Messages in this thread Patch in this message |  | | Date | Mon, 1 Dec 2025 22:16:49 +0000 | | Subject | Re: [PATCH 2/2] debugfs: Remove broken no-mount mode | | From | Aaron Thompson <> |
| |
On 12/1/25 09:15, Mark Brown wrote: > On Thu, Nov 20, 2025 at 10:26:33AM +0000, Aaron Thompson wrote: > >> debugfs access modes were added in Linux 5.10 (Dec 2020) [1], but the >> no-mount mode has behaved effectively the same as the off mode since >> Linux 5.12 (Apr 2021) [2]. The only difference is the specific error >> code returned by the debugfs_create_* functions, which is -ENOENT in >> no-mount mode and -EPERM in off mode. > > I'm seeing regressions in -next in a lot of testing stuff which bisect > to this patch. I've got a test that looks at the deferred probe list to > see if it's empty, and the mm split_huge_page_test which uses a debugfs > file called split_huge_pages. Neither of these mount debugfs for > themselves, they just assume it'll be there - it looks like that's not > happening any more but I didn't investigate properly. > > I don't immediately see what's getting confused, DEBUG_FS_ALLOW_ALL is > the default and not overridden by anything in any defconfig so > debugfs_enabled still ought to be being set, but I didn't actually try > to debug this yet. > > Sample bisect: > > git bisect start > # status: waiting for both good and bad commits > ... > # bad: [f278809475f6835b56de78b28dc2cc0c7e2c20a4] debugfs: Remove broken no-mount mode > git bisect bad f278809475f6835b56de78b28dc2cc0c7e2c20a4 > # first bad commit: [f278809475f6835b56de78b28dc2cc0c7e2c20a4] debugfs: Remove broken no-mount mode
I am terribly sorry, this was a sloppy mistake on my part. The IS_ENABLED() check is missing the CONFIG_ prefix. The fix patch is attached.
Greg, should I send a v2 of the patch series, or a separate patch with just the fix? Or something else? Again, sorry for the trouble.
-- Aaron commit 92dcc0b68643955317fa4174442a6376df5a8c97 Author: Aaron Thompson <dev@aaront.org> Date: Mon Dec 1 22:15:24 2025 +0000
debugfs: Fix IS_ENABLED check
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 930d66911fcd..4b263c328ed2 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -35,7 +35,7 @@ static struct vfsmount *debugfs_mount; static int debugfs_mount_count; static bool debugfs_registered; -static bool debugfs_enabled __ro_after_init = IS_ENABLED(DEBUG_FS_ALLOW_ALL); +static bool debugfs_enabled __ro_after_init = IS_ENABLED(CONFIG_DEBUG_FS_ALLOW_ALL); /* * Don't allow access attributes to be changed whilst the kernel is locked down |  |