From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: [PATCH] raid5-cache: add journal hot add/remove support Date: Wed, 16 Dec 2015 14:42:27 +1100 Message-ID: <87y4cv9hzw.fsf@notabene.neil.brown.name> References: <48dfb85817d51f68d8da85368711ed14f945caa4.1450159900.git.shli@fb.com> <87r3inb3eh.fsf@notabene.neil.brown.name> <20151216013310.GA741432@devbig084.prn1.facebook.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Return-path: In-Reply-To: <20151216013310.GA741432@devbig084.prn1.facebook.com> Sender: linux-raid-owner@vger.kernel.org To: Shaohua Li Cc: linux-raid@vger.kernel.org, Kernel-team@fb.com, songliubraving@fb.com, hch@infradead.org List-Id: linux-raid.ids --=-=-= Content-Type: text/plain 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 --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJWcN2jAAoJEDnsnt1WYoG58o4P/j6zahTvcnMCHnb/P2Upo8os 7aRA+E9GbRk+3JLgmhtD+pC60S7DXZoU7htTPKuW5c5mwxSNcHwMg6NVwu78/50o wcC0tQSbxTst6S6Zxh93xvU1fEZkmG7k8mlqoMSdQMw0j2ucarrkoB9MDnWgGPM2 Vng8K2cNs4XDQIeGOYV0POXLr5yk++FeI9uIYMyZqNukWGiPXMp2OxpYsmaMsuEZ w8rD+QYXokPc3qUleUhFTPOBdn9NGoVwQsWTzQYdIGKE9ZgODLIivOZB7eS6n0vx +J7DOGEwS14VjhwMtyLjBYe7iEr8EXEHMZXAv+evQRRecxFz4zTAaiQthCaAQeZt EGQJRsgNCfsZwAuMwPqIvY1Av0WCSqg9oec9VJltdhn69e9dU2gZkREJ1JyMP7vG qWSHKqE98MW0zHWHUve2DXlLVUDvIhJELxXReVP+acOnWaoFRkWJIAzGO5Ic3aVu dUnduo4Z99WzUa/EYtGPqOiLbWAo3Ch7oTk1jAv5AYh0RVkZ0qt/8Er32y74KkSU x87gHKkLGtDrEgG3+1F9/8L36XUNGofeg+t0PZ15xULk6ChbfWSny6GrSKn3FqSI c3MjEROmYy/76Avk/YUutMVTY5l8yG99NPi+x7HiCojglXMnOptMnme0q8cn6K32 Cncu3Y9K9Rs+wq/m/tRs =VwOE -----END PGP SIGNATURE----- --=-=-=--