libfdisk: split label and label operations

 Changes:

 - fdisk_label is a private label driver struct
 - generic header of the fdisk_label points to fdisk_label_operations
 - the private fdisk_label stuff is always allocated for all drivers
   during fdisk_context initialization

 - context->labels[] contains pointers to all supported labels (drivers)
 - context->label is a pointer to the currently used label

 This change allows to:

 - store label specific global settings (e.g. dos compatible mode,
   display units, ...) independently on the current label

 - add label specific function to the API

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

1 files changed, 63 insertions, 3 deletions

diff --git a/libfdisk/src/context.c b/libfdisk/src/context.c
index 302020590..83420a977 100644
--- a/libfdisk/src/context.c
+++ b/libfdisk/src/context.c
@@ -1,8 +1,54 @@
 
 #include "fdiskP.h"
 
+static struct fdisk_context *fdisk_new_context(void)
+{
+	struct fdisk_context *cxt;
+	size_t i;
+
+	cxt = calloc(1, sizeof(*cxt));
+	if (!cxt)
+		return NULL;
+
+	/*
+	 * Allocate label specific structs.
+	 *
+	 * This is necessary (for example) to store label specific
+	 * context setting.
+	 */
+	cxt->labels[ cxt->nlabels++ ] = fdisk_new_gpt_label(cxt);
+	cxt->labels[ cxt->nlabels++ ] = fdisk_new_dos_label(cxt);
+	cxt->labels[ cxt->nlabels++ ] = fdisk_new_aix_label(cxt);
+	cxt->labels[ cxt->nlabels++ ] = fdisk_new_bsd_label(cxt);
+	cxt->labels[ cxt->nlabels++ ] = fdisk_new_mac_label(cxt);
+	cxt->labels[ cxt->nlabels++ ] = fdisk_new_sgi_label(cxt);
+	cxt->labels[ cxt->nlabels++ ] = fdisk_new_sun_label(cxt);
+
+	DBG(CONTEXT, dbgprint("supported labels:"));
+	for (i = 0; i < cxt->nlabels; i++) {
+		DBG(CONTEXT, dbgprint(" %s", cxt->labels[i]->name));
+		cxt->labels[i]->cxt = cxt;
+	}
+
+	return cxt;
+}
+
+struct fdisk_label *fdisk_context_get_label(struct fdisk_context *cxt, const char *name)
+{
+	size_t i;
+
+	assert(cxt);
+
+	for (i = 0; i < cxt->nlabels; i++)
+		if (strcmp(cxt->labels[i]->name, name) == 0)
+			return cxt->labels[i];
+
+	DBG(LABEL, dbgprint("failed to found %s label driver\n", name));
+	return NULL;
+}
+
 /**
- * fdisk_new_context:
+ * fdisk_new_context_from_filename:
  * @fname: path to the device to be handled
  * @readonly: how to open the device
  *
@@ -25,7 +71,7 @@ struct fdisk_context *fdisk_new_context_from_filename(const char *fname, int rea
 		readonly = 1;
 	}
 
-	cxt = calloc(1, sizeof(*cxt));
+	cxt = fdisk_new_context();
 	if (!cxt)
 		goto fail;
 
@@ -67,12 +113,26 @@ fail:
  */
 void fdisk_free_context(struct fdisk_context *cxt)
 {
+	int i;
+
 	if (!cxt)
 		return;
 
 	DBG(CONTEXT, dbgprint("freeing context %p for %s", cxt, cxt->dev_path));
-	close(cxt->dev_fd);
+	if (cxt->dev_fd > -1)
+		close(cxt->dev_fd);
 	free(cxt->dev_path);
 	free(cxt->firstsector);
+
+	/* deallocate label's private stuff */
+	for (i = 0; i < cxt->nlabels; i++) {
+		if (!cxt->labels[i])
+			continue;
+		if (cxt->labels[i]->op->free)
+			cxt->labels[i]->op->free(cxt->labels[i]);
+		else
+			free(cxt->labels[i]);
+	}
+
 	free(cxt);
 }