[pve-devel] [PATCH cluster v11 1/5] add CFS_IPC_GET_GUEST_CONFIG_PROPERTIES method

[Dominik Csapak <d.csapak@proxmox.com>]

for getting multiple properties from the in memory config of the
guests in one go. Keep the existing IPC call as is for backward
compatibility and add this as separate, new one.

It basically behaves the same as
CFS_IPC_GET_GUEST_CONFIG_PROPERTY, but takes a list of properties
instead and returns multiple properties per guest.

The old way of getting a single property is now also done by
the new function, since it basically performs identically.

Here a short benchmark:

Setup:
PVE in a VM with cpu type host (12700k) and 4 cores
10000 typical configs with both 'lock' and 'tags' set at the end
and fairly long tags ('test-tag1,test-tag2,test-tag3')
(normal vm with a snapshot, ~1KiB)

i let it run 100 times each, times in ms

old code:

total time  time per iteration
1054.2      10.2

new code:

num props  total time  time per iter  function
2          1332.2      13.2           get_properties
1          1051.2      10.2           get_properties
2          2082.2      20.2           get_property (2 calls to get_property)
1          1034.2      10.2           get_property

so a call with the new code for one property is the same as with the
old code, and adding a second property only adds a bit of additional
time (in this case ~30%)

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
 data/src/cfs-ipc-ops.h |   2 +
 data/src/server.c      |  63 +++++++++++++
 data/src/status.c      | 207 +++++++++++++++++++++++++++++------------
 data/src/status.h      |   3 +
 4 files changed, 217 insertions(+), 58 deletions(-)

diff --git a/data/src/cfs-ipc-ops.h b/data/src/cfs-ipc-ops.h
index 003e233..249308d 100644
--- a/data/src/cfs-ipc-ops.h
+++ b/data/src/cfs-ipc-ops.h
@@ -43,4 +43,6 @@
 
 #define CFS_IPC_VERIFY_TOKEN 12
 
+#define CFS_IPC_GET_GUEST_CONFIG_PROPERTIES 13
+
 #endif
diff --git a/data/src/server.c b/data/src/server.c
index 549788a..80f838b 100644
--- a/data/src/server.c
+++ b/data/src/server.c
@@ -89,6 +89,13 @@ typedef struct {
 	char property[];
 } cfs_guest_config_propery_get_request_header_t;
 
+typedef struct {
+	struct qb_ipc_request_header req_header;
+	uint32_t vmid;
+	uint8_t num_props;
+	char props[]; /* list of \0 terminated properties */
+} cfs_guest_config_properties_get_request_header_t;
+
 typedef struct {
 	struct qb_ipc_request_header req_header;
 	char token[];
@@ -348,6 +355,62 @@ static int32_t s1_msg_process_fn(
 
 			result = cfs_create_guest_conf_property_msg(outbuf, memdb, rh->property, rh->vmid);
 		}
+	} else if (request_id == CFS_IPC_GET_GUEST_CONFIG_PROPERTIES) {
+
+		cfs_guest_config_properties_get_request_header_t *rh =
+			(cfs_guest_config_properties_get_request_header_t *) data;
+
+		size_t remaining = request_size - G_STRUCT_OFFSET(cfs_guest_config_properties_get_request_header_t, props);
+
+		result = 0;
+		if (rh->vmid < 100 && rh->vmid != 0) {
+			cfs_debug("vmid out of range %u", rh->vmid);
+			result = -EINVAL;
+		} else if (rh->vmid >= 100 && !vmlist_vm_exists(rh->vmid)) {
+			result = -ENOENT;
+		} else if (rh->num_props == 0) {
+			cfs_debug("num_props == 0");
+			result = -EINVAL;
+		} else if (remaining <= 1) {
+			cfs_debug("property length <= 1, %ld", remaining);
+			result = -EINVAL;
+		} else {
+			const char **properties = malloc(sizeof(char*) * rh->num_props);
+			char *current = (rh->props);
+			for (uint8_t i = 0; i < rh->num_props; i++) {
+			    size_t proplen = strnlen(current, remaining);
+			    if (proplen == 0) {
+				cfs_debug("property length 0");
+				result = -EINVAL;
+				break;
+			    }
+			    if (proplen == remaining || current[proplen] != '\0') {
+				cfs_debug("property not \\0 terminated");
+				result = -EINVAL;
+				break;
+			    }
+			    if (current[0] < 'a' || current[0] > 'z') {
+				cfs_debug("property does not start with [a-z]");
+				result = -EINVAL;
+				break;
+			    }
+			    properties[i] = current;
+			    remaining -= (proplen + 1);
+			    current += proplen + 1;
+			}
+
+			if (remaining != 0) {
+			    cfs_debug("leftover data after parsing %u properties", rh->num_props);
+			    result = -EINVAL;
+			}
+
+			if (result == 0) {
+			    cfs_debug("cfs_get_guest_config_properties: basic validity checked, do request");
+			    result = cfs_create_guest_conf_properties_msg(outbuf, memdb, properties, rh->num_props, rh->vmid);
+			}
+
+			free(properties);
+		}
 	} else if (request_id == CFS_IPC_VERIFY_TOKEN) {
 
 		cfs_verify_token_request_header_t *rh = (cfs_verify_token_request_header_t *) data;
diff --git a/data/src/status.c b/data/src/status.c
index 9bceaeb..2a54eaf 100644
--- a/data/src/status.c
+++ b/data/src/status.c
@@ -804,25 +804,63 @@ cfs_create_vmlist_msg(GString *str)
 	return 0;
 }
 
-// checks the conf for a line starting with '$prop:' and returns the value
-// afterwards, whitout initial whitespace(s), we only deal with the format
-// restricion imposed by our perl VM config parser, main reference is
+// checks if a config line starts with the given prop. if yes, writes a '\0'
+// at the end of the value, and returns the pointer where the value starts
+// note: line[line_end] needs to be guaranteed a null byte
+char *
+_get_property_value_from_line(char *line, size_t line_len, const char *prop, size_t prop_len)
+{
+	if (line_len <= prop_len + 1) return NULL;
+
+	if (line[prop_len] == ':' && memcmp(line, prop, prop_len) == 0) { // found
+		char *v_start = &line[prop_len + 1];
+		char *v_end = &line[line_len - 1];
+
+		// drop initial value whitespaces here already
+		while (v_start < v_end && *v_start && isspace(*v_start)) v_start++;
+
+		if (!*v_start) return NULL;
+
+		while (v_end > v_start && isspace(*v_end)) v_end--;
+		if (v_end < &line[line_len - 1]) {
+		    v_end[1] = '\0';
+		}
+
+		return v_start;
+	}
+
+	return NULL;
+}
+
+// checks the conf for lines starting with the given props and
+// writes the pointers into the correct positions into the 'found' array
+// afterwards, without initial whitespace(s), we only deal with the format
+// restriction imposed by our perl VM config parser, main reference is
 // PVE::QemuServer::parse_vm_config this allows to be very fast and still
 // relatively simple
-// main restrictions used for our advantage is the properties match reges:
+// main restrictions used for our advantage is the properties match regex:
 // ($line =~ m/^([a-z][a-z_]*\d*):\s*(.+?)\s*$/) from parse_vm_config
 // currently we only look at the current configuration in place, i.e., *no*
-// snapshort and *no* pending changes
-static char *
-_get_property_value(char *conf, int conf_size, const char *prop, int prop_len)
+// snapshot and *no* pending changes
+//
+// min..max is the char range of the first character of the given props,
+// so that we can return early when checking the line
+// note: conf must end with a newline
+void
+_get_property_values(char **found, char *conf, int conf_size, const char **props, uint8_t num_props, char min, char max)
 {
 	const char *const conf_end = conf + conf_size;
 	char *line = conf;
-	size_t remaining_size;
+	size_t remaining_size = conf_size;
+	uint8_t count = 0;
+
+	if (conf_size == 0) {
+	    return;
+	}
 
 	char *next_newline = memchr(conf, '\n', conf_size);
 	if (next_newline == NULL) {
-		return NULL; // valid property lines end with \n, but none in the config
+		return; // valid property lines end with \n, but none in the config
 	}
 	*next_newline = '\0';
 
@@ -830,41 +868,32 @@ _get_property_value(char *conf, int conf_size, const char *prop, int prop_len)
 		if (!line[0]) goto next;
 
 		// snapshot or pending section start, but nothing found yet -> not found
-		if (line[0] == '[') return NULL;
-		// properties start with /^[a-z]/, so continue early if not
-		if (line[0] < 'a' || line[0] > 'z') goto next;
-
-		int line_len = strlen(line);
-		if (line_len <= prop_len + 1) goto next;
-
-		if (line[prop_len] == ':' && memcmp(line, prop, prop_len) == 0) { // found
-			char *v_start = &line[prop_len + 1];
-
-			// drop initial value whitespaces here already
-			while (*v_start && isspace(*v_start)) v_start++;
-
-			if (!*v_start) return NULL;
-
-			char *v_end = &line[line_len - 1];
-			while (v_end > v_start && isspace(*v_end)) v_end--;
-			v_end[1] = '\0';
-
-			return v_start;
+		if (line[0] == '[') return;
+		// continue early if line does not begin with the min/max char of the properties
+		if (line[0] < min || line[0] > max) goto next;
+
+		size_t line_len = next_newline - line;
+		for (uint8_t i = 0; i < num_props; i++) {
+			char * value = _get_property_value_from_line(line, line_len, props[i], strlen(props[i]));
+			if (value != NULL) {
+				count += (found[i] != NULL) & 0x1; // count newly found lines
+				found[i] = value;
+			}
+		}
+		if (count == num_props) {
+			return; // found all
 		}
 next:
 		line = next_newline + 1;
 		remaining_size = conf_end - line;
-		if (remaining_size <= prop_len) {
-			return NULL;
-		}
 		next_newline = memchr(line, '\n', remaining_size);
 		if (next_newline == NULL) {
-			return NULL; // valid property lines end with \n, but none in the config
+			return; // valid property lines end with \n, but none in the config
 		}
 		*next_newline = '\0';
 	}
 
-	return NULL; // not found
+	return;
 }
 
 static void
@@ -883,24 +912,77 @@ _g_str_append_kv_jsonescaped(GString *str, const char *k, const char *v)
 }
 
 int
-cfs_create_guest_conf_property_msg(GString *str, memdb_t *memdb, const char *prop, uint32_t vmid)
+_print_found_properties(
+	GString *str,
+	gpointer conf,
+	int size,
+	const char **props,
+	uint8_t num_props,
+	uint32_t vmid,
+	char **values,
+	char min,
+	char max,
+	int first)
+{
+	_get_property_values(values, conf, size, props, num_props, min, max);
+
+	uint8_t found = 0;
+	for (uint8_t i = 0; i < num_props; i++) {
+		if (values[i] == NULL) {
+			continue;
+		}
+		if (found) {
+			g_string_append_c(str, ',');
+		} else {
+			if (!first) {
+				g_string_append_printf(str, ",\n");
+			} else {
+				first = 0;
+			}
+			g_string_append_printf(str, "\"%u\":{", vmid);
+			found = 1;
+		}
+		_g_str_append_kv_jsonescaped(str, props[i], values[i]);
+	}
+
+	if (found) {
+		g_string_append_c(str, '}');
+	}
+
+	return first;
+}
+
+int
+cfs_create_guest_conf_properties_msg(GString *str, memdb_t *memdb, const char **props, uint8_t num_props, uint32_t vmid)
 {
 	g_return_val_if_fail(cfs_status.vmlist != NULL, -EINVAL);
 	g_return_val_if_fail(str != NULL, -EINVAL);
 
-	int prop_len = strlen(prop);
-	int res = 0;
-	GString *path = NULL;
-
 	// Prelock &memdb->mutex in order to enable the usage of memdb_read_nolock
 	// to prevent Deadlocks as in #2553
 	g_mutex_lock (&memdb->mutex);
 	g_mutex_lock (&mutex);
 
-	g_string_printf(str,"{\n");
+	g_string_printf(str, "{\n");
 
 	GHashTable *ht = cfs_status.vmlist;
+
+	int res = 0;
+	GString *path = NULL;
 	gpointer tmp = NULL;
+	char **values = calloc(num_props, sizeof(char*));
+	char min = 'z', max = 'a';
+
+	for (uint8_t i = 0; i < num_props; i++) {
+		if (props[i][0] > max) {
+			max = props[i][0];
+		}
+
+		if (props[i][0] < min) {
+			min = props[i][0];
+		}
+	}
+
 	if (!g_hash_table_size(ht)) {
 		goto ret;
 	}
@@ -919,15 +1001,15 @@ cfs_create_guest_conf_property_msg(GString *str, memdb_t *memdb, const char *pro
 		// use memdb_read_nolock because lock is handled here
 		int size = memdb_read_nolock(memdb, path->str, &tmp);
 		if (tmp == NULL) goto err;
-		if (size <= prop_len) goto ret;
-
-		char *val = _get_property_value(tmp, size, prop, prop_len);
-		if (val == NULL) goto ret;
-
-		g_string_append_printf(str, "\"%u\":{", vmid);
-		_g_str_append_kv_jsonescaped(str, prop, val);
-		g_string_append_c(str, '}');
 
+		// conf needs to be newline terminated
+		if (((char *)tmp)[size - 1] != '\n') {
+			gpointer new = realloc(tmp, size + 1);
+			if (new == NULL) goto err;
+			tmp = new;
+			((char *)tmp)[size++] = '\n';
+		}
+		_print_found_properties(str, tmp, size, props, num_props, vmid, values, min, max, 1);
 	} else {
 		GHashTableIter iter;
 		g_hash_table_iter_init (&iter, ht);
@@ -943,21 +1025,24 @@ cfs_create_guest_conf_property_msg(GString *str, memdb_t *memdb, const char *pro
 			tmp = NULL;
 			// use memdb_read_nolock because lock is handled here
 			int size = memdb_read_nolock(memdb, path->str, &tmp);
-			if (tmp == NULL || size <= prop_len) continue;
-
-			char *val = _get_property_value(tmp, size, prop, prop_len);
-			if (val == NULL) continue;
-
-			if (!first) g_string_append_printf(str, ",\n");
-			else first = 0;
+			if (tmp == NULL) continue;
+
+			// conf needs to be newline terminated
+			if (((char *)tmp)[size - 1] != '\n') {
+			    gpointer new = realloc(tmp, size + 1);
+			    if (new == NULL) continue;
+			    tmp = new;
+			    ((char *)tmp)[size++] = '\n';
+			}
 
-			g_string_append_printf(str, "\"%u\":{", vminfo->vmid);
-			_g_str_append_kv_jsonescaped(str, prop, val);
-			g_string_append_c(str, '}');
+			memset(values, 0, sizeof(char*)*num_props); // reset array
+			first = _print_found_properties(str, tmp, size, props, num_props,
+					vminfo->vmid, values, min, max, first);
 		}
 	}
 ret:
 	g_free(tmp);
+	free(values);
 	if (path != NULL) {
 		g_string_free(path, TRUE);
 	}
@@ -973,6 +1058,12 @@ enoent:
 	goto ret;
 }
 
+int
+cfs_create_guest_conf_property_msg(GString *str, memdb_t *memdb, const char *prop, uint32_t vmid)
+{
+	return cfs_create_guest_conf_properties_msg(str, memdb, &prop, 1, vmid);
+}
+
 void
 record_memdb_change(const char *path)
 {
diff --git a/data/src/status.h b/data/src/status.h
index bbf0948..041cb34 100644
--- a/data/src/status.h
+++ b/data/src/status.h
@@ -163,4 +163,7 @@ cfs_create_memberlist_msg(
 int
 cfs_create_guest_conf_property_msg(GString *str, memdb_t *memdb, const char *prop, uint32_t vmid);
 
+int
+cfs_create_guest_conf_properties_msg(GString *str, memdb_t *memdb, const char **props, uint8_t num_props, uint32_t vmid);
+
 #endif /* _PVE_STATUS_H_ */
-- 
2.30.2