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>

5 files changed, 131 insertions, 115 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index d992880d21d4..47068b10baf8 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -113,58 +113,41 @@ const char *ceph_cap_string(int caps)
         return cap_str[i];
 }
 
-/*
- * 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.
- */
-static spinlock_t caps_list_lock;
-static struct list_head caps_list;  /* unused (reserved or unreserved) */
-static int caps_total_count;        /* total caps allocated */
-static int caps_use_count;          /* in use */
-static int caps_reserve_count;      /* unused, reserved */
-static int caps_avail_count;        /* unused, unreserved */
-static int caps_min_count;          /* keep at least this many (unreserved) */
-
-void __init ceph_caps_init(void)
+void ceph_caps_init(struct ceph_mds_client *mdsc)
 {
-        INIT_LIST_HEAD(&caps_list);
-        spin_lock_init(&caps_list_lock);
+        INIT_LIST_HEAD(&mdsc->caps_list);
+        spin_lock_init(&mdsc->caps_list_lock);
 }
 
-void ceph_caps_finalize(void)
+void ceph_caps_finalize(struct ceph_mds_client *mdsc)
 {
         struct ceph_cap *cap;
 
-        spin_lock(&caps_list_lock);
-        while (!list_empty(&caps_list)) {
-                cap = list_first_entry(&caps_list, struct ceph_cap, caps_item);
+        spin_lock(&mdsc->caps_list_lock);
+        while (!list_empty(&mdsc->caps_list)) {
+                cap = list_first_entry(&mdsc->caps_list,
+                                       struct ceph_cap, caps_item);
                 list_del(&cap->caps_item);
                 kmem_cache_free(ceph_cap_cachep, cap);
         }
-        caps_total_count = 0;
-        caps_avail_count = 0;
-        caps_use_count = 0;
-        caps_reserve_count = 0;
-        caps_min_count = 0;
-        spin_unlock(&caps_list_lock);
+        mdsc->caps_total_count = 0;
+        mdsc->caps_avail_count = 0;
+        mdsc->caps_use_count = 0;
+        mdsc->caps_reserve_count = 0;
+        mdsc->caps_min_count = 0;
+        spin_unlock(&mdsc->caps_list_lock);
 }
 
-void ceph_adjust_min_caps(int delta)
+void ceph_adjust_min_caps(struct ceph_mds_client *mdsc, int delta)
 {
-        spin_lock(&caps_list_lock);
-        caps_min_count += delta;
-        BUG_ON(caps_min_count < 0);
-        spin_unlock(&caps_list_lock);
+        spin_lock(&mdsc->caps_list_lock);
+        mdsc->caps_min_count += delta;
+        BUG_ON(mdsc->caps_min_count < 0);
+        spin_unlock(&mdsc->caps_list_lock);
 }
 
-int ceph_reserve_caps(struct ceph_cap_reservation *ctx, int need)
+int ceph_reserve_caps(struct ceph_mds_client *mdsc,
+                      struct ceph_cap_reservation *ctx, int need)
 {
         int i;
         struct ceph_cap *cap;
@@ -176,16 +159,17 @@ int ceph_reserve_caps(struct ceph_cap_reservation *ctx, int need)
         dout("reserve caps ctx=%p need=%d\n", ctx, need);
 
         /* first reserve any caps that are already allocated */
-        spin_lock(&caps_list_lock);
-        if (caps_avail_count >= need)
+        spin_lock(&mdsc->caps_list_lock);
+        if (mdsc->caps_avail_count >= need)
                 have = need;
         else
-                have = caps_avail_count;
-        caps_avail_count -= have;
-        caps_reserve_count += have;
-        BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
-               caps_avail_count);
-        spin_unlock(&caps_list_lock);
+                have = mdsc->caps_avail_count;
+        mdsc->caps_avail_count -= have;
+        mdsc->caps_reserve_count += have;
+        BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
+                                         mdsc->caps_reserve_count +
+                                         mdsc->caps_avail_count);
+        spin_unlock(&mdsc->caps_list_lock);
 
         for (i = have; i < need; i++) {
                 cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
@@ -198,19 +182,20 @@ int ceph_reserve_caps(struct ceph_cap_reservation *ctx, int need)
         }
         BUG_ON(have + alloc != need);
 
-        spin_lock(&caps_list_lock);
-        caps_total_count += alloc;
-        caps_reserve_count += alloc;
-        list_splice(&newcaps, &caps_list);
+        spin_lock(&mdsc->caps_list_lock);
+        mdsc->caps_total_count += alloc;
+        mdsc->caps_reserve_count += alloc;
+        list_splice(&newcaps, &mdsc->caps_list);
 
-        BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
-               caps_avail_count);
-        spin_unlock(&caps_list_lock);
+        BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
+                                         mdsc->caps_reserve_count +
+                                         mdsc->caps_avail_count);
+        spin_unlock(&mdsc->caps_list_lock);
 
         ctx->count = need;
         dout("reserve caps ctx=%p %d = %d used + %d resv + %d avail\n",
-             ctx, caps_total_count, caps_use_count, caps_reserve_count,
-             caps_avail_count);
+             ctx, mdsc->caps_total_count, mdsc->caps_use_count,
+             mdsc->caps_reserve_count, mdsc->caps_avail_count);
         return 0;
 
 out_alloc_count:
@@ -220,26 +205,29 @@ out_alloc_count:
         return ret;
 }
 
-int ceph_unreserve_caps(struct ceph_cap_reservation *ctx)
+int ceph_unreserve_caps(struct ceph_mds_client *mdsc,
+                        struct ceph_cap_reservation *ctx)
 {
         dout("unreserve caps ctx=%p count=%d\n", ctx, ctx->count);
         if (ctx->count) {
-                spin_lock(&caps_list_lock);
-                BUG_ON(caps_reserve_count < ctx->count);
-                caps_reserve_count -= ctx->count;
-                caps_avail_count += ctx->count;
+                spin_lock(&mdsc->caps_list_lock);
+                BUG_ON(mdsc->caps_reserve_count < ctx->count);
+                mdsc->caps_reserve_count -= ctx->count;
+                mdsc->caps_avail_count += ctx->count;
                 ctx->count = 0;
                 dout("unreserve caps %d = %d used + %d resv + %d avail\n",
-                     caps_total_count, caps_use_count, caps_reserve_count,
-                     caps_avail_count);
-                BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
-                       caps_avail_count);
-                spin_unlock(&caps_list_lock);
+                     mdsc->caps_total_count, mdsc->caps_use_count,
+                     mdsc->caps_reserve_count, mdsc->caps_avail_count);
+                BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
+                                                 mdsc->caps_reserve_count +
+                                                 mdsc->caps_avail_count);
+                spin_unlock(&mdsc->caps_list_lock);
         }
         return 0;
 }
 
-static struct ceph_cap *get_cap(struct ceph_cap_reservation *ctx)
+static struct ceph_cap *get_cap(struct ceph_mds_client *mdsc,
+                                struct ceph_cap_reservation *ctx)
 {
         struct ceph_cap *cap = NULL;
 
@@ -247,71 +235,74 @@ static struct ceph_cap *get_cap(struct ceph_cap_reservation *ctx)
         if (!ctx) {
                 cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
                 if (cap) {
-                        caps_use_count++;
-                        caps_total_count++;
+                        mdsc->caps_use_count++;
+                        mdsc->caps_total_count++;
                 }
                 return cap;
         }
 
-        spin_lock(&caps_list_lock);
+        spin_lock(&mdsc->caps_list_lock);
         dout("get_cap ctx=%p (%d) %d = %d used + %d resv + %d avail\n",
-             ctx, ctx->count, caps_total_count, caps_use_count,
-             caps_reserve_count, caps_avail_count);
+             ctx, ctx->count, mdsc->caps_total_count, mdsc->caps_use_count,
+             mdsc->caps_reserve_count, mdsc->caps_avail_count);
         BUG_ON(!ctx->count);
-        BUG_ON(ctx->count > caps_reserve_count);
-        BUG_ON(list_empty(&caps_list));
+        BUG_ON(ctx->count > mdsc->caps_reserve_count);
+        BUG_ON(list_empty(&mdsc->caps_list));
 
         ctx->count--;
-        caps_reserve_count--;
-        caps_use_count++;
+        mdsc->caps_reserve_count--;
+        mdsc->caps_use_count++;
 
-        cap = list_first_entry(&caps_list, struct ceph_cap, caps_item);
+        cap = list_first_entry(&mdsc->caps_list, struct ceph_cap, caps_item);
         list_del(&cap->caps_item);
 
-        BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
-               caps_avail_count);
-        spin_unlock(&caps_list_lock);
+        BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
+               mdsc->caps_reserve_count + mdsc->caps_avail_count);
+        spin_unlock(&mdsc->caps_list_lock);
         return cap;
 }
 
-void ceph_put_cap(struct ceph_cap *cap)
+void ceph_put_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap)
 {
-        spin_lock(&caps_list_lock);
+        spin_lock(&mdsc->caps_list_lock);
         dout("put_cap %p %d = %d used + %d resv + %d avail\n",
-             cap, caps_total_count, caps_use_count,
-             caps_reserve_count, caps_avail_count);
-        caps_use_count--;
+             cap, mdsc->caps_total_count, mdsc->caps_use_count,
+             mdsc->caps_reserve_count, mdsc->caps_avail_count);
+        mdsc->caps_use_count--;
         /*
          * Keep some preallocated caps around (ceph_min_count), to
          * avoid lots of free/alloc churn.
          */
-        if (caps_avail_count >= caps_reserve_count + caps_min_count) {
-                caps_total_count--;
+        if (mdsc->caps_avail_count >= mdsc->caps_reserve_count +
+                                      mdsc->caps_min_count) {
+                mdsc->caps_total_count--;
                 kmem_cache_free(ceph_cap_cachep, cap);
         } else {
-                caps_avail_count++;
-                list_add(&cap->caps_item, &caps_list);
+                mdsc->caps_avail_count++;
+                list_add(&cap->caps_item, &mdsc->caps_list);
         }
 
-        BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
-               caps_avail_count);
-        spin_unlock(&caps_list_lock);
+        BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
+               mdsc->caps_reserve_count + mdsc->caps_avail_count);
+        spin_unlock(&mdsc->caps_list_lock);
 }
 
 void ceph_reservation_status(struct ceph_client *client,
                              int *total, int *avail, int *used, int *reserved,
                              int *min)
 {
+        struct ceph_mds_client *mdsc = &client->mdsc;
+
         if (total)
-                *total = caps_total_count;
+                *total = mdsc->caps_total_count;
         if (avail)
-                *avail = caps_avail_count;
+                *avail = mdsc->caps_avail_count;
         if (used)
-                *used = caps_use_count;
+                *used = mdsc->caps_use_count;
         if (reserved)
-                *reserved = caps_reserve_count;
+                *reserved = mdsc->caps_reserve_count;
         if (min)
-                *min = caps_min_count;
+                *min = mdsc->caps_min_count;
 }
 
 /*
@@ -540,7 +531,7 @@ retry:
                         new_cap = NULL;
                 } else {
                         spin_unlock(&inode->i_lock);
-                        new_cap = get_cap(caps_reservation);
+                        new_cap = get_cap(mdsc, caps_reservation);
                         if (new_cap == NULL)
                                 return -ENOMEM;
                         goto retry;
@@ -898,7 +889,7 @@ void __ceph_remove_cap(struct ceph_cap *cap)
                 ci->i_auth_cap = NULL;
 
         if (removed)
-                ceph_put_cap(cap);
+                ceph_put_cap(mdsc, cap);
 
         if (!__ceph_is_any_caps(ci) && ci->i_snap_realm) {
                 struct ceph_snap_realm *realm = ci->i_snap_realm;
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 6e40db2a0014..641a8a37e7b3 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -449,7 +449,7 @@ void ceph_mdsc_release_request(struct kref *kref)
         kfree(req->r_path1);
         kfree(req->r_path2);
         put_request_session(req);
-        ceph_unreserve_caps(&req->r_caps_reservation);
+        ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
         kfree(req);
 }
 
@@ -512,7 +512,8 @@ static void __register_request(struct ceph_mds_client *mdsc,
 {
         req->r_tid = ++mdsc->last_tid;
         if (req->r_num_caps)
-                ceph_reserve_caps(&req->r_caps_reservation, req->r_num_caps);
+                ceph_reserve_caps(mdsc, &req->r_caps_reservation,
+                                  req->r_num_caps);
         dout("__register_request %p tid %lld\n", req, req->r_tid);
         ceph_mdsc_get_request(req);
         __insert_request(mdsc, req);
@@ -764,7 +765,7 @@ static int iterate_session_caps(struct ceph_mds_session *session,
                         last_inode = NULL;
                 }
                 if (old_cap) {
-                        ceph_put_cap(old_cap);
+                        ceph_put_cap(session->s_mdsc, old_cap);
                         old_cap = NULL;
                 }
 
@@ -793,7 +794,7 @@ out:
         if (last_inode)
                 iput(last_inode);
         if (old_cap)
-                ceph_put_cap(old_cap);
+                ceph_put_cap(session->s_mdsc, old_cap);
 
         return ret;
 }
@@ -1251,6 +1252,7 @@ ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
                 return ERR_PTR(-ENOMEM);
 
         mutex_init(&req->r_fill_mutex);
+        req->r_mdsc = mdsc;
         req->r_started = jiffies;
         req->r_resend_mds = -1;
         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
@@ -1986,7 +1988,7 @@ static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
         if (err == 0) {
                 if (result == 0 && rinfo->dir_nr)
                         ceph_readdir_prepopulate(req, req->r_session);
-                ceph_unreserve_caps(&req->r_caps_reservation);
+                ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
         }
         mutex_unlock(&req->r_fill_mutex);
 
@@ -2767,6 +2769,9 @@ int ceph_mdsc_init(struct ceph_mds_client *mdsc, struct ceph_client *client)
         spin_lock_init(&mdsc->dentry_lru_lock);
         INIT_LIST_HEAD(&mdsc->dentry_lru);
 
+        ceph_caps_init(mdsc);
+        ceph_adjust_min_caps(mdsc, client->min_caps);
+
         return 0;
 }
 
@@ -2962,6 +2967,7 @@ void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
         if (mdsc->mdsmap)
                 ceph_mdsmap_destroy(mdsc->mdsmap);
         kfree(mdsc->sessions);
+        ceph_caps_finalize(mdsc);
 }
 
 
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
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index fa87f51e38e1..1a0bb4863a5d 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -630,7 +630,6 @@ static struct ceph_client *ceph_create_client(struct ceph_mount_args *args)
 
         /* caps */
         client->min_caps = args->max_readdir;
-        ceph_adjust_min_caps(client->min_caps);
 
         /* subsystems */
         err = ceph_monc_init(&client->monc, client);
@@ -680,8 +679,6 @@ static void ceph_destroy_client(struct ceph_client *client)
 
         ceph_monc_stop(&client->monc);
 
-        ceph_adjust_min_caps(-client->min_caps);
-
         ceph_debugfs_client_cleanup(client);
         destroy_workqueue(client->wb_wq);
         destroy_workqueue(client->pg_inv_wq);
@@ -1043,8 +1040,6 @@ static int __init init_ceph(void)
         if (ret)
                 goto out_msgr;
 
-        ceph_caps_init();
-
         ret = register_filesystem(&ceph_fs_type);
         if (ret)
                 goto out_icache;
@@ -1069,7 +1064,6 @@ static void __exit exit_ceph(void)
 {
         dout("exit_ceph\n");
         unregister_filesystem(&ceph_fs_type);
-        ceph_caps_finalize();
         destroy_caches();
         ceph_msgr_exit();
         ceph_debugfs_cleanup();
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 10a4a406e887..44d10cb0aeca 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -560,11 +560,13 @@ static inline int __ceph_caps_wanted(struct ceph_inode_info *ci)
 /* what the mds thinks we want */
 extern int __ceph_caps_mds_wanted(struct ceph_inode_info *ci);
 
-extern void ceph_caps_init(void);
-extern void ceph_caps_finalize(void);
-extern void ceph_adjust_min_caps(int delta);
-extern int ceph_reserve_caps(struct ceph_cap_reservation *ctx, int need);
-extern int ceph_unreserve_caps(struct ceph_cap_reservation *ctx);
+extern void ceph_caps_init(struct ceph_mds_client *mdsc);
+extern void ceph_caps_finalize(struct ceph_mds_client *mdsc);
+extern void ceph_adjust_min_caps(struct ceph_mds_client *mdsc, int delta);
+extern int ceph_reserve_caps(struct ceph_mds_client *mdsc,
+                             struct ceph_cap_reservation *ctx, int need);
+extern int ceph_unreserve_caps(struct ceph_mds_client *mdsc,
+                               struct ceph_cap_reservation *ctx);
 extern void ceph_reservation_status(struct ceph_client *client,
                                     int *total, int *avail, int *used,
                                     int *reserved, int *min);
@@ -806,7 +808,8 @@ static inline void ceph_remove_cap(struct ceph_cap *cap)
         __ceph_remove_cap(cap);
         spin_unlock(&inode->i_lock);
 }
-extern void ceph_put_cap(struct ceph_cap *cap);
+extern void ceph_put_cap(struct ceph_mds_client *mdsc,
+                         struct ceph_cap *cap);
 
 extern void ceph_queue_caps_release(struct inode *inode);
 extern int ceph_write_inode(struct inode *inode, struct writeback_control *wbc);