btrfs: add "0x" prefix for unsupported optional features

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@vger.kernel.org # 4.14+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 8cbed2f..9ab2792 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3370,7 +3370,7 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
                ~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 *sb, struct btrfs_fs_devices *fs_device
                ~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;