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ocfs2: Validate metadata only when it's read from disk.

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Add an optional validation hook to ocfs2_read_blocks().  Now the
validation function is only called when a block was actually read off of
disk.  It is not called when the buffer was in cache.

We add a buffer state bit BH_NeedsValidate to flag these buffers.  It
must always be one higher than the last JBD2 buffer state bit.

The dinode, dirblock, extent_block, and xattr_block validators are
lifted to this scheme directly.  The group_descriptor validator needs to
be split into two pieces.  The first part only needs the gd buffer and
is passed to ocfs2_read_block().  The second part requires the dinode as
well, and is called every time.  It's only 3 compares, so it's tiny.
This also allows us to clean up the non-fatal gd check used by resize.c.
It now has no magic argument.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This commit is contained in:
Joel Becker
2008-11-13 14:49:19 -08:00
committed by Mark Fasheh
parent 4ae1d69bed
commit 970e4936d7
10 changed files with 149 additions and 97 deletions
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91
fs/ocfs2/suballoc.c
View File

@@ -145,14 +145,6 @@ 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);
}
int ocfs2_validate_group_descriptor(struct super_block *sb,
struct ocfs2_dinode *di,
struct buffer_head *bh,
int clean_error)
{
unsigned int max_bits;
struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
#define do_error(fmt, ...) \
do{ \
if (clean_error) \
@@ -161,6 +153,12 @@ int ocfs2_validate_group_descriptor(struct super_block *sb,
ocfs2_error(sb, fmt, ##__VA_ARGS__); \
} while (0)
static int ocfs2_validate_gd_self(struct super_block *sb,
struct buffer_head *bh,
int clean_error)
{
struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
do_error("Group descriptor #%llu has bad signature %.*s",
(unsigned long long)bh->b_blocknr, 7,
@@ -184,6 +182,35 @@ int ocfs2_validate_group_descriptor(struct super_block *sb,
return -EINVAL;
}
if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
do_error("Group descriptor #%llu has bit count %u but "
"claims that %u are free",
(unsigned long long)bh->b_blocknr,
le16_to_cpu(gd->bg_bits),
le16_to_cpu(gd->bg_free_bits_count));
return -EINVAL;
}
if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
do_error("Group descriptor #%llu has bit count %u but "
"max bitmap bits of %u",
(unsigned long long)bh->b_blocknr,
le16_to_cpu(gd->bg_bits),
8 * le16_to_cpu(gd->bg_size));
return -EINVAL;
}
return 0;
}
static int ocfs2_validate_gd_parent(struct super_block *sb,
struct ocfs2_dinode *di,
struct buffer_head *bh,
int clean_error)
{
unsigned int max_bits;
struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
if (di->i_blkno != gd->bg_parent_dinode) {
do_error("Group descriptor #%llu has bad parent "
"pointer (%llu, expected %llu)",
@@ -209,26 +236,35 @@ int ocfs2_validate_group_descriptor(struct super_block *sb,
return -EINVAL;
}
if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
do_error("Group descriptor #%llu has bit count %u but "
"claims that %u are free",
(unsigned long long)bh->b_blocknr,
le16_to_cpu(gd->bg_bits),
le16_to_cpu(gd->bg_free_bits_count));
return -EINVAL;
}
return 0;
}
if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
do_error("Group descriptor #%llu has bit count %u but "
"max bitmap bits of %u",
(unsigned long long)bh->b_blocknr,
le16_to_cpu(gd->bg_bits),
8 * le16_to_cpu(gd->bg_size));
return -EINVAL;
}
#undef do_error
return 0;
/*
* This version only prints errors. It does not fail the filesystem, and
* exists only for resize.
*/
int ocfs2_check_group_descriptor(struct super_block *sb,
struct ocfs2_dinode *di,
struct buffer_head *bh)
{
int rc;
rc = ocfs2_validate_gd_self(sb, bh, 1);
if (!rc)
rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
return rc;
}
static int ocfs2_validate_group_descriptor(struct super_block *sb,
struct buffer_head *bh)
{
mlog(0, "Validating group descriptor %llu\n",
(unsigned long long)bh->b_blocknr);
return ocfs2_validate_gd_self(sb, bh, 0);
}
int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
@@ -237,11 +273,12 @@ int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
int rc;
struct buffer_head *tmp = *bh;
rc = ocfs2_read_block(inode, gd_blkno, &tmp);
rc = ocfs2_read_block(inode, gd_blkno, &tmp,
ocfs2_validate_group_descriptor);
if (rc)
goto out;
rc = ocfs2_validate_group_descriptor(inode->i_sb, di, tmp, 0);
rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
if (rc) {
brelse(tmp);
goto out;