Patchwork [09/25] sheepdog: traverse pending_list from the first for each time

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Submitter Kevin Wolf
Date July 9, 2012, 2:16 p.m.
Message ID <1341843388-5663-10-git-send-email-kwolf@redhat.com>
Download mbox | patch
Permalink /patch/169886/
State New
Headers show

Comments

Kevin Wolf - July 9, 2012, 2:16 p.m.
From: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>

The pending list can be modified in other coroutine context
sd_co_rw_vector, so we need to traverse the list from the first again
after we send the pending request.

Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/sheepdog.c |   22 ++++++++++++++++------
 1 files changed, 16 insertions(+), 6 deletions(-)

Patch

diff --git a/block/sheepdog.c b/block/sheepdog.c
index f6cd517..6e73efb 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -634,21 +634,31 @@  static int coroutine_fn add_aio_request(BDRVSheepdogState *s, AIOReq *aio_req,
                            struct iovec *iov, int niov, int create,
                            enum AIOCBState aiocb_type);
 
+
+static AIOReq *find_pending_req(BDRVSheepdogState *s, uint64_t oid)
+{
+    AIOReq *aio_req;
+
+    QLIST_FOREACH(aio_req, &s->pending_aio_head, aio_siblings) {
+        if (aio_req->oid == oid) {
+            return aio_req;
+        }
+    }
+
+    return NULL;
+}
+
 /*
  * This function searchs pending requests to the object `oid', and
  * sends them.
  */
 static void coroutine_fn send_pending_req(BDRVSheepdogState *s, uint64_t oid)
 {
-    AIOReq *aio_req, *next;
+    AIOReq *aio_req;
     SheepdogAIOCB *acb;
     int ret;
 
-    QLIST_FOREACH_SAFE(aio_req, &s->pending_aio_head, aio_siblings, next) {
-        if (aio_req->oid != oid) {
-            continue;
-        }
-
+    while ((aio_req = find_pending_req(s, oid)) != NULL) {
         acb = aio_req->aiocb;
         /* move aio_req from pending list to inflight one */
         QLIST_REMOVE(aio_req, aio_siblings);