ext4: check free inode count before allocating an inode

Recently, I ecountered some corrupted filesystems in which some
groups' free inode counts were 65535, it seemed that free inode
count was overflow.  This patch teaches ext4 to check free inode
count before allocaing an inode.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Yongqiang Yang 2012-09-23 23:16:03 -04:00 committed by Theodore Ts'o
parent 838cd0cf9a
commit f2a09af645

View file

@ -697,6 +697,15 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, umode_t mode,
if (!gdp)
goto fail;
/*
* Check free inodes count before loading bitmap.
*/
if (ext4_free_inodes_count(sb, gdp) == 0) {
if (++group == ngroups)
group = 0;
continue;
}
brelse(inode_bitmap_bh);
inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
if (!inode_bitmap_bh)