md/raid5: move some more common code into handle_stripe

The RAID6 version of this code is usable for RAID5 providing:
  - we test "conf->max_degraded" rather than "2" as appropriate
  - we make sure s->failed_num[1] is meaningful (and not '-1')
    when s->failed > 1

The 'return 1' must become 'goto finish' in the new location.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>

1 files changed, 67 insertions, 113 deletions

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index cf60b15b4e3a..63acc51e8406 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2968,63 +2968,14 @@ static int handle_stripe5(struct stripe_head *sh, struct stripe_head_state *s)
                 if (test_bit(R5_ReadError, &dev->flags))
                         clear_bit(R5_Insync, &dev->flags);
                 if (!test_bit(R5_Insync, &dev->flags)) {
+                        if (s->failed < 2)
+                                s->failed_num[s->failed] = i;
                         s->failed++;
-                        s->failed_num[0] = i;
                 }
         }
         spin_unlock_irq(&conf->device_lock);
         rcu_read_unlock();
 
-        if (unlikely(s->blocked_rdev)) {
-                if (s->syncing || s->expanding || s->expanded ||
-                    s->to_write || s->written) {
-                        set_bit(STRIPE_HANDLE, &sh->state);
-                        return 1;
-                }
-                /* There is nothing for the blocked_rdev to block */
-                rdev_dec_pending(s->blocked_rdev, conf->mddev);
-                s->blocked_rdev = NULL;
-        }
-
-        if (s->to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
-                set_bit(STRIPE_OP_BIOFILL, &s->ops_request);
-                set_bit(STRIPE_BIOFILL_RUN, &sh->state);
-        }
-
-        pr_debug("locked=%d uptodate=%d to_read=%d"
-                " to_write=%d failed=%d failed_num=%d\n",
-                s->locked, s->uptodate, s->to_read, s->to_write,
-                s->failed, s->failed_num[0]);
-        /* check if the array has lost two devices and, if so, some requests might
-         * need to be failed
-         */
-        if (s->failed > 1 && s->to_read+s->to_write+s->written)
-                handle_failed_stripe(conf, sh, s, disks, &s->return_bi);
-        if (s->failed > 1 && s->syncing) {
-                md_done_sync(conf->mddev, STRIPE_SECTORS,0);
-                clear_bit(STRIPE_SYNCING, &sh->state);
-                s->syncing = 0;
-        }
-
-        /* might be able to return some write requests if the parity block
-         * is safe, or on a failed drive
-         */
-        dev = &sh->dev[sh->pd_idx];
-        if (s->written &&
-            ((test_bit(R5_Insync, &dev->flags) &&
-              !test_bit(R5_LOCKED, &dev->flags) &&
-              test_bit(R5_UPTODATE, &dev->flags)) ||
-             (s->failed == 1 && s->failed_num[0] == sh->pd_idx)))
-                handle_stripe_clean_event(conf, sh, disks, &s->return_bi);
-
-        /* Now we might consider reading some blocks, either to check/generate
-         * parity, or to satisfy requests
-         * or to load a block that is being partially written.
-         */
-        if (s->to_read || s->non_overwrite ||
-            (s->syncing && (s->uptodate + s->compute < disks)) || s->expanding)
-                handle_stripe_fill(sh, s, disks);
-
         return 0;
 }
 
@@ -3032,8 +2983,8 @@ static int handle_stripe6(struct stripe_head *sh, struct stripe_head_state *s)
 {
         raid5_conf_t *conf = sh->raid_conf;
         int disks = sh->disks;
-        int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx;
-        struct r5dev *dev, *pdev, *qdev;
+        struct r5dev *dev;
+        int i;
 
         /* Now to look around and see what can be done */
 
@@ -3107,65 +3058,6 @@ static int handle_stripe6(struct stripe_head *sh, struct stripe_head_state *s)
         spin_unlock_irq(&conf->device_lock);
         rcu_read_unlock();
 
-        if (unlikely(s->blocked_rdev)) {
-                if (s->syncing || s->expanding || s->expanded ||
-                    s->to_write || s->written) {
-                        set_bit(STRIPE_HANDLE, &sh->state);
-                        return 1;
-                }
-                /* There is nothing for the blocked_rdev to block */
-                rdev_dec_pending(s->blocked_rdev, conf->mddev);
-                s->blocked_rdev = NULL;
-        }
-
-        if (s->to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
-                set_bit(STRIPE_OP_BIOFILL, &s->ops_request);
-                set_bit(STRIPE_BIOFILL_RUN, &sh->state);
-        }
-
-        pr_debug("locked=%d uptodate=%d to_read=%d"
-               " to_write=%d failed=%d failed_num=%d,%d\n",
-               s->locked, s->uptodate, s->to_read, s->to_write, s->failed,
-               s->failed_num[0], s->failed_num[1]);
-        /* check if the array has lost >2 devices and, if so, some requests
-         * might need to be failed
-         */
-        if (s->failed > 2 && s->to_read+s->to_write+s->written)
-                handle_failed_stripe(conf, sh, s, disks, &s->return_bi);
-        if (s->failed > 2 && s->syncing) {
-                md_done_sync(conf->mddev, STRIPE_SECTORS,0);
-                clear_bit(STRIPE_SYNCING, &sh->state);
-                s->syncing = 0;
-        }
-
-        /*
-         * might be able to return some write requests if the parity blocks
-         * are safe, or on a failed drive
-         */
-        pdev = &sh->dev[pd_idx];
-        s->p_failed = (s->failed >= 1 && s->failed_num[0] == pd_idx)
-                || (s->failed >= 2 && s->failed_num[1] == pd_idx);
-        qdev = &sh->dev[qd_idx];
-        s->q_failed = (s->failed >= 1 && s->failed_num[0] == qd_idx)
-                || (s->failed >= 2 && s->failed_num[1] == qd_idx);
-
-        if (s->written &&
-            (s->p_failed || ((test_bit(R5_Insync, &pdev->flags)
-                             && !test_bit(R5_LOCKED, &pdev->flags)
-                             && test_bit(R5_UPTODATE, &pdev->flags)))) &&
-            (s->q_failed || ((test_bit(R5_Insync, &qdev->flags)
-                             && !test_bit(R5_LOCKED, &qdev->flags)
-                             && test_bit(R5_UPTODATE, &qdev->flags)))))
-                handle_stripe_clean_event(conf, sh, disks, &s->return_bi);
-
-        /* Now we might consider reading some blocks, either to check/generate
-         * parity, or to satisfy requests
-         * or to load a block that is being partially written.
-         */
-        if (s->to_read || s->non_overwrite || (s->to_write && s->failed) ||
-            (s->syncing && (s->uptodate + s->compute < disks)) || s->expanding)
-                handle_stripe_fill(sh, s, disks);
-
         return 0;
 }
 
@@ -3173,10 +3065,11 @@ static void handle_stripe(struct stripe_head *sh)
 {
         struct stripe_head_state s;
         int done;
+        raid5_conf_t *conf = sh->raid_conf;
         int i;
         int prexor;
         int disks = sh->disks;
-        raid5_conf_t *conf = sh->raid_conf;
+        struct r5dev *pdev, *qdev;
 
         clear_bit(STRIPE_HANDLE, &sh->state);
         if (test_and_set_bit(STRIPE_ACTIVE, &sh->state)) {
@@ -3213,6 +3106,67 @@ static void handle_stripe(struct stripe_head *sh)
         if (done)
                 goto finish;
 
+        if (unlikely(s.blocked_rdev)) {
+                if (s.syncing || s.expanding || s.expanded ||
+                    s.to_write || s.written) {
+                        set_bit(STRIPE_HANDLE, &sh->state);
+                        goto finish;
+                }
+                /* There is nothing for the blocked_rdev to block */
+                rdev_dec_pending(s.blocked_rdev, conf->mddev);
+                s.blocked_rdev = NULL;
+        }
+
+        if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
+                set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
+                set_bit(STRIPE_BIOFILL_RUN, &sh->state);
+        }
+
+        pr_debug("locked=%d uptodate=%d to_read=%d"
+               " to_write=%d failed=%d failed_num=%d,%d\n",
+               s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
+               s.failed_num[0], s.failed_num[1]);
+        /* check if the array has lost more than max_degraded devices and,
+         * if so, some requests might need to be failed.
+         */
+        if (s.failed > conf->max_degraded && s.to_read+s.to_write+s.written)
+                handle_failed_stripe(conf, sh, &s, disks, &s.return_bi);
+        if (s.failed > conf->max_degraded && s.syncing) {
+                md_done_sync(conf->mddev, STRIPE_SECTORS, 0);
+                clear_bit(STRIPE_SYNCING, &sh->state);
+                s.syncing = 0;
+        }
+
+        /*
+         * might be able to return some write requests if the parity blocks
+         * are safe, or on a failed drive
+         */
+        pdev = &sh->dev[sh->pd_idx];
+        s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx)
+                || (s.failed >= 2 && s.failed_num[1] == sh->pd_idx);
+        qdev = &sh->dev[sh->qd_idx];
+        s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx)
+                || (s.failed >= 2 && s.failed_num[1] == sh->qd_idx)
+                || conf->level < 6;
+
+        if (s.written &&
+            (s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
+                             && !test_bit(R5_LOCKED, &pdev->flags)
+                             && test_bit(R5_UPTODATE, &pdev->flags)))) &&
+            (s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
+                             && !test_bit(R5_LOCKED, &qdev->flags)
+                             && test_bit(R5_UPTODATE, &qdev->flags)))))
+                handle_stripe_clean_event(conf, sh, disks, &s.return_bi);
+
+        /* Now we might consider reading some blocks, either to check/generate
+         * parity, or to satisfy requests
+         * or to load a block that is being partially written.
+         */
+        if (s.to_read || s.non_overwrite
+            || (conf->level == 6 && s.to_write && s.failed)
+            || (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
+                handle_stripe_fill(sh, &s, disks);
+
         /* Now we check to see if any write operations have recently
          * completed
          */