smb3: Move the flush out of smb2_copychunk_range() into its callers

[ Upstream commit c3a72bb ]

Move the flush out of smb2_copychunk_range() into its callers.  This will
allow the pagecache to be invalidated between the flush and the operation
in smb3_collapse_range() and smb3_insert_range().

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Stable-dep-of: fa30a81 ("smb3: fix temporary data corruption in collapse range")
Signed-off-by: Sasha Levin <sashal@kernel.org>

fs/cifs/cifsfs.c

@@ -1203,6 +1203,8 @@ ssize_t cifs_file_copychunk_range(unsigned int xid,
 
 	cifs_dbg(FYI, "copychunk range\n");
 
+	filemap_write_and_wait(src_inode->i_mapping);
+
 	if (!src_file->private_data || !dst_file->private_data) {
 		rc = -EBADF;
 		cifs_dbg(VFS, "missing cifsFileInfo on copy range src file\n");

fs/cifs/smb2ops.c

@@ -1886,17 +1886,8 @@ smb2_copychunk_range(const unsigned int xid,
 	int chunks_copied = 0;
 	bool chunk_sizes_updated = false;
 	ssize_t bytes_written, total_bytes_written = 0;
-	struct inode *inode;
 
 	pcchunk = kmalloc(sizeof(struct copychunk_ioctl), GFP_KERNEL);
-
-	/*
-	 * We need to flush all unwritten data before we can send the
-	 * copychunk ioctl to the server.
-	 */
-	inode = d_inode(trgtfile->dentry);
-	filemap_write_and_wait(inode->i_mapping);
-
 	if (pcchunk == NULL)
 		return -ENOMEM;
 
@@ -3977,6 +3968,8 @@ static long smb3_collapse_range(struct file *file, struct cifs_tcon *tcon,
 		goto out;
 	}
 
+	filemap_write_and_wait(inode->i_mapping);
+
 	rc = smb2_copychunk_range(xid, cfile, cfile, off + len,
 				  i_size_read(inode) - off - len, off);
 	if (rc < 0)
@@ -4004,18 +3997,21 @@ static long smb3_insert_range(struct file *file, struct cifs_tcon *tcon,
 	int rc;
 	unsigned int xid;
 	struct cifsFileInfo *cfile = file->private_data;
+	struct inode *inode = file_inode(file);
 	__le64 eof;
 	__u64  count;
 
 	xid = get_xid();
 
-	if (off >= i_size_read(file->f_inode)) {
+	if (off >= i_size_read(inode)) {
 		rc = -EINVAL;
 		goto out;
 	}
 
-	count = i_size_read(file->f_inode) - off;
-	eof = cpu_to_le64(i_size_read(file->f_inode) + len);
+	count = i_size_read(inode) - off;
+	eof = cpu_to_le64(i_size_read(inode) + len);
+
+	filemap_write_and_wait(inode->i_mapping);
 
 	rc = SMB2_set_eof(xid, tcon, cfile->fid.persistent_fid,
 			  cfile->fid.volatile_fid, cfile->pid, &eof);