2 * Copyright 2000, International Business Machines Corporation and others.
5 * This software has been released under the terms of the IBM Public
6 * License. For details, see the LICENSE file in the top-level source
7 * directory or online at http://www.openafs.org/dl/license10.html
13 #include <afsconfig.h>
14 #include "afs/param.h"
20 #include "afs/sysincludes.h" /* Standard vendor system headers */
21 #include "afsincludes.h" /* Afs-based standard headers */
22 #include "afs/afs_stats.h" /* afs statistics */
23 #include "afs/afs_osi.h"
24 #include "afs/afs_md5.h"
26 /* Local variables. */
27 afs_rwlock_t afs_xcell; /* Export for cmdebug peeking at locks */
30 * AFSDB implementation:
32 * afs_StopAFSDB: terminate the AFSDB handler, used on shutdown
33 * afs_AFSDBHandler: entry point for user-space AFSDB request handler
34 * afs_GetCellHostsAFSDB: query the AFSDB handler and wait for response
35 * afs_LookupAFSDB: look up AFSDB for given cell name and create locally
39 afs_rwlock_t afsdb_client_lock; /* Serializes client requests */
40 afs_rwlock_t afsdb_req_lock; /* Serializes client requests */
41 static char afsdb_handler_running; /* Protected by GLOCK */
42 static char afsdb_handler_shutdown; /* Protected by GLOCK */
44 /* from cellconfig.h */
45 #define MAXCELLCHARS 64
47 /* lock moved to afsdb_req_lock for cmdebug */
56 if (afsdb_handler_running) {
57 afs_osi_Wakeup(&afsdb_req);
59 afsdb_handler_shutdown = 1;
60 afs_termState = AFSOP_STOP_RXEVENT;
65 afs_AFSDBHandler(char *acellName, int acellNameLen, afs_int32 * kernelMsg)
67 afs_int32 timeout, code;
68 afs_int32 cellHosts[MAXCELLHOSTS];
70 if (afsdb_handler_shutdown)
72 afsdb_handler_running = 1;
74 ObtainSharedLock(&afsdb_req_lock, 683);
75 if (afsdb_req.pending) {
78 UpgradeSToWLock(&afsdb_req_lock, 684);
79 hostCount = kernelMsg[0];
80 timeout = kernelMsg[1];
82 timeout += osi_Time();
84 for (i = 0; i < MAXCELLHOSTS; i++) {
88 cellHosts[i] = kernelMsg[2 + i];
92 code = afs_NewCell(acellName, cellHosts, CNoSUID, NULL, 0, 0,
95 if (!hostCount || (code && code != EEXIST))
96 /* null out the cellname if the lookup failed */
97 afsdb_req.cellname = NULL;
99 /* If we found an alias, create it */
100 if (afs_strcasecmp(afsdb_req.cellname, acellName))
101 afs_NewCellAlias(afsdb_req.cellname, acellName);
103 /* Request completed, wake up the relevant thread */
104 afsdb_req.pending = 0;
105 afsdb_req.complete = 1;
106 afs_osi_Wakeup(&afsdb_req);
107 ConvertWToSLock(&afsdb_req_lock);
109 ConvertSToRLock(&afsdb_req_lock);
111 /* Wait for a request */
112 while (afsdb_req.pending == 0 && afs_termState != AFSOP_STOP_AFSDB) {
113 ReleaseReadLock(&afsdb_req_lock);
114 afs_osi_Sleep(&afsdb_req);
115 ObtainReadLock(&afsdb_req_lock);
118 /* Check if we're shutting down */
119 if (afs_termState == AFSOP_STOP_AFSDB) {
120 ReleaseReadLock(&afsdb_req_lock);
122 /* Inform anyone waiting for us that we're going away */
123 afsdb_handler_shutdown = 1;
124 afsdb_handler_running = 0;
125 afs_osi_Wakeup(&afsdb_req);
127 afs_termState = AFSOP_STOP_RXEVENT;
128 afs_osi_Wakeup(&afs_termState);
132 /* Return the lookup request to userspace */
133 strncpy(acellName, afsdb_req.cellname, acellNameLen);
134 ReleaseReadLock(&afsdb_req_lock);
139 afs_GetCellHostsAFSDB(char *acellName)
142 if (!afsdb_handler_running)
145 ObtainWriteLock(&afsdb_client_lock, 685);
146 ObtainWriteLock(&afsdb_req_lock, 686);
148 afsdb_req.cellname = acellName;
150 afsdb_req.complete = 0;
151 afsdb_req.pending = 1;
152 afs_osi_Wakeup(&afsdb_req);
153 ConvertWToRLock(&afsdb_req_lock);
155 while (afsdb_handler_running && !afsdb_req.complete) {
156 ReleaseReadLock(&afsdb_req_lock);
157 afs_osi_Sleep(&afsdb_req);
158 ObtainReadLock(&afsdb_req_lock);
161 ReleaseReadLock(&afsdb_req_lock);
162 ReleaseWriteLock(&afsdb_client_lock);
164 if (afsdb_req.cellname) {
172 afs_LookupAFSDB(char *acellName)
176 char *cellName = afs_strdup(acellName);
178 code = afs_GetCellHostsAFSDB(cellName);
179 afs_Trace2(afs_iclSetp, CM_TRACE_AFSDB, ICL_TYPE_STRING, cellName,
180 ICL_TYPE_INT32, code);
181 afs_osi_FreeStr(cellName);
186 * Cell name-to-ID mapping
188 * afs_cellname_new: create a new cell name, optional cell number
189 * afs_cellname_lookup_id: look up a cell name
190 * afs_cellname_lookup_name: look up a cell number
191 * afs_cellname_ref: note that this cell name was referenced somewhere
192 * afs_cellname_init: load the list of cells from given inode
193 * afs_cellname_write: write in-kernel list of cells to disk
196 struct cell_name *afs_cellname_head; /* Export for kdump */
197 static ino_t afs_cellname_inode;
198 static int afs_cellname_inode_set;
199 static int afs_cellname_dirty;
200 static afs_int32 afs_cellnum_next;
202 static struct cell_name *
203 afs_cellname_new(char *name, afs_int32 cellnum)
205 struct cell_name *cn;
208 cellnum = afs_cellnum_next;
210 cn = (struct cell_name *)afs_osi_Alloc(sizeof(*cn));
211 cn->next = afs_cellname_head;
212 cn->cellnum = cellnum;
213 cn->cellname = afs_strdup(name);
215 afs_cellname_head = cn;
217 if (cellnum >= afs_cellnum_next)
218 afs_cellnum_next = cellnum + 1;
223 static struct cell_name *
224 afs_cellname_lookup_id(afs_int32 cellnum)
226 struct cell_name *cn;
228 for (cn = afs_cellname_head; cn; cn = cn->next)
229 if (cn->cellnum == cellnum)
235 static struct cell_name *
236 afs_cellname_lookup_name(char *name)
238 struct cell_name *cn;
240 for (cn = afs_cellname_head; cn; cn = cn->next)
241 if (strcmp(cn->cellname, name) == 0)
248 afs_cellname_ref(struct cell_name *cn)
252 afs_cellname_dirty = 1;
257 afs_cellname_init(ino_t inode, int lookupcode)
259 struct osi_file *tfile;
262 ObtainWriteLock(&afs_xcell, 692);
264 afs_cellnum_next = 1;
265 afs_cellname_dirty = 0;
267 if (cacheDiskType == AFS_FCACHE_TYPE_MEM) {
268 ReleaseWriteLock(&afs_xcell);
272 ReleaseWriteLock(&afs_xcell);
276 tfile = osi_UFSOpen(inode);
278 ReleaseWriteLock(&afs_xcell);
282 afs_cellname_inode = inode;
283 afs_cellname_inode_set = 1;
286 afs_int32 cellnum, clen, magic;
287 struct cell_name *cn;
290 cc = afs_osi_Read(tfile, off, &magic, sizeof(magic));
291 if (cc != sizeof(magic))
293 if (magic != AFS_CELLINFO_MAGIC)
297 cc = afs_osi_Read(tfile, off, &cellnum, sizeof(cellnum));
298 if (cc != sizeof(cellnum))
302 cc = afs_osi_Read(tfile, off, &clen, sizeof(clen));
303 if (cc != sizeof(clen))
307 cellname = afs_osi_Alloc(clen + 1);
311 cc = afs_osi_Read(tfile, off, cellname, clen);
313 afs_osi_Free(cellname, clen + 1);
317 cellname[clen] = '\0';
319 if (afs_cellname_lookup_name(cellname)
320 || afs_cellname_lookup_id(cellnum)) {
321 afs_osi_Free(cellname, clen + 1);
325 cn = afs_cellname_new(cellname, cellnum);
326 afs_osi_Free(cellname, clen + 1);
330 ReleaseWriteLock(&afs_xcell);
335 afs_cellname_write(void)
337 struct osi_file *tfile;
338 struct cell_name *cn;
341 if (!afs_cellname_dirty || !afs_cellname_inode_set)
343 if (afs_initState != 300)
346 ObtainWriteLock(&afs_xcell, 693);
347 afs_cellname_dirty = 0;
349 tfile = osi_UFSOpen(afs_cellname_inode);
351 ReleaseWriteLock(&afs_xcell);
355 for (cn = afs_cellname_head; cn; cn = cn->next) {
356 afs_int32 magic, cellnum, clen;
362 magic = AFS_CELLINFO_MAGIC;
363 cc = afs_osi_Write(tfile, off, &magic, sizeof(magic));
364 if (cc != sizeof(magic))
368 cellnum = cn->cellnum;
369 cc = afs_osi_Write(tfile, off, &cellnum, sizeof(cellnum));
370 if (cc != sizeof(cellnum))
374 clen = strlen(cn->cellname);
375 cc = afs_osi_Write(tfile, off, &clen, sizeof(clen));
376 if (cc != sizeof(clen))
380 cc = afs_osi_Write(tfile, off, cn->cellname, clen);
387 ReleaseWriteLock(&afs_xcell);
392 * Cell alias implementation
394 * afs_FindCellAlias: look up cell alias by alias name
395 * afs_GetCellAlias: get cell alias by index (starting at 0)
396 * afs_PutCellAlias: put back a cell alias returned by Find or Get
397 * afs_NewCellAlias: create new cell alias entry
400 struct cell_alias *afs_cellalias_head; /* Export for kdump */
401 static afs_int32 afs_cellalias_index;
402 static int afs_CellOrAliasExists_nl(char *aname); /* Forward declaration */
404 static struct cell_alias *
405 afs_FindCellAlias(char *alias)
407 struct cell_alias *tc;
409 for (tc = afs_cellalias_head; tc != NULL; tc = tc->next)
410 if (!strcmp(alias, tc->alias))
416 afs_GetCellAlias(int index)
418 struct cell_alias *tc;
420 ObtainReadLock(&afs_xcell);
421 for (tc = afs_cellalias_head; tc != NULL; tc = tc->next)
422 if (tc->index == index)
424 ReleaseReadLock(&afs_xcell);
430 afs_PutCellAlias(struct cell_alias *a)
436 afs_NewCellAlias(char *alias, char *cell)
438 struct cell_alias *tc;
440 ObtainSharedLock(&afs_xcell, 681);
441 if (afs_CellOrAliasExists_nl(alias)) {
442 ReleaseSharedLock(&afs_xcell);
446 UpgradeSToWLock(&afs_xcell, 682);
447 tc = (struct cell_alias *)afs_osi_Alloc(sizeof(struct cell_alias));
448 tc->alias = afs_strdup(alias);
449 tc->cell = afs_strdup(cell);
450 tc->next = afs_cellalias_head;
451 tc->index = afs_cellalias_index++;
452 afs_cellalias_head = tc;
453 ReleaseWriteLock(&afs_xcell);
455 afs_DynrootInvalidate();
460 * Actual cell list implementation
462 * afs_UpdateCellLRU: bump given cell up to the front of the LRU queue
463 * afs_RefreshCell: look up cell information in AFSDB if timeout expired
465 * afs_TraverseCells: execute a callback for each existing cell
466 * afs_TraverseCells_nl: same as above except without locking afs_xcell
467 * afs_choose_cell_by_{name,num,index}: useful traversal callbacks
469 * afs_FindCellByName: return a cell with a given name, if it exists
470 * afs_FindCellByName_nl: same as above, without locking afs_xcell
471 * afs_GetCellByName: same as FindCellByName but tries AFSDB if not found
472 * afs_GetCell: return a cell with a given cell number
473 * afs_GetCellStale: same as GetCell, but does not try to refresh the data
474 * afs_GetCellByIndex: return a cell with a given index number (starting at 0)
476 * afs_GetPrimaryCell: return the primary cell, if any
477 * afs_IsPrimaryCell: returns true iff the given cell is the primary cell
478 * afs_IsPrimaryCellNum: returns afs_IsPrimaryCell(afs_GetCell(cellnum))
479 * afs_SetPrimaryCell: set the primary cell name to the given cell name
481 * afs_NewCell: create or update a cell entry
484 struct afs_q CellLRU; /* Export for kdump */
485 static char *afs_thiscell;
486 afs_int32 afs_cellindex; /* Export for kdump */
489 afs_UpdateCellLRU(struct cell *c)
491 ObtainWriteLock(&afs_xcell, 100);
493 QAdd(&CellLRU, &c->lruq);
494 ReleaseWriteLock(&afs_xcell);
498 afs_RefreshCell(struct cell *ac)
500 if (ac->states & CNoAFSDB)
502 if (!ac->cellHosts[0] || (ac->timeout && ac->timeout <= osi_Time()))
503 afs_LookupAFSDB(ac->cellName);
507 afs_TraverseCells_nl(void *(*cb) (struct cell *, void *), void *arg)
509 struct afs_q *cq, *tq;
513 for (cq = CellLRU.next; cq != &CellLRU; cq = tq) {
516 /* This is assuming that a NULL return is acceptable. */
532 afs_TraverseCells(void *(*cb) (struct cell *, void *), void *arg)
536 ObtainReadLock(&afs_xcell);
537 ret = afs_TraverseCells_nl(cb, arg);
538 ReleaseReadLock(&afs_xcell);
544 afs_choose_cell_by_name(struct cell *cell, void *arg)
550 return strcmp(cell->cellName, (char *)arg) ? NULL : cell;
555 afs_choose_cell_by_handle(struct cell *cell, void *arg)
561 return memcmp(cell->cellHandle, (char *)arg, 16) ? NULL : cell;
566 afs_choose_cell_by_num(struct cell *cell, void *arg)
568 return (cell->cellNum == *((afs_int32 *) arg)) ? cell : NULL;
572 afs_choose_cell_by_index(struct cell *cell, void *arg)
574 return (cell->cellIndex == *((afs_int32 *) arg)) ? cell : NULL;
578 afs_FindCellByName_nl(char *acellName, afs_int32 locktype)
580 return afs_TraverseCells_nl(&afs_choose_cell_by_name, acellName);
584 afs_FindCellByName(char *acellName, afs_int32 locktype)
586 return afs_TraverseCells(&afs_choose_cell_by_name, acellName);
590 afs_GetCellByName(char *acellName, afs_int32 locktype)
594 tc = afs_FindCellByName(acellName, locktype);
596 afs_LookupAFSDB(acellName);
597 tc = afs_FindCellByName(acellName, locktype);
600 afs_cellname_ref(tc->cnamep);
601 afs_UpdateCellLRU(tc);
609 afs_GetCell(afs_int32 cellnum, afs_int32 locktype)
612 struct cell_name *cn;
614 tc = afs_GetCellStale(cellnum, locktype);
618 ObtainReadLock(&afs_xcell);
619 cn = afs_cellname_lookup_id(cellnum);
620 ReleaseReadLock(&afs_xcell);
622 tc = afs_GetCellByName(cn->cellname, locktype);
628 afs_GetCellStale(afs_int32 cellnum, afs_int32 locktype)
632 tc = afs_TraverseCells(&afs_choose_cell_by_num, &cellnum);
634 afs_cellname_ref(tc->cnamep);
635 afs_UpdateCellLRU(tc);
641 afs_GetCellByIndex(afs_int32 index, afs_int32 locktype)
645 tc = afs_TraverseCells(&afs_choose_cell_by_index, &index);
647 afs_UpdateCellLRU(tc);
652 afs_GetCellByHandle(void *handle, afs_int32 locktype)
656 tc = afs_TraverseCells(&afs_choose_cell_by_handle, handle);
658 afs_UpdateCellLRU(tc);
663 afs_GetPrimaryCell(afs_int32 locktype)
665 return afs_GetCellByName(afs_thiscell, locktype);
669 afs_IsPrimaryCell(struct cell *cell)
671 /* Simple safe checking */
674 } else if (!afs_thiscell) {
675 /* This is simply a safety net to avoid seg faults especially when
676 * using a user-space library. afs_SetPrimaryCell() should be set
677 * prior to this call. */
678 afs_SetPrimaryCell(cell->cellName);
681 return strcmp(cell->cellName, afs_thiscell) ? 0 : 1;
686 afs_IsPrimaryCellNum(afs_int32 cellnum)
691 tc = afs_GetCellStale(cellnum, READ_LOCK);
693 primary = afs_IsPrimaryCell(tc);
694 afs_PutCell(tc, READ_LOCK);
701 afs_SetPrimaryCell(char *acellName)
703 ObtainWriteLock(&afs_xcell, 691);
705 afs_osi_FreeStr(afs_thiscell);
706 afs_thiscell = afs_strdup(acellName);
707 ReleaseWriteLock(&afs_xcell);
712 afs_NewCell(char *acellName, afs_int32 * acellHosts, int aflags,
713 char *linkedcname, u_short fsport, u_short vlport, int timeout)
715 struct cell *tc, *tcl = 0;
716 afs_int32 i, newc = 0, code = 0;
718 AFS_STATCNT(afs_NewCell);
720 ObtainWriteLock(&afs_xcell, 103);
722 tc = afs_FindCellByName_nl(acellName, READ_LOCK);
726 tc = (struct cell *)afs_osi_Alloc(sizeof(struct cell));
727 memset((char *)tc, 0, sizeof(*tc));
728 tc->cellName = afs_strdup(acellName);
729 tc->fsport = AFS_FSPORT;
730 tc->vlport = AFS_VLPORT;
731 AFS_MD5_String(tc->cellHandle, tc->cellName, strlen(tc->cellName));
732 RWLOCK_INIT(&tc->lock, "cell lock");
736 ObtainWriteLock(&tc->lock, 688);
738 /* If the cell we've found has the correct name but no timeout,
739 * and we're called with a non-zero timeout, bail out: never
740 * override static configuration entries with AFSDB ones.
741 * One exception: if the original cell entry had no servers,
742 * it must get servers from AFSDB.
744 if (timeout && !tc->timeout && tc->cellHosts[0]) {
745 code = EEXIST; /* This code is checked for in afs_LookupAFSDB */
749 /* we don't want to keep pinging old vlservers which were down,
750 * since they don't matter any more. It's easier to do this than
751 * to remove the server from its various hash tables. */
752 for (i = 0; i < MAXCELLHOSTS; i++) {
753 if (!tc->cellHosts[i])
755 tc->cellHosts[i]->flags &= ~SRVR_ISDOWN;
756 tc->cellHosts[i]->flags |= SRVR_ISGONE;
764 if (aflags & CLinkedCell) {
769 tcl = afs_FindCellByName_nl(linkedcname, READ_LOCK);
774 if (tcl->lcellp) { /* XXX Overwriting if one existed before! XXX */
775 tcl->lcellp->lcellp = (struct cell *)0;
776 tcl->lcellp->states &= ~CLinkedCell;
781 tc->states |= aflags;
782 tc->timeout = timeout;
784 memset((char *)tc->cellHosts, 0, sizeof(tc->cellHosts));
785 for (i = 0; i < MAXCELLHOSTS; i++) {
787 afs_uint32 temp = acellHosts[i];
790 ts = afs_GetServer(&temp, 1, 0, tc->vlport, WRITE_LOCK, NULL, 0);
792 ts->flags &= ~SRVR_ISGONE;
793 tc->cellHosts[i] = ts;
794 afs_PutServer(ts, WRITE_LOCK);
796 afs_SortServers(tc->cellHosts, MAXCELLHOSTS); /* randomize servers */
799 struct cell_name *cn;
801 cn = afs_cellname_lookup_name(acellName);
803 cn = afs_cellname_new(acellName, 0);
806 tc->cellNum = cn->cellnum;
807 tc->cellIndex = afs_cellindex++;
808 afs_stats_cmperf.numCellsVisible++;
809 QAdd(&CellLRU, &tc->lruq);
812 ReleaseWriteLock(&tc->lock);
813 ReleaseWriteLock(&afs_xcell);
815 afs_DynrootInvalidate();
820 afs_osi_FreeStr(tc->cellName);
821 afs_osi_Free(tc, sizeof(struct cell));
823 ReleaseWriteLock(&tc->lock);
824 ReleaseWriteLock(&afs_xcell);
829 * Miscellaneous stuff
831 * afs_CellInit: perform whatever initialization is necessary
832 * shutdown_cell: called on shutdown, should deallocate memory, etc
833 * afs_RemoveCellEntry: remove a server from a cell's server list
834 * afs_CellOrAliasExists: check if the given name exists as a cell or alias
835 * afs_CellOrAliasExists_nl: same as above without locking afs_xcell
836 * afs_CellNumValid: check if a cell number is valid (also set the used flag)
842 RWLOCK_INIT(&afs_xcell, "afs_xcell");
844 RWLOCK_INIT(&afsdb_client_lock, "afsdb_client_lock");
845 RWLOCK_INIT(&afsdb_req_lock, "afsdb_req_lock");
850 afs_cellalias_index = 0;
856 struct afs_q *cq, *tq;
859 RWLOCK_INIT(&afs_xcell, "afs_xcell");
861 for (cq = CellLRU.next; cq != &CellLRU; cq = tq) {
865 afs_osi_FreeStr(tc->cellName);
866 afs_osi_Free(tc, sizeof(struct cell));
871 struct cell_name *cn = afs_cellname_head;
874 struct cell_name *next = cn->next;
876 afs_osi_FreeStr(cn->cellname);
877 afs_osi_Free(cn, sizeof(struct cell_name));
884 afs_RemoveCellEntry(struct server *srvp)
893 /* Remove the server structure from the cell list - if there */
894 ObtainWriteLock(&tc->lock, 200);
895 for (j = k = 0; j < MAXCELLHOSTS; j++) {
896 if (!tc->cellHosts[j])
898 if (tc->cellHosts[j] != srvp) {
899 tc->cellHosts[k++] = tc->cellHosts[j];
903 /* What do we do if we remove the last one? */
905 for (; k < MAXCELLHOSTS; k++) {
906 tc->cellHosts[k] = 0;
908 ReleaseWriteLock(&tc->lock);
912 afs_CellOrAliasExists_nl(char *aname)
915 struct cell_alias *ca;
917 c = afs_FindCellByName_nl(aname, READ_LOCK);
919 afs_PutCell(c, READ_LOCK);
923 ca = afs_FindCellAlias(aname);
925 afs_PutCellAlias(ca);
933 afs_CellOrAliasExists(char *aname)
937 ObtainReadLock(&afs_xcell);
938 ret = afs_CellOrAliasExists_nl(aname);
939 ReleaseReadLock(&afs_xcell);
945 afs_CellNumValid(afs_int32 cellnum)
947 struct cell_name *cn;
949 ObtainReadLock(&afs_xcell);
950 cn = afs_cellname_lookup_id(cellnum);
951 ReleaseReadLock(&afs_xcell);