From 7c57d736c640c2c08319878cd8d5b4bb6a2fdb87 Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Tue, 28 Jan 2025 17:15:11 +0200
Subject: [PATCH] Kernel/LibC: Fix dirent functions

dirent functions used to fail if a directory contained more than 128
files :D
---
 kernel/kernel/OpenFileDescriptorSet.cpp |  7 ++++--
 userspace/libraries/LibC/dirent.cpp     | 30 ++++++++++++++++++++-----
 2 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/kernel/kernel/OpenFileDescriptorSet.cpp b/kernel/kernel/OpenFileDescriptorSet.cpp
index 81486da0..d246148a 100644
--- a/kernel/kernel/OpenFileDescriptorSet.cpp
+++ b/kernel/kernel/OpenFileDescriptorSet.cpp
@@ -330,8 +330,11 @@ namespace Kernel
 			return BAN::Error::from_errno(EACCES);
 		for (;;)
 		{
-			auto ret = open_file.inode()->list_next_inodes(open_file.offset()++, list, list_len);
-			if (ret.is_error() && ret.error().get_error_code() == ENODATA)
+			auto ret = open_file.inode()->list_next_inodes(open_file.offset(), list, list_len);
+			if (ret.is_error() && ret.error().get_error_code() != ENODATA)
+				return ret;
+			open_file.offset()++;
+			if (ret.is_error())
 				continue;
 			return ret;
 		}
diff --git a/userspace/libraries/LibC/dirent.cpp b/userspace/libraries/LibC/dirent.cpp
index d3c43299..339a6157 100644
--- a/userspace/libraries/LibC/dirent.cpp
+++ b/userspace/libraries/LibC/dirent.cpp
@@ -10,9 +10,10 @@ struct __DIR
 	int fd { -1 };
 	size_t entry_count { 0 };
 	size_t entry_index { 0 };
-	// FIXME: we should probably allocate entries dynamically
-	//        based if syscall returns ENOBUFS
-	dirent entries[128];
+	size_t entries_size { 0 };
+	dirent* entries { nullptr };
+
+	static constexpr size_t default_entries_size { 128 };
 };
 
 int closedir(DIR* dirp)
@@ -42,10 +43,18 @@ int dirfd(DIR* dirp)
 
 DIR* fdopendir(int fd)
 {
-	DIR* dirp = (DIR*)malloc(sizeof(DIR));
+	DIR* dirp = static_cast<DIR*>(malloc(sizeof(DIR)));
 	if (dirp == nullptr)
 		return nullptr;
 
+	dirp->entries = static_cast<dirent*>(malloc(DIR::default_entries_size * sizeof(dirent)));
+	dirp->entries_size = DIR::default_entries_size;
+	if (dirp->entries == nullptr)
+	{
+		free(dirp);
+		return nullptr;
+	}
+
 	dirp->fd = fd;
 	dirp->entry_count = 0;
 	dirp->entry_index = 0;
@@ -73,7 +82,18 @@ struct dirent* readdir(DIR* dirp)
 	if (dirp->entry_index < dirp->entry_count)
 		return &dirp->entries[dirp->entry_index];
 
-	long entry_count = syscall(SYS_READ_DIR, dirp->fd, dirp->entries, sizeof(dirp->entries) / sizeof(dirp->entries[0]));
+readdir_do_syscall:
+	long entry_count = syscall(SYS_READ_DIR, dirp->fd, dirp->entries, dirp->entries_size);
+	if (entry_count == -1 && errno == ENOBUFS)
+	{
+		const size_t new_entries_size = dirp->entries_size * 2;
+		dirent* new_entries = static_cast<dirent*>(malloc(new_entries_size * sizeof(dirent)));
+		if (new_entries == nullptr)
+			return nullptr;
+		dirp->entries = new_entries;
+		dirp->entries_size = new_entries_size;
+		goto readdir_do_syscall;
+	}
 	if (entry_count <= 0)
 		return nullptr;