fdisk: use context as a parameter

This program heavily uses global variables, which isn't very elegant and can
lead to nasty bugs. Modify functions that use fdisk's context current features
(descriptor and path), to receive the context as a parameter instead of
globally. This includes DOS, SUN, SGI and BSD label code. Another benefit that
comes with this is that as the API grows all the information regarding fdisk
will be accessible from this structure so we can reduce even more global
variables and simply code.

This patch passed:
 - building
 - regression tests
 - local dos/sun/bsd partition changes

Signed-off-by: Davidlohr Bueso <dave@gnu.org>

1 files changed, 53 insertions, 51 deletions

diff --git a/fdisk/fdisk.c b/fdisk/fdisk.c
index 084253dbc..b304fe320 100644
--- a/fdisk/fdisk.c
+++ b/fdisk/fdisk.c
@@ -55,7 +55,6 @@
 
 unsigned char *MBRbuffer;
 int MBRbuffer_changed;
-struct fdisk_context *cxt = NULL;
 
 #define hex_val(c)	({ \
 				char _c = (c); \
@@ -180,7 +179,7 @@ static void __attribute__ ((__noreturn__)) usage(FILE *out)
 	exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
 }
 
-void fatal(enum failure why)
+void fatal(struct fdisk_context *cxt, enum failure why)
 {
 	close(cxt->dev_fd);
 	switch (why) {
@@ -453,7 +452,7 @@ void warn_alignment(void)
 }
 
 static void
-get_topology(int fd) {
+get_topology(struct fdisk_context *cxt) {
 	int arg;
 #ifdef HAVE_LIBBLKID
 	blkid_probe pr;
@@ -593,15 +592,15 @@ update_sector_offset(void)
 }
 
 void
-get_geometry(int fd, struct geom *g) {
+get_geometry(struct fdisk_context *cxt, struct geom *g) {
 	unsigned long long llcyls, nsects = 0;
 	unsigned int kern_heads = 0, kern_sectors = 0;
 
-	get_topology(fd);
+	get_topology(cxt);
 	heads = cylinders = sectors = 0;
 	pt_heads = pt_sectors = 0;
 
-	blkdev_get_geometry(fd, &kern_heads, &kern_sectors);
+	blkdev_get_geometry(cxt->dev_fd, &kern_heads, &kern_sectors);
 	get_partition_table_geometry();
 
 	heads = user_heads ? user_heads :
@@ -612,7 +611,7 @@ get_geometry(int fd, struct geom *g) {
 		kern_sectors ? kern_sectors : 63;
 
 	/* get number of 512-byte sectors, and convert it the real sectors */
-	if (blkdev_get_sectors(fd, &nsects) == 0)
+	if (blkdev_get_sectors(cxt->dev_fd, &nsects) == 0)
 		total_number_of_sectors = (nsects / (sector_size >> 9));
 
 	update_sector_offset();
@@ -658,7 +657,7 @@ void zeroize_mbr_buffer(void)
  *    0: found or created label
  *    1: I/O error
  */
-static int get_boot(int try_only) {
+static int get_boot(struct fdisk_context *cxt, int try_only) {
 
 	disklabel = ANY_LABEL;
 	memset(MBRbuffer, 0, 512);
@@ -666,17 +665,17 @@ static int get_boot(int try_only) {
 	if (512 != read(cxt->dev_fd, MBRbuffer, 512)) {
 		if (try_only)
 			return 1;
-		fatal(unable_to_read);
+		fatal(cxt, unable_to_read);
 	}
 
-	get_geometry(cxt->dev_fd, NULL);
+	get_geometry(cxt, NULL);
 	update_units();
 
-	if (!check_dos_label())
+	if (!check_dos_label(cxt))
 		if (check_sun_label() || check_sgi_label() || check_aix_label() || check_mac_label())
 			return 0;
 
-	if (check_osf_label()) {
+	if (check_osf_label(cxt)) {
 		/* intialize partitions for BSD as well */
 		dos_init();
 		if (!valid_part_table_flag(MBRbuffer)) {
@@ -695,7 +694,7 @@ static int get_boot(int try_only) {
 		fprintf(stderr,
 			_("Device does not contain a recognized partition table\n"));
 #ifdef __sparc__
-		create_sunlabel();
+		create_sunlabel(cxt);
 #else
 		create_doslabel();
 #endif
@@ -1214,7 +1213,7 @@ check_alignment(unsigned long long lba, int partition)
 }
 
 static void
-list_disk_geometry(void) {
+list_disk_geometry(struct fdisk_context *cxt) {
 	unsigned long long bytes = total_number_of_sectors * sector_size;
 	long megabytes = bytes/1000000;
 
@@ -1382,25 +1381,25 @@ fix_partition_table_order(void) {
 }
 
 static void
-list_table(int xtra) {
+list_table(struct fdisk_context *cxt, int xtra) {
 	struct partition *p;
 	char *type;
 	int i, w;
 
 	if (disklabel == SUN_LABEL) {
-		sun_list_table(xtra);
+		sun_list_table(cxt, xtra);
 		return;
 	}
 
 	if (disklabel == SGI_LABEL) {
-		sgi_list_table(xtra);
+		sgi_list_table(cxt, xtra);
 		return;
 	}
 
-	list_disk_geometry();
+	list_disk_geometry(cxt);
 
 	if (disklabel == OSF_LABEL) {
-		xbsd_print_disklabel(xtra);
+		xbsd_print_disklabel(cxt, xtra);
 		return;
 	}
 
@@ -1462,7 +1461,7 @@ list_table(int xtra) {
 }
 
 static void
-x_list_table(int extend) {
+x_list_table(struct fdisk_context *cxt, int extend) {
 	struct pte *pe;
 	struct partition *p;
 	int i;
@@ -1656,14 +1655,14 @@ static void new_partition(void)
 }
 
 static void
-write_table(void) {
+write_table(struct fdisk_context *cxt) {
 	int i;
 
 	if (disklabel == DOS_LABEL)
-		dos_write_table();
+		dos_write_table(cxt);
 	else if (disklabel == SGI_LABEL)
 		/* no test on change? the printf below might be mistaken */
-		sgi_write_table();
+		sgi_write_table(cxt);
 	else if (disklabel == SUN_LABEL) {
 		int needw = 0;
 
@@ -1671,15 +1670,15 @@ write_table(void) {
 			if (ptes[i].changed)
 				needw = 1;
 		if (needw)
-			sun_write_table();
+			sun_write_table(cxt);
 	}
 
 	printf(_("The partition table has been altered!\n\n"));
-	reread_partition_table(1);
+	reread_partition_table(cxt, 1);
 }
 
 void
-reread_partition_table(int leave) {
+reread_partition_table(struct fdisk_context *cxt, int leave) {
 	int i;
 	struct stat statbuf;
 
@@ -1740,10 +1739,10 @@ print_buffer(unsigned char pbuffer[]) {
 }
 
 static void
-print_raw(void) {
+print_raw(char *dev) {
 	int i;
 
-	printf(_("Device: %s\n"), cxt->dev_path);
+	printf(_("Device: %s\n"), dev);
 	if (disklabel == SUN_LABEL || disklabel == SGI_LABEL)
 		print_buffer(MBRbuffer);
 	else for (i = 3; i < partitions; i++)
@@ -1807,7 +1806,7 @@ static void __attribute__ ((__noreturn__)) handle_quit(struct fdisk_context *cxt
 }
 
 static void
-expert_command_prompt(void)
+expert_command_prompt(struct fdisk_context *cxt)
 {
 	char c;
 
@@ -1831,7 +1830,7 @@ expert_command_prompt(void)
 				sun_set_ncyl(cylinders);
 			break;
 		case 'd':
-			print_raw();
+			print_raw(cxt->dev_path);
 			break;
 		case 'e':
 			if (disklabel == SGI_LABEL)
@@ -1840,14 +1839,14 @@ expert_command_prompt(void)
 				sun_set_xcyl();
 			else
 			if (disklabel == DOS_LABEL)
-				x_list_table(1);
+				x_list_table(cxt, 1);
 			break;
 		case 'f':
 			if (disklabel == DOS_LABEL)
 				fix_partition_table_order();
 			break;
 		case 'g':
-			create_sgilabel();
+			create_sgilabel(cxt);
 			break;
 		case 'h':
 			user_heads = heads = read_int(1, heads, 256, 0,
@@ -1866,9 +1865,9 @@ expert_command_prompt(void)
 			break;
 		case 'p':
 			if (disklabel == SUN_LABEL)
-				list_table(1);
+				list_table(cxt, 1);
 			else
-				x_list_table(0);
+				x_list_table(cxt, 0);
 			break;
 		case 'q':
 			handle_quit(cxt);
@@ -1888,7 +1887,7 @@ expert_command_prompt(void)
 			verify();
 			break;
 		case 'w':
-			write_table(); 	/* does not return */
+			write_table(cxt); 	/* does not return */
 			break;
 		case 'y':
 			if (disklabel == SUN_LABEL)
@@ -1927,19 +1926,19 @@ print_partition_table_from_option(char *device)
 {
 	int gb;
 
-	cxt = fdisk_new_context_from_filename(device, 1);	/* read-only */
+	struct fdisk_context *cxt = fdisk_new_context_from_filename(device, 1);	/* read-only */
 	if (!cxt)
 		err(EXIT_FAILURE, _("unable to open %s"), device);
 
 	gpt_warning(device);
-	gb = get_boot(1);
+	gb = get_boot(cxt, 1);
 	if (gb < 0) { /* no DOS signature */
-		list_disk_geometry();
+		list_disk_geometry(cxt);
 		if (disklabel != AIX_LABEL && disklabel != MAC_LABEL)
-			btrydev(device);
+			btrydev(cxt);
 	}
 	else if (!gb)
-		list_table(0);
+		list_table(cxt, 0);
 	fdisk_free_context(cxt);
 	cxt = NULL;
 }
@@ -1993,7 +1992,7 @@ static void print_welcome(void)
 	fflush(stdout);
 }
 
-static void command_prompt(void)
+static void command_prompt(struct fdisk_context *cxt)
 {
 	int c;
 
@@ -2003,7 +2002,7 @@ static void command_prompt(void)
 		printf(_("Detected an OSF/1 disklabel on %s, entering "
 			 "disklabel mode.\n"),
 		       cxt->dev_path);
-		bsd_command_prompt();
+		bsd_command_prompt(cxt);
 		/* If we return we may want to make an empty DOS label? */
 		disklabel = DOS_LABEL;
 	}
@@ -2029,7 +2028,7 @@ static void command_prompt(void)
 				sgi_set_bootfile();
 			else if (disklabel == DOS_LABEL) {
 				disklabel = OSF_LABEL;
-				bsd_command_prompt();
+				bsd_command_prompt(cxt);
 				disklabel = DOS_LABEL;
 			} else
 				unknown_command(c);
@@ -2068,12 +2067,12 @@ static void command_prompt(void)
 			create_doslabel();
 			break;
 		case 'p':
-			list_table(0);
+			list_table(cxt, 0);
 			break;
 		case 'q':
 			handle_quit(cxt);
 		case 's':
-			create_sunlabel();
+			create_sunlabel(cxt);
 			break;
 		case 't':
 			change_sysid();
@@ -2085,10 +2084,10 @@ static void command_prompt(void)
 			verify();
 			break;
 		case 'w':
-			write_table(); 		/* does not return */
+			write_table(cxt); 		/* does not return */
 			break;
 		case 'x':
-			expert_command_prompt();
+			expert_command_prompt(cxt);
 			break;
 		default:
 			unknown_command(c);
@@ -2104,8 +2103,10 @@ static unsigned long long get_dev_blocks(char *dev)
 
 	if ((fd = open(dev, O_RDONLY)) < 0)
 		err(EXIT_FAILURE, _("unable to open %s"), dev);
-	if (blkdev_get_sectors(fd, &size) == -1)
-		fatal(ioctl_error);
+	if (blkdev_get_sectors(fd, &size) == -1) {
+		close(fd);
+		err(EXIT_FAILURE, _("BLKGETSIZE ioctl failed on %s"), dev);
+	}
 	close(fd);
 	return size/2;
 }
@@ -2113,6 +2114,7 @@ static unsigned long long get_dev_blocks(char *dev)
 int main(int argc, char **argv)
 {
 	int c, optl = 0, opts = 0;
+	struct fdisk_context *cxt = NULL;
 
 	setlocale(LC_ALL, "");
 	bindtextdomain(PACKAGE, LOCALEDIR);
@@ -2223,9 +2225,9 @@ int main(int argc, char **argv)
 	print_welcome();
 
 	gpt_warning(cxt->dev_path);
-	get_boot(0);
+	get_boot(cxt, 0);
 
-	command_prompt();
+	command_prompt(cxt);
 
 	return 0;
 }