From 7bf72edee614e10b8d470c40a326f47bfdd69992 Mon Sep 17 00:00:00 2001 From: Mark Fasheh Date: Wed, 3 May 2006 17:46:50 -0700 Subject: 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 --- fs/ocfs2/suballoc.c | 114 +++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 94 insertions(+), 20 deletions(-) (limited to 'fs') diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c index 195523090c8..7ac68cac041 100644 --- a/fs/ocfs2/suballoc.c +++ b/fs/ocfs2/suballoc.c @@ -85,11 +85,6 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb, 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 @@ static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl) 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_test_bg_bit_allocatable(struct buffer_head *bg_bh, 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 @@ static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb, 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 @@ static int ocfs2_cluster_group_search(struct inode *inode, { 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 @@ static int ocfs2_block_group_search(struct inode *inode, 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 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac, 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 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac, 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 @@ static int ocfs2_free_suballoc_bits(struct ocfs2_journal_handle *handle, } 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)); -- cgit v1.2.3