Return partially filled buffer for non-blocking read(2)

in non-immediate mode.

PR:		kern/143855
This commit is contained in:
Jung-uk Kim 2010-02-20 00:19:21 +00:00
parent 9b3e11b84b
commit 8df67d77ed
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=204105

View File

@ -664,8 +664,9 @@ static int
bpfread(struct cdev *dev, struct uio *uio, int ioflag)
{
struct bpf_d *d;
int timed_out;
int error;
int non_block;
int timed_out;
error = devfs_get_cdevpriv((void **)&d);
if (error != 0)
@ -678,6 +679,8 @@ bpfread(struct cdev *dev, struct uio *uio, int ioflag)
if (uio->uio_resid != d->bd_bufsize)
return (EINVAL);
non_block = ((ioflag & O_NONBLOCK) != 0);
BPFD_LOCK(d);
d->bd_pid = curthread->td_proc->p_pid;
if (d->bd_bufmode != BPF_BUFMODE_BUFFER) {
@ -694,14 +697,20 @@ bpfread(struct cdev *dev, struct uio *uio, int ioflag)
* have arrived to fill the store buffer.
*/
while (d->bd_hbuf == NULL) {
if ((d->bd_immediate || timed_out) && d->bd_slen != 0) {
if (d->bd_slen != 0) {
/*
* A packet(s) either arrived since the previous
* read or arrived while we were asleep.
* Rotate the buffers and return what's here.
*/
ROTATE_BUFFERS(d);
break;
if (d->bd_immediate || non_block || timed_out) {
/*
* Rotate the buffers and return what's here
* if we are in immediate mode, non-blocking
* flag is set, or this descriptor timed out.
*/
ROTATE_BUFFERS(d);
break;
}
}
/*
@ -715,7 +724,7 @@ bpfread(struct cdev *dev, struct uio *uio, int ioflag)
return (ENXIO);
}
if (ioflag & O_NONBLOCK) {
if (non_block) {
BPFD_UNLOCK(d);
return (EWOULDBLOCK);
}