device_nodes(3K)               DG/UX R4.11MU05              device_nodes(3K)


NAME
       device_nodes:  fs_submit_dev_pathname_request - create or delete
       device nodes

SYNOPSIS
       #include "/usr/src/uts/aviion/ii/i_fs.h"

       void          fs_submit_dev_pathname_request (
           fs_dev_request_operation_enum_type      operation,    /*READ_ONLY*/
           ...
                                                    )

DESCRIPTION
       This routine is used by device drivers to submit a request to create
       or delete a /dev entry.  If the root file system is already mounted,
       the request will be processed immediately.  Otherwise, the request is
       added to a queue for processing as soon as the root file system is
       mounted.

       The operation parameter is an enumeration value describing the opera­
       tion to be performed: Fs_Dev_Request_Operation_Create to create a de­
       vice node, or Fs_Dev_Request_Operation_Delete to delete one.

       There are one or more variadic function arguments; these are pointers
       to pathname component structures that together describe the device
       node to be created or deleted.  The first argument describes the
       first component of the node's pathname (e.g., the dev in
       /dev/dsk/root); the second argument describes the second pathname
       component; etc.  The argument list must be terminated by the pointer
       value FS_DEV_PATHNAME_NULL_COMPONENT.  Each pathname component struc­
       ture looks like:

       typedef struct {
           char_type                               name[MAXNAMELEN];
           df_file_mode_type                       mode_bits;
           uint32_type                             user_id;
           uint32_type                             group_id;
           io_device_number_type                   device;
           }
           fs_dev_pathname_component_type;

       The fields in this structure are relevant only for
       Fs_Dev_Request_Operation_Create operations, except as noted below.
       The fields are:

           name      The filename of the component in the pathname of the
                     device node that is being created or deleted.  For ex­
                     ample, the filename of the first component of a request
                     to create or delete /dev/dsk/root would be "dev", while
                     the filename of the third component of that request
                     would be "root".

           mode_bits The initial mode bits of the pathname component being
                     created, including both access permissions (read,
                     write, execute, etc.) and file type information (direc­
                     tory vs. character-special file vs. block-special
                     file).

           user_id   The user ID to be assigned to pathname component being
                     created.

           group_id  The group ID to be assigned to pathname component being
                     created.

           device    The device number of the node being created.  This
                     field is only valid if the component being created is a
                     block-special or character-special file.

           The attributes (mode bits, user ID and group ID) of intermediate
           directory components are relevant only during
           Fs_Dev_Request_Operation_Create operations, and then only for in­
           termediate directories that don't already exist.  Once created,
           such directories' attributes will not be changed by any subse­
           quent create requests.  During Fs_Dev_Request_Operation_Delete
           operations, only the device node component of the request is
           deleted; all intermediate directories are unaffected.

           For convenience, a number of predefined pathname component struc­
           tures have been created in the FS subsystem.  They include
           fs_dev_dev_pathname_component (used to specify /dev itself),
           fs_dev_pdsk_pathname_component (used to specify the pdsk subdi­
           rectory of /dev), and many other structures with names of the
           form fs_dev_directory_pathname_component.

DIAGNOSTICS
       Requests to create device nodes that already exist will result in er­
       ror messages to the system console.

EXAMPLES
       The following example creates a character-special device node named
       /dev/net/device_node_name with device_number as the node's device
       number:

       char_ptr_type                     device_node_name;
       io_device_number_type             device_number;
       fs_dev_pathname_component_type    node_component;

       node_component.mode_bits = S_IFCHR | S_IRUSR | S_IWUSR;
       node_component.user_id = FS_STANDARD_DEVICE_USER_ID;
       node_component.group_id = FS_STANDARD_DEVICE_GROUP_ID;
       node_component.device = device_number;
       misc_format_line (node_component.name, usizeof (node_component.name),
                                               "%s", device_node_name);

       fs_submit_dev_pathname_request (Fs_Dev_Request_Operation_Create,
                                       &fs_dev_dev_pathname_component,
                                       &fs_dev_net_pathname_component,
                                       &node_component,
                                       FS_DEV_PATHNAME_NULL_COMPONENT);

SEE ALSO
       device_configuration(3K).
       Programming in the DG/UX Kernel Environment.


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