]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - fs/ext2/balloc.c
fs/ext2: use BUG_ON
[linux-2.6-omap-h63xx.git] / fs / ext2 / balloc.c
index 18a42de25b556dd2b311f06619678c4bc06c66e7..c834f512dce5fc21026a2345ca6366d3092c2e77 100644 (file)
@@ -69,68 +69,92 @@ struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
        return desc + offset;
 }
 
-static inline int
-block_in_use(unsigned long block, struct super_block *sb, unsigned char *map)
+static int ext2_valid_block_bitmap(struct super_block *sb,
+                                       struct ext2_group_desc *desc,
+                                       unsigned int block_group,
+                                       struct buffer_head *bh)
 {
-       return ext2_test_bit ((block -
-               le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block)) %
-                        EXT2_BLOCKS_PER_GROUP(sb), map);
+       ext2_grpblk_t offset;
+       ext2_grpblk_t next_zero_bit;
+       ext2_fsblk_t bitmap_blk;
+       ext2_fsblk_t group_first_block;
+
+       group_first_block = ext2_group_first_block_no(sb, block_group);
+
+       /* check whether block bitmap block number is set */
+       bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
+       offset = bitmap_blk - group_first_block;
+       if (!ext2_test_bit(offset, bh->b_data))
+               /* bad block bitmap */
+               goto err_out;
+
+       /* check whether the inode bitmap block number is set */
+       bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap);
+       offset = bitmap_blk - group_first_block;
+       if (!ext2_test_bit(offset, bh->b_data))
+               /* bad block bitmap */
+               goto err_out;
+
+       /* check whether the inode table block number is set */
+       bitmap_blk = le32_to_cpu(desc->bg_inode_table);
+       offset = bitmap_blk - group_first_block;
+       next_zero_bit = ext2_find_next_zero_bit(bh->b_data,
+                               offset + EXT2_SB(sb)->s_itb_per_group,
+                               offset);
+       if (next_zero_bit >= offset + EXT2_SB(sb)->s_itb_per_group)
+               /* good bitmap for inode tables */
+               return 1;
+
+err_out:
+       ext2_error(sb, __FUNCTION__,
+                       "Invalid block bitmap - "
+                       "block_group = %d, block = %lu",
+                       block_group, bitmap_blk);
+       return 0;
 }
 
 /*
- * Read the bitmap for a given block_group, reading into the specified 
- * slot in the superblock's bitmap cache.
+ * Read the bitmap for a given block_group,and validate the
+ * bits for block/inode/inode tables are set in the bitmaps
  *
  * Return buffer_head on success or NULL in case of failure.
  */
 static struct buffer_head *
 read_block_bitmap(struct super_block *sb, unsigned int block_group)
 {
-       int i;
        struct ext2_group_desc * desc;
        struct buffer_head * bh = NULL;
-       unsigned int bitmap_blk;
+       ext2_fsblk_t bitmap_blk;
 
-       desc = ext2_get_group_desc (sb, block_group, NULL);
+       desc = ext2_get_group_desc(sb, block_group, NULL);
        if (!desc)
                return NULL;
        bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
-       bh = sb_bread(sb, bitmap_blk);
-       if (!bh)
-               ext2_error (sb, __FUNCTION__,
+       bh = sb_getblk(sb, bitmap_blk);
+       if (unlikely(!bh)) {
+               ext2_error(sb, __FUNCTION__,
                            "Cannot read block bitmap - "
                            "block_group = %d, block_bitmap = %u",
                            block_group, le32_to_cpu(desc->bg_block_bitmap));
-
-       /* check whether block bitmap block number is set */
-       if (!block_in_use(bitmap_blk, sb, bh->b_data)) {
-               /* bad block bitmap */
-               goto error_out;
+               return NULL;
        }
-       /* check whether the inode bitmap block number is set */
-       bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap);
-       if (!block_in_use(bitmap_blk, sb, bh->b_data)) {
-               /* bad block bitmap */
-               goto error_out;
+       if (likely(bh_uptodate_or_lock(bh)))
+               return bh;
+
+       if (bh_submit_read(bh) < 0) {
+               brelse(bh);
+               ext2_error(sb, __FUNCTION__,
+                           "Cannot read block bitmap - "
+                           "block_group = %d, block_bitmap = %u",
+                           block_group, le32_to_cpu(desc->bg_block_bitmap));
+               return NULL;
        }
-       /* check whether the inode table block number is set */
-       bitmap_blk = le32_to_cpu(desc->bg_inode_table);
-       for (i = 0; i < EXT2_SB(sb)->s_itb_per_group; i++, bitmap_blk++) {
-               if (!block_in_use(bitmap_blk, sb, bh->b_data)) {
-                       /* bad block bitmap */
-                       goto error_out;
-               }
+       if (!ext2_valid_block_bitmap(sb, desc, block_group, bh)) {
+               brelse(bh);
+               return NULL;
        }
 
        return bh;
-
-error_out:
-       brelse(bh);
-       ext2_error(sb, __FUNCTION__,
-                       "Invalid block bitmap - "
-                       "block_group = %d, block = %u",
-                       block_group, bitmap_blk);
-       return NULL;
 }
 
 static void release_blocks(struct super_block *sb, int count)
@@ -221,8 +245,7 @@ restart:
                prev = rsv;
        }
        printk("Window map complete.\n");
-       if (bad)
-               BUG();
+       BUG_ON(bad);
 }
 #define rsv_window_dump(root, verbose) \
        __rsv_window_dump((root), (verbose), __FUNCTION__)
@@ -513,11 +536,13 @@ do_more:
            in_range (block, le32_to_cpu(desc->bg_inode_table),
                      sbi->s_itb_per_group) ||
            in_range (block + count - 1, le32_to_cpu(desc->bg_inode_table),
-                     sbi->s_itb_per_group))
+                     sbi->s_itb_per_group)) {
                ext2_error (sb, "ext2_free_blocks",
                            "Freeing blocks in system zones - "
                            "Block = %lu, count = %lu",
                            block, count);
+               goto error_return;
+       }
 
        for (i = 0, group_freed = 0; i < count; i++) {
                if (!ext2_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
@@ -1289,8 +1314,8 @@ retry_alloc:
        smp_rmb();
 
        /*
-        * Now search the rest of the groups.  We assume that 
-        * i and gdp correctly point to the last group visited.
+        * Now search the rest of the groups.  We assume that
+        * group_no and gdp correctly point to the last group visited.
         */
        for (bgi = 0; bgi < ngroups; bgi++) {
                group_no++;
@@ -1350,11 +1375,13 @@ allocated:
            in_range(ret_block, le32_to_cpu(gdp->bg_inode_table),
                      EXT2_SB(sb)->s_itb_per_group) ||
            in_range(ret_block + num - 1, le32_to_cpu(gdp->bg_inode_table),
-                     EXT2_SB(sb)->s_itb_per_group))
+                     EXT2_SB(sb)->s_itb_per_group)) {
                ext2_error(sb, "ext2_new_blocks",
                            "Allocating block in system zone - "
                            "blocks from "E2FSBLK", length %lu",
                            ret_block, num);
+               goto out;
+       }
 
        performed_allocation = 1;
 
@@ -1461,7 +1488,6 @@ unsigned long ext2_count_free_blocks (struct super_block * sb)
 #endif
 }
 
-
 static inline int test_root(int a, int b)
 {
        int num = b;
@@ -1506,9 +1532,6 @@ int ext2_bg_has_super(struct super_block *sb, int group)
  */
 unsigned long ext2_bg_num_gdb(struct super_block *sb, int group)
 {
-       if (EXT2_HAS_RO_COMPAT_FEATURE(sb,EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)&&
-           !ext2_group_sparse(group))
-               return 0;
-       return EXT2_SB(sb)->s_gdb_count;
+       return ext2_bg_has_super(sb, group) ? EXT2_SB(sb)->s_gdb_count : 0;
 }