Re: [linux-lvm] resend patch - bcache may mistakenly write data to another disk when writes error

[Joe Thornber <thornber@redhat.com>]

On Thu, Oct 24, 2019 at 03:06:18AM +0000, Heming Zhao wrote:
> First fail is in bcache_flush, then bcache_invalidate_fd does nothing because the data
> in cache->errored, which not belongs to dirty & clean list. Then the data mistakenly
> move from cache->errored into cache->dirty by "bcache_get => _lookup_or_read_block"
> (because the data holds BF_DIRTY flag).

I just pushed a couple of patches that will hopefully fix this issue for you:

commit 6b0d969b2a85ba69046afa26af4d7bcddddbccd5 (HEAD -> master, origin/master, origin/HEAD, 2019-10-11-bcache-purge)
Author: Joe Thornber <ejt@redhat.com>
Date:   Mon Oct 28 15:01:47 2019 +0000

    [label] Use bcache_abort_fd() to ensure blocks are no longer in the cache.
    
    The return value from bcache_invalidate_fd() was not being checked.
    
    So I've introduced a little function, _invalidate_fd() that always
    calls bcache_abort_fd() if the write fails.

commit 2938b4dcca0a1df661758abfab7f402ea7aab018
Author: Joe Thornber <ejt@redhat.com>
Date:   Mon Oct 28 14:29:47 2019 +0000

    [bcache] add bcache_abort()
    
    This gives us a way to cope with write failures.




Also there are big changes to bcache coming, that remove file descriptors from
the interface completely.  See the branch 2019-09-05-add-io-manager for more info
(bcache has been renamed io_manager).

- Joe