NFSv4: Replace lock_owner->ld_id with an ida based allocator

Again, We're unlikely to ever need more than 2^31 simultaneous lock
owners, so let's replace the custom allocator.

Now that there are no more users, we can also get rid of the custom
allocator code.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

5 files changed, 15 insertions, 76 deletions

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 8d1739d3424d..df60d9971b95 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1093,6 +1093,7 @@ static struct nfs_server *nfs_alloc_server(void)
         }
 
         ida_init(&server->openowner_id);
+        ida_init(&server->lockowner_id);
         pnfs_init_server(server);
 
         return server;
@@ -1118,6 +1119,7 @@ void nfs_free_server(struct nfs_server *server)
 
         nfs_put_client(server->nfs_client);
 
+        ida_destroy(&server->lockowner_id);
         ida_destroy(&server->openowner_id);
         nfs_free_iostats(server->io_stats);
         bdi_destroy(&server->backing_dev_info);
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 091b679747ed..b23cb0cda632 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -81,11 +81,6 @@ static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status
                 seqid->flags |= NFS_SEQID_CONFIRMED;
 }
 
-struct nfs_unique_id {
-        struct rb_node rb_node;
-        __u64 id;
-};
-
 /*
  * NFS4 state_owners and lock_owners are simply labels for ordered
  * sequences of RPC calls. Their sole purpose is to provide once-only
@@ -145,9 +140,9 @@ struct nfs4_lock_state {
         struct nfs4_state *     ls_state;       /* Pointer to open state */
 #define NFS_LOCK_INITIALIZED 1
         int                     ls_flags;
+        int                     ls_id;
         struct nfs_seqid_counter        ls_seqid;
         struct rpc_sequence     ls_sequence;
-        struct nfs_unique_id    ls_id;
         nfs4_stateid            ls_stateid;
         atomic_t                ls_count;
         struct nfs4_lock_owner  ls_owner;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 1dd2e407a901..9c77af900960 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4017,7 +4017,7 @@ static int _nfs4_proc_getlk(struct nfs4_state *state, int cmd, struct file_lock
         if (status != 0)
                 goto out;
         lsp = request->fl_u.nfs4_fl.owner;
-        arg.lock_owner.id = lsp->ls_id.id;
+        arg.lock_owner.id = lsp->ls_id;
         arg.lock_owner.s_dev = server->s_dev;
         status = nfs4_call_sync(server->client, server, &msg, &arg.seq_args, &res.seq_res, 1);
         switch (status) {
@@ -4262,7 +4262,7 @@ static struct nfs4_lockdata *nfs4_alloc_lockdata(struct file_lock *fl,
                 goto out_free_seqid;
         p->arg.lock_stateid = &lsp->ls_stateid;
         p->arg.lock_owner.clientid = server->nfs_client->cl_clientid;
-        p->arg.lock_owner.id = lsp->ls_id.id;
+        p->arg.lock_owner.id = lsp->ls_id;
         p->arg.lock_owner.s_dev = server->s_dev;
         p->res.lock_seqid = p->arg.lock_seqid;
         p->lsp = lsp;
@@ -4679,7 +4679,7 @@ void nfs4_release_lockowner(const struct nfs4_lock_state *lsp)
         if (!args)
                 return;
         args->lock_owner.clientid = server->nfs_client->cl_clientid;
-        args->lock_owner.id = lsp->ls_id.id;
+        args->lock_owner.id = lsp->ls_id;
         args->lock_owner.s_dev = server->s_dev;
         msg.rpc_argp = args;
         rpc_call_async(server->client, &msg, 0, &nfs4_release_lockowner_ops, args);
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 8472707286f9..5abf23615bc5 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -317,62 +317,6 @@ out:
         return cred;
 }
 
-static void nfs_alloc_unique_id_locked(struct rb_root *root,
-                                       struct nfs_unique_id *new,
-                                       __u64 minval, int maxbits)
-{
-        struct rb_node **p, *parent;
-        struct nfs_unique_id *pos;
-        __u64 mask = ~0ULL;
-
-        if (maxbits < 64)
-                mask = (1ULL << maxbits) - 1ULL;
-
-        /* Ensure distribution is more or less flat */
-        get_random_bytes(&new->id, sizeof(new->id));
-        new->id &= mask;
-        if (new->id < minval)
-                new->id += minval;
-retry:
-        p = &root->rb_node;
-        parent = NULL;
-
-        while (*p != NULL) {
-                parent = *p;
-                pos = rb_entry(parent, struct nfs_unique_id, rb_node);
-
-                if (new->id < pos->id)
-                        p = &(*p)->rb_left;
-                else if (new->id > pos->id)
-                        p = &(*p)->rb_right;
-                else
-                        goto id_exists;
-        }
-        rb_link_node(&new->rb_node, parent, p);
-        rb_insert_color(&new->rb_node, root);
-        return;
-id_exists:
-        for (;;) {
-                new->id++;
-                if (new->id < minval || (new->id & mask) != new->id) {
-                        new->id = minval;
-                        break;
-                }
-                parent = rb_next(parent);
-                if (parent == NULL)
-                        break;
-                pos = rb_entry(parent, struct nfs_unique_id, rb_node);
-                if (new->id < pos->id)
-                        break;
-        }
-        goto retry;
-}
-
-static void nfs_free_unique_id(struct rb_root *root, struct nfs_unique_id *id)
-{
-        rb_erase(&id->rb_node, root);
-}
-
 static struct nfs4_state_owner *
 nfs4_find_state_owner_locked(struct nfs_server *server, struct rpc_cred *cred)
 {
@@ -800,7 +744,6 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f
 {
         struct nfs4_lock_state *lsp;
         struct nfs_server *server = state->owner->so_server;
-        struct nfs_client *clp = server->nfs_client;
 
         lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
         if (lsp == NULL)
@@ -820,24 +763,23 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f
                 lsp->ls_owner.lo_u.posix_owner = fl_owner;
                 break;
         default:
-                kfree(lsp);
-                return NULL;
+                goto out_free;
         }
-        spin_lock(&clp->cl_lock);
-        nfs_alloc_unique_id_locked(&server->lockowner_id, &lsp->ls_id, 1, 64);
-        spin_unlock(&clp->cl_lock);
+        lsp->ls_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
+        if (lsp->ls_id < 0)
+                goto out_free;
         INIT_LIST_HEAD(&lsp->ls_locks);
         return lsp;
+out_free:
+        kfree(lsp);
+        return NULL;
 }
 
 static void nfs4_free_lock_state(struct nfs4_lock_state *lsp)
 {
         struct nfs_server *server = lsp->ls_state->owner->so_server;
-        struct nfs_client *clp = server->nfs_client;
 
-        spin_lock(&clp->cl_lock);
-        nfs_free_unique_id(&server->lockowner_id, &lsp->ls_id);
-        spin_unlock(&clp->cl_lock);
+        ida_simple_remove(&server->lockowner_id, lsp->ls_id);
         rpc_destroy_wait_queue(&lsp->ls_sequence.wait);
         kfree(lsp);
 }
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 645537e18bd0..c23469308b8e 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -152,9 +152,9 @@ struct nfs_server {
 
         /* the following fields are protected by nfs_client->cl_lock */
         struct rb_root          state_owners;
-        struct rb_root          lockowner_id;
 #endif
         struct ida              openowner_id;
+        struct ida              lockowner_id;
         struct list_head        state_owners_lru;
         struct list_head        layouts;
         struct list_head        delegations;