diff options
| author | Alexander Larsson <alexl@redhat.com> | 2023-08-23 16:33:42 +0200 |
|---|---|---|
| committer | Amir Goldstein <amir73il@gmail.com> | 2023-10-31 00:12:59 +0200 |
| commit | bc8df7a3dc035903426a17ea3027f55817de13a8 (patch) | |
| tree | 7a10810e897acf2f76f601d52214d3b12fffbdb5 /fs/overlayfs/super.c | |
| parent | dad02fad84cbce30f317b69a4f2391f90045f79d (diff) | |
ovl: Add an alternative type of whiteout
An xattr whiteout (called "xwhiteout" in the code) is a reguar file of
zero size with the "overlay.whiteout" xattr set. A file like this in a
directory with the "overlay.whiteouts" xattrs set will be treated the
same way as a regular whiteout.
The "overlay.whiteouts" directory xattr is used in order to
efficiently handle overlay checks in readdir(), as we only need to
checks xattrs in affected directories.
The advantage of this kind of whiteout is that they can be escaped
using the standard overlay xattr escaping mechanism. So, a file with a
"overlay.overlay.whiteout" xattr would be unescaped to
"overlay.whiteout", which could then be consumed by another overlayfs
as a whiteout.
Overlayfs itself doesn't create whiteouts like this, but a userspace
mechanism could use this alternative mechanism to convert images that
may contain whiteouts to be used with overlayfs.
To work as a whiteout for both regular overlayfs mounts as well as
userxattr mounts both the "user.overlay.whiteout*" and the
"trusted.overlay.whiteout*" xattrs will need to be created.
Signed-off-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Diffstat (limited to 'fs/overlayfs/super.c')
| -rw-r--r-- | fs/overlayfs/super.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 0a42a25656fa..1a95ee237fa9 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -585,7 +585,7 @@ static int ovl_check_rename_whiteout(struct ovl_fs *ofs) if (IS_ERR(whiteout)) goto cleanup_temp; - err = ovl_is_whiteout(whiteout); + err = ovl_upper_is_whiteout(ofs, whiteout); /* Best effort cleanup of whiteout and temp file */ if (err) |