ceph: monitor client

The monitor cluster is responsible for managing cluster membership
and state.  The monitor client handles what minimal interaction
the Ceph client has with it: checking for updated versions of the
MDS and OSD maps, getting statfs() information, and unmounting.

Signed-off-by: Sage Weil <sage@newdream.net>

1 files changed, 109 insertions, 0 deletions

diff --git a/fs/ceph/mon_client.h b/fs/ceph/mon_client.h
new file mode 100644
index 000000000000..5258c5693b03
--- /dev/null
+++ b/fs/ceph/mon_client.h
@@ -0,0 +1,109 @@
+#ifndef _FS_CEPH_MON_CLIENT_H
+#define _FS_CEPH_MON_CLIENT_H
+
+#include <linux/completion.h>
+#include <linux/radix-tree.h>
+
+#include "messenger.h"
+#include "msgpool.h"
+
+struct ceph_client;
+struct ceph_mount_args;
+
+/*
+ * The monitor map enumerates the set of all monitors.
+ */
+struct ceph_monmap {
+        struct ceph_fsid fsid;
+        u32 epoch;
+        u32 num_mon;
+        struct ceph_entity_inst mon_inst[0];
+};
+
+struct ceph_mon_client;
+struct ceph_mon_statfs_request;
+
+
+/*
+ * Generic mechanism for resending monitor requests.
+ */
+typedef void (*ceph_monc_request_func_t)(struct ceph_mon_client *monc,
+                                         int newmon);
+
+/* a pending monitor request */
+struct ceph_mon_request {
+        struct ceph_mon_client *monc;
+        struct delayed_work delayed_work;
+        unsigned long delay;
+        ceph_monc_request_func_t do_request;
+};
+
+/*
+ * statfs() is done a bit differently because we need to get data back
+ * to the caller
+ */
+struct ceph_mon_statfs_request {
+        u64 tid;
+        int result;
+        struct ceph_statfs *buf;
+        struct completion completion;
+        unsigned long last_attempt, delay; /* jiffies */
+        struct ceph_msg *request;  /* original request */
+};
+
+struct ceph_mon_client {
+        struct ceph_client *client;
+        struct ceph_monmap *monmap;
+
+        struct mutex mutex;
+        struct delayed_work delayed_work;
+
+        bool hunting;
+        int cur_mon;                       /* last monitor i contacted */
+        unsigned long sub_sent, sub_renew_after;
+        struct ceph_connection *con;
+
+        /* msg pools */
+        struct ceph_msgpool msgpool_mount_ack;
+        struct ceph_msgpool msgpool_subscribe_ack;
+        struct ceph_msgpool msgpool_statfs_reply;
+
+        /* pending statfs requests */
+        struct radix_tree_root statfs_request_tree;
+        int num_statfs_requests;
+        u64 last_tid;
+
+        /* mds/osd map or mount requests */
+        bool want_mount;
+        int want_next_osdmap; /* 1 = want, 2 = want+asked */
+        u32 have_osdmap, have_mdsmap;
+
+        struct dentry *debugfs_file;
+};
+
+extern struct ceph_monmap *ceph_monmap_decode(void *p, void *end);
+extern int ceph_monmap_contains(struct ceph_monmap *m,
+                                struct ceph_entity_addr *addr);
+
+extern int ceph_monc_init(struct ceph_mon_client *monc, struct ceph_client *cl);
+extern void ceph_monc_stop(struct ceph_mon_client *monc);
+
+/*
+ * The model here is to indicate that we need a new map of at least
+ * epoch @want, and also call in when we receive a map.  We will
+ * periodically rerequest the map from the monitor cluster until we
+ * get what we want.
+ */
+extern int ceph_monc_got_mdsmap(struct ceph_mon_client *monc, u32 have);
+extern int ceph_monc_got_osdmap(struct ceph_mon_client *monc, u32 have);
+
+extern void ceph_monc_request_next_osdmap(struct ceph_mon_client *monc);
+
+extern int ceph_monc_request_mount(struct ceph_mon_client *monc);
+
+extern int ceph_monc_do_statfs(struct ceph_mon_client *monc,
+                               struct ceph_statfs *buf);
+
+
+
+#endif