diff options
| -rw-r--r-- | namedev.c | 40 | ||||
| -rw-r--r-- | udev.8.in | 15 |
2 files changed, 55 insertions, 0 deletions
@@ -42,6 +42,7 @@ #include "logging.h" #include "namedev.h" #include "klibc_fixups.h" +#include "udevdb.h" static struct sysfs_attribute *find_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, char *attr); @@ -179,6 +180,37 @@ static int get_format_len(char **str) return -1; } +/** Finds the lowest positive N such that <name>N isn't present in + * $(udevroot) either as a file or a symlink. + * + * @param name Name to check for + * @return 0 if <name> didn't exist and N otherwise. + */ +static unsigned int find_free_number (struct udevice *udev, char *name) +{ + char temp[NAME_SIZE]; + char path[NAME_SIZE]; + struct udevice dev; + int result; + + /* have to sweep the database for each lookup */ + result = 0; + strncpy(temp, name, sizeof (temp)); + while (1) { + if (udevdb_get_dev_byname(temp, path, &dev) != 0) + goto found; + /* symlink might be stale if $(udevroot) isn't cleaned; check + * on major/minor to see if it's the same device + */ + if (dev.major == udev->major && dev.minor == udev->minor) + goto found; + snprintf (temp, sizeof(temp), "%s%d", name, ++result); + } + +found: + return result; +} + static void apply_format(struct udevice *udev, char *string, size_t maxsize, struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device) @@ -195,6 +227,7 @@ static void apply_format(struct udevice *udev, char *string, size_t maxsize, char *rest; int slen; struct sysfs_attribute *tmpattr; + unsigned int next_free_number; pos = string; while (1) { @@ -284,6 +317,13 @@ static void apply_format(struct udevice *udev, char *string, size_t maxsize, strfieldcatmax(string, "%", maxsize); pos++; break; + case 'e': + next_free_number = find_free_number(udev, string); + if (next_free_number > 0) { + snprintf(temp2, sizeof(temp2), "%d", next_free_number); + strfieldcatmax(string, temp2, maxsize); + } + break; default: dbg("unknown substitution type '%%%c'", c); break; @@ -272,6 +272,13 @@ all remaining parts of the result string are substituted: .BI %s{ filename } The content of a sysfs attribute. .TP +.B %e +If a device node already exists with the name, the smallest positive +decimal integer N is substituted such that the resulting name doesn't +match an existing device node. Otherwise nothing is substituted. This +can be used to create compatibility symlinks and enumerate devices of +the same type originating from different kernel subsystems. +.TP .B %% The '%' character itself. .P @@ -302,6 +309,14 @@ KERNEL="ttyUSB1", NAME="pda", SYMLINK="palmtop handheld" # multiple USB webcams with symlinks to be called webcam0, webcam1, ... BUS="usb", SYSFS{model}="XV3", NAME="video%n", SYMLINK="webcam%n" + +# grouping of optical drives from multiple kernel subsystems +KERNEL="sr*", NAME="%k", SYMLINK="cdrom%e" +KERNEL="scd*", NAME="%k", SYMLINK="cdrom%e" +KERNEL="pcd*", NAME="%k", SYMLINK="cdrom%e" +KERNEL="hd[a-z]", PROGRAM="/bin/cat /proc/ide/%k/media", RESULT="cdrom", + NAME="%k", SYMLINK="cdrom%e" + .fi .P The permissions and ownership of the created device file is read from |