From: Trond Myklebust <trondmy@gmail.com>
Date: Wed, 27 Nov 2019 17:05:51 -0500
Subject: [PATCH] nfsd: Ensure CLONE persists data and metadata changes to the
 target file
Git-commit: a25e3726b32c746c0098125d4c7463bb84df72bb
Patch-mainline: v5.5
References: git-fixes

The NFSv4.2 CLONE operation has implicit persistence requirements on the
target file, since there is no protocol requirement that the client issue
a separate operation to persist data.
For that reason, we should call vfs_fsync_range() on the destination file
after a successful call to vfs_clone_file_range().

Fixes: ffa0160a1039 ("nfsd: implement the NFSv4.2 CLONE operation")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 fs/nfsd/nfs4proc.c |    3 ++-
 fs/nfsd/vfs.c      |   15 ++++++++++++---
 fs/nfsd/vfs.h      |    2 +-
 3 files changed, 15 insertions(+), 5 deletions(-)

--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1056,7 +1056,8 @@ nfsd4_clone(struct svc_rqst *rqstp, stru
 		goto out;
 
 	status = nfsd4_clone_file_range(src, clone->cl_src_pos,
-			dst, clone->cl_dst_pos, clone->cl_count);
+			dst, clone->cl_dst_pos, clone->cl_count,
+			EX_ISSYNC(cstate->current_fh.fh_export));
 
 	fput(dst);
 	fput(src);
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -538,10 +538,19 @@ __be32 nfsd4_set_nfs4_label(struct svc_r
 #endif
 
 __be32 nfsd4_clone_file_range(struct file *src, u64 src_pos, struct file *dst,
-		u64 dst_pos, u64 count)
+		u64 dst_pos, u64 count, bool sync)
 {
-	return nfserrno(vfs_clone_file_range(src, src_pos, dst, dst_pos,
-					     count));
+	int ret = vfs_clone_file_range(src, src_pos, dst, dst_pos,
+				       count);
+	if (ret)
+		return nfserrno(ret);
+	if (sync) {
+		loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX;
+		int status = vfs_fsync_range(dst, dst_pos, dst_end, 0);
+		if (status < 0)
+			return nfserrno(status);
+	}
+	return 0;
 }
 
 ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
--- a/fs/nfsd/vfs.h
+++ b/fs/nfsd/vfs.h
@@ -57,7 +57,7 @@ __be32          nfsd4_set_nfs4_label(str
 __be32		nfsd4_vfs_fallocate(struct svc_rqst *, struct svc_fh *,
 				    struct file *, loff_t, loff_t, int);
 __be32		nfsd4_clone_file_range(struct file *, u64, struct file *,
-			u64, u64);
+				       u64, u64, bool);
 #endif /* CONFIG_NFSD_V4 */
 __be32		nfsd_create_locked(struct svc_rqst *, struct svc_fh *,
 				char *name, int len, struct iattr *attrs,