fsck: introduce the option "b" to repair the main boot sector

If the option "b" is given, try to recover the main boot sector even if exfat is not found. otherwise warn it and just exit. Signed-off-by: Hyunchul Lee <[email protected]>
namjaejeon · Dec 9, 2021 · d58057b · d58057b
1 parent 9c164ba
commit d58057b
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Showing 3 changed files with 22 additions and 1 deletion.
diff --git a/fsck/fsck.c b/fsck/fsck.c
@@ -77,6 +77,7 @@ static struct option opts[] = {
 	{"verbose",	no_argument,	NULL,	'v' },
 	{"help",	no_argument,	NULL,	'h' },
 	{"?",		no_argument,	NULL,	'?' },
+	{"ignore-bad-fs",	no_argument,	NULL,	'b' },
 	{NULL,		0,		NULL,	 0  }
 };
 
@@ -88,6 +89,7 @@ static void usage(char *name)
 	fprintf(stderr, "\t-n | --repair-no     No repair\n");
 	fprintf(stderr, "\t-p | --repair-auto   Repair automatically\n");
 	fprintf(stderr, "\t-a                   Repair automatically\n");
+	fprintf(stderr, "\t-b | --ignore-bad-fs Try to recover even if exfat is not found\n");
 	fprintf(stderr, "\t-V | --version       Show version\n");
 	fprintf(stderr, "\t-v | --verbose       Print debug\n");
 	fprintf(stderr, "\t-h | --help          Show help\n");
@@ -796,9 +798,17 @@ static int exfat_boot_region_check(struct exfat *exfat, struct pbr **bs)
 	if (exfat_read(exfat->blk_dev->dev_fd, boot_sect,
 		       sizeof(*boot_sect), 0) != (ssize_t)sizeof(*boot_sect)) {
 		exfat_err("failed to read Main boot sector\n");
+		free(boot_sect);
 		return -EIO;
 	}
 
+	if (memcmp(boot_sect->bpb.oem_name, "EXFAT   ", 8) != 0 &&
+	    !(exfat->options & FSCK_OPTS_IGNORE_BAD_FS_NAME)) {
+		exfat_err("Bad fs_name in boot sector, which does not describe a valid exfat filesystem\n");
+		free(boot_sect);
+		return -ENOTSUP;
+	}
+
 	sect_size = 1 << boot_sect->bsx.sect_size_bits;
 	free(boot_sect);
 
@@ -1530,7 +1540,7 @@ int main(int argc, char * const argv[])
 		exfat_err("failed to init locale/codeset\n");
 
 	opterr = 0;
-	while ((c = getopt_long(argc, argv, "arynpVvh", opts, NULL)) != EOF) {
+	while ((c = getopt_long(argc, argv, "arynpbVvh", opts, NULL)) != EOF) {
 		switch (c) {
 		case 'n':
 			if (ui.options & FSCK_OPTS_REPAIR_ALL)
@@ -1553,6 +1563,9 @@ int main(int argc, char * const argv[])
 				usage(argv[0]);
 			ui.options |= FSCK_OPTS_REPAIR_AUTO;
 			break;
+		case 'b':
+			ui.options |= FSCK_OPTS_IGNORE_BAD_FS_NAME;
+			break;
 		case 'V':
 			version_only = true;
 			break;
@@ -1576,6 +1589,8 @@ int main(int argc, char * const argv[])
 	if (ui.options & FSCK_OPTS_REPAIR_WRITE)
 		ui.ei.writeable = true;
 	else {
+		if (ui.options & FSCK_OPTS_IGNORE_BAD_FS_NAME)
+			usage(argv[0]);
 		ui.options |= FSCK_OPTS_REPAIR_NO;
 		ui.ei.writeable = false;
 	}

diff --git a/fsck/fsck.h b/fsck/fsck.h
@@ -54,6 +54,7 @@ enum fsck_ui_options {
 	FSCK_OPTS_REPAIR_AUTO	= 0x08,
 	FSCK_OPTS_REPAIR_WRITE	= 0x0b,
 	FSCK_OPTS_REPAIR_ALL	= 0x0f,
+	FSCK_OPTS_IGNORE_BAD_FS_NAME	= 0x10,
 };
 
 struct exfat {

diff --git a/manpages/fsck.exfat.8 b/manpages/fsck.exfat.8
@@ -14,6 +14,8 @@ fsck.exfat \- check an exFAT filesystem
 ] [
 .B \-y
 ] [
+.B \-b
+] [
 .B \-v
 ]
 .I device
@@ -46,6 +48,9 @@ Prints the version number and exits.
 .TP
 .B \-y
 Repair the filesystem answering yes to all questions.
+.TP
+.B \-b
+Try to repair the filesystem even if the exFAT filesystem is not found.
 .SH SEE ALSO
 .BR fsck (8),
 .BR fstab (5),