Re: [PATCH 0/2] ntfs3: fix deadlocks in ntfs_readdir caused by ni_lock held across dir_emit

Friendly ping.

On 7/1/2026 9:30 AM, Yun Zhou wrote:
> Commit d62cf685d12e ("fs/ntfs3: hold ni_lock across readdir metadata
> walk") extended ni_lock to cover the entire directory walk in
> ntfs_readdir(), including dir_emit() calls that copy data to userspace.
> This introduced multiple deadlocks reported by syzkaller:
> 
> 1. Recursive ni_lock: ntfs_dir_emit() -> ntfs_iget5() -> mi_read()
>     tries to acquire ni_lock on a child inode with the same lock class
>     while the parent's ni_lock is already held.
> 
> 2. Lock-order inversions: dir_emit() may trigger page faults that need
>     mmap_lock or mapping->invalidate_lock, conflicting with paths that
>     acquire those locks before ni_lock (ntfs_fallocate, mmap).
> 
> This series fixes both issues:
> - Patch 1 removes the ntfs_iget5() call that caused recursive locking.
> - Patch 2 releases ni_lock before calling dir_emit(), using the XFS
>    approach of reading data into stable buffers under the lock, then
>    emitting to userspace after releasing it.
> 
> Yun Zhou (2):
>    ntfs3: remove ntfs_iget5 call in ntfs_dir_emit to fix recursive
>      deadlock
>    ntfs3: release ni_lock before dir_emit in ntfs_readdir to fix
>      deadlocks
> 
>   fs/ntfs3/dir.c | 38 ++++++++++++++++++++------------------
>   1 file changed, 20 insertions(+), 18 deletions(-)
>