Re: [PATCH] add some notes on file_update_time

[Christoph Hellwig <hch@lst.de>]

On Fri, Nov 11, 2005 at 12:45:27AM +0100, Christoph Hellwig wrote:
> > Nice explanation except for the last sentence.  Surely you do not expect 
> > filesystem drivers to call notify_change()?  I thought you told me that I 
> > should be setting the c/mtime directly, rather than using a function, so 
> > now you are going back on that?  Or am I simply misunderstanding the 
> > sentence completely?  I apologize if that is the case...
> 
> this was meant for non-fs callers.  but to be there's no reason
> why non-fs callers should look at this function in the first time.
> 
> The updated patch below just drop the sentence.  we might want to write
> up rules on c/mtime updates somewhere, but that's really not related to
> file_update_time.

And here's another update, as Nathan Scott found a small typo:

Index: linux-2.6/fs/inode.c
===================================================================
--- linux-2.6.orig/fs/inode.c	2005-11-10 16:02:18.000000000 +0100
+++ linux-2.6/fs/inode.c	2005-11-10 16:05:55.000000000 +0100
@@ -1208,7 +1208,11 @@
  *	@file: file accessed
  *
  *	Update the mtime and ctime members of an inode and mark the inode
- *	for writeback.
+ *	for writeback.  Note that this function is meant exclusively for
+ *	usage in the file write path of filesystems, and filesystems may
+ *	choose to explicitly ignore update via this function with the
+ *	S_NOCTIME inode flag, e.g. for network filesystem where these
+ *	timestamps are handled by the server.
  */
 
 void file_update_time(struct file *file)