[libc] add statvfs/fstatvfs

libc/config/linux/api.td

@@ -262,3 +262,7 @@ def SetJmpAPI : PublicAPI<"setjmp.h"> {
 def SearchAPI : PublicAPI<"search.h"> {
   let Types = ["ACTION", "ENTRY", "struct hsearch_data"];
 }
+
+def SysStatvfsAPI : PublicAPI<"sys/statvfs.h"> {
+  let Types = ["fsblkcnt_t", "fsfilcnt_t", "struct statvfs"];
+}

libc/config/linux/x86_64/entrypoints.txt

@@ -253,6 +253,10 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.sys.stat.mkdirat
     libc.src.sys.stat.stat
 
+    # sys/statvfs.h
+    libc.src.sys.statvfs.statvfs
+    libc.src.sys.statvfs.fstatvfs
+
     # sys/utsname.h entrypoints
     libc.src.sys.utsname.uname
 

libc/include/CMakeLists.txt

@@ -498,6 +498,15 @@ add_gen_header(
     .llvm-libc-types.struct_sockaddr_un
 )
 
+add_gen_header(
+  sys_statvfs
+  DEF_FILE sys/statvfs.h.def
+  GEN_HDR sys/statvfs.h
+  DEPENDS
+    .llvm_libc_common_h
+    .llvm-libc-types.struct_statvfs
+)
+
 add_gen_header(
   sys_syscall
   DEF_FILE sys/syscall.h.def

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

@@ -106,3 +106,13 @@ add_header(
   DEPENDS
     libc.include.llvm-libc-macros.float_macros
 )
+add_header(fsblkcnt_t HDR fsblkcnt_t.h)
+add_header(fsfilcnt_t HDR fsfilcnt_t.h)
+add_header(
+  struct_statvfs 
+HDR 
+  struct_statvfs.h
+DEPENDS
+  .fsblkcnt_t
+  .fsfilcnt_t
+)

libc/include/llvm-libc-types/fsblkcnt_t.h

@@ -0,0 +1,14 @@
+//===-- Definition of fsblkcnt_t type -------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_TYPES_FSBLKCNT_T_H
+#define LLVM_LIBC_TYPES_FSBLKCNT_T_H
+
+typedef __SIZE_TYPE__ fsblkcnt_t;
+
+#endif // LLVM_LIBC_TYPES_FSBLKCNT_T_H

libc/include/llvm-libc-types/fsfilcnt_t.h

@@ -0,0 +1,14 @@
+//===-- Definition of fsfilcnt_t type -------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_TYPES_FSFILCNT_T_H
+#define LLVM_LIBC_TYPES_FSFILCNT_T_H
+
+typedef __SIZE_TYPE__ fsfilcnt_t;
+
+#endif // LLVM_LIBC_TYPES_FSFILCNT_T_H

libc/include/llvm-libc-types/struct_statvfs.h

@@ -0,0 +1,29 @@
+//===-- Definition of type struct statvfs ---------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_TYPES_STRUCT_STATVFS_H
+#define LLVM_LIBC_TYPES_STRUCT_STATVFS_H
+
+#include <llvm-libc-types/fsblkcnt_t.h>
+#include <llvm-libc-types/fsfilcnt_t.h>
+
+struct statvfs {
+  unsigned long f_bsize;   /* Filesystem block size */
+  unsigned long f_frsize;  /* Fragment size */
+  fsblkcnt_t f_blocks;     /* Size of fs in f_frsize units */
+  fsblkcnt_t f_bfree;      /* Number of free blocks */
+  fsblkcnt_t f_bavail;     /* Number of free blocks for unprivileged users */
+  fsfilcnt_t f_files;      /* Number of inodes */
+  fsfilcnt_t f_ffree;      /* Number of free inodes */
+  fsfilcnt_t f_favail;     /* Number of free inodes for unprivileged users */
+  unsigned long f_fsid;    /* Filesystem ID */
+  unsigned long f_flag;    /* Mount flags */
+  unsigned long f_namemax; /* Maximum filename length */
+};
+
+#endif // LLVM_LIBC_TYPES_STRUCT_STATVFS_H

libc/include/sys/statvfs.h.def

@@ -0,0 +1,16 @@
+//===-- POSIX header statvfs.h --------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SYS_STATVFS_H
+#define LLVM_LIBC_SYS_STATVFS_H
+
+#include <__llvm-libc-common.h>
+
+%%public_api()
+
+#endif // LLVM_LIBC_SYS_STATVFS_H

libc/spec/posix.td

@@ -86,6 +86,10 @@ def ConstStructSockAddrPtr : ConstType<StructSockAddrPtr>;
 
 def StructSockAddrUn : NamedType<"struct sockaddr_un">;
 
+def StructStatvfs : NamedType<"struct statvfs">;
+def StructStatvfsPtr : PtrType<StructStatvfs>;
+def RestrictedStructStatvfsPtr : RestrictedPtrType<StructStatvfs>;
+
 def POSIX : StandardSpec<"POSIX"> {
   PtrType CharPtr = PtrType<CharType>;
   RestrictedPtrType RestrictedCharPtr = RestrictedPtrType<CharType>;
@@ -888,6 +892,31 @@ def POSIX : StandardSpec<"POSIX"> {
     ]
   >;
 
+  HeaderSpec SysStatvfs = HeaderSpec<
+      "sys/statvfs.h",
+      [], // Macros
+      [StructStatvfs], // Types
+      [], // Enumerations
+      [
+        FunctionSpec<
+          "statvfs",
+          RetValSpec<IntType>,
+          [
+            ArgSpec<ConstRestrictedCharPtr>,
+            ArgSpec<RestrictedStructStatvfsPtr>
+          ]
+        >,
+        FunctionSpec<
+          "fstatvfs",
+          RetValSpec<IntType>,
+          [
+            ArgSpec<IntType>,
+            ArgSpec<StructStatvfsPtr>
+          ]
+        >,
+      ]  // Functions
+    >;
+
   NamedType StructUtsName = NamedType<"struct utsname">;
   PtrType StructUtsNamePtr = PtrType<StructUtsName>;
   HeaderSpec SysUtsName = HeaderSpec<
@@ -1505,6 +1534,7 @@ def POSIX : StandardSpec<"POSIX"> {
     SysSelect,
     SysSocket,
     SysStat,
+    SysStatvfs,
     SysTypes,
     SysUtsName,
     SysWait,

libc/src/sys/CMakeLists.txt

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

libc/src/sys/statvfs/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(
+  statvfs
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.statvfs
+)
+
+add_entrypoint_object(
+  fstatvfs
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.fstatvfs
+)

libc/src/sys/statvfs/fstatvfs.h

@@ -0,0 +1,20 @@
+//===-- Implementation header for fstatvfs ----------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SYS_STATVFS_FSTATVFS_H
+#define LLVM_LIBC_SRC_SYS_STATVFS_FSTATVFS_H
+
+#include "llvm-libc-types/struct_statvfs.h"
+
+namespace LIBC_NAMESPACE {
+
+int fstatvfs(int fd, struct statvfs *buf);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_SYS_STATVFS_FSTATVFS_H

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

@@ -0,0 +1,36 @@
+add_header_library(
+  statfs_utils
+  HDRS
+    statfs_utils.h
+  DEPENDS
+    libc.src.errno.errno
+    libc.src.__support.OSUtil.osutil
+    libc.src.__support.common
+    libc.src.__support.CPP.optional
+    libc.include.sys_syscall
+)
+
+add_entrypoint_object(
+  statvfs
+  SRCS
+    statvfs.cpp
+  HDRS
+    ../statvfs.h
+  DEPENDS
+    libc.src.__support.libc_assert
+    libc.include.llvm-libc-types.struct_statvfs
+    .statfs_utils
+)
+
+add_entrypoint_object(
+  fstatvfs
+  SRCS
+    fstatvfs.cpp
+  HDRS
+    ../fstatvfs.h
+  DEPENDS
+    libc.src.__support.libc_assert
+    libc.include.llvm-libc-types.struct_statvfs
+    .statfs_utils
+)
+

libc/src/sys/statvfs/linux/fstatvfs.cpp

@@ -0,0 +1,26 @@
+//===-- Linux implementation of fstatvfs ----------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/sys/statvfs/fstatvfs.h"
+#include "src/__support/common.h"
+#include "src/__support/libc_assert.h"
+#include "src/sys/statvfs/linux/statfs_utils.h"
+
+namespace LIBC_NAMESPACE {
+
+LLVM_LIBC_FUNCTION(int, fstatvfs, (int fd, struct statvfs *buf)) {
+  using namespace statfs_utils;
+  cpp::optional<LinuxStatFs> result = linux_fstatfs(fd);
+  if (result) {
+    LIBC_ASSERT(buf != nullptr);
+    *buf = statfs_to_statvfs(*result);
+  }
+  return result ? 0 : -1;
+}
+
+} // namespace LIBC_NAMESPACE

libc/src/sys/statvfs/linux/statfs_utils.h

@@ -0,0 +1,95 @@
+//===-- Convert Statfs to Statvfs -------------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SYS_STATVFS_LINUX_STATFS_TO_STATVFS_H
+#define LLVM_LIBC_SRC_SYS_STATVFS_LINUX_STATFS_TO_STATVFS_H
+
+#include "llvm-libc-types/struct_statvfs.h"
+#include "src/__support/CPP/optional.h"
+#include "src/__support/OSUtil/syscall.h"
+#include "src/__support/macros/attributes.h"
+#include "src/errno/libc_errno.h"
+#include <asm/statfs.h>
+#include <sys/syscall.h>
+namespace LIBC_NAMESPACE {
+
+namespace statfs_utils {
+#ifdef SYS_statfs64
+using LinuxStatFs = statfs64;
+#else
+using LinuxStatFs = statfs;
+#endif
+
+// Linux kernel set an additional flag to f_flags. Libc should mask it out.
+LIBC_INLINE_VAR constexpr decltype(LinuxStatFs::f_flags) ST_VALID = 0x0020;
+
+LIBC_INLINE cpp::optional<LinuxStatFs> linux_statfs(const char *path) {
+  // The kernel syscall routine checks the validity of the path before filling
+  // the statfs structure. So, it is possible that the result is not initialized
+  // after the syscall. Since the struct is trvial, the compiler will generate
+  // pattern filling for the struct.
+  LinuxStatFs result;
+  // On 32-bit platforms, original statfs cannot handle large file systems.
+  // In such cases, SYS_statfs64 is defined and should be used.
+#ifdef SYS_statfs64
+  int ret = syscall_impl<int>(SYS_statfs64, path, sizeof(result), &result);
+#else
+  int ret = syscall_impl<int>(SYS_statfs, path, &result);
+#endif
+  if (ret < 0) {
+    libc_errno = -ret;
+    return cpp::nullopt;
+  }
+  result.f_flags &= ~ST_VALID;
+  return result;
+}
+
+LIBC_INLINE cpp::optional<LinuxStatFs> linux_fstatfs(int fd) {
+  // The kernel syscall routine checks the validity of the path before filling
+  // the statfs structure. So, it is possible that the result is not initialized
+  // after the syscall. Since the struct is trvial, the compiler will generate
+  // pattern filling for the struct.
+  LinuxStatFs result;
+  // On 32-bit platforms, original fstatfs cannot handle large file systems.
+  // In such cases, SYS_fstatfs64 is defined and should be used.
+#ifdef SYS_fstatfs64
+  int ret = syscall_impl<int>(SYS_fstatfs64, fd, sizeof(result), &result);
+#else
+  int ret = syscall_impl<int>(SYS_fstatfs, fd, &result);
+#endif
+  if (ret < 0) {
+    libc_errno = -ret;
+    return cpp::nullopt;
+  }
+  result.f_flags &= ~ST_VALID;
+  return result;
+}
+
+// must use 'struct' tag to refer to type 'statvfs' in this scope. There will be
+// a function in the same namespace with the same name. For consistency, we use
+// struct prefix for all statvfs/statfs related types.
+LIBC_INLINE struct statvfs statfs_to_statvfs(const LinuxStatFs &in) {
+  struct statvfs out;
+  out.f_bsize = in.f_bsize;
+  out.f_frsize = in.f_frsize;
+  out.f_blocks = in.f_blocks;
+  out.f_bfree = in.f_bfree;
+  out.f_bavail = in.f_bavail;
+  out.f_files = in.f_files;
+  out.f_ffree = in.f_ffree;
+  out.f_favail = in.f_ffree;
+  out.f_fsid = in.f_fsid.val[0] |
+               static_cast<decltype(out.f_fsid)>(in.f_fsid.val[1]) << 32;
+  out.f_flag = in.f_flags;
+  out.f_namemax = in.f_namelen;
+  return out;
+}
+} // namespace statfs_utils
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_SYS_STATVFS_LINUX_STATFS_TO_STATVFS_H