Re: [PATCH] replace inode_update_time with file_update_time

[Christoph Hellwig <hch@lst.de>]

On Mon, Nov 07, 2005 at 09:40:51PM +0000, Anton Altaparmakov wrote:
> On Sat, 29 Oct 2005, Christoph Hellwig wrote:
> > To allow various options to work per-mount instead of per-sb we need
> 
> What are those various options?  Please spell them out.  (I mean it!  I 
> really do not know what you have in mind and I cannot see anything that 
> would require a vfs mount wrt cmtime updates.)

The ones I work now are noatime and read-only.

> I believe your patch is wrong/unnecessary because the only option that is 
> per superblock (or in your new world per vfsmount) is the IS_RDONLY(inode) 
> check and if a mount is read-only the VFS should never have allowed 
> inode/file_update_time() to be called.  The codepath should have been 
> aborted _much_ earlier than that so it does not make any sense to test for 
> read-only here thus it is not necessary to do a per mountpoint check.  
> Instead we should remove the readonly check altogether and if there are 
> any places where an update of cmtime is attempted on a read-only mount we 
> should fix those instead...
> 
> A more detailed justification for your patch is IMO required before it be 
> applied to mainline, especially as it breaks existing file systems like 
> ntfs (as discussed offlist).

Besides the above usage it's a nice cleanup and already found bugs like
the API abuse in ntfs ->truncate.