ext4: Avoid rec_len overflow with 64KB block size
With 64KB blocksize, a directory entry can have size 64KB which does not fit into 16 bits we have for entry lenght. So we store 0xffff instead and convert value when read from / written to disk. The patch also converts some places to use ext4_next_entry() when we are changing them anyway. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mingming Cao <cmm@us.ibm.com>
This commit is contained in:
Родитель
afc7cbca5b
Коммит
a72d7f834e
|
@ -67,7 +67,7 @@ int ext4_check_dir_entry (const char * function, struct inode * dir,
|
|||
unsigned long offset)
|
||||
{
|
||||
const char * error_msg = NULL;
|
||||
const int rlen = le16_to_cpu(de->rec_len);
|
||||
const int rlen = ext4_rec_len_from_disk(de->rec_len);
|
||||
|
||||
if (rlen < EXT4_DIR_REC_LEN(1))
|
||||
error_msg = "rec_len is smaller than minimal";
|
||||
|
@ -172,10 +172,10 @@ revalidate:
|
|||
* least that it is non-zero. A
|
||||
* failure will be detected in the
|
||||
* dirent test below. */
|
||||
if (le16_to_cpu(de->rec_len) <
|
||||
EXT4_DIR_REC_LEN(1))
|
||||
if (ext4_rec_len_from_disk(de->rec_len)
|
||||
< EXT4_DIR_REC_LEN(1))
|
||||
break;
|
||||
i += le16_to_cpu(de->rec_len);
|
||||
i += ext4_rec_len_from_disk(de->rec_len);
|
||||
}
|
||||
offset = i;
|
||||
filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
|
||||
|
@ -197,7 +197,7 @@ revalidate:
|
|||
ret = stored;
|
||||
goto out;
|
||||
}
|
||||
offset += le16_to_cpu(de->rec_len);
|
||||
offset += ext4_rec_len_from_disk(de->rec_len);
|
||||
if (le32_to_cpu(de->inode)) {
|
||||
/* We might block in the next section
|
||||
* if the data destination is
|
||||
|
@ -219,7 +219,7 @@ revalidate:
|
|||
goto revalidate;
|
||||
stored ++;
|
||||
}
|
||||
filp->f_pos += le16_to_cpu(de->rec_len);
|
||||
filp->f_pos += ext4_rec_len_from_disk(de->rec_len);
|
||||
}
|
||||
offset = 0;
|
||||
brelse (bh);
|
||||
|
|
|
@ -280,7 +280,7 @@ static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_ent
|
|||
space += EXT4_DIR_REC_LEN(de->name_len);
|
||||
names++;
|
||||
}
|
||||
de = (struct ext4_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
|
||||
de = ext4_next_entry(de);
|
||||
}
|
||||
printk("(%i)\n", names);
|
||||
return (struct stats) { names, space, 1 };
|
||||
|
@ -551,7 +551,8 @@ static int ext4_htree_next_block(struct inode *dir, __u32 hash,
|
|||
*/
|
||||
static inline struct ext4_dir_entry_2 *ext4_next_entry(struct ext4_dir_entry_2 *p)
|
||||
{
|
||||
return (struct ext4_dir_entry_2 *)((char*)p + le16_to_cpu(p->rec_len));
|
||||
return (struct ext4_dir_entry_2 *)((char *)p +
|
||||
ext4_rec_len_from_disk(p->rec_len));
|
||||
}
|
||||
|
||||
/*
|
||||
|
@ -720,7 +721,7 @@ static int dx_make_map (struct ext4_dir_entry_2 *de, int size,
|
|||
cond_resched();
|
||||
}
|
||||
/* XXX: do we need to check rec_len == 0 case? -Chris */
|
||||
de = (struct ext4_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
|
||||
de = ext4_next_entry(de);
|
||||
}
|
||||
return count;
|
||||
}
|
||||
|
@ -820,7 +821,7 @@ static inline int search_dirblock(struct buffer_head * bh,
|
|||
return 1;
|
||||
}
|
||||
/* prevent looping on a bad block */
|
||||
de_len = le16_to_cpu(de->rec_len);
|
||||
de_len = ext4_rec_len_from_disk(de->rec_len);
|
||||
if (de_len <= 0)
|
||||
return -1;
|
||||
offset += de_len;
|
||||
|
@ -1128,7 +1129,7 @@ dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count)
|
|||
rec_len = EXT4_DIR_REC_LEN(de->name_len);
|
||||
memcpy (to, de, rec_len);
|
||||
((struct ext4_dir_entry_2 *) to)->rec_len =
|
||||
cpu_to_le16(rec_len);
|
||||
ext4_rec_len_to_disk(rec_len);
|
||||
de->inode = 0;
|
||||
map++;
|
||||
to += rec_len;
|
||||
|
@ -1147,13 +1148,12 @@ static struct ext4_dir_entry_2* dx_pack_dirents(char *base, int size)
|
|||
|
||||
prev = to = de;
|
||||
while ((char*)de < base + size) {
|
||||
next = (struct ext4_dir_entry_2 *) ((char *) de +
|
||||
le16_to_cpu(de->rec_len));
|
||||
next = ext4_next_entry(de);
|
||||
if (de->inode && de->name_len) {
|
||||
rec_len = EXT4_DIR_REC_LEN(de->name_len);
|
||||
if (de > to)
|
||||
memmove(to, de, rec_len);
|
||||
to->rec_len = cpu_to_le16(rec_len);
|
||||
to->rec_len = ext4_rec_len_to_disk(rec_len);
|
||||
prev = to;
|
||||
to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
|
||||
}
|
||||
|
@ -1227,8 +1227,8 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
|
|||
/* Fancy dance to stay within two buffers */
|
||||
de2 = dx_move_dirents(data1, data2, map + split, count - split);
|
||||
de = dx_pack_dirents(data1,blocksize);
|
||||
de->rec_len = cpu_to_le16(data1 + blocksize - (char *) de);
|
||||
de2->rec_len = cpu_to_le16(data2 + blocksize - (char *) de2);
|
||||
de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de);
|
||||
de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2);
|
||||
dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
|
||||
dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
|
||||
|
||||
|
@ -1297,7 +1297,7 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
|
|||
return -EEXIST;
|
||||
}
|
||||
nlen = EXT4_DIR_REC_LEN(de->name_len);
|
||||
rlen = le16_to_cpu(de->rec_len);
|
||||
rlen = ext4_rec_len_from_disk(de->rec_len);
|
||||
if ((de->inode? rlen - nlen: rlen) >= reclen)
|
||||
break;
|
||||
de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
|
||||
|
@ -1316,11 +1316,11 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
|
|||
|
||||
/* By now the buffer is marked for journaling */
|
||||
nlen = EXT4_DIR_REC_LEN(de->name_len);
|
||||
rlen = le16_to_cpu(de->rec_len);
|
||||
rlen = ext4_rec_len_from_disk(de->rec_len);
|
||||
if (de->inode) {
|
||||
struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
|
||||
de1->rec_len = cpu_to_le16(rlen - nlen);
|
||||
de->rec_len = cpu_to_le16(nlen);
|
||||
de1->rec_len = ext4_rec_len_to_disk(rlen - nlen);
|
||||
de->rec_len = ext4_rec_len_to_disk(nlen);
|
||||
de = de1;
|
||||
}
|
||||
de->file_type = EXT4_FT_UNKNOWN;
|
||||
|
@ -1397,17 +1397,18 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
|
|||
|
||||
/* The 0th block becomes the root, move the dirents out */
|
||||
fde = &root->dotdot;
|
||||
de = (struct ext4_dir_entry_2 *)((char *)fde + le16_to_cpu(fde->rec_len));
|
||||
de = (struct ext4_dir_entry_2 *)((char *)fde +
|
||||
ext4_rec_len_from_disk(fde->rec_len));
|
||||
len = ((char *) root) + blocksize - (char *) de;
|
||||
memcpy (data1, de, len);
|
||||
de = (struct ext4_dir_entry_2 *) data1;
|
||||
top = data1 + len;
|
||||
while ((char *)(de2=(void*)de+le16_to_cpu(de->rec_len)) < top)
|
||||
while ((char *)(de2 = ext4_next_entry(de)) < top)
|
||||
de = de2;
|
||||
de->rec_len = cpu_to_le16(data1 + blocksize - (char *) de);
|
||||
de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de);
|
||||
/* Initialize the root; the dot dirents already exist */
|
||||
de = (struct ext4_dir_entry_2 *) (&root->dotdot);
|
||||
de->rec_len = cpu_to_le16(blocksize - EXT4_DIR_REC_LEN(2));
|
||||
de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2));
|
||||
memset (&root->info, 0, sizeof(root->info));
|
||||
root->info.info_length = sizeof(root->info);
|
||||
root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
|
||||
|
@ -1487,7 +1488,7 @@ static int ext4_add_entry (handle_t *handle, struct dentry *dentry,
|
|||
return retval;
|
||||
de = (struct ext4_dir_entry_2 *) bh->b_data;
|
||||
de->inode = 0;
|
||||
de->rec_len = cpu_to_le16(blocksize);
|
||||
de->rec_len = ext4_rec_len_to_disk(blocksize);
|
||||
return add_dirent_to_buf(handle, dentry, inode, de, bh);
|
||||
}
|
||||
|
||||
|
@ -1550,7 +1551,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
|
|||
goto cleanup;
|
||||
node2 = (struct dx_node *)(bh2->b_data);
|
||||
entries2 = node2->entries;
|
||||
node2->fake.rec_len = cpu_to_le16(sb->s_blocksize);
|
||||
node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize);
|
||||
node2->fake.inode = 0;
|
||||
BUFFER_TRACE(frame->bh, "get_write_access");
|
||||
err = ext4_journal_get_write_access(handle, frame->bh);
|
||||
|
@ -1648,9 +1649,9 @@ static int ext4_delete_entry (handle_t *handle,
|
|||
BUFFER_TRACE(bh, "get_write_access");
|
||||
ext4_journal_get_write_access(handle, bh);
|
||||
if (pde)
|
||||
pde->rec_len =
|
||||
cpu_to_le16(le16_to_cpu(pde->rec_len) +
|
||||
le16_to_cpu(de->rec_len));
|
||||
pde->rec_len = ext4_rec_len_to_disk(
|
||||
ext4_rec_len_from_disk(pde->rec_len) +
|
||||
ext4_rec_len_from_disk(de->rec_len));
|
||||
else
|
||||
de->inode = 0;
|
||||
dir->i_version++;
|
||||
|
@ -1658,10 +1659,9 @@ static int ext4_delete_entry (handle_t *handle,
|
|||
ext4_journal_dirty_metadata(handle, bh);
|
||||
return 0;
|
||||
}
|
||||
i += le16_to_cpu(de->rec_len);
|
||||
i += ext4_rec_len_from_disk(de->rec_len);
|
||||
pde = de;
|
||||
de = (struct ext4_dir_entry_2 *)
|
||||
((char *) de + le16_to_cpu(de->rec_len));
|
||||
de = ext4_next_entry(de);
|
||||
}
|
||||
return -ENOENT;
|
||||
}
|
||||
|
@ -1824,13 +1824,13 @@ retry:
|
|||
de = (struct ext4_dir_entry_2 *) dir_block->b_data;
|
||||
de->inode = cpu_to_le32(inode->i_ino);
|
||||
de->name_len = 1;
|
||||
de->rec_len = cpu_to_le16(EXT4_DIR_REC_LEN(de->name_len));
|
||||
de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len));
|
||||
strcpy (de->name, ".");
|
||||
ext4_set_de_type(dir->i_sb, de, S_IFDIR);
|
||||
de = (struct ext4_dir_entry_2 *)
|
||||
((char *) de + le16_to_cpu(de->rec_len));
|
||||
de = ext4_next_entry(de);
|
||||
de->inode = cpu_to_le32(dir->i_ino);
|
||||
de->rec_len = cpu_to_le16(inode->i_sb->s_blocksize-EXT4_DIR_REC_LEN(1));
|
||||
de->rec_len = ext4_rec_len_to_disk(inode->i_sb->s_blocksize -
|
||||
EXT4_DIR_REC_LEN(1));
|
||||
de->name_len = 2;
|
||||
strcpy (de->name, "..");
|
||||
ext4_set_de_type(dir->i_sb, de, S_IFDIR);
|
||||
|
@ -1882,8 +1882,7 @@ static int empty_dir (struct inode * inode)
|
|||
return 1;
|
||||
}
|
||||
de = (struct ext4_dir_entry_2 *) bh->b_data;
|
||||
de1 = (struct ext4_dir_entry_2 *)
|
||||
((char *) de + le16_to_cpu(de->rec_len));
|
||||
de1 = ext4_next_entry(de);
|
||||
if (le32_to_cpu(de->inode) != inode->i_ino ||
|
||||
!le32_to_cpu(de1->inode) ||
|
||||
strcmp (".", de->name) ||
|
||||
|
@ -1894,9 +1893,9 @@ static int empty_dir (struct inode * inode)
|
|||
brelse (bh);
|
||||
return 1;
|
||||
}
|
||||
offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len);
|
||||
de = (struct ext4_dir_entry_2 *)
|
||||
((char *) de1 + le16_to_cpu(de1->rec_len));
|
||||
offset = ext4_rec_len_from_disk(de->rec_len) +
|
||||
ext4_rec_len_from_disk(de1->rec_len);
|
||||
de = ext4_next_entry(de1);
|
||||
while (offset < inode->i_size ) {
|
||||
if (!bh ||
|
||||
(void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
|
||||
|
@ -1925,9 +1924,8 @@ static int empty_dir (struct inode * inode)
|
|||
brelse (bh);
|
||||
return 0;
|
||||
}
|
||||
offset += le16_to_cpu(de->rec_len);
|
||||
de = (struct ext4_dir_entry_2 *)
|
||||
((char *) de + le16_to_cpu(de->rec_len));
|
||||
offset += ext4_rec_len_from_disk(de->rec_len);
|
||||
de = ext4_next_entry(de);
|
||||
}
|
||||
brelse (bh);
|
||||
return 1;
|
||||
|
@ -2282,8 +2280,7 @@ retry:
|
|||
}
|
||||
|
||||
#define PARENT_INO(buffer) \
|
||||
((struct ext4_dir_entry_2 *) ((char *) buffer + \
|
||||
le16_to_cpu(((struct ext4_dir_entry_2 *) buffer)->rec_len)))->inode
|
||||
(ext4_next_entry((struct ext4_dir_entry_2 *)(buffer))->inode)
|
||||
|
||||
/*
|
||||
* Anybody can rename anything with this: the permission checks are left to the
|
||||
|
|
|
@ -767,6 +767,26 @@ struct ext4_dir_entry_2 {
|
|||
#define EXT4_DIR_ROUND (EXT4_DIR_PAD - 1)
|
||||
#define EXT4_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT4_DIR_ROUND) & \
|
||||
~EXT4_DIR_ROUND)
|
||||
#define EXT4_MAX_REC_LEN ((1<<16)-1)
|
||||
|
||||
static inline unsigned ext4_rec_len_from_disk(__le16 dlen)
|
||||
{
|
||||
unsigned len = le16_to_cpu(dlen);
|
||||
|
||||
if (len == EXT4_MAX_REC_LEN)
|
||||
return 1 << 16;
|
||||
return len;
|
||||
}
|
||||
|
||||
static inline __le16 ext4_rec_len_to_disk(unsigned len)
|
||||
{
|
||||
if (len == (1 << 16))
|
||||
return cpu_to_le16(EXT4_MAX_REC_LEN);
|
||||
else if (len > (1 << 16))
|
||||
BUG();
|
||||
return cpu_to_le16(len);
|
||||
}
|
||||
|
||||
/*
|
||||
* Hash Tree Directory indexing
|
||||
* (c) Daniel Phillips, 2001
|
||||
|
|
Загрузка…
Ссылка в новой задаче