LU-11616 llite: replace smp_wb() with full memory barrier

[fs/lustre-release.git] / lustre / llite / statahead.c

diff --git a/lustre/llite/statahead.c b/lustre/llite/statahead.c
index 3977129..5c7dbb5 100644 (file)
--- a/lustre/llite/statahead.c
+++ b/lustre/llite/statahead.c
@@ -325,7 +325,11 @@ __sa_make_ready(struct ll_statahead_info *sai, struct sa_entry *entry, int ret)
                }
        }
        list_add(&entry->se_list, pos);
-       entry->se_state = ret < 0 ? SA_ENTRY_INVA : SA_ENTRY_SUCC;
+       /*
+        * LU-9210: ll_statahead_interpet must be able to see this before
+        * we wake it up
+        */
+       smp_store_release(&entry->se_state, ret < 0 ? SA_ENTRY_INVA : SA_ENTRY_SUCC);
 
        return (index == sai->sai_index_wait);
 }
@@ -767,7 +771,6 @@ static int ll_statahead_interpret(struct ptlrpc_request *req,
        }
        sai->sai_replied++;
 
-       smp_mb();
        if (waitq != NULL)
                wake_up(waitq);
        spin_unlock(&lli->lli_sa_lock);
@@ -1481,7 +1484,12 @@ static int revalidate_statahead_dentry(struct inode *dir,
                }
        }
 
-       if (entry->se_state == SA_ENTRY_SUCC && entry->se_inode != NULL) {
+       /*
+        * We need to see the value that was set immediately before we
+        * were woken up.
+        */
+       if (smp_load_acquire(&entry->se_state) == SA_ENTRY_SUCC &&
+           entry->se_inode) {
                struct inode *inode = entry->se_inode;
                struct lookup_intent it = { .it_op = IT_GETATTR,
                                            .it_lock_handle =