Add support for internal bitmaps

For version 0.90 superblocks, an internal bitmap can be specified at create.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>

Create.c

@@ -341,11 +341,26 @@ int Create(struct supertype *st, char *mddev, int mdfd,
 	array.nr_disks = array.working_disks + array.failed_disks;
 	array.layout = layout;
 	array.chunk_size = chunk*1024;
-	printf("VERS = %d\n", vers);
+
 
 	if (!st->ss->init_super(&super, &array))
 		return 1;
 
+	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(super, bitmap_chunk, delay, 
+						 size ? size : maxsize)) {
+			fprintf(stderr, Name ": Given bitmap chunk size not supported.\n");
+			return 1;
+		}
+		bitmap_file = NULL;
+	}
+
+
+
 	if ((vers % 100) >= 1) { /* can use different versions */
 		mdu_array_info_t inf;
 		memset(&inf, 0, sizeof(inf));
@@ -362,6 +377,10 @@ int Create(struct supertype *st, char *mddev, int mdfd,
 
 	if (bitmap_file) {
 		int uuid[4];
+
+		if (bitmap_chunk == UnSet)
+			bitmap_chunk = DEFAULT_BITMAP_CHUNK;
+
 		st->ss->uuid_from_super(uuid, super);
 		if (CreateBitmap(bitmap_file, force, (char*)uuid, bitmap_chunk, delay,
 				 array.size*2ULL /* FIXME wrong for raid10 */)) {

bitmap.c

@@ -177,10 +177,11 @@ out:
 	return info;
 }
 
-bitmap_info_t *bitmap_file_read(char *filename, int brief)
+bitmap_info_t *bitmap_file_read(char *filename, int brief, struct supertype *st)
 {
 	int fd;
 	bitmap_info_t *info;
+	struct stat stb;
 
 	fd = open(filename, O_RDONLY);
 	if (fd < 0) {
@@ -188,13 +189,24 @@ bitmap_info_t *bitmap_file_read(char *filename, int brief)
 				filename, strerror(errno));
 		return NULL;
 	}
+	fstat(fd, &stb);
+	if ((S_IFMT & stb.st_mode) == S_IFBLK) {
+		/* block device, so we are probably after an internal bitmap */
+		if (!st) st = guess_super(fd);
+		if (!st) {
+			/* just look at device... */
+			lseek(fd, 0, 0);
+		} else {	
+			st->ss->locate_bitmap(st, fd);
+		}
+	}
 
 	info = bitmap_fd_read(fd, brief);
 	close(fd);
 	return info;
 }
 
-int ExamineBitmap(char *filename, int brief)
+int ExamineBitmap(char *filename, int brief, struct supertype *st)
 {
 	/*
 	 * Read the bitmap file and display its contents
@@ -204,7 +216,7 @@ int ExamineBitmap(char *filename, int brief)
 	bitmap_info_t *info;
 	int rv = 1;
 
-	info = bitmap_file_read(filename, brief);
+	info = bitmap_file_read(filename, brief, st);
 	if (!info)
 		return rv;
 

md_p.h

@@ -96,6 +96,8 @@ typedef struct mdp_device_descriptor_s {
 #define MD_SB_CLEAN		0
 #define MD_SB_ERRORS		1
 
+#define	MD_SB_BITMAP_PRESENT	8 /* bitmap may be present nearby */
+
 typedef struct mdp_superblock_s {
 	/*
 	 * Constant generic information

mdadm.c

@@ -698,6 +698,10 @@ int main(int argc, char *argv[])
 				fprintf(stderr, Name ": bitmap file needed with -b in --assemble mode\n");
 				exit(2);
 			}
+			if (strcmp(optarg, "internal")==0) {
+				fprintf(stderr, Name ": there is no need to specify --bitmap when assembling arrays with internal bitmaps\n");
+				continue;
+			}
 			bitmap_fd = open(optarg, O_RDWR);
 			if (!*optarg || bitmap_fd < 0) {
 				fprintf(stderr, Name ": cannot open bitmap file %s: %s\n", optarg, strerror(errno));
@@ -863,6 +867,11 @@ int main(int argc, char *argv[])
 		if (bitmap_chunk == UnSet) bitmap_chunk = DEFAULT_BITMAP_CHUNK;
 		if (delay == 0) delay = DEFAULT_BITMAP_DELAY;
 		if (bitmap_file) {
+			if (strcmp(bitmap_file, "internal")==0) {
+				fprintf(stderr, Name ": 'internal' bitmaps not supported with --build\n");
+				rv |= 1;
+				break;
+			}
 			bitmap_fd = open(bitmap_file, O_RDWR,0);
 			if (bitmap_fd < 0 && errno != ENOENT) {
 				perror(Name ": cannot create bitmap file");
@@ -879,7 +888,6 @@ int main(int argc, char *argv[])
 			   bitmap_file, bitmap_chunk, delay);
 		break;
 	case CREATE:
-		if (bitmap_chunk == UnSet) bitmap_chunk = DEFAULT_BITMAP_CHUNK;
 		if (delay == 0) delay = DEFAULT_BITMAP_DELAY;
 		if (ss == NULL) {
 			for(i=0; !ss && superlist[i]; i++) 
@@ -958,7 +966,7 @@ int main(int argc, char *argv[])
 				case 'Q':
 					rv |= Query(dv->devname); continue;
 				case 'X':
-					rv |= ExamineBitmap(dv->devname, brief); continue;
+					rv |= ExamineBitmap(dv->devname, brief, ss); continue;
 				}
 				mdfd = open_mddev(dv->devname, 0);
 				if (mdfd>=0) {

mdadm.h

@@ -185,6 +185,8 @@ 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)(__u64 size);
+	int (*add_internal_bitmap)(void *sbv, int chunk, int delay, unsigned long long size);
+	void (*locate_bitmap)(struct supertype *st, int fd);
 	int major;
 } super0, super1, *superlist[];
 
@@ -240,7 +242,7 @@ 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 long array_size);
-extern int ExamineBitmap(char *filename, int brief);
+extern int ExamineBitmap(char *filename, int brief, struct supertype *st);
 
 extern int md_get_version(int fd);
 extern int get_linux_version(void);

super0.c

@@ -28,6 +28,7 @@
  */
 
 #include "mdadm.h"
+#include <asm/byteorder.h>
 
 /*
  * All handling for the 0.90.0 version superblock is in
@@ -81,6 +82,8 @@ static void examine_super0(void *sbv)
 	printf("    Update Time : %.24s\n", ctime(&atime));
 	printf("          State : %s\n",
 	       (sb->state&(1<<MD_SB_CLEAN))?"clean":"active");
+	if (sb->state & (1<<MD_SB_BITMAP_PRESENT))
+		printf("Internal Bitmap : present\n");
 	printf(" Active Devices : %d\n", sb->active_disks);
 	printf("Working Devices : %d\n", sb->working_disks);
 	printf(" Failed Devices : %d\n", sb->failed_disks);
@@ -324,10 +327,10 @@ static __u64 event_super0(void *sbv)
 
 static int init_super0(void **sbp, mdu_array_info_t *info)
 {
-	mdp_super_t *sb = malloc(MD_SB_BYTES);
+	mdp_super_t *sb = malloc(MD_SB_BYTES + sizeof(bitmap_super_t));
 	int spares;
 	int rfd;
-	memset(sb, 0, MD_SB_BYTES);
+	memset(sb, 0, MD_SB_BYTES + sizeof(bitmap_super_t));
 
 	if (info->major_version == -1) {
 		/* zeroing the superblock */
@@ -441,6 +444,27 @@ static int write_init_super0(struct supertype *st, void *sbv, mdu_disk_info_t *d
 	sb->this_disk = sb->disks[dinfo->number];
 	sb->sb_csum = calc_sb0_csum(sb);
 	rv = store_super0(fd, sb);
+
+	if (sb->state & (1<<MD_SB_BITMAP_PRESENT)) {
+		int towrite, n;
+		char buf[4096];
+		write(fd, ((char*)sb)+MD_SB_BYTES, sizeof(bitmap_super_t));
+		towrite = 64*1024 - MD_SB_BYTES - sizeof(bitmap_super_t);
+		memset(buf, 0xff, sizeof(buf));
+		while (towrite > 0) {
+			n = towrite;
+			if (n > sizeof(buf)) 
+				n = sizeof(buf);
+			n = write(fd, buf, n);
+			if (n > 0)
+				towrite -= n;
+			else
+				break;
+		}
+		if (towrite)
+			rv = -2;
+	}
+
 	close(fd);
 	if (rv)
 		fprintf(stderr, Name ": failed to write superblock to %s\n", devname);
@@ -591,6 +615,75 @@ static __u64 avail_size0(__u64 devsize)
 	return MD_NEW_SIZE_SECTORS(devsize);
 }
 
+static int add_internal_bitmap0(void *sbv, int chunk, int delay, unsigned long long size)
+{
+	/*
+	 * The bitmap comes immediately after the superblock and must be 60K in size
+	 * at most.  The default size is between 30K and 60K
+	 *
+	 * size is in K,  chunk is in bytes !!!
+	 */
+
+	unsigned long long bits = size;
+	unsigned long long max_bits = 60*1024*8;
+	unsigned long long min_chunk;
+	mdp_super_t *sb = sbv;
+	bitmap_super_t *bms = (bitmap_super_t*)(((char*)sb) + MD_SB_BYTES);
+
+	
+	min_chunk = 1024;
+	while (bits > max_bits) {
+		min_chunk *= 2;
+		bits = (bits+1)/2;
+	}
+	if (chunk == UnSet)
+		chunk = min_chunk;
+	else if (chunk < min_chunk)
+		return 0; /* chunk size too small */
+
+	sb->state |= (1<<MD_SB_BITMAP_PRESENT);
+
+	bms->magic = __le32_to_cpu(BITMAP_MAGIC);
+	bms->version = __le32_to_cpu(BITMAP_MAJOR);
+	uuid_from_super0((int*)bms->uuid, sb);
+	bms->chunksize = __le32_to_cpu(chunk);
+	bms->daemon_sleep = __le32_to_cpu(delay);
+	bms->sync_size = __le64_to_cpu(size);
+
+
+	return 1;
+}
+		
+
+void locate_bitmap0(struct supertype *st, int fd)
+{
+	unsigned long long dsize;
+	unsigned long size;
+	unsigned long long offset;
+#ifdef BLKGETSIZE64
+	if (ioctl(fd, BLKGETSIZE64, &dsize) != 0)
+#endif
+	{
+		if (ioctl(fd, BLKGETSIZE, &size))
+			return;
+		else
+			dsize = ((unsigned long long)size)<<9;
+	}
+
+	if (dsize < MD_RESERVED_SECTORS*2)
+		return;
+	
+	offset = MD_NEW_SIZE_SECTORS(dsize>>9);
+
+	offset *= 512;
+
+	offset += MD_SB_BYTES;
+
+	lseek64(fd, offset, 0);
+}
+
+	
+
 struct superswitch super0 = {
 	.examine_super = examine_super0,
 	.brief_examine_super = brief_examine_super0,
@@ -608,5 +701,7 @@ struct superswitch super0 = {
 	.load_super = load_super0,
 	.match_metadata_desc = match_metadata_desc0,
 	.avail_size = avail_size0,
+	.add_internal_bitmap = add_internal_bitmap0,
+	.locate_bitmap = locate_bitmap0,
 	.major = 0,
 };