vfs_vnode.c revision 1.5.2.3
1 1.5.2.3 rmind /* $NetBSD: vfs_vnode.c,v 1.5.2.3 2011/05/19 03:43:03 rmind Exp $ */ 2 1.5.2.2 rmind 3 1.5.2.2 rmind /*- 4 1.5.2.2 rmind * Copyright (c) 1997-2011 The NetBSD Foundation, Inc. 5 1.5.2.2 rmind * All rights reserved. 6 1.5.2.2 rmind * 7 1.5.2.2 rmind * This code is derived from software contributed to The NetBSD Foundation 8 1.5.2.2 rmind * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 1.5.2.2 rmind * NASA Ames Research Center, by Charles M. Hannum, and by Andrew Doran. 10 1.5.2.2 rmind * 11 1.5.2.2 rmind * Redistribution and use in source and binary forms, with or without 12 1.5.2.2 rmind * modification, are permitted provided that the following conditions 13 1.5.2.2 rmind * are met: 14 1.5.2.2 rmind * 1. Redistributions of source code must retain the above copyright 15 1.5.2.2 rmind * notice, this list of conditions and the following disclaimer. 16 1.5.2.2 rmind * 2. Redistributions in binary form must reproduce the above copyright 17 1.5.2.2 rmind * notice, this list of conditions and the following disclaimer in the 18 1.5.2.2 rmind * documentation and/or other materials provided with the distribution. 19 1.5.2.2 rmind * 20 1.5.2.2 rmind * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 1.5.2.2 rmind * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 1.5.2.2 rmind * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 1.5.2.2 rmind * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 1.5.2.2 rmind * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 1.5.2.2 rmind * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 1.5.2.2 rmind * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 1.5.2.2 rmind * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 1.5.2.2 rmind * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 1.5.2.2 rmind * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 1.5.2.2 rmind * POSSIBILITY OF SUCH DAMAGE. 31 1.5.2.2 rmind */ 32 1.5.2.2 rmind 33 1.5.2.2 rmind /* 34 1.5.2.2 rmind * Copyright (c) 1989, 1993 35 1.5.2.2 rmind * The Regents of the University of California. All rights reserved. 36 1.5.2.2 rmind * (c) UNIX System Laboratories, Inc. 37 1.5.2.2 rmind * All or some portions of this file are derived from material licensed 38 1.5.2.2 rmind * to the University of California by American Telephone and Telegraph 39 1.5.2.2 rmind * Co. or Unix System Laboratories, Inc. and are reproduced herein with 40 1.5.2.2 rmind * the permission of UNIX System Laboratories, Inc. 41 1.5.2.2 rmind * 42 1.5.2.2 rmind * Redistribution and use in source and binary forms, with or without 43 1.5.2.2 rmind * modification, are permitted provided that the following conditions 44 1.5.2.2 rmind * are met: 45 1.5.2.2 rmind * 1. Redistributions of source code must retain the above copyright 46 1.5.2.2 rmind * notice, this list of conditions and the following disclaimer. 47 1.5.2.2 rmind * 2. Redistributions in binary form must reproduce the above copyright 48 1.5.2.2 rmind * notice, this list of conditions and the following disclaimer in the 49 1.5.2.2 rmind * documentation and/or other materials provided with the distribution. 50 1.5.2.2 rmind * 3. Neither the name of the University nor the names of its contributors 51 1.5.2.2 rmind * may be used to endorse or promote products derived from this software 52 1.5.2.2 rmind * without specific prior written permission. 53 1.5.2.2 rmind * 54 1.5.2.2 rmind * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 55 1.5.2.2 rmind * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 56 1.5.2.2 rmind * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 57 1.5.2.2 rmind * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 58 1.5.2.2 rmind * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 59 1.5.2.2 rmind * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 60 1.5.2.2 rmind * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 61 1.5.2.2 rmind * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 62 1.5.2.2 rmind * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 63 1.5.2.2 rmind * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 64 1.5.2.2 rmind * SUCH DAMAGE. 65 1.5.2.2 rmind * 66 1.5.2.2 rmind * @(#)vfs_subr.c 8.13 (Berkeley) 4/18/94 67 1.5.2.2 rmind */ 68 1.5.2.2 rmind 69 1.5.2.2 rmind /* 70 1.5.2.2 rmind * Note on v_usecount and locking: 71 1.5.2.2 rmind * 72 1.5.2.2 rmind * At nearly all points it is known that v_usecount could be zero, the 73 1.5.2.2 rmind * vnode interlock will be held. 74 1.5.2.2 rmind * 75 1.5.2.2 rmind * To change v_usecount away from zero, the interlock must be held. To 76 1.5.2.2 rmind * change from a non-zero value to zero, again the interlock must be 77 1.5.2.2 rmind * held. 78 1.5.2.2 rmind * 79 1.5.2.2 rmind * There's a flag bit, VC_XLOCK, embedded in v_usecount. 80 1.5.2.2 rmind * To raise v_usecount, if the VC_XLOCK bit is set in it, the interlock 81 1.5.2.2 rmind * must be held. 82 1.5.2.2 rmind * To modify the VC_XLOCK bit, the interlock must be held. 83 1.5.2.2 rmind * We always keep the usecount (v_usecount & VC_MASK) non-zero while the 84 1.5.2.2 rmind * VC_XLOCK bit is set. 85 1.5.2.2 rmind * 86 1.5.2.2 rmind * Unless the VC_XLOCK bit is set, changing the usecount from a non-zero 87 1.5.2.2 rmind * value to a non-zero value can safely be done using atomic operations, 88 1.5.2.2 rmind * without the interlock held. 89 1.5.2.2 rmind * Even if the VC_XLOCK bit is set, decreasing the usecount to a non-zero 90 1.5.2.2 rmind * value can be done using atomic operations, without the interlock held. 91 1.5.2.2 rmind */ 92 1.5.2.2 rmind 93 1.5.2.2 rmind #include <sys/cdefs.h> 94 1.5.2.3 rmind __KERNEL_RCSID(0, "$NetBSD: vfs_vnode.c,v 1.5.2.3 2011/05/19 03:43:03 rmind Exp $"); 95 1.5.2.2 rmind 96 1.5.2.2 rmind #include <sys/param.h> 97 1.5.2.2 rmind #include <sys/kernel.h> 98 1.5.2.2 rmind 99 1.5.2.2 rmind #include <sys/atomic.h> 100 1.5.2.2 rmind #include <sys/buf.h> 101 1.5.2.2 rmind #include <sys/conf.h> 102 1.5.2.2 rmind #include <sys/device.h> 103 1.5.2.2 rmind #include <sys/kauth.h> 104 1.5.2.2 rmind #include <sys/kmem.h> 105 1.5.2.2 rmind #include <sys/kthread.h> 106 1.5.2.2 rmind #include <sys/module.h> 107 1.5.2.2 rmind #include <sys/mount.h> 108 1.5.2.2 rmind #include <sys/namei.h> 109 1.5.2.2 rmind #include <sys/syscallargs.h> 110 1.5.2.2 rmind #include <sys/sysctl.h> 111 1.5.2.2 rmind #include <sys/systm.h> 112 1.5.2.2 rmind #include <sys/vnode.h> 113 1.5.2.2 rmind #include <sys/wapbl.h> 114 1.5.2.2 rmind 115 1.5.2.2 rmind #include <uvm/uvm.h> 116 1.5.2.2 rmind #include <uvm/uvm_readahead.h> 117 1.5.2.2 rmind 118 1.5.2.2 rmind u_int numvnodes; 119 1.5.2.2 rmind 120 1.5.2.2 rmind static pool_cache_t vnode_cache; 121 1.5.2.2 rmind static kmutex_t vnode_free_list_lock; 122 1.5.2.2 rmind 123 1.5.2.2 rmind static vnodelst_t vnode_free_list; 124 1.5.2.2 rmind static vnodelst_t vnode_hold_list; 125 1.5.2.2 rmind static vnodelst_t vrele_list; 126 1.5.2.2 rmind 127 1.5.2.2 rmind static kmutex_t vrele_lock; 128 1.5.2.2 rmind static kcondvar_t vrele_cv; 129 1.5.2.2 rmind static lwp_t * vrele_lwp; 130 1.5.2.2 rmind static int vrele_pending; 131 1.5.2.2 rmind static int vrele_gen; 132 1.5.2.2 rmind 133 1.5.2.2 rmind static vnode_t * getcleanvnode(void); 134 1.5.2.2 rmind static void vrele_thread(void *); 135 1.5.2.2 rmind static void vpanic(vnode_t *, const char *); 136 1.5.2.2 rmind 137 1.5.2.2 rmind /* Routines having to do with the management of the vnode table. */ 138 1.5.2.2 rmind extern int (**dead_vnodeop_p)(void *); 139 1.5.2.2 rmind 140 1.5.2.2 rmind void 141 1.5.2.2 rmind vfs_vnode_sysinit(void) 142 1.5.2.2 rmind { 143 1.5.2.2 rmind int error; 144 1.5.2.2 rmind 145 1.5.2.2 rmind vnode_cache = pool_cache_init(sizeof(vnode_t), 0, 0, 0, "vnodepl", 146 1.5.2.2 rmind NULL, IPL_NONE, NULL, NULL, NULL); 147 1.5.2.2 rmind KASSERT(vnode_cache != NULL); 148 1.5.2.2 rmind 149 1.5.2.2 rmind mutex_init(&vnode_free_list_lock, MUTEX_DEFAULT, IPL_NONE); 150 1.5.2.2 rmind TAILQ_INIT(&vnode_free_list); 151 1.5.2.2 rmind TAILQ_INIT(&vnode_hold_list); 152 1.5.2.2 rmind TAILQ_INIT(&vrele_list); 153 1.5.2.2 rmind 154 1.5.2.2 rmind mutex_init(&vrele_lock, MUTEX_DEFAULT, IPL_NONE); 155 1.5.2.2 rmind cv_init(&vrele_cv, "vrele"); 156 1.5.2.2 rmind error = kthread_create(PRI_VM, KTHREAD_MPSAFE, NULL, vrele_thread, 157 1.5.2.2 rmind NULL, &vrele_lwp, "vrele"); 158 1.5.2.2 rmind KASSERT(error == 0); 159 1.5.2.2 rmind } 160 1.5.2.2 rmind 161 1.5.2.2 rmind /* 162 1.5.2.2 rmind * Allocate a new, uninitialized vnode. If 'mp' is non-NULL, this is a 163 1.5.2.2 rmind * marker vnode and we are prepared to wait for the allocation. 164 1.5.2.2 rmind */ 165 1.5.2.2 rmind vnode_t * 166 1.5.2.2 rmind vnalloc(struct mount *mp) 167 1.5.2.2 rmind { 168 1.5.2.2 rmind vnode_t *vp; 169 1.5.2.2 rmind 170 1.5.2.2 rmind vp = pool_cache_get(vnode_cache, (mp != NULL ? PR_WAITOK : PR_NOWAIT)); 171 1.5.2.2 rmind if (vp == NULL) { 172 1.5.2.2 rmind return NULL; 173 1.5.2.2 rmind } 174 1.5.2.2 rmind 175 1.5.2.2 rmind memset(vp, 0, sizeof(*vp)); 176 1.5.2.3 rmind uvm_obj_init(&vp->v_uobj, &uvm_vnodeops, true, 0); 177 1.5.2.2 rmind cv_init(&vp->v_cv, "vnode"); 178 1.5.2.2 rmind /* 179 1.5.2.2 rmind * Done by memset() above. 180 1.5.2.2 rmind * LIST_INIT(&vp->v_nclist); 181 1.5.2.2 rmind * LIST_INIT(&vp->v_dnclist); 182 1.5.2.2 rmind */ 183 1.5.2.2 rmind 184 1.5.2.2 rmind if (mp != NULL) { 185 1.5.2.2 rmind vp->v_mount = mp; 186 1.5.2.2 rmind vp->v_type = VBAD; 187 1.5.2.2 rmind vp->v_iflag = VI_MARKER; 188 1.5.2.2 rmind } else { 189 1.5.2.2 rmind rw_init(&vp->v_lock); 190 1.5.2.2 rmind } 191 1.5.2.2 rmind 192 1.5.2.2 rmind return vp; 193 1.5.2.2 rmind } 194 1.5.2.2 rmind 195 1.5.2.2 rmind /* 196 1.5.2.2 rmind * Free an unused, unreferenced vnode. 197 1.5.2.2 rmind */ 198 1.5.2.2 rmind void 199 1.5.2.2 rmind vnfree(vnode_t *vp) 200 1.5.2.2 rmind { 201 1.5.2.2 rmind 202 1.5.2.2 rmind KASSERT(vp->v_usecount == 0); 203 1.5.2.2 rmind 204 1.5.2.2 rmind if ((vp->v_iflag & VI_MARKER) == 0) { 205 1.5.2.2 rmind rw_destroy(&vp->v_lock); 206 1.5.2.2 rmind mutex_enter(&vnode_free_list_lock); 207 1.5.2.2 rmind numvnodes--; 208 1.5.2.2 rmind mutex_exit(&vnode_free_list_lock); 209 1.5.2.2 rmind } 210 1.5.2.2 rmind 211 1.5.2.3 rmind /* 212 1.5.2.3 rmind * Note: the vnode interlock will either be freed, of reference 213 1.5.2.3 rmind * dropped (if VI_LOCKSHARE was in use). 214 1.5.2.3 rmind */ 215 1.5.2.3 rmind uvm_obj_destroy(&vp->v_uobj, true); 216 1.5.2.2 rmind cv_destroy(&vp->v_cv); 217 1.5.2.2 rmind pool_cache_put(vnode_cache, vp); 218 1.5.2.2 rmind } 219 1.5.2.2 rmind 220 1.5.2.2 rmind /* 221 1.5.2.2 rmind * getcleanvnode: grab a vnode from freelist and clean it. 222 1.5.2.2 rmind * 223 1.5.2.2 rmind * => Releases vnode_free_list_lock. 224 1.5.2.2 rmind * => Returns referenced vnode on success. 225 1.5.2.2 rmind */ 226 1.5.2.2 rmind static vnode_t * 227 1.5.2.2 rmind getcleanvnode(void) 228 1.5.2.2 rmind { 229 1.5.2.2 rmind vnode_t *vp; 230 1.5.2.2 rmind vnodelst_t *listhd; 231 1.5.2.2 rmind 232 1.5.2.2 rmind KASSERT(mutex_owned(&vnode_free_list_lock)); 233 1.5.2.2 rmind retry: 234 1.5.2.2 rmind listhd = &vnode_free_list; 235 1.5.2.2 rmind try_nextlist: 236 1.5.2.2 rmind TAILQ_FOREACH(vp, listhd, v_freelist) { 237 1.5.2.2 rmind /* 238 1.5.2.2 rmind * It's safe to test v_usecount and v_iflag 239 1.5.2.2 rmind * without holding the interlock here, since 240 1.5.2.2 rmind * these vnodes should never appear on the 241 1.5.2.2 rmind * lists. 242 1.5.2.2 rmind */ 243 1.5.2.2 rmind KASSERT(vp->v_usecount == 0); 244 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_CLEAN) == 0); 245 1.5.2.2 rmind KASSERT(vp->v_freelisthd == listhd); 246 1.5.2.2 rmind 247 1.5.2.2 rmind if (!mutex_tryenter(vp->v_interlock)) 248 1.5.2.2 rmind continue; 249 1.5.2.2 rmind if ((vp->v_iflag & VI_XLOCK) == 0) 250 1.5.2.2 rmind break; 251 1.5.2.2 rmind mutex_exit(vp->v_interlock); 252 1.5.2.2 rmind } 253 1.5.2.2 rmind 254 1.5.2.2 rmind if (vp == NULL) { 255 1.5.2.2 rmind if (listhd == &vnode_free_list) { 256 1.5.2.2 rmind listhd = &vnode_hold_list; 257 1.5.2.2 rmind goto try_nextlist; 258 1.5.2.2 rmind } 259 1.5.2.2 rmind mutex_exit(&vnode_free_list_lock); 260 1.5.2.2 rmind return NULL; 261 1.5.2.2 rmind } 262 1.5.2.2 rmind 263 1.5.2.2 rmind /* Remove it from the freelist. */ 264 1.5.2.2 rmind TAILQ_REMOVE(listhd, vp, v_freelist); 265 1.5.2.2 rmind vp->v_freelisthd = NULL; 266 1.5.2.2 rmind mutex_exit(&vnode_free_list_lock); 267 1.5.2.2 rmind 268 1.5.2.2 rmind KASSERT(vp->v_usecount == 0); 269 1.5.2.2 rmind 270 1.5.2.2 rmind /* 271 1.5.2.2 rmind * The vnode is still associated with a file system, so we must 272 1.5.2.2 rmind * clean it out before reusing it. We need to add a reference 273 1.5.2.2 rmind * before doing this. If the vnode gains another reference while 274 1.5.2.2 rmind * being cleaned out then we lose - retry. 275 1.5.2.2 rmind */ 276 1.5.2.2 rmind atomic_add_int(&vp->v_usecount, 1 + VC_XLOCK); 277 1.5.2.2 rmind vclean(vp, DOCLOSE); 278 1.5.2.2 rmind KASSERT(vp->v_usecount >= 1 + VC_XLOCK); 279 1.5.2.2 rmind atomic_add_int(&vp->v_usecount, -VC_XLOCK); 280 1.5.2.2 rmind if (vp->v_usecount == 1) { 281 1.5.2.2 rmind /* We're about to dirty it. */ 282 1.5.2.2 rmind vp->v_iflag &= ~VI_CLEAN; 283 1.5.2.2 rmind mutex_exit(vp->v_interlock); 284 1.5.2.2 rmind if (vp->v_type == VBLK || vp->v_type == VCHR) { 285 1.5.2.2 rmind spec_node_destroy(vp); 286 1.5.2.2 rmind } 287 1.5.2.2 rmind vp->v_type = VNON; 288 1.5.2.2 rmind } else { 289 1.5.2.2 rmind /* 290 1.5.2.2 rmind * Don't return to freelist - the holder of the last 291 1.5.2.2 rmind * reference will destroy it. 292 1.5.2.2 rmind */ 293 1.5.2.2 rmind vrelel(vp, 0); /* releases vp->v_interlock */ 294 1.5.2.2 rmind mutex_enter(&vnode_free_list_lock); 295 1.5.2.2 rmind goto retry; 296 1.5.2.2 rmind } 297 1.5.2.2 rmind 298 1.5.2.2 rmind KASSERT(vp->v_data == NULL); 299 1.5.2.2 rmind KASSERT(vp->v_uobj.uo_npages == 0); 300 1.5.2.2 rmind KASSERT(TAILQ_EMPTY(&vp->v_uobj.memq)); 301 1.5.2.2 rmind KASSERT(vp->v_numoutput == 0); 302 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_ONWORKLST) == 0); 303 1.5.2.2 rmind 304 1.5.2.2 rmind return vp; 305 1.5.2.2 rmind } 306 1.5.2.2 rmind 307 1.5.2.2 rmind /* 308 1.5.2.2 rmind * getnewvnode: return the next vnode from the free list. 309 1.5.2.2 rmind * 310 1.5.2.2 rmind * => Returns referenced vnode, moved into the mount queue. 311 1.5.2.3 rmind * => Shares the lock with vnode specified by 'svp', if it is not NULL. 312 1.5.2.2 rmind */ 313 1.5.2.2 rmind int 314 1.5.2.2 rmind getnewvnode(enum vtagtype tag, struct mount *mp, int (**vops)(void *), 315 1.5.2.3 rmind const vnode_t *svp, vnode_t **vpp) 316 1.5.2.2 rmind { 317 1.5.2.2 rmind struct uvm_object *uobj; 318 1.5.2.2 rmind static int toggle; 319 1.5.2.2 rmind vnode_t *vp; 320 1.5.2.2 rmind int error = 0, tryalloc; 321 1.5.2.2 rmind 322 1.5.2.2 rmind try_again: 323 1.5.2.2 rmind if (mp != NULL) { 324 1.5.2.2 rmind /* 325 1.5.2.2 rmind * Mark filesystem busy while we are creating a vnode. 326 1.5.2.2 rmind * If unmount is in progress, this will fail. 327 1.5.2.2 rmind */ 328 1.5.2.2 rmind error = vfs_busy(mp, NULL); 329 1.5.2.2 rmind if (error) 330 1.5.2.2 rmind return error; 331 1.5.2.2 rmind } 332 1.5.2.2 rmind 333 1.5.2.2 rmind /* 334 1.5.2.2 rmind * We must choose whether to allocate a new vnode or recycle an 335 1.5.2.2 rmind * existing one. The criterion for allocating a new one is that 336 1.5.2.2 rmind * the total number of vnodes is less than the number desired or 337 1.5.2.2 rmind * there are no vnodes on either free list. Generally we only 338 1.5.2.2 rmind * want to recycle vnodes that have no buffers associated with 339 1.5.2.2 rmind * them, so we look first on the vnode_free_list. If it is empty, 340 1.5.2.2 rmind * we next consider vnodes with referencing buffers on the 341 1.5.2.2 rmind * vnode_hold_list. The toggle ensures that half the time we 342 1.5.2.2 rmind * will use a buffer from the vnode_hold_list, and half the time 343 1.5.2.2 rmind * we will allocate a new one unless the list has grown to twice 344 1.5.2.2 rmind * the desired size. We are reticent to recycle vnodes from the 345 1.5.2.2 rmind * vnode_hold_list because we will lose the identity of all its 346 1.5.2.2 rmind * referencing buffers. 347 1.5.2.2 rmind */ 348 1.5.2.2 rmind 349 1.5.2.2 rmind vp = NULL; 350 1.5.2.2 rmind 351 1.5.2.2 rmind mutex_enter(&vnode_free_list_lock); 352 1.5.2.2 rmind 353 1.5.2.2 rmind toggle ^= 1; 354 1.5.2.2 rmind if (numvnodes > 2 * desiredvnodes) 355 1.5.2.2 rmind toggle = 0; 356 1.5.2.2 rmind 357 1.5.2.2 rmind tryalloc = numvnodes < desiredvnodes || 358 1.5.2.2 rmind (TAILQ_FIRST(&vnode_free_list) == NULL && 359 1.5.2.2 rmind (TAILQ_FIRST(&vnode_hold_list) == NULL || toggle)); 360 1.5.2.2 rmind 361 1.5.2.2 rmind if (tryalloc) { 362 1.5.2.2 rmind /* Allocate a new vnode. */ 363 1.5.2.2 rmind numvnodes++; 364 1.5.2.2 rmind mutex_exit(&vnode_free_list_lock); 365 1.5.2.2 rmind if ((vp = vnalloc(NULL)) == NULL) { 366 1.5.2.2 rmind mutex_enter(&vnode_free_list_lock); 367 1.5.2.2 rmind numvnodes--; 368 1.5.2.2 rmind } else 369 1.5.2.2 rmind vp->v_usecount = 1; 370 1.5.2.2 rmind } 371 1.5.2.2 rmind 372 1.5.2.2 rmind if (vp == NULL) { 373 1.5.2.2 rmind /* Recycle and get vnode clean. */ 374 1.5.2.2 rmind vp = getcleanvnode(); 375 1.5.2.2 rmind if (vp == NULL) { 376 1.5.2.2 rmind if (mp != NULL) { 377 1.5.2.2 rmind vfs_unbusy(mp, false, NULL); 378 1.5.2.2 rmind } 379 1.5.2.2 rmind if (tryalloc) { 380 1.5.2.2 rmind printf("WARNING: unable to allocate new " 381 1.5.2.2 rmind "vnode, retrying...\n"); 382 1.5.2.2 rmind kpause("newvn", false, hz, NULL); 383 1.5.2.2 rmind goto try_again; 384 1.5.2.2 rmind } 385 1.5.2.2 rmind tablefull("vnode", "increase kern.maxvnodes or NVNODE"); 386 1.5.2.2 rmind *vpp = 0; 387 1.5.2.2 rmind return ENFILE; 388 1.5.2.2 rmind } 389 1.5.2.3 rmind if ((vp->v_iflag & VI_LOCKSHARE) != 0 || svp) { 390 1.5.2.3 rmind /* We must remove vnode from the old mount point. */ 391 1.5.2.3 rmind if (vp->v_mount) { 392 1.5.2.3 rmind vfs_insmntque(vp, NULL); 393 1.5.2.3 rmind } 394 1.5.2.3 rmind /* Allocate a new interlock, if it was shared. */ 395 1.5.2.3 rmind if (vp->v_iflag & VI_LOCKSHARE) { 396 1.5.2.3 rmind uvm_obj_setlock(&vp->v_uobj, NULL); 397 1.5.2.3 rmind vp->v_iflag &= ~VI_LOCKSHARE; 398 1.5.2.3 rmind } 399 1.5.2.3 rmind } 400 1.5.2.2 rmind vp->v_iflag = 0; 401 1.5.2.2 rmind vp->v_vflag = 0; 402 1.5.2.2 rmind vp->v_uflag = 0; 403 1.5.2.2 rmind vp->v_socket = NULL; 404 1.5.2.2 rmind } 405 1.5.2.2 rmind 406 1.5.2.2 rmind KASSERT(vp->v_usecount == 1); 407 1.5.2.2 rmind KASSERT(vp->v_freelisthd == NULL); 408 1.5.2.2 rmind KASSERT(LIST_EMPTY(&vp->v_nclist)); 409 1.5.2.2 rmind KASSERT(LIST_EMPTY(&vp->v_dnclist)); 410 1.5.2.2 rmind 411 1.5.2.2 rmind /* Initialize vnode. */ 412 1.5.2.2 rmind vp->v_type = VNON; 413 1.5.2.2 rmind vp->v_tag = tag; 414 1.5.2.2 rmind vp->v_op = vops; 415 1.5.2.2 rmind vp->v_data = NULL; 416 1.5.2.2 rmind 417 1.5.2.2 rmind uobj = &vp->v_uobj; 418 1.5.2.2 rmind KASSERT(uobj->pgops == &uvm_vnodeops); 419 1.5.2.2 rmind KASSERT(uobj->uo_npages == 0); 420 1.5.2.2 rmind KASSERT(TAILQ_FIRST(&uobj->memq) == NULL); 421 1.5.2.2 rmind vp->v_size = vp->v_writesize = VSIZENOTSET; 422 1.5.2.2 rmind 423 1.5.2.3 rmind /* Share the vnode_t::v_interlock, if requested. */ 424 1.5.2.3 rmind if (svp) { 425 1.5.2.3 rmind /* Set the interlock and mark that it is shared. */ 426 1.5.2.3 rmind KASSERT(vp->v_mount == NULL); 427 1.5.2.3 rmind uvm_obj_setlock(&vp->v_uobj, svp->v_interlock); 428 1.5.2.3 rmind KASSERT(vp->v_interlock == svp->v_interlock); 429 1.5.2.3 rmind vp->v_iflag |= VI_LOCKSHARE; 430 1.5.2.3 rmind } 431 1.5.2.3 rmind 432 1.5.2.2 rmind /* Finally, move vnode into the mount queue. */ 433 1.5.2.2 rmind vfs_insmntque(vp, mp); 434 1.5.2.2 rmind 435 1.5.2.2 rmind if (mp != NULL) { 436 1.5.2.2 rmind if ((mp->mnt_iflag & IMNT_MPSAFE) != 0) 437 1.5.2.2 rmind vp->v_vflag |= VV_MPSAFE; 438 1.5.2.2 rmind vfs_unbusy(mp, true, NULL); 439 1.5.2.2 rmind } 440 1.5.2.2 rmind 441 1.5.2.2 rmind *vpp = vp; 442 1.5.2.2 rmind return 0; 443 1.5.2.2 rmind } 444 1.5.2.2 rmind 445 1.5.2.2 rmind /* 446 1.5.2.2 rmind * This is really just the reverse of getnewvnode(). Needed for 447 1.5.2.2 rmind * VFS_VGET functions who may need to push back a vnode in case 448 1.5.2.2 rmind * of a locking race. 449 1.5.2.2 rmind */ 450 1.5.2.2 rmind void 451 1.5.2.2 rmind ungetnewvnode(vnode_t *vp) 452 1.5.2.2 rmind { 453 1.5.2.2 rmind 454 1.5.2.2 rmind KASSERT(vp->v_usecount == 1); 455 1.5.2.2 rmind KASSERT(vp->v_data == NULL); 456 1.5.2.2 rmind KASSERT(vp->v_freelisthd == NULL); 457 1.5.2.2 rmind 458 1.5.2.2 rmind mutex_enter(vp->v_interlock); 459 1.5.2.2 rmind vp->v_iflag |= VI_CLEAN; 460 1.5.2.2 rmind vrelel(vp, 0); 461 1.5.2.2 rmind } 462 1.5.2.2 rmind 463 1.5.2.2 rmind /* 464 1.5.2.2 rmind * Remove a vnode from its freelist. 465 1.5.2.2 rmind */ 466 1.5.2.2 rmind void 467 1.5.2.2 rmind vremfree(vnode_t *vp) 468 1.5.2.2 rmind { 469 1.5.2.2 rmind 470 1.5.2.2 rmind KASSERT(mutex_owned(vp->v_interlock)); 471 1.5.2.2 rmind KASSERT(vp->v_usecount == 0); 472 1.5.2.2 rmind 473 1.5.2.2 rmind /* 474 1.5.2.2 rmind * Note that the reference count must not change until 475 1.5.2.2 rmind * the vnode is removed. 476 1.5.2.2 rmind */ 477 1.5.2.2 rmind mutex_enter(&vnode_free_list_lock); 478 1.5.2.2 rmind if (vp->v_holdcnt > 0) { 479 1.5.2.2 rmind KASSERT(vp->v_freelisthd == &vnode_hold_list); 480 1.5.2.2 rmind } else { 481 1.5.2.2 rmind KASSERT(vp->v_freelisthd == &vnode_free_list); 482 1.5.2.2 rmind } 483 1.5.2.2 rmind TAILQ_REMOVE(vp->v_freelisthd, vp, v_freelist); 484 1.5.2.2 rmind vp->v_freelisthd = NULL; 485 1.5.2.2 rmind mutex_exit(&vnode_free_list_lock); 486 1.5.2.2 rmind } 487 1.5.2.2 rmind 488 1.5.2.2 rmind /* 489 1.5.2.2 rmind * Try to gain a reference to a vnode, without acquiring its interlock. 490 1.5.2.2 rmind * The caller must hold a lock that will prevent the vnode from being 491 1.5.2.2 rmind * recycled or freed. 492 1.5.2.2 rmind */ 493 1.5.2.2 rmind bool 494 1.5.2.2 rmind vtryget(vnode_t *vp) 495 1.5.2.2 rmind { 496 1.5.2.2 rmind u_int use, next; 497 1.5.2.2 rmind 498 1.5.2.2 rmind /* 499 1.5.2.2 rmind * If the vnode is being freed, don't make life any harder 500 1.5.2.2 rmind * for vclean() by adding another reference without waiting. 501 1.5.2.2 rmind * This is not strictly necessary, but we'll do it anyway. 502 1.5.2.2 rmind */ 503 1.5.2.2 rmind if (__predict_false((vp->v_iflag & VI_XLOCK) != 0)) { 504 1.5.2.2 rmind return false; 505 1.5.2.2 rmind } 506 1.5.2.2 rmind for (use = vp->v_usecount;; use = next) { 507 1.5.2.2 rmind if (use == 0 || __predict_false((use & VC_XLOCK) != 0)) { 508 1.5.2.2 rmind /* Need interlock held if first reference. */ 509 1.5.2.2 rmind return false; 510 1.5.2.2 rmind } 511 1.5.2.2 rmind next = atomic_cas_uint(&vp->v_usecount, use, use + 1); 512 1.5.2.2 rmind if (__predict_true(next == use)) { 513 1.5.2.2 rmind return true; 514 1.5.2.2 rmind } 515 1.5.2.2 rmind } 516 1.5.2.2 rmind } 517 1.5.2.2 rmind 518 1.5.2.2 rmind /* 519 1.5.2.2 rmind * vget: get a particular vnode from the free list, increment its reference 520 1.5.2.2 rmind * count and lock it. 521 1.5.2.2 rmind * 522 1.5.2.2 rmind * => Should be called with v_interlock held. 523 1.5.2.2 rmind * 524 1.5.2.2 rmind * If VI_XLOCK is set, the vnode is being eliminated in vgone()/vclean(). 525 1.5.2.2 rmind * In that case, we cannot grab the vnode, so the process is awakened when 526 1.5.2.2 rmind * the transition is completed, and an error returned to indicate that the 527 1.5.2.2 rmind * vnode is no longer usable (e.g. changed to a new file system type). 528 1.5.2.2 rmind */ 529 1.5.2.2 rmind int 530 1.5.2.2 rmind vget(vnode_t *vp, int flags) 531 1.5.2.2 rmind { 532 1.5.2.2 rmind int error = 0; 533 1.5.2.2 rmind 534 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_MARKER) == 0); 535 1.5.2.2 rmind KASSERT(mutex_owned(vp->v_interlock)); 536 1.5.2.2 rmind KASSERT((flags & ~(LK_SHARED|LK_EXCLUSIVE|LK_NOWAIT)) == 0); 537 1.5.2.2 rmind 538 1.5.2.2 rmind /* 539 1.5.2.2 rmind * Before adding a reference, we must remove the vnode 540 1.5.2.2 rmind * from its freelist. 541 1.5.2.2 rmind */ 542 1.5.2.2 rmind if (vp->v_usecount == 0) { 543 1.5.2.2 rmind vremfree(vp); 544 1.5.2.2 rmind vp->v_usecount = 1; 545 1.5.2.2 rmind } else { 546 1.5.2.2 rmind atomic_inc_uint(&vp->v_usecount); 547 1.5.2.2 rmind } 548 1.5.2.2 rmind 549 1.5.2.2 rmind /* 550 1.5.2.2 rmind * If the vnode is in the process of being cleaned out for 551 1.5.2.2 rmind * another use, we wait for the cleaning to finish and then 552 1.5.2.2 rmind * return failure. Cleaning is determined by checking if 553 1.5.2.2 rmind * the VI_XLOCK flag is set. 554 1.5.2.2 rmind */ 555 1.5.2.2 rmind if ((vp->v_iflag & VI_XLOCK) != 0) { 556 1.5.2.2 rmind if ((flags & LK_NOWAIT) != 0) { 557 1.5.2.2 rmind vrelel(vp, 0); 558 1.5.2.2 rmind return EBUSY; 559 1.5.2.2 rmind } 560 1.5.2.2 rmind vwait(vp, VI_XLOCK); 561 1.5.2.2 rmind vrelel(vp, 0); 562 1.5.2.2 rmind return ENOENT; 563 1.5.2.2 rmind } 564 1.5.2.2 rmind 565 1.5.2.2 rmind /* 566 1.5.2.2 rmind * Ok, we got it in good shape. Just locking left. 567 1.5.2.2 rmind */ 568 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_CLEAN) == 0); 569 1.5.2.2 rmind mutex_exit(vp->v_interlock); 570 1.5.2.2 rmind if (flags & (LK_EXCLUSIVE | LK_SHARED)) { 571 1.5.2.2 rmind error = vn_lock(vp, flags); 572 1.5.2.2 rmind if (error != 0) { 573 1.5.2.2 rmind vrele(vp); 574 1.5.2.2 rmind } 575 1.5.2.2 rmind } 576 1.5.2.2 rmind return error; 577 1.5.2.2 rmind } 578 1.5.2.2 rmind 579 1.5.2.2 rmind /* 580 1.5.2.2 rmind * vput: unlock and release the reference. 581 1.5.2.2 rmind */ 582 1.5.2.2 rmind void 583 1.5.2.2 rmind vput(vnode_t *vp) 584 1.5.2.2 rmind { 585 1.5.2.2 rmind 586 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_MARKER) == 0); 587 1.5.2.2 rmind 588 1.5.2.2 rmind VOP_UNLOCK(vp); 589 1.5.2.2 rmind vrele(vp); 590 1.5.2.2 rmind } 591 1.5.2.2 rmind 592 1.5.2.2 rmind /* 593 1.5.2.2 rmind * Try to drop reference on a vnode. Abort if we are releasing the 594 1.5.2.2 rmind * last reference. Note: this _must_ succeed if not the last reference. 595 1.5.2.2 rmind */ 596 1.5.2.2 rmind static inline bool 597 1.5.2.2 rmind vtryrele(vnode_t *vp) 598 1.5.2.2 rmind { 599 1.5.2.2 rmind u_int use, next; 600 1.5.2.2 rmind 601 1.5.2.2 rmind for (use = vp->v_usecount;; use = next) { 602 1.5.2.2 rmind if (use == 1) { 603 1.5.2.2 rmind return false; 604 1.5.2.2 rmind } 605 1.5.2.2 rmind KASSERT((use & VC_MASK) > 1); 606 1.5.2.2 rmind next = atomic_cas_uint(&vp->v_usecount, use, use - 1); 607 1.5.2.2 rmind if (__predict_true(next == use)) { 608 1.5.2.2 rmind return true; 609 1.5.2.2 rmind } 610 1.5.2.2 rmind } 611 1.5.2.2 rmind } 612 1.5.2.2 rmind 613 1.5.2.2 rmind /* 614 1.5.2.2 rmind * Vnode release. If reference count drops to zero, call inactive 615 1.5.2.2 rmind * routine and either return to freelist or free to the pool. 616 1.5.2.2 rmind */ 617 1.5.2.2 rmind void 618 1.5.2.2 rmind vrelel(vnode_t *vp, int flags) 619 1.5.2.2 rmind { 620 1.5.2.2 rmind bool recycle, defer; 621 1.5.2.2 rmind int error; 622 1.5.2.2 rmind 623 1.5.2.2 rmind KASSERT(mutex_owned(vp->v_interlock)); 624 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_MARKER) == 0); 625 1.5.2.2 rmind KASSERT(vp->v_freelisthd == NULL); 626 1.5.2.2 rmind 627 1.5.2.2 rmind if (__predict_false(vp->v_op == dead_vnodeop_p && 628 1.5.2.2 rmind (vp->v_iflag & (VI_CLEAN|VI_XLOCK)) == 0)) { 629 1.5.2.2 rmind vpanic(vp, "dead but not clean"); 630 1.5.2.2 rmind } 631 1.5.2.2 rmind 632 1.5.2.2 rmind /* 633 1.5.2.2 rmind * If not the last reference, just drop the reference count 634 1.5.2.2 rmind * and unlock. 635 1.5.2.2 rmind */ 636 1.5.2.2 rmind if (vtryrele(vp)) { 637 1.5.2.2 rmind vp->v_iflag |= VI_INACTREDO; 638 1.5.2.2 rmind mutex_exit(vp->v_interlock); 639 1.5.2.2 rmind return; 640 1.5.2.2 rmind } 641 1.5.2.2 rmind if (vp->v_usecount <= 0 || vp->v_writecount != 0) { 642 1.5.2.2 rmind vpanic(vp, "vrelel: bad ref count"); 643 1.5.2.2 rmind } 644 1.5.2.2 rmind 645 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_XLOCK) == 0); 646 1.5.2.2 rmind 647 1.5.2.2 rmind /* 648 1.5.2.2 rmind * If not clean, deactivate the vnode, but preserve 649 1.5.2.2 rmind * our reference across the call to VOP_INACTIVE(). 650 1.5.2.2 rmind */ 651 1.5.2.2 rmind retry: 652 1.5.2.2 rmind if ((vp->v_iflag & VI_CLEAN) == 0) { 653 1.5.2.2 rmind recycle = false; 654 1.5.2.2 rmind vp->v_iflag |= VI_INACTNOW; 655 1.5.2.2 rmind 656 1.5.2.2 rmind /* 657 1.5.2.2 rmind * XXX This ugly block can be largely eliminated if 658 1.5.2.2 rmind * locking is pushed down into the file systems. 659 1.5.2.2 rmind * 660 1.5.2.2 rmind * Defer vnode release to vrele_thread if caller 661 1.5.2.2 rmind * requests it explicitly. 662 1.5.2.2 rmind */ 663 1.5.2.2 rmind if ((curlwp == uvm.pagedaemon_lwp) || 664 1.5.2.2 rmind (flags & VRELEL_ASYNC_RELE) != 0) { 665 1.5.2.2 rmind /* The pagedaemon can't wait around; defer. */ 666 1.5.2.2 rmind defer = true; 667 1.5.2.2 rmind } else if (curlwp == vrele_lwp) { 668 1.5.2.2 rmind /* We have to try harder. */ 669 1.5.2.2 rmind vp->v_iflag &= ~VI_INACTREDO; 670 1.5.2.2 rmind mutex_exit(vp->v_interlock); 671 1.5.2.2 rmind error = vn_lock(vp, LK_EXCLUSIVE); 672 1.5.2.2 rmind if (error != 0) { 673 1.5.2.2 rmind /* XXX */ 674 1.5.2.2 rmind vpanic(vp, "vrele: unable to lock %p"); 675 1.5.2.2 rmind } 676 1.5.2.2 rmind defer = false; 677 1.5.2.2 rmind } else if ((vp->v_iflag & VI_LAYER) != 0) { 678 1.5.2.2 rmind /* 679 1.5.2.2 rmind * Acquiring the stack's lock in vclean() even 680 1.5.2.2 rmind * for an honest vput/vrele is dangerous because 681 1.5.2.2 rmind * our caller may hold other vnode locks; defer. 682 1.5.2.2 rmind */ 683 1.5.2.2 rmind defer = true; 684 1.5.2.2 rmind } else { 685 1.5.2.2 rmind /* If we can't acquire the lock, then defer. */ 686 1.5.2.2 rmind vp->v_iflag &= ~VI_INACTREDO; 687 1.5.2.2 rmind mutex_exit(vp->v_interlock); 688 1.5.2.2 rmind error = vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT); 689 1.5.2.2 rmind if (error != 0) { 690 1.5.2.2 rmind defer = true; 691 1.5.2.2 rmind mutex_enter(vp->v_interlock); 692 1.5.2.2 rmind } else { 693 1.5.2.2 rmind defer = false; 694 1.5.2.2 rmind } 695 1.5.2.2 rmind } 696 1.5.2.2 rmind 697 1.5.2.2 rmind if (defer) { 698 1.5.2.2 rmind /* 699 1.5.2.2 rmind * Defer reclaim to the kthread; it's not safe to 700 1.5.2.2 rmind * clean it here. We donate it our last reference. 701 1.5.2.2 rmind */ 702 1.5.2.2 rmind KASSERT(mutex_owned(vp->v_interlock)); 703 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_INACTPEND) == 0); 704 1.5.2.2 rmind vp->v_iflag &= ~VI_INACTNOW; 705 1.5.2.2 rmind vp->v_iflag |= VI_INACTPEND; 706 1.5.2.2 rmind mutex_enter(&vrele_lock); 707 1.5.2.2 rmind TAILQ_INSERT_TAIL(&vrele_list, vp, v_freelist); 708 1.5.2.2 rmind if (++vrele_pending > (desiredvnodes >> 8)) 709 1.5.2.2 rmind cv_signal(&vrele_cv); 710 1.5.2.2 rmind mutex_exit(&vrele_lock); 711 1.5.2.2 rmind mutex_exit(vp->v_interlock); 712 1.5.2.2 rmind return; 713 1.5.2.2 rmind } 714 1.5.2.2 rmind 715 1.5.2.2 rmind #ifdef DIAGNOSTIC 716 1.5.2.2 rmind if ((vp->v_type == VBLK || vp->v_type == VCHR) && 717 1.5.2.2 rmind vp->v_specnode != NULL && vp->v_specnode->sn_opencnt != 0) { 718 1.5.2.2 rmind vprint("vrelel: missing VOP_CLOSE()", vp); 719 1.5.2.2 rmind } 720 1.5.2.2 rmind #endif 721 1.5.2.2 rmind 722 1.5.2.2 rmind /* 723 1.5.2.2 rmind * The vnode can gain another reference while being 724 1.5.2.2 rmind * deactivated. If VOP_INACTIVE() indicates that 725 1.5.2.2 rmind * the described file has been deleted, then recycle 726 1.5.2.2 rmind * the vnode irrespective of additional references. 727 1.5.2.2 rmind * Another thread may be waiting to re-use the on-disk 728 1.5.2.2 rmind * inode. 729 1.5.2.2 rmind * 730 1.5.2.2 rmind * Note that VOP_INACTIVE() will drop the vnode lock. 731 1.5.2.2 rmind */ 732 1.5.2.2 rmind VOP_INACTIVE(vp, &recycle); 733 1.5.2.2 rmind mutex_enter(vp->v_interlock); 734 1.5.2.2 rmind vp->v_iflag &= ~VI_INACTNOW; 735 1.5.2.2 rmind if (!recycle) { 736 1.5.2.2 rmind if (vtryrele(vp)) { 737 1.5.2.2 rmind mutex_exit(vp->v_interlock); 738 1.5.2.2 rmind return; 739 1.5.2.2 rmind } 740 1.5.2.2 rmind 741 1.5.2.2 rmind /* 742 1.5.2.2 rmind * If we grew another reference while 743 1.5.2.2 rmind * VOP_INACTIVE() was underway, retry. 744 1.5.2.2 rmind */ 745 1.5.2.2 rmind if ((vp->v_iflag & VI_INACTREDO) != 0) { 746 1.5.2.2 rmind goto retry; 747 1.5.2.2 rmind } 748 1.5.2.2 rmind } 749 1.5.2.2 rmind 750 1.5.2.2 rmind /* Take care of space accounting. */ 751 1.5.2.2 rmind if (vp->v_iflag & VI_EXECMAP) { 752 1.5.2.2 rmind atomic_add_int(&uvmexp.execpages, 753 1.5.2.2 rmind -vp->v_uobj.uo_npages); 754 1.5.2.2 rmind atomic_add_int(&uvmexp.filepages, 755 1.5.2.2 rmind vp->v_uobj.uo_npages); 756 1.5.2.2 rmind } 757 1.5.2.2 rmind vp->v_iflag &= ~(VI_TEXT|VI_EXECMAP|VI_WRMAP); 758 1.5.2.2 rmind vp->v_vflag &= ~VV_MAPPED; 759 1.5.2.2 rmind 760 1.5.2.2 rmind /* 761 1.5.2.2 rmind * Recycle the vnode if the file is now unused (unlinked), 762 1.5.2.2 rmind * otherwise just free it. 763 1.5.2.2 rmind */ 764 1.5.2.2 rmind if (recycle) { 765 1.5.2.2 rmind vclean(vp, DOCLOSE); 766 1.5.2.2 rmind } 767 1.5.2.2 rmind KASSERT(vp->v_usecount > 0); 768 1.5.2.2 rmind } 769 1.5.2.2 rmind 770 1.5.2.2 rmind if (atomic_dec_uint_nv(&vp->v_usecount) != 0) { 771 1.5.2.2 rmind /* Gained another reference while being reclaimed. */ 772 1.5.2.2 rmind mutex_exit(vp->v_interlock); 773 1.5.2.2 rmind return; 774 1.5.2.2 rmind } 775 1.5.2.2 rmind 776 1.5.2.2 rmind if ((vp->v_iflag & VI_CLEAN) != 0) { 777 1.5.2.2 rmind /* 778 1.5.2.2 rmind * It's clean so destroy it. It isn't referenced 779 1.5.2.2 rmind * anywhere since it has been reclaimed. 780 1.5.2.2 rmind */ 781 1.5.2.2 rmind KASSERT(vp->v_holdcnt == 0); 782 1.5.2.2 rmind KASSERT(vp->v_writecount == 0); 783 1.5.2.2 rmind mutex_exit(vp->v_interlock); 784 1.5.2.2 rmind vfs_insmntque(vp, NULL); 785 1.5.2.2 rmind if (vp->v_type == VBLK || vp->v_type == VCHR) { 786 1.5.2.2 rmind spec_node_destroy(vp); 787 1.5.2.2 rmind } 788 1.5.2.2 rmind vnfree(vp); 789 1.5.2.2 rmind } else { 790 1.5.2.2 rmind /* 791 1.5.2.2 rmind * Otherwise, put it back onto the freelist. It 792 1.5.2.2 rmind * can't be destroyed while still associated with 793 1.5.2.2 rmind * a file system. 794 1.5.2.2 rmind */ 795 1.5.2.2 rmind mutex_enter(&vnode_free_list_lock); 796 1.5.2.2 rmind if (vp->v_holdcnt > 0) { 797 1.5.2.2 rmind vp->v_freelisthd = &vnode_hold_list; 798 1.5.2.2 rmind } else { 799 1.5.2.2 rmind vp->v_freelisthd = &vnode_free_list; 800 1.5.2.2 rmind } 801 1.5.2.2 rmind TAILQ_INSERT_TAIL(vp->v_freelisthd, vp, v_freelist); 802 1.5.2.2 rmind mutex_exit(&vnode_free_list_lock); 803 1.5.2.2 rmind mutex_exit(vp->v_interlock); 804 1.5.2.2 rmind } 805 1.5.2.2 rmind } 806 1.5.2.2 rmind 807 1.5.2.2 rmind void 808 1.5.2.2 rmind vrele(vnode_t *vp) 809 1.5.2.2 rmind { 810 1.5.2.2 rmind 811 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_MARKER) == 0); 812 1.5.2.2 rmind 813 1.5.2.2 rmind if ((vp->v_iflag & VI_INACTNOW) == 0 && vtryrele(vp)) { 814 1.5.2.2 rmind return; 815 1.5.2.2 rmind } 816 1.5.2.2 rmind mutex_enter(vp->v_interlock); 817 1.5.2.2 rmind vrelel(vp, 0); 818 1.5.2.2 rmind } 819 1.5.2.2 rmind 820 1.5.2.2 rmind /* 821 1.5.2.2 rmind * Asynchronous vnode release, vnode is released in different context. 822 1.5.2.2 rmind */ 823 1.5.2.2 rmind void 824 1.5.2.2 rmind vrele_async(vnode_t *vp) 825 1.5.2.2 rmind { 826 1.5.2.2 rmind 827 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_MARKER) == 0); 828 1.5.2.2 rmind 829 1.5.2.2 rmind if ((vp->v_iflag & VI_INACTNOW) == 0 && vtryrele(vp)) { 830 1.5.2.2 rmind return; 831 1.5.2.2 rmind } 832 1.5.2.2 rmind mutex_enter(vp->v_interlock); 833 1.5.2.2 rmind vrelel(vp, VRELEL_ASYNC_RELE); 834 1.5.2.2 rmind } 835 1.5.2.2 rmind 836 1.5.2.2 rmind static void 837 1.5.2.2 rmind vrele_thread(void *cookie) 838 1.5.2.2 rmind { 839 1.5.2.2 rmind vnode_t *vp; 840 1.5.2.2 rmind 841 1.5.2.2 rmind for (;;) { 842 1.5.2.2 rmind mutex_enter(&vrele_lock); 843 1.5.2.2 rmind while (TAILQ_EMPTY(&vrele_list)) { 844 1.5.2.2 rmind vrele_gen++; 845 1.5.2.2 rmind cv_broadcast(&vrele_cv); 846 1.5.2.2 rmind cv_timedwait(&vrele_cv, &vrele_lock, hz); 847 1.5.2.2 rmind } 848 1.5.2.2 rmind vp = TAILQ_FIRST(&vrele_list); 849 1.5.2.2 rmind TAILQ_REMOVE(&vrele_list, vp, v_freelist); 850 1.5.2.2 rmind vrele_pending--; 851 1.5.2.2 rmind mutex_exit(&vrele_lock); 852 1.5.2.2 rmind 853 1.5.2.2 rmind /* 854 1.5.2.2 rmind * If not the last reference, then ignore the vnode 855 1.5.2.2 rmind * and look for more work. 856 1.5.2.2 rmind */ 857 1.5.2.2 rmind mutex_enter(vp->v_interlock); 858 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_INACTPEND) != 0); 859 1.5.2.2 rmind vp->v_iflag &= ~VI_INACTPEND; 860 1.5.2.2 rmind vrelel(vp, 0); 861 1.5.2.2 rmind } 862 1.5.2.2 rmind } 863 1.5.2.2 rmind 864 1.5.2.2 rmind void 865 1.5.2.2 rmind vrele_flush(void) 866 1.5.2.2 rmind { 867 1.5.2.2 rmind int gen; 868 1.5.2.2 rmind 869 1.5.2.2 rmind mutex_enter(&vrele_lock); 870 1.5.2.2 rmind gen = vrele_gen; 871 1.5.2.2 rmind while (vrele_pending && gen == vrele_gen) { 872 1.5.2.2 rmind cv_broadcast(&vrele_cv); 873 1.5.2.2 rmind cv_wait(&vrele_cv, &vrele_lock); 874 1.5.2.2 rmind } 875 1.5.2.2 rmind mutex_exit(&vrele_lock); 876 1.5.2.2 rmind } 877 1.5.2.2 rmind 878 1.5.2.2 rmind /* 879 1.5.2.2 rmind * Vnode reference, where a reference is already held by some other 880 1.5.2.2 rmind * object (for example, a file structure). 881 1.5.2.2 rmind */ 882 1.5.2.2 rmind void 883 1.5.2.2 rmind vref(vnode_t *vp) 884 1.5.2.2 rmind { 885 1.5.2.2 rmind 886 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_MARKER) == 0); 887 1.5.2.2 rmind KASSERT(vp->v_usecount != 0); 888 1.5.2.2 rmind 889 1.5.2.2 rmind atomic_inc_uint(&vp->v_usecount); 890 1.5.2.2 rmind } 891 1.5.2.2 rmind 892 1.5.2.2 rmind /* 893 1.5.2.2 rmind * Page or buffer structure gets a reference. 894 1.5.2.2 rmind * Called with v_interlock held. 895 1.5.2.2 rmind */ 896 1.5.2.2 rmind void 897 1.5.2.2 rmind vholdl(vnode_t *vp) 898 1.5.2.2 rmind { 899 1.5.2.2 rmind 900 1.5.2.2 rmind KASSERT(mutex_owned(vp->v_interlock)); 901 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_MARKER) == 0); 902 1.5.2.2 rmind 903 1.5.2.2 rmind if (vp->v_holdcnt++ == 0 && vp->v_usecount == 0) { 904 1.5.2.2 rmind mutex_enter(&vnode_free_list_lock); 905 1.5.2.2 rmind KASSERT(vp->v_freelisthd == &vnode_free_list); 906 1.5.2.2 rmind TAILQ_REMOVE(vp->v_freelisthd, vp, v_freelist); 907 1.5.2.2 rmind vp->v_freelisthd = &vnode_hold_list; 908 1.5.2.2 rmind TAILQ_INSERT_TAIL(vp->v_freelisthd, vp, v_freelist); 909 1.5.2.2 rmind mutex_exit(&vnode_free_list_lock); 910 1.5.2.2 rmind } 911 1.5.2.2 rmind } 912 1.5.2.2 rmind 913 1.5.2.2 rmind /* 914 1.5.2.2 rmind * Page or buffer structure frees a reference. 915 1.5.2.2 rmind * Called with v_interlock held. 916 1.5.2.2 rmind */ 917 1.5.2.2 rmind void 918 1.5.2.2 rmind holdrelel(vnode_t *vp) 919 1.5.2.2 rmind { 920 1.5.2.2 rmind 921 1.5.2.2 rmind KASSERT(mutex_owned(vp->v_interlock)); 922 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_MARKER) == 0); 923 1.5.2.2 rmind 924 1.5.2.2 rmind if (vp->v_holdcnt <= 0) { 925 1.5.2.2 rmind vpanic(vp, "holdrelel: holdcnt vp %p"); 926 1.5.2.2 rmind } 927 1.5.2.2 rmind 928 1.5.2.2 rmind vp->v_holdcnt--; 929 1.5.2.2 rmind if (vp->v_holdcnt == 0 && vp->v_usecount == 0) { 930 1.5.2.2 rmind mutex_enter(&vnode_free_list_lock); 931 1.5.2.2 rmind KASSERT(vp->v_freelisthd == &vnode_hold_list); 932 1.5.2.2 rmind TAILQ_REMOVE(vp->v_freelisthd, vp, v_freelist); 933 1.5.2.2 rmind vp->v_freelisthd = &vnode_free_list; 934 1.5.2.2 rmind TAILQ_INSERT_TAIL(vp->v_freelisthd, vp, v_freelist); 935 1.5.2.2 rmind mutex_exit(&vnode_free_list_lock); 936 1.5.2.2 rmind } 937 1.5.2.2 rmind } 938 1.5.2.2 rmind 939 1.5.2.2 rmind /* 940 1.5.2.2 rmind * Disassociate the underlying file system from a vnode. 941 1.5.2.2 rmind * 942 1.5.2.2 rmind * Must be called with the interlock held, and will return with it held. 943 1.5.2.2 rmind */ 944 1.5.2.2 rmind void 945 1.5.2.2 rmind vclean(vnode_t *vp, int flags) 946 1.5.2.2 rmind { 947 1.5.2.2 rmind lwp_t *l = curlwp; 948 1.5.2.2 rmind bool recycle, active; 949 1.5.2.2 rmind int error; 950 1.5.2.2 rmind 951 1.5.2.2 rmind KASSERT(mutex_owned(vp->v_interlock)); 952 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_MARKER) == 0); 953 1.5.2.2 rmind KASSERT(vp->v_usecount != 0); 954 1.5.2.2 rmind 955 1.5.2.2 rmind /* If cleaning is already in progress wait until done and return. */ 956 1.5.2.2 rmind if (vp->v_iflag & VI_XLOCK) { 957 1.5.2.2 rmind vwait(vp, VI_XLOCK); 958 1.5.2.2 rmind return; 959 1.5.2.2 rmind } 960 1.5.2.2 rmind 961 1.5.2.2 rmind /* If already clean, nothing to do. */ 962 1.5.2.2 rmind if ((vp->v_iflag & VI_CLEAN) != 0) { 963 1.5.2.2 rmind return; 964 1.5.2.2 rmind } 965 1.5.2.2 rmind 966 1.5.2.2 rmind /* 967 1.5.2.2 rmind * Prevent the vnode from being recycled or brought into use 968 1.5.2.2 rmind * while we clean it out. 969 1.5.2.2 rmind */ 970 1.5.2.2 rmind vp->v_iflag |= VI_XLOCK; 971 1.5.2.2 rmind if (vp->v_iflag & VI_EXECMAP) { 972 1.5.2.2 rmind atomic_add_int(&uvmexp.execpages, -vp->v_uobj.uo_npages); 973 1.5.2.2 rmind atomic_add_int(&uvmexp.filepages, vp->v_uobj.uo_npages); 974 1.5.2.2 rmind } 975 1.5.2.2 rmind vp->v_iflag &= ~(VI_TEXT|VI_EXECMAP); 976 1.5.2.2 rmind active = (vp->v_usecount & VC_MASK) > 1; 977 1.5.2.2 rmind 978 1.5.2.2 rmind /* XXXAD should not lock vnode under layer */ 979 1.5.2.2 rmind mutex_exit(vp->v_interlock); 980 1.5.2.2 rmind VOP_LOCK(vp, LK_EXCLUSIVE); 981 1.5.2.2 rmind 982 1.5.2.2 rmind /* 983 1.5.2.2 rmind * Clean out any cached data associated with the vnode. 984 1.5.2.2 rmind * If purging an active vnode, it must be closed and 985 1.5.2.2 rmind * deactivated before being reclaimed. Note that the 986 1.5.2.2 rmind * VOP_INACTIVE will unlock the vnode. 987 1.5.2.2 rmind */ 988 1.5.2.2 rmind if (flags & DOCLOSE) { 989 1.5.2.2 rmind error = vinvalbuf(vp, V_SAVE, NOCRED, l, 0, 0); 990 1.5.2.2 rmind if (error != 0) { 991 1.5.2.2 rmind /* XXX, fix vn_start_write's grab of mp and use that. */ 992 1.5.2.2 rmind 993 1.5.2.2 rmind if (wapbl_vphaswapbl(vp)) 994 1.5.2.2 rmind WAPBL_DISCARD(wapbl_vptomp(vp)); 995 1.5.2.2 rmind error = vinvalbuf(vp, 0, NOCRED, l, 0, 0); 996 1.5.2.2 rmind } 997 1.5.2.2 rmind KASSERT(error == 0); 998 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_ONWORKLST) == 0); 999 1.5.2.2 rmind if (active && (vp->v_type == VBLK || vp->v_type == VCHR)) { 1000 1.5.2.2 rmind spec_node_revoke(vp); 1001 1.5.2.2 rmind } 1002 1.5.2.2 rmind } 1003 1.5.2.2 rmind if (active) { 1004 1.5.2.2 rmind VOP_INACTIVE(vp, &recycle); 1005 1.5.2.2 rmind } else { 1006 1.5.2.2 rmind /* 1007 1.5.2.2 rmind * Any other processes trying to obtain this lock must first 1008 1.5.2.2 rmind * wait for VI_XLOCK to clear, then call the new lock operation. 1009 1.5.2.2 rmind */ 1010 1.5.2.2 rmind VOP_UNLOCK(vp); 1011 1.5.2.2 rmind } 1012 1.5.2.2 rmind 1013 1.5.2.2 rmind /* Disassociate the underlying file system from the vnode. */ 1014 1.5.2.2 rmind if (VOP_RECLAIM(vp)) { 1015 1.5.2.2 rmind vpanic(vp, "vclean: cannot reclaim"); 1016 1.5.2.2 rmind } 1017 1.5.2.2 rmind 1018 1.5.2.2 rmind KASSERT(vp->v_uobj.uo_npages == 0); 1019 1.5.2.2 rmind if (vp->v_type == VREG && vp->v_ractx != NULL) { 1020 1.5.2.2 rmind uvm_ra_freectx(vp->v_ractx); 1021 1.5.2.2 rmind vp->v_ractx = NULL; 1022 1.5.2.2 rmind } 1023 1.5.2.2 rmind cache_purge(vp); 1024 1.5.2.2 rmind 1025 1.5.2.2 rmind /* Done with purge, notify sleepers of the grim news. */ 1026 1.5.2.2 rmind mutex_enter(vp->v_interlock); 1027 1.5.2.2 rmind vp->v_op = dead_vnodeop_p; 1028 1.5.2.2 rmind vp->v_tag = VT_NON; 1029 1.5.2.2 rmind KNOTE(&vp->v_klist, NOTE_REVOKE); 1030 1.5.2.2 rmind vp->v_iflag &= ~VI_XLOCK; 1031 1.5.2.2 rmind vp->v_vflag &= ~VV_LOCKSWORK; 1032 1.5.2.2 rmind if ((flags & DOCLOSE) != 0) { 1033 1.5.2.2 rmind vp->v_iflag |= VI_CLEAN; 1034 1.5.2.2 rmind } 1035 1.5.2.2 rmind cv_broadcast(&vp->v_cv); 1036 1.5.2.2 rmind 1037 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_ONWORKLST) == 0); 1038 1.5.2.2 rmind } 1039 1.5.2.2 rmind 1040 1.5.2.2 rmind /* 1041 1.5.2.2 rmind * Recycle an unused vnode to the front of the free list. 1042 1.5.2.2 rmind * Release the passed interlock if the vnode will be recycled. 1043 1.5.2.2 rmind */ 1044 1.5.2.2 rmind int 1045 1.5.2.2 rmind vrecycle(vnode_t *vp, kmutex_t *inter_lkp, struct lwp *l) 1046 1.5.2.2 rmind { 1047 1.5.2.2 rmind 1048 1.5.2.2 rmind KASSERT((vp->v_iflag & VI_MARKER) == 0); 1049 1.5.2.2 rmind 1050 1.5.2.2 rmind mutex_enter(vp->v_interlock); 1051 1.5.2.2 rmind if (vp->v_usecount != 0) { 1052 1.5.2.2 rmind mutex_exit(vp->v_interlock); 1053 1.5.2.2 rmind return 0; 1054 1.5.2.2 rmind } 1055 1.5.2.2 rmind if (inter_lkp) { 1056 1.5.2.2 rmind mutex_exit(inter_lkp); 1057 1.5.2.2 rmind } 1058 1.5.2.2 rmind vremfree(vp); 1059 1.5.2.2 rmind vp->v_usecount = 1; 1060 1.5.2.2 rmind vclean(vp, DOCLOSE); 1061 1.5.2.2 rmind vrelel(vp, 0); 1062 1.5.2.2 rmind return 1; 1063 1.5.2.2 rmind } 1064 1.5.2.2 rmind 1065 1.5.2.2 rmind /* 1066 1.5.2.2 rmind * Eliminate all activity associated with the requested vnode 1067 1.5.2.2 rmind * and with all vnodes aliased to the requested vnode. 1068 1.5.2.2 rmind */ 1069 1.5.2.2 rmind void 1070 1.5.2.2 rmind vrevoke(vnode_t *vp) 1071 1.5.2.2 rmind { 1072 1.5.2.2 rmind vnode_t *vq, **vpp; 1073 1.5.2.2 rmind enum vtype type; 1074 1.5.2.2 rmind dev_t dev; 1075 1.5.2.2 rmind 1076 1.5.2.2 rmind KASSERT(vp->v_usecount > 0); 1077 1.5.2.2 rmind 1078 1.5.2.2 rmind mutex_enter(vp->v_interlock); 1079 1.5.2.2 rmind if ((vp->v_iflag & VI_CLEAN) != 0) { 1080 1.5.2.2 rmind mutex_exit(vp->v_interlock); 1081 1.5.2.2 rmind return; 1082 1.5.2.2 rmind } else if (vp->v_type != VBLK && vp->v_type != VCHR) { 1083 1.5.2.2 rmind atomic_inc_uint(&vp->v_usecount); 1084 1.5.2.2 rmind vclean(vp, DOCLOSE); 1085 1.5.2.2 rmind vrelel(vp, 0); 1086 1.5.2.2 rmind return; 1087 1.5.2.2 rmind } else { 1088 1.5.2.2 rmind dev = vp->v_rdev; 1089 1.5.2.2 rmind type = vp->v_type; 1090 1.5.2.2 rmind mutex_exit(vp->v_interlock); 1091 1.5.2.2 rmind } 1092 1.5.2.2 rmind 1093 1.5.2.2 rmind vpp = &specfs_hash[SPECHASH(dev)]; 1094 1.5.2.2 rmind mutex_enter(&device_lock); 1095 1.5.2.2 rmind for (vq = *vpp; vq != NULL;) { 1096 1.5.2.2 rmind /* If clean or being cleaned, then ignore it. */ 1097 1.5.2.2 rmind mutex_enter(vq->v_interlock); 1098 1.5.2.2 rmind if ((vq->v_iflag & (VI_CLEAN | VI_XLOCK)) != 0 || 1099 1.5.2.2 rmind vq->v_rdev != dev || vq->v_type != type) { 1100 1.5.2.2 rmind mutex_exit(vq->v_interlock); 1101 1.5.2.2 rmind vq = vq->v_specnext; 1102 1.5.2.2 rmind continue; 1103 1.5.2.2 rmind } 1104 1.5.2.2 rmind mutex_exit(&device_lock); 1105 1.5.2.2 rmind if (vq->v_usecount == 0) { 1106 1.5.2.2 rmind vremfree(vq); 1107 1.5.2.2 rmind vq->v_usecount = 1; 1108 1.5.2.2 rmind } else { 1109 1.5.2.2 rmind atomic_inc_uint(&vq->v_usecount); 1110 1.5.2.2 rmind } 1111 1.5.2.2 rmind vclean(vq, DOCLOSE); 1112 1.5.2.2 rmind vrelel(vq, 0); 1113 1.5.2.2 rmind mutex_enter(&device_lock); 1114 1.5.2.2 rmind vq = *vpp; 1115 1.5.2.2 rmind } 1116 1.5.2.2 rmind mutex_exit(&device_lock); 1117 1.5.2.2 rmind } 1118 1.5.2.2 rmind 1119 1.5.2.2 rmind /* 1120 1.5.2.2 rmind * Eliminate all activity associated with a vnode in preparation for 1121 1.5.2.2 rmind * reuse. Drops a reference from the vnode. 1122 1.5.2.2 rmind */ 1123 1.5.2.2 rmind void 1124 1.5.2.2 rmind vgone(vnode_t *vp) 1125 1.5.2.2 rmind { 1126 1.5.2.2 rmind 1127 1.5.2.2 rmind mutex_enter(vp->v_interlock); 1128 1.5.2.2 rmind vclean(vp, DOCLOSE); 1129 1.5.2.2 rmind vrelel(vp, 0); 1130 1.5.2.2 rmind } 1131 1.5.2.2 rmind 1132 1.5.2.2 rmind /* 1133 1.5.2.2 rmind * Update outstanding I/O count and do wakeup if requested. 1134 1.5.2.2 rmind */ 1135 1.5.2.2 rmind void 1136 1.5.2.2 rmind vwakeup(struct buf *bp) 1137 1.5.2.2 rmind { 1138 1.5.2.2 rmind vnode_t *vp; 1139 1.5.2.2 rmind 1140 1.5.2.2 rmind if ((vp = bp->b_vp) == NULL) 1141 1.5.2.2 rmind return; 1142 1.5.2.2 rmind 1143 1.5.2.2 rmind KASSERT(bp->b_objlock == vp->v_interlock); 1144 1.5.2.2 rmind KASSERT(mutex_owned(bp->b_objlock)); 1145 1.5.2.2 rmind 1146 1.5.2.2 rmind if (--vp->v_numoutput < 0) 1147 1.5.2.2 rmind panic("vwakeup: neg numoutput, vp %p", vp); 1148 1.5.2.2 rmind if (vp->v_numoutput == 0) 1149 1.5.2.2 rmind cv_broadcast(&vp->v_cv); 1150 1.5.2.2 rmind } 1151 1.5.2.2 rmind 1152 1.5.2.2 rmind /* 1153 1.5.2.2 rmind * Wait for a vnode (typically with VI_XLOCK set) to be cleaned or 1154 1.5.2.2 rmind * recycled. 1155 1.5.2.2 rmind */ 1156 1.5.2.2 rmind void 1157 1.5.2.2 rmind vwait(vnode_t *vp, int flags) 1158 1.5.2.2 rmind { 1159 1.5.2.2 rmind 1160 1.5.2.2 rmind KASSERT(mutex_owned(vp->v_interlock)); 1161 1.5.2.2 rmind KASSERT(vp->v_usecount != 0); 1162 1.5.2.2 rmind 1163 1.5.2.2 rmind while ((vp->v_iflag & flags) != 0) 1164 1.5.2.2 rmind cv_wait(&vp->v_cv, vp->v_interlock); 1165 1.5.2.2 rmind } 1166 1.5.2.2 rmind 1167 1.5.2.2 rmind int 1168 1.5.2.2 rmind vfs_drainvnodes(long target) 1169 1.5.2.2 rmind { 1170 1.5.2.2 rmind 1171 1.5.2.2 rmind while (numvnodes > target) { 1172 1.5.2.2 rmind vnode_t *vp; 1173 1.5.2.2 rmind 1174 1.5.2.2 rmind mutex_enter(&vnode_free_list_lock); 1175 1.5.2.2 rmind vp = getcleanvnode(); 1176 1.5.2.2 rmind if (vp == NULL) { 1177 1.5.2.2 rmind return EBUSY; 1178 1.5.2.2 rmind } 1179 1.5.2.2 rmind ungetnewvnode(vp); 1180 1.5.2.2 rmind } 1181 1.5.2.2 rmind return 0; 1182 1.5.2.2 rmind } 1183 1.5.2.2 rmind 1184 1.5.2.2 rmind void 1185 1.5.2.2 rmind vpanic(vnode_t *vp, const char *msg) 1186 1.5.2.2 rmind { 1187 1.5.2.2 rmind #ifdef DIAGNOSTIC 1188 1.5.2.2 rmind 1189 1.5.2.2 rmind vprint(NULL, vp); 1190 1.5.2.2 rmind panic("%s\n", msg); 1191 1.5.2.2 rmind #endif 1192 1.5.2.2 rmind } 1193
Indexes created Sat Sep 20 22:09:52 GMT 2025