libfdisk: add fdisk_wipe_partition()

Now libfdisk provides functionality wipe disk device only ([s]fdisk
option --wipe).

This patch allows to probe for filesystems/RAIDs on newly created
partitions.  It means we can remove signatures before the partition
node (device) is created. This reduces udev events and it's
unnecessary to call wipefs for all partitions.  For example

  sfdisk --wipe=always --wipe-partitions=always /dev/sda <<<
  ...
  EOF

is a elegant way how to create new disk layout without any obsolete
filesystems/RAIDs.

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

1 files changed, 21 insertions, 36 deletions

diff --git a/libfdisk/src/context.c b/libfdisk/src/context.c
index 88b9f8afb..26f526a78 100644
--- a/libfdisk/src/context.c
+++ b/libfdisk/src/context.c
@@ -47,6 +47,8 @@ struct fdisk_context *fdisk_new_context(void)
 	cxt->dev_fd = -1;
 	cxt->refcount = 1;
 
+	INIT_LIST_HEAD(&cxt->wipes);
+
 	/*
 	 * Allocate label specific structs.
 	 *
@@ -112,6 +114,8 @@ static int init_nested_from_parent(struct fdisk_context *cxt, int isnew)
 			return -ENOMEM;
 	}
 
+	INIT_LIST_HEAD(&cxt->wipes);
+
 	return 0;
 }
 
@@ -339,9 +343,15 @@ int fdisk_enable_bootbits_protection(struct fdisk_context *cxt, int enable)
  * @cxt: fdisk context
  * @enable: 1 or 0
  *
- * The library removes all filesystem/RAID signatures before write PT. This is
- * no-op if any collision has not been detected by fdisk_assign_device(). See
- * fdisk_has_collision(). The default is not wipe a device.
+ * The library removes all filesystem/RAID signatures before it writes
+ * partition table. The probing area where it looks for filesystem/RAID is from
+ * the begin of the disk. The device is wiped by libblkid.
+ *
+ * See also fdisk_wipe_partition().
+ *
+ * This is no-op if any collision has not been detected by
+ * fdisk_assign_device(). See fdisk_has_collision(). The default is not wipe a
+ * device.
  *
  * Returns: 0 on success, < 0 on error.
  */
@@ -349,7 +359,8 @@ int fdisk_enable_wipe(struct fdisk_context *cxt, int enable)
 {
 	if (!cxt)
 		return -EINVAL;
-	cxt->wipe_device = enable ? 1 : 0;
+
+	fdisk_set_wipe_area(cxt, 0, cxt->total_sectors * cxt->sector_size, enable);
 	return 0;
 }
 
@@ -363,7 +374,10 @@ int fdisk_enable_wipe(struct fdisk_context *cxt, int enable)
  */
 int fdisk_has_wipe(struct fdisk_context *cxt)
 {
-	return cxt && cxt->wipe_device;
+	if (!cxt)
+		return 0;
+
+	return fdisk_has_wipe_area(cxt, 0, cxt->total_sectors * cxt->sector_size);
 }
 
 
@@ -484,6 +498,8 @@ static void reset_context(struct fdisk_context *cxt)
 	cxt->script = NULL;
 
 	cxt->label = NULL;
+
+	fdisk_free_wipe_areas(cxt);
 }
 
 /*
@@ -535,37 +551,6 @@ static int check_collisions(struct fdisk_context *cxt)
 #endif
 }
 
-int fdisk_wipe_collisions(struct fdisk_context *cxt)
-{
-#ifdef HAVE_LIBBLKID
-	blkid_probe pr;
-	int rc;
-
-	assert(cxt);
-	assert(cxt->dev_fd >= 0);
-
-	DBG(CXT, ul_debugobj(cxt, "wipe: initialize libblkid prober"));
-
-	pr = blkid_new_probe();
-	if (!pr)
-		return -ENOMEM;
-	rc = blkid_probe_set_device(pr, cxt->dev_fd, 0, 0);
-	if (rc)
-		return rc;
-
-	blkid_probe_enable_superblocks(pr, 1);
-	blkid_probe_set_superblocks_flags(pr, BLKID_SUBLKS_MAGIC);
-	blkid_probe_enable_partitions(pr, 1);
-	blkid_probe_set_partitions_flags(pr, BLKID_PARTS_MAGIC);
-
-	while (blkid_do_probe(pr) == 0)
-		blkid_do_wipe(pr, FALSE);
-
-	blkid_free_probe(pr);
-#endif
-	return 0;
-}
-
 /**
  * fdisk_assign_device:
  * @cxt: context