kern_alq.c revision 116182
1103785Sjeff/* 2103785Sjeff * Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org> 3103785Sjeff * All rights reserved. 4103785Sjeff * 5103785Sjeff * Redistribution and use in source and binary forms, with or without 6103785Sjeff * modification, are permitted provided that the following conditions 7103785Sjeff * are met: 8103785Sjeff * 1. Redistributions of source code must retain the above copyright 9103785Sjeff * notice unmodified, this list of conditions, and the following 10103785Sjeff * disclaimer. 11103785Sjeff * 2. Redistributions in binary form must reproduce the above copyright 12103785Sjeff * notice, this list of conditions and the following disclaimer in the 13103785Sjeff * documentation and/or other materials provided with the distribution. 14103785Sjeff * 15103785Sjeff * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16103785Sjeff * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17103785Sjeff * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18103785Sjeff * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19103785Sjeff * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20103785Sjeff * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21103785Sjeff * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22103785Sjeff * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23103785Sjeff * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24103785Sjeff * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25103785Sjeff */ 26103785Sjeff 27116182Sobrien#include <sys/cdefs.h> 28116182Sobrien__FBSDID("$FreeBSD: head/sys/kern/kern_alq.c 116182 2003-06-11 00:56:59Z obrien $"); 29116182Sobrien 30103785Sjeff#include <sys/param.h> 31103785Sjeff#include <sys/systm.h> 32103785Sjeff#include <sys/kernel.h> 33103785Sjeff#include <sys/kthread.h> 34103785Sjeff#include <sys/lock.h> 35103785Sjeff#include <sys/mutex.h> 36103785Sjeff#include <sys/namei.h> 37103785Sjeff#include <sys/proc.h> 38103785Sjeff#include <sys/vnode.h> 39103785Sjeff#include <sys/alq.h> 40103785Sjeff#include <sys/malloc.h> 41103785Sjeff#include <sys/unistd.h> 42103785Sjeff#include <sys/fcntl.h> 43103785Sjeff#include <sys/eventhandler.h> 44103785Sjeff 45103785Sjeff/* Async. Logging Queue */ 46103785Sjeffstruct alq { 47103785Sjeff int aq_entmax; /* Max entries */ 48103785Sjeff int aq_entlen; /* Entry length */ 49103785Sjeff char *aq_entbuf; /* Buffer for stored entries */ 50103785Sjeff int aq_flags; /* Queue flags */ 51103785Sjeff struct mtx aq_mtx; /* Queue lock */ 52103785Sjeff struct vnode *aq_vp; /* Open vnode handle */ 53103830Sjeff struct ucred *aq_cred; /* Credentials of the opening thread */ 54103785Sjeff struct ale *aq_first; /* First ent */ 55103785Sjeff struct ale *aq_entfree; /* First free ent */ 56103785Sjeff struct ale *aq_entvalid; /* First ent valid for writing */ 57103785Sjeff LIST_ENTRY(alq) aq_act; /* List of active queues */ 58103785Sjeff LIST_ENTRY(alq) aq_link; /* List of all queues */ 59103785Sjeff}; 60103785Sjeff 61103785Sjeff#define AQ_WANTED 0x0001 /* Wakeup sleeper when io is done */ 62103785Sjeff#define AQ_ACTIVE 0x0002 /* on the active list */ 63103785Sjeff#define AQ_FLUSHING 0x0004 /* doing IO */ 64103785Sjeff#define AQ_SHUTDOWN 0x0008 /* Queue no longer valid */ 65103785Sjeff 66103785Sjeff#define ALQ_LOCK(alq) mtx_lock_spin(&(alq)->aq_mtx) 67103785Sjeff#define ALQ_UNLOCK(alq) mtx_unlock_spin(&(alq)->aq_mtx) 68103785Sjeff 69103785Sjeffstatic MALLOC_DEFINE(M_ALD, "ALD", "ALD"); 70103785Sjeff 71103785Sjeff/* 72103785Sjeff * The ald_mtx protects the ald_queues list and the ald_active list. 73103785Sjeff */ 74103785Sjeffstatic struct mtx ald_mtx; 75103785Sjeffstatic LIST_HEAD(, alq) ald_queues; 76103785Sjeffstatic LIST_HEAD(, alq) ald_active; 77103785Sjeffstatic int ald_shutingdown = 0; 78103995Sjeffstruct thread *ald_thread; 79103995Sjeffstatic struct proc *ald_proc; 80103785Sjeff 81103785Sjeff#define ALD_LOCK() mtx_lock(&ald_mtx) 82103785Sjeff#define ALD_UNLOCK() mtx_unlock(&ald_mtx) 83103785Sjeff 84103785Sjeff/* Daemon functions */ 85103785Sjeffstatic int ald_add(struct alq *); 86103785Sjeffstatic int ald_rem(struct alq *); 87103785Sjeffstatic void ald_startup(void *); 88103785Sjeffstatic void ald_daemon(void); 89103785Sjeffstatic void ald_shutdown(void *, int); 90103785Sjeffstatic void ald_activate(struct alq *); 91103785Sjeffstatic void ald_deactivate(struct alq *); 92103785Sjeff 93103785Sjeff/* Internal queue functions */ 94103785Sjeffstatic void alq_shutdown(struct alq *); 95103785Sjeffstatic int alq_doio(struct alq *); 96103785Sjeff 97103785Sjeff 98103785Sjeff/* 99103785Sjeff * Add a new queue to the global list. Fail if we're shutting down. 100103785Sjeff */ 101103785Sjeffstatic int 102103785Sjeffald_add(struct alq *alq) 103103785Sjeff{ 104103785Sjeff int error; 105103785Sjeff 106103785Sjeff error = 0; 107103785Sjeff 108103785Sjeff ALD_LOCK(); 109103785Sjeff if (ald_shutingdown) { 110103785Sjeff error = EBUSY; 111103785Sjeff goto done; 112103785Sjeff } 113103785Sjeff LIST_INSERT_HEAD(&ald_queues, alq, aq_link); 114103785Sjeffdone: 115103785Sjeff ALD_UNLOCK(); 116103785Sjeff return (error); 117103785Sjeff} 118103785Sjeff 119103785Sjeff/* 120103785Sjeff * Remove a queue from the global list unless we're shutting down. If so, 121103785Sjeff * the ald will take care of cleaning up it's resources. 122103785Sjeff */ 123103785Sjeffstatic int 124103785Sjeffald_rem(struct alq *alq) 125103785Sjeff{ 126103785Sjeff int error; 127103785Sjeff 128103785Sjeff error = 0; 129103785Sjeff 130103785Sjeff ALD_LOCK(); 131103785Sjeff if (ald_shutingdown) { 132103785Sjeff error = EBUSY; 133103785Sjeff goto done; 134103785Sjeff } 135103785Sjeff LIST_REMOVE(alq, aq_link); 136103785Sjeffdone: 137103785Sjeff ALD_UNLOCK(); 138103785Sjeff return (error); 139103785Sjeff} 140103785Sjeff 141103785Sjeff/* 142103785Sjeff * Put a queue on the active list. This will schedule it for writing. 143103785Sjeff */ 144103785Sjeffstatic void 145103785Sjeffald_activate(struct alq *alq) 146103785Sjeff{ 147103785Sjeff LIST_INSERT_HEAD(&ald_active, alq, aq_act); 148103785Sjeff wakeup(&ald_active); 149103785Sjeff} 150103785Sjeff 151103785Sjeffstatic void 152103785Sjeffald_deactivate(struct alq *alq) 153103785Sjeff{ 154103785Sjeff LIST_REMOVE(alq, aq_act); 155103785Sjeff alq->aq_flags &= ~AQ_ACTIVE; 156103785Sjeff} 157103785Sjeff 158103785Sjeffstatic void 159103785Sjeffald_startup(void *unused) 160103785Sjeff{ 161103785Sjeff mtx_init(&ald_mtx, "ALDmtx", NULL, MTX_DEF|MTX_QUIET); 162103785Sjeff LIST_INIT(&ald_queues); 163103785Sjeff LIST_INIT(&ald_active); 164103785Sjeff} 165103785Sjeff 166103785Sjeffstatic void 167103785Sjeffald_daemon(void) 168103785Sjeff{ 169103785Sjeff int needwakeup; 170103785Sjeff struct alq *alq; 171103785Sjeff 172103785Sjeff mtx_lock(&Giant); 173103785Sjeff 174103995Sjeff ald_thread = FIRST_THREAD_IN_PROC(ald_proc); 175103995Sjeff 176103785Sjeff EVENTHANDLER_REGISTER(shutdown_pre_sync, ald_shutdown, NULL, 177103785Sjeff SHUTDOWN_PRI_FIRST); 178103785Sjeff 179103785Sjeff ALD_LOCK(); 180103785Sjeff 181103785Sjeff for (;;) { 182103785Sjeff while ((alq = LIST_FIRST(&ald_active)) == NULL) 183103785Sjeff msleep(&ald_active, &ald_mtx, PWAIT, "aldslp", 0); 184103785Sjeff 185103785Sjeff ALQ_LOCK(alq); 186103785Sjeff ald_deactivate(alq); 187103785Sjeff ALD_UNLOCK(); 188103785Sjeff needwakeup = alq_doio(alq); 189103785Sjeff ALQ_UNLOCK(alq); 190103785Sjeff if (needwakeup) 191103785Sjeff wakeup(alq); 192103785Sjeff ALD_LOCK(); 193103785Sjeff } 194103785Sjeff} 195103785Sjeff 196103785Sjeffstatic void 197103785Sjeffald_shutdown(void *arg, int howto) 198103785Sjeff{ 199103785Sjeff struct alq *alq; 200103785Sjeff 201103785Sjeff ALD_LOCK(); 202103785Sjeff ald_shutingdown = 1; 203103785Sjeff 204103785Sjeff while ((alq = LIST_FIRST(&ald_queues)) != NULL) { 205103785Sjeff LIST_REMOVE(alq, aq_link); 206103785Sjeff ALD_UNLOCK(); 207103785Sjeff alq_shutdown(alq); 208103785Sjeff ALD_LOCK(); 209103785Sjeff } 210103785Sjeff ALD_UNLOCK(); 211103785Sjeff} 212103785Sjeff 213103785Sjeffstatic void 214103785Sjeffalq_shutdown(struct alq *alq) 215103785Sjeff{ 216103785Sjeff ALQ_LOCK(alq); 217103785Sjeff 218103785Sjeff /* Stop any new writers. */ 219103785Sjeff alq->aq_flags |= AQ_SHUTDOWN; 220103785Sjeff 221103785Sjeff /* Drain IO */ 222103785Sjeff while (alq->aq_flags & (AQ_FLUSHING|AQ_ACTIVE)) { 223103785Sjeff alq->aq_flags |= AQ_WANTED; 224103785Sjeff ALQ_UNLOCK(alq); 225103785Sjeff tsleep(alq, PWAIT, "aldclose", 0); 226103785Sjeff ALQ_LOCK(alq); 227103785Sjeff } 228103785Sjeff ALQ_UNLOCK(alq); 229103785Sjeff 230103995Sjeff vn_close(alq->aq_vp, FWRITE, alq->aq_cred, 231103830Sjeff curthread); 232103830Sjeff crfree(alq->aq_cred); 233103785Sjeff} 234103785Sjeff 235103785Sjeff/* 236103785Sjeff * Flush all pending data to disk. This operation will block. 237103785Sjeff */ 238103785Sjeffstatic int 239103785Sjeffalq_doio(struct alq *alq) 240103785Sjeff{ 241103785Sjeff struct thread *td; 242103785Sjeff struct mount *mp; 243103785Sjeff struct vnode *vp; 244103785Sjeff struct uio auio; 245103785Sjeff struct iovec aiov[2]; 246103785Sjeff struct ale *ale; 247103785Sjeff struct ale *alstart; 248103785Sjeff int totlen; 249103785Sjeff int iov; 250103785Sjeff 251103785Sjeff vp = alq->aq_vp; 252103785Sjeff td = curthread; 253103785Sjeff totlen = 0; 254103785Sjeff iov = 0; 255103785Sjeff 256103785Sjeff alstart = ale = alq->aq_entvalid; 257103785Sjeff alq->aq_entvalid = NULL; 258103785Sjeff 259103785Sjeff bzero(&aiov, sizeof(aiov)); 260103785Sjeff bzero(&auio, sizeof(auio)); 261103785Sjeff 262103785Sjeff do { 263103785Sjeff if (aiov[iov].iov_base == NULL) 264103785Sjeff aiov[iov].iov_base = ale->ae_data; 265103785Sjeff aiov[iov].iov_len += alq->aq_entlen; 266103785Sjeff totlen += alq->aq_entlen; 267103785Sjeff /* Check to see if we're wrapping the buffer */ 268103785Sjeff if (ale->ae_data + alq->aq_entlen != ale->ae_next->ae_data) 269103785Sjeff iov++; 270103785Sjeff ale->ae_flags &= ~AE_VALID; 271103785Sjeff ale = ale->ae_next; 272103785Sjeff } while (ale->ae_flags & AE_VALID); 273103785Sjeff 274103785Sjeff alq->aq_flags |= AQ_FLUSHING; 275103785Sjeff ALQ_UNLOCK(alq); 276103785Sjeff 277103785Sjeff if (iov == 2 || aiov[iov].iov_base == NULL) 278103785Sjeff iov--; 279103785Sjeff 280103785Sjeff auio.uio_iov = &aiov[0]; 281103785Sjeff auio.uio_offset = 0; 282103785Sjeff auio.uio_segflg = UIO_SYSSPACE; 283103785Sjeff auio.uio_rw = UIO_WRITE; 284103785Sjeff auio.uio_iovcnt = iov + 1; 285103785Sjeff auio.uio_resid = totlen; 286103785Sjeff auio.uio_td = td; 287103785Sjeff 288103785Sjeff /* 289103785Sjeff * Do all of the junk required to write now. 290103785Sjeff */ 291103785Sjeff vn_start_write(vp, &mp, V_WAIT); 292103785Sjeff vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 293103830Sjeff VOP_LEASE(vp, td, alq->aq_cred, LEASE_WRITE); 294103785Sjeff /* XXX error ignored */ 295103830Sjeff VOP_WRITE(vp, &auio, IO_UNIT | IO_APPEND, alq->aq_cred); 296103785Sjeff VOP_UNLOCK(vp, 0, td); 297103785Sjeff vn_finished_write(mp); 298103785Sjeff 299103785Sjeff ALQ_LOCK(alq); 300103785Sjeff alq->aq_flags &= ~AQ_FLUSHING; 301103785Sjeff 302103785Sjeff if (alq->aq_entfree == NULL) 303103785Sjeff alq->aq_entfree = alstart; 304103785Sjeff 305103785Sjeff if (alq->aq_flags & AQ_WANTED) { 306103785Sjeff alq->aq_flags &= ~AQ_WANTED; 307103785Sjeff return (1); 308103785Sjeff } 309103785Sjeff 310103785Sjeff return(0); 311103785Sjeff} 312103785Sjeff 313103785Sjeffstatic struct kproc_desc ald_kp = { 314103785Sjeff "ALQ Daemon", 315103785Sjeff ald_daemon, 316103995Sjeff &ald_proc 317103785Sjeff}; 318103785Sjeff 319103785SjeffSYSINIT(aldthread, SI_SUB_KTHREAD_IDLE, SI_ORDER_ANY, kproc_start, &ald_kp) 320103785SjeffSYSINIT(ald, SI_SUB_LOCK, SI_ORDER_ANY, ald_startup, NULL) 321103785Sjeff 322103785Sjeff 323103785Sjeff/* User visible queue functions */ 324103785Sjeff 325103785Sjeff/* 326103785Sjeff * Create the queue data structure, allocate the buffer, and open the file. 327103785Sjeff */ 328103785Sjeffint 329103785Sjeffalq_open(struct alq **alqp, const char *file, int size, int count) 330103785Sjeff{ 331103785Sjeff struct thread *td; 332103785Sjeff struct nameidata nd; 333103785Sjeff struct ale *ale; 334103785Sjeff struct ale *alp; 335103785Sjeff struct alq *alq; 336103785Sjeff char *bufp; 337103785Sjeff int flags; 338103785Sjeff int error; 339103785Sjeff int i; 340103785Sjeff 341103785Sjeff *alqp = NULL; 342103785Sjeff td = curthread; 343103785Sjeff 344103785Sjeff NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, file, td); 345103995Sjeff flags = FWRITE | O_NOFOLLOW | O_CREAT; 346103785Sjeff 347103785Sjeff error = vn_open(&nd, &flags, 0); 348103785Sjeff if (error) 349103785Sjeff return (error); 350103785Sjeff 351103785Sjeff NDFREE(&nd, NDF_ONLY_PNBUF); 352103785Sjeff /* We just unlock so we hold a reference */ 353103785Sjeff VOP_UNLOCK(nd.ni_vp, 0, td); 354103785Sjeff 355111119Simp alq = malloc(sizeof(*alq), M_ALD, M_WAITOK|M_ZERO); 356111119Simp alq->aq_entbuf = malloc(count * size, M_ALD, M_WAITOK|M_ZERO); 357111119Simp alq->aq_first = malloc(sizeof(*ale) * count, M_ALD, M_WAITOK|M_ZERO); 358103785Sjeff alq->aq_vp = nd.ni_vp; 359103830Sjeff alq->aq_cred = crhold(td->td_ucred); 360103785Sjeff alq->aq_entmax = count; 361103785Sjeff alq->aq_entlen = size; 362103785Sjeff alq->aq_entfree = alq->aq_first; 363103785Sjeff 364103785Sjeff mtx_init(&alq->aq_mtx, "ALD Queue", NULL, MTX_SPIN|MTX_QUIET); 365103785Sjeff 366103785Sjeff bufp = alq->aq_entbuf; 367103785Sjeff ale = alq->aq_first; 368103785Sjeff alp = NULL; 369103785Sjeff 370103785Sjeff /* Match up entries with buffers */ 371103785Sjeff for (i = 0; i < count; i++) { 372103785Sjeff if (alp) 373103785Sjeff alp->ae_next = ale; 374103785Sjeff ale->ae_data = bufp; 375103785Sjeff alp = ale; 376103785Sjeff ale++; 377103785Sjeff bufp += size; 378103785Sjeff } 379103785Sjeff 380103785Sjeff alp->ae_next = alq->aq_first; 381103785Sjeff 382103785Sjeff if ((error = ald_add(alq)) != 0) 383103785Sjeff return (error); 384103785Sjeff *alqp = alq; 385103785Sjeff 386103785Sjeff return (0); 387103785Sjeff} 388103785Sjeff 389103785Sjeff/* 390103785Sjeff * Copy a new entry into the queue. If the operation would block either 391103785Sjeff * wait or return an error depending on the value of waitok. 392103785Sjeff */ 393103785Sjeffint 394103785Sjeffalq_write(struct alq *alq, void *data, int waitok) 395103785Sjeff{ 396103785Sjeff struct ale *ale; 397103785Sjeff 398103785Sjeff if ((ale = alq_get(alq, waitok)) == NULL) 399103785Sjeff return (EWOULDBLOCK); 400103785Sjeff 401103785Sjeff bcopy(data, ale->ae_data, alq->aq_entlen); 402103785Sjeff alq_post(alq, ale); 403103785Sjeff 404103785Sjeff return (0); 405103785Sjeff} 406103785Sjeff 407103785Sjeffstruct ale * 408103785Sjeffalq_get(struct alq *alq, int waitok) 409103785Sjeff{ 410103785Sjeff struct ale *ale; 411103785Sjeff struct ale *aln; 412103785Sjeff 413103785Sjeff ale = NULL; 414103785Sjeff 415103785Sjeff ALQ_LOCK(alq); 416103785Sjeff 417103785Sjeff /* Loop until we get an entry or we're shutting down */ 418103785Sjeff while ((alq->aq_flags & AQ_SHUTDOWN) == 0 && 419103785Sjeff (ale = alq->aq_entfree) == NULL && 420103785Sjeff (waitok & ALQ_WAITOK)) { 421103785Sjeff alq->aq_flags |= AQ_WANTED; 422103785Sjeff ALQ_UNLOCK(alq); 423103785Sjeff tsleep(alq, PWAIT, "alqget", 0); 424103785Sjeff ALQ_LOCK(alq); 425103785Sjeff } 426103785Sjeff 427103785Sjeff if (ale != NULL) { 428103785Sjeff aln = ale->ae_next; 429103785Sjeff if ((aln->ae_flags & AE_VALID) == 0) 430103785Sjeff alq->aq_entfree = aln; 431115308Sjeff else 432115308Sjeff alq->aq_entfree = NULL; 433103785Sjeff } else 434103785Sjeff ALQ_UNLOCK(alq); 435103785Sjeff 436103785Sjeff 437103785Sjeff return (ale); 438103785Sjeff} 439103785Sjeff 440103785Sjeffvoid 441103785Sjeffalq_post(struct alq *alq, struct ale *ale) 442103785Sjeff{ 443103785Sjeff int activate; 444103785Sjeff 445103785Sjeff ale->ae_flags |= AE_VALID; 446103785Sjeff 447103785Sjeff if (alq->aq_entvalid == NULL) 448103785Sjeff alq->aq_entvalid = ale; 449103785Sjeff 450103785Sjeff if ((alq->aq_flags & AQ_ACTIVE) == 0) { 451103785Sjeff alq->aq_flags |= AQ_ACTIVE; 452103785Sjeff activate = 1; 453103785Sjeff } else 454103785Sjeff activate = 0; 455103785Sjeff 456103785Sjeff ALQ_UNLOCK(alq); 457103785Sjeff if (activate) { 458103785Sjeff ALD_LOCK(); 459103785Sjeff ald_activate(alq); 460103785Sjeff ALD_UNLOCK(); 461103785Sjeff } 462103785Sjeff} 463103785Sjeff 464103785Sjeffvoid 465103785Sjeffalq_flush(struct alq *alq) 466103785Sjeff{ 467103785Sjeff int needwakeup = 0; 468103785Sjeff 469103785Sjeff ALD_LOCK(); 470103785Sjeff ALQ_LOCK(alq); 471103785Sjeff if (alq->aq_flags & AQ_ACTIVE) { 472103785Sjeff ald_deactivate(alq); 473103785Sjeff ALD_UNLOCK(); 474103785Sjeff needwakeup = alq_doio(alq); 475103785Sjeff } else 476103785Sjeff ALD_UNLOCK(); 477103785Sjeff ALQ_UNLOCK(alq); 478103785Sjeff 479103785Sjeff if (needwakeup) 480103785Sjeff wakeup(alq); 481103785Sjeff} 482103785Sjeff 483103785Sjeff/* 484103785Sjeff * Flush remaining data, close the file and free all resources. 485103785Sjeff */ 486103785Sjeffvoid 487103785Sjeffalq_close(struct alq *alq) 488103785Sjeff{ 489103785Sjeff /* 490103785Sjeff * If we're already shuting down someone else will flush and close 491103785Sjeff * the vnode. 492103785Sjeff */ 493103785Sjeff if (ald_rem(alq) != 0) 494103785Sjeff return; 495103785Sjeff 496103785Sjeff /* 497103785Sjeff * Drain all pending IO. 498103785Sjeff */ 499103785Sjeff alq_shutdown(alq); 500103785Sjeff 501103785Sjeff mtx_destroy(&alq->aq_mtx); 502103785Sjeff free(alq->aq_first, M_ALD); 503103785Sjeff free(alq->aq_entbuf, M_ALD); 504103785Sjeff free(alq, M_ALD); 505103785Sjeff} 506