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check the udevdb before assigning a new %e

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A second "add" event created a new enumeration with %e. Check the
udevdb first and if a matching name is already used.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
This commit is contained in:
Kay Sievers 2005-08-29 03:48:17 +02:00
parent a8586078fc
commit 2983db9745
1 changed files with 53 additions and 8 deletions
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61
udev_rules.c
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@ -267,16 +267,58 @@ static int import_parent_into_env(struct udevice *udev, struct sysfs_class_devic
return rc;
}
/* finds the lowest positive N such that <name>N isn't present in the udevdb
* if <name> doesn't exist, 0 is returned, N otherwise
*/
static int find_free_number(const char *name, const char *devpath)
static int match_name_and_get_number(const char *base, const char *devname)
{
size_t baselen;
char *endptr;
int num;
baselen = strlen(base);
if (strncmp(base, devname, baselen) != 0)
return -1;
if (devname[baselen] == '\0')
return 0;
if (!isdigit(devname[baselen]))
return -1;
num = strtoul(&devname[baselen], &endptr, 10);
if (endptr[0] != '\0')
return -1;
return num;
}
/* finds the lowest positive device number such that <name>N isn't present in the udevdb
* if <name> doesn't exist, 0 is returned, N otherwise */
static int find_free_number(const char *base, const char *devpath)
{
char db_devpath[PATH_SIZE];
char filename[PATH_SIZE];
struct udevice udev_db;
int num = 0;
strlcpy(filename, name, sizeof(filename));
/* check if the device already owns a matching name */
udev_init_device(&udev_db, NULL, NULL, NULL);
if (udev_db_get_device(&udev_db, devpath) == 0) {
struct name_entry *name_loop;
int devnum;
devnum = match_name_and_get_number(base, udev_db.name);
if (devnum >= 0) {
num = devnum;
dbg("device '%s', already has the node '%s' with num %u, use it", devpath, base, num);
goto out;
}
list_for_each_entry(name_loop, &udev_db.symlink_list, node) {
devnum = match_name_and_get_number(base, name_loop->name);
if (devnum >= 0) {
num = devnum;
dbg("device '%s', already has a symlink '%s' with num %u, use it", devpath, base, num);
goto out;
}
}
}
/* just search the database again and again until a free name is found */
strlcpy(filename, base, sizeof(filename));
while (1) {
dbg("look for existing node '%s'", filename);
if (udev_db_lookup_name(filename, db_devpath, sizeof(db_devpath)) != 0) {
@ -290,10 +332,12 @@ static int find_free_number(const char *name, const char *devpath)
num = -1;
break;
}
snprintf(filename, sizeof(filename), "%s%d", name, num);
snprintf(filename, sizeof(filename), "%s%d", base, num);
filename[sizeof(filename)-1] = '\0';
}
out:
udev_cleanup_device(&udev_db);
return num;
}
@ -345,12 +389,12 @@ static int wait_for_sysfs(struct udevice *udev, const char *file, int timeout)
while (--loop) {
if (stat(filename, &stats) == 0) {
dbg("file appeared after %i loops", (timeout * WAIT_LOOP_PER_SECOND) - loop-1);
info("file appeared after %i loops", (timeout * WAIT_LOOP_PER_SECOND) - loop-1);
return 0;
}
usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
}
dbg("waiting for '%s' failed", filename);
info("waiting for '%s' failed", filename);
return -1;
}
@ -669,6 +713,7 @@ static int match_key(const char *key_name, struct udev_rule *rule, struct key *k
return -1;
}
/* match a single rule against a given device and possibly its parent devices */
static int match_rule(struct udevice *udev, struct udev_rule *rule,
struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
{