X-Git-Url: http://git.ipfire.org/?p=thirdparty%2Fmdadm.git;a=blobdiff_plain;f=mapfile.c;h=8d7acb3cc389ca0ce49c1dabb99bfe2782875993;hp=955a1f98a243c1844b22a65d50909b42c9708c30;hb=b06815989179e0f153e44e4336290e655edce9a1;hpb=492350045c7e40741069caa7d017209439db665b

diff --git a/mapfile.c b/mapfile.c
index 955a1f98..8d7acb3c 100644
--- a/mapfile.c
+++ b/mapfile.c
@@ -1,8 +1,8 @@
 /*
- * mapfile - manage /var/run/mdadm.map. Part of:
+ * mapfile - keep track of uuid <-> array mapping. Part of:
  * mdadm - manage Linux "md" devices aka RAID arrays.
  *
- * Copyright (C) 2006 Neil Brown <neilb@suse.de>
+ * Copyright (C) 2006-2010 Neil Brown <neilb@suse.de>
  *
  *
  *    This program is free software; you can redistribute it and/or modify
@@ -28,8 +28,8 @@
  *           Australia
  */
 
-/* /var/run/mdadm.map is used to track arrays being created in --incremental
- * more.  It particularly allows lookup from UUID to array device, but
+/* The mapfile is used to track arrays being created in --incremental
+ * mode.  It particularly allows lookup from UUID to array device, but
  * also allows the array device name to be easily found.
  *
  * The map file is line based with space separated fields.  The fields are:
@@ -38,64 +38,139 @@
  *  UUID       -  uuid of the array
  *  path       -  path where device created: /dev/md/home
  *
+ * The best place for the mapfile is /run/mdadm/map.  Distros and users
+ * which have not switched to /run yet can choose a different location
+ * at compile time via MAP_DIR and MAP_FILE.
  */
+#include	"mdadm.h"
+#include	<sys/file.h>
+#include	<ctype.h>
 
+#define MAP_READ 0
+#define MAP_NEW 1
+#define MAP_LOCK 2
+#define MAP_DIRNAME 3
 
-#include "mdadm.h"
+char *mapname[4] = {
+	MAP_DIR "/" MAP_FILE,
+	MAP_DIR "/" MAP_FILE ".new",
+	MAP_DIR "/" MAP_FILE ".lock",
+	MAP_DIR
+};
 
+int mapmode[3] = { O_RDONLY, O_RDWR|O_CREAT, O_RDWR|O_CREAT|O_TRUNC };
+char *mapsmode[3] = { "r", "w", "w"};
+
+FILE *open_map(int modenum)
+{
+	int fd;
+	if ((mapmode[modenum] & O_CREAT))
+		/* Attempt to create directory, don't worry about
+		 * failure.
+		 */
+		(void)mkdir(mapname[MAP_DIRNAME], 0755);
+	fd = open(mapname[modenum], mapmode[modenum], 0600);
+	if (fd >= 0)
+		return fdopen(fd, mapsmode[modenum]);
+	return NULL;
+}
 
 int map_write(struct map_ent *mel)
 {
 	FILE *f;
 	int err;
-	int subdir = 1;
 
-	f = fopen("/var/run/mdadm/map.new", "w");
-	if (!f) {
-		f = fopen("/var/run/mdadm.map.new", "w");
-		subdir = 1;
-	}
+	f = open_map(MAP_NEW);
+
 	if (!f)
 		return 0;
-	while (mel) {
-		if (mel->devnum < 0)
-			fprintf(f, "mdp%d ", -1-mel->devnum);
-		else
-			fprintf(f, "md%d ", mel->devnum);
+	for (; mel; mel = mel->next) {
+		if (mel->bad)
+			continue;
+		fprintf(f, "%s ", mel->devnm);
 		fprintf(f, "%s ", mel->metadata);
 		fprintf(f, "%08x:%08x:%08x:%08x ", mel->uuid[0],
 			mel->uuid[1], mel->uuid[2], mel->uuid[3]);
-		fprintf(f, "%s\n", mel->path);
-		mel = mel->next;
+		fprintf(f, "%s\n", mel->path?:"");
 	}
 	fflush(f);
 	err = ferror(f);
 	fclose(f);
 	if (err) {
-		if (subdir)
-			unlink("/var/run/mdadm/map.new");
-		else
-			unlink("/var/run/mdadm.map.new");
+		unlink(mapname[1]);
 		return 0;
 	}
-	if (subdir)
-		return rename("/var/run/mdadm/map.new",
-			      "/var/run/mdadm/map") == 0;
-	else
-		return rename("/var/run/mdadm.map.new",
-			      "/var/run/mdadm.map") == 0;
+	return rename(mapname[1],
+		      mapname[0]) == 0;
+}
+
+static FILE *lf = NULL;
+int map_lock(struct map_ent **melp)
+{
+	while (lf == NULL) {
+		struct stat buf;
+		lf = open_map(MAP_LOCK);
+		if (lf == NULL)
+			return -1;
+		if (flock(fileno(lf), LOCK_EX) != 0) {
+			fclose(lf);
+			lf = NULL;
+			return -1;
+		}
+		if (fstat(fileno(lf), &buf) != 0 ||
+		    buf.st_nlink == 0) {
+			/* The owner of the lock unlinked it,
+			 * so we have a lock on a stale file,
+			 * try again
+			 */
+			fclose(lf);
+			lf = NULL;
+		}
+	}
+	if (*melp)
+		map_free(*melp);
+	map_read(melp);
+	return 0;
+}
+
+void map_unlock(struct map_ent **melp)
+{
+	if (lf) {
+		/* must unlink before closing the file,
+		 * as only the owner of the lock may
+		 * unlink the file
+		 */
+		unlink(mapname[2]);
+		fclose(lf);
+	}
+	if (*melp)
+		map_free(*melp);
+	lf = NULL;
+}
+
+void map_fork(void)
+{
+	/* We are forking, so must close the lock file.
+	 * Don't risk flushing anything though.
+	 */
+	if (lf) {
+		close(fileno(lf));
+		fclose(lf);
+		lf = NULL;
+	}
 }
 
 void map_add(struct map_ent **melp,
-	    int devnum, char *metadata, int uuid[4], char *path)
+	     char * devnm, char *metadata, int uuid[4], char *path)
 {
-	struct map_ent *me = malloc(sizeof(*me));
+	struct map_ent *me = xmalloc(sizeof(*me));
 
-	me->devnum = devnum;
+	strcpy(me->devnm, devnm);
 	strcpy(me->metadata, metadata);
 	memcpy(me->uuid, uuid, 16);
-	me->path = strdup(path);
+	me->path = path ? xstrdup(path) : NULL;
 	me->next = *melp;
+	me->bad = 0;
 	*melp = me;
 }
 
@@ -103,28 +178,27 @@ void map_read(struct map_ent **melp)
 {
 	FILE *f;
 	char buf[8192];
-	char path[200];
-	int devnum, uuid[4];
+	char path[201];
+	int uuid[4];
+	char devnm[32];
 	char metadata[30];
-	char nam[4];
 
 	*melp = NULL;
 
-	f = fopen("/var/run/mdadm/map", "r");
-	if (!f)
-		f = fopen("/var/run/mdadm.map", "r");
+	f = open_map(MAP_READ);
+	if (!f) {
+		RebuildMap();
+		f = open_map(MAP_READ);
+	}
 	if (!f)
 		return;
 
 	while (fgets(buf, sizeof(buf), f)) {
-		if (sscanf(buf, " %3[mdp]%d %s %x:%x:%x:%x %200s",
-			   nam, &devnum, metadata, uuid, uuid+1,
-			   uuid+2, uuid+3, path) == 8) {
-			if (strncmp(nam, "md", 2) != 0)
-				continue;
-			if (nam[2] == 'p')
-				devnum = -1 - devnum;
-			map_add(melp, devnum, metadata, uuid, path);
+		path[0] = 0;
+		if (sscanf(buf, " %s %s %x:%x:%x:%x %200s",
+			   devnm, metadata, uuid, uuid+1,
+			   uuid+2, uuid+3, path) >= 7) {
+			map_add(melp, devnm, metadata, uuid, path);
 		}
 	}
 	fclose(f);
@@ -140,7 +214,7 @@ void map_free(struct map_ent *map)
 	}
 }
 
-int map_update(struct map_ent **mpp, int devnum, char *metadata,
+int map_update(struct map_ent **mpp, char *devnm, char *metadata,
 	       int *uuid, char *path)
 {
 	struct map_ent *map, *mp;
@@ -152,22 +226,24 @@ int map_update(struct map_ent **mpp, int devnum, char *metadata,
 		map_read(&map);
 
 	for (mp = map ; mp ; mp=mp->next)
-		if (mp->devnum == devnum) {
+		if (strcmp(mp->devnm, devnm) == 0) {
 			strcpy(mp->metadata, metadata);
 			memcpy(mp->uuid, uuid, 16);
 			free(mp->path);
-			mp->path = strdup(path);
+			mp->path = path ? xstrdup(path) : NULL;
+			mp->bad = 0;
 			break;
 		}
 	if (!mp)
-		map_add(&map, devnum, metadata, uuid, path);
-	*mpp = NULL;
+		map_add(&map, devnm, metadata, uuid, path);
+	if (mpp)
+		*mpp = NULL;
 	rv = map_write(map);
 	map_free(map);
 	return rv;
 }
 
-void map_delete(struct map_ent **mapp, int devnum)
+void map_delete(struct map_ent **mapp, char *devnm)
 {
 	struct map_ent *mp;
 
@@ -175,7 +251,7 @@ void map_delete(struct map_ent **mapp, int devnum)
 		map_read(mapp);
 
 	for (mp = *mapp; mp; mp = *mapp) {
-		if (mp->devnum == devnum) {
+		if (strcmp(mp->devnm, devnm) == 0) {
 			*mapp = mp->next;
 			free(mp->path);
 			free(mp);
@@ -184,15 +260,252 @@ void map_delete(struct map_ent **mapp, int devnum)
 	}
 }
 
+void map_remove(struct map_ent **mapp, char *devnm)
+{
+	if (devnm[0] == 0)
+		return;
+
+	map_delete(mapp, devnm);
+	map_write(*mapp);
+	map_free(*mapp);
+	*mapp = NULL;
+}
+
 struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4])
 {
 	struct map_ent *mp;
 	if (!*map)
 		map_read(map);
 
-	for (mp = *map ; mp ; mp = mp->next)
-		if (memcmp(uuid, mp->uuid, 16) == 0)
-			return mp;
+	for (mp = *map ; mp ; mp = mp->next) {
+		if (memcmp(uuid, mp->uuid, 16) != 0)
+			continue;
+		if (!mddev_busy(mp->devnm)) {
+			mp->bad = 1;
+			continue;
+		}
+		return mp;
+	}
 	return NULL;
+}
+
+struct map_ent *map_by_devnm(struct map_ent **map, char *devnm)
+{
+	struct map_ent *mp;
+	if (!*map)
+		map_read(map);
 
+	for (mp = *map ; mp ; mp = mp->next) {
+		if (strcmp(mp->devnm, devnm) != 0)
+			continue;
+		if (!mddev_busy(mp->devnm)) {
+			mp->bad = 1;
+			continue;
+		}
+		return mp;
+	}
+	return NULL;
+}
+
+struct map_ent *map_by_name(struct map_ent **map, char *name)
+{
+	struct map_ent *mp;
+	if (!*map)
+		map_read(map);
+
+	for (mp = *map ; mp ; mp = mp->next) {
+		if (!mp->path)
+			continue;
+		if (strncmp(mp->path, "/dev/md/", 8) != 0)
+			continue;
+		if (strcmp(mp->path+8, name) != 0)
+			continue;
+		if (!mddev_busy(mp->devnm)) {
+			mp->bad = 1;
+			continue;
+		}
+		return mp;
+	}
+	return NULL;
+}
+
+/* sets the proper subarray and container_dev according to the metadata
+ * version super_by_fd does this automatically, this routine is meant as
+ * a supplement for guess_super()
+ */
+static char *get_member_info(struct mdstat_ent *ent)
+{
+
+	if (ent->metadata_version == NULL ||
+	    strncmp(ent->metadata_version, "external:", 9) != 0)
+		return NULL;
+
+	if (is_subarray(&ent->metadata_version[9])) {
+		char *subarray;
+
+		subarray = strrchr(ent->metadata_version, '/');
+		return subarray + 1;
+	}
+	return NULL;
+}
+
+void RebuildMap(void)
+{
+	struct mdstat_ent *mdstat = mdstat_read(0, 0);
+	struct mdstat_ent *md;
+	struct map_ent *map = NULL;
+	int require_homehost;
+	char sys_hostname[256];
+	char *homehost = conf_get_homehost(&require_homehost);
+
+	if (homehost == NULL || strcmp(homehost, "<system>")==0) {
+		if (gethostname(sys_hostname, sizeof(sys_hostname)) == 0) {
+			sys_hostname[sizeof(sys_hostname)-1] = 0;
+			homehost = sys_hostname;
+		}
+	}
+
+	for (md = mdstat ; md ; md = md->next) {
+		struct mdinfo *sra = sysfs_read(-1, md->devnm, GET_DEVS);
+		struct mdinfo *sd;
+
+		if (!sra)
+			continue;
+
+		for (sd = sra->devs ; sd ; sd = sd->next) {
+			char namebuf[100];
+			char dn[30];
+			int dfd;
+			int ok;
+			dev_t devid;
+			struct supertype *st;
+			char *subarray = NULL;
+			char *path;
+			struct mdinfo *info;
+
+			sprintf(dn, "%d:%d", sd->disk.major, sd->disk.minor);
+			dfd = dev_open(dn, O_RDONLY);
+			if (dfd < 0)
+				continue;
+			st = guess_super(dfd);
+			if ( st == NULL)
+				ok = -1;
+			else {
+				subarray = get_member_info(md);
+				ok = st->ss->load_super(st, dfd, NULL);
+			}
+			close(dfd);
+			if (ok != 0)
+				continue;
+			if (subarray)
+				info = st->ss->container_content(st, subarray);
+			else {
+				info = xmalloc(sizeof(*info));
+				st->ss->getinfo_super(st, info, NULL);
+			}
+			if (!info)
+				continue;
+
+			devid = devnm2devid(md->devnm);
+			path = map_dev(major(devid), minor(devid), 0);
+			if (path == NULL ||
+			    strncmp(path, "/dev/md/", 8) != 0) {
+				/* We would really like a name that provides
+				 * an MD_DEVNAME for udev.
+				 * The name needs to be unique both in /dev/md/
+				 * and in this mapfile.
+				 * It needs to match what -I or -As would come
+				 * up with.
+				 * That means:
+				 *   Check if array is in mdadm.conf
+				 *        - if so use that.
+				 *   determine trustworthy from homehost etc
+				 *   find a unique name based on metadata name.
+				 *
+				 */
+				struct mddev_ident *match = conf_match(st, info,
+								       NULL, 0,
+								       NULL);
+				struct stat stb;
+				if (match && match->devname && match->devname[0] == '/') {
+					path = match->devname;
+					if (path[0] != '/') {
+						strcpy(namebuf, "/dev/md/");
+						strcat(namebuf, path);
+						path = namebuf;
+					}
+				} else {
+					int unum = 0;
+					char *sep = "_";
+					const char *name;
+					int conflict = 1;
+					if ((homehost == NULL ||
+					     st->ss->match_home(st, homehost) != 1) &&
+					    st->ss->match_home(st, "any") != 1 &&
+					    (require_homehost ||
+					     !conf_name_is_free(info->name)))
+						/* require a numeric suffix */
+						unum = 0;
+					else
+						/* allow name to be used as-is if no conflict */
+						unum = -1;
+					name = info->name;
+					if (!*name) {
+						name = st->ss->name;
+						if (!isdigit(name[strlen(name)-1]) &&
+						    unum == -1) {
+							unum = 0;
+							sep = "";
+						}
+					}
+					if (strchr(name, ':')) {
+						/* Probably a uniquifying
+						 * hostname prefix.  Allow
+						 * without a suffix, and strip
+						 * hostname if it is us.
+						 */
+						if (homehost && unum == -1 &&
+						    strncmp(name, homehost,
+							    strlen(homehost)) == 0 &&
+						    name[strlen(homehost)] == ':')
+							name += strlen(homehost)+1;
+						unum = -1;
+					}
+
+					while (conflict) {
+						if (unum >= 0)
+							sprintf(namebuf, "/dev/md/%s%s%d",
+								name, sep, unum);
+						else
+							sprintf(namebuf, "/dev/md/%s",
+								name);
+						unum++;
+						if (lstat(namebuf, &stb) != 0 &&
+						    (map == NULL ||
+						     !map_by_name(&map, namebuf+8)))
+							conflict = 0;
+					}
+					path = namebuf;
+				}
+			}
+			map_add(&map, md->devnm,
+				info->text_version,
+				info->uuid, path);
+			st->ss->free_super(st);
+			free(info);
+			break;
+		}
+		sysfs_free(sra);
+	}
+	/* Only trigger a change if we wrote a new map file */
+	if (map_write(map))
+		for (md = mdstat ; md ; md = md->next) {
+			struct mdinfo *sra = sysfs_read(-1, md->devnm,
+							GET_VERSION);
+			if (sra)
+				sysfs_uevent(sra, "change");
+			sysfs_free(sra);
+		}
+	map_free(map);
+	free_mdstat(mdstat);
 }