[PATCH] btrfs: add "0x" prefix for unsupported optional features

[PATCH] btrfs: add "0x" prefix for unsupported optional features

[Qu Wenruo]

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

  cannot mount because of unsupported optional features (4000)

Just add the prefix before any complains.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/disk-io.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 03e17fccc88e..fe309db9f5ff 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3612,7 +3612,7 @@ 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;
@@ -3650,7 +3650,7 @@ 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;
-- 
2.36.0

Re: [PATCH] btrfs: add "0x" prefix for unsupported optional features

[Nikolay Borisov]

On 10.05.22 г. 10:10 ч., Qu Wenruo wrote:
> The following error message lack the "0x" obviously:
> 
>    cannot mount because of unsupported optional features (4000)
> 
> Just add the prefix before any complains.
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

Though it doesn't make the output any more readable for humans :)

Re: [PATCH] btrfs: add "0x" prefix for unsupported optional features

[David Sterba]

On Tue, May 10, 2022 at 11:06:19AM +0300, Nikolay Borisov wrote:
> 
> 
> On 10.05.22 г. 10:10 ч., Qu Wenruo wrote:
> > The following error message lack the "0x" obviously:
> > 
> >    cannot mount because of unsupported optional features (4000)
> > 
> > Just add the prefix before any complains.
> > 
> > Signed-off-by: Qu Wenruo <wqu@suse.com>
> 
> Reviewed-by: Nikolay Borisov <nborisov@suse.com>
> 
> Though it doesn't make the output any more readable for humans :)

We can't do much better here, if the feature would be known and have a
textual description it would be caught, so the raw value is at least
something that can be matched in the newer versions.

Re: [PATCH] btrfs: add "0x" prefix for unsupported optional features

[David Sterba]

On Tue, May 10, 2022 at 03:10:18PM +0800, Qu Wenruo wrote:
> The following error message lack the "0x" obviously:
> 
>   cannot mount because of unsupported optional features (4000)
> 
> Just add the prefix before any complains.
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>

Added to misc-next and tagged for stable as older kernels are more
likely to encounter unknown features.