1 daefa1a9 2005-01-18 devnull #include <u.h>
 2 daefa1a9 2005-01-18 devnull #include <libc.h>
 3 daefa1a9 2005-01-18 devnull #include <fcall.h>
 4 daefa1a9 2005-01-18 devnull #include <9pclient.h>
 5 daefa1a9 2005-01-18 devnull #include "fsimpl.h"
 6 daefa1a9 2005-01-18 devnull 
 7 daefa1a9 2005-01-18 devnull vlong
 8 daefa1a9 2005-01-18 devnull fsseek(CFid *fid, vlong n, int whence)
 9 daefa1a9 2005-01-18 devnull {
10 daefa1a9 2005-01-18 devnull 	Dir *d;
11 daefa1a9 2005-01-18 devnull 
12 daefa1a9 2005-01-18 devnull 	switch(whence){
13 daefa1a9 2005-01-18 devnull 	case 0:
14 daefa1a9 2005-01-18 devnull 		qlock(&fid->lk);
15 daefa1a9 2005-01-18 devnull 		fid->offset = n;
16 daefa1a9 2005-01-18 devnull 		qunlock(&fid->lk);
17 daefa1a9 2005-01-18 devnull 		break;
18 daefa1a9 2005-01-18 devnull 	case 1:
19 daefa1a9 2005-01-18 devnull 		qlock(&fid->lk);
20 daefa1a9 2005-01-18 devnull 		n += fid->offset;
21 daefa1a9 2005-01-18 devnull 		if(n < 0){
22 daefa1a9 2005-01-18 devnull 			qunlock(&fid->lk);
23 daefa1a9 2005-01-18 devnull 			werrstr("negative offset");
24 daefa1a9 2005-01-18 devnull 			return -1;
25 daefa1a9 2005-01-18 devnull 		}
26 daefa1a9 2005-01-18 devnull 		fid->offset = n;
27 daefa1a9 2005-01-18 devnull 		qunlock(&fid->lk);
28 daefa1a9 2005-01-18 devnull 		break;
29 daefa1a9 2005-01-18 devnull 	case 2:
30 daefa1a9 2005-01-18 devnull 		if((d = fsdirfstat(fid)) == nil)
31 daefa1a9 2005-01-18 devnull 			return -1;
32 daefa1a9 2005-01-18 devnull 		n += d->length;
33 daefa1a9 2005-01-18 devnull 		if(n < 0){
34 daefa1a9 2005-01-18 devnull 			werrstr("negative offset");
35 daefa1a9 2005-01-18 devnull 			return -1;
36 daefa1a9 2005-01-18 devnull 		}
37 daefa1a9 2005-01-18 devnull 		qlock(&fid->lk);
38 daefa1a9 2005-01-18 devnull 		fid->offset = n;
39 daefa1a9 2005-01-18 devnull 		qunlock(&fid->lk);
40 daefa1a9 2005-01-18 devnull 		break;
41 daefa1a9 2005-01-18 devnull 	default:
42 daefa1a9 2005-01-18 devnull 		werrstr("bad whence in fsseek");
43 daefa1a9 2005-01-18 devnull 		return -1;
44 daefa1a9 2005-01-18 devnull 	}
45 daefa1a9 2005-01-18 devnull 	return n;
46 daefa1a9 2005-01-18 devnull }