Messages in this thread | | | Date | Mon, 23 Feb 2004 11:59:54 +0100 | From | Pavel Machek <> | Subject | Re: explicit dcache <-> user-space cache coherency, sys_mark_dir_clean(), O_CLEAN |
| |
Hi!
> generation counters are problematic if they are not persistent. But > there's a pretty natural persistent 'generation counter' which could be > used for Samba's purpose: the mtime of the directory. The problem right > now is that it doesnt have enough resolution to be a true unique > generation counter. But having high-resolution mtime is a goal anyway. > > XFS is one filesystem that has high-resolution mtime: > > typedef struct xfs_timestamp { > __int32_t t_sec; /* timestamp seconds */ > __int32_t t_nsec; /* timestamp nanoseconds */ > } xfs_timestamp_t; > > monotonity is important: two successive directory operations to not be > possible within the same nanosecond. This is not possible with current > hardware - but how about future hardware? Can we make an assumption like > this?
Does not ndelay(1) if samba notices mtime is too young in the samba code fix that? -- 64 bytes from 195.113.31.123: icmp_seq=28 ttl=51 time=448769.1 ms
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |