Messages in this thread | | | Subject | Re: [PATCH] md: fix deadlock causing by sysfs_notify | From | Junxiao Bi <> | Date | Tue, 14 Jul 2020 09:29:41 -0700 |
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On 7/14/20 9:18 AM, Song Liu wrote:
> On Mon, Jul 13, 2020 at 11:41 PM Junxiao Bi <junxiao.bi@oracle.com> wrote: >> On 7/13/20 11:17 PM, Song Liu wrote: >> >>> On Thu, Jul 9, 2020 at 4:36 PM Junxiao Bi <junxiao.bi@oracle.com> wrote: >>>> The following deadlock was captured. The first process is holding 'kernfs_mutex' >>>> and hung by io. The io was staging in 'r1conf.pending_bio_list' of raid1 device, >>>> this pending bio list would be flushed by second process 'md127_raid1', but >>>> it was hung by 'kernfs_mutex'. Using sysfs_notify_dirent_safe() to replace >>>> sysfs_notify() can fix it. There were other sysfs_notify() invoked from io >>>> path, removed all of them. >>>> >>> [...] >>>> Cc: stable@vger.kernel.org >>>> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> >>> Thanks for the patch. It looks good in general. One question though, do we >>> need the same change the following line in md.c:level_store()? >>> >>> sysfs_notify(&mddev->kobj, NULL, "level"); >> Thanks for the review. This one is not in io path, looks it's safe. I >> can change it if you want to align it with others. > This one is the only leftover. Let's also change it.
Sure, i will send a v2.
Thanks,
Junxiao.
> > Thanks, > Song
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