IB/core: Rename write flag to exclusive in rdma_core

We rename the "write" flags to "exclusive", as it's used for both
WRITE and DESTROY actions.

Fixes: 3832125624b7 ('IB/core: Add support for idr types')
Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c
index e5bdf7f675744dd9019347517153e5eda24fb745..88d1e596f910ff764d06b43fac66090a89da71fc 100644 (file)
--- a/drivers/infiniband/core/rdma_core.c
+++ b/drivers/infiniband/core/rdma_core.c
@@ -44,7 +44,7 @@ void uverbs_uobject_get(struct ib_uobject *uobject)
        kref_get(&uobject->ref);
 }
 
-static void uverbs_uobject_put_ref(struct kref *ref)
+static void uverbs_uobject_free(struct kref *ref)
 {
        struct ib_uobject *uobj =
                container_of(ref, struct ib_uobject, ref);
@@ -57,21 +57,23 @@ static void uverbs_uobject_put_ref(struct kref *ref)
 
 void uverbs_uobject_put(struct ib_uobject *uobject)
 {
-       kref_put(&uobject->ref, uverbs_uobject_put_ref);
+       kref_put(&uobject->ref, uverbs_uobject_free);
 }
 
-static int uverbs_try_lock_object(struct ib_uobject *uobj, bool write)
+static int uverbs_try_lock_object(struct ib_uobject *uobj, bool exclusive)
 {
        /*
-        * When a read is required, we use a positive counter. Each read
-        * request checks that the value != -1 and increment it. Write
-        * requires an exclusive access, thus we check that the counter is
-        * zero (nobody claimed this object) and we set it to -1.
-        * Releasing a read lock is done by simply decreasing the counter.
-        * As for writes, since only a single write is permitted, setting
-        * it to zero is enough for releasing it.
+        * When a shared access is required, we use a positive counter. Each
+        * shared access request checks that the value != -1 and increment it.
+        * Exclusive access is required for operations like write or destroy.
+        * In exclusive access mode, we check that the counter is zero (nobody
+        * claimed this object) and we set it to -1. Releasing a shared access
+        * lock is done simply by decreasing the counter. As for exclusive
+        * access locks, since only a single one of them is is allowed
+        * concurrently, setting the counter to zero is enough for releasing
+        * this lock.
         */
-       if (!write)
+       if (!exclusive)
                return __atomic_add_unless(&uobj->usecnt, 1, -1) == -1 ?
                        -EBUSY : 0;
 
@@ -135,7 +137,7 @@ static void uverbs_idr_remove_uobj(struct ib_uobject *uobj)
 /* Returns the ib_uobject or an error. The caller should check for IS_ERR. */
 static struct ib_uobject *lookup_get_idr_uobject(const struct uverbs_obj_type *type,
                                                 struct ib_ucontext *ucontext,
-                                                int id, bool write)
+                                                int id, bool exclusive)
 {
        struct ib_uobject *uobj;
 
@@ -155,14 +157,14 @@ free:
 
 static struct ib_uobject *lookup_get_fd_uobject(const struct uverbs_obj_type *type,
                                                struct ib_ucontext *ucontext,
-                                               int id, bool write)
+                                               int id, bool exclusive)
 {
        struct file *f;
        struct ib_uobject *uobject;
        const struct uverbs_obj_fd_type *fd_type =
                container_of(type, struct uverbs_obj_fd_type, type);
 
-       if (write)
+       if (exclusive)
                return ERR_PTR(-EOPNOTSUPP);
 
        f = fget(id);
@@ -186,12 +188,12 @@ static struct ib_uobject *lookup_get_fd_uobject(const struct uverbs_obj_type *ty
 
 struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_obj_type *type,
                                           struct ib_ucontext *ucontext,
-                                          int id, bool write)
+                                          int id, bool exclusive)
 {
        struct ib_uobject *uobj;
        int ret;
 
-       uobj = type->type_class->lookup_get(type, ucontext, id, write);
+       uobj = type->type_class->lookup_get(type, ucontext, id, exclusive);
        if (IS_ERR(uobj))
                return uobj;
 
@@ -200,7 +202,7 @@ struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_obj_type *type,
                goto free;
        }
 
-       ret = uverbs_try_lock_object(uobj, write);
+       ret = uverbs_try_lock_object(uobj, exclusive);
        if (ret) {
                WARN(ucontext->cleanup_reason,
                     "ib_uverbs: Trying to lookup_get while cleanup context\n");
@@ -209,7 +211,7 @@ struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_obj_type *type,
 
        return uobj;
 free:
-       uobj->type->type_class->lookup_put(uobj, write);
+       uobj->type->type_class->lookup_put(uobj, exclusive);
        uverbs_uobject_put(uobj);
        return ERR_PTR(ret);
 }
@@ -350,10 +352,10 @@ static int __must_check remove_commit_fd_uobject(struct ib_uobject *uobj,
        return ret;
 }
 
-static void lockdep_check(struct ib_uobject *uobj, bool write)
+static void lockdep_check(struct ib_uobject *uobj, bool exclusive)
 {
 #ifdef CONFIG_LOCKDEP
-       if (write)
+       if (exclusive)
                WARN_ON(atomic_read(&uobj->usecnt) > 0);
        else
                WARN_ON(atomic_read(&uobj->usecnt) == -1);
@@ -465,29 +467,29 @@ void rdma_alloc_abort_uobject(struct ib_uobject *uobj)
        uobj->type->type_class->alloc_abort(uobj);
 }
 
-static void lookup_put_idr_uobject(struct ib_uobject *uobj, bool write)
+static void lookup_put_idr_uobject(struct ib_uobject *uobj, bool exclusive)
 {
 }
 
-static void lookup_put_fd_uobject(struct ib_uobject *uobj, bool write)
+static void lookup_put_fd_uobject(struct ib_uobject *uobj, bool exclusive)
 {
        struct file *filp = uobj->object;
 
-       WARN_ON(write);
+       WARN_ON(exclusive);
        /* This indirectly calls uverbs_close_fd and free the object */
        fput(filp);
 }
 
-void rdma_lookup_put_uobject(struct ib_uobject *uobj, bool write)
+void rdma_lookup_put_uobject(struct ib_uobject *uobj, bool exclusive)
 {
-       lockdep_check(uobj, write);
-       uobj->type->type_class->lookup_put(uobj, write);
+       lockdep_check(uobj, exclusive);
+       uobj->type->type_class->lookup_put(uobj, exclusive);
        /*
         * In order to unlock an object, either decrease its usecnt for
-        * read access or zero it in case of write access. See
+        * read access or zero it in case of exclusive access. See
         * uverbs_try_lock_object for locking schema information.
         */
-       if (!write)
+       if (!exclusive)
                atomic_dec(&uobj->usecnt);
        else
                atomic_set(&uobj->usecnt, 0);
@@ -512,7 +514,7 @@ const struct uverbs_obj_type_class uverbs_idr_class = {
         * When the other thread continue - without the RCU, it would
         * access freed memory. However, the rcu_read_lock delays the free
         * until the rcu_read_lock of the READ operation quits. Since the
-        * write lock of the object is still taken by the DESTROY flow, the
+        * exclusive lock of the object is still taken by the DESTROY flow, the
         * READ operation will get -EBUSY and it'll just bail out.
         */
        .needs_kfree_rcu = true,

diff --git a/include/rdma/uverbs_types.h b/include/rdma/uverbs_types.h
index a37692167a45d2a49810ffcd263ec98266b49501..351ea185df44fee1af734ae6cad770f1a5ba6c6d 100644 (file)
--- a/include/rdma/uverbs_types.h
+++ b/include/rdma/uverbs_types.h
@@ -54,17 +54,18 @@ struct uverbs_obj_type_class {
         *               destroyed.
         * [lookup]:     Starts with lookup_get which fetches and locks the
         *               object. After the handler finished using the object, it
-        *               needs to call lookup_put to unlock it. The write flag
-        *               indicates if the object is locked for exclusive access.
-        * [remove]:     Starts with lookup_get with write flag set. This locks
-        *               the object for exclusive access. If the handler code
-        *               completed successfully, remove_commit is called and
-        *               the ib_uobject is removed from the context's uobjects
-        *               repository and put. The object itself is destroyed as
-        *               well. Once remove succeeds new krefs to the object
-        *               cannot be acquired by other threads or userspace and
-        *               the hardware driver is removed from the object.
-        *               Other krefs on the object may still exist.
+        *               needs to call lookup_put to unlock it. The exclusive
+        *               flag indicates if the object is locked for exclusive
+        *               access.
+        * [remove]:     Starts with lookup_get with exclusive flag set. This
+        *               locks the object for exclusive access. If the handler
+        *               code completed successfully, remove_commit is called
+        *               and the ib_uobject is removed from the context's
+        *               uobjects repository and put. The object itself is
+        *               destroyed as well. Once remove succeeds new krefs to
+        *               the object cannot be acquired by other threads or
+        *               userspace and the hardware driver is removed from the
+        *               object. Other krefs on the object may still exist.
         *               If the handler code failed, lookup_put should be
         *               called. This callback is used when the context
         *               is destroyed as well (process termination,
@@ -77,10 +78,10 @@ struct uverbs_obj_type_class {
 
        struct ib_uobject *(*lookup_get)(const struct uverbs_obj_type *type,
                                         struct ib_ucontext *ucontext, int id,
-                                        bool write);
-       void (*lookup_put)(struct ib_uobject *uobj, bool write);
+                                        bool exclusive);
+       void (*lookup_put)(struct ib_uobject *uobj, bool exclusive);
        /*
-        * Must be called with the write lock held. If successful uobj is
+        * Must be called with the exclusive lock held. If successful uobj is
         * invalid on return. On failure uobject is left completely
         * unchanged
         */
@@ -121,8 +122,8 @@ struct uverbs_obj_idr_type {
 
 struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_obj_type *type,
                                           struct ib_ucontext *ucontext,
-                                          int id, bool write);
-void rdma_lookup_put_uobject(struct ib_uobject *uobj, bool write);
+                                          int id, bool exclusive);
+void rdma_lookup_put_uobject(struct ib_uobject *uobj, bool exclusive);
 struct ib_uobject *rdma_alloc_begin_uobject(const struct uverbs_obj_type *type,
                                            struct ib_ucontext *ucontext);
 void rdma_alloc_abort_uobject(struct ib_uobject *uobj);