Re: [fuse-devel] Kernel oops in fuse_send_readpages()

[Miklos S. <mi...@sz...>]

> I constantly get an oops while attempting to do parallel builds,
> using make -j3, on a dualcore (Athlon X2) system. The filesystem in
> question is encfs 1.2.5, although it probably is a fuse-only
> problem, since it crashes inside the kernel. The kernel is a vanilla
> 2.6.16.1, SMP, with both preemption and BKL preemption turned
> off. The libfuse2 version is 2.5.2.
> 
> That oops does not happen when I do a non-parallel build, using just
> make without -j. It also never happens when I try same parallel
> build on a non-SMP kernel. So it seems like an SMP-only problem.

Thanks for the report.

Can you please try the attached patch?

I'm not 100% sure that my analysis is correct, so I'm very interested
in your results.

Thanks,
Miklos

Index: linux/fs/fuse/file.c
===================================================================
--- linux.orig/fs/fuse/file.c	2006-03-31 14:00:35.000000000 +0200
+++ linux/fs/fuse/file.c	2006-03-31 14:04:30.000000000 +0200
@@ -397,8 +397,12 @@ static int fuse_readpages(struct file *f
 		return -EINTR;
 
 	err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
-	if (!err)
-		fuse_send_readpages(data.req, file, inode);
+	if (!err) {
+		if (data.req->num_pages)
+			fuse_send_readpages(data.req, file, inode);
+		else
+			fuse_put_request(fc, data.req);
+	}
 	return err;
 }