diff options
| author | Amir Goldstein <amir73il@gmail.com> | 2017-03-22 08:42:21 -0400 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2017-05-05 11:38:57 +0200 |
| commit | 7bcd74b98d7bac3e5149894caaf72de6989af7f0 (patch) | |
| tree | 0b7b0bb5dd7848ad6572b50d64ad81059e2b5fae /fs/overlayfs/super.c | |
| parent | 4a99f3c83dc493c8ea84693d78cd792839c8aa64 (diff) | |
ovl: check if all layers are on the same fs
Some features can only work when all layers are on the same fs. Test this
condition during mount time, so features can check them later.
Add helper ovl_same_sb() to return the common super block in case all
layers are on the same fs.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/super.c')
| -rw-r--r-- | fs/overlayfs/super.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 6faefa54cb5e..9828b7de8999 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -914,11 +914,19 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) ufs->lower_mnt[ufs->numlower] = mnt; ufs->numlower++; + + /* Check if all lower layers are on same sb */ + if (i == 0) + ufs->same_sb = mnt->mnt_sb; + else if (ufs->same_sb != mnt->mnt_sb) + ufs->same_sb = NULL; } /* If the upper fs is nonexistent, we mark overlayfs r/o too */ if (!ufs->upper_mnt) sb->s_flags |= MS_RDONLY; + else if (ufs->upper_mnt->mnt_sb != ufs->same_sb) + ufs->same_sb = NULL; if (remote) sb->s_d_op = &ovl_reval_dentry_operations; |