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From: NeilBrown <neilb@suse.de>
To: linux-raid@vger.kernel.org
Subject: [md PATCH 02/23] md/raid10: remove unnecessary smp_mb() from end_sync_write
Date: Wed, 14 Mar 2012 15:40:39 +1100	[thread overview]
Message-ID: <20120314044039.7978.67694.stgit@notabene.brown> (raw)
In-Reply-To: <20120314043555.7978.75486.stgit@notabene.brown>

Recent commit 4ca40c2ce099e4f1ce3 (md/raid10: Allow replacement device ...)
added an smp_mb in end_sync_write.
This was to close a possible race with raid10_remove_disk.
However there is no such race as it is never attempted to remove a
disk while resync (or recovery) is happening.
so the smp_mb is just noise.

Signed-off-by: NeilBrown <neilb@suse.de>
---

 drivers/md/raid10.c |    4 +---
 1 files changed, 1 insertions(+), 3 deletions(-)

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 58c44d6..1a19c96 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1682,10 +1682,8 @@ static void end_sync_write(struct bio *bio, int error)
 	d = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
 	if (repl)
 		rdev = conf->mirrors[d].replacement;
-	if (!rdev) {
-		smp_mb();
+	else
 		rdev = conf->mirrors[d].rdev;
-	}
 
 	if (!uptodate) {
 		if (repl)



  parent reply	other threads:[~2012-03-14  4:40 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-14  4:40 [md PATCH 00/23] md patches heading for 3.4 NeilBrown
2012-03-14  4:40 ` [md PATCH 06/23] md: allow last device to be forcibly removed from RAID1/RAID10 NeilBrown
2012-03-14  4:40 ` [md PATCH 03/23] md/raid5: removed unused 'added_devices' variable NeilBrown
2012-03-14  4:40 ` [md PATCH 01/23] md/raid5: make sure reshape_position is cleared on error path NeilBrown
2012-03-14  4:40 ` [md PATCH 05/23] md/raid5: use atomic_dec_return() instead of atomic_dec() and atomic_read() NeilBrown
2012-03-14  4:40 ` NeilBrown [this message]
2012-03-14  4:40 ` [md PATCH 04/23] md: Use existed macros instead of numbers NeilBrown
2012-03-14  4:40 ` [md PATCH 09/23] md/bitmap: ensure to load bitmap when creating via sysfs NeilBrown
2012-03-14  4:40 ` [md PATCH 12/23] md: add proper merge_bvec handling to RAID0 and Linear NeilBrown
2012-03-14  4:40 ` [md PATCH 14/23] md/raid1: handle merge_bvec_fn in member devices NeilBrown
2012-03-14  4:40 ` [md PATCH 08/23] md: don't set md arrays to readonly on shutdown NeilBrown
2012-04-18 15:37   ` Alexander Lyakas
2012-04-18 17:44     ` Paweł Brodacki
2012-04-18 20:53       ` Alexander Lyakas
2012-04-18 22:48     ` NeilBrown
2012-04-19  9:11       ` Alexander Lyakas
2012-04-19  9:57         ` NeilBrown
2012-04-20 11:30           ` Paweł Brodacki
2012-04-20 12:01             ` NeilBrown
2012-04-21 15:18               ` Paweł Brodacki
2012-04-21 20:42                 ` NeilBrown
2012-04-30 10:32                   ` Paweł Brodacki
2012-04-20 16:26           ` John Robinson
2012-03-14  4:40 ` [md PATCH 10/23] md/raid1, raid10: avoid deadlock during resync/recovery NeilBrown
2012-03-14  4:40 ` [md PATCH 07/23] md: allow re-add to failed arrays NeilBrown
2012-03-14  4:40 ` [md PATCH 13/23] md/raid10: handle merge_bvec_fn in member devices NeilBrown
2012-03-14  4:40 ` [md PATCH 11/23] md: tidy up rdev_for_each usage NeilBrown
2012-03-14  4:40 ` [md PATCH 19/23] md/bitmap: remove some pointless locking NeilBrown
2012-03-14  4:40 ` [md PATCH 21/23] md/bitmap: discard CHUNK_BLOCK_SHIFT macro NeilBrown
2012-03-14  4:40 ` [md PATCH 17/23] md/bitmap: move printing of bitmap status to bitmap.c NeilBrown
2012-03-14  4:40 ` [md PATCH 18/23] md/bitmap: change a 'goto' to a normal 'if' construct NeilBrown
2012-03-14  4:40 ` [md PATCH 15/23] md/raid10 - support resizing some RAID10 arrays NeilBrown
2012-03-14  6:17   ` keld
2012-03-14  6:27     ` NeilBrown
2012-03-14  7:51       ` David Brown
2012-03-14  8:32         ` NeilBrown
2012-03-14 10:20           ` David Brown
2012-03-14 12:37             ` keld
2012-03-14  4:40 ` [md PATCH 22/23] md: fix clearing of the 'changed' flags for the bad blocks list NeilBrown
2012-03-14  4:40 ` [md PATCH 16/23] md/bitmap: remove some unused noise from bitmap.h NeilBrown
2012-03-14  4:40 ` [md PATCH 20/23] md/bitmap: remove unnecessary indirection when allocating NeilBrown
2012-03-14  4:40 ` [md PATCH 23/23] md: Add judgement bb->unacked_exist in function md_ack_all_badblocks() NeilBrown

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