[PATCH 5.15 039/667] btrfs: add "0x" prefix for unsupported optional features

[Greg Kroah-Hartman]

From: Qu Wenruo <wqu@xxxxxxxx>

commit d5321a0fa8bc49f11bea0b470800962c17d92d8f upstream.

The following error message lack the "0x" obviously:

  cannot mount because of unsupported optional features (4000)

Add the prefix to make it less confusing. This can happen on older
kernels that try to mount a filesystem with newer features so it makes
sense to backport to older trees.

CC: stable@xxxxxxxxxxxxxxx # 4.14+
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 fs/btrfs/disk-io.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3370,7 +3370,7 @@ int __cold open_ctree(struct super_block
 		~BTRFS_FEATURE_INCOMPAT_SUPP;
 	if (features) {
 		btrfs_err(fs_info,
-		    "cannot mount because of unsupported optional features (%llx)",
+		    "cannot mount because of unsupported optional features (0x%llx)",
 		    features);
 		err = -EINVAL;
 		goto fail_alloc;
@@ -3408,7 +3408,7 @@ int __cold open_ctree(struct super_block
 		~BTRFS_FEATURE_COMPAT_RO_SUPP;
 	if (!sb_rdonly(sb) && features) {
 		btrfs_err(fs_info,
-	"cannot mount read-write because of unsupported optional features (%llx)",
+	"cannot mount read-write because of unsupported optional features (0x%llx)",
 		       features);
 		err = -EINVAL;
 		goto fail_alloc;