Add creat function call. Fix direntry iteration in EXT2. Fix open of directories in EXT2. Fix re-utilization of unlinked direntries in EXT2.

libc/CMakeLists.txt

@@ -84,6 +84,7 @@ add_library(
     ${PROJECT_SOURCE_DIR}/src/sys/errno.c
     ${PROJECT_SOURCE_DIR}/src/sys/utsname.c
     ${PROJECT_SOURCE_DIR}/src/sys/ioctl.c
+    ${PROJECT_SOURCE_DIR}/src/unistd/creat.c
     ${PROJECT_SOURCE_DIR}/src/unistd/getppid.c
     ${PROJECT_SOURCE_DIR}/src/unistd/getpid.c
     ${PROJECT_SOURCE_DIR}/src/unistd/exit.c

libc/inc/sys/stat.h

@@ -32,4 +32,12 @@ int mkdir(const char *path, mode_t mode);
 /// @brief Removes the given directory.
 /// @param path The path to the directory to remove.
 /// @return Returns a negative value on failure.
-int rmdir(const char *path);
+int rmdir(const char *path);
+
+/// @brief Creates a new file or rewrite an existing one.
+/// @param path path to the file.
+/// @param mode mode for file creation.
+/// @return file descriptor number, -1 otherwise and errno is set to indicate the error.
+/// @details
+/// It is equivalent to: open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)
+int creat(const char *path, mode_t mode);

libc/inc/sys/unistd.h

@@ -28,14 +28,11 @@ ssize_t read(int fd, void *buf, size_t nbytes);
 /// @return       The number of written bytes.
 ssize_t write(int fd, void *buf, size_t nbytes);
 
-/// @brief          Opens the file specified by pathname.
+/// @brief Opens the file specified by pathname.
 /// @param pathname A pathname for a file.
-/// @param flags    Used to set the file status flags and file access modes
-///                 of the open file description.
-/// @param mode     Specifies the file mode bits be applied when a new file
-///                 is created.
-/// @return         Returns a file descriptor, a small, nonnegative integer for
-///                 use in subsequent system calls.
+/// @param flags file status flags and file access modes of the open file description.
+/// @param mode the file mode bits be applied when a new file is created.
+/// @return file descriptor number, -1 otherwise and errno is set to indicate the error.
 int open(const char *pathname, int flags, mode_t mode);
 
 /// @brief Close a file descriptor.

libc/src/unistd/creat.c

@@ -0,0 +1,11 @@
+///                MentOS, The Mentoring Operating system project
+/// @file creat.c
+/// @brief
+/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
+
+#include "sys/unistd.h"
+#include "system/syscall_types.h"
+#include "sys/errno.h"
+
+_syscall2(int, creat, const char *, pathname, mode_t, mode)