Hello Darrick J. Wong,
This is a semi-automatic email about new static checker warnings.
The patch b0336e8d2108: "ext4: calculate and verify checksums of
directory leaf blocks" from Apr 29, 2012, leads to the following
Smatch complaint:
fs/ext4/namei.c:1615 add_dirent_to_buf()
warn: variable dereferenced before check 'inode' (see line 1577)
fs/ext4/namei.c
1575 if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
^^^^^^^^^^^
New dereference.
1576 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1577 csum_size = sizeof(struct ext4_dir_entry_tail);
1578
1579 reclen = EXT4_DIR_REC_LEN(namelen);
1580 if (!de) {
1581 de = (struct ext4_dir_entry_2 *)bh->b_data;
1582 top = bh->b_data + (blocksize - csum_size) - reclen;
1583 while ((char *) de <= top) {
1584 if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
1585 return -EIO;
1586 if (ext4_match(namelen, name, de))
1587 return -EEXIST;
1588 nlen = EXT4_DIR_REC_LEN(de->name_len);
1589 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1590 if ((de->inode? rlen - nlen: rlen) >= reclen)
1591 break;
1592 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1593 offset += rlen;
1594 }
1595 if ((char *) de > top)
1596 return -ENOSPC;
1597 }
1598 BUFFER_TRACE(bh, "get_write_access");
1599 err = ext4_journal_get_write_access(handle, bh);
1600 if (err) {
1601 ext4_std_error(dir->i_sb, err);
1602 return err;
1603 }
1604
1605 /* By now the buffer is marked for journaling */
1606 nlen = EXT4_DIR_REC_LEN(de->name_len);
1607 rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1608 if (de->inode) {
1609 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1610 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1611 de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1612 de = de1;
1613 }
1614 de->file_type = EXT4_FT_UNKNOWN;
1615 if (inode) {
^^^^^
Old check.
1616 de->inode = cpu_to_le32(inode->i_ino);
1617 ext4_set_de_type(dir->i_sb, de, inode->i_mode);
regards,
dan carpenter
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