Re: [PATCH 5.10 5/5] kernfs: dont call d_splice_alias() under kernfs node lock

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected.
No action required from the submitter.

The upstream commit SHA1 provided is correct: df6192f47d2311cf40cd4321cc59863a5853b665

WARNING: Author mismatch between patch and upstream commit:
Backport author: Qingfang Deng<dqfext@gmail.com>
Commit author: Ian Kent<raven@themaw.net>

Status in newer kernel trees:
6.14.y | Present (exact SHA1)
6.12.y | Present (exact SHA1)
6.6.y | Present (exact SHA1)
6.1.y | Present (exact SHA1)
5.15.y | Present (exact SHA1)

Note: The patch differs from the upstream commit:
---
1:  df6192f47d231 ! 1:  fde730faa2db3 kernfs: dont call d_splice_alias() under kernfs node lock
    @@ Metadata
      ## Commit message ##
         kernfs: dont call d_splice_alias() under kernfs node lock
     
    +    Commit df6192f47d2311cf40cd4321cc59863a5853b665 upstream.
    +
         The call to d_splice_alias() in kernfs_iop_lookup() doesn't depend on
         any kernfs node so there's no reason to hold the kernfs node lock when
         calling it.
    @@ fs/kernfs/dir.c: static struct dentry *kernfs_iop_lookup(struct inode *dir,
     +	return d_splice_alias(inode, dentry);
      }
      
    - static int kernfs_iop_mkdir(struct user_namespace *mnt_userns,
    + static int kernfs_iop_mkdir(struct inode *dir, struct dentry *dentry,
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.15.y       |  Success    |  Success   |