lkml.org 
[lkml]   [2020]   [Jul]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 4.19 082/131] nvme: fix possible deadlock when I/O is blocked
Hi!

> From: Sagi Grimberg <sagi@grimberg.me>
>
> [ Upstream commit 3b4b19721ec652ad2c4fe51dfbe5124212b5f581 ]
>
> Revert fab7772bfbcf ("nvme-multipath: revalidate nvme_ns_head gendisk
> in nvme_validate_ns")
>
> When adding a new namespace to the head disk (via nvme_mpath_set_live)
> we will see partition scan which triggers I/O on the mpath device node.
> This process will usually be triggered from the scan_work which holds
> the scan_lock. If I/O blocks (if we got ana change currently have only
> available paths but none are accessible) this can deadlock on the head
> disk bd_mutex as both partition scan I/O takes it, and head disk revalidation
> takes it to check for resize (also triggered from scan_work on a different
> path). See trace [1].
>
> The mpath disk revalidation was originally added to detect online disk
> size change, but this is no longer needed since commit cb224c3af4df
> ("nvme: Convert to use set_capacity_revalidate_and_notify") which already
> updates resize info without unnecessarily revalidating the disk (the

Unfortunately, v4.19-stable does not contain cb224c3af4df. According
to changelog, it seems it should be cherry-picked?

Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2020-07-02 23:18    [W:0.504 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site