[PATCH] add %P modifier to query the node name of the parent device

Events for partition devies may want to read the main block device
name to compose it's own name or read a disklabel from the main device.

SUBSYSTEM="block", KERNEL="*[1-9]", NAME="%P-p%n"
will append the partition number to the name of the main block device.

diff --git a/namedev.c b/namedev.c
index 332e2d57d80f9a773ef0579ce2eb8f0c723c0dad..90d988311e2bbf3af044271390d5becb80e51fa8 100644 (file)
--- a/namedev.c
+++ b/namedev.c
@@ -183,6 +183,7 @@ static void apply_format(struct udevice *udev, char *string, size_t maxsize,
        int slen;
        struct sysfs_attribute *tmpattr;
        unsigned int next_free_number;
+       struct sysfs_class_device *class_dev_parent;
 
        pos = string;
        while (1) {
@@ -296,6 +297,22 @@ static void apply_format(struct udevice *udev, char *string, size_t maxsize,
                                strfieldcatmax(string, temp2, maxsize);
                        }
                        break;
+               case 'P':
+                       class_dev_parent = sysfs_get_classdev_parent(class_dev);
+                       if (class_dev_parent != NULL) {
+                               struct udevice udev_parent;
+
+                               dbg("found parent '%s', get the node name", class_dev_parent->path);
+                               memset(&udev_parent, 0x00, sizeof(struct udevice));
+                               /* lookup the name in the udev_db with the DEVPATH of the parent */
+                               strfieldcpy(udev_parent.devpath, &class_dev_parent->path[strlen(sysfs_path)]);
+                               if (udev_db_get_device(&udev_parent) == 0) {
+                                       strfieldcatmax(string, udev_parent.name, maxsize);
+                                       dbg("substitute parent node name'%s'", udev_parent.name);
+                               } else
+                                       dbg("parent not found in database");
+                       }
+                       break;
                case 'N':
                        if (udev->tmp_node[0] == '\0') {
                                dbg("create temporary device node for callout");
@@ -305,6 +322,10 @@ static void apply_format(struct udevice *udev, char *string, size_t maxsize,
                        strfieldcatmax(string, udev->tmp_node, maxsize);
                        dbg("substitute temporary device node name '%s'", udev->tmp_node);
                        break;
+               case 'r':
+                       strfieldcatmax(string, udev_root, maxsize);
+                       dbg("substitute udev_root '%s'", udev_root);
+                       break;
                default:
                        dbg("unknown substitution type '%%%c'", c);
                        break;

diff --git a/test/udev-test.pl b/test/udev-test.pl
index fa1e4affc6d4dbb90f7432a991394699dd7515ea..5a519ef13b40145e57e6839f4f788c05c809e3a6 100644 (file)
--- a/test/udev-test.pl
+++ b/test/udev-test.pl
@@ -968,7 +968,7 @@ KERNEL="sda", NAME="cdrom%e"
 EOF
        },
        {
-               desc            => "enumeration char test sequence (1/5 keep)",
+               desc            => "enumeration char test sequence 1/5 (keep)",
                subsys          => "block",
                devpath         => "/block/sda",
                exp_name        => "cdrom",
@@ -1084,6 +1084,36 @@ EOF
                exp_name        => "sda",
                conf            => <<EOF
 BUS="scsi", KERNEL="sda", PROGRAM="/bin/echo %p", RESULT="/block/sda" NAME="%k"
+EOF
+       },
+       {
+               desc            => "parent node name substitution test sequence 1/2 (keep)",
+               subsys          => "block",
+               devpath         => "/block/sda",
+               exp_name        => "main_device",
+               option          => "keep",
+               conf            => <<EOF
+BUS="scsi", KERNEL="sda", NAME="main_device"
+EOF
+       },
+       {
+               desc            => "parent node name substitution test sequence 2/2 (clean)",
+               subsys          => "block",
+               devpath         => "/block/sda/sda1",
+               exp_name        => "main_device-part-1",
+               option          => "clean",
+               conf            => <<EOF
+BUS="scsi", KERNEL="sda1", NAME="%P-part-1"
+EOF
+       },
+       {
+               desc            => "udev_root substitution",
+               subsys          => "block",
+               devpath         => "/block/sda/sda1",
+               exp_name        => "start-udev-root-end",
+               option          => "clean",
+               conf            => <<EOF
+BUS="scsi", KERNEL="sda1", NAME="start-%r-end"
 EOF
        },
 );

diff --git a/udev.8.in b/udev.8.in
index 51c55bc5a6adc83cfc7ea609f8ce7ab2a284c2a7..3fb4bdb8da9e0ff08ad813d9d7ecaa3c8150f2cc 100644 (file)
--- a/udev.8.in
+++ b/udev.8.in
@@ -218,6 +218,9 @@ all remaining parts of the result string are substituted:
 The name of a created temporary device node to provide access to the
 device from a external program.
 .TP
+.B %P
+The node name of the parent device.
+.TP
 .BI %s{ filename }
 The content of a sysfs attribute.
 .TP