Re: Re: [PATCH 2/2] [BUGFIX] virtio/console: Add pipe_lock/unlockfor splice_write
From: Yoshihiro YUNOMAE
Date: Fri Jul 19 2013 - 01:47:21 EST
Hi Amit,
(2013/07/19 14:23), Amit Shah wrote:
On (Fri) 19 Jul 2013 [08:19:32], Yoshihiro YUNOMAE wrote:
Add pipe_lock/unlock for splice_write to avoid oops by following competition:
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 8722656..4a28e4c 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -936,6 +936,7 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
* pipe->nrbufs == 0 means there are no data to transfer,
* so this returns just 0 for no data.
*/
+ pipe_lock(pipe);
if (!pipe->nrbufs)
return 0;
@@ -953,6 +954,7 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
sgl.sg = buf->sg;
sg_init_table(sgl.sg, sgl.size);
ret = __splice_from_pipe(pipe, &sd, pipe_to_sg);
+ pipe_unlock(pipe);
if (likely(ret > 0))
ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true);
You're not unlocking in all the error return cases.
Oh, sorry.
I'll resend a revised patch soon.
Thanks!
Yoshihiro YUNOMAE
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æåãæåïYUNOMAE Yoshihiroï
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Yoshihiro YUNOMAE
Software Platform Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: yoshihiro.yunomae.ez@xxxxxxxxxxx
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