fs/adfs: map: break up adfs_read_map()

Split up adfs_read_map() into separate helpers to layout the map,
read the map, and release the map buffers.

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 c322d37e8f9177e702d1def63a9140431fe74ad3..4b677cd5d015781ef36f64f0abbebfb9a2c424eb 100644 (file)
--- a/fs/adfs/map.c
+++ b/fs/adfs/map.c
@@ -331,12 +331,63 @@ static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)
        return crosscheck == 0xff && zonecheck;
 }
 
+/*
+ * Layout the map - the first zone contains a copy of the disc record,
+ * and the last zone must be limited to the size of the filesystem.
+ */
+static void adfs_map_layout(struct adfs_discmap *dm, unsigned int nzones,
+                           struct adfs_discrecord *dr)
+{
+       unsigned int zone, zone_size;
+       u64 size;
+
+       zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
+
+       dm[0].dm_bh       = NULL;
+       dm[0].dm_startblk = 0;
+       dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
+       dm[0].dm_endbit   = zone_size;
+
+       for (zone = 1; zone < nzones; zone++) {
+               dm[zone].dm_bh       = NULL;
+               dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
+               dm[zone].dm_startbit = 0;
+               dm[zone].dm_endbit   = zone_size;
+       }
+
+       size = adfs_disc_size(dr) >> dr->log2bpmb;
+       size -= (nzones - 1) * zone_size - ADFS_DR_SIZE_BITS;
+       dm[nzones - 1].dm_endbit = size;
+}
+
+static int adfs_map_read(struct adfs_discmap *dm, struct super_block *sb,
+                        unsigned int map_addr, unsigned int nzones)
+{
+       unsigned int zone;
+
+       for (zone = 0; zone < nzones; zone++) {
+               dm[zone].dm_bh = sb_bread(sb, map_addr + zone);
+               if (!dm[zone].dm_bh)
+                       return -EIO;
+       }
+
+       return 0;
+}
+
+static void adfs_map_relse(struct adfs_discmap *dm, unsigned int nzones)
+{
+       unsigned int zone;
+
+       for (zone = 0; zone < nzones; zone++)
+               brelse(dm[zone].dm_bh);
+}
+
 struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
 {
+       struct adfs_sb_info *asb = ADFS_SB(sb);
        struct adfs_discmap *dm;
        unsigned int map_addr, zone_size, nzones;
-       int i, zone;
-       struct adfs_sb_info *asb = ADFS_SB(sb);
+       int ret;
 
        nzones    = asb->s_map_size;
        zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
@@ -352,34 +403,21 @@ struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecor
                return ERR_PTR(-ENOMEM);
        }
 
-       for (zone = 0; zone < nzones; zone++, map_addr++) {
-               dm[zone].dm_startbit = 0;
-               dm[zone].dm_endbit   = zone_size;
-               dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
-               dm[zone].dm_bh       = sb_bread(sb, map_addr);
+       adfs_map_layout(dm, nzones, dr);
 
-               if (!dm[zone].dm_bh) {
-                       adfs_error(sb, "unable to read map");
-                       goto error_free;
-               }
+       ret = adfs_map_read(dm, sb, map_addr, nzones);
+       if (ret) {
+               adfs_error(sb, "unable to read map");
+               goto error_free;
        }
 
-       /* adjust the limits for the first and last map zones */
-       i = zone - 1;
-       dm[0].dm_startblk = 0;
-       dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
-       dm[i].dm_endbit   = (adfs_disc_size(dr) >> dr->log2bpmb) +
-                           (ADFS_DR_SIZE_BITS - i * zone_size);
-
        if (adfs_checkmap(sb, dm))
                return dm;
 
        adfs_error(sb, "map corrupted");
 
 error_free:
-       while (--zone >= 0)
-               brelse(dm[zone].dm_bh);
-
+       adfs_map_relse(dm, nzones);
        kfree(dm);
        return ERR_PTR(-EIO);
 }