Date: Wed, 19 Aug 2009 00:10:11 +0000 (UTC) From: Max Laier <mlaier@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r196372 - head/sys/contrib/pf/net Message-ID: <200908190010.n7J0ABEk032189@svn.freebsd.org>
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Author: mlaier Date: Wed Aug 19 00:10:10 2009 New Revision: 196372 URL: http://svn.freebsd.org/changeset/base/196372 Log: If we cannot immediately get the pf_consistency_lock in the purge thread, restart the scan after acquiring the lock the hard way. Otherwise we might end up with a dead reference. Reported by: pfsense Reviewed by: eri Initial patch by: eri Tested by: pfsense Approved by: re (kib) Modified: head/sys/contrib/pf/net/pf.c head/sys/contrib/pf/net/pfvar.h Modified: head/sys/contrib/pf/net/pf.c ============================================================================== --- head/sys/contrib/pf/net/pf.c Tue Aug 18 21:13:00 2009 (r196371) +++ head/sys/contrib/pf/net/pf.c Wed Aug 19 00:10:10 2009 (r196372) @@ -971,6 +971,9 @@ void pf_purge_thread(void *v) { int nloops = 0, s; +#ifdef __FreeBSD__ + int locked; +#endif for (;;) { tsleep(pf_purge_thread, PWAIT, "pftm", 1 * hz); @@ -978,14 +981,19 @@ pf_purge_thread(void *v) #ifdef __FreeBSD__ sx_slock(&pf_consistency_lock); PF_LOCK(); + locked = 0; if (pf_end_threads) { - pf_purge_expired_states(pf_status.states); + PF_UNLOCK(); + sx_sunlock(&pf_consistency_lock); + sx_xlock(&pf_consistency_lock); + PF_LOCK(); + pf_purge_expired_states(pf_status.states, 1); pf_purge_expired_fragments(); - pf_purge_expired_src_nodes(0); + pf_purge_expired_src_nodes(1); pf_end_threads++; - sx_sunlock(&pf_consistency_lock); + sx_xunlock(&pf_consistency_lock); PF_UNLOCK(); wakeup(pf_purge_thread); kproc_exit(0); @@ -994,20 +1002,44 @@ pf_purge_thread(void *v) s = splsoftnet(); /* process a fraction of the state table every second */ +#ifdef __FreeBSD__ + if(!pf_purge_expired_states(1 + (pf_status.states + / pf_default_rule.timeout[PFTM_INTERVAL]), 0)) { + PF_UNLOCK(); + sx_sunlock(&pf_consistency_lock); + sx_xlock(&pf_consistency_lock); + PF_LOCK(); + locked = 1; + + pf_purge_expired_states(1 + (pf_status.states + / pf_default_rule.timeout[PFTM_INTERVAL]), 1); + } +#else pf_purge_expired_states(1 + (pf_status.states / pf_default_rule.timeout[PFTM_INTERVAL])); +#endif /* purge other expired types every PFTM_INTERVAL seconds */ if (++nloops >= pf_default_rule.timeout[PFTM_INTERVAL]) { pf_purge_expired_fragments(); - pf_purge_expired_src_nodes(0); + if (!pf_purge_expired_src_nodes(locked)) { + PF_UNLOCK(); + sx_sunlock(&pf_consistency_lock); + sx_xlock(&pf_consistency_lock); + PF_LOCK(); + locked = 1; + pf_purge_expired_src_nodes(1); + } nloops = 0; } splx(s); #ifdef __FreeBSD__ PF_UNLOCK(); - sx_sunlock(&pf_consistency_lock); + if (locked) + sx_xunlock(&pf_consistency_lock); + else + sx_sunlock(&pf_consistency_lock); #endif } } @@ -1056,8 +1088,13 @@ pf_state_expires(const struct pf_state * return (state->expire + timeout); } +#ifdef __FreeBSD__ +int +pf_purge_expired_src_nodes(int waslocked) +#else void pf_purge_expired_src_nodes(int waslocked) +#endif { struct pf_src_node *cur, *next; int locked = waslocked; @@ -1068,12 +1105,8 @@ pf_purge_expired_src_nodes(int waslocked if (cur->states <= 0 && cur->expire <= time_second) { if (! locked) { #ifdef __FreeBSD__ - if (!sx_try_upgrade(&pf_consistency_lock)) { - PF_UNLOCK(); - sx_sunlock(&pf_consistency_lock); - sx_xlock(&pf_consistency_lock); - PF_LOCK(); - } + if (!sx_try_upgrade(&pf_consistency_lock)) + return (0); #else rw_enter_write(&pf_consistency_lock); #endif @@ -1100,6 +1133,10 @@ pf_purge_expired_src_nodes(int waslocked #else rw_exit_write(&pf_consistency_lock); #endif + +#ifdef __FreeBSD__ + return (1); +#endif } void @@ -1202,12 +1239,21 @@ pf_free_state(struct pf_state *cur) pf_status.states--; } +#ifdef __FreeBSD__ +int +pf_purge_expired_states(u_int32_t maxcheck, int waslocked) +#else void pf_purge_expired_states(u_int32_t maxcheck) +#endif { static struct pf_state *cur = NULL; struct pf_state *next; +#ifdef __FreeBSD__ + int locked = waslocked; +#else int locked = 0; +#endif while (maxcheck--) { /* wrap to start of list when we hit the end */ @@ -1224,12 +1270,8 @@ pf_purge_expired_states(u_int32_t maxche /* free unlinked state */ if (! locked) { #ifdef __FreeBSD__ - if (!sx_try_upgrade(&pf_consistency_lock)) { - PF_UNLOCK(); - sx_sunlock(&pf_consistency_lock); - sx_xlock(&pf_consistency_lock); - PF_LOCK(); - } + if (!sx_try_upgrade(&pf_consistency_lock)) + return (0); #else rw_enter_write(&pf_consistency_lock); #endif @@ -1241,12 +1283,8 @@ pf_purge_expired_states(u_int32_t maxche pf_unlink_state(cur); if (! locked) { #ifdef __FreeBSD__ - if (!sx_try_upgrade(&pf_consistency_lock)) { - PF_UNLOCK(); - sx_sunlock(&pf_consistency_lock); - sx_xlock(&pf_consistency_lock); - PF_LOCK(); - } + if (!sx_try_upgrade(&pf_consistency_lock)) + return (0); #else rw_enter_write(&pf_consistency_lock); #endif @@ -1257,10 +1295,13 @@ pf_purge_expired_states(u_int32_t maxche cur = next; } - if (locked) #ifdef __FreeBSD__ + if (!waslocked && locked) sx_downgrade(&pf_consistency_lock); + + return (1); #else + if (locked) rw_exit_write(&pf_consistency_lock); #endif } Modified: head/sys/contrib/pf/net/pfvar.h ============================================================================== --- head/sys/contrib/pf/net/pfvar.h Tue Aug 18 21:13:00 2009 (r196371) +++ head/sys/contrib/pf/net/pfvar.h Wed Aug 19 00:10:10 2009 (r196372) @@ -1593,8 +1593,13 @@ extern struct pool pf_state_pl, pf_alt extern struct pool pf_state_scrub_pl; #endif extern void pf_purge_thread(void *); +#ifdef __FreeBSD__ +extern int pf_purge_expired_src_nodes(int); +extern int pf_purge_expired_states(u_int32_t, int); +#else extern void pf_purge_expired_src_nodes(int); extern void pf_purge_expired_states(u_int32_t); +#endif extern void pf_unlink_state(struct pf_state *); extern void pf_free_state(struct pf_state *); extern int pf_insert_state(struct pfi_kif *,
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