Commit cf8966b3 authored by Matan Barak's avatar Matan Barak Committed by Doug Ledford

IB/core: Add support for fd objects

The completion channel we use in verbs infrastructure is FD based.
Previously, we had a separate way to manage this object. Since we
strive for a single way to manage any kind of object in this
infrastructure, we conceptually treat all objects as subclasses
of ib_uobject.

This commit adds the necessary mechanism to support FD based objects
like their IDR counterparts. FD objects release need to be synchronized
with context release. We use the cleanup_mutex on the uverbs_file for
that.
Signed-off-by: default avatarMatan Barak <matanb@mellanox.com>
Reviewed-by: default avatarYishai Hadas <yishaih@mellanox.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent f48b7269
......@@ -153,6 +153,37 @@ static struct ib_uobject *lookup_get_idr_uobject(const struct uverbs_obj_type *t
return uobj;
}
static struct ib_uobject *lookup_get_fd_uobject(const struct uverbs_obj_type *type,
struct ib_ucontext *ucontext,
int id, bool write)
{
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)
return ERR_PTR(-EOPNOTSUPP);
f = fget(id);
if (!f)
return ERR_PTR(-EBADF);
uobject = f->private_data;
/*
* fget(id) ensures we are not currently running uverbs_close_fd,
* and the caller is expected to ensure that uverbs_close_fd is never
* done while a call top lookup is possible.
*/
if (f->f_op != fd_type->fops) {
fput(f);
return ERR_PTR(-EBADF);
}
uverbs_uobject_get(uobject);
return uobject;
}
struct ib_uobject *rdma_lookup_get_uobject(const struct uverbs_obj_type *type,
struct ib_ucontext *ucontext,
int id, bool write)
......@@ -211,6 +242,46 @@ static struct ib_uobject *alloc_begin_idr_uobject(const struct uverbs_obj_type *
return ERR_PTR(ret);
}
static struct ib_uobject *alloc_begin_fd_uobject(const struct uverbs_obj_type *type,
struct ib_ucontext *ucontext)
{
const struct uverbs_obj_fd_type *fd_type =
container_of(type, struct uverbs_obj_fd_type, type);
int new_fd;
struct ib_uobject *uobj;
struct ib_uobject_file *uobj_file;
struct file *filp;
new_fd = get_unused_fd_flags(O_CLOEXEC);
if (new_fd < 0)
return ERR_PTR(new_fd);
uobj = alloc_uobj(ucontext, type);
if (IS_ERR(uobj)) {
put_unused_fd(new_fd);
return uobj;
}
uobj_file = container_of(uobj, struct ib_uobject_file, uobj);
filp = anon_inode_getfile(fd_type->name,
fd_type->fops,
uobj_file,
fd_type->flags);
if (IS_ERR(filp)) {
put_unused_fd(new_fd);
uverbs_uobject_put(uobj);
return (void *)filp;
}
uobj_file->uobj.id = new_fd;
uobj_file->uobj.object = filp;
uobj_file->ufile = ucontext->ufile;
INIT_LIST_HEAD(&uobj->list);
kref_get(&uobj_file->ufile->ref);
return uobj;
}
struct ib_uobject *rdma_alloc_begin_uobject(const struct uverbs_obj_type *type,
struct ib_ucontext *ucontext)
{
......@@ -246,6 +317,39 @@ static int __must_check remove_commit_idr_uobject(struct ib_uobject *uobj,
return ret;
}
static void alloc_abort_fd_uobject(struct ib_uobject *uobj)
{
struct ib_uobject_file *uobj_file =
container_of(uobj, struct ib_uobject_file, uobj);
struct file *filp = uobj->object;
int id = uobj_file->uobj.id;
/* Unsuccessful NEW */
fput(filp);
put_unused_fd(id);
}
static int __must_check remove_commit_fd_uobject(struct ib_uobject *uobj,
enum rdma_remove_reason why)
{
const struct uverbs_obj_fd_type *fd_type =
container_of(uobj->type, struct uverbs_obj_fd_type, type);
struct ib_uobject_file *uobj_file =
container_of(uobj, struct ib_uobject_file, uobj);
int ret = fd_type->context_closed(uobj_file, why);
if (why == RDMA_REMOVE_DESTROY && ret)
return ret;
if (why == RDMA_REMOVE_DURING_CLEANUP) {
alloc_abort_fd_uobject(uobj);
return ret;
}
uobj_file->uobj.context = NULL;
return ret;
}
static void lockdep_check(struct ib_uobject *uobj, bool write)
{
#ifdef CONFIG_LOCKDEP
......@@ -314,6 +418,19 @@ static void alloc_commit_idr_uobject(struct ib_uobject *uobj)
spin_unlock(&uobj->context->ufile->idr_lock);
}
static void alloc_commit_fd_uobject(struct ib_uobject *uobj)
{
struct ib_uobject_file *uobj_file =
container_of(uobj, struct ib_uobject_file, uobj);
uverbs_uobject_add(&uobj_file->uobj);
fd_install(uobj_file->uobj.id, uobj->object);
/* This shouldn't be used anymore. Use the file object instead */
uobj_file->uobj.id = 0;
/* Get another reference as we export this to the fops */
uverbs_uobject_get(&uobj_file->uobj);
}
int rdma_alloc_commit_uobject(struct ib_uobject *uobj)
{
/* Cleanup is running. Calling this should have been impossible */
......@@ -352,6 +469,15 @@ static void lookup_put_idr_uobject(struct ib_uobject *uobj, bool write)
{
}
static void lookup_put_fd_uobject(struct ib_uobject *uobj, bool write)
{
struct file *filp = uobj->object;
WARN_ON(write);
/* This indirectly calls uverbs_close_fd and free the object */
fput(filp);
}
void rdma_lookup_put_uobject(struct ib_uobject *uobj, bool write)
{
lockdep_check(uobj, write);
......@@ -392,6 +518,39 @@ const struct uverbs_obj_type_class uverbs_idr_class = {
.needs_kfree_rcu = true,
};
static void _uverbs_close_fd(struct ib_uobject_file *uobj_file)
{
struct ib_ucontext *ucontext;
struct ib_uverbs_file *ufile = uobj_file->ufile;
int ret;
mutex_lock(&uobj_file->ufile->cleanup_mutex);
/* uobject was either already cleaned up or is cleaned up right now anyway */
if (!uobj_file->uobj.context ||
!down_read_trylock(&uobj_file->uobj.context->cleanup_rwsem))
goto unlock;
ucontext = uobj_file->uobj.context;
ret = _rdma_remove_commit_uobject(&uobj_file->uobj, RDMA_REMOVE_CLOSE,
true);
up_read(&ucontext->cleanup_rwsem);
if (ret)
pr_warn("uverbs: unable to clean up uobject file in uverbs_close_fd.\n");
unlock:
mutex_unlock(&ufile->cleanup_mutex);
}
void uverbs_close_fd(struct file *f)
{
struct ib_uobject_file *uobj_file = f->private_data;
struct kref *uverbs_file_ref = &uobj_file->ufile->ref;
_uverbs_close_fd(uobj_file);
uverbs_uobject_put(&uobj_file->uobj);
kref_put(uverbs_file_ref, ib_uverbs_release_file);
}
void uverbs_cleanup_ucontext(struct ib_ucontext *ucontext, bool device_removed)
{
enum rdma_remove_reason reason = device_removed ?
......@@ -412,7 +571,13 @@ void uverbs_cleanup_ucontext(struct ib_ucontext *ucontext, bool device_removed)
/*
* This shouldn't run while executing other commands on this
* context.
* context. Thus, the only thing we should take care of is
* releasing a FD while traversing this list. The FD could be
* closed and released from the _release fop of this FD.
* In order to mitigate this, we add a lock.
* We take and release the lock per order traversal in order
* to let other threads (which might still use the FDs) chance
* to run.
*/
mutex_lock(&ucontext->uobjects_lock);
list_for_each_entry_safe(obj, next_obj, &ucontext->uobjects,
......@@ -448,3 +613,13 @@ void uverbs_initialize_ucontext(struct ib_ucontext *ucontext)
init_rwsem(&ucontext->cleanup_rwsem);
}
const struct uverbs_obj_type_class uverbs_fd_class = {
.alloc_begin = alloc_begin_fd_uobject,
.lookup_get = lookup_get_fd_uobject,
.alloc_commit = alloc_commit_fd_uobject,
.alloc_abort = alloc_abort_fd_uobject,
.lookup_put = lookup_put_fd_uobject,
.remove_commit = remove_commit_fd_uobject,
.needs_kfree_rcu = false,
};
......@@ -67,4 +67,12 @@ void uverbs_uobject_get(struct ib_uobject *uobject);
*/
void uverbs_uobject_put(struct ib_uobject *uobject);
/* Indicate this fd is no longer used by this consumer, but its memory isn't
* necessarily released yet. When the last reference is put, we release the
* memory. After this call is executed, calling uverbs_uobject_get isn't
* allowed.
* This must be called from the release file_operations of the file!
*/
void uverbs_close_fd(struct file *f);
#endif /* RDMA_CORE_H */
......@@ -193,6 +193,7 @@ void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
struct ib_ucq_object *uobj);
void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
struct ib_uevent_object *uobj);
void ib_uverbs_release_file(struct kref *ref);
void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context);
void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr);
......
......@@ -233,7 +233,7 @@ static void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
complete(&dev->comp);
}
static void ib_uverbs_release_file(struct kref *ref)
void ib_uverbs_release_file(struct kref *ref)
{
struct ib_uverbs_file *file =
container_of(ref, struct ib_uverbs_file, ref);
......@@ -1132,7 +1132,9 @@ static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
* (e.g mmput).
*/
ib_dev->disassociate_ucontext(ucontext);
mutex_lock(&file->cleanup_mutex);
ib_uverbs_cleanup_ucontext(file, ucontext, true);
mutex_unlock(&file->cleanup_mutex);
}
mutex_lock(&uverbs_dev->lists_mutex);
......
......@@ -1421,6 +1421,12 @@ struct ib_uobject {
const struct uverbs_obj_type *type;
};
struct ib_uobject_file {
struct ib_uobject uobj;
/* ufile contains the lock between context release and file close */
struct ib_uverbs_file *ufile;
};
struct ib_udata {
const void __user *inbuf;
void __user *outbuf;
......
......@@ -129,6 +129,22 @@ void rdma_alloc_abort_uobject(struct ib_uobject *uobj);
int __must_check rdma_remove_commit_uobject(struct ib_uobject *uobj);
int rdma_alloc_commit_uobject(struct ib_uobject *uobj);
struct uverbs_obj_fd_type {
/*
* In fd based objects, uverbs_obj_type_ops points to generic
* fd operations. In order to specialize the underlying types (e.g.
* completion_channel), we use fops, name and flags for fd creation.
* context_closed is called when the context is closed either when
* the driver is removed or the process terminated.
*/
struct uverbs_obj_type type;
int (*context_closed)(struct ib_uobject_file *uobj_file,
enum rdma_remove_reason why);
const struct file_operations *fops;
const char *name;
int flags;
};
extern const struct uverbs_obj_type_class uverbs_idr_class;
#define UVERBS_BUILD_BUG_ON(cond) (sizeof(char[1 - 2 * !!(cond)]) - \
......
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