Fix global (DB_PRIVATE) lock code: fix recursion counter, retry

failed lock operations for up to 3 minutes.

--- ./lib/backend/db3.c.orig	2017-01-19 14:59:01.432807649 +0000

+++ ./lib/backend/db3.c	2017-01-19 15:13:18.034716068 +0000

@@ -33,6 +33,8 @@ struct dbiCursor_s {

 static struct dbiConfig_s staticdbicfg;

 static struct dbConfig_s staticcfg;

+static int _lockdbfd = 0;

+

 /** \ingroup dbi

  */

 static const struct poptOption rdbOptions[] = {

@@ -744,6 +746,8 @@ static int db3_dbiClose(dbiIndex dbi, un

 	rpmlog(RPMLOG_DEBUG, "closed   db index       %s/%s\n",

 		dbhome, dbi->dbi_file);

+	if (dbi->cfg.dbi_lockdbfd && !(dbi->dbi_flags & DBI_VERIFYONLY) && _lockdbfd)

+	    _lockdbfd--;

     }

     db_fini(rdb, dbhome ? dbhome : "");

@@ -783,6 +787,7 @@ static int dbiFlock(dbiIndex dbi, int mo

 	rc = 1;

     } else {

 	const char *dbhome = rpmdbHome(dbi->dbi_rpmdb);

+	int tries;

 	struct flock l;

 	memset(&l, 0, sizeof(l));

 	l.l_whence = 0;

@@ -792,20 +797,38 @@ static int dbiFlock(dbiIndex dbi, int mo

 		    ? F_RDLCK : F_WRLCK;

 	l.l_pid = 0;

-	rc = fcntl(fdno, F_SETLK, (void *) &l);

-	if (rc) {

-	    uint32_t eflags = db_envflags(db);

-	    /* Warning iff using non-private CDB locking. */

-	    rc = (((eflags & DB_INIT_CDB) && !(eflags & DB_PRIVATE)) ? 0 : 1);

-	    rpmlog( (rc ? RPMLOG_ERR : RPMLOG_WARNING),

-		    _("cannot get %s lock on %s/%s\n"),

-		    ((mode & O_ACCMODE) == O_RDONLY)

-			    ? _("shared") : _("exclusive"),

-		    dbhome, dbi->dbi_file);

-	} else {

-	    rpmlog(RPMLOG_DEBUG,

-		    "locked   db index       %s/%s\n",

-		    dbhome, dbi->dbi_file);

+	for (tries = 0; ; tries++) {

+	    rc = fcntl(fdno, F_SETLK, (void *) &l);

+	    if (rc) {

+		uint32_t eflags = db_envflags(db);

+		/* Warning iff using non-private CDB locking. */

+		rc = (((eflags & DB_INIT_CDB) && !(eflags & DB_PRIVATE)) ? 0 : 1);

+		if (errno == EAGAIN && rc) {

+		    struct timespec ts;

+		    if (tries == 0)

+			rpmlog(RPMLOG_WARNING,

+				_("waiting for %s lock on %s/%s\n"),

+				((mode & O_ACCMODE) == O_RDONLY)

+					? _("shared") : _("exclusive"),

+				dbhome, dbi->dbi_file);

+		    ts.tv_sec = (time_t)0;

+		    ts.tv_nsec = 100000000;	/* .1 seconds */

+		    if (tries < 10*60*3) {	/* 3 minutes */

+			nanosleep(&ts, (struct timespec *)0);

+			continue;

+		    }

+		}

+		rpmlog( (rc ? RPMLOG_ERR : RPMLOG_WARNING),

+			_("cannot get %s lock on %s/%s\n"),

+			((mode & O_ACCMODE) == O_RDONLY)

+				? _("shared") : _("exclusive"),

+			dbhome, dbi->dbi_file);

+	    } else {

+		rpmlog(RPMLOG_DEBUG,

+			"locked   db index       %s/%s\n",

+			dbhome, dbi->dbi_file);

+	    }

+	    break;

 	}

     }

     return rc;

@@ -822,7 +845,6 @@ static int db3_dbiOpen(rpmdb rdb, rpmDbi

     DB * db = NULL;

     DBTYPE dbtype = DB_UNKNOWN;

     uint32_t oflags;

-    static int _lockdbfd = 0;

     if (dbip)

 	*dbip = NULL;

@@ -902,6 +924,8 @@ static int db3_dbiOpen(rpmdb rdb, rpmDbi

 	dbi->dbi_flags |= DBI_CREATED;

     if (oflags & DB_RDONLY)

 	dbi->dbi_flags |= DBI_RDONLY;

+    if (verifyonly)

+	dbi->dbi_flags |= DBI_VERIFYONLY;

     if (!verifyonly && rc == 0 && dbi->cfg.dbi_lockdbfd && _lockdbfd++ == 0) {

 	rc = dbiFlock(dbi, rdb->db_mode);

--- ./lib/backend/dbi.h.orig	2017-01-19 15:12:26.833899257 +0000

+++ ./lib/backend/dbi.h	2017-01-19 15:05:43.958347554 +0000

@@ -83,6 +83,7 @@ enum dbiFlags_e {

     DBI_NONE		= 0,

     DBI_CREATED		= (1 << 0),

     DBI_RDONLY		= (1 << 1),

+    DBI_VERIFYONLY	= (1 << 2),

 };

 enum dbcFlags_e {