The fix in question is:

commit e7a2fa70c3b0d8c8cee2b484038bb5623c7c1ea9
Author: Tom Caputi <[email protected]>
Date:   Tue Aug 27 12:55:51 2019 -0400

    Fix deadlock in 'zfs rollback'
    
    Currently, the 'zfs rollback' code can end up deadlocked due to
    the way the kernel handles unreferenced inodes on a suspended fs.
    Essentially, the zfs_resume_fs() code path may cause zfs to spawn
    new threads as it reinstantiates the suspended fs's zil. When a
    new thread is spawned, the kernel may attempt to free memory for
    that thread by freeing some unreferenced inodes. If it happens to
    select inodes that are a a part of the suspended fs a deadlock
    will occur because freeing inodes requires holding the fs's
    z_teardown_inactive_lock which is still held from the suspend.
    
    This patch corrects this issue by adding an additional reference
    to all inodes that are still present when a suspend is initiated.
    This prevents them from being freed by the kernel for any reason.
    
    Reviewed-by: Alek Pinchuk <[email protected]>
    Reviewed-by: Brian Behlendorf <[email protected]>
    Signed-off-by: Tom Caputi <[email protected]>
    Closes #9203


** Changed in: zfs-linux (Ubuntu)
     Assignee: (unassigned) => Colin Ian King (colin-king)

** Changed in: zfs-linux (Ubuntu)
   Importance: Undecided => High

** Changed in: zfs-linux (Ubuntu)
       Status: New => In Progress

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1847832

Title:
  Backport ZoL pull request 9203 into the official packages.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/1847832/+subscriptions

-- 
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to