mdrestore: Add open_device(), read_header() and show_info() functions

This commit moves functionality associated with opening the target device,
reading metadump header information and printing information about the
metadump into their respective functions. There are no functional changes made
by this commit.

Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

1 files changed, 84 insertions, 57 deletions

diff --git a/mdrestore/xfs_mdrestore.c b/mdrestore/xfs_mdrestore.c
index ffa8274f39..d67a06298f 100644
--- a/mdrestore/xfs_mdrestore.c
+++ b/mdrestore/xfs_mdrestore.c
@@ -6,6 +6,7 @@
 
 #include "libxfs.h"
 #include "xfs_metadump.h"
+#include <libfrog/platform.h>
 
 static struct mdrestore {
 	bool	show_progress;
@@ -40,8 +41,71 @@ print_progress(const char *fmt, ...)
 	mdrestore.progress_since_warning = true;
 }
 
+static int
+open_device(
+	char		*path,
+	bool		*is_file)
+{
+	struct stat	statbuf;
+	int		open_flags;
+	int		fd;
+
+	open_flags = O_RDWR;
+	*is_file = false;
+
+	if (stat(path, &statbuf) < 0)  {
+		/* ok, assume it's a file and create it */
+		open_flags |= O_CREAT;
+		*is_file = true;
+	} else if (S_ISREG(statbuf.st_mode))  {
+		open_flags |= O_TRUNC;
+		*is_file = true;
+	} else if (platform_check_ismounted(path, NULL, &statbuf, 0)) {
+		/*
+		 * check to make sure a filesystem isn't mounted on the device
+		 */
+		fatal("a filesystem is mounted on target device \"%s\","
+				" cannot restore to a mounted filesystem.\n",
+				path);
+	}
+
+	fd = open(path, open_flags, 0644);
+	if (fd < 0)
+		fatal("couldn't open \"%s\"\n", path);
+
+	return fd;
+}
+
+static void
+read_header(
+	struct xfs_metablock	*mb,
+	FILE			*md_fp)
+{
+	mb->mb_magic = cpu_to_be32(XFS_MD_MAGIC_V1);
+
+	if (fread((uint8_t *)mb + sizeof(mb->mb_magic),
+			sizeof(*mb) - sizeof(mb->mb_magic), 1, md_fp) != 1)
+		fatal("error reading from metadump file\n");
+}
+
+static void
+show_info(
+	struct xfs_metablock	*mb,
+	const char		*md_file)
+{
+	if (mb->mb_info & XFS_METADUMP_INFO_FLAGS) {
+		printf("%s: %sobfuscated, %s log, %s metadata blocks\n",
+			md_file,
+			mb->mb_info & XFS_METADUMP_OBFUSCATED ? "":"not ",
+			mb->mb_info & XFS_METADUMP_DIRTYLOG ? "dirty":"clean",
+			mb->mb_info & XFS_METADUMP_FULLBLOCKS ? "full":"zeroed");
+	} else {
+		printf("%s: no informational flags present\n", md_file);
+	}
+}
+
 /*
- * perform_restore() -- do the actual work to restore the metadump
+ * restore() -- do the actual work to restore the metadump
  *
  * @src_f: A FILE pointer to the source metadump
  * @dst_fd: the file descriptor for the target file
@@ -51,9 +115,9 @@ print_progress(const char *fmt, ...)
  * src_f should be positioned just past a read the previously validated metablock
  */
 static void
-perform_restore(
-	FILE			*src_f,
-	int			dst_fd,
+restore(
+	FILE			*md_fp,
+	int			ddev_fd,
 	int			is_target_file,
 	const struct xfs_metablock	*mbp)
 {
@@ -81,14 +145,15 @@ perform_restore(
 	block_index = (__be64 *)((char *)metablock + sizeof(xfs_metablock_t));
 	block_buffer = (char *)metablock + block_size;
 
-	if (fread(block_index, block_size - sizeof(struct xfs_metablock), 1, src_f) != 1)
+	if (fread(block_index, block_size - sizeof(struct xfs_metablock), 1,
+			md_fp) != 1)
 		fatal("error reading from metadump file\n");
 
 	if (block_index[0] != 0)
 		fatal("first block is not the primary superblock\n");
 
 
-	if (fread(block_buffer, mb_count << mbp->mb_blocklog, 1, src_f) != 1)
+	if (fread(block_buffer, mb_count << mbp->mb_blocklog, 1, md_fp) != 1)
 		fatal("error reading from metadump file\n");
 
 	libxfs_sb_from_disk(&sb, (struct xfs_dsb *)block_buffer);
@@ -111,7 +176,7 @@ perform_restore(
 	if (is_target_file)  {
 		/* ensure regular files are correctly sized */
 
-		if (ftruncate(dst_fd, sb.sb_dblocks * sb.sb_blocksize))
+		if (ftruncate(ddev_fd, sb.sb_dblocks * sb.sb_blocksize))
 			fatal("cannot set filesystem image size: %s\n",
 				strerror(errno));
 	} else  {
@@ -121,7 +186,7 @@ perform_restore(
 		off64_t		off;
 
 		off = sb.sb_dblocks * sb.sb_blocksize - sizeof(lb);
-		if (pwrite(dst_fd, lb, sizeof(lb), off) < 0)
+		if (pwrite(ddev_fd, lb, sizeof(lb), off) < 0)
 			fatal("failed to write last block, is target too "
 				"small? (error: %s)\n", strerror(errno));
 	}
@@ -134,7 +199,7 @@ perform_restore(
 			print_progress("%lld MB read", bytes_read >> 20);
 
 		for (cur_index = 0; cur_index < mb_count; cur_index++) {
-			if (pwrite(dst_fd, &block_buffer[cur_index <<
+			if (pwrite(ddev_fd, &block_buffer[cur_index <<
 					mbp->mb_blocklog], block_size,
 					be64_to_cpu(block_index[cur_index]) <<
 						BBSHIFT) < 0)
@@ -145,7 +210,7 @@ perform_restore(
 		if (mb_count < max_indices)
 			break;
 
-		if (fread(metablock, block_size, 1, src_f) != 1)
+		if (fread(metablock, block_size, 1, md_fp) != 1)
 			fatal("error reading from metadump file\n");
 
 		mb_count = be16_to_cpu(metablock->mb_count);
@@ -155,7 +220,7 @@ perform_restore(
 			fatal("bad block count: %u\n", mb_count);
 
 		if (fread(block_buffer, mb_count << mbp->mb_blocklog,
-								1, src_f) != 1)
+				1, md_fp) != 1)
 			fatal("error reading from metadump file\n");
 
 		bytes_read += block_size + (mb_count << mbp->mb_blocklog);
@@ -172,7 +237,7 @@ perform_restore(
 				 offsetof(struct xfs_sb, sb_crc));
 	}
 
-	if (pwrite(dst_fd, block_buffer, sb.sb_sectsize, 0) < 0)
+	if (pwrite(ddev_fd, block_buffer, sb.sb_sectsize, 0) < 0)
 		fatal("error writing primary superblock: %s\n", strerror(errno));
 
 	free(metablock);
@@ -185,8 +250,6 @@ usage(void)
 	exit(1);
 }
 
-extern int	platform_check_ismounted(char *, char *, struct stat *, int);
-
 int
 main(
 	int 		argc,
@@ -195,9 +258,7 @@ main(
 	FILE		*src_f;
 	int		dst_fd;
 	int		c;
-	int		open_flags;
-	struct stat	statbuf;
-	int		is_target_file;
+	bool		is_target_file;
 	uint32_t	magic;
 	struct xfs_metablock	mb;
 
@@ -231,8 +292,8 @@ main(
 		usage();
 
 	/*
-	 * open source and test if this really is a dump. The first metadump block
-	 * will be passed to perform_restore() which will continue to read the
+	 * open source and test if this really is a dump. The first metadump
+	 * block will be passed to restore() which will continue to read the
 	 * file from this point. This avoids rewind the stream, which causes
 	 * restore to fail when source was being read from stdin.
  	 */
@@ -251,11 +312,7 @@ main(
 
 	switch (be32_to_cpu(magic)) {
 	case XFS_MD_MAGIC_V1:
-		mb.mb_magic = cpu_to_be32(XFS_MD_MAGIC_V1);
-		if (fread((uint8_t *)&mb + sizeof(mb.mb_magic),
-				sizeof(mb) - sizeof(mb.mb_magic), 1,
-				src_f) != 1)
-			fatal("error reading from metadump file\n");
+		read_header(&mb, src_f);
 		break;
 	default:
 		fatal("specified file is not a metadata dump\n");
@@ -263,16 +320,7 @@ main(
 	}
 
 	if (mdrestore.show_info) {
-		if (mb.mb_info & XFS_METADUMP_INFO_FLAGS) {
-			printf("%s: %sobfuscated, %s log, %s metadata blocks\n",
-			argv[optind],
-			mb.mb_info & XFS_METADUMP_OBFUSCATED ? "":"not ",
-			mb.mb_info & XFS_METADUMP_DIRTYLOG ? "dirty":"clean",
-			mb.mb_info & XFS_METADUMP_FULLBLOCKS ? "full":"zeroed");
-		} else {
-			printf("%s: no informational flags present\n",
-				argv[optind]);
-		}
+		show_info(&mb, argv[optind]);
 
 		if (argc - optind == 1)
 			exit(0);
@@ -281,30 +329,9 @@ main(
 	optind++;
 
 	/* check and open target */
-	open_flags = O_RDWR;
-	is_target_file = 0;
-	if (stat(argv[optind], &statbuf) < 0)  {
-		/* ok, assume it's a file and create it */
-		open_flags |= O_CREAT;
-		is_target_file = 1;
-	} else if (S_ISREG(statbuf.st_mode))  {
-		open_flags |= O_TRUNC;
-		is_target_file = 1;
-	} else  {
-		/*
-		 * check to make sure a filesystem isn't mounted on the device
-		 */
-		if (platform_check_ismounted(argv[optind], NULL, &statbuf, 0))
-			fatal("a filesystem is mounted on target device \"%s\","
-				" cannot restore to a mounted filesystem.\n",
-				argv[optind]);
-	}
-
-	dst_fd = open(argv[optind], open_flags, 0644);
-	if (dst_fd < 0)
-		fatal("couldn't open target \"%s\"\n", argv[optind]);
+	dst_fd = open_device(argv[optind], &is_target_file);
 
-	perform_restore(src_f, dst_fd, is_target_file, &mb);
+	restore(src_f, dst_fd, is_target_file, &mb);
 
 	close(dst_fd);
 	if (src_f != stdin)