vfs_mount(9) [debian man page]

VFS_MOUNT(9)						   BSD Kernel Developer's Manual					      VFS_MOUNT(9)

NAME

     vfs_mount -- generic file system mount function

SYNOPSIS

     #include <sys/param.h>
     #include <sys/mount.h>

     int
     vfs_mount(struct thread *td, const char *fstype, char *fspath, int fsflags, void *fsdata);

DESCRIPTION

     The vfs_mount() function handles the generic portion of mounting a file system, and calls the file system specific mount function after veri-
     fying its parameters and setting up the structures expected by the underlying mount code.

     vfs_mount() is called directly by the mount(2) system call.

     Its arguments are:

     td       The thread responsible for this call.

     fstype   The type of file system being mounted.

     fspath   The path to the mount point of the file system.

     fsflags  Flags controlling the mount.  See mount(2) for details.

	      MNT_EXPORTED, MNT_NOSUID, MNT_UPDATE, MNT_RELOAD, MNT_FORCE, MNT_ASYNC, MNT_SYNCHRONOUS, MNT_UNION, MNT_NOATIME, MNT_SNAPSHOT,
	      MNT_NOCLUSTERR, MNT_NOCLUSTERW, MNT_IGNORE, MNT_UNION, MNT_NOSYMFOLLOW

     fsdata   File system specific data structure.  It is in userspace when passed to vfs_mount() and is left untouched when passed to file sys-
	      tem's mount().

RETURN VALUES

     A 0 value is returned on success.

ERRORS

     [ENAMETOOLONG]	The fs type or the mount point path is too long or any individual path component is too long.

     [EPERM]		Permission denied.  There are a number of reason this can occur ranging from the user not having permission to mount a
			file system to the securelevel being to high to load the fstype module.

     [EINVAL]		Invalid operation (ex: trying to update a non mount-point).

     [ENOENT]		The mount point does not exist (from namei()).

     [ELOOP]		The mount point is a muddle of links (from namei()).

     [EOPNOTSUPP]	The operation is not supported (ex: reloading a r/w file system).

     [EBUSY]		The mount point is busy or is not really a mount point (on update).

     [ENOTDIR]		The mount point is not a directory.

     [ENODEV]		The kernel linker was unable to load the specified fstype or was unable to find the specified fstype module.

     Other errors can be returned by the file system's mount() and you should check the specific file system for details.  Also this call relies
     on a large number of other kernel services whose errors it returns so this list may not be exhaustive.

SEE ALSO

     mount(2), mount(8)

     vfs.usermount

AUTHORS

     This manual page was written by Chad David <davidc@acns.ab.ca>.

BSD
								 November 26, 2004							       BSD

VFSCONF(9)						   BSD Kernel Developer's Manual						VFSCONF(9)

NAME

     vfsconf -- vfs configuration information

SYNOPSIS

     #include <sys/param.h>
     #include <sys/mount.h>

     int
     vfs_register(struct vfsconf *vfc);

     int
     vfs_unregister(struct vfsconf *vfc);

     int
     vfs_modevent(module_t mod, int type, void *data);

DESCRIPTION

     Each file system type known to the kernel has a vfsconf structure that contains the information required to create a new mount of that file
     systems type.

     struct vfsconf {
	     struct  vfsops *vfc_vfsops;     /* file system operations vector */
	     char    vfc_name[MFSNAMELEN];   /* file system type name */
	     int     vfc_typenum;	     /* historic file system type number */
	     int     vfc_refcount;	     /* number mounted of this type */
	     int     vfc_flags; 	     /* permanent flags */
	     struct  vfsconf *vfc_next;      /* next in list */
     };

     When a new file system is mounted, vfs_mount(9) does a lookup of the vfsconf structure by its name, and if it is not already registered,
     attempts to load a kernel module for it.  The file system operations for the new mount point are taken from vfc_vfsops, and mnt_vfc in the
     mount structure is made to point directly at the vfsconf structure for the file system type.  The file system type number is taken from
     vfc_typenum which was assigned in vfs_register(), and the mount flags are taken from a mask of vfc_flags.	Each time a file system of a given
     type is mounted, vfc_refcount is incremented.

     vfs_register() takes a new vfsconf structure and adds it to the list of existing file systems.  If the type has not already been registered,
     it is initialized by calling the vfs_init() function in the file system operations vector.  vfs_register() also updates the oid's of any
     sysctl nodes for this file system type to be the same as the newly assigned type number.

     vfs_unregister() unlinks vfc from the list of registered file system types if there are currently no mounted instances.  If the vfs_uninit()
     function in the file systems initialization vector is defined, it is called.

     vfs_modevent() is registered by VFS_SET() to handle the loading and unloading of file system kernel modules.  In the case of MOD_LOAD,
     vfs_register() is called.	In the case of MOD_UNLOAD, vfs_unregister() is called.

RETURN VALUES

     vfs_register() returns 0 if successful; otherwise, EEXIST is returned indicating that the file system type has already been registered.

     vfs_unregister() returns 0 if successful.	If no vfsconf entry can be found matching the name in vfc, EINVAL is returned.	If the reference
     count of mounted instances of the file system type is not zero, EBUSY is returned.  If vfs_uninit() is called, any errors it returns will be
     returned by vfs_unregister().

     vfs_modevent() returns the result of the call to vfs_register() or vfs_unregister(), whatever the case.

SEE ALSO

     vfs_mount(9), vfs_rootmountalloc(9), VFS_SET(9)

AUTHORS

     This manual page was written by Chad David <davidc@acns.ab.ca>.

BSD
								 November 21, 2001							       BSD