Create version-4 bitmaps if kernel supports it.

Version-3 bitmaps are host-endian.  Version-4 are little-endian
and so more portable.

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

8 files changed, 55 insertions, 18 deletions

diff --git a/Build.c b/Build.c
index 689aad0..2fcc47e 100644
--- a/Build.c
+++ b/Build.c
@@ -202,13 +202,21 @@ int Build(char *mddev, int mdfd, int chunk, int level, int layout,
 		if (bitmap_file) {
 			bitmap_fd = open(bitmap_file, O_RDWR);
 			if (bitmap_fd < 0) {
+				int major = BITMAP_MAJOR_HI;
 				if (bitmap_chunk == UnSet) {
 					fprintf(stderr, Name ": %s cannot be openned.",
 						bitmap_file);
 					return 1;
 				}
+				if (vers < 9003) {
+					major = BITMAP_MAJOR_HOSTENDIAN;
+#ifdef __BIG_ENDIAN
+					fprintf(stderr, Name ": Warning - bitmaps created on this kernel are not portable\n"
+						"  between different architectured.  Consider upgrading the Linux kernel.\n");
+#endif
+				}
 				if (CreateBitmap(bitmap_file, 1, NULL, bitmap_chunk,
-						 delay, write_behind, size>>9)) {
+						 delay, write_behind, size>>9, major)) {
 					return 1;
 				}
 				bitmap_fd = open(bitmap_file, O_RDWR);
diff --git a/Create.c b/Create.c
index 34435d5..148ab0e 100644
--- a/Create.c
+++ b/Create.c
@@ -71,7 +71,8 @@ int Create(struct supertype *st, char *mddev, int mdfd,
 	int bitmap_fd;
 
 	mdu_array_info_t array;
-	
+	int major = BITMAP_MAJOR_HI;
+
 	vers = md_get_version(mdfd);
 	if (vers < 9000) {
 		fprintf(stderr, Name ": Create requires md driver version 0.90.0 or later\n");
@@ -350,13 +351,21 @@ int Create(struct supertype *st, char *mddev, int mdfd,
 	if (!st->ss->init_super(st, &super, &array, name))
 		return 1;
 
+	if (bitmap_file && vers < 9003) {
+		major = BITMAP_MAJOR_HOSTENDIAN;
+#ifdef __BIG_ENDIAN
+		fprintf(stderr, Name ": Warning - bitmaps created on this kernel are not portable\n"
+			"  between different architectured.  Consider upgrading the Linux kernel.\n");
+#endif
+	}
+
 	if (bitmap_file && strcmp(bitmap_file, "internal")==0) {
 		if ((vers%100) < 2) {
 			fprintf(stderr, Name ": internal bitmaps not supported by this kernel.\n");
 			return 1;
 		}
 		if (!st->ss->add_internal_bitmap(st, super, bitmap_chunk, delay, write_behind,
-						 &array.size, 1)) {
+						 &array.size, 1, major)) {
 			fprintf(stderr, Name ": Given bitmap chunk size not supported.\n");
 			return 1;
 		}
@@ -387,14 +396,15 @@ int Create(struct supertype *st, char *mddev, int mdfd,
 
 		st->ss->uuid_from_super(uuid, super);
 		if (CreateBitmap(bitmap_file, force, (char*)uuid, bitmap_chunk,
-			delay, write_behind,
-				 array.size*2ULL /* FIXME wrong for raid10 */)) {
+				 delay, write_behind,
+				 array.size*2ULL /* FIXME wrong for raid10 */,
+				 major)) {
 			return 1;
 		}
 		bitmap_fd = open(bitmap_file, O_RDWR);
 		if (bitmap_fd < 0) {
 			fprintf(stderr, Name ": weird: %s cannot be openned\n",
-			       bitmap_file);
+				bitmap_file);
 			return 1;
 		}
 		if (ioctl(mdfd, SET_BITMAP_FILE, bitmap_fd) < 0) {
diff --git a/Grow.c b/Grow.c
index 91278e8..aa14638 100644
--- a/Grow.c
+++ b/Grow.c
@@ -206,6 +206,16 @@ int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int
 	mdu_bitmap_file_t bmf;
 	mdu_array_info_t array;
 	struct supertype *st;
+	int major = BITMAP_MAJOR_HI;
+	int vers = md_get_version(fd);
+
+	if (vers < 9003) {
+		major = BITMAP_MAJOR_HOSTENDIAN;
+#ifdef __BIG_ENDIAN
+		fprintf(stderr, Name ": Warning - bitmaps created on this kernel are not portable\n"
+			"  between different architectured.  Consider upgrading the Linux kernel.\n");
+#endif
+	}
 
 	if (ioctl(fd, GET_BITMAP_FILE, &bmf) != 0) {
 		if (errno == ENOMEM) 
@@ -275,7 +285,7 @@ int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int
 				if (st->ss->load_super(st, fd2, &super, NULL)==0) {
 					st->ss->add_internal_bitmap(st, super,
 								    chunk, delay, write_behind,
-								    &array.size, 0);
+								    &array.size, 0, major);
 					st->ss->write_bitmap(st, fd2, super);
 				}
 				close(fd2);
@@ -322,7 +332,7 @@ int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int
 			return 1;
 		}
 		if (CreateBitmap(file, 0, (char*)uuid, chunk,
-				 delay, write_behind, array.size*2ULL)) {
+				 delay, write_behind, array.size*2ULL, major)) {
 			return 1;
 		}
 		bitmap_fd = open(file, O_RDWR);
diff --git a/bitmap.c b/bitmap.c
index 82da00a..bc29768 100644
--- a/bitmap.c
+++ b/bitmap.c
@@ -243,7 +243,8 @@ int ExamineBitmap(char *filename, int brief, struct supertype *st)
 		fprintf(stderr, Name ": invalid bitmap magic 0x%x, the bitmap file appears to be corrupted\n", sb->magic);
 	}
 	printf("         Version : %d\n", sb->version);
-	if (sb->version != BITMAP_MAJOR) {
+	if (sb->version < BITMAP_MAJOR_LO ||
+	    sb->version > BITMAP_MAJOR_HI) {
 		fprintf(stderr, Name ": unknown bitmap version %d, either the bitmap file is corrupted or you need to upgrade your tools\n", sb->version);
 		goto free_info;
 	}
@@ -287,7 +288,8 @@ free_info:
 int CreateBitmap(char *filename, int force, char uuid[16],
 		 unsigned long chunksize, unsigned long daemon_sleep,
 		 unsigned long write_behind,
-		 unsigned long long array_size /* sectors */)
+		 unsigned long long array_size /* sectors */,
+		 int major)
 {
 	/*
 	 * Create a bitmap file with a superblock and (optionally) a full bitmap
@@ -313,7 +315,7 @@ int CreateBitmap(char *filename, int force, char uuid[16],
 
 	memset(&sb, 0, sizeof(sb));
 	sb.magic = BITMAP_MAGIC;
-	sb.version = BITMAP_MAJOR;
+	sb.version = major;
 	if (uuid != NULL)
 		memcpy(sb.uuid, uuid, 16);
 	sb.chunksize = chunksize;
diff --git a/bitmap.h b/bitmap.h
index 02a4e97..055661d 100644
--- a/bitmap.h
+++ b/bitmap.h
@@ -6,7 +6,13 @@
 #ifndef BITMAP_H
 #define BITMAP_H 1
 
-#define BITMAP_MAJOR 3
+#define BITMAP_MAJOR_LO 3
+/* version 4 insists the bitmap is in little-endian order
+ * with version 3, it is host-endian which is non-portable
+ */
+#define BITMAP_MAJOR_HI 4
+#define	BITMAP_MAJOR_HOSTENDIAN 3
+
 #define BITMAP_MINOR 39
 
 /*
diff --git a/mdadm.h b/mdadm.h
index 3557c02..85a853b 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -190,7 +190,7 @@ extern struct superswitch {
 	int (*load_super)(struct supertype *st, int fd, void **sbp, char *devname);
 	struct supertype * (*match_metadata_desc)(char *arg);
 	__u64 (*avail_size)(struct supertype *st, __u64 size);
-	int (*add_internal_bitmap)(struct supertype *st, void *sbv, int chunk, int delay, int write_behind, int *sizep, int may_change);
+	int (*add_internal_bitmap)(struct supertype *st, void *sbv, int chunk, int delay, int write_behind, int *sizep, int may_change, int major);
 	void (*locate_bitmap)(struct supertype *st, int fd, void *sbv);
 	int (*write_bitmap)(struct supertype *st, int fd, void *sbv);
 	int major;
@@ -265,7 +265,8 @@ extern int Kill(char *dev, int force);
 extern int CreateBitmap(char *filename, int force, char uuid[16],
 			unsigned long chunksize, unsigned long daemon_sleep,
 			unsigned long write_behind,
-			unsigned long long array_size);
+			unsigned long long array_size,
+			int major);
 extern int ExamineBitmap(char *filename, int brief, struct supertype *st);
 
 extern int md_get_version(int fd);
diff --git a/super0.c b/super0.c
index 95968d3..4ab40af 100644
--- a/super0.c
+++ b/super0.c
@@ -657,7 +657,7 @@ static __u64 avail_size0(struct supertype *st, __u64 devsize)
 	return MD_NEW_SIZE_SECTORS(devsize);
 }
 
-static int add_internal_bitmap0(struct supertype *st, void *sbv, int chunk, int delay, int write_behind, int *sizep, int may_change)
+static int add_internal_bitmap0(struct supertype *st, void *sbv, int chunk, int delay, int write_behind, int *sizep, int may_change, int major)
 {
 	/*
 	 * The bitmap comes immediately after the superblock and must be 60K in size
@@ -688,7 +688,7 @@ static int add_internal_bitmap0(struct supertype *st, void *sbv, int chunk, int
 
 	memset(bms, sizeof(*bms), 0);
 	bms->magic = __cpu_to_le32(BITMAP_MAGIC);
-	bms->version = __cpu_to_le32(BITMAP_MAJOR);
+	bms->version = __cpu_to_le32(major);
 	uuid_from_super0((int*)bms->uuid, sb);
 	bms->chunksize = __cpu_to_le32(chunk);
 	bms->daemon_sleep = __cpu_to_le32(delay);
diff --git a/super1.c b/super1.c
index 4479dff..46ce82d 100644
--- a/super1.c
+++ b/super1.c
@@ -842,7 +842,7 @@ static __u64 avail_size1(struct supertype *st, __u64 devsize)
 
 static int
 add_internal_bitmap1(struct supertype *st, void *sbv,
-		     int chunk, int delay, int write_behind, int *sizep, int may_change)
+		     int chunk, int delay, int write_behind, int *sizep, int may_change, int major)
 {
 	/*
 	 * If not may_change, then this is a 'Grow', and the bitmap
@@ -883,7 +883,7 @@ add_internal_bitmap1(struct supertype *st, void *sbv,
 	sb->feature_map = __cpu_to_le32(__le32_to_cpu(sb->feature_map) | 1);
 	memset(bms, sizeof(*bms), 0);
 	bms->magic = __cpu_to_le32(BITMAP_MAGIC);
-	bms->version = __cpu_to_le32(BITMAP_MAJOR);
+	bms->version = __cpu_to_le32(major);
 	uuid_from_super1((int*)bms->uuid, sb);
 	bms->chunksize = __cpu_to_le32(chunk);
 	bms->daemon_sleep = __cpu_to_le32(delay);