mdopen: Introduce new rules for creating device name.

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Assemble.c

@@ -142,7 +142,8 @@ int Assemble(struct supertype *st, char *mddev,
 	mdu_array_info_t tmp_inf;
 	char *avail;
 	int nextspare = 0;
-	int uuid_for_name = 0;
+	char *name;
+	int trustworthy;
 
 	memset(&info, 0, sizeof(info));
 
@@ -331,29 +332,6 @@ int Assemble(struct supertype *st, char *mddev,
 		if (auto_assem) {
 			if (tst == NULL || tst->sb == NULL)
 				continue;
-			switch(tst->ss->match_home(tst, homehost))
-			{
-			case 1: /* happy with match. */
-				break;
-			case -1: /* cannot match */
-				uuid_for_name = 1;
-				break;
-			case 0: /* Doesn't match */
-				if (update)
-					/* We are changing the name*/
-					break;
-				if ((inargv && verbose >= 0) || verbose > 0)
-					fprintf(stderr, Name ": %s is not built for "
-						"host %s - using UUID for "
-						"device name.\n",
-						devname, homehost);
-				
-				/* Auto-assemble, and this is not a usable host */
-				/* if update != NULL, we are updating the host
-				 * name... */
-				uuid_for_name = 1;
-				break;
-			}
 		}
 		/* If we are this far, then we are nearly commited to this device.
 		 * If the super_block doesn't exist, or doesn't match others,
@@ -425,36 +403,32 @@ int Assemble(struct supertype *st, char *mddev,
 	if (!st || !st->sb)
 		return 2;
 
-	/* Now need to open array the device.
-	 * We create a name '/dev/md/XXX' based on the info in the
-	 * superblock, and call create_mddev on that
-	 */
+	/* Now need to open array the device.  Use create_mddev */
+	st->ss->getinfo_super(st, &info);
 
-	if (mddev == NULL) {
-		char nbuf[64];
-		char *c;
-		int rc;
-
-		st->ss->getinfo_super(st, &info);
-		if (uuid_for_name)
-			c = fname_from_uuid(st, &info, nbuf, '-');
-		else {
-			c = strchr(info.name, ':');
-			if (c) c++; else c= info.name;
-		}
-		if (isdigit(*c) && ((ident->autof & 7)==4 || (ident->autof&7)==6))
-			/* /dev/md/d0 style for partitionable */
-			rc = asprintf(&mddev, "/dev/md/d%s", c);
+	trustworthy = FOREIGN;
+	switch (st->ss->match_home(st, homehost)) {
+	case 0:
+		trustworthy = FOREIGN;
+		name = info.name;
+		break;
+	case 1:
+		trustworthy = LOCAL;
+		name = strchr(info.name, ':');
+		if (name)
+			name++;
 		else
-			rc = asprintf(&mddev, "/dev/md/%s", c);
-		if (rc < 0) {
-			st->ss->free_super(st);
-			free(devices);
-			mddev = NULL;
-			goto try_again;
-		}
+			name = info.name;
+		break;
+	case -1:
+		if (info.name[0] == 0 && info.array.level == LEVEL_CONTAINER) {
+			name = info.text_version;
+			trustworthy = METADATA;
+		} else
+			trustworthy = FOREIGN;
+		break;
 	}
-	mdfd = create_mddev(mddev, ident->autof);
+	mdfd = create_mddev(mddev, name, ident->autof, trustworthy, NULL);
 	if (mdfd < 0) {
 		st->ss->free_super(st);
 		free(devices);

Build.c

@@ -113,8 +113,8 @@ int Build(char *mddev, int chunk, int level, int layout,
 			break;
 		}
 
-	/* We need to create the device */
-	mdfd = create_mddev(mddev, autof);
+	/* We need to create the device.  It can have no name. */
+	mdfd = create_mddev(mddev, NULL, autof, LOCAL, NULL);
 	if (mdfd < 0)
 		return 1;
 

Create.c

@@ -421,7 +421,7 @@ int Create(struct supertype *st, char *mddev,
 	}
 
 	/* We need to create the device */
-	mdfd = create_mddev(mddev, autof);
+	mdfd = create_mddev(mddev, name, autof, LOCAL, NULL);
 	if (mdfd < 0)
 		return 1;
 
@@ -514,6 +514,7 @@ int Create(struct supertype *st, char *mddev,
 		 *  /dev/md/home -> home
 		 *  /dev/mdhome -> home
 		 */
+		/* FIXME compare this with rules in create_mddev */
 		name = strrchr(mddev, '/');
 		if (name) {
 			name++;

mdadm.h

@@ -801,7 +801,12 @@ extern char *get_md_name(int dev);
 
 extern char DefaultConfFile[];
 
-extern int create_mddev(char *dev, int autof);
+extern int create_mddev(char *dev, char *name, int autof, int trustworthy,
+			char *chosen);
+/* values for 'trustworthy' */
+#define	LOCAL	1
+#define	FOREIGN	2
+#define	METADATA 3
 extern int open_mddev(char *dev, int report_errors);
 extern int create_mddev_devnum(char *devname, int devnum, char *name,
 			     char *chosen_name, int parts);

mdassemble.c

@@ -69,7 +69,8 @@ int open_mddev(char *dev, int report_errors/*unused*/)
 	}
 	return mdfd;
 }
-int create_mddev(char *dev, int autof/*unused*/)
+int create_mddev(char *dev, char *name, int autof/*unused*/, int trustworthy,
+		 char *chosen)
 {
 	return open_mddev(dev, 0);
 }

mdopen.c

@@ -98,24 +98,54 @@ void make_parts(char *dev, int cnt, int symlinks)
 
 
 /*
- * Open a given md device, and check that it really is one.
- * If 'autof' is given, then we need to create, or recreate, the md device.
- * If the name already exists, and is not a block device, we fail.
- * If it exists and is not an md device, is not the right type (partitioned or not),
- * or is currently in-use, we remove the device, but remember the owner and mode.
- * If it now doesn't exist, we find a new md array and create the device.
- * Default ownership/mode comes from config file.
+ * We need a new md device to assemble/build/create an array.
+ * 'dev' is a name given us by the user (command line or mdadm.conf)
+ * It might start with /dev or /dev/md any might end with a digit
+ * string.
+ * If it starts with just /dev, it must be /dev/mdX or /dev/md_dX
+ * If it ends with a digit string, then it must be as above, or
+ * 'trustworthy' must be 'METADATA' and the 'dev' must be
+ *  /dev/md/'name'NN or 'name'NN
+ * If it doesn't end with a digit string, it must be /dev/md/'name'
+ * or 'name' or must be NULL.
+ * If the digit string is present, it gives the minor number to use
+ * If not, we choose a high, unused minor number.
+ * If the 'dev' is a standard name, it devices whether 'md' or 'mdp'.
+ * else if the name is 'd[0-9]+' then we use mdp
+ * else if trustworthy is 'METADATA' we use md
+ * else the choice depends on 'autof'.
+ * If name is NULL it is assumed to match whatever dev provides.
+ * If both name and dev are NULL, we choose a name 'mdXX' or 'mdpXX'
+ *
+ * If 'name' is given, and 'trustworthy' is 'foreign' and name is not
+ * supported by 'dev', we add a "_%d" suffix based on the minor number
+ * use that.
+ *
+ * If udev is configured, we create a temporary device, open it, and 
+ * unlink it.
+ * If not, we create the /dev/mdXX device, and is name is usable,
+ * /dev/md/name
+ * In any case we return /dev/md/name or (if that isn't available)
+ * /dev/mdXX in 'chosen'.
+ *
+ * When we create devices, we use uid/gid/umask from config file.
  */
-int create_mddev(char *dev, int autof)
+
+int create_mddev(char *dev, char *name, int autof, int trustworthy,
+		 char *chosen)
 {
 	int mdfd;
 	struct stat stb;
-	int major_num = MD_MAJOR;
-	int minor_num = 0;
-	int must_remove = 0;
-	int num;
+	int num = -1;
+	int use_mdp = -1;
 	struct createinfo *ci = conf_get_create_info();
 	int parts;
+	char *cname;
+	char devname[20];
+	char cbuf[400];
+	if (chosen == NULL)
+		chosen = cbuf;
+
 
 	if (autof == 0)
 		autof = ci->autof;
@@ -123,141 +153,187 @@ int create_mddev(char *dev, int autof)
 	parts = autof >> 3;
 	autof &= 7;
 
-	if (autof && autof != 1) {
-		/* autof is set, so we need to check that the name is ok,
-		 * and possibly create one if not
+	strcpy(chosen, "/dev/md/");
+	cname = chosen + strlen(chosen);
+
+
+	if (dev) {
+		
+		if (strncmp(dev, "/dev/md/", 8) == 0) {
+			strcpy(cname, dev+8);
+		} else if (strncmp(dev, "/dev/", 5) == 0) {
+			char *e = dev + strlen(dev);
+			while (e > dev && isdigit(e[-1]))
+				e--;
+			if (e[0])
+				num = strtoul(e, NULL, 10);
+			strcpy(cname, dev+5);
+			cname[e-(dev+5)] = 0;
+			/* name *must* be mdXX or md_dXX in this context */
+			if (num < 0 ||
+			    (strcmp(cname, "md") != 0 && strcmp(cname, "md_d") != 0)) {
+				fprintf(stderr, Name ": %s is an invalid name "
+					"for an md device.  Try /dev/md/%s\n",
+					dev, dev+5);
+				return -1;
+			}
+			if (strcmp(cname, "md") == 0)
+				use_mdp = 0;
+			else
+				use_mdp = 1;
+		} else
+			strcpy(cname, dev);
+
+		/* 'cname' must not contain a slash, may not start or end 
+		 * with a digit, and may only be empty if num is present.
 		 */
-		int std;
-		stb.st_mode = 0;
-		if (stat(dev, &stb)==0 && ! S_ISBLK(stb.st_mode)) {
-			fprintf(stderr, Name ": %s is not a block device.\n",
+		if (strchr(cname, '/') != NULL ||
+		    isdigit(cname[0]) ||
+		    (cname[0] && isdigit(cname[strlen(cname)]))
+			) {
+			fprintf(stderr, Name ": %s is an invalid name "
+				"for an md device.\n", dev);
+			return -1;
+		}
+		if (cname[0] == 0 && num < 0) {
+			fprintf(stderr, Name ": %s is an invalid name "
+				"for an md device (empty!).", dev);
+			return -1;
+		}
+	}
+
+	/* Now determine device number */
+	/* named 'METADATA' cannot use 'mdp'. */
+	if (name && name[0] == 0)
+		name = NULL;
+	if (name && trustworthy == METADATA && use_mdp == 1) {
+		fprintf(stderr, Name ": %s is not allowed for a %s container. "
+			"Consider /dev/md%d.\n", dev, name, num);
+		return -1;
+	}
+	if (name && trustworthy == METADATA)
+		use_mdp = 0;
+	if (use_mdp == -1) {
+		if (autof == 4 || autof == 6)
+			use_mdp = 1;
+		else
+			use_mdp = 0;
+	}
+	if (num < 0 && trustworthy == LOCAL && name) {
+		/* if name is numeric, us that for num */
+		char *ep;
+		num = strtoul(name, &ep, 10);
+		if (ep == name || *ep)
+			num = -1;
+	}
+
+	if (num < 0) {
+		/* need to choose a free number. */
+		num = find_free_devnum(use_mdp);
+		if (num == NoMdDev) {
+			fprintf(stderr, Name ": No avail md devices - aborting\n");
+			return -1;
+		}
+	} else {
+		num = use_mdp ? (-1-num) : num;
+		if (mddev_busy(num)) {
+			fprintf(stderr, Name ": %s is already in use.\n",
 				dev);
 			return -1;
 		}
-		/* check major number is correct */
-		num = -1;
-		std = is_standard(dev, &num);
-		if (std>0) major_num = get_mdp_major();
-		switch(autof) {
-		case 2: /* only create is_standard names */
-			if (!std && !stb.st_mode) {
-				fprintf(stderr, Name
-			": %s does not exist and is not a 'standard' name "
-			"so it cannot be created\n", dev);
-				return -1;
-			}
-			break;
-		case 3: /* create md, reject std>0 */
-			if (std > 0) {
-				fprintf(stderr, Name ": that --auto option "
-				"not compatable with device named %s\n", dev);
-				return -1;
-			}
-			break;
-		case 4: /* create mdp, reject std<0 */
-			if (std < 0) {
-				fprintf(stderr, Name ": that --auto option "
-				"not compatable with device named %s\n", dev);
-				return -1;
-			}
-			major_num = get_mdp_major();
-			break;
-		case 5: /* default to md if not standard */
-			break;
-		case 6: /* default to mdp if not standard */
-			if (std == 0) major_num = get_mdp_major();
-			break;
-		}
-		/* major is final. num is -1 if not standard */
-		if (stb.st_mode && major(stb.st_rdev) != major_num)
-			must_remove = 1;
-		if (stb.st_mode && !must_remove) {
-			/* looks ok, see if it is available */
-			mdfd = open(dev, O_RDWR);
-			if (mdfd < 0) {
-				fprintf(stderr, Name ": error opening %s: %s\n",
-					dev, strerror(errno));
-				return -1;
-			} else if (md_get_version(mdfd) <= 0) {
-				fprintf(stderr, Name ": %s does not appear to be an md device\n",
-					dev);
-				close(mdfd);
-				return -1;
-			}
-			if (major_num != MD_MAJOR && parts > 0)
-				make_parts(dev, parts, ci->symlinks);
-			return mdfd;
-		}
-		/* Ok, need to find a minor that is not in use.
-		 * If the device name is in a 'standard' format,
-		 * intuit the minor from that, else
-		 * easiest to read /proc/mdstat, and hunt through for
-		 * an unused number
+	}
+
+	if (num < 0)
+		sprintf(devname, "/dev/md_d%d", -1-num);
+	else
+		sprintf(devname, "/dev/md%d", num);
+
+	if (cname[0] == 0 && name) {
+		/* Need to find a name if we can
+		 * We don't completely trust 'name'.  Truncate to
+		 * reasonable length and remove '/'
 		 */
-		if (num < 0) {
-			/* need to pick an unused number */
-			int num = find_free_devnum(major_num != MD_MAJOR);
+		char *cp;
+		strncpy(cname, name, 200);
+		cname[200] = 0;
+		while ((cp = strchr(cname, '/')) != NULL)
+			*cp = '-';
+		if (trustworthy == METADATA)
+			/* always add device number to metadata */
+			sprintf(cname+strlen(cname), "%d", num);
+		else if (trustworthy == FOREIGN &&
+			 strchr(cname, ':') == NULL)
+			/* add _%d to FOREIGN array that don't have
+			 * a 'host:' prefix
+			 */
+			sprintf(cname+strlen(cname), "_%d", num<0?(-1-num):num);
+	}
+	if (cname[0] == 0)
+		strcpy(chosen, devname);
 
-			if (major_num == MD_MAJOR)
-				minor_num = num;
-			else
-				minor_num = (-1-num) << MdpMinorShift;
-		} else if (major_num == MD_MAJOR)
-			minor_num = num;
-		else
-			minor_num = num << MdpMinorShift;
-		/* major and minor have been chosen */
-
-		/* If it was a 'standard' name and it is in-use, then
-		 * the device could already be correct
-		 */
-		if (stb.st_mode && major(stb.st_rdev) == major_num &&
-		    minor(stb.st_rdev) == minor_num)
-			;
-		else {
-			if (major(makedev(major_num,minor_num)) != major_num ||
-			    minor(makedev(major_num,minor_num)) != minor_num) {
-				fprintf(stderr, Name ": Need newer C library to use more than 4 partitionable md devices, sorry\n");
+	/* We have a device number and name.
+	 * If we can detect udev, just open the device and we
+	 * are done.
+	 */
+	if (stat("/dev/.udev", &stb) != 0 ||
+	    check_env("MDADM_NO_UDEV")) {
+		/* Make sure 'devname' exists and 'chosen' is a symlink to it */
+		if (lstat(devname, &stb) == 0) {
+			/* Must be the correct device, else error */
+			if ((stb.st_mode&S_IFMT) != S_IFBLK ||
+			    stb.st_rdev != makedev(dev2major(num),dev2minor(num))) {
+				fprintf(stderr, Name ": %s exists but looks wrong, please fix\n",
+					devname);
 				return -1;
 			}
-			if (must_remove)
-				unlink(dev);
+		} else {
+			if (mknod(devname, S_IFBLK|0600,
+				  makedev(dev2major(num),dev2minor(num))) != 0) {
+				fprintf(stderr, Name ": failed to create %s\n",
+					devname);
+				return -1;
+			}
+			if (chown(devname, ci->uid, ci->gid))
+				perror("chown");
+			if (chmod(devname, ci->mode))
+				perror("chmod");
+			stat(devname, &stb);
+			add_dev(devname, &stb, 0, NULL);
+		}
+		if (strcmp(chosen, devname) != 0) {
 
-			if (strncmp(dev, "/dev/md/", 8) == 0) {
-				if (mkdir("/dev/md",0700)==0) {
-					if (chown("/dev/md", ci->uid, ci->gid))
-						perror("chown /dev/md");
-					if (chmod("/dev/md", ci->mode| ((ci->mode>>2) & 0111)))
-						perror("chmod /dev/md");
+			if (mkdir("/dev/md",0700)==0) {
+				if (chown("/dev/md", ci->uid, ci->gid))
+					perror("chown /dev/md");
+				if (chmod("/dev/md", ci->mode| ((ci->mode>>2) & 0111)))
+					perror("chmod /dev/md");
+			}
+
+			if (dev && strcmp(chosen, dev) == 0)
+				/* We know we are allowed to use this name */
+				unlink(chosen);
+
+			if (lstat(chosen, &stb) == 0) {
+				char buf[300];
+				if ((stb.st_mode & S_IFMT) != S_IFLNK ||
+				    readlink(chosen, buf, 300) <0 ||
+				    strcmp(buf, devname) != 0) {
+					fprintf(stderr, Name ": %s exists - ignoring\n",
+						chosen);
+					strcpy(chosen, devname);
 				}
-			}
-			if (mknod(dev, S_IFBLK|0600, makedev(major_num, minor_num))!= 0) {
-				fprintf(stderr, Name ": failed to create %s\n", dev);
-				return -1;
-			}
-			if (must_remove) {
-				if (chown(dev, stb.st_uid, stb.st_gid))
-					perror("chown");
-				if (chmod(dev, stb.st_mode & 07777))
-					perror("chmod");
-			} else {
-				if (chown(dev, ci->uid, ci->gid))
-					perror("chown");
-				if (chmod(dev, ci->mode))
-					perror("chmod");
-			}
-			stat(dev, &stb);
-			add_dev(dev, &stb, 0, NULL);
-			if (ci->symlinks && strncmp(dev, "/dev/md/", 8) == 0)
-				make_dev_symlink(dev);
-			if (major_num != MD_MAJOR)
-				make_parts(dev,parts, ci->symlinks);
+			} else
+				symlink(devname, chosen);
 		}
 	}
-	mdfd = open_mddev(dev, 1);
+	mdfd = open_dev_excl(num);
+	if (mdfd < 0)
+		fprintf(stderr, Name ": unexpected failure opening %s\n",
+			devname);
 	return mdfd;
 }
 
+
 /* Open this and check that it is an md device.
  * On success, return filedescriptor.
  * On failure, return -1 if it doesn't exist,