[PATCH] Make kNFSd pre/post_[acm]time use struct timespec

From Trond:

  When the nanosecond resolution on [acm]time was introduced to 2.5.x,
the knfsd GETATTR responses were converted to make use of the
nanosecond field, but the pre/post WCC attributes were not. This will
lead to a lot of unnecessary cache invalidations on the clients.

The following trivial patch should fix up knfsd so that it stores and
encodes the full 'struct timespec' in both pre and post attribute
fields.

fs/nfsd/nfs3xdr.c

@@ -202,7 +202,6 @@ encode_fattr3(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
 static inline u32 *
 encode_saved_post_attr(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
 {
-	struct timespec  time;
 	struct inode	*inode = fhp->fh_dentry->d_inode;
 
 	/* Attributes to follow */
@@ -228,13 +227,9 @@ encode_saved_post_attr(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
 	else
 		p = xdr_encode_hyper(p, (u64) inode->i_sb->s_dev);
 	p = xdr_encode_hyper(p, (u64) inode->i_ino);
-	time.tv_sec = fhp->fh_post_atime; 
-	time.tv_nsec = 0;
-	p = encode_time3(p, &time);
-	time.tv_sec = fhp->fh_post_mtime;
-	p = encode_time3(p, &time);
-	time.tv_sec = fhp->fh_post_ctime; 
-	p = encode_time3(p, &time);
+	p = encode_time3(p, &fhp->fh_post_atime);
+	p = encode_time3(p, &fhp->fh_post_mtime);
+	p = encode_time3(p, &fhp->fh_post_ctime);
 
 	return p;
 }
@@ -266,14 +261,10 @@ encode_wcc_data(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
 
 	if (dentry && dentry->d_inode && fhp->fh_post_saved) {
 		if (fhp->fh_pre_saved) {
-			struct timespec time;
 			*p++ = xdr_one;
 			p = xdr_encode_hyper(p, (u64) fhp->fh_pre_size);
-			time.tv_nsec = 0;
-			time.tv_sec =  fhp->fh_pre_mtime;
-			p = encode_time3(p, &time);
-			time.tv_sec = fhp->fh_pre_ctime;
-			p = encode_time3(p, &time);
+			p = encode_time3(p, &fhp->fh_pre_mtime);
+			p = encode_time3(p, &fhp->fh_pre_ctime);
 		} else {
 			*p++ = xdr_zero;
 		}

include/linux/nfsd/nfsfh.h

@@ -165,8 +165,8 @@ typedef struct svc_fh {
 
 	/* Pre-op attributes saved during fh_lock */
 	__u64			fh_pre_size;	/* size before operation */
-	time_t			fh_pre_mtime;	/* mtime before oper */
-	time_t			fh_pre_ctime;	/* ctime before oper */
+	struct timespec		fh_pre_mtime;	/* mtime before oper */
+	struct timespec		fh_pre_ctime;	/* ctime before oper */
 
 	/* Post-op attributes saved in fh_unlock */
 	umode_t			fh_post_mode;	/* i_mode */
@@ -177,9 +177,9 @@ typedef struct svc_fh {
 	unsigned long		fh_post_blocks; /* i_blocks */
 	unsigned long		fh_post_blksize;/* i_blksize */
 	__u32			fh_post_rdev[2];/* i_rdev */
-	time_t			fh_post_atime;	/* i_atime */
-	time_t			fh_post_mtime;	/* i_mtime */
-	time_t			fh_post_ctime;	/* i_ctime */
+	struct timespec		fh_post_atime;	/* i_atime */
+	struct timespec		fh_post_mtime;	/* i_mtime */
+	struct timespec		fh_post_ctime;	/* i_ctime */
 #endif /* CONFIG_NFSD_V3 */
 
 } svc_fh;
@@ -263,8 +263,8 @@ fill_pre_wcc(struct svc_fh *fhp)
 
 	inode = fhp->fh_dentry->d_inode;
 	if (!fhp->fh_pre_saved) {
-		fhp->fh_pre_mtime = inode->i_mtime.tv_sec;
-		fhp->fh_pre_ctime = inode->i_ctime.tv_sec;
+		fhp->fh_pre_mtime = inode->i_mtime;
+		fhp->fh_pre_ctime = inode->i_ctime;
 			fhp->fh_pre_size  = inode->i_size;
 			fhp->fh_pre_saved = 1;
 	}
@@ -296,9 +296,9 @@ fill_post_wcc(struct svc_fh *fhp)
 	}
 	fhp->fh_post_rdev[0]    = htonl((u32)major(inode->i_rdev));
 	fhp->fh_post_rdev[1]    = htonl((u32)minor(inode->i_rdev));
-	fhp->fh_post_atime      = inode->i_atime.tv_sec;
-	fhp->fh_post_mtime      = inode->i_mtime.tv_sec;
-	fhp->fh_post_ctime      = inode->i_ctime.tv_sec;
+	fhp->fh_post_atime      = inode->i_atime;
+	fhp->fh_post_mtime      = inode->i_mtime;
+	fhp->fh_post_ctime      = inode->i_ctime;
 	fhp->fh_post_saved      = 1;
 }
 #else

include/linux/nfsd/xdr4.h

@@ -331,9 +331,9 @@ set_change_info(struct nfsd4_change_info *cinfo, struct svc_fh *fhp)
 	BUG_ON(!fhp->fh_pre_saved || !fhp->fh_post_saved);
 	cinfo->atomic = 1;
 	cinfo->before_size = fhp->fh_pre_size;
-	cinfo->before_ctime = fhp->fh_pre_ctime;
+	cinfo->before_ctime = fhp->fh_pre_ctime.tv_sec;
 	cinfo->after_size = fhp->fh_post_size;
-	cinfo->after_ctime = fhp->fh_post_ctime;
+	cinfo->after_ctime = fhp->fh_post_ctime.tv_sec;
 }
 
 int nfs4svc_encode_voidres(struct svc_rqst *, u32 *, void *);