This is the "foot in the door" fs user for the flags in getattr in NFS.
This is Trond's patch updated to more fine-grained flags.
If the kernel knows that the application doesn't care about the atime
information, then we can avoid having to flush out writes, and we can avoid
revalidating the atime information.
OTOH, if the app sets STAT_REVALIDATE then we must force a revalidation of the
attribute metadata.
inode.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
Index: linux-2.6.29/fs/nfs/inode.c
===================================================================
--- linux-2.6.29.orig/fs/nfs/inode.c 2009-04-07 18:50:41.000000000 -0400
+++ linux-2.6.29/fs/nfs/inode.c 2009-04-07 18:53:56.000000000 -0400
@@ -475,9 +475,14 @@
int flags)
{
struct inode *inode = dentry->d_inode;
- int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
+ int force_reval = 0;
int err;
+ force_reval |= (flags & STAT_REVALIDATE) != 0;
+
+ if (flags & STAT_ATIME)
+ goto do_revalidate;
+
/*
* Flush out writes to the server in order to update c/mtime.
*
@@ -500,11 +505,12 @@
* - NFS never sets MS_NOATIME or MS_NODIRATIME so there is
* no point in checking those.
*/
- if ((mnt->mnt_flags & MNT_NOATIME) ||
- ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
- need_atime = 0;
+ if (!((mnt->mnt_flags & MNT_NOATIME) ||
+ ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))))
+ force_reval |= (NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME) != 0;
- if (need_atime)
+do_revalidate:
+ if (force_reval)
err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
else
err = nfs_revalidate_inode(NFS_SERVER(inode), inode);
