Reorganise Assemble code somewhat.

We make sure all devices can are consistent before doing any --update
This saves us from updating some but not all of an array, and then
aborting.

It also means we can backtrack on out decisions, which we might want to
do later.

Signed-off-by: Neil Brown <neilb@suse.de>

2 files changed, 31 insertions, 7 deletions

diff --git a/Assemble.c b/Assemble.c
index d35aa5a..ecee624 100644
--- a/Assemble.c
+++ b/Assemble.c
@@ -193,15 +193,18 @@ int Assemble(struct supertype *st, char *mddev, int mdfd,
 	    fprintf(stderr, Name ": looking for devices for %s\n",
 		    mddev);
 
-	while ( devlist) {
-		char *devname;
+	/* first walk the list of devices to find a consistent set
+	 * that match the criterea, if that is possible.
+	 * We flag the one we like with 'used'.
+	 */
+	for (tmpdev = devlist;
+	     tmpdev;
+	     tmpdev = tmpdev->next) {
+		char *devname = tmpdev->devname;
 		int dfd;
 		struct stat stb;
 		struct supertype *tst = st;
 
-		devname = devlist->devname;
-		devlist = devlist->next;
-
 		if (ident->devices &&
 		    !match_oneof(ident->devices, devname)) {
 			if ((inargv && verbose>=0) || verbose > 0)
@@ -296,12 +299,19 @@ int Assemble(struct supertype *st, char *mddev, int mdfd,
 			return 1;
 		}
 
+		tmpdev->used = 1;
+	}
+
+	/* Ok, no bad inconsistancy, we can try updating etc */
+	for (tmpdev = devlist; tmpdev; tmpdev=tmpdev->next) if (tmpdev->used) {
+		char *devname = tmpdev->devname;
+		struct stat stb;
 		/* looks like a good enough match to update the super block if needed */
 		if (update) {
+			int dfd;
 			/* prepare useful information in info structures */
 			struct stat stb2;
 			fstat(mdfd, &stb2);
-			info.array.md_minor = minor(stb2.st_rdev);
 
 			if (strcmp(update, "uuid")==0 &&
 			    !ident->uuid_set) {
@@ -315,8 +325,20 @@ int Assemble(struct supertype *st, char *mddev, int mdfd,
 				}
 				if (rfd >= 0) close(rfd);
 			}
+			dfd = dev_open(devname, O_RDWR|O_EXCL);
+
+			if (super) {
+				free(super);
+				super = NULL;
+			}
+
+			st->ss->load_super(st, dfd, &super, NULL);
+			st->ss->getinfo_super(&info, super);
+
 			memcpy(info.uuid, ident->uuid, 16);
 			strcpy(info.name, ident->name);
+			info.array.md_minor = minor(stb2.st_rdev);
+
 			st->ss->update_super(&info, super, update, devname, verbose,
 					     ident->uuid_set, homehost);
 			if (strcmp(update, "uuid")==0 &&
@@ -324,7 +346,6 @@ int Assemble(struct supertype *st, char *mddev, int mdfd,
 				ident->uuid_set = 1;
 				memcpy(ident->uuid, info.uuid, 16);
 			}
-			dfd = dev_open(devname, O_RDWR|O_EXCL);
 			if (dfd < 0)
 				fprintf(stderr, Name ": Cannot open %s for superblock update\n",
 					devname);
@@ -339,6 +360,8 @@ int Assemble(struct supertype *st, char *mddev, int mdfd,
 				bitmap_update_uuid(ident->bitmap_fd, info.uuid);
 		}
 
+		stat(devname, &stb);
+
 		if (verbose > 0)
 			fprintf(stderr, Name ": %s is identified as a member of %s, slot %d.\n",
 				devname, mddev, info.disk.raid_disk);
diff --git a/mdadm.h b/mdadm.h
index ecaacd4..94e4708 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -182,6 +182,7 @@ typedef struct mddev_dev_s {
 				 */
 	char writemostly;
 	char re_add;
+	char used;		/* set when used */
 	struct mddev_dev_s *next;
 } *mddev_dev_t;