3f5ba2218 libpcp_web: add mutex to struct webgroup protecting the context dict

107633192 src/libpcp: be more careful when calling __pmLogChangeVol()

49bdfdfff libpcp: redefine __pmLogSetTime()

5e3b792d3 libpcp_web: plug mem leak in redisMapInsert during daily log-rolling

2a00a90b0 libpcp_web/discovery: improve lock handling and scalability

commit 3f5ba221842e6a02e9fb22e23c754854271c3c9a

Author: Mark Goodwin <mgoodwin@redhat.com>

Date:   Wed Jun 9 16:44:30 2021 +1000

    libpcp_web: add mutex to struct webgroup protecting the context dict

    Add a mutex to the local webgroups structure in libpcp_web and

    use it to protect multithreaded parallel updates (dictAdd,

    dictDelete) to the groups->contexts dict and the dict traversal

    in the timer driven garbage collector.

    Tested by qa/297 and related tests and also an updated version

    of qa/1457 (which now stress tests parallel http and https/tls

    pmproxy RESTAPI calls .. in a later commit).

    Related: RHBZ#1947989

    Resolves: https://github.com/performancecopilot/pcp/issues/1311

diff --git a/src/libpcp_web/src/webgroup.c b/src/libpcp_web/src/webgroup.c

index 08c2518ed..35f05441b 100644

--- a/src/libpcp_web/src/webgroup.c

+++ b/src/libpcp_web/src/webgroup.c

@@ -51,14 +51,20 @@ typedef struct webgroups {

     uv_loop_t		*events;

     unsigned int	active;

     uv_timer_t		timer;

+    uv_mutex_t		mutex;

 } webgroups;

 static struct webgroups *

 webgroups_lookup(pmWebGroupModule *module)

 {

-    if (module->privdata == NULL)

+    struct webgroups *groups = module->privdata;

+

+    if (module->privdata == NULL) {

 	module->privdata = calloc(1, sizeof(struct webgroups));

-    return (struct webgroups *)module->privdata;

+	groups = (struct webgroups *)module->privdata;

+	uv_mutex_init(&groups->mutex);

+    }

+    return groups;

 }

 static int

@@ -94,8 +100,11 @@ webgroup_drop_context(struct context *context, struct webgroups *groups)

 	    context->garbage = 1;

 	    uv_timer_stop(&context->timer);

 	}

-	if (groups)

+	if (groups) {

+	    uv_mutex_lock(&groups->mutex);

 	    dictDelete(groups->contexts, &context->randomid);

+	    uv_mutex_unlock(&groups->mutex);

+	}

 	uv_close((uv_handle_t *)&context->timer, webgroup_release_context);

     }

 }

@@ -207,13 +216,16 @@ webgroup_new_context(pmWebGroupSettings *sp, dict *params,

     cp->context = -1;

     cp->timeout = polltime;

+    uv_mutex_lock(&groups->mutex);

     if ((cp->randomid = random()) < 0 ||

 	dictFind(groups->contexts, &cp->randomid) != NULL) {

 	infofmt(*message, "random number failure on new web context");

 	pmwebapi_free_context(cp);

 	*status = -ESRCH;

+	uv_mutex_unlock(&groups->mutex);

 	return NULL;

     }

+    uv_mutex_unlock(&groups->mutex);

     cp->origin = sdscatfmt(sdsempty(), "%i", cp->randomid);

     cp->name.sds = sdsdup(hostspec ? hostspec : LOCALHOST);

     cp->realm = sdscatfmt(sdsempty(), "pmapi/%i", cp->randomid);

@@ -242,7 +254,9 @@ webgroup_new_context(pmWebGroupSettings *sp, dict *params,

 	pmwebapi_free_context(cp);

 	return NULL;

     }

+    uv_mutex_lock(&groups->mutex);

     dictAdd(groups->contexts, &cp->randomid, cp);

+    uv_mutex_unlock(&groups->mutex);

     /* leave until the end because uv_timer_init makes this visible in uv_run */

     handle = (uv_handle_t *)&cp->timer;

@@ -261,25 +275,34 @@ webgroup_new_context(pmWebGroupSettings *sp, dict *params,

 static void

 webgroup_garbage_collect(struct webgroups *groups)

 {

-    dictIterator        *iterator = dictGetSafeIterator(groups->contexts);

+    dictIterator        *iterator;

     dictEntry           *entry;

     context_t		*cp;

     if (pmDebugOptions.http || pmDebugOptions.libweb)

 	fprintf(stderr, "%s: started\n", "webgroup_garbage_collect");

-    while ((entry = dictNext(iterator)) != NULL) {

-	cp = (context_t *)dictGetVal(entry);

-	if (cp->garbage && cp->privdata == groups) {

-	    if (pmDebugOptions.http || pmDebugOptions.libweb)

-		fprintf(stderr, "GC context %u (%p)\n", cp->randomid, cp);

-	    webgroup_drop_context(cp, groups);

+    /* do context GC if we get the lock (else don't block here) */

+    if (uv_mutex_trylock(&groups->mutex) == 0) {

+	iterator = dictGetSafeIterator(groups->contexts);

+	for (entry = dictNext(iterator); entry;) {

+	    cp = (context_t *)dictGetVal(entry);

+	    entry = dictNext(iterator);

+	    if (cp->garbage && cp->privdata == groups) {

+		if (pmDebugOptions.http || pmDebugOptions.libweb)

+		    fprintf(stderr, "GC context %u (%p)\n", cp->randomid, cp);

+		uv_mutex_unlock(&groups->mutex);

+		webgroup_drop_context(cp, groups);

+		uv_mutex_lock(&groups->mutex);

+	    }

 	}

+	dictReleaseIterator(iterator);

+	uv_mutex_unlock(&groups->mutex);

     }

-    dictReleaseIterator(iterator);

     /* TODO - trim maps, particularly instmap if proc metrics are not excluded */

+    /* TODO move the following to a new stats timer */

     if (groups->metrics_handle) {

 	mmv_stats_set(groups->metrics_handle, "contextmap.size",

 	    NULL, dictSize(contextmap));

commit 107633192326b27ae571d4d4955052b8d86222c2

Author: Ken McDonell <kenj@kenj.id.au>

Date:   Fri Jul 2 16:52:48 2021 +1000

    src/libpcp: be more careful when calling __pmLogChangeVol()

    Mark observed a SEGV which looks like __pmLogFetch() died because

    ctxp->c_archctl->ac_mfp was (unexpectedly) NULL.

    See: https://github.com/performancecopilot/pcp/issues/1338

    Initial guess is that a physical file was removed by concurrent

    activity (like pmlogger_check or pmlogger_daily), causing

    __pmLogChangeVol() to fail ... and this was not being checked for

    on the __pmLogFetch() path and in a couple of other places.

    modified:   interp.c

    modified:   logutil.c

diff --git a/src/libpcp/src/interp.c b/src/libpcp/src/interp.c

index d7effbc1e..c8f6fe382 100644

--- a/src/libpcp/src/interp.c

+++ b/src/libpcp/src/interp.c

@@ -1312,7 +1312,9 @@ __pmLogFetchInterp(__pmContext *ctxp, int numpmid, pmID pmidlist[], pmResult **r

     }

     /* get to the last remembered place */

-    __pmLogChangeVol(ctxp->c_archctl, ctxp->c_archctl->ac_vol);

+    sts = __pmLogChangeVol(ctxp->c_archctl, ctxp->c_archctl->ac_vol);

+    if (sts < 0)

+	goto all_done;

     __pmFseek(ctxp->c_archctl->ac_mfp, ctxp->c_archctl->ac_offset, SEEK_SET);

     seen_mark = 0;	/* interested in <mark> records seen from here on */

@@ -1397,7 +1399,9 @@ __pmLogFetchInterp(__pmContext *ctxp, int numpmid, pmID pmidlist[], pmResult **r

 	 * at least one metric requires a bound from earlier in the log ...

 	 * position ourselves, ... and search

 	 */

-	__pmLogChangeVol(ctxp->c_archctl, ctxp->c_archctl->ac_vol);

+	sts = __pmLogChangeVol(ctxp->c_archctl, ctxp->c_archctl->ac_vol);

+	if (sts < 0)

+	    goto all_done;

 	__pmFseek(ctxp->c_archctl->ac_mfp, ctxp->c_archctl->ac_offset, SEEK_SET);

 	done = 0;

@@ -1542,7 +1546,9 @@ __pmLogFetchInterp(__pmContext *ctxp, int numpmid, pmID pmidlist[], pmResult **r

 	 * at least one metric requires a bound from later in the log ...

 	 * position ourselves ... and search

 	 */

-	__pmLogChangeVol(ctxp->c_archctl, ctxp->c_archctl->ac_vol);

+	sts = __pmLogChangeVol(ctxp->c_archctl, ctxp->c_archctl->ac_vol);

+	if (sts < 0)

+	    goto all_done;

 	__pmFseek(ctxp->c_archctl->ac_mfp, ctxp->c_archctl->ac_offset, SEEK_SET);

 	done = 0;

diff --git a/src/libpcp/src/logutil.c b/src/libpcp/src/logutil.c

index fe35ed422..0ef76de25 100644

--- a/src/libpcp/src/logutil.c

+++ b/src/libpcp/src/logutil.c

@@ -1992,7 +1992,10 @@ __pmLogFetch(__pmContext *ctxp, int numpmid, pmID pmidlist[], pmResult **result)

     all_derived = check_all_derived(numpmid, pmidlist);

     /* re-establish position */

-    __pmLogChangeVol(ctxp->c_archctl, ctxp->c_archctl->ac_vol);

+    sts = __pmLogChangeVol(ctxp->c_archctl, ctxp->c_archctl->ac_vol);

+    if (sts < 0)

+	goto func_return;

+    assert(ctxp->c_archctl->ac_mfp != NULL);

     __pmFseek(ctxp->c_archctl->ac_mfp, 

 	    (long)ctxp->c_archctl->ac_offset, SEEK_SET);

@@ -2489,10 +2492,12 @@ __pmLogSetTime(__pmContext *ctxp)

 	/* index either not available, or not useful */

 	if (mode == PM_MODE_FORW) {

 	    __pmLogChangeVol(acp, lcp->l_minvol);

+	    assert(acp->ac_mfp != NULL);

 	    __pmFseek(acp->ac_mfp, (long)(sizeof(__pmLogLabel) + 2*sizeof(int)), SEEK_SET);

 	}

 	else if (mode == PM_MODE_BACK) {

 	    __pmLogChangeVol(acp, lcp->l_maxvol);

+	    assert(acp->ac_mfp != NULL);

 	    __pmFseek(acp->ac_mfp, (long)0, SEEK_END);

 	}

@@ -3141,6 +3146,7 @@ LogChangeToPreviousArchive(__pmContext *ctxp)

     /* Set up to scan backwards from the end of the archive. */

     __pmLogChangeVol(acp, lcp->l_maxvol);

+    assert(acp->ac_mfp != NULL);

     __pmFseek(acp->ac_mfp, (long)0, SEEK_END);

     ctxp->c_archctl->ac_offset = __pmFtell(acp->ac_mfp);

     assert(ctxp->c_archctl->ac_offset >= 0);

commit 49bdfdfff83ac165de2bdc9a40e61a56512585d8

Author: Ken McDonell <kenj@kenj.id.au>

Date:   Sun Jul 4 10:07:09 2021 +1000

    libpcp: redefine __pmLogSetTime()

    The problem is that if physical files for the data volumes of an

    archive are removed (asynchronously by someone else) while we're

    trying to switch volumes then we don't handle this safely.

    The previous commit 10763319 was as stop-gap to address Mark's SEGV

    issue at https://github.com/performancecopilot/pcp/issues/1338 and

    simply handled direct calls to __pmLogChangeVol() and ensured the

    return status was checked.

    I was aware, then Coverity made a lot more people aware, that this

    "fix" was incomplete, specifically the calls to __pmLogChangeVol()

    from within __pmLogSetTime() were not checked.

    To fix the latter we have to change the type of __pmLogSetTime() from

    void to int so we can return status to indicate that __pmLogChangeVol()

    has failed.  And then make sure all the callers of __pmLogSetTime()

    check the status returned from that function.

        modified:   src/libpcp/src/fetch.c

        modified:   src/libpcp/src/internal.h

        modified:   src/libpcp/src/logutil.c

    Because this introduces some new -Dlog diagnostics, qa/251 needed

    a bit of a make-over.

diff --git a/qa/251 b/qa/251

index 2b8a07917..f9b293e98 100755

--- a/qa/251

+++ b/qa/251

@@ -37,7 +37,7 @@ _filter()

 status=1	# failure is the default!

 $sudo rm -rf $tmp.* $seq.full

-trap "cd $here; rm -rf $tmp; exit \$status" 0 1 2 3 15

+trap "cd $here; rm -rf $tmp $tmp.*; exit \$status" 0 1 2 3 15

 # real QA test starts here

 mkdir $tmp

@@ -50,56 +50,62 @@ cd $tmp

 for inst in "bin-100" "bin-100,bin-500,bin-900"

 do

     echo

-    echo "All volumes present ... $inst ..."

-    pmval -z -O $offset -D128 -t2 -a ok-mv-bar -i $inst sampledso.bin 2>err >out

-    egrep 'Skip|Change' err

-    _filter 

+    echo "All volumes present ... $inst ..." | tee -a $here/$seq.full

+    pmval -z -O $offset -Dlog -t2 -a ok-mv-bar -i $inst sampledso.bin 2>$tmp.err >$tmp.out

+    cat $tmp.err >>$here/$seq.full

+    grep '^__pmLogChangeVol:' $tmp.err

+    _filter <$tmp.out

     [ -f die ] && exit

     echo

-    echo "First volume missing ... $inst ..."

+    echo "First volume missing ... $inst ..." | tee -a $here/$seq.full

     mv ok-mv-bar.0 foo.0

-    pmval -z -O $offset -D128 -t2 -a ok-mv-bar -i $inst sampledso.bin 2>err >out

-    egrep 'Skip|Change' err

-    _filter 

+    pmval -z -O $offset -Dlog -t2 -a ok-mv-bar -i $inst sampledso.bin 2>$tmp.err >$tmp.out

+    cat $tmp.err >>$here/$seq.full

+    grep '^__pmLogChangeVol:' $tmp.err

+    _filter <$tmp.out

     [ -f die ] && exit

     mv foo.0 ok-mv-bar.0

     echo

-    echo "Last volume missing ... $inst ..."

+    echo "Last volume missing ... $inst ..." | tee -a $here/$seq.full

     mv ok-mv-bar.3 foo.3

-    pmval -z -O $offset -D128 -t2 -a ok-mv-bar -i $inst sampledso.bin 2>err >out

-    egrep 'Skip|Change' err

-    _filter 

+    pmval -z -O $offset -Dlog -t2 -a ok-mv-bar -i $inst sampledso.bin 2>$tmp.err >$tmp.out

+    cat $tmp.err >>$here/$seq.full

+    grep '^__pmLogChangeVol:' $tmp.err

+    _filter <$tmp.out

     [ -f die ] && exit

     mv foo.3 ok-mv-bar.3

     echo

-    echo "Second volume missing ... $inst ..."

+    echo "Second volume missing ... $inst ..." | tee -a $here/$seq.full

     mv ok-mv-bar.1 foo.1

-    pmval -z -O $offset -D128 -t2 -a ok-mv-bar -i $inst sampledso.bin 2>err >out

-    egrep 'Skip|Change' err

-    _filter 

+    pmval -z -O $offset -Dlog -t2 -a ok-mv-bar -i $inst sampledso.bin 2>$tmp.err >$tmp.out

+    cat $tmp.err >>$here/$seq.full

+    grep '^__pmLogChangeVol:' $tmp.err

+    _filter <$tmp.out

     [ -f die ] && exit

     mv foo.1 ok-mv-bar.1

     echo

-    echo "Second last volume missing ... $inst ..."

+    echo "Second last volume missing ... $inst ..." | tee -a $here/$seq.full

     mv ok-mv-bar.2 foo.2

-    pmval -z -O $offset -D128 -t2 -a ok-mv-bar -i $inst sampledso.bin 2>err >out

-    egrep 'Skip|Change' err

-    _filter 

+    pmval -z -O $offset -Dlog -t2 -a ok-mv-bar -i $inst sampledso.bin 2>$tmp.err >$tmp.out

+    cat $tmp.err >>$here/$seq.full

+    grep '^__pmLogChangeVol:' $tmp.err

+    _filter <$tmp.out

     [ -f die ] && exit

     mv foo.2 ok-mv-bar.2

     echo

-    echo "All volumes but second missing ... $inst ..."

+    echo "All volumes but second missing ... $inst ..." | tee -a $here/$seq.full

     mv ok-mv-bar.0 foo.0

     mv ok-mv-bar.2 foo.2

     mv ok-mv-bar.3 foo.3

-    pmval -z -O $offset -D128 -t2 -a ok-mv-bar -i $inst sampledso.bin 2>err >out

-    egrep 'Skip|Change' err

-    _filter 

+    pmval -z -O $offset -Dlog -t2 -a ok-mv-bar -i $inst sampledso.bin 2>$tmp.err >$tmp.out

+    cat $tmp.err >>$here/$seq.full

+    grep '^__pmLogChangeVol:' $tmp.err

+    _filter <$tmp.out

     [ -f die ] && exit

     mv foo.0 ok-mv-bar.0

     mv foo.2 ok-mv-bar.2

diff --git a/src/libpcp/src/fetch.c b/src/libpcp/src/fetch.c

index 5328a2807..01d5bf7fc 100644

--- a/src/libpcp/src/fetch.c

+++ b/src/libpcp/src/fetch.c

@@ -458,6 +458,7 @@ pmSetMode(int mode, const struct timeval *when, int delta)

 	    /* assume PM_CONTEXT_ARCHIVE */

 	    if (l_mode == PM_MODE_INTERP ||

 		l_mode == PM_MODE_FORW || l_mode == PM_MODE_BACK) {

+		int	lsts;

 		if (when != NULL) {

 		    /*

 		     * special case of NULL for timestamp

@@ -468,7 +469,18 @@ pmSetMode(int mode, const struct timeval *when, int delta)

 		}

 		ctxp->c_mode = mode;

 		ctxp->c_delta = delta;

-		__pmLogSetTime(ctxp);

+		lsts = __pmLogSetTime(ctxp);

+		if (lsts < 0) {

+		    /*

+		     * most unlikely; not much we can do here but expect

+		     * PMAPI error to be returned once pmFetch's start

+		     */

+		    if (pmDebugOptions.log) {

+			char	errmsg[PM_MAXERRMSGLEN];

+			fprintf(stderr, "pmSetMode: __pmLogSetTime failed: %s\n",

+			    pmErrStr_r(lsts, errmsg, sizeof(errmsg)));

+		    }

+		}

 		__pmLogResetInterp(ctxp);

 		sts = 0;

 	    }

diff --git a/src/libpcp/src/internal.h b/src/libpcp/src/internal.h

index 977efdcf6..fd8d6e740 100644

--- a/src/libpcp/src/internal.h

+++ b/src/libpcp/src/internal.h

@@ -407,7 +407,7 @@ extern int __pmLogGenerateMark(__pmLogCtl *, int, pmResult **) _PCP_HIDDEN;

 extern int __pmLogFetchInterp(__pmContext *, int, pmID *, pmResult **) _PCP_HIDDEN;

 extern int __pmGetArchiveLabel(__pmLogCtl *, pmLogLabel *) _PCP_HIDDEN;

 extern pmTimeval *__pmLogStartTime(__pmArchCtl *) _PCP_HIDDEN;

-extern void __pmLogSetTime(__pmContext *) _PCP_HIDDEN;

+extern int __pmLogSetTime(__pmContext *) _PCP_HIDDEN;

 extern void __pmLogResetInterp(__pmContext *) _PCP_HIDDEN;

 extern void __pmArchCtlFree(__pmArchCtl *) _PCP_HIDDEN;

 extern int __pmLogChangeArchive(__pmContext *, int) _PCP_HIDDEN;

diff --git a/src/libpcp/src/logutil.c b/src/libpcp/src/logutil.c

index 0ef76de25..2ea559bfe 100644

--- a/src/libpcp/src/logutil.c

+++ b/src/libpcp/src/logutil.c

@@ -1995,7 +1995,6 @@ __pmLogFetch(__pmContext *ctxp, int numpmid, pmID pmidlist[], pmResult **result)

     sts = __pmLogChangeVol(ctxp->c_archctl, ctxp->c_archctl->ac_vol);

     if (sts < 0)

 	goto func_return;

-    assert(ctxp->c_archctl->ac_mfp != NULL);

     __pmFseek(ctxp->c_archctl->ac_mfp, 

 	    (long)ctxp->c_archctl->ac_offset, SEEK_SET);

@@ -2010,7 +2009,9 @@ more:

 	     * no serial access, so need to make sure we are

 	     * starting in the correct place

 	     */

-	    __pmLogSetTime(ctxp);

+	    sts = __pmLogSetTime(ctxp);

+	    if (sts < 0)

+		goto func_return;

 	    ctxp->c_archctl->ac_offset = __pmFtell(ctxp->c_archctl->ac_mfp);

 	    ctxp->c_archctl->ac_vol = ctxp->c_archctl->ac_curvol;

 	    /*

@@ -2299,7 +2300,7 @@ VolSkip(__pmArchCtl *acp, int mode,  int j)

     return PM_ERR_EOL;

 }

-void

+int

 __pmLogSetTime(__pmContext *ctxp)

 {

     __pmArchCtl	*acp = ctxp->c_archctl;

@@ -2356,6 +2357,7 @@ __pmLogSetTime(__pmContext *ctxp)

     if (lcp->l_numti) {

 	/* we have a temporal index, use it! */

 	int		j = -1;

+	int		try;

 	int		toobig = 0;

 	int		match = 0;

 	int		vol;

@@ -2406,9 +2408,13 @@ __pmLogSetTime(__pmContext *ctxp)

 	acp->ac_serial = 1;

 	if (match) {

+	    try = j;

 	    j = VolSkip(acp, mode, j);

-	    if (j < 0)

-		return;

+	    if (j < 0) {

+		if (pmDebugOptions.log)

+		    fprintf(stderr, "__pmLogSetTime: VolSkip mode=%d vol=%d failed #1\n", mode, try);

+		return PM_ERR_LOGFILE;

+	    }

 	    __pmFseek(acp->ac_mfp, (long)lcp->l_ti[j].ti_log, SEEK_SET);

 	    if (mode == PM_MODE_BACK)

 		acp->ac_serial = 0;

@@ -2418,9 +2424,13 @@ __pmLogSetTime(__pmContext *ctxp)

 	    }

 	}

 	else if (j < 1) {

+	    try = 0;

 	    j = VolSkip(acp, PM_MODE_FORW, 0);

-	    if (j < 0)

-		return;

+	    if (j < 0) {

+		if (pmDebugOptions.log)

+		    fprintf(stderr, "__pmLogSetTime: VolSkip mode=%d vol=%d failed #2\n", PM_MODE_FORW, try);

+		return PM_ERR_LOGFILE;

+	    }

 	    __pmFseek(acp->ac_mfp, (long)lcp->l_ti[j].ti_log, SEEK_SET);

 	    if (pmDebugOptions.log) {

 		fprintf(stderr, " before start ti@");

@@ -2428,9 +2438,13 @@ __pmLogSetTime(__pmContext *ctxp)

 	    }

 	}

 	else if (j == numti) {

+	    try = numti-1;

 	    j = VolSkip(acp, PM_MODE_BACK, numti-1);

-	    if (j < 0)

-		return;

+	    if (j < 0) {

+		if (pmDebugOptions.log)

+		    fprintf(stderr, "__pmLogSetTime: VolSkip mode=%d vol=%d failed #3\n", PM_MODE_BACK, try);

+		return PM_ERR_LOGFILE;

+	    }

 	    __pmFseek(acp->ac_mfp, (long)lcp->l_ti[j].ti_log, SEEK_SET);

 	    if (mode == PM_MODE_BACK)

 		acp->ac_serial = 0;

@@ -2450,9 +2464,13 @@ __pmLogSetTime(__pmContext *ctxp)

 	    t_hi = __pmTimevalSub(&lcp->l_ti[j].ti_stamp, &ctxp->c_origin);

 	    t_lo = __pmTimevalSub(&ctxp->c_origin, &lcp->l_ti[j-1].ti_stamp);

 	    if (t_hi <= t_lo && !toobig) {

+		try = j;

 		j = VolSkip(acp, mode, j);

-		if (j < 0)

-		    return;

+		if (j < 0) {

+		    if (pmDebugOptions.log)

+			fprintf(stderr, "__pmLogSetTime: VolSkip mode=%d vol=%d failed #4\n", mode, try);

+		    return PM_ERR_LOGFILE;

+		}

 		__pmFseek(acp->ac_mfp, (long)lcp->l_ti[j].ti_log, SEEK_SET);

 		if (mode == PM_MODE_FORW)

 		    acp->ac_serial = 0;

@@ -2462,9 +2480,13 @@ __pmLogSetTime(__pmContext *ctxp)

 		}

 	    }

 	    else {

+		try = j-1;

 		j = VolSkip(acp, mode, j-1);

-		if (j < 0)

-		    return;

+		if (j < 0) {

+		    if (pmDebugOptions.log)

+			fprintf(stderr, "__pmLogSetTime: VolSkip mode=%d vol=%d failed #5\n", mode, try);

+		    return PM_ERR_LOGFILE;

+		}

 		__pmFseek(acp->ac_mfp, (long)lcp->l_ti[j].ti_log, SEEK_SET);

 		if (mode == PM_MODE_BACK)

 		    acp->ac_serial = 0;

@@ -2490,14 +2512,37 @@ __pmLogSetTime(__pmContext *ctxp)

     }

     else {

 	/* index either not available, or not useful */

+	int	j;

 	if (mode == PM_MODE_FORW) {

-	    __pmLogChangeVol(acp, lcp->l_minvol);

-	    assert(acp->ac_mfp != NULL);

+	    for (j = lcp->l_minvol; j <= lcp->l_maxvol; j++) {

+		if (__pmLogChangeVol(acp, j) >= 0)

+		    break;

+	    }

+	    if (j > lcp->l_maxvol) {

+		/* no volume found */

+		if (pmDebugOptions.log)

+		    fprintf(stderr, " index not useful, no volume between %d...%d\n",

+			    lcp->l_minvol, lcp->l_maxvol);

+		acp->ac_curvol = -1;

+		acp->ac_mfp = NULL;

+		return PM_ERR_LOGFILE;

+	    }

 	    __pmFseek(acp->ac_mfp, (long)(sizeof(__pmLogLabel) + 2*sizeof(int)), SEEK_SET);

 	}

 	else if (mode == PM_MODE_BACK) {

-	    __pmLogChangeVol(acp, lcp->l_maxvol);

-	    assert(acp->ac_mfp != NULL);

+	    for (j = lcp->l_maxvol; j >= lcp->l_minvol; j--) {

+		if (__pmLogChangeVol(acp, j) >= 0)

+		    break;

+	    }

+	    if (j < lcp->l_minvol) {

+		/* no volume found */

+		if (pmDebugOptions.log)

+		    fprintf(stderr, " index not useful, no volume between %d...%d\n",

+			    lcp->l_maxvol, lcp->l_minvol);

+		acp->ac_curvol = -1;

+		acp->ac_mfp = NULL;

+		return PM_ERR_LOGFILE;

+	    }

 	    __pmFseek(acp->ac_mfp, (long)0, SEEK_END);

 	}

@@ -2513,6 +2558,8 @@ __pmLogSetTime(__pmContext *ctxp)

     acp->ac_offset = __pmFtell(acp->ac_mfp);

     assert(acp->ac_offset >= 0);

     acp->ac_vol = acp->ac_curvol;

+

+    return 0;

 }

 /* Read the label of the current archive. */

@@ -3100,6 +3147,7 @@ LogChangeToPreviousArchive(__pmContext *ctxp)

     pmTimeval		save_origin;

     int			save_mode;

     int			sts;

+    int			j;

     /*

      * Check whether there is a previous archive to switch to.

@@ -3145,12 +3193,23 @@ LogChangeToPreviousArchive(__pmContext *ctxp)

     }

     /* Set up to scan backwards from the end of the archive. */

-    __pmLogChangeVol(acp, lcp->l_maxvol);

-    assert(acp->ac_mfp != NULL);

+    for (j = lcp->l_maxvol; j >= lcp->l_minvol; j--) {

+	if (__pmLogChangeVol(acp, j) >= 0)

+	    break;

+    }

+    if (j < lcp->l_minvol) {

+	/* no volume found */

+	if (pmDebugOptions.log)

+	    fprintf(stderr, "LogChangeToPreviousArchive: no volume between %d...%d\n",

+		    lcp->l_maxvol, lcp->l_minvol);

+	acp->ac_curvol = -1;

+	acp->ac_mfp = NULL;

+	return PM_ERR_LOGFILE;

+    }

     __pmFseek(acp->ac_mfp, (long)0, SEEK_END);

-    ctxp->c_archctl->ac_offset = __pmFtell(acp->ac_mfp);

-    assert(ctxp->c_archctl->ac_offset >= 0);

-    ctxp->c_archctl->ac_vol = ctxp->c_archctl->ac_curvol;

+    acp->ac_offset = __pmFtell(acp->ac_mfp);

+    assert(acp->ac_offset >= 0);

+    acp->ac_vol = acp->ac_curvol;

     /*

      * Check for temporal overlap here. Do this last in case the API client

commit 5e3b792d3d8ae60f2cebbd51c37b9b0722c3b26e

Author: Mark Goodwin <mgoodwin@redhat.com>

Date:   Tue Jul 6 20:09:28 2021 +1000

    libpcp_web: plug mem leak in redisMapInsert during daily log-rolling

    When pmlogger_daily processes daily archives, the resulting

    merged archive(s) are discovered and processed by pmproxy

    (if the discovery module is enabled). Since the metadata and

    logvol data in each merged archive is likely to have already

    been previously processed (but discovery doesn't know this),

    we see a lot of dict updates for existing keys and values that

    are already mapped.

    Static analysis by Coverity (CID323605 Resource Leak) shows

    when redisMapInsert calls dictAdd for an existing key, the

    new value field is assigned but the old value is not free'd,

    and so it leaks.

    Related: RHBZ1975069 and https://github.com/performancecopilot/pcp/issues/1318

diff --git a/src/libpcp_web/src/maps.c b/src/libpcp_web/src/maps.c

index 013ef02d3..ce20476c9 100644

--- a/src/libpcp_web/src/maps.c

+++ b/src/libpcp_web/src/maps.c

@@ -160,6 +160,12 @@ redisMapLookup(redisMap *map, sds key)

 void

 redisMapInsert(redisMap *map, sds key, sds value)

 {

+    redisMapEntry *entry = redisMapLookup(map, key);

+

+    if (entry) {

+	/* fix for Coverity CID323605 Resource Leak */

+	dictDelete(map, key);

+    }

     dictAdd(map, key, value);

 }

commit 2a00a90b0bc3aecb8465fd32aef1ddbe745b2c91

Author: Mark Goodwin <mgoodwin@redhat.com>

Date:   Tue Jul 6 20:43:01 2021 +1000

    libpcp_web/discovery: improve lock handling and scalability

    Rework the global log-rolling lock detection with finer grain

    (per-pmlogger directory) detection, and break early in

    process_meta() and process_logvol() if a lock file is found

    in the same directory as a monitored archive. This is much

    more scalable since archive directories that are not locked

    can continue to be processed and ingested whilst log-rolling

    progresses elsewhere. Also uses much less CPU time since we

    don't need a traversal of all monitored archives looking for

    locks on every fs change event.

    Also improve process_logvol/meta handling for archives that

    are deleted whilst being processed by the discovery module.

    In conjunction with Kenj's changes in libpcp - stop processing

    metadata and logvols if pmFetchArchive returns -ENOENT .. the

    archive has been deleted so there is no point further ingesting

    it's data.

    Related: RHBZ1975069

    Related: https://github.com/performancecopilot/pcp/issues/1338

diff --git a/src/libpcp_web/src/discover.c b/src/libpcp_web/src/discover.c

index 991055ce5..964813f66 100644

--- a/src/libpcp_web/src/discover.c

+++ b/src/libpcp_web/src/discover.c

@@ -33,9 +33,6 @@ static char *pmDiscoverFlagsStr(pmDiscover *);

 #define PM_DISCOVER_HASHTAB_SIZE 32

 static pmDiscover *discover_hashtable[PM_DISCOVER_HASHTAB_SIZE];

-/* pmlogger_daily log-roll lock count */

-static int logrolling = 0;

-

 /* number of archives or directories currently being monitored */

 static int n_monitored = 0;

@@ -426,28 +423,6 @@ is_deleted(pmDiscover *p, struct stat *sbuf)

     return ret;

 }

-static int

-check_for_locks()

-{

-    int			i;

-    pmDiscover		*p;

-    char                sep = pmPathSeparator();

-    char                path[MAXNAMELEN];

-

-    for (i=0; i < PM_DISCOVER_HASHTAB_SIZE; i++) {

-    	for (p = discover_hashtable[i]; p; p = p->next) {

-	    if (p->flags & PM_DISCOVER_FLAGS_DIRECTORY) {

-		pmsprintf(path, sizeof(path), "%s%c%s", p->context.name, sep, "lock");

-		if (access(path, F_OK) == 0)

-		    return 1;

-	    }

-	}

-    }

-

-    /* no locks */

-    return 0;

-}

-