nfs_kq.c revision 1.2.2.2
1 1.2.2.2 nathanw /* $NetBSD: nfs_kq.c,v 1.2.2.2 2002/11/11 22:16:08 nathanw Exp $ */ 2 1.2.2.2 nathanw 3 1.2.2.2 nathanw /*- 4 1.2.2.2 nathanw * Copyright (c) 2002 The NetBSD Foundation, Inc. 5 1.2.2.2 nathanw * All rights reserved. 6 1.2.2.2 nathanw * 7 1.2.2.2 nathanw * This code is derived from software contributed to The NetBSD Foundation 8 1.2.2.2 nathanw * by Jaromir Dolecek. 9 1.2.2.2 nathanw * 10 1.2.2.2 nathanw * Redistribution and use in source and binary forms, with or without 11 1.2.2.2 nathanw * modification, are permitted provided that the following conditions 12 1.2.2.2 nathanw * are met: 13 1.2.2.2 nathanw * 1. Redistributions of source code must retain the above copyright 14 1.2.2.2 nathanw * notice, this list of conditions and the following disclaimer. 15 1.2.2.2 nathanw * 2. Redistributions in binary form must reproduce the above copyright 16 1.2.2.2 nathanw * notice, this list of conditions and the following disclaimer in the 17 1.2.2.2 nathanw * documentation and/or other materials provided with the distribution. 18 1.2.2.2 nathanw * 3. All advertising materials mentioning features or use of this software 19 1.2.2.2 nathanw * must display the following acknowledgement: 20 1.2.2.2 nathanw * This product includes software developed by the NetBSD 21 1.2.2.2 nathanw * Foundation, Inc. and its contributors. 22 1.2.2.2 nathanw * 4. Neither the name of The NetBSD Foundation nor the names of its 23 1.2.2.2 nathanw * contributors may be used to endorse or promote products derived 24 1.2.2.2 nathanw * from this software without specific prior written permission. 25 1.2.2.2 nathanw * 26 1.2.2.2 nathanw * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 1.2.2.2 nathanw * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 1.2.2.2 nathanw * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 1.2.2.2 nathanw * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 1.2.2.2 nathanw * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 1.2.2.2 nathanw * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 1.2.2.2 nathanw * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 1.2.2.2 nathanw * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 1.2.2.2 nathanw * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 1.2.2.2 nathanw * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 1.2.2.2 nathanw * POSSIBILITY OF SUCH DAMAGE. 37 1.2.2.2 nathanw */ 38 1.2.2.2 nathanw 39 1.2.2.2 nathanw #include <sys/cdefs.h> 40 1.2.2.2 nathanw __KERNEL_RCSID(0, "$NetBSD: nfs_kq.c,v 1.2.2.2 2002/11/11 22:16:08 nathanw Exp $"); 41 1.2.2.2 nathanw 42 1.2.2.2 nathanw #include <sys/param.h> 43 1.2.2.2 nathanw #include <sys/systm.h> 44 1.2.2.2 nathanw #include <sys/kernel.h> 45 1.2.2.2 nathanw #include <sys/proc.h> 46 1.2.2.2 nathanw #include <sys/mount.h> 47 1.2.2.2 nathanw #include <sys/malloc.h> 48 1.2.2.2 nathanw #include <sys/vnode.h> 49 1.2.2.2 nathanw #include <sys/unistd.h> 50 1.2.2.2 nathanw #include <sys/file.h> 51 1.2.2.2 nathanw #include <sys/kthread.h> 52 1.2.2.2 nathanw 53 1.2.2.2 nathanw #include <uvm/uvm_extern.h> 54 1.2.2.2 nathanw #include <uvm/uvm.h> 55 1.2.2.2 nathanw 56 1.2.2.2 nathanw #include <nfs/rpcv2.h> 57 1.2.2.2 nathanw #include <nfs/nfsproto.h> 58 1.2.2.2 nathanw #include <nfs/nfs.h> 59 1.2.2.2 nathanw #include <nfs/nfsnode.h> 60 1.2.2.2 nathanw #include <nfs/nfs_var.h> 61 1.2.2.2 nathanw 62 1.2.2.2 nathanw struct kevq { 63 1.2.2.2 nathanw SLIST_ENTRY(kevq) kev_link; 64 1.2.2.2 nathanw struct vnode *vp; 65 1.2.2.2 nathanw u_int usecount; 66 1.2.2.2 nathanw u_int flags; 67 1.2.2.2 nathanw #define KEVQ_BUSY 0x01 /* currently being processed */ 68 1.2.2.2 nathanw #define KEVQ_WANT 0x02 /* want to change this entry */ 69 1.2.2.2 nathanw struct timespec omtime; /* old modification time */ 70 1.2.2.2 nathanw struct timespec octime; /* old change time */ 71 1.2.2.2 nathanw nlink_t onlink; /* old number of references to file */ 72 1.2.2.2 nathanw }; 73 1.2.2.2 nathanw SLIST_HEAD(kevqlist, kevq); 74 1.2.2.2 nathanw 75 1.2.2.2 nathanw static struct lock nfskevq_lock; 76 1.2.2.2 nathanw static struct proc *pnfskq; 77 1.2.2.2 nathanw static struct kevqlist kevlist = SLIST_HEAD_INITIALIZER(kevlist); 78 1.2.2.2 nathanw 79 1.2.2.2 nathanw void 80 1.2.2.2 nathanw nfs_kqinit(void) 81 1.2.2.2 nathanw { 82 1.2.2.2 nathanw lockinit(&nfskevq_lock, PSOCK, "nfskqlck", 0, 0); 83 1.2.2.2 nathanw } 84 1.2.2.2 nathanw 85 1.2.2.2 nathanw /* 86 1.2.2.2 nathanw * This quite simplistic routine periodically checks for server changes 87 1.2.2.2 nathanw * of any of the watched files every NFS_MINATTRTIME/2 seconds. 88 1.2.2.2 nathanw * Only changes in size, modification time, change time and nlinks 89 1.2.2.2 nathanw * are being checked, everything else is ignored. 90 1.2.2.2 nathanw * The routine only calls VOP_GETATTR() when it's likely it would get 91 1.2.2.2 nathanw * some new data, i.e. when the vnode expires from attrcache. This 92 1.2.2.2 nathanw * should give same result as periodically running stat(2) from userland, 93 1.2.2.2 nathanw * while keeping CPU/network usage low, and still provide proper kevent 94 1.2.2.2 nathanw * semantics. 95 1.2.2.2 nathanw * The poller thread is created when first vnode is added to watch list, 96 1.2.2.2 nathanw * and exits when the watch list is empty. The overhead of thread creation 97 1.2.2.2 nathanw * isn't really important, neither speed of attach and detach of knote. 98 1.2.2.2 nathanw */ 99 1.2.2.2 nathanw /* ARGSUSED */ 100 1.2.2.2 nathanw static void 101 1.2.2.2 nathanw nfs_kqpoll(void *arg) 102 1.2.2.2 nathanw { 103 1.2.2.2 nathanw struct kevq *ke; 104 1.2.2.2 nathanw struct vattr attr; 105 1.2.2.2 nathanw int error; 106 1.2.2.2 nathanw struct proc *p = pnfskq; 107 1.2.2.2 nathanw u_quad_t osize; 108 1.2.2.2 nathanw 109 1.2.2.2 nathanw for(;;) { 110 1.2.2.2 nathanw lockmgr(&nfskevq_lock, LK_EXCLUSIVE, NULL); 111 1.2.2.2 nathanw SLIST_FOREACH(ke, &kevlist, kev_link) { 112 1.2.2.2 nathanw /* skip if still in attrcache */ 113 1.2.2.2 nathanw if (nfs_getattrcache(ke->vp, &attr) != ENOENT) 114 1.2.2.2 nathanw continue; 115 1.2.2.2 nathanw 116 1.2.2.2 nathanw /* 117 1.2.2.2 nathanw * Mark entry busy, release lock and check 118 1.2.2.2 nathanw * for changes. 119 1.2.2.2 nathanw */ 120 1.2.2.2 nathanw ke->flags |= KEVQ_BUSY; 121 1.2.2.2 nathanw lockmgr(&nfskevq_lock, LK_RELEASE, NULL); 122 1.2.2.2 nathanw 123 1.2.2.2 nathanw /* save v_size, nfs_getattr() updates it */ 124 1.2.2.2 nathanw osize = ke->vp->v_size; 125 1.2.2.2 nathanw 126 1.2.2.2 nathanw error = VOP_GETATTR(ke->vp, &attr, p->p_ucred, p); 127 1.2.2.2 nathanw 128 1.2.2.2 nathanw /* following is a bit fragile, but about best 129 1.2.2.2 nathanw * we can get */ 130 1.2.2.2 nathanw if (attr.va_size != osize) { 131 1.2.2.2 nathanw int extended = (attr.va_size > osize); 132 1.2.2.2 nathanw VN_KNOTE(ke->vp, NOTE_WRITE 133 1.2.2.2 nathanw | (extended ? NOTE_EXTEND : 0)); 134 1.2.2.2 nathanw ke->omtime = attr.va_mtime; 135 1.2.2.2 nathanw } else if (attr.va_mtime.tv_sec != ke->omtime.tv_sec 136 1.2.2.2 nathanw || attr.va_mtime.tv_nsec != ke->omtime.tv_nsec) { 137 1.2.2.2 nathanw VN_KNOTE(ke->vp, NOTE_WRITE); 138 1.2.2.2 nathanw ke->omtime = attr.va_mtime; 139 1.2.2.2 nathanw } 140 1.2.2.2 nathanw 141 1.2.2.2 nathanw if (attr.va_ctime.tv_sec != ke->octime.tv_sec 142 1.2.2.2 nathanw || attr.va_ctime.tv_nsec != ke->octime.tv_nsec) { 143 1.2.2.2 nathanw VN_KNOTE(ke->vp, NOTE_ATTRIB); 144 1.2.2.2 nathanw ke->octime = attr.va_ctime; 145 1.2.2.2 nathanw } 146 1.2.2.2 nathanw 147 1.2.2.2 nathanw if (attr.va_nlink != ke->onlink) { 148 1.2.2.2 nathanw VN_KNOTE(ke->vp, NOTE_LINK); 149 1.2.2.2 nathanw ke->onlink = attr.va_nlink; 150 1.2.2.2 nathanw } 151 1.2.2.2 nathanw 152 1.2.2.2 nathanw lockmgr(&nfskevq_lock, LK_EXCLUSIVE, NULL); 153 1.2.2.2 nathanw ke->flags &= ~KEVQ_BUSY; 154 1.2.2.2 nathanw if (ke->flags & KEVQ_WANT) { 155 1.2.2.2 nathanw ke->flags &= ~KEVQ_WANT; 156 1.2.2.2 nathanw wakeup(ke); 157 1.2.2.2 nathanw } 158 1.2.2.2 nathanw } 159 1.2.2.2 nathanw 160 1.2.2.2 nathanw if (SLIST_EMPTY(&kevlist)) { 161 1.2.2.2 nathanw /* Nothing more to watch, exit */ 162 1.2.2.2 nathanw pnfskq = NULL; 163 1.2.2.2 nathanw lockmgr(&nfskevq_lock, LK_RELEASE, NULL); 164 1.2.2.2 nathanw kthread_exit(0); 165 1.2.2.2 nathanw } 166 1.2.2.2 nathanw lockmgr(&nfskevq_lock, LK_RELEASE, NULL); 167 1.2.2.2 nathanw 168 1.2.2.2 nathanw /* wait a while before checking for changes again */ 169 1.2.2.2 nathanw tsleep(pnfskq, PSOCK, "nfskqpw", 170 1.2.2.2 nathanw NFS_MINATTRTIMO * hz / 2); 171 1.2.2.2 nathanw 172 1.2.2.2 nathanw } 173 1.2.2.2 nathanw } 174 1.2.2.2 nathanw 175 1.2.2.2 nathanw static void 176 1.2.2.2 nathanw filt_nfsdetach(struct knote *kn) 177 1.2.2.2 nathanw { 178 1.2.2.2 nathanw struct vnode *vp = (struct vnode *)kn->kn_hook; 179 1.2.2.2 nathanw struct kevq *ke; 180 1.2.2.2 nathanw 181 1.2.2.2 nathanw /* XXXLUKEM lock the struct? */ 182 1.2.2.2 nathanw SLIST_REMOVE(&vp->v_klist, kn, knote, kn_selnext); 183 1.2.2.2 nathanw 184 1.2.2.2 nathanw /* Remove the vnode from watch list */ 185 1.2.2.2 nathanw lockmgr(&nfskevq_lock, LK_EXCLUSIVE, NULL); 186 1.2.2.2 nathanw SLIST_FOREACH(ke, &kevlist, kev_link) { 187 1.2.2.2 nathanw if (ke->vp == vp) { 188 1.2.2.2 nathanw while (ke->flags & KEVQ_BUSY) { 189 1.2.2.2 nathanw ke->flags |= KEVQ_WANT; 190 1.2.2.2 nathanw lockmgr(&nfskevq_lock, LK_RELEASE, NULL); 191 1.2.2.2 nathanw (void) tsleep(ke, PSOCK, "nfskqdet", 0); 192 1.2.2.2 nathanw lockmgr(&nfskevq_lock, LK_EXCLUSIVE, NULL); 193 1.2.2.2 nathanw } 194 1.2.2.2 nathanw 195 1.2.2.2 nathanw if (ke->usecount > 1) { 196 1.2.2.2 nathanw /* keep, other kevents need this */ 197 1.2.2.2 nathanw ke->usecount--; 198 1.2.2.2 nathanw } else { 199 1.2.2.2 nathanw /* last user, g/c */ 200 1.2.2.2 nathanw SLIST_REMOVE(&kevlist, ke, kevq, kev_link); 201 1.2.2.2 nathanw FREE(ke, M_KEVENT); 202 1.2.2.2 nathanw } 203 1.2.2.2 nathanw break; 204 1.2.2.2 nathanw } 205 1.2.2.2 nathanw } 206 1.2.2.2 nathanw lockmgr(&nfskevq_lock, LK_RELEASE, NULL); 207 1.2.2.2 nathanw } 208 1.2.2.2 nathanw 209 1.2.2.2 nathanw static int 210 1.2.2.2 nathanw filt_nfsread(struct knote *kn, long hint) 211 1.2.2.2 nathanw { 212 1.2.2.2 nathanw struct vnode *vp = (struct vnode *)kn->kn_hook; 213 1.2.2.2 nathanw 214 1.2.2.2 nathanw /* 215 1.2.2.2 nathanw * filesystem is gone, so set the EOF flag and schedule 216 1.2.2.2 nathanw * the knote for deletion. 217 1.2.2.2 nathanw */ 218 1.2.2.2 nathanw if (hint == NOTE_REVOKE) { 219 1.2.2.2 nathanw kn->kn_flags |= (EV_EOF | EV_ONESHOT); 220 1.2.2.2 nathanw return (1); 221 1.2.2.2 nathanw } 222 1.2.2.2 nathanw 223 1.2.2.2 nathanw /* XXXLUKEM lock the struct? */ 224 1.2.2.2 nathanw kn->kn_data = vp->v_size - kn->kn_fp->f_offset; 225 1.2.2.2 nathanw return (kn->kn_data != 0); 226 1.2.2.2 nathanw } 227 1.2.2.2 nathanw 228 1.2.2.2 nathanw static int 229 1.2.2.2 nathanw filt_nfsvnode(struct knote *kn, long hint) 230 1.2.2.2 nathanw { 231 1.2.2.2 nathanw 232 1.2.2.2 nathanw if (kn->kn_sfflags & hint) 233 1.2.2.2 nathanw kn->kn_fflags |= hint; 234 1.2.2.2 nathanw if (hint == NOTE_REVOKE) { 235 1.2.2.2 nathanw kn->kn_flags |= EV_EOF; 236 1.2.2.2 nathanw return (1); 237 1.2.2.2 nathanw } 238 1.2.2.2 nathanw return (kn->kn_fflags != 0); 239 1.2.2.2 nathanw } 240 1.2.2.2 nathanw 241 1.2.2.2 nathanw static const struct filterops nfsread_filtops = 242 1.2.2.2 nathanw { 1, NULL, filt_nfsdetach, filt_nfsread }; 243 1.2.2.2 nathanw static const struct filterops nfsvnode_filtops = 244 1.2.2.2 nathanw { 1, NULL, filt_nfsdetach, filt_nfsvnode }; 245 1.2.2.2 nathanw 246 1.2.2.2 nathanw int 247 1.2.2.2 nathanw nfs_kqfilter(void *v) 248 1.2.2.2 nathanw { 249 1.2.2.2 nathanw struct vop_kqfilter_args /* { 250 1.2.2.2 nathanw struct vnode *a_vp; 251 1.2.2.2 nathanw struct knote *a_kn; 252 1.2.2.2 nathanw } */ *ap = v; 253 1.2.2.2 nathanw struct vnode *vp; 254 1.2.2.2 nathanw struct knote *kn; 255 1.2.2.2 nathanw struct kevq *ke; 256 1.2.2.2 nathanw int error = 0; 257 1.2.2.2 nathanw struct vattr attr; 258 1.2.2.2 nathanw struct proc *p = curproc; /* XXX */ 259 1.2.2.2 nathanw 260 1.2.2.2 nathanw vp = ap->a_vp; 261 1.2.2.2 nathanw kn = ap->a_kn; 262 1.2.2.2 nathanw switch (kn->kn_filter) { 263 1.2.2.2 nathanw case EVFILT_READ: 264 1.2.2.2 nathanw kn->kn_fop = &nfsread_filtops; 265 1.2.2.2 nathanw break; 266 1.2.2.2 nathanw case EVFILT_VNODE: 267 1.2.2.2 nathanw kn->kn_fop = &nfsvnode_filtops; 268 1.2.2.2 nathanw break; 269 1.2.2.2 nathanw default: 270 1.2.2.2 nathanw return (1); 271 1.2.2.2 nathanw } 272 1.2.2.2 nathanw 273 1.2.2.2 nathanw kn->kn_hook = vp; 274 1.2.2.2 nathanw 275 1.2.2.2 nathanw /* XXXLUKEM lock the struct? */ 276 1.2.2.2 nathanw SLIST_INSERT_HEAD(&vp->v_klist, kn, kn_selnext); 277 1.2.2.2 nathanw 278 1.2.2.2 nathanw /* 279 1.2.2.2 nathanw * Put the vnode to watched list. 280 1.2.2.2 nathanw */ 281 1.2.2.2 nathanw 282 1.2.2.2 nathanw /* 283 1.2.2.2 nathanw * Fetch current attributes. It's only needed when the vnode 284 1.2.2.2 nathanw * is not watched yet, but we need to do this without lock 285 1.2.2.2 nathanw * held. This is likely cheap due to attrcache, so do it now. 286 1.2.2.2 nathanw */ 287 1.2.2.2 nathanw memset(&attr, 0, sizeof(attr)); 288 1.2.2.2 nathanw (void) VOP_GETATTR(vp, &attr, p->p_ucred, p); 289 1.2.2.2 nathanw 290 1.2.2.2 nathanw lockmgr(&nfskevq_lock, LK_EXCLUSIVE, NULL); 291 1.2.2.2 nathanw 292 1.2.2.2 nathanw /* ensure the poller is running */ 293 1.2.2.2 nathanw if (!pnfskq) { 294 1.2.2.2 nathanw error = kthread_create1(nfs_kqpoll, NULL, &pnfskq, 295 1.2.2.2 nathanw "nfskqpoll"); 296 1.2.2.2 nathanw if (error) 297 1.2.2.2 nathanw goto out; 298 1.2.2.2 nathanw } 299 1.2.2.2 nathanw 300 1.2.2.2 nathanw SLIST_FOREACH(ke, &kevlist, kev_link) { 301 1.2.2.2 nathanw if (ke->vp == vp) 302 1.2.2.2 nathanw break; 303 1.2.2.2 nathanw } 304 1.2.2.2 nathanw 305 1.2.2.2 nathanw if (ke) { 306 1.2.2.2 nathanw /* already watched, so just bump usecount */ 307 1.2.2.2 nathanw ke->usecount++; 308 1.2.2.2 nathanw } else { 309 1.2.2.2 nathanw /* need a new one */ 310 1.2.2.2 nathanw MALLOC(ke, struct kevq *, sizeof(struct kevq), M_KEVENT, 311 1.2.2.2 nathanw M_WAITOK); 312 1.2.2.2 nathanw ke->vp = vp; 313 1.2.2.2 nathanw ke->usecount = 1; 314 1.2.2.2 nathanw ke->flags = 0; 315 1.2.2.2 nathanw ke->omtime = attr.va_mtime; 316 1.2.2.2 nathanw ke->octime = attr.va_ctime; 317 1.2.2.2 nathanw ke->onlink = attr.va_nlink; 318 1.2.2.2 nathanw SLIST_INSERT_HEAD(&kevlist, ke, kev_link); 319 1.2.2.2 nathanw } 320 1.2.2.2 nathanw 321 1.2.2.2 nathanw /* kick the poller */ 322 1.2.2.2 nathanw wakeup(pnfskq); 323 1.2.2.2 nathanw 324 1.2.2.2 nathanw out: 325 1.2.2.2 nathanw lockmgr(&nfskevq_lock, LK_RELEASE, NULL); 326 1.2.2.2 nathanw 327 1.2.2.2 nathanw return (error); 328 1.2.2.2 nathanw } 329
Indexes created Tue Oct 21 12:09:54 GMT 2025