Re: [PATCH v2] ntfs: fail attrlist updates when the superblock is inactive

[Namjae Jeon]

On Mon, Jul 6, 2026 at 1:01 PM Peiyang He <peiyang_he@xxxxxxxxxxxxxxxx> wrote:
>
> generic_shutdown_super() clears SB_ACTIVE before evicting cached inodes.
> If eviction selects the fake inode for a base inode's unnamed
> $ATTRIBUTE_LIST attribute, ntfs_evict_big_inode() drops the fake inode's
> reference on the base inode while the fake inode is still hashed and marked
> I_FREEING.
>
> That iput can synchronously write back the base inode. The writeback path
> may update mapping pairs and call ntfs_attrlist_update(), which
> unconditionally calls ntfs_attr_iget() for the same $ATTRIBUTE_LIST fake
> inode. VFS then finds the I_FREEING inode and waits for eviction to finish,
> but the current task is still inside that eviction path, causing a
> self-deadlock in find_inode().
>
> Fix this by mirroring the teardown guard used by __ntfs_write_inode():
> once SB_ACTIVE has been cleared, do not try to iget the attribute-list fake inode.
> Return -EIO so teardown aborts the update instead of waiting on the inode it is evicting.
>
> Reported-by: Peiyang He <peiyang_he@xxxxxxxxxxxxxxxx>
> Closes: https://lore.kernel.org/all/AB8D5E603E6EA856+ae5f622a-dd3a-4e38-bdd2-42276ae0e1a8@xxxxxxxxxxxxxxxx/
> Fixes: 495e90fa3348 ("ntfs: update attrib operations")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Peiyang He <peiyang_he@xxxxxxxxxxxxxxxx>
> Assisted-by: Codex:gpt-5.5
> Reviewed-by: Hyunchul Lee <hyc.lee@xxxxxxxxx>
Applied it to #ntfs-next.
Thanks!