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io: Consolidate lockf implementation

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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.
This commit is contained in:
Adhemerval Zanella
2018-11-21 11:41:05 +00:00
parent bc10e22c90
commit e442e40de5
14 changed files with 194 additions and 161 deletions
Download Patch File Download Diff File Expand all files Collapse all files

65
io/lockf64.c
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@ -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