From: Shijie Luo <luoshijie1@huawei.com>
To: Jan Kara <jack@suse.cz>, Al Viro <viro@ZenIV.linux.org.uk>
Cc: <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH] fs: fix a hungtask problem when freeze/unfreeze fs
Date: Thu, 21 Jan 2021 10:00:19 +0800 [thread overview]
Message-ID: <15fad91c-66a9-8be2-36fa-5fa2bbbcb7f5@huawei.com> (raw)
In-Reply-To: <20210105134600.24022-1-jack@suse.cz>
friendly ping...
On 2021/1/5 21:46, Jan Kara wrote:
> We found the following deadlock when running xfstests generic/390 with ext4
> filesystem, and simutaneously offlining/onlining the disk we tested. It will
> cause a deadlock whose call trace is like this:
>
> fsstress D 0 11672 11625 0x00000080
> Call Trace:
> ? __schedule+0x2fc/0x930
> ? filename_parentat+0x10b/0x1a0
> schedule+0x28/0x70
> rwsem_down_read_failed+0x102/0x1c0
> ? __percpu_down_read+0x93/0xb0
> __percpu_down_read+0x93/0xb0
> __sb_start_write+0x5f/0x70
> mnt_want_write+0x20/0x50
> do_renameat2+0x1f3/0x550
> __x64_sys_rename+0x1c/0x20
> do_syscall_64+0x5b/0x1b0
> entry_SYSCALL_64_after_hwframe+0x65/0xca
>
> The root cause is that when ext4 hits IO error due to disk being
> offline, it will switch itself into read-only state. When it is frozen
> at that moment, following thaw_super() call will not unlock percpu
> freeze semaphores (as the fs is read-only) causing the deadlock.
>
>
> };
prev parent reply other threads:[~2021-01-21 4:59 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-05 13:46 [PATCH] fs: fix a hungtask problem when freeze/unfreeze fs Jan Kara
2021-01-21 2:00 ` Shijie Luo [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=15fad91c-66a9-8be2-36fa-5fa2bbbcb7f5@huawei.com \
--to=luoshijie1@huawei.com \
--cc=jack@suse.cz \
--cc=linux-fsdevel@vger.kernel.org \
--cc=viro@ZenIV.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.