cifs: change smb2_query_eas to use the compound query-info helper

Reducing the number of network roundtrips improves the performance
of query xattrs

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/smb2ops.c

@@ -831,72 +831,48 @@ smb2_query_eas(const unsigned int xid, struct cifs_tcon *tcon,
 {
 	int rc;
 	__le16 *utf16_path;
-	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
-	struct cifs_open_parms oparms;
-	struct cifs_fid fid;
-	struct smb2_file_full_ea_info *smb2_data;
-	int ea_buf_size = SMB2_MIN_EA_BUF;
+	struct kvec rsp_iov = {NULL, 0};
+	int buftype = CIFS_NO_BUFFER;
+	struct smb2_query_info_rsp *rsp;
+	struct smb2_file_full_ea_info *info = NULL;
 
 	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
 	if (!utf16_path)
 		return -ENOMEM;
 
-	oparms.tcon = tcon;
-	oparms.desired_access = FILE_READ_EA;
-	oparms.disposition = FILE_OPEN;
-	if (backup_cred(cifs_sb))
-		oparms.create_options = CREATE_OPEN_BACKUP_INTENT;
-	else
-		oparms.create_options = 0;
-	oparms.fid = &fid;
-	oparms.reconnect = false;
-
-	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL, NULL);
-	kfree(utf16_path);
+	rc = smb2_query_info_compound(xid, tcon, utf16_path,
+				      FILE_READ_EA,
+				      FILE_FULL_EA_INFORMATION,
+				      SMB2_O_INFO_FILE,
+				      SMB2_MAX_EA_BUF,
+				      &rsp_iov, &buftype, cifs_sb);
 	if (rc) {
-		cifs_dbg(FYI, "open failed rc=%d\n", rc);
-		return rc;
+		/*
+		 * If ea_name is NULL (listxattr) and there are no EAs,
+		 * return 0 as it's not an error. Otherwise, the specified
+		 * ea_name was not found.
+		 */
+		if (!ea_name && rc == -ENODATA)
+			rc = 0;
+		goto qeas_exit;
 	}
 
-	while (1) {
-		smb2_data = kzalloc(ea_buf_size, GFP_KERNEL);
-		if (smb2_data == NULL) {
-			SMB2_close(xid, tcon, fid.persistent_fid,
-				   fid.volatile_fid);
-			return -ENOMEM;
-		}
+	rsp = (struct smb2_query_info_rsp *)rsp_iov.iov_base;
+	rc = smb2_validate_iov(le16_to_cpu(rsp->OutputBufferOffset),
+			       le32_to_cpu(rsp->OutputBufferLength),
+			       &rsp_iov,
+			       sizeof(struct smb2_file_full_ea_info));
+	if (rc)
+		goto qeas_exit;
 
-		rc = SMB2_query_eas(xid, tcon, fid.persistent_fid,
-				    fid.volatile_fid,
-				    ea_buf_size, smb2_data);
+	info = (struct smb2_file_full_ea_info *)(
+			le16_to_cpu(rsp->OutputBufferOffset) + (char *)rsp);
+	rc = move_smb2_ea_to_cifs(ea_data, buf_size, info,
+			le32_to_cpu(rsp->OutputBufferLength), ea_name);
 
-		if (rc != -E2BIG)
-			break;
-
-		kfree(smb2_data);
-		ea_buf_size <<= 1;
-
-		if (ea_buf_size > SMB2_MAX_EA_BUF) {
-			cifs_dbg(VFS, "EA size is too large\n");
-			SMB2_close(xid, tcon, fid.persistent_fid,
-				   fid.volatile_fid);
-			return -ENOMEM;
-		}
-	}
-
-	SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
-
-	/*
-	 * If ea_name is NULL (listxattr) and there are no EAs, return 0 as it's
-	 * not an error. Otherwise, the specified ea_name was not found.
-	 */
-	if (!rc)
-		rc = move_smb2_ea_to_cifs(ea_data, buf_size, smb2_data,
-					  SMB2_MAX_EA_BUF, ea_name);
-	else if (!ea_name && rc == -ENODATA)
-		rc = 0;
-
-	kfree(smb2_data);
+ qeas_exit:
+	kfree(utf16_path);
+	free_rsp_buf(buftype, rsp_iov.iov_base);
 	return rc;
 }
 
@@ -1841,11 +1817,12 @@ smb2_set_next_command(struct TCP_Server_Info *server, struct smb_rqst *rqst,
  * Passes the query info response back to the caller on success.
  * Caller need to free this with free_rsp_buf().
  */
-static int
+int
 smb2_query_info_compound(const unsigned int xid, struct cifs_tcon *tcon,
 			 __le16 *utf16_path, u32 desired_access,
 			 u32 class, u32 type, u32 output_len,
-			 struct kvec *rsp, int *buftype)
+			 struct kvec *rsp, int *buftype,
+			 struct cifs_sb_info *cifs_sb)
 {
 	struct cifs_ses *ses = tcon->ses;
 	struct TCP_Server_Info *server = ses->server;
@@ -1875,7 +1852,10 @@ smb2_query_info_compound(const unsigned int xid, struct cifs_tcon *tcon,
 	oparms.tcon = tcon;
 	oparms.desired_access = desired_access;
 	oparms.disposition = FILE_OPEN;
-	oparms.create_options = 0;
+	if (cifs_sb && backup_cred(cifs_sb))
+		oparms.create_options = CREATE_OPEN_BACKUP_INTENT;
+	else
+		oparms.create_options = 0;
 	oparms.fid = &fid;
 	oparms.reconnect = false;
 
@@ -1908,9 +1888,10 @@ smb2_query_info_compound(const unsigned int xid, struct cifs_tcon *tcon,
 
 	rc = compound_send_recv(xid, ses, flags, 3, rqst,
 				resp_buftype, rsp_iov);
-	if (rc)
+	if (rc) {
+		free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
 		goto qic_exit;
-
+	}
 	*rsp = rsp_iov[1];
 	*buftype = resp_buftype[1];
 
@@ -1940,7 +1921,7 @@ smb2_queryfs(const unsigned int xid, struct cifs_tcon *tcon,
 				      FS_FULL_SIZE_INFORMATION,
 				      SMB2_O_INFO_FILESYSTEM,
 				      sizeof(struct smb2_fs_full_size_info),
-				      &rsp_iov, &buftype);
+				      &rsp_iov, &buftype, NULL);
 	if (rc)
 		goto qfs_exit;