Merge tag 'xarray-5.1-rc1' of git://git.infradead.org/users/willy/linux-dax
[muen/linux.git] / drivers / infiniband / core / restrack.c
1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
2 /*
3  * Copyright (c) 2017-2018 Mellanox Technologies. All rights reserved.
4  */
5
6 #include <rdma/rdma_cm.h>
7 #include <rdma/ib_verbs.h>
8 #include <rdma/restrack.h>
9 #include <linux/mutex.h>
10 #include <linux/sched/task.h>
11 #include <linux/pid_namespace.h>
12
13 #include "cma_priv.h"
14 #include "restrack.h"
15
16 /**
17  * rdma_restrack_init() - initialize and allocate resource tracking
18  * @dev:  IB device
19  *
20  * Return: 0 on success
21  */
22 int rdma_restrack_init(struct ib_device *dev)
23 {
24         struct rdma_restrack_root *rt;
25         int i;
26
27         dev->res = kcalloc(RDMA_RESTRACK_MAX, sizeof(*rt), GFP_KERNEL);
28         if (!dev->res)
29                 return -ENOMEM;
30
31         rt = dev->res;
32
33         for (i = 0; i < RDMA_RESTRACK_MAX; i++)
34                 xa_init_flags(&rt[i].xa, XA_FLAGS_ALLOC);
35
36         return 0;
37 }
38
39 static const char *type2str(enum rdma_restrack_type type)
40 {
41         static const char * const names[RDMA_RESTRACK_MAX] = {
42                 [RDMA_RESTRACK_PD] = "PD",
43                 [RDMA_RESTRACK_CQ] = "CQ",
44                 [RDMA_RESTRACK_QP] = "QP",
45                 [RDMA_RESTRACK_CM_ID] = "CM_ID",
46                 [RDMA_RESTRACK_MR] = "MR",
47                 [RDMA_RESTRACK_CTX] = "CTX",
48         };
49
50         return names[type];
51 };
52
53 /**
54  * rdma_restrack_clean() - clean resource tracking
55  * @dev:  IB device
56  */
57 void rdma_restrack_clean(struct ib_device *dev)
58 {
59         struct rdma_restrack_root *rt = dev->res;
60         struct rdma_restrack_entry *e;
61         char buf[TASK_COMM_LEN];
62         bool found = false;
63         const char *owner;
64         int i;
65
66         for (i = 0 ; i < RDMA_RESTRACK_MAX; i++) {
67                 struct xarray *xa = &dev->res[i].xa;
68
69                 if (!xa_empty(xa)) {
70                         unsigned long index;
71
72                         if (!found) {
73                                 pr_err("restrack: %s", CUT_HERE);
74                                 dev_err(&dev->dev, "BUG: RESTRACK detected leak of resources\n");
75                         }
76                         xa_for_each(xa, index, e) {
77                                 if (rdma_is_kernel_res(e)) {
78                                         owner = e->kern_name;
79                                 } else {
80                                         /*
81                                          * There is no need to call get_task_struct here,
82                                          * because we can be here only if there are more
83                                          * get_task_struct() call than put_task_struct().
84                                          */
85                                         get_task_comm(buf, e->task);
86                                         owner = buf;
87                                 }
88
89                                 pr_err("restrack: %s %s object allocated by %s is not freed\n",
90                                        rdma_is_kernel_res(e) ? "Kernel" :
91                                                                "User",
92                                        type2str(e->type), owner);
93                         }
94                         found = true;
95                 }
96                 xa_destroy(xa);
97         }
98         if (found)
99                 pr_err("restrack: %s", CUT_HERE);
100
101         kfree(rt);
102 }
103
104 /**
105  * rdma_restrack_count() - the current usage of specific object
106  * @dev:  IB device
107  * @type: actual type of object to operate
108  * @ns:   PID namespace
109  */
110 int rdma_restrack_count(struct ib_device *dev, enum rdma_restrack_type type,
111                         struct pid_namespace *ns)
112 {
113         struct rdma_restrack_root *rt = &dev->res[type];
114         struct rdma_restrack_entry *e;
115         XA_STATE(xas, &rt->xa, 0);
116         u32 cnt = 0;
117
118         xa_lock(&rt->xa);
119         xas_for_each(&xas, e, U32_MAX) {
120                 if (ns == &init_pid_ns ||
121                     (!rdma_is_kernel_res(e) &&
122                      ns == task_active_pid_ns(e->task)))
123                         cnt++;
124         }
125         xa_unlock(&rt->xa);
126         return cnt;
127 }
128 EXPORT_SYMBOL(rdma_restrack_count);
129
130 static void set_kern_name(struct rdma_restrack_entry *res)
131 {
132         struct ib_pd *pd;
133
134         switch (res->type) {
135         case RDMA_RESTRACK_QP:
136                 pd = container_of(res, struct ib_qp, res)->pd;
137                 if (!pd) {
138                         WARN_ONCE(true, "XRC QPs are not supported\n");
139                         /* Survive, despite the programmer's error */
140                         res->kern_name = " ";
141                 }
142                 break;
143         case RDMA_RESTRACK_MR:
144                 pd = container_of(res, struct ib_mr, res)->pd;
145                 break;
146         default:
147                 /* Other types set kern_name directly */
148                 pd = NULL;
149                 break;
150         }
151
152         if (pd)
153                 res->kern_name = pd->res.kern_name;
154 }
155
156 static struct ib_device *res_to_dev(struct rdma_restrack_entry *res)
157 {
158         switch (res->type) {
159         case RDMA_RESTRACK_PD:
160                 return container_of(res, struct ib_pd, res)->device;
161         case RDMA_RESTRACK_CQ:
162                 return container_of(res, struct ib_cq, res)->device;
163         case RDMA_RESTRACK_QP:
164                 return container_of(res, struct ib_qp, res)->device;
165         case RDMA_RESTRACK_CM_ID:
166                 return container_of(res, struct rdma_id_private,
167                                     res)->id.device;
168         case RDMA_RESTRACK_MR:
169                 return container_of(res, struct ib_mr, res)->device;
170         case RDMA_RESTRACK_CTX:
171                 return container_of(res, struct ib_ucontext, res)->device;
172         default:
173                 WARN_ONCE(true, "Wrong resource tracking type %u\n", res->type);
174                 return NULL;
175         }
176 }
177
178 void rdma_restrack_set_task(struct rdma_restrack_entry *res,
179                             const char *caller)
180 {
181         if (caller) {
182                 res->kern_name = caller;
183                 return;
184         }
185
186         if (res->task)
187                 put_task_struct(res->task);
188         get_task_struct(current);
189         res->task = current;
190 }
191 EXPORT_SYMBOL(rdma_restrack_set_task);
192
193 static void rdma_restrack_add(struct rdma_restrack_entry *res)
194 {
195         struct ib_device *dev = res_to_dev(res);
196         struct rdma_restrack_root *rt;
197         int ret;
198
199         if (!dev)
200                 return;
201
202         rt = &dev->res[res->type];
203
204         kref_init(&res->kref);
205         init_completion(&res->comp);
206         if (res->type != RDMA_RESTRACK_QP)
207                 ret = xa_alloc_cyclic(&rt->xa, &res->id, res, xa_limit_32b,
208                                 &rt->next_id, GFP_KERNEL);
209         else {
210                 /* Special case to ensure that LQPN points to right QP */
211                 struct ib_qp *qp = container_of(res, struct ib_qp, res);
212
213                 ret = xa_insert(&rt->xa, qp->qp_num, res, GFP_KERNEL);
214                 res->id = ret ? 0 : qp->qp_num;
215         }
216
217         if (!ret)
218                 res->valid = true;
219 }
220
221 /**
222  * rdma_restrack_kadd() - add kernel object to the reource tracking database
223  * @res:  resource entry
224  */
225 void rdma_restrack_kadd(struct rdma_restrack_entry *res)
226 {
227         res->task = NULL;
228         set_kern_name(res);
229         res->user = false;
230         rdma_restrack_add(res);
231 }
232 EXPORT_SYMBOL(rdma_restrack_kadd);
233
234 /**
235  * rdma_restrack_uadd() - add user object to the reource tracking database
236  * @res:  resource entry
237  */
238 void rdma_restrack_uadd(struct rdma_restrack_entry *res)
239 {
240         if (res->type != RDMA_RESTRACK_CM_ID)
241                 res->task = NULL;
242
243         if (!res->task)
244                 rdma_restrack_set_task(res, NULL);
245         res->kern_name = NULL;
246
247         res->user = true;
248         rdma_restrack_add(res);
249 }
250 EXPORT_SYMBOL(rdma_restrack_uadd);
251
252 int __must_check rdma_restrack_get(struct rdma_restrack_entry *res)
253 {
254         return kref_get_unless_zero(&res->kref);
255 }
256 EXPORT_SYMBOL(rdma_restrack_get);
257
258 /**
259  * rdma_restrack_get_byid() - translate from ID to restrack object
260  * @dev: IB device
261  * @type: resource track type
262  * @id: ID to take a look
263  *
264  * Return: Pointer to restrack entry or -ENOENT in case of error.
265  */
266 struct rdma_restrack_entry *
267 rdma_restrack_get_byid(struct ib_device *dev,
268                        enum rdma_restrack_type type, u32 id)
269 {
270         struct rdma_restrack_root *rt = &dev->res[type];
271         struct rdma_restrack_entry *res;
272
273         xa_lock(&rt->xa);
274         res = xa_load(&rt->xa, id);
275         if (!res || !rdma_restrack_get(res))
276                 res = ERR_PTR(-ENOENT);
277         xa_unlock(&rt->xa);
278
279         return res;
280 }
281 EXPORT_SYMBOL(rdma_restrack_get_byid);
282
283 static void restrack_release(struct kref *kref)
284 {
285         struct rdma_restrack_entry *res;
286
287         res = container_of(kref, struct rdma_restrack_entry, kref);
288         complete(&res->comp);
289 }
290
291 int rdma_restrack_put(struct rdma_restrack_entry *res)
292 {
293         return kref_put(&res->kref, restrack_release);
294 }
295 EXPORT_SYMBOL(rdma_restrack_put);
296
297 void rdma_restrack_del(struct rdma_restrack_entry *res)
298 {
299         struct rdma_restrack_entry *old;
300         struct rdma_restrack_root *rt;
301         struct ib_device *dev;
302
303         if (!res->valid)
304                 goto out;
305
306         dev = res_to_dev(res);
307         if (WARN_ON(!dev))
308                 return;
309
310         rt = &dev->res[res->type];
311
312         old = xa_erase(&rt->xa, res->id);
313         WARN_ON(old != res);
314         res->valid = false;
315
316         rdma_restrack_put(res);
317         wait_for_completion(&res->comp);
318
319 out:
320         if (res->task) {
321                 put_task_struct(res->task);
322                 res->task = NULL;
323         }
324 }
325 EXPORT_SYMBOL(rdma_restrack_del);