NFS: Optimise away unnecessary setattrs for open(O_TRUNC);
Currently, we will correctly optimise away a truncate that doesn't
change the file size. However, in the case of open(O_TRUNC), we
also want to optimise away the time changes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 88a8b69..360240c 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -828,7 +828,7 @@
p->o_arg.bitmask = server->attr_bitmask;
p->o_arg.dir_bitmask = server->cache_consistency_bitmask;
p->o_arg.claim = NFS4_OPEN_CLAIM_NULL;
- if (flags & O_CREAT) {
+ if (attrs != NULL && attrs->ia_valid != 0) {
u32 *s;
p->o_arg.u.attrs = &p->attrs;
@@ -885,7 +885,7 @@
{
int ret = 0;
- if (open_mode & O_EXCL)
+ if (open_mode & (O_EXCL|O_TRUNC))
goto out;
switch (mode & (FMODE_READ|FMODE_WRITE)) {
case FMODE_READ:
@@ -1033,7 +1033,7 @@
struct nfs4_state *state = opendata->state;
struct nfs_inode *nfsi = NFS_I(state->inode);
struct nfs_delegation *delegation;
- int open_mode = opendata->o_arg.open_flags & O_EXCL;
+ int open_mode = opendata->o_arg.open_flags & (O_EXCL|O_TRUNC);
fmode_t fmode = opendata->o_arg.fmode;
nfs4_stateid stateid;
int ret = -EAGAIN;
@@ -2431,6 +2431,10 @@
}
}
+ /* Deal with open(O_TRUNC) */
+ if (sattr->ia_valid & ATTR_OPEN)
+ sattr->ia_valid &= ~(ATTR_MTIME|ATTR_CTIME|ATTR_OPEN);
+
status = nfs4_do_setattr(inode, cred, fattr, sattr, state);
if (status == 0)
nfs_setattr_update_inode(inode, sattr);