From a260002a6ca600af140c757faf4cbc7ed1f15890 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexe=C3=AF=20KADIR?= <alexei.kadir@gmail.com>
Date: Mon, 19 Feb 2024 20:23:26 +0100
Subject: [PATCH] Made some small modifications (backing extraction)

---
 src/backing.c   | 18 +++++++++---------
 src/backing.h   |  2 +-
 src/container.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++-
 src/container.h |  8 +++++++-
 4 files changed, 64 insertions(+), 12 deletions(-)

diff --git a/src/backing.c b/src/backing.c
index 99e87f4..400d2f3 100755
--- a/src/backing.c
+++ b/src/backing.c
@@ -396,24 +396,24 @@ result_t get_backing_parent(char** _parent, const char* backing) {
 		return result;
 	}
 
-	// If the disk is not backed, return success and a null parent
+	// Free the backing path as it is not needed anymore
+	free(path);
+
+	// Check if the disk is backed
 	if (info.backing_path == NULL) {
 		free_disk_info(&info);
-		free(path);
 		return success();
 	}
 
 	// Get the backing identifier of the parent
 	char* parent = strdup(basename(info.backing_path));
-	if (parent == NULL) {
-		free_disk_info(&info);
-		free(path);
-		return failure("Failed to get the backing identifier of the parent.");
-	}
 
+	// Free the disk info as it is not needed anymore
 	free_disk_info(&info);
-	free(path);
+
+	if (parent == NULL)
+		return failure("Failed to get the backing identifier of the parent.");
 
 	*_parent = parent;
-	return result;
+	return success();
 }
diff --git a/src/backing.h b/src/backing.h
index 94669a4..c94d4a0 100755
--- a/src/backing.h
+++ b/src/backing.h
@@ -66,7 +66,7 @@ result_t list_backings(char*** _backings);
 result_t get_default_backing(char** _backing);
 
 /// @brief Sets the default backing identifier.
-/// @param backing The backing identifier to set as the default.
+/// @param backing The backing identifier to set as the default. This parameter can be NULL to remove the default backing.
 /// @return The result of the operation.
 result_t set_default_backing(const char* backing);
 
diff --git a/src/container.c b/src/container.c
index e9136e6..5e00b44 100755
--- a/src/container.c
+++ b/src/container.c
@@ -7,6 +7,7 @@
 #include <errno.h>
 #include <string.h>
 #include <unistd.h>
+#include <libgen.h>
 #include <sys/stat.h>
 
 result_t check_container_identifier(const char* container) {
@@ -235,4 +236,49 @@ result_t list_containers(char*** _containers) {
 
 	free(pool_path);
 	return result;
-}
\ No newline at end of file
+}
+
+result_t get_container_backing(char** _backing, const char* container) {
+	// Initialize the output parameters
+	*_backing = NULL;
+
+	// Check that the container exists
+	result_t result = check_container_exists(container);
+	if (result != success())
+		return result;
+
+	// Get the container path
+	char* path;
+	result = get_container_path(&path, container);
+	if (result != success())
+		return result;
+
+	// Get the disk information
+	disk_info_t info;
+	result = get_disk_info(&info, path);
+	if (result != success()) {
+		free(path);
+		return result;
+	}
+
+	// Free the container path as it is no longer needed
+	free(path);
+
+	// Check if the disk is backed
+	if (info.backing_path == NULL) {
+		free_disk_info(&info);
+		success();
+	}
+
+	// Get the backing identifier
+	char* backing = strdup(basename(info.backing_path));
+	
+	// Free the disk information as it is no longer needed
+	free_disk_info(&info);
+
+	if (backing == NULL)
+		return failure("Failed to get backing identifier for container '%s'.", container);
+
+	*_backing = backing;
+	return success();
+}
diff --git a/src/container.h b/src/container.h
index 9312b4b..ee5e35b 100755
--- a/src/container.h
+++ b/src/container.h
@@ -60,4 +60,10 @@ bool container_filter(const char* file);
 /// @brief Lists the containers in the pool.
 /// @param _containers The string pointer array to store the resulting array in. The caller is responsible for freeing the strings and the array.
 /// @return The result of the operation.
-result_t list_containers(char*** _containers);
\ No newline at end of file
+result_t list_containers(char*** _containers);
+
+/// @brief Gets the backing of the given container. If the container does not exist, the call will return a failure result with an error message.
+/// @param _backing The string pointer to store the resulting backing in.
+/// @param container The container to get the backing of.
+/// @return The result of the operation.
+result_t get_container_backing(char** _backing, const char* container);
\ No newline at end of file