1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 22 /* All Rights Reserved */ 23 24 25 /* 26 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 27 * Use is subject to license terms. 28 */ 29 30 #ifndef _SYS_FS_SNODE_H 31 #define _SYS_FS_SNODE_H 32 33 #pragma ident "%Z%%M% %I% %E% SMI" 34 35 #include <sys/types.h> 36 #include <sys/t_lock.h> 37 #include <sys/cred.h> 38 #include <sys/vnode.h> 39 40 /* 41 * The snode represents a special file in any filesystem. There is 42 * one snode for each active special file. Filesystems that support 43 * special files use specvp(vp, dev, type, cr) to convert a normal 44 * vnode to a special vnode in the ops lookup() and create(). 45 * 46 * To handle having multiple snodes that represent the same 47 * underlying device vnode without cache aliasing problems, 48 * the s_commonvp is used to point to the "common" vnode used for 49 * caching data. If an snode is created internally by the kernel, 50 * then the s_realvp field is NULL and s_commonvp points to s_vnode. 51 * The other snodes which are created as a result of a lookup of a 52 * device in a file system have s_realvp pointing to the vp which 53 * represents the device in the file system while the s_commonvp points 54 * into the "common" vnode for the device in another snode. 55 */ 56 57 /* 58 * Include SUNDDI type definitions so that the s_dip tag doesn't urk. 59 */ 60 #include <sys/dditypes.h> 61 62 #ifdef __cplusplus 63 extern "C" { 64 #endif 65 66 struct snode { 67 /* These fields are protected by stable_lock */ 68 struct snode *s_next; /* must be first */ 69 struct vnode *s_vnode; /* vnode associated with this snode */ 70 /* 71 * These fields are initialized once. 72 */ 73 struct vnode *s_realvp; /* vnode for the fs entry (if any) */ 74 struct vnode *s_commonvp; /* common device vnode */ 75 dev_t s_dev; /* device the snode represents */ 76 dev_info_t *s_dip; /* dev_info (common snode only) */ 77 /* 78 * Doesn't always need to be updated atomically because it is a hint. 79 * No lock required. 80 */ 81 u_offset_t s_nextr; /* next byte read offset (read-ahead) */ 82 83 /* These fields are protected by spec_syncbusy */ 84 struct snode *s_list; /* used for syncing */ 85 /* These fields are protected by s_lock */ 86 struct devplcy *s_plcy; /* device node open policy (cs only) */ 87 u_offset_t s_size; /* block device size in bytes */ 88 ushort_t s_flag; /* flags, see below */ 89 dev_t s_fsid; /* file system identifier */ 90 time_t s_atime; /* time of last access */ 91 time_t s_mtime; /* time of last modification */ 92 time_t s_ctime; /* time of last attributes change */ 93 int s_count; /* count of opened references */ 94 long s_mapcnt; /* count of mappings of pages */ 95 /* The locks themselves */ 96 kmutex_t s_lock; /* protects snode fields */ 97 kcondvar_t s_cv; /* synchronize open/closes */ 98 }; 99 100 /* flags */ 101 #define SUPD 0x01 /* update device access time */ 102 #define SACC 0x02 /* update device modification time */ 103 #define SCHG 0x04 /* update device change time */ 104 #define SPRIV 0x08 /* file open for private access */ 105 #define SLOFFSET 0x10 /* device takes 64-bit uio offsets */ 106 #define SLOCKED 0x20 /* use to serialize open/closes */ 107 #define SWANT 0x40 /* some process waiting on lock */ 108 #define SANYOFFSET 0x80 /* device takes any uio offset */ 109 #define SCLONE 0x100 /* represents a cloned device */ 110 #define SNEEDCLOSE 0x200 /* needs driver close call */ 111 #define SDIPSET 0x400 /* the vnode has an association with */ 112 /* the driver, even though it may */ 113 /* not currently have an association */ 114 /* with a specific hardware instance */ 115 /* if s_dip is NULL */ 116 #define SSIZEVALID 0x800 /* s_size field is valid */ 117 #define SMUXED 0x1000 /* this snode is a stream that has */ 118 /* been multiplexed */ 119 #define SSELFCLONE 0x2000 /* represents a self cloning device */ 120 #define SNOFLUSH 0x4000 /* do not flush device on fsync */ 121 122 #ifdef _KERNEL 123 /* 124 * Convert between vnode and snode 125 */ 126 #define VTOS(vp) ((struct snode *)((vp)->v_data)) 127 #define VTOCS(vp) (VTOS(VTOS(vp)->s_commonvp)) 128 #define STOV(sp) ((sp)->s_vnode) 129 130 131 /* 132 * Forward declarations 133 */ 134 struct vfssw; 135 struct cred; 136 137 extern struct vfs spec_vfs; 138 extern struct vfsops spec_vfsops; 139 extern struct kmem_cache *snode_cache; 140 141 /* 142 * specfs functions 143 */ 144 offset_t spec_maxoffset(struct vnode *); 145 struct vnodeops *spec_getvnodeops(void); 146 struct vnode *specvp(struct vnode *, dev_t, vtype_t, struct cred *); 147 struct vnode *makespecvp(dev_t, vtype_t); 148 struct vnode *other_specvp(struct vnode *); 149 struct vnode *common_specvp(struct vnode *); 150 struct vnode *specfind(dev_t, vtype_t); 151 struct vnode *commonvp(dev_t, vtype_t); 152 struct vnode *makectty(vnode_t *); 153 void sdelete(struct snode *); 154 void smark(struct snode *, int); 155 int specinit(int, char *); 156 int device_close(struct vnode *, int, struct cred *); 157 int spec_putpage(struct vnode *, offset_t, size_t, int, struct cred *); 158 int spec_segmap(dev_t, off_t, struct as *, caddr_t *, off_t, 159 uint_t, uint_t, uint_t, cred_t *); 160 struct vnode *specvp_devfs(struct vnode *, dev_t, vtype_t, 161 struct cred *, dev_info_t *); 162 void spec_assoc_vp_with_devi(struct vnode *, dev_info_t *); 163 dev_info_t *spec_hold_devi_by_vp(struct vnode *); 164 int spec_sync(struct vfs *, short, struct cred *); 165 void spec_snode_walk(int (*callback)(struct snode *, void *), void *); 166 int spec_devi_open_count(struct snode *, dev_info_t **); 167 int spec_is_clone(struct vnode *); 168 int spec_is_selfclone(struct vnode *); 169 170 171 /* 172 * UNKNOWN_SIZE: If driver does not support the [Ss]ize or [Nn]blocks property 173 * then the size is assumed to be "infinite". Note that this "infinite" value 174 * may need to be converted to a smaller "infinite" value to avoid EOVERFLOW at 175 * field width conversion locations like the stat(2) and NFS code running 176 * against a special file. Special file code outside specfs may check the 177 * type of the vnode (VCHR|VBLK) and use MAXOFFSET_T directly to detect 178 * UNKNOWN_SIZE. 179 */ 180 #define UNKNOWN_SIZE MAXOFFSET_T 181 182 /* 183 * SPEC_MAXOFFSET_T: Solaris does not fully support 64-bit offsets for D_64BIT 184 * (SLOFFSET) block drivers on a 32-bit kernels: daddr_t is still a signed 185 * 32-bit quantity - which limits the byte offset to 1TB. This issue goes 186 * beyond a driver needing to convert from daddr_t to diskaddr_t if it sets 187 * D_64BIT. Many of the DDI interfaces which take daddr_t arguments have no 188 * 64-bit counterpart (bioclone, blkflush, bread, bread_common, breada, getblk, 189 * getblk_common). SPEC_MAXOFFSET_T is used by 32-bit kernel code to enforce 190 * this restriction. 191 */ 192 #ifdef _ILP32 193 #ifdef _LONGLONG_TYPE 194 #define SPEC_MAXOFFSET_T ((1LL << ((NBBY * sizeof (daddr32_t)) + \ 195 DEV_BSHIFT - 1)) - 1) 196 #else /* !defined(_LONGLONG_TYPE) */ 197 #define SPEC_MAXOFFSET_T MAXOFF_T 198 #endif /* _LONGLONG_TYPE */ 199 #endif /* _ILP32 */ 200 201 /* 202 * Snode lookup stuff. 203 * These routines maintain a table of snodes hashed by dev so 204 * that the snode for an dev can be found if it already exists. 205 * NOTE: STABLESIZE must be a power of 2 for STABLEHASH to work! 206 */ 207 208 #define STABLESIZE 256 209 #define STABLEHASH(dev) ((getmajor(dev) + getminor(dev)) & (STABLESIZE - 1)) 210 extern struct snode *stable[]; 211 extern kmutex_t stable_lock; 212 extern kmutex_t spec_syncbusy; 213 214 /* 215 * Variables used by during asynchronous VOP_PUTPAGE operations. 216 */ 217 extern struct async_reqs *spec_async_reqs; /* async request list */ 218 extern kmutex_t spec_async_lock; /* lock to protect async list */ 219 220 #endif /* _KERNEL */ 221 222 #ifdef __cplusplus 223 } 224 #endif 225 226 #endif /* _SYS_FS_SNODE_H */ 227