Function vfs_mount_alloc

freebsd/kern/vfs_mount.c:489–533

* Allocate and initialize the mount point struct. */

 * Allocate and initialize the mount point struct.
 */
struct mount *
vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, const char *fspath,
    struct ucred *cred)
{
	struct mount *mp;

	mp = uma_zalloc(mount_zone, M_WAITOK);
	bzero(&mp->mnt_startzero,
	    __rangeof(struct mount, mnt_startzero, mnt_endzero));
	mp->mnt_kern_flag = 0;
	mp->mnt_flag = 0;
	mp->mnt_rootvnode = NULL;
	mp->mnt_vnodecovered = NULL;
	mp->mnt_op = NULL;
	mp->mnt_vfc = NULL;
	TAILQ_INIT(&mp->mnt_nvnodelist);
	mp->mnt_nvnodelistsize = 0;
	TAILQ_INIT(&mp->mnt_lazyvnodelist);
	mp->mnt_lazyvnodelistsize = 0;
	if (mp->mnt_ref != 0 || mp->mnt_lockref != 0 ||
	    mp->mnt_writeopcount != 0)
		panic("%s: non-zero counters on new mp %p\n", __func__, mp);
	if (mp->mnt_vfs_ops != 1)
		panic("%s: vfs_ops should be 1 but %d found\n", __func__,
		    mp->mnt_vfs_ops);
	(void) vfs_busy(mp, MBF_NOWAIT);
	atomic_add_acq_int(&vfsp->vfc_refcount, 1);
	mp->mnt_op = vfsp->vfc_vfsops;
	mp->mnt_vfc = vfsp;
	mp->mnt_stat.f_type = vfsp->vfc_typenum;
	mp->mnt_gen++;
	strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
	mp->mnt_vnodecovered = vp;
	mp->mnt_cred = crdup(cred);
	mp->mnt_stat.f_owner = cred->cr_uid;
	strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN);
	mp->mnt_iosize_max = DFLTPHYS;
#ifdef MAC
	mac_mount_init(mp);
	mac_mount_create(cred, mp);
#endif
	arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0);
	TAILQ_INIT(&mp->mnt_uppers);
	return (mp);
}

/*
 * Destroy the mount struct previously allocated by vfs_mount_alloc().