linux.git/fs/overlayfs, branch v4.12

ovl: don't set origin on broken lower hardlink

2017-06-28T11:41:22+00:00

When copying up a file that has multiple hard links we need to break any
association with the origin file.  This makes copy-up be essentially an
atomic replace.

The new file has nothing to do with the old one (except having the same
data and metadata initially), so don't set the overlay.origin attribute.

We can relax this in the future when we are able to index upper object by
origin.

Signed-off-by: Miklos Szeredi 
Fixes: 3a1e819b4e80 ("ovl: store file handle of lower inode on copy up")

ovl: copy-up: don't unlock between lookup and link

2017-06-28T11:41:22+00:00

Nothing prevents mischief on upper layer while we are busy copying up the
data.

Move the lookup right before the looked up dentry is actually used.

Signed-off-by: Miklos Szeredi 
Fixes: 01ad3eb8a073 ("ovl: concurrent copy up of regular files")
Cc:  # v4.11

ovl: filter trusted xattr for non-admin

2017-05-29T13:15:27+00:00

Filesystems filter out extended attributes in the "trusted." domain for
unprivlieged callers.

Overlay calls underlying filesystem's method with elevated privs, so need
to do the filtering in overlayfs too.

Signed-off-by: Miklos Szeredi

ovl: mark upper merge dir with type origin entries "impure"

2017-05-29T09:48:00+00:00

An upper dir is marked "impure" to let ovl_iterate() know that this
directory may contain non pure upper entries whose d_ino may need to be
read from the origin inode.

We already mark a non-merge dir "impure" when moving a non-pure child
entry inside it, to let ovl_iterate() know not to iterate the non-merge
dir directly.

Mark also a merge dir "impure" when moving a non-pure child entry inside
it and when copying up a child entry inside it.

This can be used to optimize ovl_iterate() to perform a "pure merge" of
upper and lower directories, merging the content of the directories,
without having to read d_ino from origin inodes.

Signed-off-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

ovl: mark upper dir with type origin entries "impure"

2017-05-19T07:33:49+00:00

When moving a merge dir or non-dir with copy up origin into a non-merge
upper dir (a.k.a pure upper dir), we are marking the target parent dir
"impure". ovl_iterate() iterates pure upper dirs directly, because there is
no need to filter out whiteouts and merge dir content with lower dir. But
for the case of an "impure" upper dir, ovl_iterate() will not be able to
iterate the real upper dir directly, because it will need to lookup the
origin inode and use it to fill d_ino.

Signed-off-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

ovl: remove unused arg from ovl_lookup_temp()

2017-05-19T07:33:49+00:00

Signed-off-by: Miklos Szeredi

ovl: handle rename when upper doesn't support xattr

2017-05-19T07:33:49+00:00

On failure to set opaque/redirect xattr on rename, skip setting xattr and
return -EXDEV.

On failure to set opaque xattr when creating a new directory, -EIO is
returned instead of -EOPNOTSUPP.

Any failure to set those xattr will be recorded in super block and
then setting any xattr on upper won't be attempted again.

Signed-off-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

ovl: don't fail copy-up if upper doesn't support xattr

2017-05-18T14:11:24+00:00

Signed-off-by: Miklos Szeredi

ovl: check on mount time if upper fs supports setting xattr

2017-05-18T14:11:24+00:00

xattr are needed by overlayfs for setting opaque dir, redirect dir
and copy up origin.

Check at mount time by trying to set the overlay.opaque xattr on the
workdir and if that fails issue a warning message.

Signed-off-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

ovl: fix creds leak in copy up error path

2017-05-18T14:11:24+00:00

Fixes: 42f269b92540 ("ovl: rearrange code in ovl_copy_up_locked()")
Cc:  # v4.11
Signed-off-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi