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| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2014-11-06 18:21:24 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-26 19:00:32 -0800 |
| commit | 649142074d86afebe0505431a93957505d244dd6 (patch) | |
| tree | 4e135e9056ba74312a3536c112c83531604a62de /drivers | |
| parent | 1a3c724afd07a485c7066140f67d466f39263dc6 (diff) | |
| download | lwn-649142074d86afebe0505431a93957505d244dd6.tar.gz lwn-649142074d86afebe0505431a93957505d244dd6.zip | |
Drivers: hv: vss: Introduce timeout for communication with userspace
In contrast with KVP there is no timeout when communicating with
userspace VSS daemon. In case it gets stuck performing freeze/thaw
operation no message will be sent to the host so it will take very
long (around 10 minutes) before backup fails. Introduce 10 second
timeout using schedule_delayed_work().
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/hv/hv_snapshot.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c index 34f14fddb666..21e51be74e6c 100644 --- a/drivers/hv/hv_snapshot.c +++ b/drivers/hv/hv_snapshot.c @@ -28,7 +28,7 @@ #define VSS_MINOR 0 #define VSS_VERSION (VSS_MAJOR << 16 | VSS_MINOR) - +#define VSS_USERSPACE_TIMEOUT (msecs_to_jiffies(10 * 1000)) /* * Global state maintained for transaction that is being processed. @@ -55,12 +55,24 @@ static const char vss_name[] = "vss_kernel_module"; static __u8 *recv_buffer; static void vss_send_op(struct work_struct *dummy); +static void vss_timeout_func(struct work_struct *dummy); + +static DECLARE_DELAYED_WORK(vss_timeout_work, vss_timeout_func); static DECLARE_WORK(vss_send_op_work, vss_send_op); /* * Callback when data is received from user mode. */ +static void vss_timeout_func(struct work_struct *dummy) +{ + /* + * Timeout waiting for userspace component to reply happened. + */ + pr_warn("VSS: timeout waiting for daemon to reply\n"); + vss_respond_to_host(HV_E_FAIL); +} + static void vss_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp) { @@ -76,7 +88,8 @@ vss_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp) return; } - vss_respond_to_host(vss_msg->error); + if (cancel_delayed_work_sync(&vss_timeout_work)) + vss_respond_to_host(vss_msg->error); } @@ -223,6 +236,8 @@ void hv_vss_onchannelcallback(void *context) case VSS_OP_FREEZE: case VSS_OP_THAW: schedule_work(&vss_send_op_work); + schedule_delayed_work(&vss_timeout_work, + VSS_USERSPACE_TIMEOUT); return; case VSS_OP_HOT_BACKUP: @@ -277,5 +292,6 @@ hv_vss_init(struct hv_util_service *srv) void hv_vss_deinit(void) { cn_del_callback(&vss_id); + cancel_delayed_work_sync(&vss_timeout_work); cancel_work_sync(&vss_send_op_work); } |