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| author | David Howells <dhowells@redhat.com> | 2015-06-18 14:32:31 +0100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2015-06-19 03:19:32 -0400 |
| commit | 4bacc9c9234c7c8eec44f5ed4e960d9f96fa0f01 (patch) | |
| tree | 1ecac38332d4e8cf5370627f1214a1d7c5ff7529 /fs/internal.h | |
| parent | f25801ee4680ef1db21e15c112e6e5fe3ffe8da5 (diff) | |
| download | op-kernel-dev-4bacc9c9234c7c8eec44f5ed4e960d9f96fa0f01.zip op-kernel-dev-4bacc9c9234c7c8eec44f5ed4e960d9f96fa0f01.tar.gz | |
overlayfs: Make f_path always point to the overlay and f_inode to the underlay
Make file->f_path always point to the overlay dentry so that the path in
/proc/pid/fd is correct and to ensure that label-based LSMs have access to the
overlay as well as the underlay (path-based LSMs probably don't need it).
Using my union testsuite to set things up, before the patch I see:
[root@andromeda union-testsuite]# bash 5</mnt/a/foo107
[root@andromeda union-testsuite]# ls -l /proc/$$/fd/
...
lr-x------. 1 root root 64 Jun 5 14:38 5 -> /a/foo107
[root@andromeda union-testsuite]# stat /mnt/a/foo107
...
Device: 23h/35d Inode: 13381 Links: 1
...
[root@andromeda union-testsuite]# stat -L /proc/$$/fd/5
...
Device: 23h/35d Inode: 13381 Links: 1
...
After the patch:
[root@andromeda union-testsuite]# bash 5</mnt/a/foo107
[root@andromeda union-testsuite]# ls -l /proc/$$/fd/
...
lr-x------. 1 root root 64 Jun 5 14:22 5 -> /mnt/a/foo107
[root@andromeda union-testsuite]# stat /mnt/a/foo107
...
Device: 23h/35d Inode: 40346 Links: 1
...
[root@andromeda union-testsuite]# stat -L /proc/$$/fd/5
...
Device: 23h/35d Inode: 40346 Links: 1
...
Note the change in where /proc/$$/fd/5 points to in the ls command. It was
pointing to /a/foo107 (which doesn't exist) and now points to /mnt/a/foo107
(which is correct).
The inode accessed, however, is the lower layer. The union layer is on device
25h/37d and the upper layer on 24h/36d.
Signed-off-by: David Howells <dhowells@redhat.com>
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 01dce1d..4d5af58 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -107,6 +107,7 @@ extern struct file *do_file_open_root(struct dentry *, struct vfsmount *, extern long do_handle_open(int mountdirfd, struct file_handle __user *ufh, int open_flag); extern int open_check_o_direct(struct file *f); +extern int vfs_open(const struct path *, struct file *, const struct cred *); /* * inode.c |
