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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging] tools/xenstore: add read watch state for live update
commit c6fde653593cc6d21511819213e3cf7516f7cdcd
Author: Juergen Gross <jgross@xxxxxxxx>
AuthorDate: Wed Jan 13 14:00:20 2021 +0100
Commit: Juergen Gross <jgross@xxxxxxxx>
CommitDate: Thu Jan 21 17:31:50 2021 +0100
tools/xenstore: add read watch state for live update
Add reading the watch state records for live update.
This requires factoring out some of the add watch functionality into a
dedicated function.
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Paul Durrant <paul@xxxxxxx>
Acked-by: Wei Liu <wl@xxxxxxx>
---
tools/xenstore/xenstored_control.c | 2 +
tools/xenstore/xenstored_watch.c | 114 +++++++++++++++++++++++++++----------
tools/xenstore/xenstored_watch.h | 2 +
3 files changed, 88 insertions(+), 30 deletions(-)
diff --git a/tools/xenstore/xenstored_control.c
b/tools/xenstore/xenstored_control.c
index 287417de6b..b8195eed41 100644
--- a/tools/xenstore/xenstored_control.c
+++ b/tools/xenstore/xenstored_control.c
@@ -35,6 +35,7 @@ Interactive commands for Xen Store Daemon.
#include "xenstored_core.h"
#include "xenstored_control.h"
#include "xenstored_domain.h"
+#include "xenstored_watch.h"
/* Mini-OS only knows about MAP_ANON. */
#ifndef MAP_ANONYMOUS
@@ -542,6 +543,7 @@ void lu_read_state(void)
read_state_connection(ctx, head + 1);
break;
case XS_STATE_TYPE_WATCH:
+ read_state_watch(ctx, head + 1);
break;
case XS_STATE_TYPE_TA:
xprintf("live-update: ignore transaction record\n");
diff --git a/tools/xenstore/xenstored_watch.c b/tools/xenstore/xenstored_watch.c
index 9248f08bd9..db89e0141f 100644
--- a/tools/xenstore/xenstored_watch.c
+++ b/tools/xenstore/xenstored_watch.c
@@ -205,6 +205,62 @@ static int destroy_watch(void *_watch)
return 0;
}
+static int check_watch_path(struct connection *conn, const void *ctx,
+ char **path, bool *relative)
+{
+ /* Check if valid event. */
+ if (strstarts(*path, "@")) {
+ *relative = false;
+ if (strlen(*path) > XENSTORE_REL_PATH_MAX)
+ goto inval;
+ } else {
+ *relative = !strstarts(*path, "/");
+ *path = canonicalize(conn, ctx, *path);
+ if (!*path)
+ return errno;
+ if (!is_valid_nodename(*path))
+ goto inval;
+ }
+
+ return 0;
+
+ inval:
+ errno = EINVAL;
+ return errno;
+}
+
+static struct watch *add_watch(struct connection *conn, char *path, char
*token,
+ bool relative)
+{
+ struct watch *watch;
+
+ watch = talloc(conn, struct watch);
+ if (!watch)
+ goto nomem;
+ watch->node = talloc_strdup(watch, path);
+ watch->token = talloc_strdup(watch, token);
+ if (!watch->node || !watch->token)
+ goto nomem;
+
+ if (relative)
+ watch->relative_path = get_implicit_path(conn);
+ else
+ watch->relative_path = NULL;
+
+ INIT_LIST_HEAD(&watch->events);
+
+ domain_watch_inc(conn);
+ list_add_tail(&watch->list, &conn->watches);
+ talloc_set_destructor(watch, destroy_watch);
+
+ return watch;
+
+ nomem:
+ talloc_free(watch);
+ errno = ENOMEM;
+ return NULL;
+}
+
int do_watch(struct connection *conn, struct buffered_data *in)
{
struct watch *watch;
@@ -214,19 +270,9 @@ int do_watch(struct connection *conn, struct buffered_data
*in)
if (get_strings(in, vec, ARRAY_SIZE(vec)) != ARRAY_SIZE(vec))
return EINVAL;
- if (strstarts(vec[0], "@")) {
- relative = false;
- if (strlen(vec[0]) > XENSTORE_REL_PATH_MAX)
- return EINVAL;
- /* check if valid event */
- } else {
- relative = !strstarts(vec[0], "/");
- vec[0] = canonicalize(conn, in, vec[0]);
- if (!vec[0])
- return ENOMEM;
- if (!is_valid_nodename(vec[0]))
- return EINVAL;
- }
+ errno = check_watch_path(conn, in, &(vec[0]), &relative);
+ if (errno)
+ return errno;
/* Check for duplicates. */
list_for_each_entry(watch, &conn->watches, list) {
@@ -238,26 +284,11 @@ int do_watch(struct connection *conn, struct
buffered_data *in)
if (domain_watch(conn) > quota_nb_watch_per_domain)
return E2BIG;
- watch = talloc(conn, struct watch);
+ watch = add_watch(conn, vec[0], vec[1], relative);
if (!watch)
- return ENOMEM;
- watch->node = talloc_strdup(watch, vec[0]);
- watch->token = talloc_strdup(watch, vec[1]);
- if (!watch->node || !watch->token) {
- talloc_free(watch);
- return ENOMEM;
- }
- if (relative)
- watch->relative_path = get_implicit_path(conn);
- else
- watch->relative_path = NULL;
+ return errno;
- INIT_LIST_HEAD(&watch->events);
-
- domain_watch_inc(conn);
- list_add_tail(&watch->list, &conn->watches);
trace_create(watch, "watch");
- talloc_set_destructor(watch, destroy_watch);
send_ack(conn, XS_WATCH);
/* We fire once up front: simplifies clients and restart. */
@@ -338,6 +369,29 @@ const char *dump_state_watches(FILE *fp, struct connection
*conn,
return ret;
}
+void read_state_watch(const void *ctx, const void *state)
+{
+ const struct xs_state_watch *sw = state;
+ struct connection *conn;
+ char *path, *token;
+ bool relative;
+
+ conn = get_connection_by_id(sw->conn_id);
+ if (!conn)
+ barf("connection not found for read watch");
+
+ path = (char *)sw->data;
+ token = path + sw->path_length;
+
+ /* Don't check success, we want the relative information only. */
+ check_watch_path(conn, ctx, &path, &relative);
+ if (!path)
+ barf("allocation error for read watch");
+
+ if (!add_watch(conn, path, token, relative))
+ barf("error adding watch");
+}
+
/*
* Local variables:
* mode: C
diff --git a/tools/xenstore/xenstored_watch.h b/tools/xenstore/xenstored_watch.h
index 3d81645f45..0e693f0839 100644
--- a/tools/xenstore/xenstored_watch.h
+++ b/tools/xenstore/xenstored_watch.h
@@ -33,4 +33,6 @@ void conn_delete_all_watches(struct connection *conn);
const char *dump_state_watches(FILE *fp, struct connection *conn,
unsigned int conn_id);
+void read_state_watch(const void *ctx, const void *state);
+
#endif /* _XENSTORED_WATCH_H */
--
generated by git-patchbot for /home/xen/git/xen.git#staging
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