libfdisk: make it possible to reset device properties

 - remember user C/H/S and sector size
 - reset all device properties before create a new label (maybe the
   old setting has been affected by previous on-disk label)
 - always apply user setting after the reset
 - improve topology/geometry debug messages

Note that for fdisk "user C/H/S and sector size" means on command line
specified values. If you override the setting by c/h/s commands in
expert menu then the setting is applied to the current disk label
only. If you create a new disk label (e.g change MBR to GPT) then
fdisk will use the original setting.

Signed-off-by: Karel Zak <kzak@redhat.com>

6 files changed, 182 insertions, 81 deletions

diff --git a/fdisks/fdisk.c b/fdisks/fdisk.c
index 96cd71958..12700ee6e 100644
--- a/fdisks/fdisk.c
+++ b/fdisks/fdisk.c
@@ -58,9 +58,6 @@ char	*line_ptr,			/* interactive input */
 
 int	nowarn = 0;			/* no warnings for fdisk -l/-s */
 
-/* when C/H/S specified on command line */
-static unsigned int user_cylinders, user_heads, user_sectors;
-
 void toggle_units(struct fdisk_context *cxt)
 {
 	fdisk_context_set_unit(cxt,
@@ -796,19 +793,13 @@ static int is_ide_cdrom_or_tape(char *device)
 }
 
 /* Print disk geometry and partition table of a specified device (-l option) */
-static void print_partition_table_from_option(struct fdisk_context *cxt,
-				char *device, unsigned long sector_size)
+static void print_partition_table_from_option(
+			struct fdisk_context *cxt,
+			char *device)
 {
 	if (fdisk_context_assign_device(cxt, device, 1) != 0)	/* read-only */
 		err(EXIT_FAILURE, _("cannot open %s"), device);
 
-	if (sector_size) /* passed -b option, override autodiscovery */
-		fdisk_override_sector_size(cxt, sector_size);
-
-	if (user_cylinders || user_heads || user_sectors)
-		fdisk_override_geometry(cxt, user_cylinders,
-					user_heads, user_sectors);
-
 	if (fdisk_dev_has_disklabel(cxt))
 		list_table(cxt, 0);
 	else
@@ -820,8 +811,7 @@ static void print_partition_table_from_option(struct fdisk_context *cxt,
  * try all things in /proc/partitions that look like a full disk
  */
 static void
-print_all_partition_table_from_option(struct fdisk_context *cxt,
-				      unsigned long sector_size)
+print_all_partition_table_from_option(struct fdisk_context *cxt)
 {
 	FILE *procpt;
 	char line[128 + 1], ptname[128 + 1], devname[256];
@@ -843,7 +833,7 @@ print_all_partition_table_from_option(struct fdisk_context *cxt,
 			char *cn = canonicalize_path(devname);
 			if (cn) {
 				if (!is_ide_cdrom_or_tape(cn))
-					print_partition_table_from_option(cxt, cn, sector_size);
+					print_partition_table_from_option(cxt, cn);
 				free(cn);
 			}
 		}
@@ -1029,9 +1019,13 @@ int main(int argc, char **argv)
 			if (sector_size != 512 && sector_size != 1024 &&
 			    sector_size != 2048 && sector_size != 4096)
 				usage(stderr);
+			fdisk_save_user_sector_size(cxt, sector_size, sector_size);
 			break;
 		case 'C':
-			user_cylinders =  strtou32_or_err(optarg, _("invalid cylinders argument"));
+			fdisk_save_user_geometry(cxt,
+				strtou32_or_err(optarg,
+						_("invalid cylinders argument")),
+				0, 0);
 			break;
 		case 'c':
 			if (optarg) {
@@ -1050,14 +1044,15 @@ int main(int argc, char **argv)
 			/* use default if no optarg specified */
 			break;
 		case 'H':
-			user_heads = strtou32_or_err(optarg, _("invalid heads argument"));
-			if (user_heads > 256)
-				user_heads = 0;
+			fdisk_save_user_geometry(cxt, 0,
+				strtou32_or_err(optarg,
+						_("invalid heads argument")),
+				0);
 			break;
 		case 'S':
-			user_sectors =  strtou32_or_err(optarg, _("invalid sectors argument"));
-			if (user_sectors >= 64)
-				user_sectors = 0;
+			fdisk_save_user_geometry(cxt, 0, 0,
+				strtou32_or_err(optarg,
+					_("invalid sectors argument")));
 			break;
 		case 'l':
 			optl = 1;
@@ -1092,9 +1087,9 @@ int main(int argc, char **argv)
 		if (argc > optind) {
 			int k;
 			for (k = optind; k < argc; k++)
-				print_partition_table_from_option(cxt, argv[k], sector_size);
+				print_partition_table_from_option(cxt, argv[k]);
 		} else
-			print_all_partition_table_from_option(cxt, sector_size);
+			print_all_partition_table_from_option(cxt);
 		exit(EXIT_SUCCESS);
 	}
 
@@ -1119,13 +1114,6 @@ int main(int argc, char **argv)
 	if (fdisk_context_assign_device(cxt, argv[optind], 0) != 0)
 		err(EXIT_FAILURE, _("cannot open %s"), argv[optind]);
 
-	if (sector_size)	/* passed -b option, override autodiscovery */
-		fdisk_override_sector_size(cxt, sector_size);
-
-	if (user_cylinders || user_heads || user_sectors)
-		fdisk_override_geometry(cxt, user_cylinders,
-						user_heads, user_sectors);
-
 	print_welcome();
 
 	if (!fdisk_dev_has_disklabel(cxt)) {
diff --git a/libfdisk/src/alignment.c b/libfdisk/src/alignment.c
index b4d3ee01d..9e7d33b67 100644
--- a/libfdisk/src/alignment.c
+++ b/libfdisk/src/alignment.c
@@ -74,6 +74,10 @@ sector_t fdisk_align_lba(struct fdisk_context *cxt, sector_t lba, int direction)
 		}
 	}
 
+	if (lba != res)
+		DBG(TOPOLOGY, dbgprint("LBA %ju -aligned-to-> %ju",
+				(uintmax_t) lba,
+				(uintmax_t) res));
 	return res;
 }
 
@@ -114,30 +118,6 @@ static unsigned long get_sector_size(int fd)
 	return DEFAULT_SECTOR_SIZE;
 }
 
-/**
- * fdisk_override_sector_size:
- * @cxt: fdisk context
- * @s: required sector size
- *
- * Overwrites logical and physical sector size. Note that the default sector
- * size is discovered by fdisk_new_context_from_device() from device topology.
- *
- * Don't use this function, rely on the default behavioer is more safe.
- *
- * Returns: 0 on success, < 0 on error.
- */
-int fdisk_override_sector_size(struct fdisk_context *cxt, sector_t s)
-{
-	if (!cxt)
-		return -EINVAL;
-
-	cxt->phy_sector_size = cxt->sector_size = s;
-	cxt->min_io_size = cxt->io_size = s;
-
-	fdisk_reset_alignment(cxt);
-	return 0;
-}
-
 static void recount_geometry(struct fdisk_context *cxt)
 {
 	cxt->geom.cylinders = cxt->total_sectors /
@@ -151,7 +131,8 @@ static void recount_geometry(struct fdisk_context *cxt)
  * @heads: user specified heads
  * @sectors: user specified sectors
  *
- * Overrides autodiscovery and apply user specified geometry.
+ * Overrides autodiscovery and apply user specified geometry. The function
+ * fdisk_reset_device_properties() restores the original setting.
  *
  * Returns: 0 on success, < 0 on error.
  */
@@ -173,6 +154,118 @@ int fdisk_override_geometry(struct fdisk_context *cxt,
 		recount_geometry(cxt);
 
 	fdisk_reset_alignment(cxt);
+
+	DBG(GEOMETRY, dbgprint("override C/H/S: %u/%u/%u",
+		(unsigned) cxt->geom.cylinders,
+		(unsigned) cxt->geom.heads,
+		(unsigned) cxt->geom.sectors));
+
+	return 0;
+}
+
+int fdisk_save_user_geometry(struct fdisk_context *cxt,
+			    unsigned int cylinders,
+			    unsigned int heads,
+			    unsigned int sectors)
+{
+	if (!cxt)
+		return -EINVAL;
+
+	cxt->user_geom.heads = heads > 256 ? 0 : heads;
+	cxt->user_geom.sectors = sectors >= 64 ? 0 : sectors;
+	cxt->user_geom.cylinders = cylinders;
+
+	DBG(GEOMETRY, dbgprint("user C/H/S: %u/%u/%u",
+				cylinders, heads, sectors));
+
+	return 0;
+}
+
+int fdisk_save_user_sector_size(struct fdisk_context *cxt,
+				unsigned int phy,
+				unsigned int log)
+{
+	if (!cxt)
+		return -EINVAL;
+
+	DBG(TOPOLOGY, dbgprint("user phy/log sector size: %u/%u", phy, log));
+
+	cxt->user_pyh_sector = phy;
+	cxt->user_log_sector = log;
+
+	return 0;
+}
+
+int fdisk_apply_user_device_properties(struct fdisk_context *cxt)
+{
+	if (!cxt)
+		return -EINVAL;
+
+	DBG(TOPOLOGY, dbgprint("appling user device properties"));
+
+	if (cxt->user_pyh_sector)
+		cxt->phy_sector_size = cxt->user_pyh_sector;
+	if (cxt->user_log_sector)
+		cxt->sector_size = cxt->min_io_size =
+			cxt->io_size = cxt->user_log_sector;
+
+	if (cxt->user_geom.heads)
+		cxt->geom.heads = cxt->user_geom.heads;
+	if (cxt->user_geom.sectors)
+		cxt->geom.sectors = cxt->user_geom.sectors;
+	if (cxt->user_geom.cylinders)
+		cxt->geom.cylinders = cxt->user_geom.cylinders;
+	else if (cxt->user_geom.heads || cxt->user_geom.sectors)
+		recount_geometry(cxt);
+
+	fdisk_reset_alignment(cxt);
+
+	DBG(GEOMETRY, dbgprint("new C/H/S: %u/%u/%u",
+		(unsigned) cxt->geom.cylinders,
+		(unsigned) cxt->geom.heads,
+		(unsigned) cxt->geom.sectors));
+	DBG(TOPOLOGY, dbgprint("new log/phy sector size: %u/%u",
+		(unsigned) cxt->sector_size,
+		(unsigned) cxt->phy_sector_size));
+
+	return 0;
+}
+
+void fdisk_zeroize_device_properties(struct fdisk_context *cxt)
+{
+	assert(cxt);
+
+	cxt->io_size = 0;
+	cxt->optimal_io_size = 0;
+	cxt->min_io_size = 0;
+	cxt->phy_sector_size = 0;
+	cxt->sector_size = 0;
+	cxt->alignment_offset = 0;
+	cxt->grain = 0;
+	cxt->first_lba = 0;
+	cxt->total_sectors = 0;
+
+	memset(&cxt->geom, 0, sizeof(struct fdisk_geometry));
+}
+
+int fdisk_reset_device_properties(struct fdisk_context *cxt)
+{
+	int rc;
+
+	if (!cxt)
+		return -EINVAL;
+
+	DBG(TOPOLOGY, dbgprint("*** reseting device properties"));
+
+	fdisk_zeroize_device_properties(cxt);
+	fdisk_discover_topology(cxt);
+	fdisk_discover_geometry(cxt);
+
+	rc = fdisk_read_firstsector(cxt);
+	if (rc)
+		return rc;
+
+	fdisk_apply_user_device_properties(cxt);
 	return 0;
 }
 
@@ -187,6 +280,8 @@ int fdisk_discover_geometry(struct fdisk_context *cxt)
 	assert(cxt);
 	assert(cxt->geom.heads == 0);
 
+	DBG(GEOMETRY, dbgprint("%s: discovering geometry...", cxt->dev_path));
+
 	/* get number of 512-byte sectors, and convert it the real sectors */
 	if (!blkdev_get_sectors(cxt->dev_fd, &nsects))
 		cxt->total_sectors = (nsects / (cxt->sector_size >> 9));
@@ -204,9 +299,10 @@ int fdisk_discover_geometry(struct fdisk_context *cxt)
 	cxt->geom.sectors = s;
 	recount_geometry(cxt);
 
-	DBG(GEOMETRY, dbgprint("geometry discovered for %s: C/H/S: %lld/%d/%lld",
-			       cxt->dev_path, cxt->geom.cylinders,
-			       cxt->geom.heads, cxt->geom.sectors));
+	DBG(GEOMETRY, dbgprint("result: C/H/S: %u/%u/%u",
+			       (unsigned) cxt->geom.cylinders,
+			       (unsigned) cxt->geom.heads,
+			       (unsigned) cxt->geom.sectors));
 	return 0;
 }
 
@@ -218,6 +314,7 @@ int fdisk_discover_topology(struct fdisk_context *cxt)
 	assert(cxt);
 	assert(cxt->sector_size == 0);
 
+	DBG(TOPOLOGY, dbgprint("%s: discovering topology...", cxt->dev_path));
 #ifdef HAVE_LIBBLKID
 	DBG(TOPOLOGY, dbgprint("initialize libblkid prober"));
 
@@ -251,11 +348,10 @@ int fdisk_discover_topology(struct fdisk_context *cxt)
 	if (!cxt->io_size)
 		cxt->io_size = cxt->sector_size;
 
-	DBG(TOPOLOGY, dbgprint("topology discovered for %s:\n"
-			       "\tlogical/physical sector sizes: %ld/%ld\n"
-			       "\tfdisk/minimal/optimal io sizes: %ld/%ld/%ld\n",
-			       cxt->dev_path, cxt->sector_size, cxt->phy_sector_size,
-			       cxt->io_size, cxt->optimal_io_size, cxt->min_io_size));
+	DBG(TOPOLOGY, dbgprint("result: log/phy sector size: %ld/%ld",
+			cxt->sector_size, cxt->phy_sector_size));
+	 DBG(TOPOLOGY, dbgprint("result: fdisk/min/optimal io: %ld/%ld/%ld",
+		       cxt->io_size, cxt->optimal_io_size, cxt->min_io_size));
 	return 0;
 }
 
@@ -364,6 +460,8 @@ int fdisk_reset_alignment(struct fdisk_context *cxt)
 	if (!cxt)
 		return -EINVAL;
 
+	DBG(TOPOLOGY, dbgprint("reseting alignment..."));
+
 	/* default */
 	cxt->grain = fdisk_topology_get_grain(cxt);
 	cxt->first_lba = fdisk_topology_get_first_lba(cxt);
diff --git a/libfdisk/src/context.c b/libfdisk/src/context.c
index 6ede3e468..f2b0f7871 100644
--- a/libfdisk/src/context.c
+++ b/libfdisk/src/context.c
@@ -106,7 +106,7 @@ static void reset_context(struct fdisk_context *cxt)
 {
 	size_t i;
 
-	DBG(CONTEXT, dbgprint("\n-----\nresetting context %p", cxt));
+	DBG(CONTEXT, dbgprint("*** resetting context %p", cxt));
 
 	/* reset drives' private data */
 	for (i = 0; i < cxt->nlabels; i++)
@@ -123,17 +123,7 @@ static void reset_context(struct fdisk_context *cxt)
 	cxt->dev_path = NULL;
 	cxt->firstsector = NULL;
 
-	cxt->io_size = 0;
-	cxt->optimal_io_size = 0;
-	cxt->min_io_size = 0;
-	cxt->phy_sector_size = 0;
-	cxt->sector_size = 0;
-	cxt->alignment_offset = 0;
-	cxt->grain = 0;
-	cxt->first_lba = 0;
-	cxt->total_sectors = 0;
-
-	memset(&cxt->geom, 0, sizeof(struct fdisk_geometry));
+	fdisk_zeroize_device_properties(cxt);
 
 	cxt->label = NULL;
 }
@@ -179,7 +169,10 @@ int fdisk_context_assign_device(struct fdisk_context *cxt,
 	/* detect labels and apply labes specific stuff (e.g geomery)
 	 * to the context */
 	fdisk_probe_labels(cxt);
-	fdisk_reset_alignment(cxt);
+
+	/* let's apply user geometry *after* label prober
+	 * to make it possible to override in-label setting */
+	fdisk_apply_user_device_properties(cxt);
 
 	DBG(CONTEXT, dbgprint("context %p initialized for %s [%s]",
 			      cxt, fname,
diff --git a/libfdisk/src/fdiskP.h b/libfdisk/src/fdiskP.h
index 167670fcb..9434f3213 100644
--- a/libfdisk/src/fdiskP.h
+++ b/libfdisk/src/fdiskP.h
@@ -272,9 +272,14 @@ struct fdisk_context {
 	sector_t first_lba;		/* recommended begin of the first partition */
 
 	/* geometry */
-	sector_t total_sectors; /* in logical sectors */
+	sector_t total_sectors;	/* in logical sectors */
 	struct fdisk_geometry geom;
 
+	/* user setting to overwrite device default */
+	struct fdisk_geometry user_geom;
+	unsigned long user_pyh_sector;
+	unsigned long user_log_sector;
+
 	struct fdisk_label *label;	/* current label, pointer to labels[] */
 
 	size_t nlabels;			/* number of initialized label drivers */
@@ -314,7 +319,6 @@ extern sector_t fdisk_align_lba_in_range(struct fdisk_context *cxt, sector_t lba
 					 sector_t start, sector_t stop);
 
 
-extern int fdisk_override_sector_size(struct fdisk_context *cxt, sector_t s);
 extern int fdisk_override_geometry(struct fdisk_context *cxt,
 		            unsigned int cylinders, unsigned int heads,
                             unsigned int sectors);
@@ -322,6 +326,9 @@ extern int fdisk_override_geometry(struct fdisk_context *cxt,
 extern int fdisk_discover_geometry(struct fdisk_context *cxt);
 extern int fdisk_discover_topology(struct fdisk_context *cxt);
 
+extern int fdisk_apply_user_device_properties(struct fdisk_context *cxt);
+extern void fdisk_zeroize_device_properties(struct fdisk_context *cxt);
+
 /* utils.c */
 extern void fdisk_zeroize_firstsector(struct fdisk_context *cxt);
 extern int fdisk_read_firstsector(struct fdisk_context *cxt);
diff --git a/libfdisk/src/label.c b/libfdisk/src/label.c
index d518d876d..cabf3d751 100644
--- a/libfdisk/src/label.c
+++ b/libfdisk/src/label.c
@@ -182,6 +182,8 @@ int fdisk_delete_partition(struct fdisk_context *cxt, size_t partnum)
  */
 int fdisk_create_disklabel(struct fdisk_context *cxt, const char *name)
 {
+	int haslabel = 0;
+
 	if (!cxt)
 		return -EINVAL;
 
@@ -193,8 +195,10 @@ int fdisk_create_disklabel(struct fdisk_context *cxt, const char *name)
 #endif
 	}
 
-	if (cxt->label)
+	if (cxt->label) {
 		fdisk_deinit_label(cxt->label);
+		haslabel = 1;
+	}
 
 	cxt->label = fdisk_context_get_label(cxt, name);
 	if (!cxt->label)
@@ -204,7 +208,8 @@ int fdisk_create_disklabel(struct fdisk_context *cxt, const char *name)
 	if (!cxt->label->op->create)
 		return -ENOSYS;
 
-	fdisk_reset_alignment(cxt);
+	if (haslabel)
+		fdisk_reset_device_properties(cxt);
 	return cxt->label->op->create(cxt);
 }
 
diff --git a/libfdisk/src/libfdisk.h b/libfdisk/src/libfdisk.h
index fc38ef770..3832af070 100644
--- a/libfdisk/src/libfdisk.h
+++ b/libfdisk/src/libfdisk.h
@@ -136,6 +136,16 @@ extern int fdisk_partition_toggle_flag(struct fdisk_context *cxt, size_t partnum
 
 /* alignment.c */
 extern int fdisk_reset_alignment(struct fdisk_context *cxt);
+extern int fdisk_reset_device_properties(struct fdisk_context *cxt);
+
+extern int fdisk_save_user_geometry(struct fdisk_context *cxt,
+			    unsigned int cylinders,
+			    unsigned int heads,
+			    unsigned int sectors);
+
+extern int fdisk_save_user_sector_size(struct fdisk_context *cxt,
+				unsigned int phy,
+				unsigned int log);
 
 
 /* dos.c */