VFSSUBR(9)

NAME
vfssubr, vfs_getnewfsid, vfs_getvfs, vfs_export, vfs_showexport, vfs_export_lookup, vfs_setpublicfs, vfs_mountedon, vfs_mountroot, vfs_unmountall, vfs_busy, vfs_unbusy, vfs_rootmountalloc, vfs_shutdown, vfs_attach, vfs_detach, vfs_reinit, vfs_getopsbyname, vfs_write_suspend, vfs_write_resume - high-level interface to kernel file system interface

SYNOPSIS
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/vnode.h>
void
vfs_getnewfsid(struct mount *mp);
struct mount *
vfs_getvfs(fsid_t *fsid);
int
vfs_export_lookup(struct mount *mp, struct netexport *nep, struct export_args *argp);
int
vfs_setpublicfs(struct mount *mp, struct netexport *nep, struct export_args *argp);
int
vfs_mountedon(struct vnode *vp);
int
vfs_mountroot(void);
void
vfs_unmountall(struct lwp *l);
int
vfs_busy(struct mount *mp, int flags, struct simplelock *interlkp);
void
vfs_unbusy(struct mount *mp);
int
vfs_rootmountalloc(char *fstypename, char *devname, struct mount **mpp);
void
vfs_shutdown(void);
int
vfs_attach(struct vfsops *vfs);
int
vfs_detach(struct vfsops *vfs);
void
vfs_reinit(void);
struct vfsops *
vfs_getopsbyname(const char *name);
int
vfs_write_suspend(struct mount *mp, int slpflag, int slptimeo);
void
vfs_write_resume(struct mount *mp);

DESCRIPTION
The high-level functions described in this page are the interface to the kernel file system interface (VFS).

FUNCTIONS

vfs_getnewfsid(mp)
    Get a new unique file system id type for the file system specified by the mount structure mp. The file system id type is stored in mp-mnt_stat.f_fsidx.

vfs_getvfs(fsid)
    Lookup a mount point with the file system identifier fsid.

vfs_export_lookup(mp, nep, argp)
    Check client permission on the exportable file system specified by the mount structure mp. The argument nam is the address of the networked client. This function is used by file system type specific functions to verify that the client can access the file system.

vfs_setpublicfs(mp, nep, argp)
    Set the publicly exported file system specified by the mount structure mp.

vfs_mountedon(vp)
    Check to see if a file system is mounted on a block device specified by the vnode vp.

vfs_mountroot(void)
    Mount the root file system.

vfs_unmountall(l)
    Unmount all file systems.

vfs_busy(mp, flags, interlkp)
    Mark the mount point specified by mp as busy. This function is used to synchronize access and to delay unmounting. The interlock specified by argument interlkp is not released on failure.

vfs_unbusy(mp)
    Free the busy file system specified by the mount structure mp.

vfs_rootmountalloc(fstypename, devname, mpp)
    Lookup a file system type specified by the name fstypename and if found allocate and initialise a mount structure for it. The allocated mount structure is returned in the address specified by mpp. The device the root file system was mounted from is specified by the argument devname and is recorded in the new mount structure.

vfs_shutdown()
    Sync and unmount all file systems before shutting down. Invoked by cpu_reboot(9).

vfs_attach(vfs)
    Establish file system vfs and initialise it.

vfs_detach(vfs)
    Remove file system vfs from the kernel.

vfs_reinit(void)
    Reinitialises all file systems within the kernel through file system-specific vfs operation (see vfsops(9)).

vfs_getopsbyname(name)
    Given a file system name specified by name, look up the vfs operations for that file system (see vfsops(9)), or return NULL if file system isn't present in the kernel.

vfs_write_suspend(mp, slpflag, slptimeo)
    Request a mounted file system to suspend write operations. All new write operations to the file system are stopped. After all write operations in progress have completed, the file system is synced to disk and the function returns. If the file system is currently suspended the sleep(9) flag and timeout are specified by the arguments slpflag and slptimeo respectively. If slptimeo is less than zero EWOULDBLOCK is returned. If the operation is successful, zero is returned, otherwise an appropriate error code is returned.

vfs_write_resume(mp)
    Request a mounted file system to resume write operations.

CODE REFERENCES
This section describes places within the NetBSD source tree where actual code implementing or using the vfs operations can be found. All pathnames are relative to /usr/src.

The vfs interface functions are implemented within the files sys/kern/vfs_subr.c and sys/kern/vfs_init.c.

SEE ALSO
intro(9), namei(9), vfs(9), vfsops(9), vnode(9), vnodeops(9)