From 83206d66b65118d995c38746f21edc2bb8564b49 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 26 Jul 2011 11:19:49 +1000 Subject: [PATCH] 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 +++++++++---- drivers/md/raid5.h | 33 ++++++++++++++++++--------------- 2 files changed, 27 insertions(+), 19 deletions(-) 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); diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index 3ca77a2613ba..a33001137bf8 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -289,21 +289,24 @@ struct r6_state { /* * Stripe state */ -#define STRIPE_HANDLE 2 -#define STRIPE_SYNCING 3 -#define STRIPE_INSYNC 4 -#define STRIPE_PREREAD_ACTIVE 5 -#define STRIPE_DELAYED 6 -#define STRIPE_DEGRADED 7 -#define STRIPE_BIT_DELAY 8 -#define STRIPE_EXPANDING 9 -#define STRIPE_EXPAND_SOURCE 10 -#define STRIPE_EXPAND_READY 11 -#define STRIPE_IO_STARTED 12 /* do not count towards 'bypass_count' */ -#define STRIPE_FULL_WRITE 13 /* all blocks are set to be overwritten */ -#define STRIPE_BIOFILL_RUN 14 -#define STRIPE_COMPUTE_RUN 15 -#define STRIPE_OPS_REQ_PENDING 16 +enum { + STRIPE_HANDLE, + STRIPE_SYNC_REQUESTED, + STRIPE_SYNCING, + STRIPE_INSYNC, + STRIPE_PREREAD_ACTIVE, + STRIPE_DELAYED, + STRIPE_DEGRADED, + STRIPE_BIT_DELAY, + STRIPE_EXPANDING, + STRIPE_EXPAND_SOURCE, + STRIPE_EXPAND_READY, + STRIPE_IO_STARTED, /* do not count towards 'bypass_count' */ + STRIPE_FULL_WRITE, /* all blocks are set to be overwritten */ + STRIPE_BIOFILL_RUN, + STRIPE_COMPUTE_RUN, + STRIPE_OPS_REQ_PENDING, +}; /* * Operation request flags -- 2.39.5