Commit b9b0f345 authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Jason Gunthorpe

uverbs: Convert idr to XArray

The word 'idr' is scattered throughout the API, so I haven't changed it,
but the 'idr' variable is now an XArray.
Signed-off-by: default avatarMatthew Wilcox <willy@infradead.org>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent a7b36d5f
......@@ -297,25 +297,13 @@ static struct ib_uobject *alloc_uobj(struct ib_uverbs_file *ufile,
static int idr_add_uobj(struct ib_uobject *uobj)
{
int ret;
idr_preload(GFP_KERNEL);
spin_lock(&uobj->ufile->idr_lock);
/*
* We start with allocating an idr pointing to NULL. This represents an
* object which isn't initialized yet. We'll replace it later on with
* the real object once we commit.
*/
ret = idr_alloc(&uobj->ufile->idr, NULL, 0,
min_t(unsigned long, U32_MAX - 1, INT_MAX), GFP_NOWAIT);
if (ret >= 0)
uobj->id = ret;
spin_unlock(&uobj->ufile->idr_lock);
idr_preload_end();
return ret < 0 ? ret : 0;
return xa_alloc(&uobj->ufile->idr, &uobj->id, NULL, xa_limit_32b,
GFP_KERNEL);
}
/* Returns the ib_uobject or an error. The caller should check for IS_ERR. */
......@@ -325,29 +313,20 @@ lookup_get_idr_uobject(const struct uverbs_api_object *obj,
enum rdma_lookup_mode mode)
{
struct ib_uobject *uobj;
unsigned long idrno = id;
if (id < 0 || id > ULONG_MAX)
return ERR_PTR(-EINVAL);
rcu_read_lock();
/* object won't be released as we're protected in rcu */
uobj = idr_find(&ufile->idr, idrno);
if (!uobj) {
uobj = ERR_PTR(-ENOENT);
goto free;
}
/*
* The idr_find is guaranteed to return a pointer to something that
* isn't freed yet, or NULL, as the free after idr_remove goes through
* kfree_rcu(). However the object may still have been released and
* kfree() could be called at any time.
*/
if (!kref_get_unless_zero(&uobj->ref))
uobj = xa_load(&ufile->idr, id);
if (!uobj || !kref_get_unless_zero(&uobj->ref))
uobj = ERR_PTR(-ENOENT);
free:
rcu_read_unlock();
return uobj;
}
......@@ -400,7 +379,7 @@ struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_api_object *obj,
struct ib_uobject *uobj;
int ret;
if (IS_ERR(obj) && PTR_ERR(obj) == -ENOMSG) {
if (obj == ERR_PTR(-ENOMSG)) {
/* must be UVERBS_IDR_ANY_OBJECT, see uapi_get_object() */
uobj = lookup_get_idr_uobject(NULL, ufile, id, mode);
if (IS_ERR(uobj))
......@@ -461,14 +440,12 @@ alloc_begin_idr_uobject(const struct uverbs_api_object *obj,
ret = ib_rdmacg_try_charge(&uobj->cg_obj, uobj->context->device,
RDMACG_RESOURCE_HCA_OBJECT);
if (ret)
goto idr_remove;
goto remove;
return uobj;
idr_remove:
spin_lock(&ufile->idr_lock);
idr_remove(&ufile->idr, uobj->id);
spin_unlock(&ufile->idr_lock);
remove:
xa_erase(&ufile->idr, uobj->id);
uobj_put:
uverbs_uobject_put(uobj);
return ERR_PTR(ret);
......@@ -529,9 +506,7 @@ static void alloc_abort_idr_uobject(struct ib_uobject *uobj)
ib_rdmacg_uncharge(&uobj->cg_obj, uobj->context->device,
RDMACG_RESOURCE_HCA_OBJECT);
spin_lock(&uobj->ufile->idr_lock);
idr_remove(&uobj->ufile->idr, uobj->id);
spin_unlock(&uobj->ufile->idr_lock);
xa_erase(&uobj->ufile->idr, uobj->id);
}
static int __must_check destroy_hw_idr_uobject(struct ib_uobject *uobj,
......@@ -562,9 +537,7 @@ static int __must_check destroy_hw_idr_uobject(struct ib_uobject *uobj,
static void remove_handle_idr_uobject(struct ib_uobject *uobj)
{
spin_lock(&uobj->ufile->idr_lock);
idr_remove(&uobj->ufile->idr, uobj->id);
spin_unlock(&uobj->ufile->idr_lock);
xa_erase(&uobj->ufile->idr, uobj->id);
/* Matches the kref in alloc_commit_idr_uobject */
uverbs_uobject_put(uobj);
}
......@@ -595,17 +568,17 @@ static void remove_handle_fd_uobject(struct ib_uobject *uobj)
static int alloc_commit_idr_uobject(struct ib_uobject *uobj)
{
struct ib_uverbs_file *ufile = uobj->ufile;
void *old;
spin_lock(&ufile->idr_lock);
/*
* We already allocated this IDR with a NULL object, so
* this shouldn't fail.
*
* NOTE: Once we set the IDR we loose ownership of our kref on uobj.
* NOTE: Storing the uobj transfers our kref on uobj to the XArray.
* It will be put by remove_commit_idr_uobject()
*/
WARN_ON(idr_replace(&ufile->idr, uobj, uobj->id));
spin_unlock(&ufile->idr_lock);
old = xa_store(&ufile->idr, uobj->id, uobj, GFP_KERNEL);
WARN_ON(old != NULL);
return 0;
}
......@@ -739,29 +712,28 @@ void rdma_lookup_put_uobject(struct ib_uobject *uobj,
void setup_ufile_idr_uobject(struct ib_uverbs_file *ufile)
{
spin_lock_init(&ufile->idr_lock);
idr_init(&ufile->idr);
xa_init_flags(&ufile->idr, XA_FLAGS_ALLOC);
}
void release_ufile_idr_uobject(struct ib_uverbs_file *ufile)
{
struct ib_uobject *entry;
int id;
unsigned long id;
/*
* At this point uverbs_cleanup_ufile() is guaranteed to have run, and
* there are no HW objects left, however the IDR is still populated
* there are no HW objects left, however the xarray is still populated
* with anything that has not been cleaned up by userspace. Since the
* kref on ufile is 0, nothing is allowed to call lookup_get.
*
* This is an optimized equivalent to remove_handle_idr_uobject
*/
idr_for_each_entry(&ufile->idr, entry, id) {
xa_for_each(&ufile->idr, id, entry) {
WARN_ON(entry->object);
uverbs_uobject_put(entry);
}
idr_destroy(&ufile->idr);
xa_destroy(&ufile->idr);
}
const struct uverbs_obj_type_class uverbs_idr_class = {
......
......@@ -162,9 +162,7 @@ struct ib_uverbs_file {
struct list_head umaps;
struct page *disassociate_page;
struct idr idr;
/* spinlock protects write access to idr */
spinlock_t idr_lock;
struct xarray idr;
};
struct ib_uverbs_event {
......
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