101 lines
1.7 KiB
C
101 lines
1.7 KiB
C
#include <u.h>
|
|
#include <lib9.h>
|
|
#include <thread.h>
|
|
#include "dat.h"
|
|
#include "fns.h"
|
|
|
|
Dev *devs;
|
|
|
|
void
|
|
devwork(void *v)
|
|
{
|
|
Dev *d;
|
|
Buf *b;
|
|
Channel *r;
|
|
uint8_t buf[BLOCK];
|
|
|
|
d = v;
|
|
for(;;){
|
|
qlock(&d->workl);
|
|
while(d->work.wnext == &d->work)
|
|
rsleep(&d->workr);
|
|
b = d->work.wnext;
|
|
b->wnext->wprev = b->wprev;
|
|
b->wprev->wnext = b->wnext;
|
|
b->wnext = b->wprev = nil;
|
|
qunlock(&d->workl);
|
|
if(b->d == nil) /* this is a sync request */
|
|
goto reply;
|
|
if(b->off >= d->size){
|
|
b->error = Einval;
|
|
goto reply;
|
|
}
|
|
b->error = nil;
|
|
if(b->op & BWRITE){
|
|
memset(buf, 0, sizeof(buf));
|
|
pack(b, buf);
|
|
if(pwrite(d->fd, buf, BLOCK, b->off*BLOCK) < BLOCK){
|
|
dprint("write: %r\n");
|
|
b->error = Eio;
|
|
}
|
|
}else{
|
|
int n, m;
|
|
|
|
for(n = 0; n < BLOCK; n += m){
|
|
m = pread(d->fd, buf+n, BLOCK-n, b->off*BLOCK+n);
|
|
if(m < 0)
|
|
dprint("read: %r\n");
|
|
if(m <= 0)
|
|
break;
|
|
}
|
|
if(n < BLOCK)
|
|
b->error = Eio;
|
|
else
|
|
unpack(b, buf);
|
|
}
|
|
reply:
|
|
r = b->resp;
|
|
b->resp = nil;
|
|
if(r != nil)
|
|
send(r, &b);
|
|
}
|
|
}
|
|
|
|
Dev *
|
|
newdev(char *file)
|
|
{
|
|
Dev *d, **e;
|
|
Dir *dir;
|
|
Buf *b;
|
|
|
|
d = emalloc(sizeof(*d));
|
|
d->fd = open(file, ORDWR);
|
|
if(d->fd < 0){
|
|
free(d);
|
|
return nil;
|
|
}
|
|
dir = dirfstat(d->fd);
|
|
if(dir == nil){
|
|
error:
|
|
close(d->fd);
|
|
free(d);
|
|
return nil;
|
|
}
|
|
d->size = dir->length / BLOCK;
|
|
free(dir);
|
|
if(d->size == 0){
|
|
werrstr("device file too short");
|
|
goto error;
|
|
}
|
|
d->name = estrdup(file);
|
|
for(b = d->buf; b < d->buf + BUFHASH + 1; b++)
|
|
b->dnext = b->dprev = b;
|
|
d->workr.l = &d->workl;
|
|
d->work.wnext = d->work.wprev = &d->work;
|
|
proccreate(devwork, d, mainstacksize);
|
|
for(e = &devs; *e != nil; e = &(*e)->next)
|
|
;
|
|
*e = d;
|
|
return d;
|
|
}
|