[libc] Add <sys/statfs.h> header and entrypoints. (#213108)

Implement `statfs` and `fstatfs` functions on Linux.

We already have `struct statfs` and syscall wrappers defined (to
implement POSIX `<sys/statvfs.h>`). Use them to provide Linux-specific
functions as well.

libc/config/linux/aarch64/entrypoints.txt

@@ -334,7 +334,11 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.sys.stat.stat
     libc.src.sys.stat.utimensat
 
-    # sys/statvfs.h
+    # sys/statfs.h entrypoints
+    libc.src.sys.statfs.fstatfs
+    libc.src.sys.statfs.statfs
+
+    # sys/statvfs.h entrypoints
     libc.src.sys.statvfs.fstatvfs
     libc.src.sys.statvfs.statvfs
 

libc/config/linux/aarch64/headers.txt

@@ -62,6 +62,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.sys_signal
     libc.include.sys_socket
     libc.include.sys_stat
+    libc.include.sys_statfs
     libc.include.sys_statvfs
     libc.include.sys_syscall
     libc.include.sys_time

libc/config/linux/riscv/entrypoints.txt

@@ -365,7 +365,11 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.sys.stat.stat
     libc.src.sys.stat.utimensat
 
-    # sys/statvfs.h
+    # sys/statfs.h entrypoints
+    libc.src.sys.statfs.fstatfs
+    libc.src.sys.statfs.statfs
+
+    # sys/statvfs.h entrypoints
     libc.src.sys.statvfs.fstatvfs
     libc.src.sys.statvfs.statvfs
 

libc/config/linux/riscv/headers.txt

@@ -63,6 +63,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.sys_signal
     libc.include.sys_socket
     libc.include.sys_stat
+    libc.include.sys_statfs
     libc.include.sys_statvfs
     libc.include.sys_syscall
     libc.include.sys_time

libc/config/linux/x86_64/entrypoints.txt

@@ -370,7 +370,11 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.sys.stat.stat
     libc.src.sys.stat.utimensat
 
-    # sys/statvfs.h
+    # sys/statfs.h entrypoints
+    libc.src.sys.statfs.fstatfs
+    libc.src.sys.statfs.statfs
+
+    # sys/statvfs.h entrypoints
     libc.src.sys.statvfs.fstatvfs
     libc.src.sys.statvfs.statvfs
 

libc/config/linux/x86_64/headers.txt

@@ -65,6 +65,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.sys_signal
     libc.include.sys_socket
     libc.include.sys_stat
+    libc.include.sys_statfs
     libc.include.sys_statvfs
     libc.include.sys_syscall
     libc.include.sys_time

libc/include/CMakeLists.txt

@@ -861,6 +861,16 @@ add_header_macro(
     .llvm-libc-types.struct_ucred
 )
 
+add_header_macro(
+  sys_statfs
+  ../libc/include/sys/statfs.yaml
+  sys/statfs.h
+  DEPENDS
+    .llvm_libc_common_h
+    .llvm-libc-macros.sys_statfs_macros
+    .llvm-libc-types.struct_statfs
+)
+
 add_header_macro(
   sys_statvfs
   ../libc/include/sys/statvfs.yaml

libc/include/llvm-libc-macros/CMakeLists.txt

@@ -267,6 +267,12 @@ add_macro_header(
     sys-stat-macros.h
 )
 
+add_macro_header(
+  sys_statfs_macros
+  HDR
+    sys-statfs-macros.h
+)
+
 add_macro_header(
   sys_mman_macros
   HDR

libc/include/llvm-libc-macros/linux/CMakeLists.txt

@@ -100,6 +100,12 @@ add_header(
     sys-stat-macros.h
 )
 
+add_header(
+  sys_statfs_macros
+  HDR
+    sys-statfs-macros.h
+)
+
 add_header(
   sys_time_macros
   HDR

libc/include/llvm-libc-macros/linux/sys-statfs-macros.h

@@ -0,0 +1,21 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Linux specific declarations of macros from sys/statfs.h.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_MACROS_LINUX_SYS_STATFS_MACROS_H
+#define LLVM_LIBC_MACROS_LINUX_SYS_STATFS_MACROS_H
+
+// There are numerous possible values for f_type field, defined in
+// the Linux kernel header. Include it directly.
+#include <linux/magic.h>
+
+#endif // LLVM_LIBC_MACROS_LINUX_SYS_STATFS_MACROS_H

libc/include/llvm-libc-macros/sys-statfs-macros.h

@@ -0,0 +1,21 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Macros defined in sys/statfs.h header file.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_MACROS_SYS_STATFS_MACROS_H
+#define LLVM_LIBC_MACROS_SYS_STATFS_MACROS_H
+
+#ifdef __linux__
+#include "linux/sys-statfs-macros.h"
+#endif
+
+#endif // LLVM_LIBC_MACROS_SYS_STATFS_MACROS_H

libc/include/sys/statfs.yaml

@@ -0,0 +1,19 @@
+header: sys/statfs.h
+standards:
+  - linux
+macros:
+  - macro_name: ADFS_SUPER_MAGIC
+    macro_header: sys-statfs-macros.h
+types:
+  - type_name: struct_statfs
+functions:
+  - name: fstatfs
+    return_type: int
+    arguments:
+      - type: int
+      - type: struct statfs *
+  - name: statfs
+    return_type: int
+    arguments:
+      - type: const char *
+      - type: struct statfs *

libc/src/sys/CMakeLists.txt

@@ -10,6 +10,7 @@ add_subdirectory(socket)
 add_subdirectory(sem)
 add_subdirectory(sendfile)
 add_subdirectory(stat)
+add_subdirectory(statfs)
 add_subdirectory(statvfs)
 add_subdirectory(time)
 add_subdirectory(utsname)

libc/src/sys/statfs/CMakeLists.txt

@@ -0,0 +1,17 @@
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+  add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+endif()
+
+add_entrypoint_object(
+  statfs
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.statfs
+)
+
+add_entrypoint_object(
+  fstatfs
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.fstatfs
+)

libc/src/sys/statfs/fstatfs.h

@@ -0,0 +1,26 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Implementation header for fstatfs.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SYS_STATFS_FSTATFS_H
+#define LLVM_LIBC_SRC_SYS_STATFS_FSTATFS_H
+
+#include "hdr/types/struct_statfs.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int fstatfs(int fd, struct statfs *buf);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_SYS_STATFS_FSTATFS_H

libc/src/sys/statfs/linux/CMakeLists.txt

@@ -0,0 +1,23 @@
+add_entrypoint_object(
+  statfs
+  SRCS
+    statfs.cpp
+  HDRS
+    ../statfs.h
+  DEPENDS
+    libc.src.errno.errno
+    libc.src.__support.OSUtil.linux.syscall_wrappers.statfs
+    libc.hdr.types.struct_statfs
+)
+
+add_entrypoint_object(
+  fstatfs
+  SRCS
+    fstatfs.cpp
+  HDRS
+    ../fstatfs.h
+  DEPENDS
+    libc.src.errno.errno
+    libc.src.__support.OSUtil.linux.syscall_wrappers.fstatfs
+    libc.hdr.types.struct_statfs
+)

libc/src/sys/statfs/linux/fstatfs.cpp

@@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Linux implementation of fstatfs.
+///
+//===----------------------------------------------------------------------===//
+
+#include "src/sys/statfs/fstatfs.h"
+#include "src/__support/OSUtil/linux/syscall_wrappers/fstatfs.h"
+#include "src/__support/common.h"
+#include "src/__support/libc_errno.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, fstatfs, (int fd, struct statfs *buf)) {
+  auto error_or_ret = linux_syscalls::fstatfs(fd, buf);
+  if (!error_or_ret) {
+    libc_errno = error_or_ret.error();
+    return -1;
+  }
+  return 0;
+}
+
+} // namespace LIBC_NAMESPACE_DECL

libc/src/sys/statfs/linux/statfs.cpp

@@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Linux implementation of statfs.
+///
+//===----------------------------------------------------------------------===//
+
+#include "src/sys/statfs/statfs.h"
+#include "src/__support/OSUtil/linux/syscall_wrappers/statfs.h"
+#include "src/__support/common.h"
+#include "src/__support/libc_errno.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, statfs, (const char *path, struct statfs *buf)) {
+  auto error_or_ret = linux_syscalls::statfs(path, buf);
+  if (!error_or_ret) {
+    libc_errno = error_or_ret.error();
+    return -1;
+  }
+  return 0;
+}
+
+} // namespace LIBC_NAMESPACE_DECL

libc/src/sys/statfs/statfs.h

@@ -0,0 +1,26 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Implementation header for statfs.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SYS_STATFS_STATFS_H
+#define LLVM_LIBC_SRC_SYS_STATFS_STATFS_H
+
+#include "hdr/types/struct_statfs.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int statfs(const char *path, struct statfs *buf);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_SYS_STATFS_STATFS_H

libc/test/src/sys/CMakeLists.txt

@@ -6,6 +6,7 @@ add_subdirectory(select)
 add_subdirectory(sendfile)
 add_subdirectory(socket)
 add_subdirectory(stat)
+add_subdirectory(statfs)
 add_subdirectory(statvfs)
 add_subdirectory(utsname)
 add_subdirectory(wait)

libc/test/src/sys/statfs/CMakeLists.txt

@@ -0,0 +1,3 @@
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+  add_subdirectory(${LIBC_TARGET_OS})
+endif()

libc/test/src/sys/statfs/linux/CMakeLists.txt

@@ -0,0 +1,35 @@
+add_custom_target(libc_sys_statfs_unittests)
+
+add_libc_unittest(
+  statfs_test
+  SUITE
+    libc_sys_statfs_unittests
+  SRCS
+    statfs_test.cpp
+  DEPENDS
+    libc.hdr.sys_stat_macros
+    libc.src.errno.errno
+    libc.src.sys.statfs.statfs
+    libc.src.sys.stat.mkdirat
+    libc.src.unistd.rmdir
+    libc.test.UnitTest.ErrnoCheckingTest
+    libc.test.UnitTest.ErrnoSetterMatcher
+)
+
+add_libc_unittest(
+  fstatfs_test
+  SUITE
+    libc_sys_statfs_unittests
+  SRCS
+    fstatfs_test.cpp
+  DEPENDS
+    libc.hdr.sys_stat_macros
+    libc.src.errno.errno
+    libc.src.sys.statfs.fstatfs
+    libc.src.sys.stat.mkdirat
+    libc.src.unistd.rmdir
+    libc.src.fcntl.open
+    libc.src.unistd.close
+    libc.test.UnitTest.ErrnoCheckingTest
+    libc.test.UnitTest.ErrnoSetterMatcher
+)

libc/test/src/sys/statfs/linux/fstatfs_test.cpp

@@ -0,0 +1,65 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Unittests for fstatfs.
+///
+//===----------------------------------------------------------------------===//
+
+#include "hdr/fcntl_macros.h"
+#include "hdr/sys_stat_macros.h"
+#include "src/__support/libc_errno.h"
+#include "src/__support/macros/config.h"
+#include "src/fcntl/open.h"
+#include "src/sys/stat/mkdirat.h"
+#include "src/sys/statfs/fstatfs.h"
+#include "src/unistd/close.h"
+#include "src/unistd/rmdir.h"
+#include "test/UnitTest/ErrnoCheckingTest.h"
+#include "test/UnitTest/ErrnoSetterMatcher.h"
+#include "test/UnitTest/Test.h"
+
+using namespace LIBC_NAMESPACE::testing::ErrnoSetterMatcher;
+using LlvmLibcSysFStatfsTest = LIBC_NAMESPACE::testing::ErrnoCheckingTest;
+
+TEST_F(LlvmLibcSysFStatfsTest, FStatfsBasic) {
+  struct statfs buf;
+
+  int fd = LIBC_NAMESPACE::open("/", O_PATH);
+  ASSERT_ERRNO_SUCCESS();
+  ASSERT_GT(fd, 0);
+
+  // The root of the file directory must always exist
+  ASSERT_THAT(LIBC_NAMESPACE::fstatfs(fd, &buf), Succeeds());
+  ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
+}
+
+TEST_F(LlvmLibcSysFStatfsTest, FStatfsInvalidPath) {
+  struct statfs buf;
+
+  constexpr const char *FILENAME = "fstatfs.testdir";
+  auto TEST_DIR = libc_make_test_file_path(FILENAME);
+
+  // Always delete the folder so that we start in a consistent state.
+  LIBC_NAMESPACE::rmdir(TEST_DIR);
+  libc_errno = 0; // Reset errno
+
+  ASSERT_THAT(LIBC_NAMESPACE::mkdirat(AT_FDCWD, TEST_DIR, S_IRWXU),
+              Succeeds(0));
+
+  int fd = LIBC_NAMESPACE::open(TEST_DIR, O_PATH);
+  ASSERT_ERRNO_SUCCESS();
+  ASSERT_GT(fd, 0);
+
+  ASSERT_THAT(LIBC_NAMESPACE::fstatfs(fd, &buf), Succeeds());
+  ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
+
+  ASSERT_THAT(LIBC_NAMESPACE::rmdir(TEST_DIR), Succeeds(0));
+
+  ASSERT_THAT(LIBC_NAMESPACE::fstatfs(fd, &buf), Fails(EBADF));
+}

libc/test/src/sys/statfs/linux/statfs_test.cpp

@@ -0,0 +1,56 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Unittests for statfs.
+///
+//===----------------------------------------------------------------------===//
+
+#include "hdr/fcntl_macros.h"
+#include "hdr/sys_stat_macros.h"
+#include "src/__support/libc_errno.h"
+#include "src/__support/macros/config.h"
+#include "src/sys/stat/mkdirat.h"
+#include "src/sys/statfs/statfs.h"
+#include "src/unistd/rmdir.h"
+#include "test/UnitTest/ErrnoCheckingTest.h"
+#include "test/UnitTest/ErrnoSetterMatcher.h"
+#include "test/UnitTest/Test.h"
+
+using namespace LIBC_NAMESPACE::testing::ErrnoSetterMatcher;
+using LlvmLibcSysStatfsTest = LIBC_NAMESPACE::testing::ErrnoCheckingTest;
+
+TEST_F(LlvmLibcSysStatfsTest, StatfsBasic) {
+  struct statfs buf;
+  // The root of the file directory must always exist
+  ASSERT_THAT(LIBC_NAMESPACE::statfs("/", &buf), Succeeds());
+}
+
+TEST_F(LlvmLibcSysStatfsTest, StatfsInvalidPath) {
+  struct statfs buf;
+
+  ASSERT_THAT(LIBC_NAMESPACE::statfs("", &buf), Fails(ENOENT));
+
+  // create the file, assert it exists, then delete it and assert it doesn't
+  // exist anymore.
+  constexpr const char *FILENAME = "statfs.testdir";
+  auto TEST_DIR = libc_make_test_file_path(FILENAME);
+
+  // Always delete the folder so that we start in a consistent state.
+  LIBC_NAMESPACE::rmdir(TEST_DIR);
+  libc_errno = 0; // Reset errno
+
+  ASSERT_THAT(LIBC_NAMESPACE::mkdirat(AT_FDCWD, TEST_DIR, S_IRWXU),
+              Succeeds(0));
+
+  ASSERT_THAT(LIBC_NAMESPACE::statfs(TEST_DIR, &buf), Succeeds());
+
+  ASSERT_THAT(LIBC_NAMESPACE::rmdir(TEST_DIR), Succeeds(0));
+
+  ASSERT_THAT(LIBC_NAMESPACE::statfs(TEST_DIR, &buf), Fails(ENOENT));
+}