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| author | Al Viro <viro@zeniv.linux.org.uk> | 2018-11-05 17:40:30 +0000 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2019-03-20 18:49:06 -0400 |
| commit | a07b20004793d8926f78d63eb5980559f7813404 (patch) | |
| tree | 08f7516cbd8ef036fac64b225fd480c2bec3758f /fs/internal.h | |
| parent | 9e98c678c2d6ae3a17cb2de55d17f69dddaa231b (diff) | |
| download | linux-a07b20004793d8926f78d63eb5980559f7813404.tar.bz2 | |
vfs: syscall: Add open_tree(2) to reference or clone a mount
open_tree(dfd, pathname, flags)
Returns an O_PATH-opened file descriptor or an error.
dfd and pathname specify the location to open, in usual
fashion (see e.g. fstatat(2)). flags should be an OR of
some of the following:
* AT_PATH_EMPTY, AT_NO_AUTOMOUNT, AT_SYMLINK_NOFOLLOW -
same meanings as usual
* OPEN_TREE_CLOEXEC - make the resulting descriptor
close-on-exec
* OPEN_TREE_CLONE or OPEN_TREE_CLONE | AT_RECURSIVE -
instead of opening the location in question, create a detached
mount tree matching the subtree rooted at location specified by
dfd/pathname. With AT_RECURSIVE the entire subtree is cloned,
without it - only the part within in the mount containing the
location in question. In other words, the same as mount --rbind
or mount --bind would've taken. The detached tree will be
dissolved on the final close of obtained file. Creation of such
detached trees requires the same capabilities as doing mount --bind.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-api@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/internal.h')
| -rw-r--r-- | fs/internal.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/internal.h b/fs/internal.h index 6a8b71643af4..f3a027c44758 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -94,6 +94,7 @@ extern int __mnt_want_write_file(struct file *); extern void __mnt_drop_write(struct vfsmount *); extern void __mnt_drop_write_file(struct file *); +extern void dissolve_on_fput(struct vfsmount *); /* * fs_struct.c */ |