FAILED: patch "[PATCH] ovl: warn instead of error if d_type is not supported" failed to apply to 4.6-stable tree

From e7c0b5991dd1be7b6f6dc2b54a15a0f47b64b007 Mon Sep 17 00:00:00 2001

The patch below does not apply to the 4.6-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

------------------ original commit in Linus's tree ------------------

From e7c0b5991dd1be7b6f6dc2b54a15a0f47b64b007 Mon Sep 17 00:00:00 2001
From: Vivek Goyal <[email protected]>
Date: Fri, 1 Jul 2016 10:02:44 -0400
Subject: [PATCH] ovl: warn instead of error if d_type is not supported

overlay needs underlying fs to support d_type. Recently I put in a patch in to detect this condition and started failing mount if underlying fs did not support d_type.

But this breaks existing configurations over kernel upgrade. Those who are running docker (partially broken configuration) with xfs not supporting d_type, are surprised that after kernel upgrade docker does not run anymore.

https://github.com/docker/docker/issues/22937#issuecomment-229881315

So instead of erroring out, detect broken configuration and warn about it. This should allow existing docker setups to continue working after kernel upgrade.

Signed-off-by Vivek Goyal <[email protected]>

Signed-off-by Miklos Szeredi <[email protected]>

Fixes 45aebeaf4f67 ("ovl: Ensure upper filesystem supports d_type")

Cc <[email protected]> 4.6

fs/overlayfs/super.c +7 -5

index ce02f46029da..9a7693d5f8ff 100644
@@ -1082,11 +1082,13 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
                        if (err < 0)
                                goto out_put_workdir;
 
-                       if (!err) {
-                               pr_err("overlayfs: upper fs needs to support d_type.\n");
-                               err = -EINVAL;
-                               goto out_put_workdir;
-                       }
+                       /*
+                        * We allowed this configuration and don't want to
+                        * break users over kernel upgrade. So warn instead
+                        * of erroring out.
+                        */
+                       if (!err)
+                               pr_warn("overlayfs: upper fs needs to support d_type.\n");
                }
        }
 

Quoted 5 lines · On Mon, Jul 25, 2016 at 2:18 AM, <[email protected]> wrote:

The patch below does not apply to the 4.6-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

This depends on the following commit:

21765194cecf ("ovl: Do d_type check only if work dir creation was successful")