ocfs2: better group descriptor consistency checks
Try to catch corrupted group descriptors with some stronger checks placed in
a couple of strategic locations. Detect a failed resizefs and refuse to
allocate past what bitmap i_clusters allows.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 1955230..7ac68ca 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -85,11 +85,6 @@
u64 *bg_blkno);
static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
int nr);
-static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
- struct buffer_head *bg_bh,
- unsigned int bits_wanted,
- u16 *bit_off,
- u16 *bits_found);
static inline int ocfs2_block_group_set_bits(struct ocfs2_journal_handle *handle,
struct inode *alloc_inode,
struct ocfs2_group_desc *bg,
@@ -143,6 +138,64 @@
return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
}
+/* somewhat more expensive than our other checks, so use sparingly. */
+static int ocfs2_check_group_descriptor(struct super_block *sb,
+ struct ocfs2_dinode *di,
+ struct ocfs2_group_desc *gd)
+{
+ unsigned int max_bits;
+
+ if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
+ OCFS2_RO_ON_INVALID_GROUP_DESC(sb, gd);
+ return -EIO;
+ }
+
+ if (di->i_blkno != gd->bg_parent_dinode) {
+ ocfs2_error(sb, "Group descriptor # %llu has bad parent "
+ "pointer (%llu, expected %llu)",
+ (unsigned long long)le64_to_cpu(gd->bg_blkno),
+ (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
+ (unsigned long long)le64_to_cpu(di->i_blkno));
+ return -EIO;
+ }
+
+ max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
+ if (le16_to_cpu(gd->bg_bits) > max_bits) {
+ ocfs2_error(sb, "Group descriptor # %llu has bit count of %u",
+ (unsigned long long)le64_to_cpu(gd->bg_blkno),
+ le16_to_cpu(gd->bg_bits));
+ return -EIO;
+ }
+
+ if (le16_to_cpu(gd->bg_chain) >=
+ le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) {
+ ocfs2_error(sb, "Group descriptor # %llu has bad chain %u",
+ (unsigned long long)le64_to_cpu(gd->bg_blkno),
+ le16_to_cpu(gd->bg_chain));
+ return -EIO;
+ }
+
+ if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
+ ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
+ "claims that %u are free",
+ (unsigned long long)le64_to_cpu(gd->bg_blkno),
+ le16_to_cpu(gd->bg_bits),
+ le16_to_cpu(gd->bg_free_bits_count));
+ return -EIO;
+ }
+
+ if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
+ ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
+ "max bitmap bits of %u",
+ (unsigned long long)le64_to_cpu(gd->bg_blkno),
+ le16_to_cpu(gd->bg_bits),
+ 8 * le16_to_cpu(gd->bg_size));
+ return -EIO;
+ }
+
+ return 0;
+}
+
static int ocfs2_block_group_fill(struct ocfs2_journal_handle *handle,
struct inode *alloc_inode,
struct buffer_head *bg_bh,
@@ -663,6 +716,7 @@
static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
struct buffer_head *bg_bh,
unsigned int bits_wanted,
+ unsigned int total_bits,
u16 *bit_off,
u16 *bits_found)
{
@@ -679,10 +733,8 @@
found = start = best_offset = best_size = 0;
bitmap = bg->bg_bitmap;
- while((offset = ocfs2_find_next_zero_bit(bitmap,
- le16_to_cpu(bg->bg_bits),
- start)) != -1) {
- if (offset == le16_to_cpu(bg->bg_bits))
+ while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
+ if (offset == total_bits)
break;
if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
@@ -911,14 +963,35 @@
{
int search = -ENOSPC;
int ret;
- struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
+ struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
u16 tmp_off, tmp_found;
+ unsigned int max_bits, gd_cluster_off;
BUG_ON(!ocfs2_is_cluster_bitmap(inode));
- if (bg->bg_free_bits_count) {
+ if (gd->bg_free_bits_count) {
+ max_bits = le16_to_cpu(gd->bg_bits);
+
+ /* Tail groups in cluster bitmaps which aren't cpg
+ * aligned are prone to partial extention by a failed
+ * fs resize. If the file system resize never got to
+ * update the dinode cluster count, then we don't want
+ * to trust any clusters past it, regardless of what
+ * the group descriptor says. */
+ gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
+ le64_to_cpu(gd->bg_blkno));
+ if ((gd_cluster_off + max_bits) >
+ OCFS2_I(inode)->ip_clusters) {
+ max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
+ mlog(0, "Desc %llu, bg_bits %u, clusters %u, use %u\n",
+ (unsigned long long)le64_to_cpu(gd->bg_blkno),
+ le16_to_cpu(gd->bg_bits),
+ OCFS2_I(inode)->ip_clusters, max_bits);
+ }
+
ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
group_bh, bits_wanted,
+ max_bits,
&tmp_off, &tmp_found);
if (ret)
return ret;
@@ -951,6 +1024,7 @@
if (bg->bg_free_bits_count)
ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
group_bh, bits_wanted,
+ le16_to_cpu(bg->bg_bits),
bit_off, bits_found);
return ret;
@@ -988,9 +1062,9 @@
goto bail;
}
bg = (struct ocfs2_group_desc *) group_bh->b_data;
- if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
- OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
- status = -EIO;
+ status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
+ if (status) {
+ mlog_errno(status);
goto bail;
}
@@ -1018,9 +1092,9 @@
goto bail;
}
bg = (struct ocfs2_group_desc *) group_bh->b_data;
- if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
- OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
- status = -EIO;
+ status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
+ if (status) {
+ mlog_errno(status);
goto bail;
}
}
@@ -1494,9 +1568,9 @@
}
group = (struct ocfs2_group_desc *) group_bh->b_data;
- if (!OCFS2_IS_VALID_GROUP_DESC(group)) {
- OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, group);
- status = -EIO;
+ status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, group);
+ if (status) {
+ mlog_errno(status);
goto bail;
}
BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));