GNU Linux-libre 6.6.31-gnu
[releases.git] / net / rds / message.c
1 /*
2  * Copyright (c) 2006, 2020 Oracle and/or its affiliates.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  *
32  */
33 #include <linux/kernel.h>
34 #include <linux/slab.h>
35 #include <linux/export.h>
36 #include <linux/skbuff.h>
37 #include <linux/list.h>
38 #include <linux/errqueue.h>
39
40 #include "rds.h"
41
42 static unsigned int     rds_exthdr_size[__RDS_EXTHDR_MAX] = {
43 [RDS_EXTHDR_NONE]       = 0,
44 [RDS_EXTHDR_VERSION]    = sizeof(struct rds_ext_header_version),
45 [RDS_EXTHDR_RDMA]       = sizeof(struct rds_ext_header_rdma),
46 [RDS_EXTHDR_RDMA_DEST]  = sizeof(struct rds_ext_header_rdma_dest),
47 [RDS_EXTHDR_NPATHS]     = sizeof(u16),
48 [RDS_EXTHDR_GEN_NUM]    = sizeof(u32),
49 };
50
51 void rds_message_addref(struct rds_message *rm)
52 {
53         rdsdebug("addref rm %p ref %d\n", rm, refcount_read(&rm->m_refcount));
54         refcount_inc(&rm->m_refcount);
55 }
56 EXPORT_SYMBOL_GPL(rds_message_addref);
57
58 static inline bool rds_zcookie_add(struct rds_msg_zcopy_info *info, u32 cookie)
59 {
60         struct rds_zcopy_cookies *ck = &info->zcookies;
61         int ncookies = ck->num;
62
63         if (ncookies == RDS_MAX_ZCOOKIES)
64                 return false;
65         ck->cookies[ncookies] = cookie;
66         ck->num =  ++ncookies;
67         return true;
68 }
69
70 static struct rds_msg_zcopy_info *rds_info_from_znotifier(struct rds_znotifier *znotif)
71 {
72         return container_of(znotif, struct rds_msg_zcopy_info, znotif);
73 }
74
75 void rds_notify_msg_zcopy_purge(struct rds_msg_zcopy_queue *q)
76 {
77         unsigned long flags;
78         LIST_HEAD(copy);
79         struct rds_msg_zcopy_info *info, *tmp;
80
81         spin_lock_irqsave(&q->lock, flags);
82         list_splice(&q->zcookie_head, &copy);
83         INIT_LIST_HEAD(&q->zcookie_head);
84         spin_unlock_irqrestore(&q->lock, flags);
85
86         list_for_each_entry_safe(info, tmp, &copy, rs_zcookie_next) {
87                 list_del(&info->rs_zcookie_next);
88                 kfree(info);
89         }
90 }
91
92 static void rds_rm_zerocopy_callback(struct rds_sock *rs,
93                                      struct rds_znotifier *znotif)
94 {
95         struct rds_msg_zcopy_info *info;
96         struct rds_msg_zcopy_queue *q;
97         u32 cookie = znotif->z_cookie;
98         struct rds_zcopy_cookies *ck;
99         struct list_head *head;
100         unsigned long flags;
101
102         mm_unaccount_pinned_pages(&znotif->z_mmp);
103         q = &rs->rs_zcookie_queue;
104         spin_lock_irqsave(&q->lock, flags);
105         head = &q->zcookie_head;
106         if (!list_empty(head)) {
107                 info = list_first_entry(head, struct rds_msg_zcopy_info,
108                                         rs_zcookie_next);
109                 if (rds_zcookie_add(info, cookie)) {
110                         spin_unlock_irqrestore(&q->lock, flags);
111                         kfree(rds_info_from_znotifier(znotif));
112                         /* caller invokes rds_wake_sk_sleep() */
113                         return;
114                 }
115         }
116
117         info = rds_info_from_znotifier(znotif);
118         ck = &info->zcookies;
119         memset(ck, 0, sizeof(*ck));
120         WARN_ON(!rds_zcookie_add(info, cookie));
121         list_add_tail(&info->rs_zcookie_next, &q->zcookie_head);
122
123         spin_unlock_irqrestore(&q->lock, flags);
124         /* caller invokes rds_wake_sk_sleep() */
125 }
126
127 /*
128  * This relies on dma_map_sg() not touching sg[].page during merging.
129  */
130 static void rds_message_purge(struct rds_message *rm)
131 {
132         unsigned long i, flags;
133         bool zcopy = false;
134
135         if (unlikely(test_bit(RDS_MSG_PAGEVEC, &rm->m_flags)))
136                 return;
137
138         spin_lock_irqsave(&rm->m_rs_lock, flags);
139         if (rm->m_rs) {
140                 struct rds_sock *rs = rm->m_rs;
141
142                 if (rm->data.op_mmp_znotifier) {
143                         zcopy = true;
144                         rds_rm_zerocopy_callback(rs, rm->data.op_mmp_znotifier);
145                         rds_wake_sk_sleep(rs);
146                         rm->data.op_mmp_znotifier = NULL;
147                 }
148                 sock_put(rds_rs_to_sk(rs));
149                 rm->m_rs = NULL;
150         }
151         spin_unlock_irqrestore(&rm->m_rs_lock, flags);
152
153         for (i = 0; i < rm->data.op_nents; i++) {
154                 /* XXX will have to put_page for page refs */
155                 if (!zcopy)
156                         __free_page(sg_page(&rm->data.op_sg[i]));
157                 else
158                         put_page(sg_page(&rm->data.op_sg[i]));
159         }
160         rm->data.op_nents = 0;
161
162         if (rm->rdma.op_active)
163                 rds_rdma_free_op(&rm->rdma);
164         if (rm->rdma.op_rdma_mr)
165                 kref_put(&rm->rdma.op_rdma_mr->r_kref, __rds_put_mr_final);
166
167         if (rm->atomic.op_active)
168                 rds_atomic_free_op(&rm->atomic);
169         if (rm->atomic.op_rdma_mr)
170                 kref_put(&rm->atomic.op_rdma_mr->r_kref, __rds_put_mr_final);
171 }
172
173 void rds_message_put(struct rds_message *rm)
174 {
175         rdsdebug("put rm %p ref %d\n", rm, refcount_read(&rm->m_refcount));
176         WARN(!refcount_read(&rm->m_refcount), "danger refcount zero on %p\n", rm);
177         if (refcount_dec_and_test(&rm->m_refcount)) {
178                 BUG_ON(!list_empty(&rm->m_sock_item));
179                 BUG_ON(!list_empty(&rm->m_conn_item));
180                 rds_message_purge(rm);
181
182                 kfree(rm);
183         }
184 }
185 EXPORT_SYMBOL_GPL(rds_message_put);
186
187 void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
188                                  __be16 dport, u64 seq)
189 {
190         hdr->h_flags = 0;
191         hdr->h_sport = sport;
192         hdr->h_dport = dport;
193         hdr->h_sequence = cpu_to_be64(seq);
194         hdr->h_exthdr[0] = RDS_EXTHDR_NONE;
195 }
196 EXPORT_SYMBOL_GPL(rds_message_populate_header);
197
198 int rds_message_add_extension(struct rds_header *hdr, unsigned int type,
199                               const void *data, unsigned int len)
200 {
201         unsigned int ext_len = sizeof(u8) + len;
202         unsigned char *dst;
203
204         /* For now, refuse to add more than one extension header */
205         if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE)
206                 return 0;
207
208         if (type >= __RDS_EXTHDR_MAX || len != rds_exthdr_size[type])
209                 return 0;
210
211         if (ext_len >= RDS_HEADER_EXT_SPACE)
212                 return 0;
213         dst = hdr->h_exthdr;
214
215         *dst++ = type;
216         memcpy(dst, data, len);
217
218         dst[len] = RDS_EXTHDR_NONE;
219         return 1;
220 }
221 EXPORT_SYMBOL_GPL(rds_message_add_extension);
222
223 /*
224  * If a message has extension headers, retrieve them here.
225  * Call like this:
226  *
227  * unsigned int pos = 0;
228  *
229  * while (1) {
230  *      buflen = sizeof(buffer);
231  *      type = rds_message_next_extension(hdr, &pos, buffer, &buflen);
232  *      if (type == RDS_EXTHDR_NONE)
233  *              break;
234  *      ...
235  * }
236  */
237 int rds_message_next_extension(struct rds_header *hdr,
238                 unsigned int *pos, void *buf, unsigned int *buflen)
239 {
240         unsigned int offset, ext_type, ext_len;
241         u8 *src = hdr->h_exthdr;
242
243         offset = *pos;
244         if (offset >= RDS_HEADER_EXT_SPACE)
245                 goto none;
246
247         /* Get the extension type and length. For now, the
248          * length is implied by the extension type. */
249         ext_type = src[offset++];
250
251         if (ext_type == RDS_EXTHDR_NONE || ext_type >= __RDS_EXTHDR_MAX)
252                 goto none;
253         ext_len = rds_exthdr_size[ext_type];
254         if (offset + ext_len > RDS_HEADER_EXT_SPACE)
255                 goto none;
256
257         *pos = offset + ext_len;
258         if (ext_len < *buflen)
259                 *buflen = ext_len;
260         memcpy(buf, src + offset, *buflen);
261         return ext_type;
262
263 none:
264         *pos = RDS_HEADER_EXT_SPACE;
265         *buflen = 0;
266         return RDS_EXTHDR_NONE;
267 }
268
269 int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset)
270 {
271         struct rds_ext_header_rdma_dest ext_hdr;
272
273         ext_hdr.h_rdma_rkey = cpu_to_be32(r_key);
274         ext_hdr.h_rdma_offset = cpu_to_be32(offset);
275         return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr));
276 }
277 EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension);
278
279 /*
280  * Each rds_message is allocated with extra space for the scatterlist entries
281  * rds ops will need. This is to minimize memory allocation count. Then, each rds op
282  * can grab SGs when initializing its part of the rds_message.
283  */
284 struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp)
285 {
286         struct rds_message *rm;
287
288         if (extra_len > KMALLOC_MAX_SIZE - sizeof(struct rds_message))
289                 return NULL;
290
291         rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp);
292         if (!rm)
293                 goto out;
294
295         rm->m_used_sgs = 0;
296         rm->m_total_sgs = extra_len / sizeof(struct scatterlist);
297
298         refcount_set(&rm->m_refcount, 1);
299         INIT_LIST_HEAD(&rm->m_sock_item);
300         INIT_LIST_HEAD(&rm->m_conn_item);
301         spin_lock_init(&rm->m_rs_lock);
302         init_waitqueue_head(&rm->m_flush_wait);
303
304 out:
305         return rm;
306 }
307
308 /*
309  * RDS ops use this to grab SG entries from the rm's sg pool.
310  */
311 struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents)
312 {
313         struct scatterlist *sg_first = (struct scatterlist *) &rm[1];
314         struct scatterlist *sg_ret;
315
316         if (nents <= 0) {
317                 pr_warn("rds: alloc sgs failed! nents <= 0\n");
318                 return ERR_PTR(-EINVAL);
319         }
320
321         if (rm->m_used_sgs + nents > rm->m_total_sgs) {
322                 pr_warn("rds: alloc sgs failed! total %d used %d nents %d\n",
323                         rm->m_total_sgs, rm->m_used_sgs, nents);
324                 return ERR_PTR(-ENOMEM);
325         }
326
327         sg_ret = &sg_first[rm->m_used_sgs];
328         sg_init_table(sg_ret, nents);
329         rm->m_used_sgs += nents;
330
331         return sg_ret;
332 }
333
334 struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len)
335 {
336         struct rds_message *rm;
337         unsigned int i;
338         int num_sgs = DIV_ROUND_UP(total_len, PAGE_SIZE);
339         int extra_bytes = num_sgs * sizeof(struct scatterlist);
340
341         rm = rds_message_alloc(extra_bytes, GFP_NOWAIT);
342         if (!rm)
343                 return ERR_PTR(-ENOMEM);
344
345         set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
346         rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
347         rm->data.op_nents = DIV_ROUND_UP(total_len, PAGE_SIZE);
348         rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
349         if (IS_ERR(rm->data.op_sg)) {
350                 void *err = ERR_CAST(rm->data.op_sg);
351                 rds_message_put(rm);
352                 return err;
353         }
354
355         for (i = 0; i < rm->data.op_nents; ++i) {
356                 sg_set_page(&rm->data.op_sg[i],
357                                 virt_to_page((void *)page_addrs[i]),
358                                 PAGE_SIZE, 0);
359         }
360
361         return rm;
362 }
363
364 static int rds_message_zcopy_from_user(struct rds_message *rm, struct iov_iter *from)
365 {
366         struct scatterlist *sg;
367         int ret = 0;
368         int length = iov_iter_count(from);
369         struct rds_msg_zcopy_info *info;
370
371         rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from));
372
373         /*
374          * now allocate and copy in the data payload.
375          */
376         sg = rm->data.op_sg;
377
378         info = kzalloc(sizeof(*info), GFP_KERNEL);
379         if (!info)
380                 return -ENOMEM;
381         INIT_LIST_HEAD(&info->rs_zcookie_next);
382         rm->data.op_mmp_znotifier = &info->znotif;
383         if (mm_account_pinned_pages(&rm->data.op_mmp_znotifier->z_mmp,
384                                     length)) {
385                 ret = -ENOMEM;
386                 goto err;
387         }
388         while (iov_iter_count(from)) {
389                 struct page *pages;
390                 size_t start;
391                 ssize_t copied;
392
393                 copied = iov_iter_get_pages2(from, &pages, PAGE_SIZE,
394                                             1, &start);
395                 if (copied < 0) {
396                         struct mmpin *mmp;
397                         int i;
398
399                         for (i = 0; i < rm->data.op_nents; i++)
400                                 put_page(sg_page(&rm->data.op_sg[i]));
401                         mmp = &rm->data.op_mmp_znotifier->z_mmp;
402                         mm_unaccount_pinned_pages(mmp);
403                         ret = -EFAULT;
404                         goto err;
405                 }
406                 length -= copied;
407                 sg_set_page(sg, pages, copied, start);
408                 rm->data.op_nents++;
409                 sg++;
410         }
411         WARN_ON_ONCE(length != 0);
412         return ret;
413 err:
414         kfree(info);
415         rm->data.op_mmp_znotifier = NULL;
416         return ret;
417 }
418
419 int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from,
420                                bool zcopy)
421 {
422         unsigned long to_copy, nbytes;
423         unsigned long sg_off;
424         struct scatterlist *sg;
425         int ret = 0;
426
427         rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from));
428
429         /* now allocate and copy in the data payload.  */
430         sg = rm->data.op_sg;
431         sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
432
433         if (zcopy)
434                 return rds_message_zcopy_from_user(rm, from);
435
436         while (iov_iter_count(from)) {
437                 if (!sg_page(sg)) {
438                         ret = rds_page_remainder_alloc(sg, iov_iter_count(from),
439                                                        GFP_HIGHUSER);
440                         if (ret)
441                                 return ret;
442                         rm->data.op_nents++;
443                         sg_off = 0;
444                 }
445
446                 to_copy = min_t(unsigned long, iov_iter_count(from),
447                                 sg->length - sg_off);
448
449                 rds_stats_add(s_copy_from_user, to_copy);
450                 nbytes = copy_page_from_iter(sg_page(sg), sg->offset + sg_off,
451                                              to_copy, from);
452                 if (nbytes != to_copy)
453                         return -EFAULT;
454
455                 sg_off += to_copy;
456
457                 if (sg_off == sg->length)
458                         sg++;
459         }
460
461         return ret;
462 }
463
464 int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
465 {
466         struct rds_message *rm;
467         struct scatterlist *sg;
468         unsigned long to_copy;
469         unsigned long vec_off;
470         int copied;
471         int ret;
472         u32 len;
473
474         rm = container_of(inc, struct rds_message, m_inc);
475         len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
476
477         sg = rm->data.op_sg;
478         vec_off = 0;
479         copied = 0;
480
481         while (iov_iter_count(to) && copied < len) {
482                 to_copy = min_t(unsigned long, iov_iter_count(to),
483                                 sg->length - vec_off);
484                 to_copy = min_t(unsigned long, to_copy, len - copied);
485
486                 rds_stats_add(s_copy_to_user, to_copy);
487                 ret = copy_page_to_iter(sg_page(sg), sg->offset + vec_off,
488                                         to_copy, to);
489                 if (ret != to_copy)
490                         return -EFAULT;
491
492                 vec_off += to_copy;
493                 copied += to_copy;
494
495                 if (vec_off == sg->length) {
496                         vec_off = 0;
497                         sg++;
498                 }
499         }
500
501         return copied;
502 }
503
504 /*
505  * If the message is still on the send queue, wait until the transport
506  * is done with it. This is particularly important for RDMA operations.
507  */
508 void rds_message_wait(struct rds_message *rm)
509 {
510         wait_event_interruptible(rm->m_flush_wait,
511                         !test_bit(RDS_MSG_MAPPED, &rm->m_flags));
512 }
513
514 void rds_message_unmapped(struct rds_message *rm)
515 {
516         clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
517         wake_up_interruptible(&rm->m_flush_wait);
518 }
519 EXPORT_SYMBOL_GPL(rds_message_unmapped);