linux/fs
Ulrich Drepper 22d2b35b20 F_DUPFD_CLOEXEC implementation
One more small change to extend the availability of creation of file
descriptors with FD_CLOEXEC set.  Adding a new command to fcntl() requires
no new system call and the overall impact on code size if minimal.

If this patch gets accepted we will also add this change to the next
revision of the POSIX spec.

To test the patch, use the following little program.  Adjust the value of
F_DUPFD_CLOEXEC appropriately.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#ifndef F_DUPFD_CLOEXEC
# define F_DUPFD_CLOEXEC 12
#endif

int
main (int argc, char *argv[])
{
  if  (argc > 1)
    {
      if (fcntl (3, F_GETFD) == 0)
	{
	  puts ("descriptor not closed");
	  exit (1);
	}
      if (errno != EBADF)
	{
	  puts ("error not EBADF");
	  exit (1);
	}

      exit (0);
    }
  int fd = fcntl (STDOUT_FILENO, F_DUPFD_CLOEXEC, 0);
  if (fd == -1 && errno == EINVAL)
    {
      puts ("F_DUPFD_CLOEXEC not supported");
      return 0;
    }
  if (fd != 3)
    {
      puts ("program called with descriptors other than 0,1,2");
      return 1;
    }

  execl ("/proc/self/exe", "/proc/self/exe", "1", NULL);
  puts ("execl failed");
  return 1;
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:43:01 -07:00
..
9p 9PFS: clean up explicit check for mandatory locks 2007-10-09 18:32:46 -04:00
adfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
affs fs: mark nibblemap const 2007-10-17 08:42:47 -07:00
afs KEYS: Make request_key() and co fundamentally asynchronous 2007-10-17 08:42:57 -07:00
autofs
autofs4 fs/autofs4/inode.c: kmalloc + memset conversion to kzalloc 2007-10-17 08:42:50 -07:00
befs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
bfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
cifs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
coda Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
configfs mm: bdi init hooks 2007-10-17 08:42:45 -07:00
cramfs cramfs: error message about endianess 2007-10-17 08:42:53 -07:00
debugfs docbook: fix filesystems content 2007-10-15 17:56:36 -07:00
devpts
dlm menuconfig: transform NLS and DLM menus 2007-10-17 08:43:00 -07:00
ecryptfs Clean up duplicate includes in fs/ecryptfs/ 2007-10-17 08:42:48 -07:00
efs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
exportfs knfsd: exportfs: split out reconnecting a dentry from find_exported_dentry 2007-07-17 10:23:06 -07:00
ext2 ext2/4: use is_power_of_2() 2007-10-17 08:42:53 -07:00
ext3 ext3: remove #ifdef CONFIG_EXT3_INDEX 2007-10-17 08:43:01 -07:00
ext4 Fix f_version type: should be u64 instead of unsigned long 2007-10-17 08:42:53 -07:00
fat Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
freevxfs mm: Remove slab destructors from kmem_cache_create(). 2007-07-20 10:11:58 +09:00
fuse Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
gfs2 fs: correct SuS compliance for open of large file without options 2007-10-17 08:43:01 -07:00
hfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
hfsplus Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
hostfs uml: fix hostfs style 2007-10-16 09:43:07 -07:00
hpfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
hppfs
hugetlbfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
isofs fs/isofs/namei.c: Remove uninitialized local vars warning 2007-10-17 08:42:58 -07:00
jbd Group short-lived and reclaimable kernel allocations 2007-10-16 09:43:00 -07:00
jbd2 mm: Remove slab destructors from kmem_cache_create(). 2007-07-20 10:11:58 +09:00
jffs2 Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
jfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
lockd NFS/SUNRPC: use transport protocol naming 2007-10-09 17:17:53 -04:00
minix limit minixfs printks on corrupted dir i_size 2007-10-17 08:42:53 -07:00
msdos
ncpfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
nfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
nfs_common
nfsd fs/nfsd/export.c: make 3 functions static 2007-10-16 09:43:10 -07:00
nls menuconfig: transform NLS and DLM menus 2007-10-17 08:43:00 -07:00
ntfs fs: correct SuS compliance for open of large file without options 2007-10-17 08:43:01 -07:00
ocfs2 Fix f_version type: should be u64 instead of unsigned long 2007-10-17 08:42:53 -07:00
openpromfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
partitions fs/partitions/sun.c endianness annotations 2007-10-14 12:41:51 -07:00
proc Don't truncate /proc/PID/environ at 4096 characters 2007-10-17 08:43:00 -07:00
qnx4 Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
ramfs Remove valueless definition of hard-selected RAMFS option 2007-10-17 08:42:56 -07:00
reiserfs reiserfs: workaround for dead loop in finish_unfinished 2007-10-17 08:42:58 -07:00
romfs fs/romfs/inode.c: trivial improvements 2007-10-17 08:42:47 -07:00
smbfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
sysfs spin_lock_unlocked cleanups 2007-10-17 08:43:01 -07:00
sysv Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
udf fs/udf/balloc.c: mark a variable as uninitialized_var() 2007-10-17 08:43:00 -07:00
ufs ufs: Fix mount check in ufs_fill_super() 2007-10-17 08:42:51 -07:00
vfat
xfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
aio.c aio: account I/O wait time properly 2007-10-17 08:42:53 -07:00
anon_inodes.c anon-inodes use open coded atomic_inc for the shared inode 2007-10-17 08:43:00 -07:00
attr.c Introduce is_owner_or_cap() to wrap CAP_FOWNER use with fsuid check 2007-07-17 12:00:03 -07:00
bad_inode.c
binfmt_aout.c core_pattern: ignore RLIMIT_CORE if core_pattern is a pipe 2007-10-17 08:42:50 -07:00
binfmt_elf_fdpic.c core_pattern: ignore RLIMIT_CORE if core_pattern is a pipe 2007-10-17 08:42:50 -07:00
binfmt_elf.c Break ELF_PLATFORM and stack pointer randomization dependency 2007-10-17 08:43:01 -07:00
binfmt_em86.c
binfmt_flat.c binfmt_flat: warning fixes 2007-10-17 08:42:54 -07:00
binfmt_misc.c mm: variable length argument support 2007-07-19 10:04:45 -07:00
binfmt_script.c mm: variable length argument support 2007-07-19 10:04:45 -07:00
binfmt_som.c core_pattern: ignore RLIMIT_CORE if core_pattern is a pipe 2007-10-17 08:42:50 -07:00
bio.c bio: make freeing of ->bi_io_vec conditional in bio_free() 2007-10-16 11:03:52 +02:00
block_dev.c Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
buffer.c mm: count reclaimable pages per BDI 2007-10-17 08:42:45 -07:00
char_dev.c mm: bdi init hooks 2007-10-17 08:42:45 -07:00
compat_ioctl.c Clean up duplicate includes in fs/ 2007-10-17 08:42:48 -07:00
compat.c mm: variable length argument support 2007-07-19 10:04:45 -07:00
dcache.c vfs: use the predefined d_unhashed inline function instead 2007-10-17 08:43:00 -07:00
dcookies.c Remove fs.h from mm.h 2007-07-29 17:09:29 -07:00
direct-io.c remove ZERO_PAGE 2007-10-16 09:42:53 -07:00
dnotify.c mm: Remove slab destructors from kmem_cache_create(). 2007-07-20 10:11:58 +09:00
dquot.c quota: send messages via netlink 2007-10-17 08:42:56 -07:00
drop_caches.c invalidate_mapping_pages(): add cond_resched 2007-07-16 09:05:36 -07:00
eventfd.c
eventpoll.c mm: Remove slab destructors from kmem_cache_create(). 2007-07-20 10:11:58 +09:00
exec.c exec: RT sub-thread can livelock and monopolize CPU on exec 2007-10-17 08:42:54 -07:00
fcntl.c F_DUPFD_CLOEXEC implementation 2007-10-17 08:43:01 -07:00
fifo.c
file_table.c fs: use kmem_cache_zalloc instead 2007-10-17 08:42:48 -07:00
file.c
filesystems.c
fs-writeback.c Fix warnings with !CONFIG_BLOCK 2007-10-10 09:25:57 +02:00
generic_acl.c Introduce is_owner_or_cap() to wrap CAP_FOWNER use with fsuid check 2007-07-17 12:00:03 -07:00
inode.c fs: remove the unused mempages parameter 2007-10-17 08:42:49 -07:00
inotify_user.c change inotifyfs magic as the same magic is used for futexfs 2007-10-17 08:43:00 -07:00
inotify.c
internal.h
ioctl.c drop obsolete sys_ioctl export 2007-07-16 09:05:48 -07:00
ioprio.c
Kconfig menuconfig: transform Network Filesystems menu 2007-10-17 08:43:00 -07:00
Kconfig.binfmt
libfs.c make fs/libfs.c:simple_commit_write() static 2007-10-17 08:42:53 -07:00
locks.c Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
Makefile Remove valueless definition of hard-selected RAMFS option 2007-10-17 08:42:56 -07:00
mbcache.c mm: Remove slab destructors from kmem_cache_create(). 2007-07-20 10:11:58 +09:00
mpage.c mm: buffered write cleanup 2007-10-16 09:42:54 -07:00
namei.c fix execute checking in permission() 2007-10-17 08:42:52 -07:00
namespace.c fs: remove the unused mempages parameter 2007-10-17 08:42:49 -07:00
nfsctl.c nfsctl: use vfs_path_lookup 2007-07-19 10:04:45 -07:00
no-block.c
open.c fs: correct SuS compliance for open of large file without options 2007-10-17 08:43:01 -07:00
pipe.c sched: affine sync wakeups 2007-10-15 17:00:19 +02:00
pnode.c
pnode.h
posix_acl.c
quota_v1.c
quota_v2.c
quota.c [IA64] Fix build failure in fs/quota.c 2007-07-27 15:40:13 -07:00
read_write.c Cleanup macros for distinguishing mandatory locks 2007-10-09 18:32:46 -04:00
read_write.h
readdir.c
select.c Use ERESTART_RESTARTBLOCK if poll() is interrupted by a signal 2007-10-17 08:42:53 -07:00
seq_file.c [FS] seq_file: Introduce the seq_open_private() 2007-10-10 16:55:33 -07:00
signalfd.c rename signalfd_siginfo fields 2007-10-17 08:43:01 -07:00
splice.c Merge branch 'for-linus' of git://git.kernel.dk/data/git/linux-2.6-block 2007-10-16 10:09:16 -07:00
stack.c
stat.c
super.c hugetlbfs: handle empty options string 2007-07-16 09:05:46 -07:00
sync.c
timerfd.c make timerfd return a u64 and fix the __put_user 2007-07-26 11:35:17 -07:00
utimes.c VFS: check nanoseconds in utimensat 2007-10-17 08:42:52 -07:00
xattr_acl.c
xattr.c Introduce is_owner_or_cap() to wrap CAP_FOWNER use with fsuid check 2007-07-17 12:00:03 -07:00