lkml.org 
[lkml]   [2004]   [Feb]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: 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/

\
 
 \ /
  Last update: 2005-03-22 14:01    [W:0.206 / U:0.596 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site