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AIX Version 4.3 Kernel and Subsystems Technical Reference, Volume 1

gfsadd Kernel Service


Adds a file system type to the gfs table.


#include <sys/types.h>
#include <sys/errno.h>

int gfsadd ( gfsno, gfsp)
int gfsno;
struct gfs *gfsp;


gfsno Specifies the file system number. This small integer value is either defined in the /usr/include/sys/vmount.h file or a user-defined number of the same order.
gfsp Points to the file system description structure.


The gfsadd kernel service is used during configuration of a file system. The configuration routine for a file system invokes the gfsadd kernel service with a gfs structure. This structure describes the file system type.

The gfs structure type is defined in the /usr/include/sys/gfs.h file. The gfs structure must have the following fields filled in:

gfs_type Specifies the integer type value. The predefined types are listed in the /usr/include/sys/vmount.h file.
gfs_name Specifies the character string name of the file system. The maximum length of this field is 16 bytes. Shorter names must be null-padded.
gfs_flags Specifies the flags that define the capabilities of the file system. The following flag values are defined:

GFS_SYS5DIR File system that uses the System V-type directory structure.
GFS_REMOTE File system is remote (ie. NFS).
GFS_FUMNT File system supports forced unmount.
GFS_NOUMASK File system applies umask when creating new objects.
GFS_VERSION4 File system supports AIX Version 4 V-node interface.
GFS_VERSION42 File system supports AIX Version 4.2 V-node interface. (new vnode op: vn_seek)
GFS_VERSION421 File system supports AIX Version 4.2.1 V-node interface.(new vnode ops: vn_sync_range, vn_create_attr, vn_finfo, vn_map_lloff, vn_readdir_eofp, vn_rdwr_attr))
GFS_VERSION43 File system supports AIX Version 4.3 V-node interface. (new file flag for vn_sync_range:FMSYNC)
gfs_ops Specifies the array of pointers to vfs operation implementations.
gn_ops Specifies the array of pointers to v-node operation implementations.

The file system description structure can also specify:

gfs_init Points to an initialization routine to be called by the gfsadd kernel service. This field must be null if no initialization routine is to be called.
gfs_data Points to file system private data.

Execution Environment

The gfsadd kernel service can be called from the process environment only.

Return Values

0 Indicates successful completion.
EBUSY Indicates that the file system type has already been installed.
EINVAL Indicates that the gfsno value is larger than the system-defined maximum. The system-defined maximum is indicated in the /usr/include/sys/vmount.h file.

Implementation Specifics

The gfsadd kernel service is part of Base Operating System (BOS) Runtime.

Related Information

The gfsdel kernel service.

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