| 1 | /* $NetBSD: tmpfs.h,v 1.52 2015/07/06 10:07:12 hannken Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 2005, 2006, 2007 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to The NetBSD Foundation |
| 8 | * by Julio M. Merino Vidal, developed as part of Google's Summer of Code |
| 9 | * 2005 program. |
| 10 | * |
| 11 | * Redistribution and use in source and binary forms, with or without |
| 12 | * modification, are permitted provided that the following conditions |
| 13 | * are met: |
| 14 | * 1. Redistributions of source code must retain the above copyright |
| 15 | * notice, this list of conditions and the following disclaimer. |
| 16 | * 2. Redistributions in binary form must reproduce the above copyright |
| 17 | * notice, this list of conditions and the following disclaimer in the |
| 18 | * documentation and/or other materials provided with the distribution. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 21 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 22 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 23 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 24 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 25 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 26 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 27 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 28 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 29 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 30 | * POSSIBILITY OF SUCH DAMAGE. |
| 31 | */ |
| 32 | |
| 33 | #ifndef _FS_TMPFS_TMPFS_H_ |
| 34 | #define _FS_TMPFS_TMPFS_H_ |
| 35 | |
| 36 | #if !defined(_KERNEL) && !defined(_KMEMUSER) |
| 37 | #error "not supposed to be exposed to userland" |
| 38 | #endif |
| 39 | |
| 40 | #include <sys/dirent.h> |
| 41 | #include <sys/mount.h> |
| 42 | #include <sys/pool.h> |
| 43 | #include <sys/queue.h> |
| 44 | #include <sys/vnode.h> |
| 45 | |
| 46 | /* |
| 47 | * Internal representation of a tmpfs directory entry. |
| 48 | * |
| 49 | * All fields are protected by vnode lock. |
| 50 | */ |
| 51 | typedef struct tmpfs_dirent { |
| 52 | TAILQ_ENTRY(tmpfs_dirent) td_entries; |
| 53 | |
| 54 | /* Pointer to the inode this entry refers to. */ |
| 55 | struct tmpfs_node * td_node; |
| 56 | |
| 57 | /* Sequence number, see tmpfs_dir_getseq(). */ |
| 58 | uint32_t td_seq; |
| 59 | |
| 60 | /* Name and its length. */ |
| 61 | char * td_name; |
| 62 | uint16_t td_namelen; |
| 63 | } tmpfs_dirent_t; |
| 64 | |
| 65 | TAILQ_HEAD(tmpfs_dir, tmpfs_dirent); |
| 66 | |
| 67 | /* |
| 68 | * Internal representation of a tmpfs file system node -- inode. |
| 69 | * |
| 70 | * This structure is split in two parts: one holds attributes common |
| 71 | * to all file types and the other holds data that is only applicable to |
| 72 | * a particular type. |
| 73 | * |
| 74 | * All fields are protected by vnode lock. The vnode association itself |
| 75 | * is protected by vcache. |
| 76 | */ |
| 77 | typedef struct tmpfs_node { |
| 78 | LIST_ENTRY(tmpfs_node) tn_entries; |
| 79 | |
| 80 | /* |
| 81 | * Each inode has a corresponding vnode. It is a bi-directional |
| 82 | * association. Whenever vnode is allocated, its v_data field is |
| 83 | * set to the inode it reference, and tmpfs_node_t::tn_vnode is |
| 84 | * set to point to the said vnode. |
| 85 | * |
| 86 | * Further attempts to allocate a vnode for this same node will |
| 87 | * result in returning a new reference to the value stored in |
| 88 | * tn_vnode. It may be NULL when the node is unused (that is, |
| 89 | * no vnode has been allocated or it has been reclaimed). |
| 90 | */ |
| 91 | vnode_t * tn_vnode; |
| 92 | |
| 93 | /* Prevent node from being reclaimed. */ |
| 94 | uint32_t tn_holdcount; |
| 95 | |
| 96 | /* Directory entry. Only a hint, since hard link can have multiple. */ |
| 97 | tmpfs_dirent_t * tn_dirent_hint; |
| 98 | |
| 99 | /* The inode type: VBLK, VCHR, VDIR, VFIFO, VLNK, VREG or VSOCK. */ |
| 100 | enum vtype tn_type; |
| 101 | |
| 102 | /* Inode identifier and generation number. */ |
| 103 | ino_t tn_id; |
| 104 | uint32_t tn_gen; |
| 105 | |
| 106 | /* The inode size. */ |
| 107 | off_t tn_size; |
| 108 | |
| 109 | /* Generic node attributes. */ |
| 110 | uid_t tn_uid; |
| 111 | gid_t tn_gid; |
| 112 | mode_t tn_mode; |
| 113 | int tn_flags; |
| 114 | nlink_t tn_links; |
| 115 | struct timespec tn_atime; |
| 116 | struct timespec tn_mtime; |
| 117 | struct timespec tn_ctime; |
| 118 | struct timespec tn_birthtime; |
| 119 | |
| 120 | /* Head of byte-level lock list (used by tmpfs_advlock). */ |
| 121 | struct lockf * tn_lockf; |
| 122 | |
| 123 | union { |
| 124 | /* Type case: VBLK or VCHR. */ |
| 125 | struct { |
| 126 | dev_t tn_rdev; |
| 127 | } tn_dev; |
| 128 | |
| 129 | /* Type case: VDIR. */ |
| 130 | struct { |
| 131 | /* Parent directory (root inode points to itself). */ |
| 132 | struct tmpfs_node * tn_parent; |
| 133 | |
| 134 | /* List of directory entries. */ |
| 135 | struct tmpfs_dir tn_dir; |
| 136 | |
| 137 | /* Last given sequence number and their arena. */ |
| 138 | uint32_t tn_next_seq; |
| 139 | void * tn_seq_arena; |
| 140 | |
| 141 | /* |
| 142 | * Pointer of the last directory entry returned |
| 143 | * by the readdir(3) operation. |
| 144 | */ |
| 145 | struct tmpfs_dirent * tn_readdir_lastp; |
| 146 | } tn_dir; |
| 147 | |
| 148 | /* Type case: VLNK. */ |
| 149 | struct tn_lnk { |
| 150 | /* The link's target. */ |
| 151 | char * tn_link; |
| 152 | } tn_lnk; |
| 153 | |
| 154 | /* Type case: VREG. */ |
| 155 | struct tn_reg { |
| 156 | /* Underlying UVM object to store contents. */ |
| 157 | struct uvm_object * tn_aobj; |
| 158 | size_t tn_aobj_pages; |
| 159 | } tn_reg; |
| 160 | } tn_spec; |
| 161 | } tmpfs_node_t; |
| 162 | |
| 163 | #if defined(_KERNEL) |
| 164 | |
| 165 | VFS_PROTOS(tmpfs); |
| 166 | |
| 167 | LIST_HEAD(tmpfs_node_list, tmpfs_node); |
| 168 | |
| 169 | #define TMPFS_MAXNAMLEN 255 |
| 170 | /* Validate maximum td_namelen length. */ |
| 171 | CTASSERT(TMPFS_MAXNAMLEN < UINT16_MAX); |
| 172 | |
| 173 | /* |
| 174 | * Reserved values for the virtual entries (the first must be 0) and EOF. |
| 175 | * The start/end of the incremental range, see tmpfs_dir_getseq(). |
| 176 | */ |
| 177 | #define TMPFS_DIRSEQ_DOT 0 |
| 178 | #define TMPFS_DIRSEQ_DOTDOT 1 |
| 179 | #define TMPFS_DIRSEQ_EOF 2 |
| 180 | |
| 181 | #define TMPFS_DIRSEQ_START 3 /* inclusive */ |
| 182 | #define TMPFS_DIRSEQ_END (1U << 30) /* exclusive */ |
| 183 | |
| 184 | /* Mark to indicate that the number is not set. */ |
| 185 | #define TMPFS_DIRSEQ_NONE (1U << 31) |
| 186 | |
| 187 | /* Flags: time update requests. */ |
| 188 | #define TMPFS_UPDATE_ATIME 0x01 |
| 189 | #define TMPFS_UPDATE_MTIME 0x02 |
| 190 | #define TMPFS_UPDATE_CTIME 0x04 |
| 191 | |
| 192 | /* |
| 193 | * Bits indicating whiteout use for the directory. |
| 194 | * We abuse tmpfs_node_t::tn_gen for that. |
| 195 | */ |
| 196 | #define TMPFS_WHITEOUT_BIT (1U << 31) |
| 197 | #define TMPFS_NODE_GEN_MASK (TMPFS_WHITEOUT_BIT - 1) |
| 198 | |
| 199 | #define TMPFS_NODE_GEN(node) \ |
| 200 | ((node)->tn_gen & TMPFS_NODE_GEN_MASK) |
| 201 | |
| 202 | /* White-out inode indicator. */ |
| 203 | #define TMPFS_NODE_WHITEOUT ((tmpfs_node_t *)-1) |
| 204 | |
| 205 | /* |
| 206 | * Bit indicating this node must be reclaimed when holdcount reaches zero. |
| 207 | * Ored into tmpfs_node_t::tn_holdcount. |
| 208 | */ |
| 209 | #define TMPFS_NODE_RECLAIMED (1U << 30) |
| 210 | |
| 211 | /* |
| 212 | * Internal representation of a tmpfs mount point. |
| 213 | */ |
| 214 | typedef struct tmpfs_mount { |
| 215 | /* Limit and number of bytes in use by the file system. */ |
| 216 | uint64_t tm_mem_limit; |
| 217 | uint64_t tm_bytes_used; |
| 218 | kmutex_t tm_acc_lock; |
| 219 | |
| 220 | /* Pointer to the root inode. */ |
| 221 | tmpfs_node_t * tm_root; |
| 222 | |
| 223 | /* Maximum number of possible nodes for this file system. */ |
| 224 | unsigned int tm_nodes_max; |
| 225 | |
| 226 | /* Number of nodes currently allocated. */ |
| 227 | unsigned int tm_nodes_cnt; |
| 228 | |
| 229 | /* List of inodes and the lock protecting it. */ |
| 230 | kmutex_t tm_lock; |
| 231 | struct tmpfs_node_list tm_nodes; |
| 232 | } tmpfs_mount_t; |
| 233 | |
| 234 | /* |
| 235 | * This structure maps a file identifier to a tmpfs node. Used by the |
| 236 | * NFS code. |
| 237 | */ |
| 238 | typedef struct tmpfs_fid { |
| 239 | uint16_t tf_len; |
| 240 | uint16_t tf_pad; |
| 241 | uint32_t tf_gen; |
| 242 | ino_t tf_id; |
| 243 | } tmpfs_fid_t; |
| 244 | |
| 245 | /* |
| 246 | * Prototypes for tmpfs_subr.c. |
| 247 | */ |
| 248 | |
| 249 | void tmpfs_free_node(tmpfs_mount_t *, tmpfs_node_t *); |
| 250 | |
| 251 | int tmpfs_construct_node(vnode_t *, vnode_t **, struct vattr *, |
| 252 | struct componentname *, char *); |
| 253 | |
| 254 | int tmpfs_alloc_dirent(tmpfs_mount_t *, const char *, uint16_t, |
| 255 | tmpfs_dirent_t **); |
| 256 | void tmpfs_free_dirent(tmpfs_mount_t *, tmpfs_dirent_t *); |
| 257 | void tmpfs_dir_attach(tmpfs_node_t *, tmpfs_dirent_t *, tmpfs_node_t *); |
| 258 | void tmpfs_dir_detach(tmpfs_node_t *, tmpfs_dirent_t *); |
| 259 | |
| 260 | tmpfs_dirent_t *tmpfs_dir_lookup(tmpfs_node_t *, struct componentname *); |
| 261 | tmpfs_dirent_t *tmpfs_dir_cached(tmpfs_node_t *); |
| 262 | |
| 263 | uint32_t tmpfs_dir_getseq(tmpfs_node_t *, tmpfs_dirent_t *); |
| 264 | tmpfs_dirent_t *tmpfs_dir_lookupbyseq(tmpfs_node_t *, off_t); |
| 265 | int tmpfs_dir_getdents(tmpfs_node_t *, struct uio *, off_t *); |
| 266 | |
| 267 | int tmpfs_reg_resize(vnode_t *, off_t); |
| 268 | |
| 269 | int tmpfs_chflags(vnode_t *, int, kauth_cred_t, lwp_t *); |
| 270 | int tmpfs_chmod(vnode_t *, mode_t, kauth_cred_t, lwp_t *); |
| 271 | int tmpfs_chown(vnode_t *, uid_t, gid_t, kauth_cred_t, lwp_t *); |
| 272 | int tmpfs_chsize(vnode_t *, u_quad_t, kauth_cred_t, lwp_t *); |
| 273 | int tmpfs_chtimes(vnode_t *, const struct timespec *, |
| 274 | const struct timespec *, const struct timespec *, int, |
| 275 | kauth_cred_t, lwp_t *); |
| 276 | void tmpfs_update(vnode_t *, unsigned); |
| 277 | |
| 278 | /* |
| 279 | * Prototypes for tmpfs_mem.c. |
| 280 | */ |
| 281 | |
| 282 | void tmpfs_mntmem_init(tmpfs_mount_t *, uint64_t); |
| 283 | void tmpfs_mntmem_destroy(tmpfs_mount_t *); |
| 284 | int tmpfs_mntmem_set(tmpfs_mount_t *, uint64_t); |
| 285 | |
| 286 | size_t tmpfs_mem_info(bool); |
| 287 | uint64_t tmpfs_bytes_max(tmpfs_mount_t *); |
| 288 | size_t tmpfs_pages_avail(tmpfs_mount_t *); |
| 289 | bool tmpfs_mem_incr(tmpfs_mount_t *, size_t); |
| 290 | void tmpfs_mem_decr(tmpfs_mount_t *, size_t); |
| 291 | |
| 292 | tmpfs_dirent_t *tmpfs_dirent_get(tmpfs_mount_t *); |
| 293 | void tmpfs_dirent_put(tmpfs_mount_t *, tmpfs_dirent_t *); |
| 294 | |
| 295 | tmpfs_node_t * tmpfs_node_get(tmpfs_mount_t *); |
| 296 | void tmpfs_node_put(tmpfs_mount_t *, tmpfs_node_t *); |
| 297 | |
| 298 | char * tmpfs_strname_alloc(tmpfs_mount_t *, size_t); |
| 299 | void tmpfs_strname_free(tmpfs_mount_t *, char *, size_t); |
| 300 | bool tmpfs_strname_neqlen(struct componentname *, struct componentname *); |
| 301 | |
| 302 | /* |
| 303 | * Ensures that the node pointed by 'node' is a directory and that its |
| 304 | * contents are consistent with respect to directories. |
| 305 | */ |
| 306 | #define TMPFS_VALIDATE_DIR(node) \ |
| 307 | KASSERT((node)->tn_vnode == NULL || VOP_ISLOCKED((node)->tn_vnode)); \ |
| 308 | KASSERT((node)->tn_type == VDIR); \ |
| 309 | KASSERT((node)->tn_size % sizeof(tmpfs_dirent_t) == 0); |
| 310 | |
| 311 | /* |
| 312 | * Routines to convert VFS structures to tmpfs internal ones. |
| 313 | */ |
| 314 | |
| 315 | static inline tmpfs_mount_t * |
| 316 | VFS_TO_TMPFS(struct mount *mp) |
| 317 | { |
| 318 | tmpfs_mount_t *tmp = mp->mnt_data; |
| 319 | |
| 320 | KASSERT(tmp != NULL); |
| 321 | return tmp; |
| 322 | } |
| 323 | |
| 324 | static inline tmpfs_node_t * |
| 325 | VP_TO_TMPFS_DIR(vnode_t *vp) |
| 326 | { |
| 327 | tmpfs_node_t *node = vp->v_data; |
| 328 | |
| 329 | KASSERT(node != NULL); |
| 330 | TMPFS_VALIDATE_DIR(node); |
| 331 | return node; |
| 332 | } |
| 333 | |
| 334 | #endif /* defined(_KERNEL) */ |
| 335 | |
| 336 | static __inline tmpfs_node_t * |
| 337 | VP_TO_TMPFS_NODE(vnode_t *vp) |
| 338 | { |
| 339 | tmpfs_node_t *node = vp->v_data; |
| 340 | #ifdef KASSERT |
| 341 | KASSERT(node != NULL); |
| 342 | #endif |
| 343 | return node; |
| 344 | } |
| 345 | |
| 346 | #endif /* _FS_TMPFS_TMPFS_H_ */ |
| 347 | |