include/sys/vfs.h

	vfs.h revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 1988 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * File system identifier. Should be unique (at least per machine).
 */

#ifndef _sys_vfs_h
#define _sys_vfs_h

typedef struct {
    long val[2];            /* file system id type */
} fsid_t;

/*
 * File identifier. Should be unique per filesystem on a single machine.
 */
#define MAXFIDSZ    16
#define freefid(fidp) \
    kmem_free((caddr_t)(fidp), sizeof (struct fid) - MAXFIDSZ + (fidp)->fid_len)

struct fid {
    u_short     fid_len;        /* length of data in bytes */
    char        fid_data[MAXFIDSZ]; /* data (variable length) */
};

/*
 * Structure per mounted file system.
 * Each mounted file system has an array of
 * operations and an instance record.
 * The file systems are put on a singly linked list.
 * If vfs_stats is non-NULL statistics are gathered, see vfs_stat.h
 */
struct vfs {
    struct vfs  *vfs_next;      /* next vfs in vfs list */
    struct vfsops   *vfs_op;        /* operations on vfs */
    struct vnode    *vfs_vnodecovered;  /* vnode we mounted on */
    int     vfs_flag;       /* flags */
    int     vfs_bsize;      /* native block size */
    fsid_t      vfs_fsid;       /* file system id */
    caddr_t     vfs_stats;      /* filesystem statistics */
    caddr_t     vfs_data;       /* private data */
};

/*
 * vfs flags.
 * VFS_MLOCK lock the vfs so that name lookup cannot proceed past the vfs.
 * This keeps the subtree stable during mounts and unmounts.
 */
#define VFS_RDONLY  0x01        /* read only vfs */
#define VFS_MLOCK   0x02        /* lock vfs so that subtree is stable */
#define VFS_MWAIT   0x04        /* someone is waiting for lock */
#define VFS_NOSUID  0x08        /* turn off set-uid on exec */
#define VFS_GRPID   0x10        /* Old BSD group-id on create */
#define VFS_NOSUB   0x20        /* No mounts allowed beneath this fs */
#define VFS_REMOUNT 0x40        /* modify mount otions only */
#define VFS_MULTI   0x80        /* Do multi-component lookup on files */

/*
 * Operations supported on virtual file system.
 */
struct vfsops {
    int (*vfs_mount)();     /* mount file system */
    int (*vfs_unmount)();   /* unmount file system */
    int (*vfs_root)();      /* get root vnode */
    int (*vfs_statfs)();    /* get fs statistics */
    int (*vfs_sync)();      /* flush fs buffers */
    int (*vfs_vget)();      /* get vnode from fid */
    int (*vfs_mountroot)(); /* mount the root filesystem */
    int (*vfs_swapvp)();    /* return vnode for swap */
};

#define VFS_MOUNT(VFSP, PATH, DATA) \
                 (*(VFSP)->vfs_op->vfs_mount)(VFSP, PATH, DATA)
#define VFS_UNMOUNT(VFSP)    (*(VFSP)->vfs_op->vfs_unmount)(VFSP)
#define VFS_ROOT(VFSP, VPP)  (*(VFSP)->vfs_op->vfs_root)(VFSP,VPP)
#define VFS_STATFS(VFSP, SBP)    (*(VFSP)->vfs_op->vfs_statfs)(VFSP,SBP)
#define VFS_SYNC(VFSP)       (*(VFSP)->vfs_op->vfs_sync)(VFSP)
#define VFS_VGET(VFSP, VPP, FIDP) (*(VFSP)->vfs_op->vfs_vget)(VFSP, VPP, FIDP)
#define VFS_MOUNTROOT(VFSP, VPP, NM) \
                 (*(VFSP)->vfs_op->vfs_mountroot)(VFSP, VPP, NM)
#define VFS_SWAPVP(VFSP, VPP, NM) (*(VFSP)->vfs_op->vfs_swapvp)(VFSP, VPP, NM)

/*
 * file system statistics
 */
struct statfs {
    long f_type;            /* type of info, zero for now */
    long f_bsize;           /* fundamental file system block size */
    long f_blocks;          /* total blocks in file system */
    long f_bfree;           /* free block in fs */
    long f_bavail;          /* free blocks avail to non-superuser */
    long f_files;           /* total file nodes in file system */
    long f_ffree;           /* free file nodes in fs */
    fsid_t f_fsid;          /* file system id */
    long f_spare[7];        /* spare for later */
};

#ifdef KERNEL
/*
 * Filesystem type switch table
 */
struct vfssw {
    char        *vsw_name;  /* type name string */
    struct vfsops   *vsw_ops;   /* filesystem operations vector */
};

/*
 * public operations
 */
extern void vfs_mountroot();    /* mount the root */
extern int  vfs_add();      /* add a new vfs to mounted vfs list */
extern void vfs_remove();       /* remove a vfs from mounted vfs list */
extern int  vfs_lock();     /* lock a vfs */
extern void vfs_unlock();       /* unlock a vfs */
extern struct vfs *getvfs();        /* return vfs given fsid */
extern struct vfssw *getfstype();   /* find default filesystem type */
extern int vfs_getmajor();      /* get major device # for an fs type */
extern void vfs_putmajor();     /* free major device # for an fs type */
extern int vfs_getnum();        /* get device # for an fs type */
extern void vfs_putnum();       /* release device # for an fs type */

#define VFS_INIT(VFSP, OP, DATA)    { \
    (VFSP)->vfs_next = (struct vfs *)0; \
    (VFSP)->vfs_op = (OP); \
    (VFSP)->vfs_flag = 0; \
    (VFSP)->vfs_stats = NULL; \
    (VFSP)->vfs_data = (DATA); \
}

/*
 * globals
 */
extern struct vfs *rootvfs;     /* ptr to root vfs structure */
extern struct vfssw vfssw[];        /* table of filesystem types */
extern struct vfssw *vfsNVFS;       /* vfs switch table end marker */
#endif

#endif /*!_sys_vfs_h*/