From 83206d66b65118d995c38746f21edc2bb8564b49 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 26 Jul 2011 11:19:49 +1000 Subject: md/raid5: Remove use of sh->lock in sync_request This is the start of a series of patches to remove sh->lock. sync_request takes sh->lock before setting STRIPE_SYNCING to ensure there is no race with testing it in handle_stripe[56]. Instead, use a new flag STRIPE_SYNC_REQUESTED and test it early in handle_stripe[56] (after getting the same lock) and perform the same set/clear operations if it was set. Signed-off-by: NeilBrown Reviewed-by: Namhyung Kim --- drivers/md/raid5.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'drivers/md/raid5.c') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 71480646a459..f2f2ab329690 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3022,6 +3022,10 @@ static void handle_stripe5(struct stripe_head *sh) sh->reconstruct_state); spin_lock(&sh->lock); + if (test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) { + set_bit(STRIPE_SYNCING, &sh->state); + clear_bit(STRIPE_INSYNC, &sh->state); + } clear_bit(STRIPE_HANDLE, &sh->state); clear_bit(STRIPE_DELAYED, &sh->state); @@ -3313,6 +3317,10 @@ static void handle_stripe6(struct stripe_head *sh) memset(&s, 0, sizeof(s)); spin_lock(&sh->lock); + if (test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) { + set_bit(STRIPE_SYNCING, &sh->state); + clear_bit(STRIPE_INSYNC, &sh->state); + } clear_bit(STRIPE_HANDLE, &sh->state); clear_bit(STRIPE_DELAYED, &sh->state); @@ -4373,10 +4381,7 @@ static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *ski bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded); - spin_lock(&sh->lock); - set_bit(STRIPE_SYNCING, &sh->state); - clear_bit(STRIPE_INSYNC, &sh->state); - spin_unlock(&sh->lock); + set_bit(STRIPE_SYNC_REQUESTED, &sh->state); handle_stripe(sh); release_stripe(sh); -- cgit v1.2.3-55-g7522