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#include <u.h>
#include <libc.h>
#include <thread.h>
#include "dat.h"
#include "fns.h"
Dev *devs;
void
devwork(void *v)
{
Dev *d;
Buf *b;
Channel *r;
uchar 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;
}
seek(d->fd, b->off * BLOCK, 0);
b->error = nil;
if(b->op & BWRITE){
memset(buf, 0, sizeof(buf));
pack(b, buf);
if(write(d->fd, buf, BLOCK) < BLOCK){
dprint("hjfs: write: %r\n");
b->error = Eio;
}
}else{
if(readn(d->fd, buf, BLOCK) < 0){
dprint("hjfs: read: %r\n");
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;
}
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