From b9b0f34531e0f8ff7fd0b78adfbc0e8209900f83 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Wed, 20 Feb 2019 16:20:45 -0800 Subject: [PATCH] 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: Matthew Wilcox Signed-off-by: Jason Gunthorpe --- drivers/infiniband/core/rdma_core.c | 76 +++++++++-------------------- drivers/infiniband/core/uverbs.h | 4 +- 2 files changed, 25 insertions(+), 55 deletions(-) diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c index e9c905220abd..ccf4d069c25c 100644 --- a/drivers/infiniband/core/rdma_core.c +++ b/drivers/infiniband/core/rdma_core.c @@ -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; + /* + * 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. + */ + 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 = { diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h index d2c29868172c..1e5aeb39f774 100644 --- a/drivers/infiniband/core/uverbs.h +++ b/drivers/infiniband/core/uverbs.h @@ -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 {