From: NeilBrown <neilb@suse.de>
To: Shaohua Li <shli@fb.com>
Cc: linux-raid@vger.kernel.org, Kernel-team@fb.com,
songliubraving@fb.com, hch@infradead.org
Subject: Re: [PATCH] raid5-cache: add journal hot add/remove support
Date: Wed, 16 Dec 2015 14:42:27 +1100 [thread overview]
Message-ID: <87y4cv9hzw.fsf@notabene.neil.brown.name> (raw)
In-Reply-To: <20151216013310.GA741432@devbig084.prn1.facebook.com>
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On Wed, Dec 16 2015, Shaohua Li wrote:
>> And I'm a bit uncertain about setting rdev->raid_disk to
>> mddev->raid_disks.
>> I thought we decided that "Journal" devices had a different namespace
>> for raid_disk than data disks, so ->raid_disk of 0 was appropriate?
>> Setting the journal raid_disk to mddev->raid_disks might cause problems
>> when we ultimately support reshaping an array with a journal.
>
> 0 will introduce confusion in sysfs entry, eg, which disk should
> xxx/md/rd0 point to? Create a special sys file? This appears the only
> reason we don't use 0.
sysfs_link_rdev already avoids the "rd%d" link of Replacement devices.
Change it and sysfs_unlink_rdev to ignore the Journal device too.
Thanks,
NeilBrown
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prev parent reply other threads:[~2015-12-16 3:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-15 6:22 [PATCH] raid5-cache: add journal hot add/remove support Shaohua Li
2015-12-16 1:14 ` NeilBrown
2015-12-16 1:33 ` Shaohua Li
2015-12-16 3:42 ` NeilBrown [this message]
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