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linux-next/include/rdma/restrack.h
Leon Romanovsky 03286030ac RDMA/restrack: Remove ambiguity in resource track clean logic
The restrack clean routine had simple, but powerful WARN_ON check
to see if all resources are cleared prior to releasing device.

The WARN_ON check performed very well, but lack of information
which device caused to resource leak, the object type and origin
made debug to be fun and challenging at the same time.

The fact that all dumps were the same because restrack_clean() is
called in dealloc() didn't help either.

So let's fix spelling error and convert WARN_ON to be more debug
friendly. The dmesg cut below gives example of how the output
will look output for the case fixed in patch [1]

[  438.421372] restrack: ------------[ cut here ]------------
[  438.423448] restrack: BUG: RESTRACK detected leak of resources on mlx5_2
[  438.425600] restrack: Kernel PD object allocated by mlx5_ib is not freed
[  438.427753] restrack: Kernel CQ object allocated by mlx5_ib is not freed
[  438.429660] restrack: ------------[ cut here ]------------

[1] https://patchwork.kernel.org/patch/10298695/

Cc: Michal Kalderon <Michal.Kalderon@cavium.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-03-22 12:42:48 -06:00

178 lines
4.0 KiB
C

/* SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) */
/*
* Copyright (c) 2017-2018 Mellanox Technologies. All rights reserved.
*/
#ifndef _RDMA_RESTRACK_H_
#define _RDMA_RESTRACK_H_
#include <linux/typecheck.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/kref.h>
#include <linux/completion.h>
#include <linux/sched/task.h>
/**
* enum rdma_restrack_type - HW objects to track
*/
enum rdma_restrack_type {
/**
* @RDMA_RESTRACK_PD: Protection domain (PD)
*/
RDMA_RESTRACK_PD,
/**
* @RDMA_RESTRACK_CQ: Completion queue (CQ)
*/
RDMA_RESTRACK_CQ,
/**
* @RDMA_RESTRACK_QP: Queue pair (QP)
*/
RDMA_RESTRACK_QP,
/**
* @RDMA_RESTRACK_CM_ID: Connection Manager ID (CM_ID)
*/
RDMA_RESTRACK_CM_ID,
/**
* @RDMA_RESTRACK_MR: Memory Region (MR)
*/
RDMA_RESTRACK_MR,
/**
* @RDMA_RESTRACK_MAX: Last entry, used for array dclarations
*/
RDMA_RESTRACK_MAX
};
#define RDMA_RESTRACK_HASH_BITS 8
/**
* struct rdma_restrack_root - main resource tracking management
* entity, per-device
*/
struct rdma_restrack_root {
/*
* @rwsem: Read/write lock to protect lists
*/
struct rw_semaphore rwsem;
/**
* @hash: global database for all resources per-device
*/
DECLARE_HASHTABLE(hash, RDMA_RESTRACK_HASH_BITS);
};
/**
* struct rdma_restrack_entry - metadata per-entry
*/
struct rdma_restrack_entry {
/**
* @valid: validity indicator
*
* The entries are filled during rdma_restrack_add,
* can be attempted to be free during rdma_restrack_del.
*
* As an example for that, see mlx5 QPs with type MLX5_IB_QPT_HW_GSI
*/
bool valid;
/*
* @kref: Protect destroy of the resource
*/
struct kref kref;
/*
* @comp: Signal that all consumers of resource are completed their work
*/
struct completion comp;
/**
* @task: owner of resource tracking entity
*
* There are two types of entities: created by user and created
* by kernel.
*
* This is relevant for the entities created by users.
* For the entities created by kernel, this pointer will be NULL.
*/
struct task_struct *task;
/**
* @kern_name: name of owner for the kernel created entities.
*/
const char *kern_name;
/**
* @node: hash table entry
*/
struct hlist_node node;
/**
* @type: various objects in restrack database
*/
enum rdma_restrack_type type;
};
/**
* rdma_restrack_init() - initialize resource tracking
* @res: resource tracking root
*/
void rdma_restrack_init(struct rdma_restrack_root *res);
/**
* rdma_restrack_clean() - clean resource tracking
* @res: resource tracking root
*/
void rdma_restrack_clean(struct rdma_restrack_root *res);
/**
* rdma_restrack_count() - the current usage of specific object
* @res: resource entry
* @type: actual type of object to operate
* @ns: PID namespace
*/
int rdma_restrack_count(struct rdma_restrack_root *res,
enum rdma_restrack_type type,
struct pid_namespace *ns);
/**
* rdma_restrack_add() - add object to the reource tracking database
* @res: resource entry
*/
void rdma_restrack_add(struct rdma_restrack_entry *res);
/**
* rdma_restrack_del() - delete object from the reource tracking database
* @res: resource entry
* @type: actual type of object to operate
*/
void rdma_restrack_del(struct rdma_restrack_entry *res);
/**
* rdma_is_kernel_res() - check the owner of resource
* @res: resource entry
*/
static inline bool rdma_is_kernel_res(struct rdma_restrack_entry *res)
{
return !res->task;
}
/**
* rdma_restrack_get() - grab to protect resource from release
* @res: resource entry
*/
int __must_check rdma_restrack_get(struct rdma_restrack_entry *res);
/**
* rdma_restrack_put() - release resource
* @res: resource entry
*/
int rdma_restrack_put(struct rdma_restrack_entry *res);
/**
* rdma_restrack_set_task() - set the task for this resource
* @res: resource entry
* @task: task struct
*/
static inline void rdma_restrack_set_task(struct rdma_restrack_entry *res,
struct task_struct *task)
{
if (res->task)
put_task_struct(res->task);
get_task_struct(task);
res->task = task;
}
#endif /* _RDMA_RESTRACK_H_ */