Re: [PATCH 1/7] VFS/xfs/ntfs: drop parent lock across d_alloc_parallel() in d_add_ci()

[Hyunchul Lee]

On Tue, Sep 29, 2026 at 01:36:01PM +1000, NeilBrown wrote:
> From: NeilBrown <neil@xxxxxxxxxx>
> 
> A proposed change will invert the lock ordering between
> d_alloc_parallel() and inode_lock() on the parent.
> When that happens it will not be safe to call d_alloc_parallel() while
> holding the parent lock - even shared.
> 
> We don't need to keep the parent lock held when d_add_ci() is run - the
> VFS doesn't need it as dentry is exclusively held due to
> DCACHE_PAR_LOOKUP and the filesystem has finished its work.
> 
> So drop and reclaim the lock (shared or exclusive as determined by
> LOOKUP_SHARED) to avoid future deadlock.
> 
> Signed-off-by: NeilBrown <neil@xxxxxxxxxx>

For the NTFS part,

Looks good to me.

Reviewed-by: Hyunchul Lee <hyc.lee@xxxxxxxxx>

-- 
Thanks,
Hyunchul