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[PATCH v2] io: Consolidate lockf implementation
- From: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
- To: libc-alpha at sourceware dot org
- Date: Mon, 4 Feb 2019 17:40:49 -0200
- Subject: [PATCH v2] io: Consolidate lockf implementation
Changes from previous version [1]:
* Remove hurd fixes since it was fixed upstream.
* Update test copyright year.
--
With internal fcntl64 internal (commit 06ab719d), it is possible to
consolidate lockf implementation by using the LFS fcntl interface
instead of using arch and system-specific implementations.
For Linux, the i386 implementation is used as generic implementation
by replacing the direct syscall with fcntl64 call. The LFS symbol
alias for default LFS ABI (__OFF_T_MATCHES_OFF64_T) is used to avoid
the duplicate symbol (instead of overriding the implementation with an
empty file).
For Hurd lockf64 semantic is changed: previous generic lockf64
implementation returned EOVERFLOW if LEN input is larger than 32-bit
off_t. However, Hurd fcntl64 implementation for F_GETLK64, F_SETLK64,
and F_SETLKW64 do accept off64_t inputs (__f_setlk accepts only off64_t
inputs). The consolidation thus uses the generic implementation on Hurd
as well and it also fixes a bug on Hurd fcntl for POSIX locks where it
tests for the wrong constant inside the F_GETLK64/F_SETLK64/F_SETLKW64
case switch.
Checked on i686-linux-gnu and x86_64-linux-gnu along with a i686-gnu
build.
* io/Makefile (tests): Add tst-lockf.
* io/lockf.c (lockf): Use __fcntl and only define for
!__OFF_T_MATCHES_OFF64_T.
* io/lockf64.c (__lockf64): Call __fcntl64 and alias to lockf for
__OFF_T_MATCHES_OFF64_T case.
* io/tst-lockf.c: New file.
* sysdeps/mach/hurd/fcntl.c (__libc_fcntl): Fix internal check for
F_GETLK64, F_SETLKW64, and F_SETLK64.
* sysdeps/unix/sysv/linux/i386/lockf64.c: Remove file.
* sysdeps/unix/sysv/linux/arm/lockf64.c: Likewise.
* sysdeps/unix/sysv/linux/m68k/lockf64.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/lockf64.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/lockf64.c: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/lockf64.c: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/lockf64.c: Likewise.
* sysdeps/unix/sysv/linux/sh/lockf64.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/lockf64.c: Likewise.
---
ChangeLog | 20 +++
io/Makefile | 2 +-
io/lockf.c | 54 ++-----
io/lockf64.c | 67 +++------
io/tst-lockf.c | 138 ++++++++++++++++++
sysdeps/unix/sysv/linux/arm/lockf64.c | 1 -
sysdeps/unix/sysv/linux/i386/lockf64.c | 70 ---------
sysdeps/unix/sysv/linux/m68k/lockf64.c | 1 -
sysdeps/unix/sysv/linux/mips/mips32/lockf64.c | 1 -
.../unix/sysv/linux/mips/mips64/n32/lockf64.c | 1 -
.../sysv/linux/powerpc/powerpc32/lockf64.c | 1 -
.../unix/sysv/linux/s390/s390-32/lockf64.c | 1 -
sysdeps/unix/sysv/linux/sh/lockf64.c | 1 -
.../unix/sysv/linux/sparc/sparc32/lockf64.c | 1 -
14 files changed, 197 insertions(+), 162 deletions(-)
create mode 100644 io/tst-lockf.c
delete mode 100644 sysdeps/unix/sysv/linux/arm/lockf64.c
delete mode 100644 sysdeps/unix/sysv/linux/i386/lockf64.c
delete mode 100644 sysdeps/unix/sysv/linux/m68k/lockf64.c
delete mode 100644 sysdeps/unix/sysv/linux/mips/mips32/lockf64.c
delete mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n32/lockf64.c
delete mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc32/lockf64.c
delete mode 100644 sysdeps/unix/sysv/linux/s390/s390-32/lockf64.c
delete mode 100644 sysdeps/unix/sysv/linux/sh/lockf64.c
delete mode 100644 sysdeps/unix/sysv/linux/sparc/sparc32/lockf64.c
[1] https://sourceware.org/ml/libc-alpha/2018-11/msg00676.html
diff --git a/io/Makefile b/io/Makefile
index cfae00bbfb..f2404db041 100644
--- a/io/Makefile
+++ b/io/Makefile
@@ -71,7 +71,7 @@ tests := test-utime test-stat test-stat2 test-lfs tst-getcwd \
tst-mknodat tst-mkfifoat tst-ttyname_r bug-ftw5 \
tst-posix_fallocate tst-posix_fallocate64 \
tst-fts tst-fts-lfs tst-open-tmpfile \
- tst-copy_file_range tst-getcwd-abspath \
+ tst-copy_file_range tst-getcwd-abspath tst-lockf
# This test includes the compat implementation of copy_file_range,
# which uses internal, unexported libc functions.
diff --git a/io/lockf.c b/io/lockf.c
index d07342962e..d40aa885c9 100644
--- a/io/lockf.c
+++ b/io/lockf.c
@@ -15,34 +15,26 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
-/* We need to avoid the header declaration of lockf64, because
- the types don't match lockf and then the compiler will
- complain about the mismatch when we do the alias below. */
-#define lockf64 __renamed_lockf64
+#ifndef __OFF_T_MATCHES_OFF64_T
-#include <fcntl.h>
-
-#undef lockf64
-
-#include <sys/types.h>
#include <unistd.h>
+#include <fcntl.h>
#include <errno.h>
-#include <string.h>
/* lockf is a simplified interface to fcntl's locking facilities. */
-
int
lockf (int fd, int cmd, off_t len)
{
- struct flock fl;
-
- memset ((char *) &fl, '\0', sizeof (fl));
-
/* lockf is always relative to the current file position. */
- fl.l_whence = SEEK_CUR;
- fl.l_start = 0;
- fl.l_len = len;
+ struct flock fl = {
+ .l_type = F_WRLCK,
+ .l_whence = SEEK_CUR,
+ .l_len = len
+ };
+ /* lockf() is a cancellation point but so is fcntl() if F_SETLKW is
+ used. Therefore we don't have to care about cancellation here,
+ the fcntl() function will take care of it. */
switch (cmd)
{
case F_TEST:
@@ -55,31 +47,15 @@ lockf (int fd, int cmd, off_t len)
return 0;
__set_errno (EACCES);
return -1;
-
case F_ULOCK:
fl.l_type = F_UNLCK;
- cmd = F_SETLK;
- break;
+ return __fcntl (fd, F_SETLK, &fl);
case F_LOCK:
- fl.l_type = F_WRLCK;
- cmd = F_SETLKW;
- break;
+ return __fcntl (fd, F_SETLKW, &fl);
case F_TLOCK:
- fl.l_type = F_WRLCK;
- cmd = F_SETLK;
- break;
-
- default:
- __set_errno (EINVAL);
- return -1;
+ return __fcntl (fd, F_SETLK, &fl);
}
-
- /* lockf() is a cancellation point but so is fcntl() if F_SETLKW is
- used. Therefore we don't have to care about cancellation here,
- the fcntl() function will take care of it. */
- return __fcntl (fd, cmd, &fl);
+ __set_errno (EINVAL);
+ return -1;
}
-
-#ifdef __OFF_T_MATCHES_OFF64_T
-weak_alias (lockf, lockf64)
#endif
diff --git a/io/lockf64.c b/io/lockf64.c
index 81b554e8f2..d520f776c1 100644
--- a/io/lockf64.c
+++ b/io/lockf64.c
@@ -15,69 +15,48 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
-#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
-#include <string.h>
-
-/* lockf.c defines lockf64 as an alias if __OFF_T_MATCHES_OFF64_T. */
-#ifndef __OFF_T_MATCHES_OFF64_T
/* lockf is a simplified interface to fcntl's locking facilities. */
-
int
-lockf64 (int fd, int cmd, off64_t len64)
+__lockf64 (int fd, int cmd, off64_t len64)
{
- struct flock fl;
- off_t len = (off_t) len64;
-
- if (len64 != (off64_t) len)
- {
- /* We can't represent the length. */
- __set_errno (EOVERFLOW);
- return -1;
- }
-
- memset ((char *) &fl, '\0', sizeof (fl));
-
/* lockf is always relative to the current file position. */
- fl.l_whence = SEEK_CUR;
- fl.l_start = 0;
- fl.l_len = len;
-
+ struct flock64 fl64 = {
+ .l_type = F_WRLCK,
+ .l_whence = SEEK_CUR,
+ .l_len = len64,
+ };
+
+ /* lockf() is a cancellation point but so is fcntl() if F_SETLKW is
+ used. Therefore we don't have to care about cancellation here,
+ the fcntl() function will take care of it. */
switch (cmd)
{
case F_TEST:
/* Test the lock: return 0 if FD is unlocked or locked by this process;
return -1, set errno to EACCES, if another process holds the lock. */
- fl.l_type = F_RDLCK;
- if (__fcntl (fd, F_GETLK, &fl) < 0)
+ fl64.l_type = F_RDLCK;
+ if (__fcntl (fd, F_GETLK64, &fl64) < 0)
return -1;
- if (fl.l_type == F_UNLCK || fl.l_pid == __getpid ())
- return 0;
+ if (fl64.l_type == F_UNLCK || fl64.l_pid == __getpid ())
+ return 0;
__set_errno (EACCES);
return -1;
-
case F_ULOCK:
- fl.l_type = F_UNLCK;
- cmd = F_SETLK;
- break;
+ fl64.l_type = F_UNLCK;
+ return __fcntl64 (fd, F_SETLK64, &fl64);
case F_LOCK:
- fl.l_type = F_WRLCK;
- cmd = F_SETLKW;
- break;
+ return __fcntl64 (fd, F_SETLKW64, &fl64);
case F_TLOCK:
- fl.l_type = F_WRLCK;
- cmd = F_SETLK;
- break;
-
- default:
- __set_errno (EINVAL);
- return -1;
+ return __fcntl64 (fd, F_SETLK64, &fl64);
}
-
- return __fcntl (fd, cmd, &fl);
+ __set_errno (EINVAL);
+ return -1;
}
-
+weak_alias (__lockf64, lockf64)
+#ifdef __OFF_T_MATCHES_OFF64_T
+weak_alias (lockf64, lockf)
#endif
diff --git a/io/tst-lockf.c b/io/tst-lockf.c
new file mode 100644
index 0000000000..05f8a6a797
--- /dev/null
+++ b/io/tst-lockf.c
@@ -0,0 +1,138 @@
+/* Test POSIX lock on an open file (lockf).
+ Copyright (C) 2019 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License
+ as published by the Free Software Foundation; either version 2
+ of the License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <unistd.h>
+#include <stdint.h>
+#include <errno.h>
+#include <stdio.h>
+
+#include <support/temp_file.h>
+#include <support/capture_subprocess.h>
+#include <support/check.h>
+
+static char *temp_filename;
+static int temp_fd;
+
+static void
+do_prepare (int argc, char **argv)
+{
+ temp_fd = create_temp_file ("tst-lockfd.", &temp_filename);
+ TEST_VERIFY_EXIT (temp_fd != -1);
+}
+#define PREPARE do_prepare
+
+static void
+do_test_child_lockf (void *closure)
+{
+ /* Check if parent has [0, 1024) locked. */
+ TEST_COMPARE (lseek (temp_fd, 0, SEEK_SET), 0);
+ TEST_COMPARE (lockf (temp_fd, F_TLOCK, 1024), -1);
+ TEST_COMPARE (errno, EAGAIN);
+ TEST_COMPARE (lockf (temp_fd, F_TEST, 1024), -1);
+ TEST_COMPARE (errno, EACCES);
+ /* Also Check if parent has last 1024 bytes locked. */
+ TEST_COMPARE (lseek (temp_fd, INT32_MAX-1024, SEEK_SET), INT32_MAX-1024);
+ TEST_COMPARE (lockf (temp_fd, F_TEST, 1024), -1);
+
+ /* And try to lock [1024, 2048). */
+ TEST_COMPARE (lseek (temp_fd, 1024, SEEK_SET), 1024);
+ TEST_COMPARE (lockf (temp_fd, F_LOCK, 1024), 0);
+
+ /* Check if non-LFS interface cap access to 32-bif off_t. */
+ TEST_COMPARE (lseek64 (temp_fd, (off64_t)INT32_MAX, SEEK_SET),
+ (off64_t)INT32_MAX);
+ TEST_COMPARE (lockf64 (temp_fd, F_TEST, 1024), 0);
+}
+
+static void
+do_test_child_lockf64 (void *closure)
+{
+ /* Check if parent has [0, 1024) locked. */
+ TEST_COMPARE (lseek64 (temp_fd, 0, SEEK_SET), 0);
+ TEST_COMPARE (lockf64 (temp_fd, F_TLOCK, 1024), -1);
+ TEST_COMPARE (errno, EAGAIN);
+ TEST_COMPARE (lockf64 (temp_fd, F_TEST, 1024), -1);
+ TEST_COMPARE (errno, EACCES);
+ /* Also Check if parent has last 1024 bytes locked. */
+ TEST_COMPARE (lseek64 (temp_fd, INT32_MAX-1024, SEEK_SET), INT32_MAX-1024);
+ TEST_COMPARE (lockf64 (temp_fd, F_TEST, 1024), -1);
+
+ /* And try to lock [1024, 2048). */
+ TEST_COMPARE (lseek64 (temp_fd, 1024, SEEK_SET), 1024);
+ TEST_COMPARE (lockf64 (temp_fd, F_LOCK, 1024), 0);
+
+ /* And also [INT32_MAX, INT32_MAX+1024). */
+ {
+ off64_t off = (off64_t)INT32_MAX;
+ TEST_COMPARE (lseek64 (temp_fd, off, SEEK_SET), off);
+ TEST_COMPARE (lockf64 (temp_fd, F_LOCK, 1024), 0);
+ }
+
+ /* Check if [INT32_MAX+1024, INT64_MAX) is locked. */
+ {
+ off64_t off = (off64_t)INT32_MAX+1024;
+ TEST_COMPARE (lseek64 (temp_fd, off, SEEK_SET), off);
+ TEST_COMPARE (lockf64 (temp_fd, F_TLOCK, 1024), -1);
+ TEST_COMPARE (errno, EAGAIN);
+ TEST_COMPARE (lockf64 (temp_fd, F_TEST, 1024), -1);
+ TEST_COMPARE (errno, EACCES);
+ }
+}
+
+static int
+do_test (void)
+{
+ /* Basic tests to check if a lock can be obtained and checked. */
+ TEST_COMPARE (lockf (temp_fd, F_LOCK, 1024), 0);
+ TEST_COMPARE (lockf (temp_fd, F_LOCK, INT32_MAX), 0);
+ TEST_COMPARE (lockf (temp_fd, F_TLOCK, 1024), 0);
+ TEST_COMPARE (lockf (temp_fd, F_TEST, 1024), 0);
+ TEST_COMPARE (lseek (temp_fd, 1024, SEEK_SET), 1024);
+ TEST_COMPARE (lockf (temp_fd, F_ULOCK, 1024), 0);
+ /* Parent process should have ([0, 1024), [2048, INT32_MAX)) ranges locked. */
+
+ {
+ struct support_capture_subprocess result;
+ result = support_capture_subprocess (do_test_child_lockf, NULL);
+ support_capture_subprocess_check (&result, "lockf", 0, sc_allow_none);
+ }
+
+ if (sizeof (off_t) != sizeof (off64_t))
+ {
+ /* Check if previously locked regions with LFS symbol. */
+ TEST_COMPARE (lseek (temp_fd, 0, SEEK_SET), 0);
+ TEST_COMPARE (lockf64 (temp_fd, F_LOCK, 1024), 0);
+ TEST_COMPARE (lockf64 (temp_fd, F_TLOCK, 1024), 0);
+ TEST_COMPARE (lockf64 (temp_fd, F_TEST, 1024), 0);
+ /* Lock region [INT32_MAX+1024, INT64_MAX). */
+ off64_t off = (off64_t)INT32_MAX + 1024;
+ TEST_COMPARE (lseek64 (temp_fd, off, SEEK_SET), off);
+ TEST_COMPARE (lockf64 (temp_fd, F_LOCK, 1024), 0);
+ /* Parent process should have ([0, 1024), [2048, INT32_MAX),
+ [INT32_MAX+1024, INT64_MAX)) ranges locked. */
+
+ {
+ struct support_capture_subprocess result;
+ result = support_capture_subprocess (do_test_child_lockf64, NULL);
+ support_capture_subprocess_check (&result, "lockf", 0, sc_allow_none);
+ }
+ }
+
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/unix/sysv/linux/arm/lockf64.c b/sysdeps/unix/sysv/linux/arm/lockf64.c
deleted file mode 100644
index a88f5a784a..0000000000
--- a/sysdeps/unix/sysv/linux/arm/lockf64.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/unix/sysv/linux/i386/lockf64.c>
diff --git a/sysdeps/unix/sysv/linux/i386/lockf64.c b/sysdeps/unix/sysv/linux/i386/lockf64.c
deleted file mode 100644
index 7c8631112f..0000000000
--- a/sysdeps/unix/sysv/linux/i386/lockf64.c
+++ /dev/null
@@ -1,70 +0,0 @@
-/* Copyright (C) 1994-2019 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <http://www.gnu.org/licenses/>. */
-
-#include <sys/types.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <errno.h>
-#include <string.h>
-#include <sysdep.h>
-
-/* lockf is a simplified interface to fcntl's locking facilities. */
-
-int
-lockf64 (int fd, int cmd, off64_t len64)
-{
- struct flock64 fl64;
- int cmd64;
- int result;
-
- memset ((char *) &fl64, '\0', sizeof (fl64));
- fl64.l_whence = SEEK_CUR;
- fl64.l_start = 0;
- fl64.l_len = len64;
-
- switch (cmd)
- {
- case F_TEST:
- /* Test the lock: return 0 if FD is unlocked or locked by this process;
- return -1, set errno to EACCES, if another process holds the lock. */
- fl64.l_type = F_RDLCK;
- INTERNAL_SYSCALL_DECL (err);
- result = INTERNAL_SYSCALL (fcntl64, err, 3, fd, F_GETLK64, &fl64);
- if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, err)))
- return INLINE_SYSCALL_ERROR_RETURN_VALUE (INTERNAL_SYSCALL_ERRNO (result,
- err));
- if (fl64.l_type == F_UNLCK || fl64.l_pid == __getpid ())
- return 0;
- return INLINE_SYSCALL_ERROR_RETURN_VALUE (EACCES);
- case F_ULOCK:
- fl64.l_type = F_UNLCK;
- cmd64 = F_SETLK64;
- break;
- case F_LOCK:
- fl64.l_type = F_WRLCK;
- cmd64 = F_SETLKW64;
- break;
- case F_TLOCK:
- fl64.l_type = F_WRLCK;
- cmd64 = F_SETLK64;
- break;
-
- default:
- return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
- }
- return INLINE_SYSCALL (fcntl64, 3, fd, cmd64, &fl64);
-}
diff --git a/sysdeps/unix/sysv/linux/m68k/lockf64.c b/sysdeps/unix/sysv/linux/m68k/lockf64.c
deleted file mode 100644
index a88f5a784a..0000000000
--- a/sysdeps/unix/sysv/linux/m68k/lockf64.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/unix/sysv/linux/i386/lockf64.c>
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/lockf64.c b/sysdeps/unix/sysv/linux/mips/mips32/lockf64.c
deleted file mode 100644
index a88f5a784a..0000000000
--- a/sysdeps/unix/sysv/linux/mips/mips32/lockf64.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/unix/sysv/linux/i386/lockf64.c>
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/lockf64.c b/sysdeps/unix/sysv/linux/mips/mips64/n32/lockf64.c
deleted file mode 100644
index a88f5a784a..0000000000
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/lockf64.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/unix/sysv/linux/i386/lockf64.c>
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/lockf64.c b/sysdeps/unix/sysv/linux/powerpc/powerpc32/lockf64.c
deleted file mode 100644
index a88f5a784a..0000000000
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/lockf64.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/unix/sysv/linux/i386/lockf64.c>
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/lockf64.c b/sysdeps/unix/sysv/linux/s390/s390-32/lockf64.c
deleted file mode 100644
index a88f5a784a..0000000000
--- a/sysdeps/unix/sysv/linux/s390/s390-32/lockf64.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/unix/sysv/linux/i386/lockf64.c>
diff --git a/sysdeps/unix/sysv/linux/sh/lockf64.c b/sysdeps/unix/sysv/linux/sh/lockf64.c
deleted file mode 100644
index a88f5a784a..0000000000
--- a/sysdeps/unix/sysv/linux/sh/lockf64.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/unix/sysv/linux/i386/lockf64.c>
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/lockf64.c b/sysdeps/unix/sysv/linux/sparc/sparc32/lockf64.c
deleted file mode 100644
index a88f5a784a..0000000000
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/lockf64.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/unix/sysv/linux/i386/lockf64.c>
--
2.17.1