On 2017/1/5 7:35, Theodore Ts'o wrote:
>
> So how exactly how did we get into this state? When we read the inode
> into memory, if i_nlink is zero, we declare the file system as
> corrupted immediately.
>
> So I assume this is happening the on-disk i_links_count (which is read
> into inode->i_nlink) was too low. So I think the way we should be
> handling this is in unlink and rename, before we let i_nlink drop to
> zero, we need to check to see if there are other dcache entries
> pointing at the inode. If so, we need to call ext4_error(), and in
> the errors=continue case, return EFSCORRUPTED (aka EUCLEAN).
>
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -3662,6 +3662,11 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
}
if (new.inode) {
+ if (new.inode->i_nlink == 0) {
+ ext4_warning_inode(new.inode, "Removing file '%.*s' with no links",
+ new.dentry->d_name.len, new.dentry->d_name.name);
+ set_nlink(new.inode, 1);
+ }
ext4_dec_count(handle, new.inode);
new.inode->i_ctime = ext4_current_time(new.inode);
}
Because the filesystem have many errors, and the reason of i_nlink becomes zero is unknown,
the on-disk i_links_count was too low may be one reason. I think we can add i_nlink check in
ext4_rename just like ext4_unlink did, it can avoid inversion under any case.
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
