Import ceph 15.2.8

[ceph.git] / ceph / src / include / krbd.h

diff --git a/ceph/src/include/krbd.h b/ceph/src/include/krbd.h
index 2c63bc7ea54aa0cdfe1334239dd7f0fe8cc55134..977d45fe2e360c046638633cab85f27b63822169 100644 (file)
--- a/ceph/src/include/krbd.h
+++ b/ceph/src/include/krbd.h
@@ -15,13 +15,46 @@
 
 #include "rados/librados.h"
 
+/*
+ * Don't wait for udev add uevents in krbd_map() and udev remove
+ * uevents in krbd_unmap*().  Instead, make do with the respective
+ * kernel uevents and return as soon as they are received.
+ *
+ * systemd-udevd sends out udev uevents after it finishes processing
+ * the respective kernel uevents, which mostly boils down to executing
+ * all matching udev rules.  With this flag set, on return from
+ * krbd_map() systemd-udevd may still be poking at the device: it
+ * may still be open with tools such as blkid and various ioctls to
+ * be run against it, none of the persistent symlinks to the device
+ * node may be there, etc.  udev used to be responsible for creating
+ * the device node as well, but that has been handled by devtmpfs in
+ * the kernel for many years now, so the device node (as returned
+ * through @pdevnode) is guaranteed to be there.
+ *
+ * If set, krbd_map() and krbd_unmap*() can be invoked from any
+ * network namespace that is owned by the initial user namespace
+ * (which is a formality because things like loading kernel modules
+ * and creating block devices are not namespaced and require global
+ * privileges, i.e. capabilities in the initial user namespace).
+ * Otherwise, krbd_map() and krbd_unmap*() must be invoked from
+ * the initial network namespace.
+ *
+ * If set, krbd_unmap*() doesn't attempt to settle the udev queue
+ * before retrying unmap for the last time.  Some EBUSY errors due
+ * to systemd-udevd poking at the device at the time krbd_unmap*()
+ * is invoked that are otherwise covered by the retry logic may be
+ * returned.
+ */
+#define KRBD_CTX_F_NOUDEV       (1U << 0)
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 struct krbd_ctx;
 
-int krbd_create_from_context(rados_config_t cct, struct krbd_ctx **pctx);
+int krbd_create_from_context(rados_config_t cct, uint32_t flags,
+                             struct krbd_ctx **pctx);
 void krbd_destroy(struct krbd_ctx *ctx);
 
 int krbd_map(struct krbd_ctx *ctx,