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-rw-r--r--fs/ext2/balloc.c98
1 files changed, 81 insertions, 17 deletions
diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
index 377ad172d74..e7b2bafa1dd 100644
--- a/fs/ext2/balloc.c
+++ b/fs/ext2/balloc.c
@@ -69,9 +69,53 @@ struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
return desc + offset;
}
+static int ext2_valid_block_bitmap(struct super_block *sb,
+ struct ext2_group_desc *desc,
+ unsigned int block_group,
+ struct buffer_head *bh)
+{
+ 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.
*/
@@ -80,17 +124,36 @@ read_block_bitmap(struct super_block *sb, unsigned int block_group)
{
struct ext2_group_desc * desc;
struct buffer_head * bh = NULL;
-
- desc = ext2_get_group_desc (sb, block_group, NULL);
+ ext2_fsblk_t bitmap_blk;
+
+ desc = ext2_get_group_desc(sb, block_group, NULL);
if (!desc)
- goto error_out;
- bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap));
- if (!bh)
- ext2_error (sb, "read_block_bitmap",
+ return NULL;
+ bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
+ 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));
+ return NULL;
+ }
+ 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));
-error_out:
+ return NULL;
+ }
+ if (!ext2_valid_block_bitmap(sb, desc, block_group, bh)) {
+ brelse(bh);
+ return NULL;
+ }
+
return bh;
}
@@ -474,11 +537,13 @@ 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),
@@ -1250,8 +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++;
@@ -1311,11 +1376,13 @@ 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;
@@ -1466,9 +1533,6 @@ 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;
}