From e442e40de5646e93bf31ace3e0c5159085a7259b Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Wed, 21 Nov 2018 11:41:05 +0000 Subject: io: Consolidate lockf implementation 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). 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/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. --- io/Makefile | 2 +- io/lockf.c | 54 +++++++--------------- io/lockf64.c | 67 ++++++++++------------------ io/tst-lockf.c | 138 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 177 insertions(+), 84 deletions(-) create mode 100644 io/tst-lockf.c (limited to 'io') diff --git a/io/Makefile b/io/Makefile index cfae00b..f2404db 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 d073429..d40aa88 100644 --- a/io/lockf.c +++ b/io/lockf.c @@ -15,34 +15,26 @@ License along with the GNU C Library; if not, see . */ -/* 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 - -#undef lockf64 - -#include #include +#include #include -#include /* 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 81b554e..d520f77 100644 --- a/io/lockf64.c +++ b/io/lockf64.c @@ -15,69 +15,48 @@ License along with the GNU C Library; if not, see . */ -#include #include #include #include -#include - -/* 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 0000000..5ed2294 --- /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 . +*/ + +#include +#include +#include +#include + +#include +#include +#include + +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 -- cgit v1.1