/*
 * (MPSAFE)
 *
 * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Alex Hornung <ahornung@gmail.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/namecache.h>
#include <sys/vnode.h>
#include <sys/jail.h>
#include <sys/lock.h>
#include <sys/devfs.h>

MALLOC_DECLARE(M_DEVFS);

extern struct vop_ops devfs_vnode_norm_vops;
extern struct vop_ops devfs_vnode_dev_vops;
extern struct lock      devfs_lock;

static int      devfs_vfs_mount (struct mount *mp, char *path, caddr_t data,
                                  struct ucred *cred);
static int      devfs_vfs_statfs (struct mount *mp, struct statfs *sbp,
                                struct ucred *cred);
static int      devfs_vfs_unmount (struct mount *mp, int mntflags);
int             devfs_vfs_root(struct mount *mp, struct vnode **vpp);
static int      devfs_vfs_vget(struct mount *mp, struct vnode *dvp,
                                ino_t ino, struct vnode **vpp);
static int      devfs_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
                                struct fid *fhp, struct vnode **vpp);
static int      devfs_vfs_vptofh(struct vnode *vp, struct fid *fhp);


/*
 * VFS Operations.
 *
 * mount system call
 */
static int
devfs_vfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
{
        struct devfs_mount_info info;
        struct devfs_mnt_data *mnt;
        size_t size;
        int error;

        devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_mount() called!\n");

        if (mp->mnt_flag & MNT_UPDATE)
                return (EOPNOTSUPP);

        if (data == NULL) {
                bzero(&info, sizeof(info));
        } else {
                if ((error = copyin(data, &info, sizeof(info))) != 0)
                        return (error);
        }

        mp->mnt_flag |= MNT_LOCAL;
        mp->mnt_kern_flag |= MNTK_NOSTKMNT | MNTK_ALL_MPSAFE;
        mp->mnt_kern_flag |= MNTK_QUICKHALT;   /* no teardown needed on halt */
        mp->mnt_data = NULL;
        vfs_getnewfsid(mp);

        size = sizeof("devfs") - 1;
        bcopy("devfs", mp->mnt_stat.f_mntfromname, size);
        bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
        copyinstr(path, mp->mnt_stat.f_mntonname,
            sizeof(mp->mnt_stat.f_mntonname) -1, &size);
        devfs_vfs_statfs(mp, &mp->mnt_stat, cred);

        /*
         * XXX: save other mount info passed from userland or so.
         */
        mnt = kmalloc(sizeof(*mnt), M_DEVFS, M_WAITOK | M_ZERO);

        lockmgr(&devfs_lock, LK_EXCLUSIVE);
        mp->mnt_data = (qaddr_t)mnt;

        if (info.flags & DEVFS_MNT_JAIL)
                mnt->jailed = 1;
        else
                mnt->jailed = jailed(cred);

        mnt->leak_count = 0;
        mnt->file_count = 0;
        mnt->mp = mp;
        TAILQ_INIT(&mnt->orphan_list);
        mnt->root_node = devfs_allocp(Nroot, "", NULL, mp, NULL);
        KKASSERT(mnt->root_node);
        lockmgr(&devfs_lock, LK_RELEASE);

        vfs_add_vnodeops(mp, &devfs_vnode_norm_vops, &mp->mnt_vn_norm_ops);
        vfs_add_vnodeops(mp, &devfs_vnode_dev_vops, &mp->mnt_vn_spec_ops);

        devfs_debug(DEVFS_DEBUG_DEBUG, "calling devfs_mount_add\n");
        devfs_mount_add(mnt);

        return (0);
}

/*
 * unmount system call
 */
static int
devfs_vfs_unmount(struct mount *mp, int mntflags)
{
        int error = 0;
        int flags = 0;

        devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_unmount() called!\n");

        if (mntflags & MNT_FORCE)
                flags |= FORCECLOSE;

        error = vflush(mp, 0, flags);

        if (error)
                return (error);
        lockmgr(&devfs_lock, LK_EXCLUSIVE);
        devfs_tracer_orphan_count(mp, 1);
        lockmgr(&devfs_lock, LK_RELEASE);
        devfs_mount_del(DEVFS_MNTDATA(mp));
        kfree(mp->mnt_data, M_DEVFS);
        mp->mnt_data = NULL;

        return (0);
}

/*
 * Sets *vpp to the root procfs vnode, referenced and exclusively locked
 */
int
devfs_vfs_root(struct mount *mp, struct vnode **vpp)
{
        int ret;

        devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_root() called!\n");
        lockmgr(&devfs_lock, LK_EXCLUSIVE);
        ret = devfs_allocv(vpp, DEVFS_MNTDATA(mp)->root_node);
        lockmgr(&devfs_lock, LK_RELEASE);

        return ret;
}

/*
 * Get file system statistics.
 */
static int
devfs_vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
{
        devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_stat() called!\n");
        sbp->f_bsize = DEV_BSIZE;
        sbp->f_iosize = DEV_BSIZE;
        sbp->f_blocks = 2;      /* avoid divide by zero in some df's */
        sbp->f_bfree = 0;
        sbp->f_bavail = 0;
        sbp->f_files = (DEVFS_MNTDATA(mp))?(DEVFS_MNTDATA(mp)->file_count):0;
        sbp->f_ffree = 0;

        if (sbp != &mp->mnt_stat) {
                sbp->f_type = mp->mnt_vfc->vfc_typenum;
                bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
                bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
        }

        return (0);
}

static int
devfs_vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
                 struct fid *fhp, struct vnode **vpp)
{
        struct vnode            *vp;
        struct devfs_fid        *dfhp;

        dfhp = (struct devfs_fid *)fhp;

        if (dfhp->fid_gen != boottime.tv_sec)
                return EINVAL;

        vp = devfs_inode_to_vnode(mp, dfhp->fid_ino);

        if (vp == NULL)
                return ENOENT;

        *vpp = vp;
        return 0;
}

/*
 * Vnode pointer to File handle
 */
static int
devfs_vfs_vptofh(struct vnode *vp, struct fid *fhp)
{
        struct devfs_node       *node;
        struct devfs_fid        *dfhp;

        if ((node = DEVFS_NODE(vp)) != NULL) {
                dfhp = (struct devfs_fid *)fhp;
                dfhp->fid_len = sizeof(struct devfs_fid);
                dfhp->fid_ino = node->d_dir.d_ino;
                dfhp->fid_gen = boottime.tv_sec;
        } else {
                return ENOENT;
        }

        return (0);
}

static int
devfs_vfs_vget(struct mount *mp, struct vnode *dvp,
               ino_t ino, struct vnode **vpp)
{
        struct vnode *vp;
        vp = devfs_inode_to_vnode(mp, ino);

        if (vp == NULL)
                return ENOENT;

        *vpp = vp;
        return 0;
}

static void
devfs_vfs_ncpgen_set(struct mount *mp, struct namecache *ncp)
{
        ncp->nc_namecache_gen = mp->mnt_namecache_gen;
}

static int
devfs_vfs_ncpgen_test(struct mount *mp, struct namecache *ncp)
{
        return (ncp->nc_namecache_gen != mp->mnt_namecache_gen);
}

static struct vfsops devfs_vfsops = {
        .vfs_flags      = 0,
        .vfs_mount      = devfs_vfs_mount,
        .vfs_unmount    = devfs_vfs_unmount,
        .vfs_root       = devfs_vfs_root,
        .vfs_statfs     = devfs_vfs_statfs,
        .vfs_vget       = devfs_vfs_vget,
        .vfs_vptofh     = devfs_vfs_vptofh,
        .vfs_fhtovp     = devfs_vfs_fhtovp,
        .vfs_ncpgen_set = devfs_vfs_ncpgen_set,
        .vfs_ncpgen_test        = devfs_vfs_ncpgen_test
};

VFS_SET(devfs_vfsops, devfs, VFCF_SYNTHETIC | VFCF_MPSAFE);
MODULE_VERSION(devfs, 1);