>> I tried that approach by adding a "int get_inode_usage(struct inode >> *inode, qsize_t *usage)" callback to dquot_operations. Unfortunately, >> ext4 code that calculates the number of internal inodes >> (ext4_xattr_inode_count()) is subject to failures so the callback has >> to be able to report errors. And, that itself is problematic because >> we can't afford to have errors in dquot_free_inode(). If you have >> thoughts about how to address this please let me know. > > Well, you can just make dquot_free_inode() return error. Now most callers > won't be able to do much with an error from dquot_free_inode() but that's > the case also for other things during inode deletion - just handle it as > other fatal failures during inode freeing. > I just checked dquot_free_inode() to see whether it calls anything that could fail. It calls mark_all_dquot_dirty() and ignores the return code from it. I would like to follow the same for the get_inode_usage() as the only use case for get_inode_usage() (ext4) should not fail at inode free time. Basically, I want to avoid changing return type from void to int because it would create a new responsibility for the filesystem implementations who do not know how to deal with it.