diff options
| author | Simon Gaiser <simon@invisiblethingslab.com> | 2018-03-15 03:43:20 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-19 08:56:21 +0200 |
| commit | 0319ce67b793e7fed0d828587e3edd8c6a80cc56 (patch) | |
| tree | 0a137cf86452db86b7af9dd440a8c1709d5f41e8 | |
| parent | 80f509d4919d5517b4b16c272df5d1cd39a8ea18 (diff) | |
xen: xenbus_dev_frontend: Fix XS_TRANSACTION_END handling
commit 2a22ee6c3ab1d761bc9c04f1e4117edd55b82f09 upstream.
Commit fd8aa9095a95 ("xen: optimize xenbus driver for multiple
concurrent xenstore accesses") made a subtle change to the semantic of
xenbus_dev_request_and_reply() and xenbus_transaction_end().
Before on an error response to XS_TRANSACTION_END
xenbus_dev_request_and_reply() would not decrement the active
transaction counter. But xenbus_transaction_end() has always counted the
transaction as finished regardless of the response.
The new behavior is that xenbus_dev_request_and_reply() and
xenbus_transaction_end() will always count the transaction as finished
regardless the response code (handled in xs_request_exit()).
But xenbus_dev_frontend tries to end a transaction on closing of the
device if the XS_TRANSACTION_END failed before. Trying to close the
transaction twice corrupts the reference count. So fix this by also
considering a transaction closed if we have sent XS_TRANSACTION_END once
regardless of the return code.
Cc: <stable@vger.kernel.org> # 4.11
Fixes: fd8aa9095a95 ("xen: optimize xenbus driver for multiple concurrent xenstore accesses")
Signed-off-by: Simon Gaiser <simon@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/xen/xenbus/xenbus_dev_frontend.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c index f3b089b7c0b6..d2edbc79384a 100644 --- a/drivers/xen/xenbus/xenbus_dev_frontend.c +++ b/drivers/xen/xenbus/xenbus_dev_frontend.c @@ -365,7 +365,7 @@ void xenbus_dev_queue_reply(struct xb_req_data *req) if (WARN_ON(rc)) goto out; } - } else if (req->msg.type == XS_TRANSACTION_END) { + } else if (req->type == XS_TRANSACTION_END) { trans = xenbus_get_transaction(u, req->msg.tx_id); if (WARN_ON(!trans)) goto out; |