svn commit: r188831 - head/sys/nfsclient

[Robert Watson]

On Thu, 19 Feb 2009, John Baldwin wrote:

> Author: jhb
> Date: Thu Feb 19 22:10:39 2009
> New Revision: 188831
> URL: http://svn.freebsd.org/changeset/base/188831
>
> Log:
>  Don't clear the attribute cache of a file when it is closed.  A subsequent
>  open() of the same file will load fresh attributes, so they do not need to
>  be explicitly flushed in close() to guarantee close to open consistency.
>  However, other file desciptors may still reference this file and clearing
>  the attributes in close() forces those other file descriptors to fetch
>  fresh attributes the next time they need them.

(hand wave) Not an area of expertise for me, but I was under the loose 
impression that one of the reasons for this refresh was to pull in new 
timestamps, etc so that applications using file attributes to track 
modification time, size, etc definitely saw the right thing reflecting the 
server interpretation of all the pending writes having been flushed back on 
close(). (more hand waving)

Robert N M Watson
Computer Laboratory
University of Cambridge

>
>  Reviewed by:	mohans
>  MFC after:	1 week
>
> Modified:
>  head/sys/nfsclient/nfs_vnops.c
>
> Modified: head/sys/nfsclient/nfs_vnops.c
> ==============================================================================
> --- head/sys/nfsclient/nfs_vnops.c	Thu Feb 19 21:29:30 2009	(r188830)
> +++ head/sys/nfsclient/nfs_vnops.c	Thu Feb 19 22:10:39 2009	(r188831)
> @@ -594,13 +594,6 @@ nfs_close(struct vop_close_args *ap)
> 		    error = nfs_vinvalbuf(vp, V_SAVE, ap->a_td, 1);
> 		mtx_lock(&np->n_mtx);
> 	    }
> - 	    /*
> - 	     * Invalidate the attribute cache in all cases.
> - 	     * An open is going to fetch fresh attrs any way, other procs
> - 	     * on this node that have file open will be forced to do an
> - 	     * otw attr fetch, but this is safe.
> - 	     */
> -	    np->n_attrstamp = 0;
> 	    if (np->n_flag & NWRITEERR) {
> 		np->n_flag &= ~NWRITEERR;
> 		error = np->n_error;
>