- Fix racy locking of mapfile (bz616596)

mdadm-3.1.2-lock.patch

@@ -0,0 +1,65 @@
+--- mdadm-3.1.2/Incremental.c.lock	2010-07-20 17:21:41.879217630 -0400
++++ mdadm-3.1.2/Incremental.c	2010-07-20 17:21:41.916342431 -0400
+@@ -285,7 +285,9 @@ int Incremental(char *devname, int verbo
+ 
+ 	/* 4/ Check if array exists.
+ 	 */
+-	map_lock(&map);
++	if (map_lock(&map))
++		fprintf(stderr, Name ": failed to get exclusive lock on "
++			"mapfile\n");
+ 	mp = map_by_uuid(&map, info.uuid);
+ 	if (mp)
+ 		mdfd = open_dev(mp->devnum);
+@@ -769,7 +771,9 @@ int Incremental_container(struct superty
+ 	struct mdinfo *ra;
+ 	struct map_ent *map = NULL;
+ 
+-	map_lock(&map);
++	if (map_lock(&map))
++		fprintf(stderr, Name ": failed to get exclusive lock on "
++			"mapfile\n");
+ 
+ 	for (ra = list ; ra ; ra = ra->next) {
+ 		int mdfd;
+--- mdadm-3.1.2/mapfile.c.lock	2010-07-20 17:21:41.687217302 -0400
++++ mdadm-3.1.2/mapfile.c	2010-07-20 17:23:23.038096346 -0400
+@@ -58,7 +58,7 @@ char *mapname[2][3] = {
+ };
+ char *mapdir[2] = { MAP_DIR, NULL };
+ 
+-int mapmode[3] = { O_RDONLY, O_RDWR|O_CREAT, O_RDWR|O_CREAT|O_TRUNC };
++int mapmode[3] = { O_RDONLY, O_RDWR|O_CREAT, O_RDWR|O_CREAT|O_EXCL };
+ char *mapsmode[3] = { "r", "w", "w"};
+ 
+ FILE *open_map(int modenum, int *choice)
+@@ -120,14 +120,11 @@ static int lwhich = 0;
+ int map_lock(struct map_ent **melp)
+ {
+ 	if (lf == NULL) {
+-		lf = open_map(2, &lwhich);
++		do {
++			lf = open_map(2, &lwhich);
++		} while (lf == NULL && errno == EEXIST);
+ 		if (lf == NULL)
+ 			return -1;
+-		if (flock(fileno(lf), LOCK_EX) != 0) {
+-			fclose(lf);
+-			lf = NULL;
+-			return -1;
+-		}
+ 	}
+ 	if (*melp)
+ 		map_free(*melp);
+@@ -137,10 +134,7 @@ int map_lock(struct map_ent **melp)
+ 
+ void map_unlock(struct map_ent **melp)
+ {
+-	if (lf) {
+-		flock(fileno(lf), LOCK_UN);
+-		fclose(lf);
+-	}
++	fclose(lf);
+ 	unlink(mapname[lwhich][2]);
+ 	lf = NULL;
+ }

mdadm.spec

@@ -1,13 +1,14 @@
 Summary:     The mdadm program controls Linux md devices (software RAID arrays)
 Name:        mdadm
 Version:     3.1.3
-Release:     0.git07202010.1%{?dist}
+Release:     0.git07202010.2%{?dist}
 Source:      http://www.kernel.org/pub/linux/utils/raid/mdadm/mdadm-%{version}-git07202010.tar.bz2
 Source1:     mdmonitor.init
 Source2:     raid-check
 Source3:     mdadm.rules
 Source4:     mdadm-raid-check-sysconfig
 Patch0:      mdadm-3.1.3-read.patch
+PAtch1:      mdadm-3.1.2-lock.patch
 Patch20:     mdadm-2.5.2-static.patch
 URL:         http://www.kernel.org/pub/linux/utils/raid/mdadm/
 License:     GPLv2+
@@ -30,6 +31,7 @@ file can be used to help with some common tasks.
 %prep
 %setup -q -n mdadm-3.1.3-git07202010
 %patch0 -p1 -b .read
+%patch1 -p1 -b .lock
 %patch20 -p1 -b .static
 
 %build
@@ -75,6 +77,9 @@ fi
 %attr(0700,root,root) %dir /var/run/mdadm
 
 %changelog
+* Tue Jul 20 2010 Doug Ledford <dledford@redhat.com> - 3.1.3-0.git07202010.2
+- Fix racy locking of mapfile (bz616596)
+
 * Tue Jul 20 2010 Doug Ledford <dledford@redhat.com> - 3.1.3-0.git07202010.1
 - Update to latest git repo (3.1.2 plus pending changes, fixes bz602457)
 - Add in 64-md-raid.rules to compensate for it no longer being in udev