On Fri, Aug 26, 2022 at 10:18:14AM -0700, Dan Williams wrote:
> In the case where a filesystem is polled to take over the memory failure
> and receives -EOPNOTSUPP it indicates that page->index and page->mapping
> are valid for reverse mapping the failure address. Introduce
> FSDAX_INVALID_PGOFF to distinguish when add_to_kill() is being called
> from mf_dax_kill_procs() by a filesytem vs the typical memory_failure()
> path.
>
> Otherwise, vma_pgoff_address() is called with an invalid fsdax_pgoff
> which then trips this failing signature:
>
> kernel BUG at mm/memory-failure.c:319!
> invalid opcode: 0000 [#1] PREEMPT SMP PTI
> CPU: 13 PID: 1262 Comm: dax-pmd Tainted: G OE N 6.0.0-rc2+ #62
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
> RIP: 0010:add_to_kill.cold+0x19d/0x209
> [..]
> Call Trace:
> <TASK>
> collect_procs.part.0+0x2c4/0x460
> memory_failure+0x71b/0xba0
> ? _printk+0x58/0x73
> do_madvise.part.0.cold+0xaf/0xc5
>
> Fixes: c36e20249571 ("mm: introduce mf_dax_kill_procs() for fsdax case")
> Cc: Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Darrick J. Wong <djwong@xxxxxxxxxx>
> Cc: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> Cc: Dave Chinner <david@xxxxxxxxxxxxx>
> Cc: Goldwyn Rodrigues <rgoldwyn@xxxxxxx>
> Cc: Jane Chu <jane.chu@xxxxxxxxxx>
> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
> Cc: Ritesh Harjani <riteshh@xxxxxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Acked-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
