summaryrefslogtreecommitdiff
path: root/fs/btrfs/async-thread.c
diff options
context:
space:
mode:
authorJason Gunthorpe <jgg@nvidia.com>2021-12-14 20:18:48 -0400
committerJason Gunthorpe <jgg@nvidia.com>2021-12-14 20:18:48 -0400
commit4922f0920966c28d674b03479cdcb7f3939bfbbd (patch)
tree6a8b3972ff853fc0addcfab662d33354124f7fdb /fs/btrfs/async-thread.c
parent20679094a0161c94faf77e373fa3f7428a8e14bd (diff)
parent2585cf9dfaaddf00b069673f27bb3f8530e2039c (diff)
Merge tag 'v5.16-rc5' into rdma.git for-next
Required due to dependencies in following patches. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'fs/btrfs/async-thread.c')
-rw-r--r--fs/btrfs/async-thread.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
index 309516e6a968..43c89952b7d2 100644
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -234,6 +234,13 @@ static void run_ordered_work(struct __btrfs_workqueue *wq,
ordered_list);
if (!test_bit(WORK_DONE_BIT, &work->flags))
break;
+ /*
+ * Orders all subsequent loads after reading WORK_DONE_BIT,
+ * paired with the smp_mb__before_atomic in btrfs_work_helper
+ * this guarantees that the ordered function will see all
+ * updates from ordinary work function.
+ */
+ smp_rmb();
/*
* we are going to call the ordered done function, but
@@ -317,6 +324,13 @@ static void btrfs_work_helper(struct work_struct *normal_work)
thresh_exec_hook(wq);
work->func(work);
if (need_order) {
+ /*
+ * Ensures all memory accesses done in the work function are
+ * ordered before setting the WORK_DONE_BIT. Ensuring the thread
+ * which is going to executed the ordered work sees them.
+ * Pairs with the smp_rmb in run_ordered_work.
+ */
+ smp_mb__before_atomic();
set_bit(WORK_DONE_BIT, &work->flags);
run_ordered_work(wq, work);
} else {