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| author | Filipe Manco <filipe.manco@neclab.eu> | 2016-09-15 18:10:46 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-09-17 16:56:02 +0300 |
| commit | cce94483e47e8e3d74cf4475dea33f9fd4b6ad9f (patch) | |
| tree | 319883b04cf525b1ab41a6dd6d3f1f5df97443ec | |
| parent | 4253ef8f6f81405e65304eef5a5b182c32dec915 (diff) | |
| download | linux-cce94483e47e8e3d74cf4475dea33f9fd4b6ad9f.tar.xz | |
xen-netback: fix error handling on netback_probe()
In case of error during netback_probe() (e.g. an entry missing on the
xenstore) netback_remove() is called on the new device, which will set
the device backend state to XenbusStateClosed by calling
set_backend_state(). However, the backend state wasn't initialized by
netback_probe() at this point, which will cause and invalid transaction
and set_backend_state() to BUG().
Initialize the backend state at the beginning of netback_probe() to
XenbusStateInitialising, and create two new valid state transitions on
set_backend_state(), from XenbusStateInitialising to XenbusStateClosed,
and from XenbusStateInitialising to XenbusStateInitWait.
Signed-off-by: Filipe Manco <filipe.manco@neclab.eu>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/xen-netback/xenbus.c | 46 |
1 files changed, 30 insertions, 16 deletions
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 6a31f2610c23..daf4c7867102 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -271,6 +271,11 @@ static int netback_probe(struct xenbus_device *dev, be->dev = dev; dev_set_drvdata(&dev->dev, be); + be->state = XenbusStateInitialising; + err = xenbus_switch_state(dev, XenbusStateInitialising); + if (err) + goto fail; + sg = 1; do { @@ -383,11 +388,6 @@ static int netback_probe(struct xenbus_device *dev, be->hotplug_script = script; - err = xenbus_switch_state(dev, XenbusStateInitWait); - if (err) - goto fail; - - be->state = XenbusStateInitWait; /* This kicks hotplug scripts, so do it immediately. */ err = backend_create_xenvif(be); @@ -492,20 +492,20 @@ static inline void backend_switch_state(struct backend_info *be, /* Handle backend state transitions: * - * The backend state starts in InitWait and the following transitions are + * The backend state starts in Initialising and the following transitions are * allowed. * - * InitWait -> Connected - * - * ^ \ | - * | \ | - * | \ | - * | \ | - * | \ | - * | \ | - * | V V + * Initialising -> InitWait -> Connected + * \ + * \ ^ \ | + * \ | \ | + * \ | \ | + * \ | \ | + * \ | \ | + * \ | \ | + * V | V V * - * Closed <-> Closing + * Closed <-> Closing * * The state argument specifies the eventual state of the backend and the * function transitions to that state via the shortest path. @@ -515,6 +515,20 @@ static void set_backend_state(struct backend_info *be, { while (be->state != state) { switch (be->state) { + case XenbusStateInitialising: + switch (state) { + case XenbusStateInitWait: + case XenbusStateConnected: + case XenbusStateClosing: + backend_switch_state(be, XenbusStateInitWait); + break; + case XenbusStateClosed: + backend_switch_state(be, XenbusStateClosed); + break; + default: + BUG(); + } + break; case XenbusStateClosed: switch (state) { case XenbusStateInitWait: |