1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software donated to Berkeley by 8 * Jan-Simon Pendry. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #ifndef FS_NULL_H 36 #define FS_NULL_H 37 38 #include <sys/ck.h> 39 #include <vm/uma.h> 40 41 #define NULLM_CACHE 0x0001 42 #define NULLM_NOUNPBYPASS 0x0002 43 44 struct null_mount { 45 struct mount *nullm_vfs; 46 struct vnode *nullm_lowerrootvp; /* Ref to lower root vnode */ 47 uint64_t nullm_flags; 48 struct mount_upper_node upper_node; 49 struct mount_upper_node notify_node; 50 }; 51 52 #ifdef _KERNEL 53 /* 54 * A cache of vnode references 55 */ 56 struct null_node { 57 CK_SLIST_ENTRY(null_node) null_hash; /* Hash list */ 58 struct vnode *null_lowervp; /* VREFed once */ 59 struct vnode *null_vnode; /* Back pointer */ 60 u_int null_flags; 61 }; 62 63 #define NULLV_NOUNLOCK 0x0001 64 #define NULLV_DROP 0x0002 65 66 #define MOUNTTONULLMOUNT(mp) ((struct null_mount *)((mp)->mnt_data)) 67 #define VTONULL(vp) ((struct null_node *)(vp)->v_data) 68 #define VTONULL_SMR(vp) ((struct null_node *)vn_load_v_data_smr(vp)) 69 #define NULLTOV(xp) ((xp)->null_vnode) 70 71 int nullfs_init(struct vfsconf *vfsp); 72 int nullfs_uninit(struct vfsconf *vfsp); 73 int null_nodeget(struct mount *mp, struct vnode *target, struct vnode **vpp); 74 struct vnode *null_hashget(struct mount *mp, struct vnode *lowervp); 75 void null_hashrem(struct null_node *xp); 76 int null_bypass(struct vop_generic_args *ap); 77 78 #ifdef DIAGNOSTIC 79 struct vnode *null_checkvp(struct vnode *vp, char *fil, int lno); 80 #define NULLVPTOLOWERVP(vp) null_checkvp((vp), __FILE__, __LINE__) 81 #else 82 #define NULLVPTOLOWERVP(vp) (VTONULL(vp)->null_lowervp) 83 #endif 84 85 extern struct vop_vector null_vnodeops; 86 extern struct vop_vector null_vnodeops_no_unp_bypass; 87 88 static inline bool 89 null_is_nullfs_vnode(struct vnode *vp) 90 { 91 const struct vop_vector *op; 92 93 op = vp->v_op; 94 return (op == &null_vnodeops || op == &null_vnodeops_no_unp_bypass); 95 } 96 97 extern uma_zone_t null_node_zone; 98 99 #ifdef NULLFS_DEBUG 100 #define NULLFSDEBUG(format, args...) printf(format ,## args) 101 #else 102 #define NULLFSDEBUG(format, args...) 103 #endif /* NULLFS_DEBUG */ 104 105 #endif /* _KERNEL */ 106 107 #endif 108