LU-11851 ldiskfs: reschedule for htree thread.

[fs/lustre-release.git] / ldiskfs / kernel_patches / patches / rhel7.4 / ext4-pdirop.patch

diff --git a/ldiskfs/kernel_patches/patches/rhel7.4/ext4-pdirop.patch b/ldiskfs/kernel_patches/patches/rhel7.4/ext4-pdirop.patch
index 72788c8..910a495 100644 (file)
--- a/ldiskfs/kernel_patches/patches/rhel7.4/ext4-pdirop.patch
+++ b/ldiskfs/kernel_patches/patches/rhel7.4/ext4-pdirop.patch
@@ -9,7 +9,7 @@ an entire ldiskfs directory. PDO project will remove this
 bottleneck by introducing a parallel locking mechanism for entire
 ldiskfs directories. This work will enable multiple application
 threads to simultaneously lookup, create and unlink in parallel.
-    
+
 This patch contains:
  - pdirops support for ldiskfs
  - integrate with osd-ldiskfs
@@ -210,7 +210,7 @@ Index: linux-3.10.0-229.1.2.fc21.x86_64/fs/ext4/htree_lock.c
 ===================================================================
 --- /dev/null
 +++ linux-3.10.0-229.1.2.fc21.x86_64/fs/ext4/htree_lock.c
-@@ -0,0 +1,880 @@
+@@ -0,0 +1,891 @@
 +/*
 + * fs/ext4/htree_lock.c
 + *
@@ -852,12 +852,23 @@ Index: linux-3.10.0-229.1.2.fc21.x86_64/fs/ext4/htree_lock.c
 +              lck->lk_task = current;
 +              list_add_tail(&lck->lk_blocked_list, &lhead->lh_blocked_list);
 +
++retry:
 +              set_current_state(TASK_UNINTERRUPTIBLE);
 +              htree_spin_unlock(lhead, HTREE_DEP_ROOT);
 +              /* wait to be given the lock */
 +              if (lck->lk_task != NULL)
 +                      schedule();
-+              /* granted, no doubt. wake up will set me RUNNING */
++              /* granted, no doubt. wake up will set me RUNNING.
++               * Since thread would be waken up accidentally,
++               * so we need check lock whether granted or not again. */
++              if (!list_empty(&lck->lk_blocked_list)) {
++                      htree_spin_lock(lhead, HTREE_DEP_ROOT);
++                      if (list_empty(&lck->lk_blocked_list)) {
++                              htree_spin_unlock(lhead, HTREE_DEP_ROOT);
++                              return 0;
++                      }
++                      goto retry;
++              }
 +              return 0; /* without lh_lock */
 +      }
 +      lhead->lh_ngranted[lck->lk_mode]++;