Re: [regression?] distcc says: (dcc_pump_sendfile) ERROR: sendfilereturned 0? can't cope (bisected)

[Tom Zanussi]

On Wed, 2008-05-07 at 23:16 +0200, Jens Axboe wrote:
> On Wed, May 07 2008, Dan Williams wrote:
> > Hi Tom, Jens,
> > 
> > My build system started reporting these error messages recently.
> > Reverting commit c3270e577c18b3d0e984c3371493205a4807db9d on top of
> > 2.6.26-rc1 gets things working for me again.
> 
> Irk, that patch did scare me a bit (hence I asked Tom to double check as
> wel :-). I'll take a look in the morning, all test boxes are off at this
> point in time.
> 

I did, and it still looks ok to me, but obviously it's not, so I'll have
to do some more digging.

The only thing I can think of right now that might be a possible cause
would be in splice_direct_to_actor(), if we had an incomplete transfer,
the sd->pos returned and assigned would have the value set by the failed
actor().  Maybe something like the following would take care of that
case, but I haven't had a chance to test it yet - will do that tomorrow
night...

Tom

diff --git a/fs/splice.c b/fs/splice.c
index 633f58e..1bb3f34 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -986,7 +986,7 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
 
 	while (len) {
 		size_t read_len;
-		loff_t pos = sd->pos;
+		loff_t pos = sd->pos, prev_pos = pos;
 
 		ret = do_splice_to(in, &pos, pipe, len, flags);
 		if (unlikely(ret <= 0))
@@ -1001,8 +1001,10 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
 		 * could get stuck data in the internal pipe:
 		 */
 		ret = actor(pipe, sd);
-		if (unlikely(ret <= 0))
+		if (unlikely(ret <= 0)) {
+			sd->pos = prev_pos;
 			goto out_release;
+		}
 
 		bytes += ret;
 		len -= ret;


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/