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>

1 files changed, 8 insertions, 66 deletions

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);
 }