From e6918187568dbd01842d8d1d2c808ce16a894239 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 21 Apr 2024 13:54:28 +0200
Subject: Adding upstream version 18.2.2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 src/client/Delegation.cc | 131 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 131 insertions(+)
 create mode 100644 src/client/Delegation.cc

(limited to 'src/client/Delegation.cc')

diff --git a/src/client/Delegation.cc b/src/client/Delegation.cc
new file mode 100644
index 000000000..0c0ac1b35
--- /dev/null
+++ b/src/client/Delegation.cc
@@ -0,0 +1,131 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+#include "common/Clock.h"
+#include "common/Timer.h"
+
+#include "Client.h"
+#include "Inode.h"
+#include "Fh.h"
+#include "Delegation.h"
+
+class C_Deleg_Timeout : public Context {
+  Delegation *deleg;
+public:
+  explicit C_Deleg_Timeout(Delegation *d) : deleg(d) {}
+  void finish(int r) override {
+    Inode *in = deleg->get_fh()->inode.get();
+    Client *client = in->client;
+
+    lsubdout(client->cct, client, 0) << __func__ <<
+	  ": delegation return timeout for inode 0x" <<
+	  std::hex << in->ino << ". Forcibly unmounting client. "<<
+	  client << std::dec << dendl;
+    client->_unmount(false);
+  }
+};
+
+/**
+ * ceph_deleg_caps_for_type - what caps are necessary for a delegation?
+ * @type: delegation request type
+ *
+ * Determine what caps are necessary in order to grant a delegation of a given
+ * type. For read delegations, we need whatever we require in order to do
+ * cached reads, plus AsLs to cover metadata changes that should trigger a
+ * recall. We also grab Xs since changing xattrs usually alters the mtime and
+ * so would trigger a recall.
+ *
+ * For write delegations, we need whatever read delegations need plus the
+ * caps to allow writing to the file (Fbwx).
+ */
+int ceph_deleg_caps_for_type(unsigned type)
+{
+	int caps = CEPH_CAP_PIN;
+
+	switch (type) {
+	case CEPH_DELEGATION_WR:
+		caps |= CEPH_CAP_FILE_EXCL |
+			CEPH_CAP_FILE_WR | CEPH_CAP_FILE_BUFFER;
+		/* Fallthrough */
+	case CEPH_DELEGATION_RD:
+		caps |= CEPH_CAP_FILE_SHARED |
+			CEPH_CAP_FILE_RD | CEPH_CAP_FILE_CACHE |
+			CEPH_CAP_XATTR_SHARED |
+			CEPH_CAP_LINK_SHARED | CEPH_CAP_AUTH_SHARED;
+		break;
+	default:
+		// Should never happen
+		ceph_abort();
+	}
+	return caps;
+}
+
+/*
+ * A delegation is a container for holding caps on behalf of a client that
+ * wants to be able to rely on them until recalled.
+ */
+Delegation::Delegation(Fh *_fh, unsigned _type, ceph_deleg_cb_t _cb, void *_priv)
+	: fh(_fh), priv(_priv), type(_type), recall_cb(_cb),
+	  recall_time(utime_t()), timeout_event(nullptr)
+{
+  Inode *inode = _fh->inode.get();
+  inode->client->get_cap_ref(inode, ceph_deleg_caps_for_type(_type));
+};
+
+Delegation::~Delegation()
+{
+  disarm_timeout();
+  Inode *inode = fh->inode.get();
+  inode->client->put_cap_ref(inode, ceph_deleg_caps_for_type(type));
+}
+
+void Delegation::reinit(unsigned _type, ceph_deleg_cb_t _recall_cb, void *_priv)
+{
+  /* update cap refs -- note that we do a get first to avoid any going to 0 */
+  if (type != _type) {
+    Inode *inode = fh->inode.get();
+
+    inode->client->get_cap_ref(inode, ceph_deleg_caps_for_type(_type));
+    inode->client->put_cap_ref(inode, ceph_deleg_caps_for_type(type));
+    type = _type;
+  }
+
+  recall_cb = _recall_cb;
+  priv = _priv;
+}
+
+void Delegation::arm_timeout()
+{
+  Client *client = fh->inode.get()->client;
+
+  std::scoped_lock l(client->timer_lock);
+  if (timeout_event)
+    return;
+
+  timeout_event = new C_Deleg_Timeout(this);
+  client->timer.add_event_after(client->get_deleg_timeout(), timeout_event);
+}
+
+void Delegation::disarm_timeout()
+{
+  Client *client = fh->inode.get()->client;
+
+  std::scoped_lock l(client->timer_lock);
+  if (!timeout_event)
+    return;
+
+  client->timer.cancel_event(timeout_event);
+  timeout_event = nullptr;
+}
+
+void Delegation::recall(bool skip_read)
+{
+  /* If skip_read is true, don't break read delegations */
+  if (skip_read && type == CEPH_DELEGATION_RD)
+    return;
+
+  if (!is_recalled()) {
+    recall_cb(fh, priv);
+    recall_time = ceph_clock_now();
+    arm_timeout();
+  }
+}
-- 
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