1 d3df3087 2003-12-06 devnull /* Copyright (C) 2003 Russ Cox, Massachusetts Institute of Technology */
 2 d3df3087 2003-12-06 devnull /* See COPYRIGHT */
 3 d3df3087 2003-12-06 devnull 
 4 d3df3087 2003-12-06 devnull #include <u.h>
 5 d3df3087 2003-12-06 devnull #include <libc.h>
 6 d3df3087 2003-12-06 devnull #include <fcall.h>
 7 d3df3087 2003-12-06 devnull #include <fs.h>
 8 d3df3087 2003-12-06 devnull #include "fsimpl.h"
 9 d3df3087 2003-12-06 devnull 
10 d3df3087 2003-12-06 devnull long
11 d3df3087 2003-12-06 devnull fspread(Fid *fid, void *buf, long n, vlong offset)
12 d3df3087 2003-12-06 devnull {
13 d3df3087 2003-12-06 devnull 	Fcall tx, rx;
14 d3df3087 2003-12-06 devnull 	void *freep;
15 5a8e63b2 2004-02-29 devnull 	uint msize;
16 d3df3087 2003-12-06 devnull 
17 5a8e63b2 2004-02-29 devnull 	msize = fid->fs->msize - IOHDRSZ;
18 5a8e63b2 2004-02-29 devnull fprint(2, "n %d msize %d\n", n, msize);
19 5a8e63b2 2004-02-29 devnull 	if(n > msize)
20 5a8e63b2 2004-02-29 devnull 		n = msize;
21 d3df3087 2003-12-06 devnull 	tx.type = Tread;
22 ceb04770 2003-12-09 devnull 	tx.fid = fid->fid;
23 d3df3087 2003-12-06 devnull 	if(offset == -1){
24 d3df3087 2003-12-06 devnull 		qlock(&fid->lk);
25 d3df3087 2003-12-06 devnull 		tx.offset = fid->offset;
26 d3df3087 2003-12-06 devnull 		qunlock(&fid->lk);
27 d3df3087 2003-12-06 devnull 	}else
28 d3df3087 2003-12-06 devnull 		tx.offset = offset;
29 d3df3087 2003-12-06 devnull 	tx.count = n;
30 d3df3087 2003-12-06 devnull 
31 15680d56 2004-03-05 devnull 	if(fsrpc(fid->fs, &tx, &rx, &freep) < 0)
32 15680d56 2004-03-05 devnull 		return -1;
33 d3df3087 2003-12-06 devnull 	if(rx.type == Rerror){
34 d3df3087 2003-12-06 devnull 		werrstr("%s", rx.ename);
35 d3df3087 2003-12-06 devnull 		free(freep);
36 d3df3087 2003-12-06 devnull 		return -1;
37 d3df3087 2003-12-06 devnull 	}
38 d3df3087 2003-12-06 devnull 	if(rx.count){
39 d3df3087 2003-12-06 devnull 		memmove(buf, rx.data, rx.count);
40 d3df3087 2003-12-06 devnull 		if(offset == -1){
41 d3df3087 2003-12-06 devnull 			qlock(&fid->lk);
42 ceb04770 2003-12-09 devnull 			fid->offset += rx.count;
43 d3df3087 2003-12-06 devnull 			qunlock(&fid->lk);
44 d3df3087 2003-12-06 devnull 		}
45 d3df3087 2003-12-06 devnull 	}
46 d3df3087 2003-12-06 devnull 	free(freep);
47 d3df3087 2003-12-06 devnull 	
48 d3df3087 2003-12-06 devnull 	return rx.count;
49 d3df3087 2003-12-06 devnull }
50 d3df3087 2003-12-06 devnull 
51 d3df3087 2003-12-06 devnull long
52 d3df3087 2003-12-06 devnull fsread(Fid *fid, void *buf, long n)
53 d3df3087 2003-12-06 devnull {
54 d3df3087 2003-12-06 devnull 	return fspread(fid, buf, n, -1);
55 d3df3087 2003-12-06 devnull }