct adfs_discmap *dm)
        do {
                start += frag;
 
-               /*
-                * get fragment id
-                */
                frag = GET_FRAG_ID(map, start, idmask);
-               mapptr = start + idlen;
-
-               /*
-                * find end of fragment
-                */
-               {
-                       __le32 *_map = (__le32 *)map;
-                       u32 v = le32_to_cpu(_map[mapptr >> 5]) >> (mapptr & 31);
-                       while (v == 0) {
-                               mapptr = (mapptr & ~31) + 32;
-                               if (mapptr >= endbit)
-                                       goto error;
-                               v = le32_to_cpu(_map[mapptr >> 5]);
-                       }
-
-                       mapptr += 1 + ffz(~v);
-               }
 
-               total += mapptr - start;
+               fragend = find_next_bit_le(map, endbit, start + idlen);
+               if (fragend >= endbit)
+                       goto error;
+
+               total += fragend + 1 - start;
        } while (frag >= idlen + 1);
 
        if (frag != 0)