handle_stripe6 function is changed to do things asynchronously.

Signed-off-by: Yuri Tikhonov <[EMAIL PROTECTED]>
Signed-off-by: Ilya Yanok <[EMAIL PROTECTED]>
---
 drivers/md/raid5.c |  130 ++++++++++++++++++++++++++++++++++++----------------
 1 files changed, 90 insertions(+), 40 deletions(-)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 963bc4b..79e8c74 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3119,9 +3119,10 @@ static bool handle_stripe6(struct stripe_head *sh, 
struct page *tmp_page)
 
        r6s.qd_idx = raid6_next_disk(pd_idx, disks);
        pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
-               "pd_idx=%d, qd_idx=%d\n",
+               "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
               (unsigned long long)sh->sector, sh->state,
-              atomic_read(&sh->count), pd_idx, r6s.qd_idx);
+              atomic_read(&sh->count), pd_idx, r6s.qd_idx,
+              sh->check_state, sh->reconstruct_state);
        memset(&s, 0, sizeof(s));
 
        spin_lock(&sh->lock);
@@ -3141,35 +3142,24 @@ static bool handle_stripe6(struct stripe_head *sh, 
struct page *tmp_page)
 
                pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
                        i, dev->flags, dev->toread, dev->towrite, dev->written);
-               /* maybe we can reply to a read */
-               if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
-                       struct bio *rbi, *rbi2;
-                       pr_debug("Return read for disc %d\n", i);
-                       spin_lock_irq(&conf->device_lock);
-                       rbi = dev->toread;
-                       dev->toread = NULL;
-                       if (test_and_clear_bit(R5_Overlap, &dev->flags))
-                               wake_up(&conf->wait_for_overlap);
-                       spin_unlock_irq(&conf->device_lock);
-                       while (rbi && rbi->bi_sector < dev->sector + 
STRIPE_SECTORS) {
-                               copy_data(0, rbi, dev->page, dev->sector);
-                               rbi2 = r5_next_bio(rbi, dev->sector);
-                               spin_lock_irq(&conf->device_lock);
-                               if (!raid5_dec_bi_phys_segments(rbi)) {
-                                       rbi->bi_next = return_bi;
-                                       return_bi = rbi;
-                               }
-                               spin_unlock_irq(&conf->device_lock);
-                               rbi = rbi2;
-                       }
-               }
+               /* maybe we can reply to a read
+                *
+                * new wantfill requests are only permitted while
+                * ops_complete_biofill is guaranteed to be inactive
+                */
+               if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
+                   !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
+                       set_bit(R5_Wantfill, &dev->flags);
 
                /* now count some things */
                if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
                if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
+               if (test_bit(R5_Wantcompute, &dev->flags))
+                       BUG_ON(++s.compute > 2);
 
-
-               if (dev->toread)
+               if (test_bit(R5_Wantfill, &dev->flags)) {
+                       s.to_fill++;
+               } else if (dev->toread)
                        s.to_read++;
                if (dev->towrite) {
                        s.to_write++;
@@ -3210,6 +3200,11 @@ static bool handle_stripe6(struct stripe_head *sh, 
struct page *tmp_page)
                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,
@@ -3250,18 +3245,62 @@ static bool handle_stripe6(struct stripe_head *sh, 
struct page *tmp_page)
         * 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 < disks)) || s.expanding)
+           (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
                handle_stripe_fill6(sh, &s, &r6s, disks);
 
-       /* now to consider writing and what else, if anything should be read */
-       if (s.to_write)
+       /* Now we check to see if any write operations have recently
+        * completed
+        */
+       if (sh->reconstruct_state == reconstruct_state_drain_result) {
+               int qd_idx = raid6_next_disk(sh->pd_idx,
+                                            conf->raid_disks);
+
+               sh->reconstruct_state = reconstruct_state_idle;
+               /* All the 'written' buffers and the parity blocks are ready to
+                * be written back to disk
+                */
+               BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
+               BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[qd_idx].flags));
+               for (i = disks; i--; ) {
+                       dev = &sh->dev[i];
+                       if (test_bit(R5_LOCKED, &dev->flags) &&
+                           (i == sh->pd_idx || i == qd_idx ||
+                            dev->written)) {
+                               pr_debug("Writing block %d\n", i);
+                               BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
+                               set_bit(R5_Wantwrite, &dev->flags);
+                               if (!test_bit(R5_Insync, &dev->flags) ||
+                                   ((i == sh->pd_idx || i == qd_idx) &&
+                                     s.failed == 0))
+                                       set_bit(STRIPE_INSYNC, &sh->state);
+                       }
+               }
+               if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
+                       atomic_dec(&conf->preread_active_stripes);
+                       if (atomic_read(&conf->preread_active_stripes) <
+                               IO_THRESHOLD)
+                               md_wakeup_thread(conf->mddev->thread);
+               }
+       }
+
+       /* Now to consider new write requests and what else, if anything
+        * should be read.  We do not handle new writes when:
+        * 1/ A 'write' operation (copy+xor) is already in flight.
+        * 2/ A 'check' operation is in flight, as it may clobber the parity
+        *    block.
+        */
+       if (s.to_write && !sh->reconstruct_state && !sh->check_state)
                handle_stripe_dirtying6(conf, sh, &s, &r6s, disks);
 
        /* maybe we need to check and possibly fix the parity for this stripe
         * Any reads will already have been scheduled, so we just see if enough
-        * data is available
+        * data is available.  The parity check is held off while parity
+        * dependent operations are in flight.
         */
-       if (s.syncing && s.locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state))
+       if (sh->check_state ||
+           (s.syncing && s.locked == 0 &&
+            !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
+            !test_bit(STRIPE_INSYNC, &sh->state)))
                handle_parity_checks6(conf, sh, &s, &r6s, tmp_page, disks);
 
        if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
@@ -3283,27 +3322,35 @@ static bool handle_stripe6(struct stripe_head *sh, 
struct page *tmp_page)
                                        set_bit(R5_Wantwrite, &dev->flags);
                                        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);
                                        set_bit(R5_LOCKED, &dev->flags);
+                                       s.locked++;
                                }
                        }
                }
 
-       if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
+       /* Finish reconstruct operations initiated by the expansion process */
+       if (sh->reconstruct_state == reconstruct_state_result) {
+               sh->reconstruct_state = reconstruct_state_idle;
+               clear_bit(STRIPE_EXPANDING, &sh->state);
+               for (i = conf->raid_disks; i--; ) {
+                       set_bit(R5_Wantwrite, &sh->dev[i].flags);
+                       set_bit(R5_LOCKED, &sh->dev[i].flags);
+                       s.locked++;
+               }
+       }
+
+       if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
+           !sh->reconstruct_state) {
                /* Need to write out all blocks after computing P&Q */
                sh->disks = conf->raid_disks;
                sh->pd_idx = stripe_to_pdidx(sh->sector, conf,
                                             conf->raid_disks);
-               compute_parity6(sh, RECONSTRUCT_WRITE);
-               for (i = conf->raid_disks ; i-- ;  ) {
-                       set_bit(R5_LOCKED, &sh->dev[i].flags);
-                       s.locked++;
-                       set_bit(R5_Wantwrite, &sh->dev[i].flags);
-               }
-               clear_bit(STRIPE_EXPANDING, &sh->state);
-       } else if (s.expanded) {
+               schedule_reconstruction(sh, &s, 1, 1);
+       } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
                clear_bit(STRIPE_EXPAND_READY, &sh->state);
                atomic_dec(&conf->reshape_stripes);
                wake_up(&conf->wait_for_overlap);
@@ -3321,6 +3368,9 @@ static bool handle_stripe6(struct stripe_head *sh, struct 
page *tmp_page)
        if (unlikely(blocked_rdev))
                md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
 
+       if (s.ops_request)
+               raid_run_ops(sh, s.ops_request);
+
        ops_run_io(sh, &s);
 
        return_io(return_bi);
-- 
1.5.6.1

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