s3:smb2_lock: add retry for POSIX locks

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14113

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>

diff --git a/selftest/knownfail.d/smb2.localposixlock b/selftest/knownfail.d/smb2.localposixlock
deleted file mode 100644 (file)
index 1b84f07..0000000
--- a/selftest/knownfail.d/smb2.localposixlock
+++ /dev/null
@@ -1 +0,0 @@
-^samba3.smb2.samba3misc.localposixlock1

diff --git a/source3/smbd/smb2_lock.c b/source3/smbd/smb2_lock.c
index a8ccf21cc2004e6d1ed7071cb9803b0051a8f194..8ba54fe69953ce71e438f85d248f6a2b987f6ff3 100644 (file)
--- a/source3/smbd/smb2_lock.c
+++ b/source3/smbd/smb2_lock.c
@@ -43,6 +43,7 @@ struct smbd_smb2_lock_state {
        struct smb_request *smb1req;
        struct files_struct *fsp;
        bool blocking;
+       uint32_t polling_msecs;
        uint16_t lock_count;
        struct smbd_lock_element *locks;
 };
@@ -371,6 +372,32 @@ static struct tevent_req *smbd_smb2_lock_send(TALLOC_CTX *mem_ctx,
        return req;
 }
 
+static void smbd_smb2_lock_update_polling_msecs(
+       struct smbd_smb2_lock_state *state)
+{
+       /*
+        * The default lp_lock_spin_time() is 200ms.
+        *
+        * v_min is in the range of 0.002 to 20 secs
+        * (0.2 secs by default)
+        *
+        * v_max is in the range of 0.02 to 200 secs
+        * (2.0 secs by default)
+        *
+        * The typical steps are:
+        * 0.2, 0.4, 0.6, 0.8, ... 2.0
+        */
+       uint32_t v_min = MAX(2, MIN(20000, lp_lock_spin_time()));
+       uint32_t v_max = 10 * v_min;
+
+       if (state->polling_msecs >= v_max) {
+               state->polling_msecs = v_max;
+               return;
+       }
+
+       state->polling_msecs += v_min;
+}
+
 static void smbd_smb2_lock_try(struct tevent_req *req)
 {
        struct smbd_smb2_lock_state *state = tevent_req_data(
@@ -381,6 +408,7 @@ static void smbd_smb2_lock_try(struct tevent_req *req)
        uint64_t blocking_smblctx;
        NTSTATUS status;
        struct tevent_req *subreq = NULL;
+       struct timeval endtime = { 0 };
 
        lck = get_existing_share_mode_lock(
                talloc_tos(), state->fsp->file_id);
@@ -426,6 +454,15 @@ static void smbd_smb2_lock_try(struct tevent_req *req)
                return;
        }
 
+       if (blocking_smblctx == UINT64_MAX) {
+               smbd_smb2_lock_update_polling_msecs(state);
+
+               DBG_DEBUG("Blocked on a posix lock. Retry in %"PRIu32" msecs\n",
+                         state->polling_msecs);
+
+               endtime = timeval_current_ofs_msec(state->polling_msecs);
+       }
+
        DBG_DEBUG("Watching share mode lock\n");
 
        subreq = dbwrap_watched_watch_send(
@@ -435,6 +472,18 @@ static void smbd_smb2_lock_try(struct tevent_req *req)
                return;
        }
        tevent_req_set_callback(subreq, smbd_smb2_lock_retry, req);
+
+       if (!timeval_is_zero(&endtime)) {
+               bool ok;
+
+               ok = tevent_req_set_endtime(subreq,
+                                           state->ev,
+                                           endtime);
+               if (!ok) {
+                       tevent_req_oom(req);
+                       return;
+               }
+       }
 }
 
 static void smbd_smb2_lock_retry(struct tevent_req *subreq)
@@ -457,6 +506,12 @@ static void smbd_smb2_lock_retry(struct tevent_req *subreq)
 
        status = dbwrap_watched_watch_recv(subreq, NULL, NULL);
        TALLOC_FREE(subreq);
+       if (NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT)) {
+               /*
+                * This is just a trigger for a timed retry.
+                */
+               status = NT_STATUS_OK;
+       }
        if (tevent_req_nterror(req, status)) {
                return;
        }