md: kill STRIPE_OP_IO flag

From: Dan Williams <dan.j.williams@intel.com>

The R5_Want{Read,Write} flags already gate i/o.  So, this flag is
superfluous and we can unconditionally call ops_run_io().

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Neil Brown <neilb@suse.de>

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 60e61d2..cac9708 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -373,8 +373,6 @@ static unsigned long get_stripe_work(struct stripe_head *sh)
        test_and_ack_op(STRIPE_OP_BIODRAIN, pending);
        test_and_ack_op(STRIPE_OP_POSTXOR, pending);
        test_and_ack_op(STRIPE_OP_CHECK, pending);
-       if (test_and_clear_bit(STRIPE_OP_IO, &sh->ops.pending))
-               ack++;
 
        sh->ops.count -= ack;
        if (unlikely(sh->ops.count < 0)) {
@@ -399,7 +397,6 @@ static void ops_run_io(struct stripe_head *sh)
 
        might_sleep();
 
-       set_bit(STRIPE_IO_STARTED, &sh->state);
        for (i = disks; i--; ) {
                int rw;
                struct bio *bi;
@@ -433,6 +430,8 @@ static void ops_run_io(struct stripe_head *sh)
                                test_bit(STRIPE_EXPAND_READY, &sh->state))
                                md_sync_acct(rdev->bdev, STRIPE_SECTORS);
 
+                       set_bit(STRIPE_IO_STARTED, &sh->state);
+
                        bi->bi_bdev = rdev->bdev;
                        pr_debug("%s: for %llu schedule op %ld on disc %d\n",
                                __func__, (unsigned long long)sh->sector,
@@ -900,9 +899,6 @@ static void raid5_run_ops(struct stripe_head *sh, unsigned long pending)
        if (test_bit(STRIPE_OP_CHECK, &pending))
                ops_run_check(sh);
 
-       if (test_bit(STRIPE_OP_IO, &pending))
-               ops_run_io(sh);
-
        if (overlap_clear)
                for (i = disks; i--; ) {
                        struct r5dev *dev = &sh->dev[i];
@@ -2013,8 +2009,6 @@ static int __handle_issuing_new_read_requests5(struct stripe_head *sh,
                         */
                        set_bit(R5_LOCKED, &dev->flags);
                        set_bit(R5_Wantread, &dev->flags);
-                       if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
-                               sh->ops.count++;
                        s->locked++;
                        pr_debug("Reading block %d (sync=%d)\n", disk_idx,
                                s->syncing);
@@ -2208,9 +2202,6 @@ static void handle_issuing_new_write_requests5(raid5_conf_t *conf,
                                                "%d for r-m-w\n", i);
                                        set_bit(R5_LOCKED, &dev->flags);
                                        set_bit(R5_Wantread, &dev->flags);
-                                       if (!test_and_set_bit(
-                                               STRIPE_OP_IO, &sh->ops.pending))
-                                               sh->ops.count++;
                                        s->locked++;
                                } else {
                                        set_bit(STRIPE_DELAYED, &sh->state);
@@ -2234,9 +2225,6 @@ static void handle_issuing_new_write_requests5(raid5_conf_t *conf,
                                                "%d for Reconstruct\n", i);
                                        set_bit(R5_LOCKED, &dev->flags);
                                        set_bit(R5_Wantread, &dev->flags);
-                                       if (!test_and_set_bit(
-                                               STRIPE_OP_IO, &sh->ops.pending))
-                                               sh->ops.count++;
                                        s->locked++;
                                } else {
                                        set_bit(STRIPE_DELAYED, &sh->state);
@@ -2444,8 +2432,6 @@ static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
 
                set_bit(R5_LOCKED, &dev->flags);
                set_bit(R5_Wantwrite, &dev->flags);
-               if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
-                       sh->ops.count++;
 
                clear_bit(STRIPE_DEGRADED, &sh->state);
                s->locked++;
@@ -2801,9 +2787,6 @@ static void handle_stripe5(struct stripe_head *sh)
                                (i == sh->pd_idx || dev->written)) {
                                pr_debug("Writing block %d\n", i);
                                set_bit(R5_Wantwrite, &dev->flags);
-                               if (!test_and_set_bit(
-                                   STRIPE_OP_IO, &sh->ops.pending))
-                                       sh->ops.count++;
                                if (prexor)
                                        continue;
                                if (!test_bit(R5_Insync, &dev->flags) ||
@@ -2857,16 +2840,12 @@ static void handle_stripe5(struct stripe_head *sh)
                dev = &sh->dev[s.failed_num];
                if (!test_bit(R5_ReWrite, &dev->flags)) {
                        set_bit(R5_Wantwrite, &dev->flags);
-                       if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
-                               sh->ops.count++;
                        set_bit(R5_ReWrite, &dev->flags);
                        set_bit(R5_LOCKED, &dev->flags);
                        s.locked++;
                } else {
                        /* let's read it back */
                        set_bit(R5_Wantread, &dev->flags);
-                       if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
-                               sh->ops.count++;
                        set_bit(R5_LOCKED, &dev->flags);
                        s.locked++;
                }
@@ -2884,13 +2863,10 @@ static void handle_stripe5(struct stripe_head *sh)
                clear_bit(STRIPE_OP_POSTXOR, &sh->ops.ack);
                clear_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
 
-               for (i = conf->raid_disks; i--; ) {
+               for (i = conf->raid_disks; i--; )
                        set_bit(R5_Wantwrite, &sh->dev[i].flags);
                        set_bit(R5_LOCKED, &dev->flags);
                        s.locked++;
-                       if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
-                               sh->ops.count++;
-               }
        }
 
        if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
@@ -2926,6 +2902,8 @@ static void handle_stripe5(struct stripe_head *sh)
        if (pending)
                raid5_run_ops(sh, pending);
 
+       ops_run_io(sh);
+
        return_io(return_bi);
 
 }

diff --git a/include/linux/raid/raid5.h b/include/linux/raid/raid5.h
index 4ecae31..1301195 100644 (file)
--- a/include/linux/raid/raid5.h
+++ b/include/linux/raid/raid5.h
@@ -263,7 +263,6 @@ struct r6_state {
 #define STRIPE_OP_BIODRAIN     3
 #define STRIPE_OP_POSTXOR      4
 #define STRIPE_OP_CHECK        5
-#define STRIPE_OP_IO           6
 
 /* modifiers to the base operations
  * STRIPE_OP_MOD_REPAIR_PD - compute the parity block and write it back