ceph: do caps accounting per mds_client

Caps related accounting is now being done per mds client instead
of just being global. This prepares ground work for a later revision
of the caps preallocated reservation list.

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

1 files changed, 22 insertions, 0 deletions

diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index e389902db131..8f2126321f2d 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -151,6 +151,7 @@ typedef void (*ceph_mds_request_callback_t) (struct ceph_mds_client *mdsc,
 struct ceph_mds_request {
         u64 r_tid;                   /* transaction id */
         struct rb_node r_node;
+        struct ceph_mds_client *r_mdsc;
 
         int r_op;                    /* mds op code */
         int r_mds;
@@ -267,6 +268,27 @@ struct ceph_mds_client {
         spinlock_t        cap_dirty_lock;   /* protects above items */
         wait_queue_head_t cap_flushing_wq;
 
+        /*
+         * Cap reservations
+         *
+         * Maintain a global pool of preallocated struct ceph_caps, referenced
+         * by struct ceph_caps_reservations.  This ensures that we preallocate
+         * memory needed to successfully process an MDS response.  (If an MDS
+         * sends us cap information and we fail to process it, we will have
+         * problems due to the client and MDS being out of sync.)
+         *
+         * Reservations are 'owned' by a ceph_cap_reservation context.
+         */
+        spinlock_t      caps_list_lock;
+        struct          list_head caps_list; /* unused (reserved or
+                                                unreserved) */
+        int             caps_total_count;    /* total caps allocated */
+        int             caps_use_count;      /* in use */
+        int             caps_reserve_count;  /* unused, reserved */
+        int             caps_avail_count;    /* unused, unreserved */
+        int             caps_min_count;      /* keep at least this many
+                                                (unreserved) */
+
 #ifdef CONFIG_DEBUG_FS
         struct dentry     *debugfs_file;
 #endif