mdadm/Detail: show correct state for clustered array

After kernel md module commit 480523feae581, in clustered env,
mddev->in_sync always zero, it will make array.state never set
up MD_SB_CLEAN. it causes "mdadm -D /dev/mdX" show state 'active'
all the time.

bitmap.c: add a new API IsBitmapDirty() to support inquiry bitmap
dirty or clean.

Signed-off-by: Zhao Heming <heming.zhao@suse.com>

Detail.c

@@ -498,8 +498,26 @@ int Detail(char *dev, struct context *c)
 							  sra->array_state);
 				else
 					arrayst = "clean";
-			} else
+			} else {
 				arrayst = "active";
+				if (array.state & (1<<MD_SB_CLUSTERED)) {
+					for (d = 0; d < max_disks * 2; d++) {
+						char *dv;
+						mdu_disk_info_t disk = disks[d];
+
+						/* only check first valid disk in cluster env */
+						if ((disk.state & (MD_DISK_SYNC | MD_DISK_ACTIVE))
+							&& (disk.major | disk.minor)) {
+							dv = map_dev_preferred(disk.major, disk.minor, 0,
+									c->prefer);
+							if (!dv)
+								continue;
+							arrayst = IsBitmapDirty(dv) ? "active" : "clean";
+							break;
+						}
+					}
+				}
+			}
 
 			printf("             State : %s%s%s%s%s%s%s \n",
 			       arrayst, st,

bitmap.c

@@ -180,13 +180,14 @@ out:
 }
 
 static int
-bitmap_file_open(char *filename, struct supertype **stp, int node_num)
+bitmap_file_open(char *filename, struct supertype **stp, int node_num, int fd)
 {
-	int fd;
 	struct stat stb;
 	struct supertype *st = *stp;
 
-	fd = open(filename, O_RDONLY|O_DIRECT);
+	/* won't re-open filename when (fd >= 0) */
+	if (fd < 0)
+		fd = open(filename, O_RDONLY|O_DIRECT);
 	if (fd < 0) {
 		pr_err("failed to open bitmap file %s: %s\n",
 		       filename, strerror(errno));
@@ -249,7 +250,7 @@ int ExamineBitmap(char *filename, int brief, struct supertype *st)
 	int fd, i;
 	__u32 uuid32[4];
 
-	fd = bitmap_file_open(filename, &st, 0);
+	fd = bitmap_file_open(filename, &st, 0, -1);
 	if (fd < 0)
 		return rv;
 
@@ -263,7 +264,6 @@ int ExamineBitmap(char *filename, int brief, struct supertype *st)
 		pr_err("Reporting bitmap that would be used if this array were used\n");
 		pr_err("as a member of some other array\n");
 	}
-	close(fd);
 	printf("        Filename : %s\n", filename);
 	printf("           Magic : %08x\n", sb->magic);
 	if (sb->magic != BITMAP_MAGIC) {
@@ -332,15 +332,13 @@ int ExamineBitmap(char *filename, int brief, struct supertype *st)
 		for (i = 0; i < (int)sb->nodes; i++) {
 			st = NULL;
 			free(info);
-			fd = bitmap_file_open(filename, &st, i);
+			fd = bitmap_file_open(filename, &st, i, fd);
 			if (fd < 0) {
 				printf("   Unable to open bitmap file on node: %i\n", i);
-
 				continue;
 			}
 			info = bitmap_fd_read(fd, brief);
 			if (!info) {
-				close(fd);
 				printf("   Unable to read bitmap on node: %i\n", i);
 				continue;
 			}
@@ -359,15 +357,74 @@ int ExamineBitmap(char *filename, int brief, struct supertype *st)
 			printf("          Bitmap : %llu bits (chunks), %llu dirty (%2.1f%%)\n",
 			       info->total_bits, info->dirty_bits,
 			       100.0 * info->dirty_bits / (info->total_bits?:1));
-			 close(fd);
 		}
 	}
 
 free_info:
+	close(fd);
 	free(info);
 	return rv;
 }
 
+int IsBitmapDirty(char *filename)
+{
+	/*
+	 * Read the bitmap file
+	 * It will break reading bitmap action immediately when meeting any error.
+	 *
+	 * Return: 1(dirty), 0 (clean), -1(error)
+	 */
+
+	int fd = -1, rv = 0, i;
+	struct supertype *st = NULL;
+	bitmap_info_t *info = NULL;
+	bitmap_super_t *sb = NULL;
+
+	fd = bitmap_file_open(filename, &st, 0, fd);
+	free(st);
+	if (fd < 0)
+		goto out;
+
+	info = bitmap_fd_read(fd, 0);
+	if (!info) {
+		close(fd);
+		goto out;
+	}
+
+	sb = &info->sb;
+	for (i = 0; i < (int)sb->nodes; i++) {
+		st = NULL;
+		free(info);
+		info = NULL;
+
+		fd = bitmap_file_open(filename, &st, i, fd);
+		free(st);
+		if (fd < 0)
+			goto out;
+
+		info = bitmap_fd_read(fd, 0);
+		if (!info) {
+			close(fd);
+			goto out;
+		}
+
+		sb = &info->sb;
+		if (sb->magic != BITMAP_MAGIC) { /* invalid bitmap magic */
+			free(info);
+			close(fd);
+			goto out;
+		}
+
+		if (info->dirty_bits)
+			rv = 1;
+	}
+	close(fd);
+	free(info);
+	return rv;
+out:
+	return -1;
+}
+
 int CreateBitmap(char *filename, int force, char uuid[16],
 		 unsigned long chunksize, unsigned long daemon_sleep,
 		 unsigned long write_behind,

mdadm.h

@@ -1455,6 +1455,7 @@ extern int CreateBitmap(char *filename, int force, char uuid[16],
 			unsigned long long array_size,
 			int major);
 extern int ExamineBitmap(char *filename, int brief, struct supertype *st);
+extern int IsBitmapDirty(char *filename);
 extern int Write_rules(char *rule_name);
 extern int bitmap_update_uuid(int fd, int *uuid, int swap);