fs: fix writeFile[Sync] for non-seekable files

Completely disables the use of positioned writes at
writeFile and writeFileSync, which allows it to work
with non-seekable files.
Fixes: #31926
Backport-PR-URL: #32172
PR-URL: #32006
Reviewed-By: Anna Henningsen <anna@addaleax.net>

Author: mildsunrise

lib/fs.js

@@ -1240,9 +1240,9 @@ function futimesSync(fd, atime, mtime) {
 handleErrorFromBinding(ctx);
 }
 
-functionwriteAll(fd,isUserFd,buffer,offset,length,position,callback){
+functionwriteAll(fd,isUserFd,buffer,offset,length,callback){
 // write(fd, buffer, offset, length, position, callback)
-fs.write(fd,buffer,offset,length,position,(writeErr,written)=>{
+fs.write(fd,buffer,offset,length,null,(writeErr,written)=>{
 if(writeErr){
 if(isUserFd){
 callback(writeErr);
@@ -1260,10 +1260,7 @@ function writeAll(fd, isUserFd, buffer, offset, length, position, callback) {
 }else{
 offset+=written;
 length-=written;
-if(position!==null){
-position+=written;
-}
-writeAll(fd,isUserFd,buffer,offset,length,position,callback);
+writeAll(fd,isUserFd,buffer,offset,length,callback);
 }
 });
 }
@@ -1289,9 +1286,8 @@ function writeFile(path, data, options, callback) {
 functionwriteFd(fd,isUserFd){
 constbuffer=isArrayBufferView(data) ?
 data : Buffer.from(''+data,options.encoding||'utf8');
-constposition=(/a/.test(flag)||isUserFd) ? null : 0;
 
-writeAll(fd,isUserFd,buffer,0,buffer.byteLength,position,callback);
+writeAll(fd,isUserFd,buffer,0,buffer.byteLength,callback);
 }
 }
 
@@ -1307,15 +1303,11 @@ function writeFileSync(path, data, options) {
 }
 letoffset=0;
 letlength=data.byteLength;
-letposition=(/a/.test(flag)||isUserFd) ? null : 0;
 try{
 while(length>0){
-constwritten=fs.writeSync(fd,data,offset,length,position);
+constwritten=fs.writeSync(fd,data,offset,length);
 offset+=written;
 length-=written;
-if(position!==null){
-position+=written;
-}
 }
 }finally{
 if(!isUserFd)fs.closeSync(fd);