Merge branch 'overlayfs-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs fixes from Miklos Szeredi:
"This fixes minor issues with the multi-layer update in v4.0"
* 'overlayfs-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: upper fs should not be R/O
ovl: check lowerdir amount for non-upper mount
ovl: print error message for invalid mount options
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index b90952f..5f0d199 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -529,8 +529,7 @@
{
struct ovl_fs *ufs = sb->s_fs_info;
- if (!(*flags & MS_RDONLY) &&
- (!ufs->upper_mnt || (ufs->upper_mnt->mnt_sb->s_flags & MS_RDONLY)))
+ if (!(*flags & MS_RDONLY) && !ufs->upper_mnt)
return -EROFS;
return 0;
@@ -615,9 +614,19 @@
break;
default:
+ pr_err("overlayfs: unrecognized mount option \"%s\" or missing value\n", p);
return -EINVAL;
}
}
+
+ /* Workdir is useless in non-upper mount */
+ if (!config->upperdir && config->workdir) {
+ pr_info("overlayfs: option \"workdir=%s\" is useless in a non-upper mount, ignore\n",
+ config->workdir);
+ kfree(config->workdir);
+ config->workdir = NULL;
+ }
+
return 0;
}
@@ -837,7 +846,6 @@
sb->s_stack_depth = 0;
if (ufs->config.upperdir) {
- /* FIXME: workdir is not needed for a R/O mount */
if (!ufs->config.workdir) {
pr_err("overlayfs: missing 'workdir'\n");
goto out_free_config;
@@ -847,6 +855,13 @@
if (err)
goto out_free_config;
+ /* Upper fs should not be r/o */
+ if (upperpath.mnt->mnt_sb->s_flags & MS_RDONLY) {
+ pr_err("overlayfs: upper fs is r/o, try multi-lower layers mount\n");
+ err = -EINVAL;
+ goto out_put_upperpath;
+ }
+
err = ovl_mount_dir(ufs->config.workdir, &workpath);
if (err)
goto out_put_upperpath;
@@ -869,8 +884,14 @@
err = -EINVAL;
stacklen = ovl_split_lowerdirs(lowertmp);
- if (stacklen > OVL_MAX_STACK)
+ if (stacklen > OVL_MAX_STACK) {
+ pr_err("overlayfs: too many lower directries, limit is %d\n",
+ OVL_MAX_STACK);
goto out_free_lowertmp;
+ } else if (!ufs->config.upperdir && stacklen == 1) {
+ pr_err("overlayfs: at least 2 lowerdir are needed while upperdir nonexistent\n");
+ goto out_free_lowertmp;
+ }
stack = kcalloc(stacklen, sizeof(struct path), GFP_KERNEL);
if (!stack)
@@ -932,8 +953,8 @@
ufs->numlower++;
}
- /* If the upper fs is r/o or nonexistent, we mark overlayfs r/o too */
- if (!ufs->upper_mnt || (ufs->upper_mnt->mnt_sb->s_flags & MS_RDONLY))
+ /* If the upper fs is nonexistent, we mark overlayfs r/o too */
+ if (!ufs->upper_mnt)
sb->s_flags |= MS_RDONLY;
sb->s_d_op = &ovl_dentry_operations;
