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authorVolker Lendecke <vl@samba.org>2012-01-13 13:26:41 +0100
committerVolker Lendecke <vlendec@samba.org>2012-01-18 14:48:04 +0100
commitcf77a21c633807b178fb716dba7a6284cca58511 (patch)
tree9a697989fc9089b38ba0f08fcdba9b70bc75bf8a
parent333c92384b0680b8f8e5198dd68d49b249b34ec7 (diff)
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s3: Change locking order between brlock and locking
But 8175 was fixed in a way that brlock.tdb was always locked before locking.tdb. This patch fixes the bug in a different way. locking.tdb is the central tdb for files and should always be locked first. This patch solves the problem by postponing the level2 break messages, which are async anyway.
-rw-r--r--source3/smbd/oplock.c66
1 files changed, 58 insertions, 8 deletions
diff --git a/source3/smbd/oplock.c b/source3/smbd/oplock.c
index 2197c7947f..0c4155d9d6 100644
--- a/source3/smbd/oplock.c
+++ b/source3/smbd/oplock.c
@@ -735,6 +735,12 @@ static void process_open_retry_message(struct messaging_context *msg_ctx,
schedule_deferred_open_message_smb(sconn, msg.op_mid);
}
+struct break_to_none_state {
+ struct smbd_server_connection *sconn;
+ struct file_id id;
+};
+static void do_break_to_none(struct tevent_req *req);
+
/****************************************************************************
This function is called on any file modification or lock request. If a file
is level 2 oplocked then it must tell all other level 2 holders to break to
@@ -744,8 +750,9 @@ static void process_open_retry_message(struct messaging_context *msg_ctx,
static void contend_level2_oplocks_begin_default(files_struct *fsp,
enum level2_contention_type type)
{
- int i;
- struct share_mode_lock *lck;
+ struct smbd_server_connection *sconn = fsp->conn->sconn;
+ struct tevent_req *req;
+ struct break_to_none_state *state;
/*
* If this file is level II oplocked then we need
@@ -758,12 +765,52 @@ static void contend_level2_oplocks_begin_default(files_struct *fsp,
if (!LEVEL_II_OPLOCK_TYPE(fsp->oplock_type))
return;
- lck = get_share_mode_lock(talloc_tos(), fsp->file_id);
- if (lck == NULL) {
- DEBUG(0,("release_level_2_oplocks_on_change: failed to lock "
- "share mode entry for file %s.\n", fsp_str_dbg(fsp)));
+ /*
+ * When we get here we might have a brlock entry locked. Also
+ * locking the share mode entry would violate the locking
+ * order. Breaking level2 oplocks to none is asynchronous
+ * anyway, so we postpone this into an immediate timed event.
+ */
+
+ state = talloc(sconn, struct break_to_none_state);
+ if (state == NULL) {
+ DEBUG(1, ("talloc failed\n"));
+ return;
+ }
+ state->sconn = sconn;
+ state->id = fsp->file_id;
+
+ req = tevent_wakeup_send(state, sconn->ev_ctx, timeval_set(0, 0));
+ if (req == NULL) {
+ DEBUG(1, ("tevent_wakeup_send failed\n"));
+ TALLOC_FREE(state);
return;
}
+ tevent_req_set_callback(req, do_break_to_none, state);
+ return;
+}
+
+static void do_break_to_none(struct tevent_req *req)
+{
+ struct break_to_none_state *state = tevent_req_callback_data(
+ req, struct break_to_none_state);
+ bool ret;
+ int i;
+ struct share_mode_lock *lck;
+
+ ret = tevent_wakeup_recv(req);
+ TALLOC_FREE(req);
+ if (!ret) {
+ DEBUG(1, ("tevent_wakeup_recv failed\n"));
+ goto done;
+ }
+ lck = get_share_mode_lock(talloc_tos(), state->id);
+ if (lck == NULL) {
+ DEBUG(1, ("release_level_2_oplocks_on_change: failed to lock "
+ "share mode entry for file %s.\n",
+ file_id_string_tos(&state->id)));
+ goto done;
+ }
DEBUG(10,("release_level_2_oplocks_on_change: num_share_modes = %d\n",
lck->data->num_share_modes ));
@@ -820,7 +867,7 @@ static void contend_level2_oplocks_begin_default(files_struct *fsp,
if (procid_is_me(&share_entry->pid)) {
struct files_struct *cur_fsp =
- initial_break_processing(fsp->conn->sconn,
+ initial_break_processing(state->sconn,
share_entry->id,
share_entry->share_file_id);
wait_before_sending_break();
@@ -831,7 +878,7 @@ static void contend_level2_oplocks_begin_default(files_struct *fsp,
"Did not find fsp, ignoring\n"));
}
} else {
- messaging_send_buf(fsp->conn->sconn->msg_ctx,
+ messaging_send_buf(state->sconn->msg_ctx,
share_entry->pid,
MSG_SMB_ASYNC_LEVEL2_BREAK,
(uint8 *)msg,
@@ -843,6 +890,9 @@ static void contend_level2_oplocks_begin_default(files_struct *fsp,
in the share mode lock db. */
TALLOC_FREE(lck);
+done:
+ TALLOC_FREE(state);
+ return;
}
void smbd_contend_level2_oplocks_begin(files_struct *fsp,