X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Fext2%2Fballoc.c;h=10bb02c3f25cfcdee98897b6d7efe96e5f3ae6a1;hb=34b4a8731f50fb6fe772f1e47432bfb1da1f4edd;hp=18a42de25b556dd2b311f06619678c4bc06c66e7;hpb=fe2520094d88018423dfc42b3cd0015f74e8adea;p=linux-2.6

diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
index 18a42de25b..10bb02c3f2 100644
--- a/fs/ext2/balloc.c
+++ b/fs/ext2/balloc.c
@@ -69,68 +69,93 @@ 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, __func__,
+			"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, __func__,
 			    "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;
-	}
-	/* 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;
+		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 (likely(bh_uptodate_or_lock(bh)))
+		return bh;
+
+	if (bh_submit_read(bh) < 0) {
+		brelse(bh);
+		ext2_error(sb, __func__,
+			    "Cannot read block bitmap - "
+			    "block_group = %d, block_bitmap = %u",
+			    block_group, le32_to_cpu(desc->bg_block_bitmap));
+		return NULL;
 	}
 
+	ext2_valid_block_bitmap(sb, desc, block_group, bh);
+	/*
+	 * file system mounted not to panic on error, continue with corrupt
+	 * bitmap
+	 */
 	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)
@@ -221,11 +246,10 @@ 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__)
+	__rsv_window_dump((root), (verbose), __func__)
 #else
 #define rsv_window_dump(root, verbose) do {} while (0)
 #endif
@@ -513,16 +537,18 @@ 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),
 						bit + i, bitmap_bh->b_data)) {
-			ext2_error(sb, __FUNCTION__,
+			ext2_error(sb, __func__,
 				"bit already cleared for block %lu", block + i);
 		} else {
 			group_freed++;
@@ -1289,8 +1315,8 @@ 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 +1376,18 @@ 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);
+		/*
+		 * ext2_try_to_allocate marked the blocks we allocated as in
+		 * use.  So we may want to selectively mark some of the blocks
+		 * as free
+		 */
+		goto retry_alloc;
+	}
 
 	performed_allocation = 1;
 
@@ -1461,7 +1494,6 @@ 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 +1538,6 @@ 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;
 }