1 /* 2 * Copyright (c) 2013 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Antonio Huete Jimenez <tuxillo@quantumachine.net> 6 * by Matthew Dillon <dillon@dragonflybsd.org> 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in 16 * the documentation and/or other materials provided with the 17 * distribution. 18 * 3. Neither the name of The DragonFly Project nor the names of its 19 * contributors may be used to endorse or promote products derived 20 * from this software without specific, prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 30 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 */ 36 37 #include <sys/vfsops.h> 38 #include <sys/mount.h> 39 #include <sys/types.h> 40 #include <sys/systm.h> 41 #include <sys/param.h> 42 #include <sys/module.h> 43 #include <sys/kernel.h> 44 #include <sys/malloc.h> 45 #include <sys/sysctl.h> 46 #include <sys/queue.h> 47 #include <sys/spinlock2.h> 48 #include <sys/sysref2.h> 49 #include <sys/ktr.h> 50 51 #include <string.h> 52 53 #include "dirfs.h" 54 55 MALLOC_DEFINE(M_DIRFS, "dirfs", "dirfs mount allocation"); 56 MALLOC_DEFINE(M_DIRFS_NODE, "dirfs nodes", "dirfs nodes memory allocation"); 57 MALLOC_DEFINE(M_DIRFS_MISC, "dirfs misc", "dirfs miscellaneous allocation"); 58 59 /* 60 * Kernel tracing facilities 61 */ 62 KTR_INFO_MASTER(dirfs); 63 64 KTR_INFO(KTR_DIRFS, dirfs, root, 20, 65 "DIRFS(root dnp=%p vnode=%p hostdir=%s fd=%d error=%d)", 66 dirfs_node_t dnp, struct vnode *vp, char *hostdir, int fd, int error); 67 68 KTR_INFO(KTR_DIRFS, dirfs, mount, 21, 69 "DIRFS(mount path=%s dmp=%p mp=%p error=%d)", 70 char *path, dirfs_mount_t dmp, struct mount *mp, int error); 71 72 KTR_INFO(KTR_DIRFS, dirfs, unmount, 22, 73 "DIRFS(unmount dmp=%p mp=%p error=%d)", 74 dirfs_mount_t dmp, struct mount *mp, int error); 75 76 /* System wide sysctl stuff */ 77 int debuglvl = 0; 78 int dirfs_fd_limit = 100; 79 int dirfs_fd_used = 0; 80 long passive_fd_list_miss = 0; 81 long passive_fd_list_hits = 0; 82 83 SYSCTL_NODE(_vfs, OID_AUTO, dirfs, CTLFLAG_RW, 0, 84 "dirfs filesystem for vkernels"); 85 SYSCTL_INT(_vfs_dirfs, OID_AUTO, debug, CTLFLAG_RW, 86 &debuglvl, 0, "dirfs debug level"); 87 SYSCTL_INT(_vfs_dirfs, OID_AUTO, fd_limit, CTLFLAG_RW, 88 &dirfs_fd_limit, 0, "Maximum number of passive nodes to cache"); 89 SYSCTL_INT(_vfs_dirfs, OID_AUTO, fd_used, CTLFLAG_RD, 90 &dirfs_fd_used, 0, "Current number of passive nodes cached"); 91 SYSCTL_LONG(_vfs_dirfs, OID_AUTO, passive_fd_list_miss, CTLFLAG_RD, 92 &passive_fd_list_miss, 0, "Passive fd list cache misses"); 93 SYSCTL_LONG(_vfs_dirfs, OID_AUTO, passive_fd_list_hits, CTLFLAG_RD, 94 &passive_fd_list_hits, 0, "Passive fd list cache misses"); 95 96 static int dirfs_statfs(struct mount *, struct statfs *, struct ucred *); 97 98 static int 99 dirfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred) 100 { 101 dirfs_mount_t dmp; 102 struct stat st; 103 size_t done, nlen; 104 int error; 105 106 debug_called(); 107 108 if (mp->mnt_flag & MNT_UPDATE) { 109 dmp = VFS_TO_DIRFS(mp); 110 if (dmp->dm_rdonly == 0 && (mp->mnt_flag & MNT_RDONLY)) { 111 /* XXX We should make sure all writes are synced */ 112 dmp->dm_rdonly = 1; 113 debug(2, "dirfs read-write -> read-only\n"); 114 } 115 116 if (dmp->dm_rdonly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) { 117 debug(2, "dirfs read-only -> read-write\n"); 118 dmp->dm_rdonly = 0; 119 } 120 return 0; 121 } 122 123 dmp = kmalloc(sizeof(*dmp), M_DIRFS, M_WAITOK | M_ZERO); 124 mp->mnt_data = (qaddr_t)dmp; 125 dmp->dm_mount = mp; 126 127 error = copyinstr(data, &dmp->dm_path, MAXPATHLEN, &done); 128 if (error) { 129 /* Attempt to copy from kernel address */ 130 error = copystr(data, &dmp->dm_path, MAXPATHLEN, &done); 131 if (error) { 132 kfree(dmp, M_DIRFS); 133 goto failure; 134 } 135 } 136 137 /* Strip / character at the end to avoid problems */ 138 nlen = strnlen(dmp->dm_path, MAXPATHLEN); 139 if (dmp->dm_path[nlen-1] == '/') 140 dmp->dm_path[nlen-1] = 0; 141 142 /* Make sure host directory exists and it is indeed a directory. */ 143 if ((stat(dmp->dm_path, &st)) == 0) { 144 if (!S_ISDIR(st.st_mode)) { 145 kfree(dmp, M_DIRFS); 146 error = EINVAL; 147 goto failure; 148 } 149 } else { 150 error = errno; 151 goto failure; 152 } 153 154 lockinit(&dmp->dm_lock, "dfsmnt", 0, LK_CANRECURSE); 155 156 vfs_add_vnodeops(mp, &dirfs_vnode_vops, &mp->mnt_vn_norm_ops); 157 vfs_getnewfsid(mp); 158 159 /* Who is running the vkernel */ 160 dmp->dm_uid = getuid(); 161 dmp->dm_gid = getgid(); 162 163 TAILQ_INIT(&dmp->dm_fdlist); 164 RB_INIT(&dmp->dm_inotree); 165 166 kmalloc_raise_limit(M_DIRFS_NODE, 0); 167 168 dirfs_statfs(mp, &mp->mnt_stat, cred); 169 170 failure: 171 KTR_LOG(dirfs_mount, (dmp->dm_path) ? dmp->dm_path : "NULL", 172 dmp, mp, error); 173 174 return error; 175 } 176 177 static int 178 dirfs_unmount(struct mount *mp, int mntflags) 179 { 180 dirfs_mount_t dmp; 181 dirfs_node_t dnp; 182 int cnt; 183 int error; 184 185 debug_called(); 186 cnt = 0; 187 dmp = VFS_TO_DIRFS(mp); 188 189 error = vflush(mp, 0, 0); 190 if (error) 191 goto failure; 192 193 /* 194 * Clean up dm_fdlist. There should be no vnodes left so the 195 * only ref should be from the fdlist. 196 */ 197 while ((dnp = TAILQ_FIRST(&dmp->dm_fdlist)) != NULL) { 198 dirfs_node_setpassive(dmp, dnp, 0); 199 } 200 201 /* 202 * Cleanup root node. In the case the filesystem is mounted 203 * but no operation is done on it, there will be no call to 204 * VFS_ROOT() so better check dnp is not NULL before attempting 205 * to release it. 206 */ 207 dnp = dmp->dm_root; 208 if (dnp != NULL) { 209 dirfs_close_helper(dnp); 210 debug_node2(dnp); 211 dirfs_node_drop(dmp, dnp); /* last ref should free structure */ 212 } 213 kfree(dmp, M_DIRFS); 214 mp->mnt_data = (qaddr_t) 0; 215 216 failure: 217 KTR_LOG(dirfs_unmount, dmp, mp, error); 218 219 return error; 220 } 221 222 static int 223 dirfs_root(struct mount *mp, struct vnode **vpp) 224 { 225 dirfs_mount_t dmp; 226 dirfs_node_t dnp; 227 int fd; 228 int error; 229 230 debug_called(); 231 232 dmp = VFS_TO_DIRFS(mp); 233 KKASSERT(dmp != NULL); 234 235 if (dmp->dm_root == NULL) { 236 /* 237 * dm_root holds the root dirfs node. Allocate a new one since 238 * there is none. Also attempt to lstat(2) it, in order to set 239 * data for VOP_ACCESS() 240 */ 241 dnp = dirfs_node_alloc(mp); 242 error = dirfs_node_stat(DIRFS_NOFD, dmp->dm_path, dnp); 243 if (error != 0) { 244 dirfs_node_free(dmp, dnp); 245 return error; 246 } 247 dirfs_node_ref(dnp); /* leave inact for life of mount */ 248 249 /* Root inode's parent is NULL, used for verification */ 250 dnp->dn_parent = NULL; 251 dmp->dm_root = dnp; 252 dirfs_node_setflags(dnp, DIRFS_ROOT); 253 254 /* 255 * Maintain an open descriptor on the root dnp. The 256 * normal open/close/cache does not apply for the root 257 * so the descriptor is ALWAYS available. 258 */ 259 fd = open(dmp->dm_path, O_DIRECTORY); 260 if (fd == -1) { 261 dbg(5, "failed to open ROOT node\n"); 262 dirfs_free_vp(dmp, dnp); 263 dirfs_node_free(dmp, dnp); 264 return errno; 265 } 266 dnp->dn_fd = fd; 267 dnp->dn_type = VDIR; 268 } else { 269 dnp = dmp->dm_root; 270 } 271 272 /* 273 * Acquire the root vnode (dn_type already set above). This 274 * call will handle any races and return a locked vnode. 275 */ 276 dirfs_alloc_vp(mp, vpp, LK_CANRECURSE, dnp); 277 KTR_LOG(dirfs_root, dnp, *vpp, dmp->dm_path, dnp->dn_fd, error); 278 279 return 0; 280 } 281 282 static int 283 dirfs_fhtovp(struct mount *mp, struct vnode *rootvp, struct fid *fhp, struct vnode **vpp) 284 { 285 debug_called(); 286 287 return EOPNOTSUPP; 288 } 289 290 static int 291 dirfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred) 292 { 293 dirfs_mount_t dmp = VFS_TO_DIRFS(mp); 294 struct statfs st; 295 296 debug_called(); 297 298 if((statfs(dmp->dm_path, &st)) == -1) 299 return errno; 300 301 ksnprintf(st.f_mntfromname, MNAMELEN - 1, "dirfs@%s", dmp->dm_path); 302 bcopy(&st, sbp, sizeof(st)); 303 strlcpy(sbp->f_fstypename, mp->mnt_vfc->vfc_name, MFSNAMELEN); 304 dbg(5, "iosize = %zd\n", sbp->f_iosize); 305 306 return 0; 307 } 308 309 static int 310 dirfs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred) 311 { 312 dirfs_mount_t dmp = VFS_TO_DIRFS(mp); 313 struct statvfs st; 314 315 debug_called(); 316 317 if ((statvfs(dmp->dm_path, &st)) == -1) 318 return errno; 319 320 bcopy(&st, sbp, sizeof(st)); 321 322 return 0; 323 } 324 325 static int 326 dirfs_vptofh(struct vnode *vp, struct fid *fhp) 327 { 328 dirfs_node_t dnp; 329 330 dnp = VP_TO_NODE(vp); 331 debug_node2(dnp); 332 debug_called(); 333 334 return EOPNOTSUPP; 335 } 336 337 static int 338 dirfs_checkexp(struct mount *mp, struct sockaddr *nam, int *exflagsp, 339 struct ucred **credanonp) 340 { 341 debug_called(); 342 343 return EOPNOTSUPP; 344 } 345 346 static struct vfsops dirfs_vfsops = { 347 .vfs_mount = dirfs_mount, 348 .vfs_unmount = dirfs_unmount, 349 .vfs_root = dirfs_root, 350 .vfs_vget = vfs_stdvget, 351 .vfs_statfs = dirfs_statfs, 352 .vfs_statvfs = dirfs_statvfs, 353 .vfs_fhtovp = dirfs_fhtovp, 354 .vfs_vptofh = dirfs_vptofh, 355 .vfs_sync = vfs_stdsync, 356 .vfs_checkexp = dirfs_checkexp 357 }; 358 359 VFS_SET(dirfs_vfsops, dirfs, 0); 360 MODULE_VERSION(dirfs, 1); 361