[PATCH V2 22/23] mdrestore: Define mdrestore ops for v2 format

[Chandan Babu R <chandan.babu@oracle.com>]

This commit adds functionality to restore metadump stored in v2 format.

Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
---
 mdrestore/xfs_mdrestore.c | 251 +++++++++++++++++++++++++++++++++++---
 1 file changed, 233 insertions(+), 18 deletions(-)

diff --git a/mdrestore/xfs_mdrestore.c b/mdrestore/xfs_mdrestore.c
index c395ae90..7b484071 100644
--- a/mdrestore/xfs_mdrestore.c
+++ b/mdrestore/xfs_mdrestore.c
@@ -12,7 +12,8 @@ struct mdrestore_ops {
 	void (*read_header)(void *header, FILE *md_fp);
 	void (*show_info)(void *header, const char *md_file);
 	void (*restore)(void *header, FILE *md_fp, int ddev_fd,
-			bool is_target_file);
+			bool is_data_target_file, int logdev_fd,
+			bool is_log_target_file);
 };
 
 static struct mdrestore {
@@ -20,6 +21,7 @@ static struct mdrestore {
 	bool			show_progress;
 	bool			show_info;
 	bool			progress_since_warning;
+	bool			external_log;
 } mdrestore;
 
 static void
@@ -143,10 +145,12 @@ show_info_v1(
 
 static void
 restore_v1(
-	void			*header,
-	FILE			*md_fp,
-	int			ddev_fd,
-	bool			is_target_file)
+	void		*header,
+	FILE		*md_fp,
+	int		ddev_fd,
+	bool		is_data_target_file,
+	int		logdev_fd,
+	bool		is_log_target_file)
 {
 	struct xfs_metablock	*metablock;
 	struct xfs_metablock	*mbp;
@@ -203,7 +207,7 @@ restore_v1(
 
 	((struct xfs_dsb*)block_buffer)->sb_inprogress = 1;
 
-	verify_device_size(ddev_fd, is_target_file, sb.sb_dblocks,
+	verify_device_size(ddev_fd, is_data_target_file, sb.sb_dblocks,
 			sb.sb_blocksize);
 
 	bytes_read = 0;
@@ -264,6 +268,195 @@ static struct mdrestore_ops mdrestore_ops_v1 = {
 	.restore	= restore_v1,
 };
 
+static void
+read_header_v2(
+	void				*header,
+	FILE				*md_fp)
+{
+	struct xfs_metadump_header	*xmh = header;
+	bool				want_external_log;
+
+	xmh->xmh_magic = cpu_to_be32(XFS_MD_MAGIC_V2);
+
+	if (fread((uint8_t *)xmh + sizeof(xmh->xmh_magic),
+			sizeof(*xmh) - sizeof(xmh->xmh_magic), 1, md_fp) != 1)
+		fatal("error reading from metadump file\n");
+
+	want_external_log = !!(be32_to_cpu(xmh->xmh_incompat_flags) &
+			XFS_MD2_INCOMPAT_EXTERNALLOG);
+
+	if (want_external_log && !mdrestore.external_log)
+		fatal("External Log device is required\n");
+}
+
+static void
+show_info_v2(
+	void				*header,
+	const char			*md_file)
+{
+	struct xfs_metadump_header	*xmh;
+	uint32_t			incompat_flags;
+
+	xmh = header;
+	incompat_flags = be32_to_cpu(xmh->xmh_incompat_flags);
+
+	printf("%s: %sobfuscated, %s log, external log contents are %sdumped, %s metadata blocks,\n",
+		md_file,
+		incompat_flags & XFS_MD2_INCOMPAT_OBFUSCATED ? "":"not ",
+		incompat_flags & XFS_MD2_INCOMPAT_DIRTYLOG ? "dirty":"clean",
+		incompat_flags & XFS_MD2_INCOMPAT_EXTERNALLOG ? "":"not ",
+		incompat_flags & XFS_MD2_INCOMPAT_FULLBLOCKS ? "full":"zeroed");
+}
+
+#define MDR_IO_BUF_SIZE (8 * 1024 * 1024)
+
+static void
+dump_meta_extent(
+	FILE		*md_fp,
+	int		dev_fd,
+	char		*device,
+	void		*buf,
+	uint64_t	offset,
+	int		len)
+{
+	int		io_size;
+
+	io_size = min(len, MDR_IO_BUF_SIZE);
+
+	do {
+		if (fread(buf, io_size, 1, md_fp) != 1)
+			fatal("error reading from metadump file\n");
+		if (pwrite(dev_fd, buf, io_size, offset) < 0)
+			fatal("error writing to %s device at offset %llu: %s\n",
+				device, offset, strerror(errno));
+		len -= io_size;
+		offset += io_size;
+
+		io_size = min(len, io_size);
+	} while (len);
+}
+
+static void
+restore_v2(
+	void			*header,
+	FILE			*md_fp,
+	int			ddev_fd,
+	bool			is_data_target_file,
+	int			logdev_fd,
+	bool			is_log_target_file)
+{
+	struct xfs_sb		sb;
+	struct xfs_meta_extent	xme;
+	char			*block_buffer;
+	int64_t			bytes_read;
+	uint64_t		offset;
+	int			len;
+
+	block_buffer = malloc(MDR_IO_BUF_SIZE);
+	if (block_buffer == NULL)
+		fatal("Unable to allocate input buffer memory\n");
+
+	if (fread(&xme, sizeof(xme), 1, md_fp) != 1)
+		fatal("error reading from metadump file\n");
+
+	if (xme.xme_addr != 0 || xme.xme_len == 1)
+		fatal("Invalid superblock disk address/length\n");
+
+	len = BBTOB(be32_to_cpu(xme.xme_len));
+
+	if (fread(block_buffer, len, 1, md_fp) != 1)
+		fatal("error reading from metadump file\n");
+
+	libxfs_sb_from_disk(&sb, (struct xfs_dsb *)block_buffer);
+
+	if (sb.sb_magicnum != XFS_SB_MAGIC)
+		fatal("bad magic number for primary superblock\n");
+
+	((struct xfs_dsb *)block_buffer)->sb_inprogress = 1;
+
+	verify_device_size(ddev_fd, is_data_target_file, sb.sb_dblocks,
+			sb.sb_blocksize);
+
+	if (sb.sb_logstart == 0) {
+		ASSERT(mdrestore.external_log == true);
+		verify_device_size(logdev_fd, is_log_target_file, sb.sb_logblocks,
+				sb.sb_blocksize);
+	}
+
+	if (pwrite(ddev_fd, block_buffer, len, 0) < 0)
+		fatal("error writing primary superblock: %s\n",
+			strerror(errno));
+
+	bytes_read = len;
+
+	do {
+		char *device;
+		int fd;
+
+		if (fread(&xme, sizeof(xme), 1, md_fp) != 1) {
+			if (feof(md_fp))
+				break;
+			fatal("error reading from metadump file\n");
+		}
+
+		offset = BBTOB(be64_to_cpu(xme.xme_addr) & XME_ADDR_DADDR_MASK);
+		switch (be64_to_cpu(xme.xme_addr) & XME_ADDR_DEVICE_MASK) {
+		case XME_ADDR_DATA_DEVICE:
+			device = "data";
+			fd = ddev_fd;
+			break;
+		case XME_ADDR_LOG_DEVICE:
+			device = "log";
+			fd = logdev_fd;
+			break;
+		default:
+			fatal("Invalid device found in metadump\n");
+			break;
+		}
+
+		len = BBTOB(be32_to_cpu(xme.xme_len));
+
+		dump_meta_extent(md_fp, fd, device, block_buffer, offset, len);
+
+		bytes_read += len;
+
+		if (mdrestore.show_progress) {
+			static int64_t mb_read;
+			int64_t mb_now = bytes_read >> 20;
+
+			if (mb_now != mb_read) {
+				print_progress("%lld MB read", mb_now);
+				mb_read = mb_now;
+			}
+		}
+	} while (1);
+
+	if (mdrestore.progress_since_warning)
+		putchar('\n');
+
+	memset(block_buffer, 0, sb.sb_sectsize);
+	sb.sb_inprogress = 0;
+	libxfs_sb_to_disk((struct xfs_dsb *)block_buffer, &sb);
+	if (xfs_sb_version_hascrc(&sb)) {
+		xfs_update_cksum(block_buffer, sb.sb_sectsize,
+				offsetof(struct xfs_sb, sb_crc));
+	}
+
+	if (pwrite(ddev_fd, block_buffer, sb.sb_sectsize, 0) < 0)
+		fatal("error writing primary superblock: %s\n",
+			strerror(errno));
+
+	free(block_buffer);
+
+	return;
+}
+
+static struct mdrestore_ops mdrestore_ops_v2 = {
+	.read_header	= read_header_v2,
+	.show_info	= show_info_v2,
+	.restore	= restore_v2,
+};
+
 static void
 usage(void)
 {
@@ -276,17 +469,24 @@ main(
 	int 		argc,
 	char 		**argv)
 {
-	FILE		*src_f;
-	int		dst_fd;
-	int		c;
-	bool		is_target_file;
-	uint32_t	magic;
-	void		*header;
-	struct xfs_metablock	mb;
+	union {
+		struct xfs_metadump_header	xmh;
+		struct xfs_metablock		mb;
+	} md;
+	FILE				*src_f;
+	char				*logdev = NULL;
+	void				*header;
+	uint32_t			magic;
+	int				data_dev_fd;
+	int				log_dev_fd;
+	int				c;
+	bool				is_data_dev_file;
+	bool				is_log_dev_file;
 
 	mdrestore.show_progress = false;
 	mdrestore.show_info = false;
 	mdrestore.progress_since_warning = false;
+	mdrestore.external_log = false;
 
 	progname = basename(argv[0]);
 
@@ -332,11 +532,17 @@ main(
 	if (fread(&magic, sizeof(magic), 1, src_f) != 1)
 		fatal("Unable to read metadump magic from metadump file\n");
 
+	header = &md;
+
 	switch (be32_to_cpu(magic)) {
 	case XFS_MD_MAGIC_V1:
-		header = &mb;
 		mdrestore.mdrops = &mdrestore_ops_v1;
 		break;
+
+	case XFS_MD_MAGIC_V2:
+		mdrestore.mdrops = &mdrestore_ops_v2;
+		break;
+
 	default:
 		fatal("specified file is not a metadata dump\n");
 		break;
@@ -353,12 +559,21 @@ main(
 
 	optind++;
 
-	/* check and open target */
-	dst_fd = open_device(argv[optind], &is_target_file);
+	/* check and open data device */
+	data_dev_fd = open_device(argv[optind], &is_data_dev_file);
+
+	log_dev_fd = -1;
+	if (mdrestore.external_log)
+		/* check and open log device */
+		log_dev_fd = open_device(logdev, &is_log_dev_file);
+
+	mdrestore.mdrops->restore(header, src_f, data_dev_fd, is_data_dev_file,
+				log_dev_fd, is_log_dev_file);
 
-	mdrestore.mdrops->restore(header, src_f, dst_fd, is_target_file);
+	close(data_dev_fd);
+	if (mdrestore.external_log)
+		close(log_dev_fd);
 
-	close(dst_fd);
 	if (src_f != stdin)
 		fclose(src_f);
 
-- 
2.39.1