[PATCH v4 2/3] xen: modify xenstore watch event interface
From: Juergen Gross
Date: Thu Feb 09 2017 - 08:56:29 EST
Today a Xenstore watch event is delivered via a callback function
declared as:
void (*callback)(struct xenbus_watch *,
const char **vec, unsigned int len);
As all watch events only ever come with two parameters (path and token)
changing the prototype to:
void (*callback)(struct xenbus_watch *,
const char *path, const char *token);
is the natural thing to do.
Apply this change and adapt all users.
Cc: konrad.wilk@xxxxxxxxxx
Cc: roger.pau@xxxxxxxxxx
Cc: wei.liu2@xxxxxxxxxx
Cc: paul.durrant@xxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
Reviewed-by: Wei Liu <wei.liu2@xxxxxxxxxx>
Reviewed-by: Roger Pau Monnà <roger.pau@xxxxxxxxxx>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
---
drivers/block/xen-blkback/xenbus.c | 6 +++---
drivers/net/xen-netback/xenbus.c | 8 ++++----
drivers/xen/cpu_hotplug.c | 5 ++---
drivers/xen/manage.c | 6 +++---
drivers/xen/xen-balloon.c | 2 +-
drivers/xen/xen-pciback/xenbus.c | 2 +-
drivers/xen/xenbus/xenbus.h | 6 +++---
drivers/xen/xenbus/xenbus_client.c | 4 ++--
drivers/xen/xenbus/xenbus_dev_frontend.c | 21 ++++++++-------------
drivers/xen/xenbus/xenbus_probe.c | 11 ++++-------
drivers/xen/xenbus/xenbus_probe_backend.c | 8 ++++----
drivers/xen/xenbus/xenbus_probe_frontend.c | 14 +++++++-------
drivers/xen/xenbus/xenbus_xs.c | 29 ++++++++++++++---------------
include/xen/xenbus.h | 6 +++---
14 files changed, 59 insertions(+), 69 deletions(-)
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 415e79b..8fe61b5 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -38,8 +38,8 @@ struct backend_info {
static struct kmem_cache *xen_blkif_cachep;
static void connect(struct backend_info *);
static int connect_ring(struct backend_info *);
-static void backend_changed(struct xenbus_watch *, const char **,
- unsigned int);
+static void backend_changed(struct xenbus_watch *, const char *,
+ const char *);
static void xen_blkif_free(struct xen_blkif *blkif);
static void xen_vbd_free(struct xen_vbd *vbd);
@@ -661,7 +661,7 @@ static int xen_blkbk_probe(struct xenbus_device *dev,
* ready, connect.
*/
static void backend_changed(struct xenbus_watch *watch,
- const char **vec, unsigned int len)
+ const char *path, const char *token)
{
int err;
unsigned major;
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 85b742e..bb854f9 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -734,7 +734,7 @@ static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
}
static void xen_net_rate_changed(struct xenbus_watch *watch,
- const char **vec, unsigned int len)
+ const char *path, const char *token)
{
struct xenvif *vif = container_of(watch, struct xenvif, credit_watch);
struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
@@ -791,7 +791,7 @@ static void xen_unregister_credit_watch(struct xenvif *vif)
}
static void xen_mcast_ctrl_changed(struct xenbus_watch *watch,
- const char **vec, unsigned int len)
+ const char *path, const char *token)
{
struct xenvif *vif = container_of(watch, struct xenvif,
mcast_ctrl_watch);
@@ -866,8 +866,8 @@ static void unregister_hotplug_status_watch(struct backend_info *be)
}
static void hotplug_status_changed(struct xenbus_watch *watch,
- const char **vec,
- unsigned int vec_size)
+ const char *path,
+ const char *token)
{
struct backend_info *be = container_of(watch,
struct backend_info,
diff --git a/drivers/xen/cpu_hotplug.c b/drivers/xen/cpu_hotplug.c
index 5676aef..7a4daa2 100644
--- a/drivers/xen/cpu_hotplug.c
+++ b/drivers/xen/cpu_hotplug.c
@@ -68,13 +68,12 @@ static void vcpu_hotplug(unsigned int cpu)
}
static void handle_vcpu_hotplug_event(struct xenbus_watch *watch,
- const char **vec, unsigned int len)
+ const char *path, const char *token)
{
unsigned int cpu;
char *cpustr;
- const char *node = vec[XS_WATCH_PATH];
- cpustr = strstr(node, "cpu/");
+ cpustr = strstr(path, "cpu/");
if (cpustr != NULL) {
sscanf(cpustr, "cpu/%u", &cpu);
vcpu_hotplug(cpu);
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index 26e5e85..ca62c09 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -218,7 +218,7 @@ static struct shutdown_handler shutdown_handlers[] = {
};
static void shutdown_handler(struct xenbus_watch *watch,
- const char **vec, unsigned int len)
+ const char *path, const char *token)
{
char *str;
struct xenbus_transaction xbt;
@@ -266,8 +266,8 @@ static void shutdown_handler(struct xenbus_watch *watch,
}
#ifdef CONFIG_MAGIC_SYSRQ
-static void sysrq_handler(struct xenbus_watch *watch, const char **vec,
- unsigned int len)
+static void sysrq_handler(struct xenbus_watch *watch, const char *path,
+ const char *token)
{
char sysrq_key = '\0';
struct xenbus_transaction xbt;
diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c
index 79865b8..e7715cb 100644
--- a/drivers/xen/xen-balloon.c
+++ b/drivers/xen/xen-balloon.c
@@ -55,7 +55,7 @@ static int register_balloon(struct device *dev);
/* React to a change in the target key */
static void watch_target(struct xenbus_watch *watch,
- const char **vec, unsigned int len)
+ const char *path, const char *token)
{
unsigned long long new_target;
int err;
diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index 3f0aee0..3814b44 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -652,7 +652,7 @@ static int xen_pcibk_setup_backend(struct xen_pcibk_device *pdev)
}
static void xen_pcibk_be_watch(struct xenbus_watch *watch,
- const char **vec, unsigned int len)
+ const char *path, const char *token)
{
struct xen_pcibk_device *pdev =
container_of(watch, struct xen_pcibk_device, be_watch);
diff --git a/drivers/xen/xenbus/xenbus.h b/drivers/xen/xenbus/xenbus.h
index a6b007d..5199527 100644
--- a/drivers/xen/xenbus/xenbus.h
+++ b/drivers/xen/xenbus/xenbus.h
@@ -40,8 +40,8 @@ struct xen_bus_type {
int (*get_bus_id)(char bus_id[XEN_BUS_ID_SIZE], const char *nodename);
int (*probe)(struct xen_bus_type *bus, const char *type,
const char *dir);
- void (*otherend_changed)(struct xenbus_watch *watch, const char **vec,
- unsigned int len);
+ void (*otherend_changed)(struct xenbus_watch *watch, const char *path,
+ const char *token);
struct bus_type bus;
};
@@ -84,7 +84,7 @@ int xenbus_dev_resume(struct device *dev);
int xenbus_dev_cancel(struct device *dev);
void xenbus_otherend_changed(struct xenbus_watch *watch,
- const char **vec, unsigned int len,
+ const char *path, const char *token,
int ignore_on_shutdown);
int xenbus_read_otherend_details(struct xenbus_device *xendev,
diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
index 23edf53..9586c24 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -115,7 +115,7 @@ EXPORT_SYMBOL_GPL(xenbus_strstate);
int xenbus_watch_path(struct xenbus_device *dev, const char *path,
struct xenbus_watch *watch,
void (*callback)(struct xenbus_watch *,
- const char **, unsigned int))
+ const char *, const char *))
{
int err;
@@ -153,7 +153,7 @@ EXPORT_SYMBOL_GPL(xenbus_watch_path);
int xenbus_watch_pathfmt(struct xenbus_device *dev,
struct xenbus_watch *watch,
void (*callback)(struct xenbus_watch *,
- const char **, unsigned int),
+ const char *, const char *),
const char *pathfmt, ...)
{
int err;
diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c
index e2bc9b3..e4b9847 100644
--- a/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -258,26 +258,23 @@ static struct watch_adapter *alloc_watch_adapter(const char *path,
}
static void watch_fired(struct xenbus_watch *watch,
- const char **vec,
- unsigned int len)
+ const char *path,
+ const char *token)
{
struct watch_adapter *adap;
struct xsd_sockmsg hdr;
- const char *path, *token;
- int path_len, tok_len, body_len, data_len = 0;
+ const char *token_caller;
+ int path_len, tok_len, body_len;
int ret;
LIST_HEAD(staging_q);
adap = container_of(watch, struct watch_adapter, watch);
- path = vec[XS_WATCH_PATH];
- token = adap->token;
+ token_caller = adap->token;
path_len = strlen(path) + 1;
- tok_len = strlen(token) + 1;
- if (len > 2)
- data_len = vec[len] - vec[2] + 1;
- body_len = path_len + tok_len + data_len;
+ tok_len = strlen(token_caller) + 1;
+ body_len = path_len + tok_len;
hdr.type = XS_WATCH_EVENT;
hdr.len = body_len;
@@ -288,9 +285,7 @@ static void watch_fired(struct xenbus_watch *watch,
if (!ret)
ret = queue_reply(&staging_q, path, path_len);
if (!ret)
- ret = queue_reply(&staging_q, token, tok_len);
- if (!ret && len > 2)
- ret = queue_reply(&staging_q, vec[2], data_len);
+ ret = queue_reply(&staging_q, token_caller, tok_len);
if (!ret) {
/* success: pass reply list onto watcher */
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 6baffbb..74888ca 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -169,7 +169,7 @@ int xenbus_read_otherend_details(struct xenbus_device *xendev,
EXPORT_SYMBOL_GPL(xenbus_read_otherend_details);
void xenbus_otherend_changed(struct xenbus_watch *watch,
- const char **vec, unsigned int len,
+ const char *path, const char *token,
int ignore_on_shutdown)
{
struct xenbus_device *dev =
@@ -180,18 +180,15 @@ void xenbus_otherend_changed(struct xenbus_watch *watch,
/* Protect us against watches firing on old details when the otherend
details change, say immediately after a resume. */
if (!dev->otherend ||
- strncmp(dev->otherend, vec[XS_WATCH_PATH],
- strlen(dev->otherend))) {
- dev_dbg(&dev->dev, "Ignoring watch at %s\n",
- vec[XS_WATCH_PATH]);
+ strncmp(dev->otherend, path, strlen(dev->otherend))) {
+ dev_dbg(&dev->dev, "Ignoring watch at %s\n", path);
return;
}
state = xenbus_read_driver_state(dev->otherend);
dev_dbg(&dev->dev, "state is %d, (%s), %s, %s\n",
- state, xenbus_strstate(state), dev->otherend_watch.node,
- vec[XS_WATCH_PATH]);
+ state, xenbus_strstate(state), dev->otherend_watch.node, path);
/*
* Ignore xenbus transitions during shutdown. This prevents us doing
diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c
index f46b4dc..b0bed4f 100644
--- a/drivers/xen/xenbus/xenbus_probe_backend.c
+++ b/drivers/xen/xenbus/xenbus_probe_backend.c
@@ -181,9 +181,9 @@ static int xenbus_probe_backend(struct xen_bus_type *bus, const char *type,
}
static void frontend_changed(struct xenbus_watch *watch,
- const char **vec, unsigned int len)
+ const char *path, const char *token)
{
- xenbus_otherend_changed(watch, vec, len, 0);
+ xenbus_otherend_changed(watch, path, token, 0);
}
static struct xen_bus_type xenbus_backend = {
@@ -204,11 +204,11 @@ static struct xen_bus_type xenbus_backend = {
};
static void backend_changed(struct xenbus_watch *watch,
- const char **vec, unsigned int len)
+ const char *path, const char *token)
{
DPRINTK("");
- xenbus_dev_changed(vec[XS_WATCH_PATH], &xenbus_backend);
+ xenbus_dev_changed(path, &xenbus_backend);
}
static struct xenbus_watch be_watch = {
diff --git a/drivers/xen/xenbus/xenbus_probe_frontend.c b/drivers/xen/xenbus/xenbus_probe_frontend.c
index d7b77a6..19e45ce 100644
--- a/drivers/xen/xenbus/xenbus_probe_frontend.c
+++ b/drivers/xen/xenbus/xenbus_probe_frontend.c
@@ -86,9 +86,9 @@ static int xenbus_uevent_frontend(struct device *_dev,
static void backend_changed(struct xenbus_watch *watch,
- const char **vec, unsigned int len)
+ const char *path, const char *token)
{
- xenbus_otherend_changed(watch, vec, len, 1);
+ xenbus_otherend_changed(watch, path, token, 1);
}
static void xenbus_frontend_delayed_resume(struct work_struct *w)
@@ -153,11 +153,11 @@ static struct xen_bus_type xenbus_frontend = {
};
static void frontend_changed(struct xenbus_watch *watch,
- const char **vec, unsigned int len)
+ const char *path, const char *token)
{
DPRINTK("");
- xenbus_dev_changed(vec[XS_WATCH_PATH], &xenbus_frontend);
+ xenbus_dev_changed(path, &xenbus_frontend);
}
@@ -332,13 +332,13 @@ static DECLARE_WAIT_QUEUE_HEAD(backend_state_wq);
static int backend_state;
static void xenbus_reset_backend_state_changed(struct xenbus_watch *w,
- const char **v, unsigned int l)
+ const char *path, const char *token)
{
- if (xenbus_scanf(XBT_NIL, v[XS_WATCH_PATH], "", "%i",
+ if (xenbus_scanf(XBT_NIL, path, "", "%i",
&backend_state) != 1)
backend_state = XenbusStateUnknown;
printk(KERN_DEBUG "XENBUS: backend %s %s\n",
- v[XS_WATCH_PATH], xenbus_strstate(backend_state));
+ path, xenbus_strstate(backend_state));
wake_up(&backend_state_wq);
}
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index 4c49d87..ebc768f 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -64,8 +64,8 @@ struct xs_stored_msg {
/* Queued watch events. */
struct {
struct xenbus_watch *handle;
- char **vec;
- unsigned int vec_size;
+ const char *path;
+ const char *token;
} watch;
} u;
};
@@ -765,7 +765,7 @@ void unregister_xenbus_watch(struct xenbus_watch *watch)
if (msg->u.watch.handle != watch)
continue;
list_del(&msg->list);
- kfree(msg->u.watch.vec);
+ kfree(msg->u.watch.path);
kfree(msg);
}
spin_unlock(&watch_events_lock);
@@ -833,11 +833,10 @@ static int xenwatch_thread(void *unused)
if (ent != &watch_events) {
msg = list_entry(ent, struct xs_stored_msg, list);
- msg->u.watch.handle->callback(
- msg->u.watch.handle,
- (const char **)msg->u.watch.vec,
- msg->u.watch.vec_size);
- kfree(msg->u.watch.vec);
+ msg->u.watch.handle->callback(msg->u.watch.handle,
+ msg->u.watch.path,
+ msg->u.watch.token);
+ kfree(msg->u.watch.path);
kfree(msg);
}
@@ -903,24 +902,24 @@ static int process_msg(void)
body[msg->hdr.len] = '\0';
if (msg->hdr.type == XS_WATCH_EVENT) {
- msg->u.watch.vec = split(body, msg->hdr.len,
- &msg->u.watch.vec_size);
- if (IS_ERR(msg->u.watch.vec)) {
- err = PTR_ERR(msg->u.watch.vec);
+ if (count_strings(body, msg->hdr.len) != 2) {
+ err = -EINVAL;
kfree(msg);
+ kfree(body);
goto out;
}
+ msg->u.watch.path = (const char *)body;
+ msg->u.watch.token = (const char *)strchr(body, '\0') + 1;
spin_lock(&watches_lock);
- msg->u.watch.handle = find_watch(
- msg->u.watch.vec[XS_WATCH_TOKEN]);
+ msg->u.watch.handle = find_watch(msg->u.watch.token);
if (msg->u.watch.handle != NULL) {
spin_lock(&watch_events_lock);
list_add_tail(&msg->list, &watch_events);
wake_up(&watch_events_waitq);
spin_unlock(&watch_events_lock);
} else {
- kfree(msg->u.watch.vec);
+ kfree(body);
kfree(msg);
}
spin_unlock(&watches_lock);
diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h
index 98f73a2..869c816 100644
--- a/include/xen/xenbus.h
+++ b/include/xen/xenbus.h
@@ -61,7 +61,7 @@ struct xenbus_watch
/* Callback (executed in a process context with no locks held). */
void (*callback)(struct xenbus_watch *,
- const char **vec, unsigned int len);
+ const char *path, const char *token);
};
@@ -193,11 +193,11 @@ void xenbus_probe(struct work_struct *);
int xenbus_watch_path(struct xenbus_device *dev, const char *path,
struct xenbus_watch *watch,
void (*callback)(struct xenbus_watch *,
- const char **, unsigned int));
+ const char *, const char *));
__printf(4, 5)
int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
void (*callback)(struct xenbus_watch *,
- const char **, unsigned int),
+ const char *, const char *),
const char *pathfmt, ...);
int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
--
2.10.2