Re: [PATCH RESEND v6 6/9] xfs: Implement ->notify_failure() for XFS

On Thu, Aug 5, 2021 at 5:50 PM Jane Chu [off-list ref] wrote:

On 7/30/2021 3:01 AM, Shiyang Ruan wrote:

quoted

+     mapping = VFS_I(ip)->i_mapping;
+     if (IS_ENABLED(CONFIG_MEMORY_FAILURE)) {
+             for (i = 0; i < rec->rm_blockcount; i++) {
+                     error = mf_dax_kill_procs(mapping, rec->rm_offset + i,
+                                               *flags);
+                     if (error)
+                             break;
+             }
+     }

If a poison is injected to a PMD dax page, after consuming the poison,
how many SIGBUS signals are expected to be sent to the process?

I think it should only get one. I.e. just like the the generic code
does one shootdown per mapped page regardless of whether that page is
4K, 2M, or 1G. Once the application is notified it should be able to
query the filesystem to determine the full extent of the damage to
files.