On Thu, Jun 03, 2010 at 04:19:48PM +0200, Jan Kara wrote: > > All of these problems go away if the quota file isn't visible from > > userspace, and it becomes a special file. In the short term I think > > we could make this change, but I think we would also have to (1) treat > > the quota file as immutable while quotas are enabled (so it cannot be > > opened for writing), (2) force an fsync of the quota file and a > > journal commit before enabling quotas, and (3) force a journal commit > > after disabling quotas. > Ted, that's what generic quota code actually does for you (unless > DQUOT_QUOTA_SYS_FILE flag is specified but that's not the case of ext?) > - see vfs_load_quota_inode. We do: > sync_filesystem(sb); > invalidate_bdev(sb->s_bdev); > .. > inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE; > .. > So unless someone tries to screw us really hard, we should be fine. That's good to hear. I think though we also need to call sync_filesystem(sb) in dquot_disable(). Currently it calls sb->s_op->sync_fs(), which forces out the superblock, and sync_blockdev() which forces out any dirty buffer heads, but it doesn't actually force a journal commit so that any pending journaled writes to the quota file are forced out. We need to either explicitly sync the quota files, or use sync_filesystem(sb) and sync everything. The former might be more polite; in fact it might be sufficient in vfs_load_quota_inode() as well? Or am I missing something? - Ted -- 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
