diff options
Diffstat (limited to 'fs/overlayfs/super.c')
| -rw-r--r-- | fs/overlayfs/super.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 7621ff176d15..d6b724beb304 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1258,6 +1258,18 @@ static bool ovl_lower_uuid_ok(struct ovl_fs *ofs, const uuid_t *uuid) if (!ofs->config.nfs_export && !ofs->upper_mnt) return true; + /* + * We allow using single lower with null uuid for index and nfs_export + * for example to support those features with single lower squashfs. + * To avoid regressions in setups of overlay with re-formatted lower + * squashfs, do not allow decoding origin with lower null uuid unless + * user opted-in to one of the new features that require following the + * lower inode of non-dir upper. + */ + if (!ofs->config.index && !ofs->config.metacopy && !ofs->config.xino && + uuid_is_null(uuid)) + return false; + for (i = 0; i < ofs->numlowerfs; i++) { /* * We use uuid to associate an overlay lower file handle with a @@ -1344,14 +1356,23 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs, if (err < 0) goto out; + /* + * Check if lower root conflicts with this overlay layers before + * checking if it is in-use as upperdir/workdir of "another" + * mount, because we do not bother to check in ovl_is_inuse() if + * the upperdir/workdir is in fact in-use by our + * upperdir/workdir. + */ err = ovl_setup_trap(sb, stack[i].dentry, &trap, "lowerdir"); if (err) goto out; if (ovl_is_inuse(stack[i].dentry)) { err = ovl_report_in_use(ofs, "lowerdir"); - if (err) + if (err) { + iput(trap); goto out; + } } mnt = clone_private_mount(&stack[i]); |