tmpfs.h revision 1.9.2.2
1 1.9.2.2 skrll /* $NetBSD: tmpfs.h,v 1.9.2.2 2005/11/10 14:09:44 skrll 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 1.9.2.2 skrll #if !defined(_TMPFS_H_) 41 1.9.2.2 skrll # define _TMPFS_H_ 42 1.9.2.2 skrll #else 43 1.9.2.2 skrll # error "tmpfs.h cannot be included multiple times." 44 1.9.2.2 skrll #endif 45 1.9.2.2 skrll 46 1.9.2.2 skrll /* --------------------------------------------------------------------- 47 1.9.2.2 skrll * KERNEL-SPECIFIC DEFINITIONS 48 1.9.2.2 skrll * --------------------------------------------------------------------- */ 49 1.9.2.2 skrll 50 1.9.2.2 skrll #if defined(_KERNEL) 51 1.9.2.2 skrll 52 1.9.2.2 skrll #include <sys/dirent.h> 53 1.9.2.2 skrll #include <sys/mount.h> 54 1.9.2.2 skrll #include <sys/queue.h> 55 1.9.2.2 skrll #include <sys/vnode.h> 56 1.9.2.2 skrll 57 1.9.2.2 skrll #include <fs/tmpfs/tmpfs_pool.h> 58 1.9.2.2 skrll 59 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 60 1.9.2.2 skrll 61 1.9.2.2 skrll /* 62 1.9.2.2 skrll * Internal representation of a tmpfs directory entry. 63 1.9.2.2 skrll */ 64 1.9.2.2 skrll struct tmpfs_dirent { 65 1.9.2.2 skrll TAILQ_ENTRY(tmpfs_dirent) td_entries; 66 1.9.2.2 skrll 67 1.9.2.2 skrll /* Length of the name stored in this directory entry. This avoids 68 1.9.2.2 skrll * the need to recalculate it every time the name is used. */ 69 1.9.2.2 skrll uint16_t td_namelen; 70 1.9.2.2 skrll 71 1.9.2.2 skrll /* The name of the entry, allocated from a string pool. This 72 1.9.2.2 skrll * string is not required to be zero-terminated; therefore, the 73 1.9.2.2 skrll * td_namelen field must always be used when accessing its value. */ 74 1.9.2.2 skrll char * td_name; 75 1.9.2.2 skrll 76 1.9.2.2 skrll /* Pointer to the node this entry refers to. */ 77 1.9.2.2 skrll struct tmpfs_node * td_node; 78 1.9.2.2 skrll }; 79 1.9.2.2 skrll 80 1.9.2.2 skrll /* A directory in tmpfs holds a sorted list of directory entries, which in 81 1.9.2.2 skrll * turn point to other files (which can be directories themselves). 82 1.9.2.2 skrll * 83 1.9.2.2 skrll * In tmpfs, this list is managed by a tail queue, whose head is defined by 84 1.9.2.2 skrll * the struct tmpfs_dir type. 85 1.9.2.2 skrll * 86 1.9.2.2 skrll * It is imporant to notice that directories do not have entries for . and 87 1.9.2.2 skrll * .. as other file systems do. These can be generated when requested 88 1.9.2.2 skrll * based on information available by other means, such as the pointer to 89 1.9.2.2 skrll * the node itself in the former case or the pointer to the parent directory 90 1.9.2.2 skrll * in the latter case. This is done to simplify tmpfs's code and, more 91 1.9.2.2 skrll * importantly, to remove redundancy. */ 92 1.9.2.2 skrll TAILQ_HEAD(tmpfs_dir, tmpfs_dirent); 93 1.9.2.2 skrll 94 1.9.2.2 skrll #define TMPFS_DIRCOOKIE(dirent) ((off_t)(uintptr_t)(dirent)) 95 1.9.2.2 skrll #define TMPFS_DIRCOOKIE_DOT 0 96 1.9.2.2 skrll #define TMPFS_DIRCOOKIE_DOTDOT 1 97 1.9.2.2 skrll #define TMPFS_DIRCOOKIE_EOF 2 98 1.9.2.2 skrll 99 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 100 1.9.2.2 skrll 101 1.9.2.2 skrll /* 102 1.9.2.2 skrll * Internal representation of a tmpfs file system node. 103 1.9.2.2 skrll * 104 1.9.2.2 skrll * This structure is splitted in two parts: one holds attributes common 105 1.9.2.2 skrll * to all file types and the other holds data that is only applicable to 106 1.9.2.2 skrll * a particular type. The code must be careful to only access those 107 1.9.2.2 skrll * attributes that are actually allowed by the node's type. 108 1.9.2.2 skrll */ 109 1.9.2.2 skrll struct tmpfs_node { 110 1.9.2.2 skrll /* Doubly-linked list entry which links all existing nodes for a 111 1.9.2.2 skrll * single file system. This is provided to ease the removal of 112 1.9.2.2 skrll * all nodes during the unmount operation. */ 113 1.9.2.2 skrll LIST_ENTRY(tmpfs_node) tn_entries; 114 1.9.2.2 skrll 115 1.9.2.2 skrll /* The node's type. Any of 'VBLK', 'VCHR', 'VDIR', 'VFIFO', 116 1.9.2.2 skrll * 'VLNK', 'VREG' and 'VSOCK' is allowed. The usage of vnode 117 1.9.2.2 skrll * types instead of a custom enumeration is to make things simpler 118 1.9.2.2 skrll * and faster, as we do not need to convert between two types. */ 119 1.9.2.2 skrll enum vtype tn_type; 120 1.9.2.2 skrll 121 1.9.2.2 skrll /* Node identifier. */ 122 1.9.2.2 skrll ino_t tn_id; 123 1.9.2.2 skrll 124 1.9.2.2 skrll /* Node's internal status. This is used by several file system 125 1.9.2.2 skrll * operations to do modifications to the node in a delayed 126 1.9.2.2 skrll * fashion. */ 127 1.9.2.2 skrll int tn_status; 128 1.9.2.2 skrll #define TMPFS_NODE_ACCESSED (1 << 1) 129 1.9.2.2 skrll #define TMPFS_NODE_MODIFIED (1 << 2) 130 1.9.2.2 skrll #define TMPFS_NODE_CHANGED (1 << 3) 131 1.9.2.2 skrll 132 1.9.2.2 skrll /* The node size. It does not necessarily match the real amount 133 1.9.2.2 skrll * of memory consumed by it. */ 134 1.9.2.2 skrll off_t tn_size; 135 1.9.2.2 skrll 136 1.9.2.2 skrll /* Generic node attributes. */ 137 1.9.2.2 skrll uid_t tn_uid; 138 1.9.2.2 skrll gid_t tn_gid; 139 1.9.2.2 skrll mode_t tn_mode; 140 1.9.2.2 skrll int tn_flags; 141 1.9.2.2 skrll nlink_t tn_links; 142 1.9.2.2 skrll struct timespec tn_atime; 143 1.9.2.2 skrll struct timespec tn_mtime; 144 1.9.2.2 skrll struct timespec tn_ctime; 145 1.9.2.2 skrll struct timespec tn_birthtime; 146 1.9.2.2 skrll unsigned long tn_gen; 147 1.9.2.2 skrll 148 1.9.2.2 skrll /* Head of byte-level lock list (used by tmpfs_advlock). */ 149 1.9.2.2 skrll struct lockf * tn_lockf; 150 1.9.2.2 skrll 151 1.9.2.2 skrll /* As there is a single vnode for each active file within the 152 1.9.2.2 skrll * system, care has to be taken to avoid allocating more than one 153 1.9.2.2 skrll * vnode per file. In order to do this, a bidirectional association 154 1.9.2.2 skrll * is kept between vnodes and nodes. 155 1.9.2.2 skrll * 156 1.9.2.2 skrll * Whenever a vnode is allocated, its v_data field is updated to 157 1.9.2.2 skrll * point to the node it references. At the same time, the node's 158 1.9.2.2 skrll * tn_vnode field is modified to point to the new vnode representing 159 1.9.2.2 skrll * it. Further attempts to allocate a vnode for this same node will 160 1.9.2.2 skrll * result in returning a new reference to the value stored in 161 1.9.2.2 skrll * tn_vnode. 162 1.9.2.2 skrll * 163 1.9.2.2 skrll * May be NULL when the node is unused (that is, no vnode has been 164 1.9.2.2 skrll * allocated for it or it has been reclaimed). */ 165 1.9.2.2 skrll struct vnode * tn_vnode; 166 1.9.2.2 skrll 167 1.9.2.2 skrll /* Pointer to the node returned by tmpfs_lookup() after doing a 168 1.9.2.2 skrll * delete or a rename lookup; its value is only valid in these two 169 1.9.2.2 skrll * situations. In case we were looking up . or .., it holds a null 170 1.9.2.2 skrll * pointer. */ 171 1.9.2.2 skrll struct tmpfs_dirent * tn_lookup_dirent; 172 1.9.2.2 skrll 173 1.9.2.2 skrll union { 174 1.9.2.2 skrll /* Valid when tn_type == VBLK || tn_type == VCHR. */ 175 1.9.2.2 skrll struct { 176 1.9.2.2 skrll dev_t tn_rdev; 177 1.9.2.2 skrll }; 178 1.9.2.2 skrll 179 1.9.2.2 skrll /* Valid when tn_type == VDIR. */ 180 1.9.2.2 skrll struct { 181 1.9.2.2 skrll /* Pointer to the parent directory. The root 182 1.9.2.2 skrll * directory has a pointer to itself in this field; 183 1.9.2.2 skrll * this property identifies the root node. */ 184 1.9.2.2 skrll struct tmpfs_node * tn_parent; 185 1.9.2.2 skrll 186 1.9.2.2 skrll /* Head of a tail-queue that links the contents of 187 1.9.2.2 skrll * the directory together. See above for a 188 1.9.2.2 skrll * description of its contents. */ 189 1.9.2.2 skrll struct tmpfs_dir tn_dir; 190 1.9.2.2 skrll 191 1.9.2.2 skrll /* Number and pointer of the first directory entry 192 1.9.2.2 skrll * returned by the readdir operation if it were 193 1.9.2.2 skrll * called again to continue reading data from the 194 1.9.2.2 skrll * same directory as before. This is used to speed 195 1.9.2.2 skrll * up reads of long directories, assuming that no 196 1.9.2.2 skrll * more than one read is in progress at a given time. 197 1.9.2.2 skrll * Otherwise, these values are discarded and a linear 198 1.9.2.2 skrll * scan is performed from the beginning up to the 199 1.9.2.2 skrll * point where readdir starts returning values. */ 200 1.9.2.2 skrll off_t tn_readdir_lastn; 201 1.9.2.2 skrll struct tmpfs_dirent * tn_readdir_lastp; 202 1.9.2.2 skrll }; 203 1.9.2.2 skrll 204 1.9.2.2 skrll /* Valid when tn_type == VLNK. */ 205 1.9.2.2 skrll struct { 206 1.9.2.2 skrll /* The link's target, allocated from a string pool. */ 207 1.9.2.2 skrll char * tn_link; 208 1.9.2.2 skrll }; 209 1.9.2.2 skrll 210 1.9.2.2 skrll /* Valid when tn_type == VREG. */ 211 1.9.2.2 skrll struct { 212 1.9.2.2 skrll /* The contents of regular files stored in a tmpfs 213 1.9.2.2 skrll * file system are represented by a single anonymous 214 1.9.2.2 skrll * memory object (aobj, for short). The aobj provides 215 1.9.2.2 skrll * direct access to any position within the file, 216 1.9.2.2 skrll * because its contents are always mapped in a 217 1.9.2.2 skrll * contiguous region of virtual memory. It is a task 218 1.9.2.2 skrll * of the memory management subsystem (see uvm(9)) to 219 1.9.2.2 skrll * issue the required page ins or page outs whenever 220 1.9.2.2 skrll * a position within the file is accessed. */ 221 1.9.2.2 skrll struct uvm_object * tn_aobj; 222 1.9.2.2 skrll size_t tn_aobj_pages; 223 1.9.2.2 skrll }; 224 1.9.2.2 skrll }; 225 1.9.2.2 skrll }; 226 1.9.2.2 skrll LIST_HEAD(tmpfs_node_list, tmpfs_node); 227 1.9.2.2 skrll 228 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 229 1.9.2.2 skrll 230 1.9.2.2 skrll /* 231 1.9.2.2 skrll * Internal representation of a tmpfs mount point. 232 1.9.2.2 skrll */ 233 1.9.2.2 skrll struct tmpfs_mount { 234 1.9.2.2 skrll /* Maximum number of memory pages available for use by the file 235 1.9.2.2 skrll * system, set during mount time. This variable must never be 236 1.9.2.2 skrll * used directly as it may be bigger that the current amount of 237 1.9.2.2 skrll * free memory; in the extreme case, it will hold the SIZE_MAX 238 1.9.2.2 skrll * value. Instead, use the TMPFS_PAGES_MAX macro. */ 239 1.9.2.2 skrll size_t tm_pages_max; 240 1.9.2.2 skrll 241 1.9.2.2 skrll /* Number of pages in use by the file system. Cannot be bigger 242 1.9.2.2 skrll * than the value returned by TMPFS_PAGES_MAX in any case. */ 243 1.9.2.2 skrll size_t tm_pages_used; 244 1.9.2.2 skrll 245 1.9.2.2 skrll /* Pointer to the node representing the root directory of this 246 1.9.2.2 skrll * file system. */ 247 1.9.2.2 skrll struct tmpfs_node * tm_root; 248 1.9.2.2 skrll 249 1.9.2.2 skrll /* Maximum number of possible nodes for this file system; set 250 1.9.2.2 skrll * during mount time. We need a hard limit on the maximum number 251 1.9.2.2 skrll * of nodes to avoid allocating too much of them; their objects 252 1.9.2.2 skrll * cannot be released until the file system is unmounted. 253 1.9.2.2 skrll * Otherwise, we could easily run out of memory by creating lots 254 1.9.2.2 skrll * of empty files and then simply removing them. */ 255 1.9.2.2 skrll ino_t tm_nodes_max; 256 1.9.2.2 skrll 257 1.9.2.2 skrll /* Number of nodes currently allocated. This number only grows. 258 1.9.2.2 skrll * When it reaches tm_nodes_max, no more new nodes can be allocated. 259 1.9.2.2 skrll * Of course, the old, unused ones can be reused. */ 260 1.9.2.2 skrll ino_t tm_nodes_last; 261 1.9.2.2 skrll 262 1.9.2.2 skrll /* Nodes are organized in two different lists. The used list 263 1.9.2.2 skrll * contains all nodes that are currently used by the file system; 264 1.9.2.2 skrll * i.e., they refer to existing files. The available list contains 265 1.9.2.2 skrll * all nodes that are currently available for use by new files. 266 1.9.2.2 skrll * Nodes must be kept in this list (instead of deleting them) 267 1.9.2.2 skrll * because we need to keep track of their generation number (tn_gen 268 1.9.2.2 skrll * field). 269 1.9.2.2 skrll * 270 1.9.2.2 skrll * Note that nodes are lazily allocated: if the available list is 271 1.9.2.2 skrll * empty and we have enough space to create more nodes, they will be 272 1.9.2.2 skrll * created and inserted in the used list. Once these are released, 273 1.9.2.2 skrll * they will go into the available list, remaining alive until the 274 1.9.2.2 skrll * file system is unmounted. */ 275 1.9.2.2 skrll struct tmpfs_node_list tm_nodes_used; 276 1.9.2.2 skrll struct tmpfs_node_list tm_nodes_avail; 277 1.9.2.2 skrll 278 1.9.2.2 skrll /* Pools used to store file system meta data. These are not shared 279 1.9.2.2 skrll * across several instances of tmpfs for the reasons described in 280 1.9.2.2 skrll * tmpfs_pool.c. */ 281 1.9.2.2 skrll struct tmpfs_pool tm_dirent_pool; 282 1.9.2.2 skrll struct tmpfs_pool tm_node_pool; 283 1.9.2.2 skrll struct tmpfs_str_pool tm_str_pool; 284 1.9.2.2 skrll }; 285 1.9.2.2 skrll 286 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 287 1.9.2.2 skrll 288 1.9.2.2 skrll /* 289 1.9.2.2 skrll * This structure maps a file identifier to a tmpfs node. Used by the 290 1.9.2.2 skrll * NFS code. 291 1.9.2.2 skrll */ 292 1.9.2.2 skrll struct tmpfs_fid { 293 1.9.2.2 skrll uint16_t tf_len; 294 1.9.2.2 skrll uint16_t tf_pad; 295 1.9.2.2 skrll ino_t tf_id; 296 1.9.2.2 skrll unsigned long tf_gen; 297 1.9.2.2 skrll }; 298 1.9.2.2 skrll 299 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 300 1.9.2.2 skrll 301 1.9.2.2 skrll /* 302 1.9.2.2 skrll * Prototypes for tmpfs_subr.c. 303 1.9.2.2 skrll */ 304 1.9.2.2 skrll 305 1.9.2.2 skrll int tmpfs_alloc_node(struct tmpfs_mount *, enum vtype, 306 1.9.2.2 skrll uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *, 307 1.9.2.2 skrll char *, dev_t, struct proc *, struct tmpfs_node **); 308 1.9.2.2 skrll void tmpfs_free_node(struct tmpfs_mount *, struct tmpfs_node *); 309 1.9.2.2 skrll int tmpfs_alloc_dirent(struct tmpfs_mount *, struct tmpfs_node *, 310 1.9.2.2 skrll const char *, uint16_t, struct tmpfs_dirent **); 311 1.9.2.2 skrll void tmpfs_free_dirent(struct tmpfs_mount *, struct tmpfs_dirent *, 312 1.9.2.2 skrll boolean_t); 313 1.9.2.2 skrll int tmpfs_alloc_vp(struct mount *, struct tmpfs_node *, struct vnode **); 314 1.9.2.2 skrll void tmpfs_free_vp(struct vnode *); 315 1.9.2.2 skrll int tmpfs_alloc_file(struct vnode *, struct vnode **, struct vattr *, 316 1.9.2.2 skrll struct componentname *, char *); 317 1.9.2.2 skrll void tmpfs_dir_attach(struct vnode *, struct tmpfs_dirent *); 318 1.9.2.2 skrll void tmpfs_dir_detach(struct vnode *, struct tmpfs_dirent *); 319 1.9.2.2 skrll struct tmpfs_dirent * tmpfs_dir_lookup(struct tmpfs_node *node, 320 1.9.2.2 skrll struct componentname *cnp); 321 1.9.2.2 skrll int tmpfs_dir_getdotdent(struct tmpfs_node *, struct uio *); 322 1.9.2.2 skrll int tmpfs_dir_getdotdotdent(struct tmpfs_node *, struct uio *); 323 1.9.2.2 skrll struct tmpfs_dirent * tmpfs_dir_lookupbycookie(struct tmpfs_node *, off_t); 324 1.9.2.2 skrll int tmpfs_dir_getdents(struct tmpfs_node *, struct uio *, off_t *); 325 1.9.2.2 skrll int tmpfs_reg_resize(struct vnode *, off_t); 326 1.9.2.2 skrll size_t tmpfs_mem_info(boolean_t); 327 1.9.2.2 skrll int tmpfs_chflags(struct vnode *, int, struct ucred *, struct proc *); 328 1.9.2.2 skrll int tmpfs_chmod(struct vnode *, mode_t, struct ucred *, struct proc *); 329 1.9.2.2 skrll int tmpfs_chown(struct vnode *, uid_t, gid_t, struct ucred *, 330 1.9.2.2 skrll struct proc *); 331 1.9.2.2 skrll int tmpfs_chsize(struct vnode *, u_quad_t, struct ucred *, struct proc *); 332 1.9.2.2 skrll int tmpfs_chtimes(struct vnode *, struct timespec *, struct timespec *, 333 1.9.2.2 skrll int, struct ucred *, struct proc *); 334 1.9.2.2 skrll void tmpfs_itimes(struct vnode *, const struct timespec *, 335 1.9.2.2 skrll const struct timespec *); 336 1.9.2.2 skrll 337 1.9.2.2 skrll void tmpfs_update(struct vnode *, const struct timespec *, 338 1.9.2.2 skrll const struct timespec *, int); 339 1.9.2.2 skrll int tmpfs_truncate(struct vnode *, off_t); 340 1.9.2.2 skrll 341 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 342 1.9.2.2 skrll 343 1.9.2.2 skrll /* 344 1.9.2.2 skrll * Convenience macros to simplify some logical expressions. 345 1.9.2.2 skrll */ 346 1.9.2.2 skrll #define IMPLIES(a, b) (!(a) || (b)) 347 1.9.2.2 skrll #define IFF(a, b) (IMPLIES(a, b) && IMPLIES(b, a)) 348 1.9.2.2 skrll 349 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 350 1.9.2.2 skrll 351 1.9.2.2 skrll /* 352 1.9.2.2 skrll * Checks that the directory entry pointed by 'de' matches the name 'name' 353 1.9.2.2 skrll * with a length of 'len'. 354 1.9.2.2 skrll */ 355 1.9.2.2 skrll #define TMPFS_DIRENT_MATCHES(de, name, len) \ 356 1.9.2.2 skrll (de->td_namelen == (uint16_t)len && \ 357 1.9.2.2 skrll memcmp((de)->td_name, (name), (de)->td_namelen) == 0) 358 1.9.2.2 skrll 359 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 360 1.9.2.2 skrll 361 1.9.2.2 skrll /* 362 1.9.2.2 skrll * Ensures that the node pointed by 'node' is a directory and that its 363 1.9.2.2 skrll * contents are consistent with respect to directories. 364 1.9.2.2 skrll */ 365 1.9.2.2 skrll #define TMPFS_VALIDATE_DIR(node) \ 366 1.9.2.2 skrll KASSERT((node)->tn_type == VDIR); \ 367 1.9.2.2 skrll KASSERT((node)->tn_size % sizeof(struct tmpfs_dirent) == 0); \ 368 1.9.2.2 skrll KASSERT((node)->tn_readdir_lastp == NULL || \ 369 1.9.2.2 skrll TMPFS_DIRCOOKIE((node)->tn_readdir_lastp) == (node)->tn_readdir_lastn); 370 1.9.2.2 skrll 371 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 372 1.9.2.2 skrll 373 1.9.2.2 skrll /* 374 1.9.2.2 skrll * Memory management stuff. 375 1.9.2.2 skrll */ 376 1.9.2.2 skrll 377 1.9.2.2 skrll /* Amount of memory pages to reserve for the system (e.g., to not use by 378 1.9.2.2 skrll * tmpfs). 379 1.9.2.2 skrll * XXX: Should this be tunable through sysctl, for instance? */ 380 1.9.2.2 skrll #define TMPFS_PAGES_RESERVED (4 * 1024 * 1024 / PAGE_SIZE) 381 1.9.2.2 skrll 382 1.9.2.2 skrll /* Returns the maximum size allowed for a tmpfs file system. This macro 383 1.9.2.2 skrll * must be used instead of directly retrieving the value from tm_pages_max. 384 1.9.2.2 skrll * The reason is that the size of a tmpfs file system is dynamic: it lets 385 1.9.2.2 skrll * the user store files as long as there is enough free memory (including 386 1.9.2.2 skrll * physical memory and swap space). Therefore, the amount of memory to be 387 1.9.2.2 skrll * used is either the limit imposed by the user during mount time or the 388 1.9.2.2 skrll * amount of available memory, whichever is lower. To avoid consuming all 389 1.9.2.2 skrll * the memory for a given mount point, the system will always reserve a 390 1.9.2.2 skrll * minimum of TMPFS_PAGES_RESERVED pages, which is also taken into account 391 1.9.2.2 skrll * by this macro (see above). */ 392 1.9.2.2 skrll static inline size_t 393 1.9.2.2 skrll TMPFS_PAGES_MAX(struct tmpfs_mount *tmp) 394 1.9.2.2 skrll { 395 1.9.2.2 skrll size_t freepages; 396 1.9.2.2 skrll 397 1.9.2.2 skrll freepages = tmpfs_mem_info(FALSE); 398 1.9.2.2 skrll if (freepages < TMPFS_PAGES_RESERVED) 399 1.9.2.2 skrll freepages = 0; 400 1.9.2.2 skrll else 401 1.9.2.2 skrll freepages -= TMPFS_PAGES_RESERVED; 402 1.9.2.2 skrll 403 1.9.2.2 skrll return MIN(tmp->tm_pages_max, freepages + tmp->tm_pages_used); 404 1.9.2.2 skrll } 405 1.9.2.2 skrll 406 1.9.2.2 skrll /* Returns the available space for the given file system. */ 407 1.9.2.2 skrll #define TMPFS_PAGES_AVAIL(tmp) (TMPFS_PAGES_MAX(tmp) - (tmp)->tm_pages_used) 408 1.9.2.2 skrll 409 1.9.2.2 skrll /* --------------------------------------------------------------------- */ 410 1.9.2.2 skrll 411 1.9.2.2 skrll /* 412 1.9.2.2 skrll * Macros/functions to convert from generic data structures to tmpfs 413 1.9.2.2 skrll * specific ones. 414 1.9.2.2 skrll * 415 1.9.2.2 skrll * Macros are used when no sanity checks have to be done, as they provide 416 1.9.2.2 skrll * the fastest conversion. On the other hand, inlined functions are used 417 1.9.2.2 skrll * when expensive sanity checks are enabled, mostly because the checks 418 1.9.2.2 skrll * have to be done separately from the return value. 419 1.9.2.2 skrll */ 420 1.9.2.2 skrll 421 1.9.2.2 skrll #if defined(DIAGNOSTIC) 422 1.9.2.2 skrll static inline 423 1.9.2.2 skrll struct tmpfs_mount * 424 1.9.2.2 skrll VFS_TO_TMPFS(struct mount *mp) 425 1.9.2.2 skrll { 426 1.9.2.2 skrll struct tmpfs_mount *tmp; 427 1.9.2.2 skrll 428 1.9.2.2 skrll KASSERT((mp) != NULL && (mp)->mnt_data != NULL); 429 1.9.2.2 skrll tmp = (struct tmpfs_mount *)(mp)->mnt_data; 430 1.9.2.2 skrll KASSERT(TMPFS_PAGES_MAX(tmp) >= tmp->tm_pages_used); 431 1.9.2.2 skrll return tmp; 432 1.9.2.2 skrll } 433 1.9.2.2 skrll 434 1.9.2.2 skrll static inline 435 1.9.2.2 skrll struct tmpfs_node * 436 1.9.2.2 skrll VP_TO_TMPFS_NODE(struct vnode *vp) 437 1.9.2.2 skrll { 438 1.9.2.2 skrll struct tmpfs_node *node; 439 1.9.2.2 skrll 440 1.9.2.2 skrll KASSERT((vp) != NULL && (vp)->v_data != NULL); 441 1.9.2.2 skrll node = (struct tmpfs_node *)vp->v_data; 442 1.9.2.2 skrll return node; 443 1.9.2.2 skrll } 444 1.9.2.2 skrll 445 1.9.2.2 skrll static inline 446 1.9.2.2 skrll struct tmpfs_node * 447 1.9.2.2 skrll VP_TO_TMPFS_DIR(struct vnode *vp) 448 1.9.2.2 skrll { 449 1.9.2.2 skrll struct tmpfs_node *node; 450 1.9.2.2 skrll 451 1.9.2.2 skrll node = VP_TO_TMPFS_NODE(vp); 452 1.9.2.2 skrll TMPFS_VALIDATE_DIR(node); 453 1.9.2.2 skrll return node; 454 1.9.2.2 skrll } 455 1.9.2.2 skrll #else 456 1.9.2.2 skrll # define VFS_TO_TMPFS(mp) ((struct tmpfs_mount *)mp->mnt_data) 457 1.9.2.2 skrll # define VP_TO_TMPFS_NODE(vp) ((struct tmpfs_node *)vp->v_data) 458 1.9.2.2 skrll # define VP_TO_TMPFS_DIR(vp) VP_TO_TMPFS_NODE(vp) 459 1.9.2.2 skrll #endif 460 1.9.2.2 skrll 461 1.9.2.2 skrll #endif /* _KERNEL */ 462 1.9.2.2 skrll 463 1.9.2.2 skrll /* --------------------------------------------------------------------- 464 1.9.2.2 skrll * USER AND KERNEL DEFINITIONS 465 1.9.2.2 skrll * --------------------------------------------------------------------- */ 466 1.9.2.2 skrll 467 1.9.2.2 skrll /* 468 1.9.2.2 skrll * This structure is used to communicate mount parameters between userland 469 1.9.2.2 skrll * and kernel space. 470 1.9.2.2 skrll */ 471 1.9.2.2 skrll #define TMPFS_ARGS_VERSION 1 472 1.9.2.2 skrll struct tmpfs_args { 473 1.9.2.2 skrll int ta_version; 474 1.9.2.2 skrll 475 1.9.2.2 skrll /* Size counters. */ 476 1.9.2.2 skrll ino_t ta_nodes_max; 477 1.9.2.2 skrll off_t ta_size_max; 478 1.9.2.2 skrll 479 1.9.2.2 skrll /* Root node attributes. */ 480 1.9.2.2 skrll uid_t ta_root_uid; 481 1.9.2.2 skrll gid_t ta_root_gid; 482 1.9.2.2 skrll mode_t ta_root_mode; 483 1.9.2.2 skrll }; 484
Indexes created Tue Sep 30 20:09:53 GMT 2025