From: Neil Brown <neilb@suse.de>
To: Krzysztof Wojcik <krzysztof.wojcik@intel.com>
Cc: linux-raid@vger.kernel.org, wojciech.neubauer@intel.com,
adam.kwolek@intel.com, dan.j.williams@intel.com,
ed.ciechanowski@intel.com
Subject: Re: [PATCH 07/13] Grow: add missing raid4 geometries to geo_map()
Date: Tue, 23 Nov 2010 15:16:32 +1100 [thread overview]
Message-ID: <20101123151632.1ee99cc5@notabene.brown> (raw)
In-Reply-To: <20101118092217.29508.33761.stgit@gklab-170-111.igk.intel.com>
On Thu, 18 Nov 2010 10:22:17 +0100
Krzysztof Wojcik <krzysztof.wojcik@intel.com> wrote:
> From: Dan Williams <dan.j.williams@intel.com>
>
> They are equivalent to their raid5 versions and let the reshape code
> optionally use either.
>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
> restripe.c | 2 ++
> 1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/restripe.c b/restripe.c
> index 3074693..c2fbe5b 100644
> --- a/restripe.c
> +++ b/restripe.c
> @@ -46,6 +46,7 @@ static int geo_map(int block, unsigned long long stripe, int raid_disks,
> switch(level*100 + layout) {
> case 000:
> case 400:
> + case 400 + ALGORITHM_PARITY_N:
> case 500 + ALGORITHM_PARITY_N:
> /* raid 4 isn't messed around by parity blocks */
> if (block == -1)
> @@ -75,6 +76,7 @@ static int geo_map(int block, unsigned long long stripe, int raid_disks,
> if (block == -1) return pd;
> return (pd + 1 + block) % raid_disks;
>
> + case 400 + ALGORITHM_PARITY_0:
> case 500 + ALGORITHM_PARITY_0:
> return block + 1;
>
I'm not sure about this.
In the kernel, raid4 ignores the 'layout'. So it seems safest to do the same
in mdadm, and always use a level of '5' when we want PARITY_0.
Why is this needed exactly?
Thanks,
NeilBrown
next prev parent reply other threads:[~2010-11-23 4:16 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-18 9:21 [PATCH 00/13] Series short description Krzysztof Wojcik
2010-11-18 9:21 ` [PATCH 01/13] Provide a mdstat_ent to subarray helper Krzysztof Wojcik
2010-11-18 9:21 ` [PATCH 02/13] block monitor: freeze spare assignment for external arrays Krzysztof Wojcik
2010-11-23 4:03 ` Neil Brown
2010-11-18 9:21 ` [PATCH 03/13] Manage: allow manual control of external raid0 readonly flag Krzysztof Wojcik
2010-11-23 4:08 ` Neil Brown
2010-11-18 9:21 ` [PATCH 04/13] Grow: mark some functions static Krzysztof Wojcik
2010-11-18 9:22 ` [PATCH 05/13] Assemble: fix assembly in the delta_disks > max_degraded case Krzysztof Wojcik
2010-11-18 9:22 ` [PATCH 06/13] Grow: fix check for raid6 layout normalization Krzysztof Wojcik
2010-11-18 9:22 ` [PATCH 07/13] Grow: add missing raid4 geometries to geo_map() Krzysztof Wojcik
2010-11-23 4:16 ` Neil Brown [this message]
2010-11-18 9:22 ` [PATCH 08/13] fix a get_linux_version() comparison typo Krzysztof Wojcik
2010-11-18 9:22 ` [PATCH 09/13] Create: cleanup/unify default geometry handling Krzysztof Wojcik
2010-11-18 9:22 ` [PATCH 10/13] Initialize st->devnum and st->container_dev in super_by_fd Krzysztof Wojcik
2010-11-18 9:22 ` [PATCH 11/13] Document the external reshape implementation Krzysztof Wojcik
2010-11-23 4:52 ` Neil Brown
2010-11-18 9:22 ` [PATCH 12/13] External reshape (step 1): container reshape and ->reshape_super() Krzysztof Wojcik
2010-11-23 5:22 ` Neil Brown
2010-11-18 9:23 ` [PATCH 13/13] External reshape (step 2): Freeze container Krzysztof Wojcik
2010-11-23 6:11 ` Neil Brown
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