[LU-8358] Update condition on vvp_vmpage_error to match error code in RPC

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.11.0
• Labels: patch
• Severity: 3
• Assignee: WC Triage
• Reporter: Patrick Farrell (Inactive)

Description

When a Lustre client is evicted (or otherwise suffers fatal RPC interruption), it is supposed to print a warning (ll_dirty_page_discard_warn) for any dirty pages (once per set...) which may have been lost due to the eviction.

This is handled in vvp_vmpage_error, with a condition that checks the return code in the RPC.

Unfortunately, LU-1030 changed the error code set on RPCs in an eviction from -EINTR to -EIO:
http://review.whamcloud.com/#/c/2270/25/lustre/ptlrpc/client.c

But did not update the check in vvp_vmpage_error:

                if ((ioret == -ESHUTDOWN || ioret == -EINTR) &&
                     obj->vob_discard_page_warned == 0) {
                        obj->vob_discard_page_warned = 1;
                        ll_dirty_page_discard_warn(vmpage, ioret);

It's still possible to get -EINTR here for an interrupted RPC (see osc_brw_redo_request), so I think we need to add -EIO to this mix.

Cray noticed this because we were seeing dropped pages after evictions without the message printed. Adding -EIO to this condition resolves this.