mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-11 12:28:41 +08:00
ext4: Calculate and verify checksums for htree nodes
Calculate and verify the checksum for directory index tree (htree) node blocks. The checksum is stored in the last 4 bytes of the htree block and requires the dx_entry array to stop 1 dx_entry short of the end of the block. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
parent
7ac5990d5a
commit
dbe8944404
160
fs/ext4/namei.c
160
fs/ext4/namei.c
@ -188,6 +188,121 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
|
||||
static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
|
||||
struct inode *inode);
|
||||
|
||||
/* checksumming functions */
|
||||
static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
|
||||
struct ext4_dir_entry *dirent,
|
||||
int *offset)
|
||||
{
|
||||
struct ext4_dir_entry *dp;
|
||||
struct dx_root_info *root;
|
||||
int count_offset;
|
||||
|
||||
if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
|
||||
count_offset = 8;
|
||||
else if (le16_to_cpu(dirent->rec_len) == 12) {
|
||||
dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
|
||||
if (le16_to_cpu(dp->rec_len) !=
|
||||
EXT4_BLOCK_SIZE(inode->i_sb) - 12)
|
||||
return NULL;
|
||||
root = (struct dx_root_info *)(((void *)dp + 12));
|
||||
if (root->reserved_zero ||
|
||||
root->info_length != sizeof(struct dx_root_info))
|
||||
return NULL;
|
||||
count_offset = 32;
|
||||
} else
|
||||
return NULL;
|
||||
|
||||
if (offset)
|
||||
*offset = count_offset;
|
||||
return (struct dx_countlimit *)(((void *)dirent) + count_offset);
|
||||
}
|
||||
|
||||
static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
|
||||
int count_offset, int count, struct dx_tail *t)
|
||||
{
|
||||
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
|
||||
struct ext4_inode_info *ei = EXT4_I(inode);
|
||||
__u32 csum, old_csum;
|
||||
int size;
|
||||
|
||||
size = count_offset + (count * sizeof(struct dx_entry));
|
||||
old_csum = t->dt_checksum;
|
||||
t->dt_checksum = 0;
|
||||
csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
|
||||
csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
|
||||
t->dt_checksum = old_csum;
|
||||
|
||||
return cpu_to_le32(csum);
|
||||
}
|
||||
|
||||
static int ext4_dx_csum_verify(struct inode *inode,
|
||||
struct ext4_dir_entry *dirent)
|
||||
{
|
||||
struct dx_countlimit *c;
|
||||
struct dx_tail *t;
|
||||
int count_offset, limit, count;
|
||||
|
||||
if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
|
||||
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
|
||||
return 1;
|
||||
|
||||
c = get_dx_countlimit(inode, dirent, &count_offset);
|
||||
if (!c) {
|
||||
EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
|
||||
return 1;
|
||||
}
|
||||
limit = le16_to_cpu(c->limit);
|
||||
count = le16_to_cpu(c->count);
|
||||
if (count_offset + (limit * sizeof(struct dx_entry)) >
|
||||
EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
|
||||
EXT4_ERROR_INODE(inode, "metadata_csum set but no space for "
|
||||
"tree checksum found. Run e2fsck -D.");
|
||||
return 1;
|
||||
}
|
||||
t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
|
||||
|
||||
if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
|
||||
count, t))
|
||||
return 0;
|
||||
return 1;
|
||||
}
|
||||
|
||||
static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
|
||||
{
|
||||
struct dx_countlimit *c;
|
||||
struct dx_tail *t;
|
||||
int count_offset, limit, count;
|
||||
|
||||
if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
|
||||
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
|
||||
return;
|
||||
|
||||
c = get_dx_countlimit(inode, dirent, &count_offset);
|
||||
if (!c) {
|
||||
EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
|
||||
return;
|
||||
}
|
||||
limit = le16_to_cpu(c->limit);
|
||||
count = le16_to_cpu(c->count);
|
||||
if (count_offset + (limit * sizeof(struct dx_entry)) >
|
||||
EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
|
||||
EXT4_ERROR_INODE(inode, "metadata_csum set but no space for "
|
||||
"tree checksum. Run e2fsck -D.");
|
||||
return;
|
||||
}
|
||||
t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
|
||||
|
||||
t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
|
||||
}
|
||||
|
||||
static inline int ext4_handle_dirty_dx_node(handle_t *handle,
|
||||
struct inode *inode,
|
||||
struct buffer_head *bh)
|
||||
{
|
||||
ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
|
||||
return ext4_handle_dirty_metadata(handle, inode, bh);
|
||||
}
|
||||
|
||||
/*
|
||||
* p is at least 6 bytes before the end of page
|
||||
*/
|
||||
@ -247,12 +362,20 @@ static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
|
||||
{
|
||||
unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
|
||||
EXT4_DIR_REC_LEN(2) - infosize;
|
||||
|
||||
if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
|
||||
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
|
||||
entry_space -= sizeof(struct dx_tail);
|
||||
return entry_space / sizeof(struct dx_entry);
|
||||
}
|
||||
|
||||
static inline unsigned dx_node_limit(struct inode *dir)
|
||||
{
|
||||
unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
|
||||
|
||||
if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
|
||||
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
|
||||
entry_space -= sizeof(struct dx_tail);
|
||||
return entry_space / sizeof(struct dx_entry);
|
||||
}
|
||||
|
||||
@ -398,6 +521,15 @@ dx_probe(const struct qstr *d_name, struct inode *dir,
|
||||
goto fail;
|
||||
}
|
||||
|
||||
if (!buffer_verified(bh) &&
|
||||
!ext4_dx_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data)) {
|
||||
ext4_warning(dir->i_sb, "Root failed checksum");
|
||||
brelse(bh);
|
||||
*err = ERR_BAD_DX_DIR;
|
||||
goto fail;
|
||||
}
|
||||
set_buffer_verified(bh);
|
||||
|
||||
entries = (struct dx_entry *) (((char *)&root->info) +
|
||||
root->info.info_length);
|
||||
|
||||
@ -458,6 +590,17 @@ dx_probe(const struct qstr *d_name, struct inode *dir,
|
||||
if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
|
||||
goto fail2;
|
||||
at = entries = ((struct dx_node *) bh->b_data)->entries;
|
||||
|
||||
if (!buffer_verified(bh) &&
|
||||
!ext4_dx_csum_verify(dir,
|
||||
(struct ext4_dir_entry *)bh->b_data)) {
|
||||
ext4_warning(dir->i_sb, "Node failed checksum");
|
||||
brelse(bh);
|
||||
*err = ERR_BAD_DX_DIR;
|
||||
goto fail;
|
||||
}
|
||||
set_buffer_verified(bh);
|
||||
|
||||
if (dx_get_limit(entries) != dx_node_limit (dir)) {
|
||||
ext4_warning(dir->i_sb,
|
||||
"dx entry: limit != node limit");
|
||||
@ -557,6 +700,15 @@ static int ext4_htree_next_block(struct inode *dir, __u32 hash,
|
||||
if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
|
||||
0, &err)))
|
||||
return err; /* Failure */
|
||||
|
||||
if (!buffer_verified(bh) &&
|
||||
!ext4_dx_csum_verify(dir,
|
||||
(struct ext4_dir_entry *)bh->b_data)) {
|
||||
ext4_warning(dir->i_sb, "Node failed checksum");
|
||||
return -EIO;
|
||||
}
|
||||
set_buffer_verified(bh);
|
||||
|
||||
p++;
|
||||
brelse(p->bh);
|
||||
p->bh = bh;
|
||||
@ -1232,7 +1384,7 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
|
||||
err = ext4_handle_dirty_metadata(handle, dir, bh2);
|
||||
if (err)
|
||||
goto journal_error;
|
||||
err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
|
||||
err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
|
||||
if (err)
|
||||
goto journal_error;
|
||||
brelse(bh2);
|
||||
@ -1419,7 +1571,7 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
|
||||
frame->bh = bh;
|
||||
bh = bh2;
|
||||
|
||||
ext4_handle_dirty_metadata(handle, dir, frame->bh);
|
||||
ext4_handle_dirty_dx_node(handle, dir, frame->bh);
|
||||
ext4_handle_dirty_metadata(handle, dir, bh);
|
||||
|
||||
de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
|
||||
@ -1594,7 +1746,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
|
||||
dxtrace(dx_show_index("node", frames[1].entries));
|
||||
dxtrace(dx_show_index("node",
|
||||
((struct dx_node *) bh2->b_data)->entries));
|
||||
err = ext4_handle_dirty_metadata(handle, dir, bh2);
|
||||
err = ext4_handle_dirty_dx_node(handle, dir, bh2);
|
||||
if (err)
|
||||
goto journal_error;
|
||||
brelse (bh2);
|
||||
@ -1620,7 +1772,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
|
||||
if (err)
|
||||
goto journal_error;
|
||||
}
|
||||
err = ext4_handle_dirty_metadata(handle, dir, frames[0].bh);
|
||||
err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
|
||||
if (err) {
|
||||
ext4_std_error(inode->i_sb, err);
|
||||
goto cleanup;
|
||||
|
Loading…
Reference in New Issue
Block a user