1
linux/fs
Ulrich Drepper 45c9b11a1d [PATCH] Implement AT_SYMLINK_FOLLOW flag for linkat
When the linkat() syscall was added the flag parameter was added in the
last minute but it wasn't used so far.  The following patch should change
that.  My tests show that this is all that's needed.

If OLDNAME is a symlink setting the flag causes linkat to follow the
symlink and create a hardlink with the target.  This is actually the
behavior POSIX demands for link() as well but Linux wisely does not do
this.  With this flag (which will most likely be in the next POSIX
revision) the programmer can choose the behavior, defaulting to the safe
variant.  As a side effect it is now possible to implement a
POSIX-compliant link(2) function for those who are interested.

  touch file
  ln -s file symlink

  linkat(fd, "symlink", fd, "newlink", 0)
    -> newlink is hardlink of symlink

  linkat(fd, "symlink", fd, "newlink", AT_SYMLINK_FOLLOW)
    -> newlink is hardlink of file

The value of AT_SYMLINK_FOLLOW is determined by the definition we already
use in glibc.

Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 10:01:22 -07:00
..
9p [PATCH] Remove needless checks in fs/9p/vfs_inode.c 2006-06-25 10:01:20 -07:00
adfs [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
affs [PATCH] fix %s in affs_fill_super() 2006-06-25 10:01:22 -07:00
afs [PATCH] read_mapping_page for address space 2006-06-23 07:43:02 -07:00
autofs [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
autofs4 [PATCH] autofs4: need to invalidate children on tree mount expire 2006-06-25 10:01:18 -07:00
befs [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
bfs [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
cifs [PATCH] vfs: add lock owner argument to flush operation 2006-06-23 07:43:02 -07:00
coda [PATCH] vfs: add lock owner argument to flush operation 2006-06-23 07:43:02 -07:00
configfs [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
cramfs [PATCH] read_mapping_page for address space 2006-06-23 07:43:02 -07:00
debugfs [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
devfs [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
devpts [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
efs [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
exportfs [PATCH] NFS server subtree_check returns dubious value 2006-05-21 12:59:16 -07:00
ext2 [PATCH] Make EXT2_DEBUG work again 2006-06-25 10:01:12 -07:00
ext3 [PATCH] ext3: cleanup dead code in ext3_add_entry() 2006-06-25 10:01:15 -07:00
fat [PATCH] fs/fat/misc.c: unexport fat_sync_bhs 2006-06-23 07:43:03 -07:00
freevxfs [PATCH] fs/freevxfs: cleanup of spelling errors 2006-06-25 10:01:01 -07:00
fuse [PATCH] fuse: scramble lock owner ID 2006-06-25 10:01:20 -07:00
hfs [PATCH] read_mapping_page for address space 2006-06-23 07:43:02 -07:00
hfsplus [PATCH] read_mapping_page for address space 2006-06-23 07:43:02 -07:00
hostfs [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
hpfs [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
hppfs [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
hugetlbfs [PATCH] tightening hugetlb strict accounting 2006-06-23 07:42:48 -07:00
isofs [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
jbd [PATCH] ext3: fix memory leak when the journal file is corrupted 2006-06-25 10:01:07 -07:00
jffs [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
jffs2 [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
jfs [PATCH] read_mapping_page for address space 2006-06-23 07:43:02 -07:00
lockd NFS: make 2 functions static 2006-04-19 12:43:47 -04:00
minix [PATCH] read_mapping_page for address space 2006-06-23 07:43:02 -07:00
msdos [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
ncpfs [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
nfs [PATCH] vfs: add lock owner argument to flush operation 2006-06-23 07:43:02 -07:00
nfs_common
nfsd [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
nls
ntfs [PATCH] Prepare for __copy_from_user_inatomic to not zero missed bytes 2006-06-25 10:01:09 -07:00
ocfs2 [PATCH] read_mapping_page for address space 2006-06-23 07:43:02 -07:00
openpromfs [PATCH] openpromfs: factorize out 2006-06-25 10:01:05 -07:00
partitions [PATCH] make kernel warn about incorrectly sized partitions 2006-06-23 07:43:09 -07:00
proc [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
qnx4 [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
ramfs [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
reiserfs [PATCH] read_mapping_page for address space 2006-06-23 07:43:02 -07:00
romfs [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
smbfs [PATCH] kthread: convert smbiod 2006-06-25 10:01:21 -07:00
sysfs [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
sysv [PATCH] read_mapping_page for address space 2006-06-23 07:43:02 -07:00
udf [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
ufs [PATCH] fs/ufs/inode.c: make 2 functions static 2006-06-25 10:01:04 -07:00
vfat [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
xfs [PATCH] for_each_possible_cpu: xfs 2006-06-23 07:42:45 -07:00
aio.c [PATCH] list: use list_replace_init() instead of list_splice_init() 2006-06-23 07:43:07 -07:00
attr.c
bad_inode.c [PATCH] Make most file operations structs in fs/ const 2006-03-28 09:16:06 -08:00
binfmt_aout.c
binfmt_elf_fdpic.c [PATCH] frv: binfmt_elf_fdpic __user annotations 2006-06-23 07:42:54 -07:00
binfmt_elf.c [PATCH] binflt_elf: remove more casts 2006-06-23 07:43:05 -07:00
binfmt_em86.c
binfmt_flat.c [PATCH] binfmt_flat: don't check for EMFILE 2006-05-21 12:59:17 -07:00
binfmt_misc.c [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
binfmt_script.c
binfmt_som.c
bio.c [PATCH] Fix missing ret assignment in __bio_map_user() error path 2006-06-17 10:52:12 -07:00
block_dev.c [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
buffer.c [PATCH] Kill PF_SYNCWRITE flag 2006-06-23 17:10:39 +02:00
char_dev.c [PATCH] Simplify proc/devices and fix early termination regression 2006-03-31 12:18:53 -08:00
compat_ioctl.c
compat.c [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
dcache.c [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
dcookies.c
direct-io.c [PATCH] Kill PF_SYNCWRITE flag 2006-06-23 17:10:39 +02:00
dnotify.c
dquot.c BUG_ON() Conversion in fs/dquot.c 2006-04-02 13:36:13 +02:00
drop_caches.c
eventpoll.c [PATCH] epoll: use unlocked wqueue operations 2006-06-25 10:01:13 -07:00
exec.c [PATCH] remove steal_locks() 2006-06-22 15:05:57 -07:00
fcntl.c BUG_ON() Conversion in fs/fcntl.c 2006-04-02 13:37:19 +02:00
fifo.c [PATCH] pipe.c/fifo.c code cleanups 2006-04-11 13:53:33 +02:00
file_table.c [PATCH] percpu counter data type changes to suppport more than 2**31 ext3 free blocks counter 2006-06-23 07:43:06 -07:00
file.c [PATCH] for_each_possible_cpu: fixes for generic part 2006-03-28 09:16:05 -08:00
filesystems.c
fs-writeback.c [PATCH] Kill PF_SYNCWRITE flag 2006-06-23 17:10:39 +02:00
inode.c BUG_ON() Conversion in fs/inode.c 2006-04-02 13:38:18 +02:00
inotify_user.c [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
inotify.c [PATCH] inotify (4/5): allow watch removal from event handler 2006-06-20 05:25:19 -04:00
ioctl.c
ioprio.c [PATCH] lsm: add task_setioprio hook 2006-06-23 07:42:53 -07:00
Kconfig [PATCH] Make procfs obligatory except under CONFIG_EMBEDDED 2006-06-25 10:01:11 -07:00
Kconfig.binfmt
libfs.c [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
locks.c [PATCH] fs/locks.c: make posix_locks_deadlock() static 2006-06-23 07:43:03 -07:00
Makefile [PATCH] inotify (1/5): split kernel API from userspace support 2006-06-20 05:25:17 -04:00
mbcache.c [PATCH] Typo fixes 2006-03-28 09:16:08 -08:00
mpage.c [PATCH] writeback: fix range handling 2006-06-23 07:42:49 -07:00
namei.c [PATCH] Implement AT_SYMLINK_FOLLOW flag for linkat 2006-06-25 10:01:22 -07:00
namespace.c [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
nfsctl.c
open.c [PATCH] ftruncate does not always update m/ctime 2006-06-25 10:01:15 -07:00
pipe.c [PATCH] VFS: Permit filesystem to override root dentry on mount 2006-06-23 07:42:45 -07:00
pnode.c
pnode.h
posix_acl.c
quota_v1.c
quota_v2.c
quota.c
read_write.c [PATCH] splice: unlikely() optimizations 2006-04-11 13:56:09 +02:00
readdir.c
select.c [PATCH] fs: sys_poll with timeout -1 bug fix 2006-06-25 10:01:22 -07:00
seq_file.c
splice.c [PATCH] splice: retrieve mapping after locking the page 2006-06-23 17:10:39 +02:00
stat.c [PATCH] powerpc: Wire up *at syscalls 2006-04-28 21:04:59 +10:00
super.c [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry 2006-06-23 07:42:45 -07:00
sync.c [PATCH] writeback: fix range handling 2006-06-23 07:42:49 -07:00
xattr_acl.c
xattr.c [PATCH] log more info for directory entry change events 2006-06-20 05:25:28 -04:00