From 1bb734a44952a51285057409ba7b1c3e7a162cea Mon Sep 17 00:00:00 2001
From: Michal Sekletar <msekleta@redhat.com>
Date: Thu, 2 Aug 2018 13:16:49 +0200
Subject: [PATCH] Revert "udev: remove WAIT_FOR key"
This reverts commit f2b8052fb648b788936dd3e85be6a9aca90fbb2f.
Resolves: #1523213
---
man/udev.xml | 9 +++++++
src/udev/udev-rules.c | 50 +++++++++++++++++++++++++++++++++++++++
test/rule-syntax-check.py | 2 +-
3 files changed, 60 insertions(+), 1 deletion(-)
diff --git a/man/udev.xml b/man/udev.xml
index 15e6d8eae..bdf901a8f 100644
--- a/man/udev.xml
+++ b/man/udev.xml
@@ -515,6 +515,15 @@
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><varname>WAIT_FOR</varname></term>
+ <listitem>
+ <para>Wait for a file to become available or until a timeout of
+ 10 seconds expires. The path is relative to the sysfs device;
+ if no path is specified, this waits for an attribute to appear.</para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><varname>OPTIONS</varname></term>
<listitem>
diff --git a/src/udev/udev-rules.c b/src/udev/udev-rules.c
index f02939588..58af863f3 100644
--- a/src/udev/udev-rules.c
+++ b/src/udev/udev-rules.c
@@ -676,6 +676,41 @@ static int import_parent_into_properties(struct udev_device *dev, const char *fi
return 0;
}
+#define WAIT_LOOP_PER_SECOND 50
+static int wait_for_file(struct udev_device *dev, const char *file, int timeout) {
+ char filepath[UTIL_PATH_SIZE];
+ char devicepath[UTIL_PATH_SIZE];
+ struct stat stats;
+ int loop = timeout * WAIT_LOOP_PER_SECOND;
+
+ /* a relative path is a device attribute */
+ devicepath[0] = '\0';
+ if (file[0] != '/') {
+ strscpyl(devicepath, sizeof(devicepath), udev_device_get_syspath(dev), NULL);
+ strscpyl(filepath, sizeof(filepath), devicepath, "/", file, NULL);
+ file = filepath;
+ }
+
+ while (--loop) {
+ const struct timespec duration = { 0, 1000 * 1000 * 1000 / WAIT_LOOP_PER_SECOND };
+
+ /* lookup file */
+ if (stat(file, &stats) == 0) {
+ log_debug("file '%s' appeared after %i loops", file, (timeout * WAIT_LOOP_PER_SECOND) - loop-1);
+ return 0;
+ }
+ /* make sure, the device did not disappear in the meantime */
+ if (devicepath[0] != '\0' && stat(devicepath, &stats) != 0) {
+ log_debug("device disappeared while waiting for '%s'", file);
+ return -2;
+ }
+ log_debug("wait for '%s' for %i mseconds", file, 1000 / WAIT_LOOP_PER_SECOND);
+ nanosleep(&duration, NULL);
+ }
+ log_debug("waiting for '%s' failed", file);
+ return -1;
+}
+
static void attr_subst_subdir(char *attr, size_t len) {
const char *pos, *tail, *path;
_cleanup_closedir_ DIR *dir = NULL;
@@ -1284,7 +1319,12 @@ static void add_rule(struct udev_rules *rules, char *line,
rule_add_key(&rule_tmp, TK_A_RUN_PROGRAM, op, value, &cmd);
} else
LOG_RULE_ERROR("ignoring unknown %s{} type '%s'", "RUN", attr);
+ } else if (streq(key, "WAIT_FOR") || streq(key, "WAIT_FOR_SYSFS")) {
+ if (op == OP_REMOVE)
+ LOG_AND_RETURN("invalid %s operation", key);
+ rule_add_key(&rule_tmp, TK_M_WAITFOR, 0, value, NULL);
+ continue;
} else if (streq(key, "LABEL")) {
if (op == OP_REMOVE)
LOG_AND_RETURN("invalid %s operation", key);
@@ -1838,6 +1878,16 @@ void udev_rules_apply_to_event(struct udev_rules *rules,
if (match_key(rules, cur, udev_device_get_driver(event->dev)) != 0)
goto nomatch;
break;
+ case TK_M_WAITFOR: {
+ char filename[UTIL_PATH_SIZE];
+ int found;
+
+ udev_event_apply_format(event, rules_str(rules, cur->key.value_off), filename, sizeof(filename), false);
+ found = (wait_for_file(event->dev, filename, 10) == 0);
+ if (!found && (cur->key.op != OP_NOMATCH))
+ goto nomatch;
+ break;
+ }
case TK_M_ATTR:
if (match_attr(rules, event->dev, event, cur) != 0)
goto nomatch;
diff --git a/test/rule-syntax-check.py b/test/rule-syntax-check.py
index dfb06d9ed..706d93632 100755
--- a/test/rule-syntax-check.py
+++ b/test/rule-syntax-check.py
@@ -18,7 +18,7 @@ if not rules_files:
quoted_string_re = r'"(?:[^\\"]|\\.)*"'
no_args_tests = re.compile(r'(ACTION|DEVPATH|KERNELS?|NAME|SYMLINK|SUBSYSTEMS?|DRIVERS?|TAG|PROGRAM|RESULT|TEST)\s*(?:=|!)=\s*' + quoted_string_re + '$')
args_tests = re.compile(r'(ATTRS?|ENV|TEST){([a-zA-Z0-9/_.*%-]+)}\s*(?:=|!)=\s*' + quoted_string_re + '$')
-no_args_assign = re.compile(r'(NAME|SYMLINK|OWNER|GROUP|MODE|TAG|RUN|LABEL|GOTO|OPTIONS|IMPORT)\s*(?:\+=|:=|=)\s*' + quoted_string_re + '$')
+no_args_assign = re.compile(r'(NAME|SYMLINK|OWNER|GROUP|MODE|TAG|RUN|LABEL|GOTO|WAIT_FOR|OPTIONS|IMPORT)\s*(?:\+=|:=|=)\s*' + quoted_string_re + '$')
args_assign = re.compile(r'(ATTR|ENV|IMPORT|RUN){([a-zA-Z0-9/_.*%-]+)}\s*(=|\+=)\s*' + quoted_string_re + '$')
# Find comma-separated groups, but allow commas that are inside quoted strings.
# Using quoted_string_re + '?' so that strings missing the last double quote