Eric Van Hensbergen wrote on Sat, Feb 18, 2023 at 12:33:16AM +0000: > These flags just add unnecessary extra operations. > When 9p is run without cache, it inherently implements > these options so we don't need them in the superblock > (which ends up sending extraneous fsyncs, etc.). User > can still request these options on mount, but we don't > need to set them as default. Hm, I don't see where they'd add any operations -- if you have time would you mind pointing me at some? As far as I can see, it's just about 'sync' or 'dirsync' in /proc/mounts and the ST_SYNCHRONOUS statvfs flag; that looks harmless to me and it looks more correct to keep to me. (Sorry, didn't take the time to actually try taking a trace; I've checked the flag itself and the IS_SYNC/IS_DIRSYNC -> inode_needs_sync wrappers and that only seems used by specific filesystems who'd care about users setting the mount options, not the other way aorund.) -- Dominique
