1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate * CDDL HEADER START
3*0Sstevel@tonic-gate *
4*0Sstevel@tonic-gate * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance
7*0Sstevel@tonic-gate * with the License.
8*0Sstevel@tonic-gate *
9*0Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate * and limitations under the License.
13*0Sstevel@tonic-gate *
14*0Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate *
20*0Sstevel@tonic-gate * CDDL HEADER END
21*0Sstevel@tonic-gate */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
24*0Sstevel@tonic-gate * Use is subject to license terms.
25*0Sstevel@tonic-gate */
26*0Sstevel@tonic-gate
27*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI"
28*0Sstevel@tonic-gate
29*0Sstevel@tonic-gate #include <assert.h>
30*0Sstevel@tonic-gate #include <pthread.h>
31*0Sstevel@tonic-gate #include <stdlib.h>
32*0Sstevel@tonic-gate #include <strings.h>
33*0Sstevel@tonic-gate #include "configd.h"
34*0Sstevel@tonic-gate #include "repcache_protocol.h"
35*0Sstevel@tonic-gate
36*0Sstevel@tonic-gate typedef struct snapshot_bucket {
37*0Sstevel@tonic-gate pthread_mutex_t sb_lock;
38*0Sstevel@tonic-gate rc_snapshot_t *sb_head;
39*0Sstevel@tonic-gate
40*0Sstevel@tonic-gate char sb_pad[64 - sizeof (pthread_mutex_t) -
41*0Sstevel@tonic-gate sizeof (rc_snapshot_t *)];
42*0Sstevel@tonic-gate } snapshot_bucket_t;
43*0Sstevel@tonic-gate
44*0Sstevel@tonic-gate #define SN_HASH_SIZE 64
45*0Sstevel@tonic-gate #define SN_HASH_MASK (SN_HASH_SIZE - 1)
46*0Sstevel@tonic-gate
47*0Sstevel@tonic-gate #pragma align 64(snapshot_hash)
48*0Sstevel@tonic-gate static snapshot_bucket_t snapshot_hash[SN_HASH_SIZE];
49*0Sstevel@tonic-gate
50*0Sstevel@tonic-gate #define SNAPSHOT_BUCKET(h) (&snapshot_hash[(h) & SN_HASH_MASK])
51*0Sstevel@tonic-gate
52*0Sstevel@tonic-gate static rc_snapshot_t *
snapshot_alloc(void)53*0Sstevel@tonic-gate snapshot_alloc(void)
54*0Sstevel@tonic-gate {
55*0Sstevel@tonic-gate rc_snapshot_t *sp;
56*0Sstevel@tonic-gate sp = uu_zalloc(sizeof (*sp));
57*0Sstevel@tonic-gate
58*0Sstevel@tonic-gate (void) pthread_mutex_init(&sp->rs_lock, NULL);
59*0Sstevel@tonic-gate (void) pthread_cond_init(&sp->rs_cv, NULL);
60*0Sstevel@tonic-gate
61*0Sstevel@tonic-gate sp->rs_refcnt++;
62*0Sstevel@tonic-gate return (sp);
63*0Sstevel@tonic-gate }
64*0Sstevel@tonic-gate
65*0Sstevel@tonic-gate static void
snapshot_free(rc_snapshot_t * sp)66*0Sstevel@tonic-gate snapshot_free(rc_snapshot_t *sp)
67*0Sstevel@tonic-gate {
68*0Sstevel@tonic-gate rc_snaplevel_t *lvl, *next;
69*0Sstevel@tonic-gate
70*0Sstevel@tonic-gate assert(sp->rs_refcnt == 0 && sp->rs_childref == 0);
71*0Sstevel@tonic-gate
72*0Sstevel@tonic-gate (void) pthread_mutex_destroy(&sp->rs_lock);
73*0Sstevel@tonic-gate (void) pthread_cond_destroy(&sp->rs_cv);
74*0Sstevel@tonic-gate
75*0Sstevel@tonic-gate for (lvl = sp->rs_levels; lvl != NULL; lvl = next) {
76*0Sstevel@tonic-gate next = lvl->rsl_next;
77*0Sstevel@tonic-gate
78*0Sstevel@tonic-gate assert(lvl->rsl_parent == sp);
79*0Sstevel@tonic-gate lvl->rsl_parent = NULL;
80*0Sstevel@tonic-gate
81*0Sstevel@tonic-gate if (lvl->rsl_service)
82*0Sstevel@tonic-gate free((char *)lvl->rsl_service);
83*0Sstevel@tonic-gate if (lvl->rsl_instance)
84*0Sstevel@tonic-gate free((char *)lvl->rsl_instance);
85*0Sstevel@tonic-gate
86*0Sstevel@tonic-gate uu_free(lvl);
87*0Sstevel@tonic-gate }
88*0Sstevel@tonic-gate uu_free(sp);
89*0Sstevel@tonic-gate }
90*0Sstevel@tonic-gate
91*0Sstevel@tonic-gate static void
rc_snapshot_hold(rc_snapshot_t * sp)92*0Sstevel@tonic-gate rc_snapshot_hold(rc_snapshot_t *sp)
93*0Sstevel@tonic-gate {
94*0Sstevel@tonic-gate (void) pthread_mutex_lock(&sp->rs_lock);
95*0Sstevel@tonic-gate sp->rs_refcnt++;
96*0Sstevel@tonic-gate assert(sp->rs_refcnt > 0);
97*0Sstevel@tonic-gate (void) pthread_mutex_unlock(&sp->rs_lock);
98*0Sstevel@tonic-gate }
99*0Sstevel@tonic-gate
100*0Sstevel@tonic-gate void
rc_snapshot_rele(rc_snapshot_t * sp)101*0Sstevel@tonic-gate rc_snapshot_rele(rc_snapshot_t *sp)
102*0Sstevel@tonic-gate {
103*0Sstevel@tonic-gate int done;
104*0Sstevel@tonic-gate (void) pthread_mutex_lock(&sp->rs_lock);
105*0Sstevel@tonic-gate assert(sp->rs_refcnt > 0);
106*0Sstevel@tonic-gate sp->rs_refcnt--;
107*0Sstevel@tonic-gate done = ((sp->rs_flags & RC_SNAPSHOT_DEAD) &&
108*0Sstevel@tonic-gate sp->rs_refcnt == 0 && sp->rs_childref == 0);
109*0Sstevel@tonic-gate (void) pthread_mutex_unlock(&sp->rs_lock);
110*0Sstevel@tonic-gate
111*0Sstevel@tonic-gate if (done)
112*0Sstevel@tonic-gate snapshot_free(sp);
113*0Sstevel@tonic-gate }
114*0Sstevel@tonic-gate
115*0Sstevel@tonic-gate void
rc_snaplevel_hold(rc_snaplevel_t * lvl)116*0Sstevel@tonic-gate rc_snaplevel_hold(rc_snaplevel_t *lvl)
117*0Sstevel@tonic-gate {
118*0Sstevel@tonic-gate rc_snapshot_t *sp = lvl->rsl_parent;
119*0Sstevel@tonic-gate (void) pthread_mutex_lock(&sp->rs_lock);
120*0Sstevel@tonic-gate sp->rs_childref++;
121*0Sstevel@tonic-gate assert(sp->rs_childref > 0);
122*0Sstevel@tonic-gate (void) pthread_mutex_unlock(&sp->rs_lock);
123*0Sstevel@tonic-gate }
124*0Sstevel@tonic-gate
125*0Sstevel@tonic-gate void
rc_snaplevel_rele(rc_snaplevel_t * lvl)126*0Sstevel@tonic-gate rc_snaplevel_rele(rc_snaplevel_t *lvl)
127*0Sstevel@tonic-gate {
128*0Sstevel@tonic-gate int done;
129*0Sstevel@tonic-gate rc_snapshot_t *sp = lvl->rsl_parent;
130*0Sstevel@tonic-gate (void) pthread_mutex_lock(&sp->rs_lock);
131*0Sstevel@tonic-gate assert(sp->rs_childref > 0);
132*0Sstevel@tonic-gate sp->rs_childref--;
133*0Sstevel@tonic-gate done = ((sp->rs_flags & RC_SNAPSHOT_DEAD) &&
134*0Sstevel@tonic-gate sp->rs_refcnt == 0 && sp->rs_childref == 0);
135*0Sstevel@tonic-gate (void) pthread_mutex_unlock(&sp->rs_lock);
136*0Sstevel@tonic-gate
137*0Sstevel@tonic-gate if (done)
138*0Sstevel@tonic-gate snapshot_free(sp);
139*0Sstevel@tonic-gate }
140*0Sstevel@tonic-gate
141*0Sstevel@tonic-gate static snapshot_bucket_t *
snapshot_hold_bucket(uint32_t snap_id)142*0Sstevel@tonic-gate snapshot_hold_bucket(uint32_t snap_id)
143*0Sstevel@tonic-gate {
144*0Sstevel@tonic-gate snapshot_bucket_t *bp = SNAPSHOT_BUCKET(snap_id);
145*0Sstevel@tonic-gate (void) pthread_mutex_lock(&bp->sb_lock);
146*0Sstevel@tonic-gate return (bp);
147*0Sstevel@tonic-gate }
148*0Sstevel@tonic-gate
149*0Sstevel@tonic-gate static void
snapshot_rele_bucket(snapshot_bucket_t * bp)150*0Sstevel@tonic-gate snapshot_rele_bucket(snapshot_bucket_t *bp)
151*0Sstevel@tonic-gate {
152*0Sstevel@tonic-gate assert(MUTEX_HELD(&bp->sb_lock));
153*0Sstevel@tonic-gate (void) pthread_mutex_unlock(&bp->sb_lock);
154*0Sstevel@tonic-gate }
155*0Sstevel@tonic-gate
156*0Sstevel@tonic-gate static rc_snapshot_t *
snapshot_lookup_unlocked(snapshot_bucket_t * bp,uint32_t snap_id)157*0Sstevel@tonic-gate snapshot_lookup_unlocked(snapshot_bucket_t *bp, uint32_t snap_id)
158*0Sstevel@tonic-gate {
159*0Sstevel@tonic-gate rc_snapshot_t *sp;
160*0Sstevel@tonic-gate
161*0Sstevel@tonic-gate assert(MUTEX_HELD(&bp->sb_lock));
162*0Sstevel@tonic-gate assert(bp == SNAPSHOT_BUCKET(snap_id));
163*0Sstevel@tonic-gate
164*0Sstevel@tonic-gate for (sp = bp->sb_head; sp != NULL; sp = sp->rs_hash_next) {
165*0Sstevel@tonic-gate if (sp->rs_snap_id == snap_id) {
166*0Sstevel@tonic-gate rc_snapshot_hold(sp);
167*0Sstevel@tonic-gate return (sp);
168*0Sstevel@tonic-gate }
169*0Sstevel@tonic-gate }
170*0Sstevel@tonic-gate return (NULL);
171*0Sstevel@tonic-gate }
172*0Sstevel@tonic-gate
173*0Sstevel@tonic-gate static void
snapshot_insert_unlocked(snapshot_bucket_t * bp,rc_snapshot_t * sp)174*0Sstevel@tonic-gate snapshot_insert_unlocked(snapshot_bucket_t *bp, rc_snapshot_t *sp)
175*0Sstevel@tonic-gate {
176*0Sstevel@tonic-gate assert(MUTEX_HELD(&bp->sb_lock));
177*0Sstevel@tonic-gate assert(bp == SNAPSHOT_BUCKET(sp->rs_snap_id));
178*0Sstevel@tonic-gate
179*0Sstevel@tonic-gate assert(sp->rs_hash_next == NULL);
180*0Sstevel@tonic-gate
181*0Sstevel@tonic-gate sp->rs_hash_next = bp->sb_head;
182*0Sstevel@tonic-gate bp->sb_head = sp;
183*0Sstevel@tonic-gate }
184*0Sstevel@tonic-gate
185*0Sstevel@tonic-gate static void
snapshot_remove_unlocked(snapshot_bucket_t * bp,rc_snapshot_t * sp)186*0Sstevel@tonic-gate snapshot_remove_unlocked(snapshot_bucket_t *bp, rc_snapshot_t *sp)
187*0Sstevel@tonic-gate {
188*0Sstevel@tonic-gate rc_snapshot_t **spp;
189*0Sstevel@tonic-gate
190*0Sstevel@tonic-gate assert(MUTEX_HELD(&bp->sb_lock));
191*0Sstevel@tonic-gate assert(bp == SNAPSHOT_BUCKET(sp->rs_snap_id));
192*0Sstevel@tonic-gate
193*0Sstevel@tonic-gate assert(sp->rs_hash_next == NULL);
194*0Sstevel@tonic-gate
195*0Sstevel@tonic-gate for (spp = &bp->sb_head; *spp != NULL; spp = &(*spp)->rs_hash_next)
196*0Sstevel@tonic-gate if (*spp == sp)
197*0Sstevel@tonic-gate break;
198*0Sstevel@tonic-gate
199*0Sstevel@tonic-gate assert(*spp == sp);
200*0Sstevel@tonic-gate *spp = sp->rs_hash_next;
201*0Sstevel@tonic-gate sp->rs_hash_next = NULL;
202*0Sstevel@tonic-gate }
203*0Sstevel@tonic-gate
204*0Sstevel@tonic-gate /*
205*0Sstevel@tonic-gate * Look up the snapshot with id snap_id in the hash table, or create it
206*0Sstevel@tonic-gate * & populate it with its snaplevels if it's not in the hash table yet.
207*0Sstevel@tonic-gate *
208*0Sstevel@tonic-gate * Fails with
209*0Sstevel@tonic-gate * _NO_RESOURCES
210*0Sstevel@tonic-gate */
211*0Sstevel@tonic-gate int
rc_snapshot_get(uint32_t snap_id,rc_snapshot_t ** snpp)212*0Sstevel@tonic-gate rc_snapshot_get(uint32_t snap_id, rc_snapshot_t **snpp)
213*0Sstevel@tonic-gate {
214*0Sstevel@tonic-gate snapshot_bucket_t *bp;
215*0Sstevel@tonic-gate rc_snapshot_t *sp;
216*0Sstevel@tonic-gate int r;
217*0Sstevel@tonic-gate
218*0Sstevel@tonic-gate bp = snapshot_hold_bucket(snap_id);
219*0Sstevel@tonic-gate sp = snapshot_lookup_unlocked(bp, snap_id);
220*0Sstevel@tonic-gate if (sp != NULL) {
221*0Sstevel@tonic-gate snapshot_rele_bucket(bp);
222*0Sstevel@tonic-gate (void) pthread_mutex_lock(&sp->rs_lock);
223*0Sstevel@tonic-gate while (sp->rs_flags & RC_SNAPSHOT_FILLING)
224*0Sstevel@tonic-gate (void) pthread_cond_wait(&sp->rs_cv, &sp->rs_lock);
225*0Sstevel@tonic-gate
226*0Sstevel@tonic-gate if (sp->rs_flags & RC_SNAPSHOT_DEAD) {
227*0Sstevel@tonic-gate (void) pthread_mutex_unlock(&sp->rs_lock);
228*0Sstevel@tonic-gate rc_snapshot_rele(sp);
229*0Sstevel@tonic-gate return (REP_PROTOCOL_FAIL_NO_RESOURCES);
230*0Sstevel@tonic-gate }
231*0Sstevel@tonic-gate assert(sp->rs_flags & RC_SNAPSHOT_READY);
232*0Sstevel@tonic-gate (void) pthread_mutex_unlock(&sp->rs_lock);
233*0Sstevel@tonic-gate *snpp = sp;
234*0Sstevel@tonic-gate return (REP_PROTOCOL_SUCCESS);
235*0Sstevel@tonic-gate }
236*0Sstevel@tonic-gate sp = snapshot_alloc();
237*0Sstevel@tonic-gate sp->rs_snap_id = snap_id;
238*0Sstevel@tonic-gate sp->rs_flags |= RC_SNAPSHOT_FILLING;
239*0Sstevel@tonic-gate snapshot_insert_unlocked(bp, sp);
240*0Sstevel@tonic-gate snapshot_rele_bucket(bp);
241*0Sstevel@tonic-gate
242*0Sstevel@tonic-gate /*
243*0Sstevel@tonic-gate * Now fill in the snapshot tree
244*0Sstevel@tonic-gate */
245*0Sstevel@tonic-gate r = object_fill_snapshot(sp);
246*0Sstevel@tonic-gate if (r != REP_PROTOCOL_SUCCESS) {
247*0Sstevel@tonic-gate assert(r == REP_PROTOCOL_FAIL_NO_RESOURCES);
248*0Sstevel@tonic-gate
249*0Sstevel@tonic-gate /*
250*0Sstevel@tonic-gate * failed -- first remove it from the hash table, then kill it
251*0Sstevel@tonic-gate */
252*0Sstevel@tonic-gate bp = snapshot_hold_bucket(snap_id);
253*0Sstevel@tonic-gate snapshot_remove_unlocked(bp, sp);
254*0Sstevel@tonic-gate snapshot_rele_bucket(bp);
255*0Sstevel@tonic-gate
256*0Sstevel@tonic-gate (void) pthread_mutex_lock(&sp->rs_lock);
257*0Sstevel@tonic-gate sp->rs_flags &= ~RC_SNAPSHOT_FILLING;
258*0Sstevel@tonic-gate sp->rs_flags |= RC_SNAPSHOT_DEAD;
259*0Sstevel@tonic-gate (void) pthread_cond_broadcast(&sp->rs_cv);
260*0Sstevel@tonic-gate (void) pthread_mutex_unlock(&sp->rs_lock);
261*0Sstevel@tonic-gate rc_snapshot_rele(sp); /* may free sp */
262*0Sstevel@tonic-gate return (r);
263*0Sstevel@tonic-gate }
264*0Sstevel@tonic-gate (void) pthread_mutex_lock(&sp->rs_lock);
265*0Sstevel@tonic-gate sp->rs_flags &= ~RC_SNAPSHOT_FILLING;
266*0Sstevel@tonic-gate sp->rs_flags |= RC_SNAPSHOT_READY;
267*0Sstevel@tonic-gate (void) pthread_cond_broadcast(&sp->rs_cv);
268*0Sstevel@tonic-gate (void) pthread_mutex_unlock(&sp->rs_lock);
269*0Sstevel@tonic-gate *snpp = sp;
270*0Sstevel@tonic-gate return (REP_PROTOCOL_SUCCESS); /* pass on creation reference */
271*0Sstevel@tonic-gate }
272