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authorStefano Garzarella <sgarzare@redhat.com>2023-09-25 12:30:57 +0200
committerDavid S. Miller <davem@davemloft.net>2023-10-04 08:26:48 +0100
commit7aed44babc7f97e82b38e9a68515e699692cc100 (patch)
treee527c0c689861df102dd83a329120e48500ac374 /drivers/vhost
parenta0c55bba0d0d0b5591083f65f830940d8ae63f31 (diff)
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vringh: don't use vringh_kiov_advance() in vringh_iov_xfer()
In the while loop of vringh_iov_xfer(), `partlen` could be 0 if one of the `iov` has 0 lenght. In this case, we should skip the iov and go to the next one. But calling vringh_kiov_advance() with 0 lenght does not cause the advancement, since it returns immediately if asked to advance by 0 bytes. Let's restore the code that was there before commit b8c06ad4d67d ("vringh: implement vringh_kiov_advance()"), avoiding using vringh_kiov_advance(). Fixes: b8c06ad4d67d ("vringh: implement vringh_kiov_advance()") Cc: stable@vger.kernel.org Reported-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/vhost')
-rw-r--r--drivers/vhost/vringh.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index 955d938eb663..7b8fd977f71c 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -123,8 +123,18 @@ static inline ssize_t vringh_iov_xfer(struct vringh *vrh,
done += partlen;
len -= partlen;
ptr += partlen;
+ iov->consumed += partlen;
+ iov->iov[iov->i].iov_len -= partlen;
+ iov->iov[iov->i].iov_base += partlen;
- vringh_kiov_advance(iov, partlen);
+ if (!iov->iov[iov->i].iov_len) {
+ /* Fix up old iov element then increment. */
+ iov->iov[iov->i].iov_len = iov->consumed;
+ iov->iov[iov->i].iov_base -= iov->consumed;
+
+ iov->consumed = 0;
+ iov->i++;
+ }
}
return done;
}