tmpfs.h revision 1.9.2.4
1 1.9.2.4 christos /* $NetBSD: tmpfs.h,v 1.9.2.4 2005/12/11 10:29:11 christos Exp $ */ 2 1.9.2.2 skrll 3 1.9.2.2 skrll /* 4 1.9.2.2 skrll * Copyright (c) 2005 The NetBSD Foundation, Inc. 5 1.9.2.2 skrll * All rights reserved. 6 1.9.2.2 skrll * 7 1.9.2.2 skrll * This code is derived from software contributed to The NetBSD Foundation 8 1.9.2.2 skrll * by Julio M. Merino Vidal, developed as part of Google's Summer of Code 9 1.9.2.2 skrll * 2005 program. 10 1.9.2.2 skrll * 11 1.9.2.2 skrll * Redistribution and use in source and binary forms, with or without 12 1.9.2.2 skrll * modification, are permitted provided that the following conditions 13 1.9.2.2 skrll * are met: 14 1.9.2.2 skrll * 1. Redistributions of source code must retain the above copyright 15 1.9.2.2 skrll * notice, this list of conditions and the following disclaimer. 16 1.9.2.2 skrll * 2. Redistributions in binary form must reproduce the above copyright 17 1.9.2.2 skrll * notice, this list of conditions and the following disclaimer in the 18 1.9.2.2 skrll * documentation and/or other materials provided with the distribution. 19 1.9.2.2 skrll * 3. All advertising materials mentioning features or use of this software 20 1.9.2.2 skrll * must display the following acknowledgement: 21 1.9.2.2 skrll * This product includes software developed by the NetBSD 22 1.9.2.2 skrll * Foundation, Inc. and its contributors. 23 1.9.2.2 skrll * 4. Neither the name of The NetBSD Foundation nor the names of its 24 1.9.2.2 skrll * contributors may be used to endorse or promote products derived 25 1.9.2.2 skrll * from this software without specific prior written permission. 26 1.9.2.2 skrll * 27 1.9.2.2 skrll * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 1.9.2.2 skrll * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 1.9.2.2 skrll * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 1.9.2.2 skrll * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 1.9.2.2 skrll * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 1.9.2.2 skrll * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 1.9.2.2 skrll * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 1.9.2.2 skrll * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 1.9.2.2 skrll * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 1.9.2.2 skrll * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 1.9.2.2 skrll * POSSIBILITY OF SUCH DAMAGE. 38 1.9.2.2 skrll */ 39 1.9.2.2 skrll 40 1.9.2.4 christos #ifndef _FS_TMPFS_TMPFS_H_ 41 1.9.2.4 christos #define _FS_TMPFS_TMPFS_H_ 42 1.9.2.2 skrll 43 1.9.2.2 skrll /* --------------------------------------------------------------------- 44 1.9.2.2 skrll * KERNEL-SPECIFIC DEFINITIONS 45 1.9.2.2 skrll * --------------------------------------------------------------------- */ 46 1.9.2.2 skrll 47 1.9.2.2 skrll #if defined(_KERNEL) 48 1.9.2.2 skrll 49 1.9.2.2 skrll #include <sys/dirent.h> 50 1.9.2.2 skrll #include <sys/mount.h> 51 1.9.2.2 skrll #include <sys/queue.h> 52 1.9.2.2 skrll #include <sys/vnode.h> 53 1.9.2.2 skrll 54 1.9.2.2 skrll #include <fs/tmpfs/tmpfs_pool.h> 55 1.9.2.2 skrll 56 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 57 1.9.2.2 skrll 58 1.9.2.2 skrll /* 59 1.9.2.2 skrll * Internal representation of a tmpfs directory entry. 60 1.9.2.2 skrll */ 61 1.9.2.2 skrll struct tmpfs_dirent { 62 1.9.2.2 skrll TAILQ_ENTRY(tmpfs_dirent) td_entries; 63 1.9.2.2 skrll 64 1.9.2.2 skrll /* Length of the name stored in this directory entry. This avoids 65 1.9.2.2 skrll * the need to recalculate it every time the name is used. */ 66 1.9.2.2 skrll uint16_t td_namelen; 67 1.9.2.2 skrll 68 1.9.2.2 skrll /* The name of the entry, allocated from a string pool. This 69 1.9.2.2 skrll * string is not required to be zero-terminated; therefore, the 70 1.9.2.2 skrll * td_namelen field must always be used when accessing its value. */ 71 1.9.2.2 skrll char * td_name; 72 1.9.2.2 skrll 73 1.9.2.2 skrll /* Pointer to the node this entry refers to. */ 74 1.9.2.2 skrll struct tmpfs_node * td_node; 75 1.9.2.2 skrll }; 76 1.9.2.2 skrll 77 1.9.2.2 skrll /* A directory in tmpfs holds a sorted list of directory entries, which in 78 1.9.2.2 skrll * turn point to other files (which can be directories themselves). 79 1.9.2.2 skrll * 80 1.9.2.2 skrll * In tmpfs, this list is managed by a tail queue, whose head is defined by 81 1.9.2.2 skrll * the struct tmpfs_dir type. 82 1.9.2.2 skrll * 83 1.9.2.2 skrll * It is imporant to notice that directories do not have entries for . and 84 1.9.2.2 skrll * .. as other file systems do. These can be generated when requested 85 1.9.2.2 skrll * based on information available by other means, such as the pointer to 86 1.9.2.2 skrll * the node itself in the former case or the pointer to the parent directory 87 1.9.2.2 skrll * in the latter case. This is done to simplify tmpfs's code and, more 88 1.9.2.2 skrll * importantly, to remove redundancy. */ 89 1.9.2.2 skrll TAILQ_HEAD(tmpfs_dir, tmpfs_dirent); 90 1.9.2.2 skrll 91 1.9.2.2 skrll #define TMPFS_DIRCOOKIE(dirent) ((off_t)(uintptr_t)(dirent)) 92 1.9.2.2 skrll #define TMPFS_DIRCOOKIE_DOT 0 93 1.9.2.2 skrll #define TMPFS_DIRCOOKIE_DOTDOT 1 94 1.9.2.2 skrll #define TMPFS_DIRCOOKIE_EOF 2 95 1.9.2.2 skrll 96 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 97 1.9.2.2 skrll 98 1.9.2.2 skrll /* 99 1.9.2.2 skrll * Internal representation of a tmpfs file system node. 100 1.9.2.2 skrll * 101 1.9.2.2 skrll * This structure is splitted in two parts: one holds attributes common 102 1.9.2.2 skrll * to all file types and the other holds data that is only applicable to 103 1.9.2.2 skrll * a particular type. The code must be careful to only access those 104 1.9.2.2 skrll * attributes that are actually allowed by the node's type. 105 1.9.2.2 skrll */ 106 1.9.2.2 skrll struct tmpfs_node { 107 1.9.2.2 skrll /* Doubly-linked list entry which links all existing nodes for a 108 1.9.2.2 skrll * single file system. This is provided to ease the removal of 109 1.9.2.2 skrll * all nodes during the unmount operation. */ 110 1.9.2.2 skrll LIST_ENTRY(tmpfs_node) tn_entries; 111 1.9.2.2 skrll 112 1.9.2.2 skrll /* The node's type. Any of 'VBLK', 'VCHR', 'VDIR', 'VFIFO', 113 1.9.2.2 skrll * 'VLNK', 'VREG' and 'VSOCK' is allowed. The usage of vnode 114 1.9.2.2 skrll * types instead of a custom enumeration is to make things simpler 115 1.9.2.2 skrll * and faster, as we do not need to convert between two types. */ 116 1.9.2.2 skrll enum vtype tn_type; 117 1.9.2.2 skrll 118 1.9.2.2 skrll /* Node identifier. */ 119 1.9.2.2 skrll ino_t tn_id; 120 1.9.2.2 skrll 121 1.9.2.2 skrll /* Node's internal status. This is used by several file system 122 1.9.2.2 skrll * operations to do modifications to the node in a delayed 123 1.9.2.2 skrll * fashion. */ 124 1.9.2.2 skrll int tn_status; 125 1.9.2.2 skrll #define TMPFS_NODE_ACCESSED (1 << 1) 126 1.9.2.2 skrll #define TMPFS_NODE_MODIFIED (1 << 2) 127 1.9.2.2 skrll #define TMPFS_NODE_CHANGED (1 << 3) 128 1.9.2.2 skrll 129 1.9.2.2 skrll /* The node size. It does not necessarily match the real amount 130 1.9.2.2 skrll * of memory consumed by it. */ 131 1.9.2.2 skrll off_t tn_size; 132 1.9.2.2 skrll 133 1.9.2.2 skrll /* Generic node attributes. */ 134 1.9.2.2 skrll uid_t tn_uid; 135 1.9.2.2 skrll gid_t tn_gid; 136 1.9.2.2 skrll mode_t tn_mode; 137 1.9.2.2 skrll int tn_flags; 138 1.9.2.2 skrll nlink_t tn_links; 139 1.9.2.2 skrll struct timespec tn_atime; 140 1.9.2.2 skrll struct timespec tn_mtime; 141 1.9.2.2 skrll struct timespec tn_ctime; 142 1.9.2.2 skrll struct timespec tn_birthtime; 143 1.9.2.2 skrll unsigned long tn_gen; 144 1.9.2.2 skrll 145 1.9.2.2 skrll /* Head of byte-level lock list (used by tmpfs_advlock). */ 146 1.9.2.2 skrll struct lockf * tn_lockf; 147 1.9.2.2 skrll 148 1.9.2.2 skrll /* As there is a single vnode for each active file within the 149 1.9.2.2 skrll * system, care has to be taken to avoid allocating more than one 150 1.9.2.2 skrll * vnode per file. In order to do this, a bidirectional association 151 1.9.2.2 skrll * is kept between vnodes and nodes. 152 1.9.2.2 skrll * 153 1.9.2.2 skrll * Whenever a vnode is allocated, its v_data field is updated to 154 1.9.2.2 skrll * point to the node it references. At the same time, the node's 155 1.9.2.2 skrll * tn_vnode field is modified to point to the new vnode representing 156 1.9.2.2 skrll * it. Further attempts to allocate a vnode for this same node will 157 1.9.2.2 skrll * result in returning a new reference to the value stored in 158 1.9.2.2 skrll * tn_vnode. 159 1.9.2.2 skrll * 160 1.9.2.2 skrll * May be NULL when the node is unused (that is, no vnode has been 161 1.9.2.2 skrll * allocated for it or it has been reclaimed). */ 162 1.9.2.2 skrll struct vnode * tn_vnode; 163 1.9.2.2 skrll 164 1.9.2.2 skrll /* Pointer to the node returned by tmpfs_lookup() after doing a 165 1.9.2.2 skrll * delete or a rename lookup; its value is only valid in these two 166 1.9.2.2 skrll * situations. In case we were looking up . or .., it holds a null 167 1.9.2.2 skrll * pointer. */ 168 1.9.2.2 skrll struct tmpfs_dirent * tn_lookup_dirent; 169 1.9.2.2 skrll 170 1.9.2.2 skrll union { 171 1.9.2.2 skrll /* Valid when tn_type == VBLK || tn_type == VCHR. */ 172 1.9.2.2 skrll struct { 173 1.9.2.2 skrll dev_t tn_rdev; 174 1.9.2.2 skrll }; 175 1.9.2.2 skrll 176 1.9.2.2 skrll /* Valid when tn_type == VDIR. */ 177 1.9.2.2 skrll struct { 178 1.9.2.2 skrll /* Pointer to the parent directory. The root 179 1.9.2.2 skrll * directory has a pointer to itself in this field; 180 1.9.2.2 skrll * this property identifies the root node. */ 181 1.9.2.2 skrll struct tmpfs_node * tn_parent; 182 1.9.2.2 skrll 183 1.9.2.2 skrll /* Head of a tail-queue that links the contents of 184 1.9.2.2 skrll * the directory together. See above for a 185 1.9.2.2 skrll * description of its contents. */ 186 1.9.2.2 skrll struct tmpfs_dir tn_dir; 187 1.9.2.2 skrll 188 1.9.2.2 skrll /* Number and pointer of the first directory entry 189 1.9.2.2 skrll * returned by the readdir operation if it were 190 1.9.2.2 skrll * called again to continue reading data from the 191 1.9.2.2 skrll * same directory as before. This is used to speed 192 1.9.2.2 skrll * up reads of long directories, assuming that no 193 1.9.2.2 skrll * more than one read is in progress at a given time. 194 1.9.2.2 skrll * Otherwise, these values are discarded and a linear 195 1.9.2.2 skrll * scan is performed from the beginning up to the 196 1.9.2.2 skrll * point where readdir starts returning values. */ 197 1.9.2.2 skrll off_t tn_readdir_lastn; 198 1.9.2.2 skrll struct tmpfs_dirent * tn_readdir_lastp; 199 1.9.2.2 skrll }; 200 1.9.2.2 skrll 201 1.9.2.2 skrll /* Valid when tn_type == VLNK. */ 202 1.9.2.2 skrll struct { 203 1.9.2.2 skrll /* The link's target, allocated from a string pool. */ 204 1.9.2.2 skrll char * tn_link; 205 1.9.2.2 skrll }; 206 1.9.2.2 skrll 207 1.9.2.2 skrll /* Valid when tn_type == VREG. */ 208 1.9.2.2 skrll struct { 209 1.9.2.2 skrll /* The contents of regular files stored in a tmpfs 210 1.9.2.2 skrll * file system are represented by a single anonymous 211 1.9.2.2 skrll * memory object (aobj, for short). The aobj provides 212 1.9.2.2 skrll * direct access to any position within the file, 213 1.9.2.2 skrll * because its contents are always mapped in a 214 1.9.2.2 skrll * contiguous region of virtual memory. It is a task 215 1.9.2.2 skrll * of the memory management subsystem (see uvm(9)) to 216 1.9.2.2 skrll * issue the required page ins or page outs whenever 217 1.9.2.2 skrll * a position within the file is accessed. */ 218 1.9.2.2 skrll struct uvm_object * tn_aobj; 219 1.9.2.2 skrll size_t tn_aobj_pages; 220 1.9.2.2 skrll }; 221 1.9.2.2 skrll }; 222 1.9.2.2 skrll }; 223 1.9.2.2 skrll LIST_HEAD(tmpfs_node_list, tmpfs_node); 224 1.9.2.2 skrll 225 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 226 1.9.2.2 skrll 227 1.9.2.2 skrll /* 228 1.9.2.2 skrll * Internal representation of a tmpfs mount point. 229 1.9.2.2 skrll */ 230 1.9.2.2 skrll struct tmpfs_mount { 231 1.9.2.2 skrll /* Maximum number of memory pages available for use by the file 232 1.9.2.2 skrll * system, set during mount time. This variable must never be 233 1.9.2.2 skrll * used directly as it may be bigger that the current amount of 234 1.9.2.2 skrll * free memory; in the extreme case, it will hold the SIZE_MAX 235 1.9.2.2 skrll * value. Instead, use the TMPFS_PAGES_MAX macro. */ 236 1.9.2.2 skrll size_t tm_pages_max; 237 1.9.2.2 skrll 238 1.9.2.2 skrll /* Number of pages in use by the file system. Cannot be bigger 239 1.9.2.2 skrll * than the value returned by TMPFS_PAGES_MAX in any case. */ 240 1.9.2.2 skrll size_t tm_pages_used; 241 1.9.2.2 skrll 242 1.9.2.2 skrll /* Pointer to the node representing the root directory of this 243 1.9.2.2 skrll * file system. */ 244 1.9.2.2 skrll struct tmpfs_node * tm_root; 245 1.9.2.2 skrll 246 1.9.2.2 skrll /* Maximum number of possible nodes for this file system; set 247 1.9.2.2 skrll * during mount time. We need a hard limit on the maximum number 248 1.9.2.2 skrll * of nodes to avoid allocating too much of them; their objects 249 1.9.2.2 skrll * cannot be released until the file system is unmounted. 250 1.9.2.2 skrll * Otherwise, we could easily run out of memory by creating lots 251 1.9.2.2 skrll * of empty files and then simply removing them. */ 252 1.9.2.2 skrll ino_t tm_nodes_max; 253 1.9.2.2 skrll 254 1.9.2.2 skrll /* Number of nodes currently allocated. This number only grows. 255 1.9.2.2 skrll * When it reaches tm_nodes_max, no more new nodes can be allocated. 256 1.9.2.2 skrll * Of course, the old, unused ones can be reused. */ 257 1.9.2.2 skrll ino_t tm_nodes_last; 258 1.9.2.2 skrll 259 1.9.2.2 skrll /* Nodes are organized in two different lists. The used list 260 1.9.2.2 skrll * contains all nodes that are currently used by the file system; 261 1.9.2.2 skrll * i.e., they refer to existing files. The available list contains 262 1.9.2.2 skrll * all nodes that are currently available for use by new files. 263 1.9.2.2 skrll * Nodes must be kept in this list (instead of deleting them) 264 1.9.2.2 skrll * because we need to keep track of their generation number (tn_gen 265 1.9.2.2 skrll * field). 266 1.9.2.2 skrll * 267 1.9.2.2 skrll * Note that nodes are lazily allocated: if the available list is 268 1.9.2.2 skrll * empty and we have enough space to create more nodes, they will be 269 1.9.2.2 skrll * created and inserted in the used list. Once these are released, 270 1.9.2.2 skrll * they will go into the available list, remaining alive until the 271 1.9.2.2 skrll * file system is unmounted. */ 272 1.9.2.2 skrll struct tmpfs_node_list tm_nodes_used; 273 1.9.2.2 skrll struct tmpfs_node_list tm_nodes_avail; 274 1.9.2.2 skrll 275 1.9.2.2 skrll /* Pools used to store file system meta data. These are not shared 276 1.9.2.2 skrll * across several instances of tmpfs for the reasons described in 277 1.9.2.2 skrll * tmpfs_pool.c. */ 278 1.9.2.2 skrll struct tmpfs_pool tm_dirent_pool; 279 1.9.2.2 skrll struct tmpfs_pool tm_node_pool; 280 1.9.2.2 skrll struct tmpfs_str_pool tm_str_pool; 281 1.9.2.2 skrll }; 282 1.9.2.2 skrll 283 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 284 1.9.2.2 skrll 285 1.9.2.2 skrll /* 286 1.9.2.2 skrll * This structure maps a file identifier to a tmpfs node. Used by the 287 1.9.2.2 skrll * NFS code. 288 1.9.2.2 skrll */ 289 1.9.2.2 skrll struct tmpfs_fid { 290 1.9.2.2 skrll uint16_t tf_len; 291 1.9.2.2 skrll uint16_t tf_pad; 292 1.9.2.2 skrll ino_t tf_id; 293 1.9.2.2 skrll unsigned long tf_gen; 294 1.9.2.2 skrll }; 295 1.9.2.2 skrll 296 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 297 1.9.2.2 skrll 298 1.9.2.2 skrll /* 299 1.9.2.2 skrll * Prototypes for tmpfs_subr.c. 300 1.9.2.2 skrll */ 301 1.9.2.2 skrll 302 1.9.2.2 skrll int tmpfs_alloc_node(struct tmpfs_mount *, enum vtype, 303 1.9.2.2 skrll uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *, 304 1.9.2.2 skrll char *, dev_t, struct proc *, struct tmpfs_node **); 305 1.9.2.2 skrll void tmpfs_free_node(struct tmpfs_mount *, struct tmpfs_node *); 306 1.9.2.2 skrll int tmpfs_alloc_dirent(struct tmpfs_mount *, struct tmpfs_node *, 307 1.9.2.2 skrll const char *, uint16_t, struct tmpfs_dirent **); 308 1.9.2.2 skrll void tmpfs_free_dirent(struct tmpfs_mount *, struct tmpfs_dirent *, 309 1.9.2.2 skrll boolean_t); 310 1.9.2.2 skrll int tmpfs_alloc_vp(struct mount *, struct tmpfs_node *, struct vnode **); 311 1.9.2.2 skrll void tmpfs_free_vp(struct vnode *); 312 1.9.2.2 skrll int tmpfs_alloc_file(struct vnode *, struct vnode **, struct vattr *, 313 1.9.2.2 skrll struct componentname *, char *); 314 1.9.2.2 skrll void tmpfs_dir_attach(struct vnode *, struct tmpfs_dirent *); 315 1.9.2.2 skrll void tmpfs_dir_detach(struct vnode *, struct tmpfs_dirent *); 316 1.9.2.2 skrll struct tmpfs_dirent * tmpfs_dir_lookup(struct tmpfs_node *node, 317 1.9.2.2 skrll struct componentname *cnp); 318 1.9.2.2 skrll int tmpfs_dir_getdotdent(struct tmpfs_node *, struct uio *); 319 1.9.2.2 skrll int tmpfs_dir_getdotdotdent(struct tmpfs_node *, struct uio *); 320 1.9.2.2 skrll struct tmpfs_dirent * tmpfs_dir_lookupbycookie(struct tmpfs_node *, off_t); 321 1.9.2.2 skrll int tmpfs_dir_getdents(struct tmpfs_node *, struct uio *, off_t *); 322 1.9.2.2 skrll int tmpfs_reg_resize(struct vnode *, off_t); 323 1.9.2.2 skrll size_t tmpfs_mem_info(boolean_t); 324 1.9.2.2 skrll int tmpfs_chflags(struct vnode *, int, struct ucred *, struct proc *); 325 1.9.2.2 skrll int tmpfs_chmod(struct vnode *, mode_t, struct ucred *, struct proc *); 326 1.9.2.2 skrll int tmpfs_chown(struct vnode *, uid_t, gid_t, struct ucred *, 327 1.9.2.2 skrll struct proc *); 328 1.9.2.2 skrll int tmpfs_chsize(struct vnode *, u_quad_t, struct ucred *, struct proc *); 329 1.9.2.2 skrll int tmpfs_chtimes(struct vnode *, struct timespec *, struct timespec *, 330 1.9.2.3 skrll int, struct ucred *, struct lwp *); 331 1.9.2.2 skrll void tmpfs_itimes(struct vnode *, const struct timespec *, 332 1.9.2.2 skrll const struct timespec *); 333 1.9.2.2 skrll 334 1.9.2.2 skrll void tmpfs_update(struct vnode *, const struct timespec *, 335 1.9.2.2 skrll const struct timespec *, int); 336 1.9.2.2 skrll int tmpfs_truncate(struct vnode *, off_t); 337 1.9.2.2 skrll 338 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 339 1.9.2.2 skrll 340 1.9.2.2 skrll /* 341 1.9.2.2 skrll * Convenience macros to simplify some logical expressions. 342 1.9.2.2 skrll */ 343 1.9.2.2 skrll #define IMPLIES(a, b) (!(a) || (b)) 344 1.9.2.2 skrll #define IFF(a, b) (IMPLIES(a, b) && IMPLIES(b, a)) 345 1.9.2.2 skrll 346 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 347 1.9.2.2 skrll 348 1.9.2.2 skrll /* 349 1.9.2.2 skrll * Checks that the directory entry pointed by 'de' matches the name 'name' 350 1.9.2.2 skrll * with a length of 'len'. 351 1.9.2.2 skrll */ 352 1.9.2.2 skrll #define TMPFS_DIRENT_MATCHES(de, name, len) \ 353 1.9.2.2 skrll (de->td_namelen == (uint16_t)len && \ 354 1.9.2.2 skrll memcmp((de)->td_name, (name), (de)->td_namelen) == 0) 355 1.9.2.2 skrll 356 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 357 1.9.2.2 skrll 358 1.9.2.2 skrll /* 359 1.9.2.2 skrll * Ensures that the node pointed by 'node' is a directory and that its 360 1.9.2.2 skrll * contents are consistent with respect to directories. 361 1.9.2.2 skrll */ 362 1.9.2.2 skrll #define TMPFS_VALIDATE_DIR(node) \ 363 1.9.2.2 skrll KASSERT((node)->tn_type == VDIR); \ 364 1.9.2.2 skrll KASSERT((node)->tn_size % sizeof(struct tmpfs_dirent) == 0); \ 365 1.9.2.2 skrll KASSERT((node)->tn_readdir_lastp == NULL || \ 366 1.9.2.2 skrll TMPFS_DIRCOOKIE((node)->tn_readdir_lastp) == (node)->tn_readdir_lastn); 367 1.9.2.2 skrll 368 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 369 1.9.2.2 skrll 370 1.9.2.2 skrll /* 371 1.9.2.2 skrll * Memory management stuff. 372 1.9.2.2 skrll */ 373 1.9.2.2 skrll 374 1.9.2.2 skrll /* Amount of memory pages to reserve for the system (e.g., to not use by 375 1.9.2.2 skrll * tmpfs). 376 1.9.2.2 skrll * XXX: Should this be tunable through sysctl, for instance? */ 377 1.9.2.2 skrll #define TMPFS_PAGES_RESERVED (4 * 1024 * 1024 / PAGE_SIZE) 378 1.9.2.2 skrll 379 1.9.2.2 skrll /* Returns the maximum size allowed for a tmpfs file system. This macro 380 1.9.2.2 skrll * must be used instead of directly retrieving the value from tm_pages_max. 381 1.9.2.2 skrll * The reason is that the size of a tmpfs file system is dynamic: it lets 382 1.9.2.2 skrll * the user store files as long as there is enough free memory (including 383 1.9.2.2 skrll * physical memory and swap space). Therefore, the amount of memory to be 384 1.9.2.2 skrll * used is either the limit imposed by the user during mount time or the 385 1.9.2.2 skrll * amount of available memory, whichever is lower. To avoid consuming all 386 1.9.2.2 skrll * the memory for a given mount point, the system will always reserve a 387 1.9.2.2 skrll * minimum of TMPFS_PAGES_RESERVED pages, which is also taken into account 388 1.9.2.2 skrll * by this macro (see above). */ 389 1.9.2.2 skrll static inline size_t 390 1.9.2.2 skrll TMPFS_PAGES_MAX(struct tmpfs_mount *tmp) 391 1.9.2.2 skrll { 392 1.9.2.2 skrll size_t freepages; 393 1.9.2.2 skrll 394 1.9.2.2 skrll freepages = tmpfs_mem_info(FALSE); 395 1.9.2.2 skrll if (freepages < TMPFS_PAGES_RESERVED) 396 1.9.2.2 skrll freepages = 0; 397 1.9.2.2 skrll else 398 1.9.2.2 skrll freepages -= TMPFS_PAGES_RESERVED; 399 1.9.2.2 skrll 400 1.9.2.2 skrll return MIN(tmp->tm_pages_max, freepages + tmp->tm_pages_used); 401 1.9.2.2 skrll } 402 1.9.2.2 skrll 403 1.9.2.2 skrll /* Returns the available space for the given file system. */ 404 1.9.2.2 skrll #define TMPFS_PAGES_AVAIL(tmp) (TMPFS_PAGES_MAX(tmp) - (tmp)->tm_pages_used) 405 1.9.2.2 skrll 406 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 407 1.9.2.2 skrll 408 1.9.2.2 skrll /* 409 1.9.2.2 skrll * Macros/functions to convert from generic data structures to tmpfs 410 1.9.2.2 skrll * specific ones. 411 1.9.2.2 skrll * 412 1.9.2.2 skrll * Macros are used when no sanity checks have to be done, as they provide 413 1.9.2.2 skrll * the fastest conversion. On the other hand, inlined functions are used 414 1.9.2.2 skrll * when expensive sanity checks are enabled, mostly because the checks 415 1.9.2.2 skrll * have to be done separately from the return value. 416 1.9.2.2 skrll */ 417 1.9.2.2 skrll 418 1.9.2.2 skrll #if defined(DIAGNOSTIC) 419 1.9.2.2 skrll static inline 420 1.9.2.2 skrll struct tmpfs_mount * 421 1.9.2.2 skrll VFS_TO_TMPFS(struct mount *mp) 422 1.9.2.2 skrll { 423 1.9.2.2 skrll struct tmpfs_mount *tmp; 424 1.9.2.2 skrll 425 1.9.2.2 skrll KASSERT((mp) != NULL && (mp)->mnt_data != NULL); 426 1.9.2.2 skrll tmp = (struct tmpfs_mount *)(mp)->mnt_data; 427 1.9.2.2 skrll return tmp; 428 1.9.2.2 skrll } 429 1.9.2.2 skrll 430 1.9.2.2 skrll static inline 431 1.9.2.2 skrll struct tmpfs_node * 432 1.9.2.2 skrll VP_TO_TMPFS_NODE(struct vnode *vp) 433 1.9.2.2 skrll { 434 1.9.2.2 skrll struct tmpfs_node *node; 435 1.9.2.2 skrll 436 1.9.2.2 skrll KASSERT((vp) != NULL && (vp)->v_data != NULL); 437 1.9.2.2 skrll node = (struct tmpfs_node *)vp->v_data; 438 1.9.2.2 skrll return node; 439 1.9.2.2 skrll } 440 1.9.2.2 skrll 441 1.9.2.2 skrll static inline 442 1.9.2.2 skrll struct tmpfs_node * 443 1.9.2.2 skrll VP_TO_TMPFS_DIR(struct vnode *vp) 444 1.9.2.2 skrll { 445 1.9.2.2 skrll struct tmpfs_node *node; 446 1.9.2.2 skrll 447 1.9.2.2 skrll node = VP_TO_TMPFS_NODE(vp); 448 1.9.2.2 skrll TMPFS_VALIDATE_DIR(node); 449 1.9.2.2 skrll return node; 450 1.9.2.2 skrll } 451 1.9.2.2 skrll #else 452 1.9.2.2 skrll # define VFS_TO_TMPFS(mp) ((struct tmpfs_mount *)mp->mnt_data) 453 1.9.2.2 skrll # define VP_TO_TMPFS_NODE(vp) ((struct tmpfs_node *)vp->v_data) 454 1.9.2.2 skrll # define VP_TO_TMPFS_DIR(vp) VP_TO_TMPFS_NODE(vp) 455 1.9.2.2 skrll #endif 456 1.9.2.2 skrll 457 1.9.2.2 skrll #endif /* _KERNEL */ 458 1.9.2.2 skrll 459 1.9.2.2 skrll /* --------------------------------------------------------------------- 460 1.9.2.2 skrll * USER AND KERNEL DEFINITIONS 461 1.9.2.2 skrll * --------------------------------------------------------------------- */ 462 1.9.2.2 skrll 463 1.9.2.2 skrll /* 464 1.9.2.2 skrll * This structure is used to communicate mount parameters between userland 465 1.9.2.2 skrll * and kernel space. 466 1.9.2.2 skrll */ 467 1.9.2.2 skrll #define TMPFS_ARGS_VERSION 1 468 1.9.2.2 skrll struct tmpfs_args { 469 1.9.2.2 skrll int ta_version; 470 1.9.2.2 skrll 471 1.9.2.2 skrll /* Size counters. */ 472 1.9.2.2 skrll ino_t ta_nodes_max; 473 1.9.2.2 skrll off_t ta_size_max; 474 1.9.2.2 skrll 475 1.9.2.2 skrll /* Root node attributes. */ 476 1.9.2.2 skrll uid_t ta_root_uid; 477 1.9.2.2 skrll gid_t ta_root_gid; 478 1.9.2.2 skrll mode_t ta_root_mode; 479 1.9.2.2 skrll }; 480 1.9.2.4 christos #endif /* _FS_TMPFS_TMPFS_H_ */ 481
Indexes created Tue Sep 30 20:09:53 GMT 2025