Re: [PATCH] update ctime and mtime for mmaped write

From: Peter Staubach
Date: Wed Feb 21 2007 - 13:51:35 EST


Trond Myklebust wrote:
On Wed, 2007-02-21 at 19:28 +0100, Miklos Szeredi wrote:
This flag is checked in msync() and __fput(), and if set, the file
times are updated and the flag is cleared
Why not also check inside vfs_getattr?
This is the minimum, that the standard asks for.

Note, your porposal would touch the times in vfs_getattr(), which
means, that the modification times would depend on the time of the
last stat() call, which is not really right, though it would still be
conforming.

It is much saner, if the modification time is always the time of the
last write() or msync().

I disagree. The above doesn't allow a program like 'make' to discover
whether or not the file has changed by simply calling stat(). Instead,
you're forcing a call to msync()+stat().

Right, but that's what the specification specifies. The file times
for mmap'd files are not maintained as tightly as they are for files
which are being modified via write(2).

Rightly or wrongly.

ps
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