net/rds/message.c

   1 /*
   2  * Copyright (c) 2006 Oracle.  All rights reserved.
   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
  52 void rds_message_addref(struct rds_message *rm)
  53 {
  54         rdsdebug("addref rm %p ref %d\n", rm, refcount_read(&rm->m_refcount));
  55         refcount_inc(&rm->m_refcount);
  56 }
  57 EXPORT_SYMBOL_GPL(rds_message_addref);
  58
  59 static inline bool skb_zcookie_add(struct sk_buff *skb, u32 cookie)
  60 {
  61         struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
  62         int ncookies;
  63         u32 *ptr;
  64
  65         if (serr->ee.ee_origin != SO_EE_ORIGIN_ZCOOKIE)
  66                 return false;
  67         ncookies = serr->ee.ee_data;
  68         if (ncookies == SO_EE_ORIGIN_MAX_ZCOOKIES)
  69                 return false;
  70         ptr = skb_put(skb, sizeof(u32));
  71         *ptr = cookie;
  72         serr->ee.ee_data = ++ncookies;
  73         return true;
  74 }
  75
  76 static void rds_rm_zerocopy_callback(struct rds_sock *rs,
  77                                      struct rds_znotifier *znotif)
  78 {
  79         struct sock *sk = rds_rs_to_sk(rs);
  80         struct sk_buff *skb, *tail;
  81         struct sock_exterr_skb *serr;
  82         unsigned long flags;
  83         struct sk_buff_head *q;
  84         u32 cookie = znotif->z_cookie;
  85
  86         q = &sk->sk_error_queue;
  87         spin_lock_irqsave(&q->lock, flags);
  88         tail = skb_peek_tail(q);
  89
  90         if (tail && skb_zcookie_add(tail, cookie)) {
  91                 spin_unlock_irqrestore(&q->lock, flags);
  92                 mm_unaccount_pinned_pages(&znotif->z_mmp);
  93                 consume_skb(rds_skb_from_znotifier(znotif));
  94                 sk->sk_error_report(sk);
  95                 return;
  96         }
  97
  98         skb = rds_skb_from_znotifier(znotif);
  99         serr = SKB_EXT_ERR(skb);
 100         memset(&serr->ee, 0, sizeof(serr->ee));
 101         serr->ee.ee_errno = 0;
 102         serr->ee.ee_origin = SO_EE_ORIGIN_ZCOOKIE;
 103         serr->ee.ee_info = 0;
 104         WARN_ON(!skb_zcookie_add(skb, cookie));
 105
 106         __skb_queue_tail(q, skb);
 107
 108         spin_unlock_irqrestore(&q->lock, flags);
 109         sk->sk_error_report(sk);
 110
 111         mm_unaccount_pinned_pages(&znotif->z_mmp);
 112 }
 113
 114 /*
 115  * This relies on dma_map_sg() not touching sg[].page during merging.
 116  */
 117 static void rds_message_purge(struct rds_message *rm)
 118 {
 119         unsigned long i, flags;
 120         bool zcopy = false;
 121
 122         if (unlikely(test_bit(RDS_MSG_PAGEVEC, &rm->m_flags)))
 123                 return;
 124
 125         spin_lock_irqsave(&rm->m_rs_lock, flags);
 126         if (rm->m_rs) {
 127                 struct rds_sock *rs = rm->m_rs;
 128
 129                 if (rm->data.op_mmp_znotifier) {
 130                         zcopy = true;
 131                         rds_rm_zerocopy_callback(rs, rm->data.op_mmp_znotifier);
 132                         rm->data.op_mmp_znotifier = NULL;
 133                 }
 134                 sock_put(rds_rs_to_sk(rs));
 135                 rm->m_rs = NULL;
 136         }
 137         spin_unlock_irqrestore(&rm->m_rs_lock, flags);
 138
 139         for (i = 0; i < rm->data.op_nents; i++) {
 140                 /* XXX will have to put_page for page refs */
 141                 if (!zcopy)
 142                         __free_page(sg_page(&rm->data.op_sg[i]));
 143                 else
 144                         put_page(sg_page(&rm->data.op_sg[i]));
 145         }
 146         rm->data.op_nents = 0;
 147
 148         if (rm->rdma.op_active)
 149                 rds_rdma_free_op(&rm->rdma);
 150         if (rm->rdma.op_rdma_mr)
 151                 rds_mr_put(rm->rdma.op_rdma_mr);
 152
 153         if (rm->atomic.op_active)
 154                 rds_atomic_free_op(&rm->atomic);
 155         if (rm->atomic.op_rdma_mr)
 156                 rds_mr_put(rm->atomic.op_rdma_mr);
 157 }
 158
 159 void rds_message_put(struct rds_message *rm)
 160 {
 161         rdsdebug("put rm %p ref %d\n", rm, refcount_read(&rm->m_refcount));
 162         WARN(!refcount_read(&rm->m_refcount), "danger refcount zero on %p\n", rm);
 163         if (refcount_dec_and_test(&rm->m_refcount)) {
 164                 BUG_ON(!list_empty(&rm->m_sock_item));
 165                 BUG_ON(!list_empty(&rm->m_conn_item));
 166                 rds_message_purge(rm);
 167
 168                 kfree(rm);
 169         }
 170 }
 171 EXPORT_SYMBOL_GPL(rds_message_put);
 172
 173 void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
 174                                  __be16 dport, u64 seq)
 175 {
 176         hdr->h_flags = 0;
 177         hdr->h_sport = sport;
 178         hdr->h_dport = dport;
 179         hdr->h_sequence = cpu_to_be64(seq);
 180         hdr->h_exthdr[0] = RDS_EXTHDR_NONE;
 181 }
 182 EXPORT_SYMBOL_GPL(rds_message_populate_header);
 183
 184 int rds_message_add_extension(struct rds_header *hdr, unsigned int type,
 185                               const void *data, unsigned int len)
 186 {
 187         unsigned int ext_len = sizeof(u8) + len;
 188         unsigned char *dst;
 189
 190         /* For now, refuse to add more than one extension header */
 191         if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE)
 192                 return 0;
 193
 194         if (type >= __RDS_EXTHDR_MAX || len != rds_exthdr_size[type])
 195                 return 0;
 196
 197         if (ext_len >= RDS_HEADER_EXT_SPACE)
 198                 return 0;
 199         dst = hdr->h_exthdr;
 200
 201         *dst++ = type;
 202         memcpy(dst, data, len);
 203
 204         dst[len] = RDS_EXTHDR_NONE;
 205         return 1;
 206 }
 207 EXPORT_SYMBOL_GPL(rds_message_add_extension);
 208
 209 /*
 210  * If a message has extension headers, retrieve them here.
 211  * Call like this:
 212  *
 213  * unsigned int pos = 0;
 214  *
 215  * while (1) {
 216  *      buflen = sizeof(buffer);
 217  *      type = rds_message_next_extension(hdr, &pos, buffer, &buflen);
 218  *      if (type == RDS_EXTHDR_NONE)
 219  *              break;
 220  *      ...
 221  * }
 222  */
 223 int rds_message_next_extension(struct rds_header *hdr,
 224                 unsigned int *pos, void *buf, unsigned int *buflen)
 225 {
 226         unsigned int offset, ext_type, ext_len;
 227         u8 *src = hdr->h_exthdr;
 228
 229         offset = *pos;
 230         if (offset >= RDS_HEADER_EXT_SPACE)
 231                 goto none;
 232
 233         /* Get the extension type and length. For now, the
 234          * length is implied by the extension type. */
 235         ext_type = src[offset++];
 236
 237         if (ext_type == RDS_EXTHDR_NONE || ext_type >= __RDS_EXTHDR_MAX)
 238                 goto none;
 239         ext_len = rds_exthdr_size[ext_type];
 240         if (offset + ext_len > RDS_HEADER_EXT_SPACE)
 241                 goto none;
 242
 243         *pos = offset + ext_len;
 244         if (ext_len < *buflen)
 245                 *buflen = ext_len;
 246         memcpy(buf, src + offset, *buflen);
 247         return ext_type;
 248
 249 none:
 250         *pos = RDS_HEADER_EXT_SPACE;
 251         *buflen = 0;
 252         return RDS_EXTHDR_NONE;
 253 }
 254
 255 int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset)
 256 {
 257         struct rds_ext_header_rdma_dest ext_hdr;
 258
 259         ext_hdr.h_rdma_rkey = cpu_to_be32(r_key);
 260         ext_hdr.h_rdma_offset = cpu_to_be32(offset);
 261         return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr));
 262 }
 263 EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension);
 264
 265 /*
 266  * Each rds_message is allocated with extra space for the scatterlist entries
 267  * rds ops will need. This is to minimize memory allocation count. Then, each rds op
 268  * can grab SGs when initializing its part of the rds_message.
 269  */
 270 struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp)
 271 {
 272         struct rds_message *rm;
 273
 274         if (extra_len > KMALLOC_MAX_SIZE - sizeof(struct rds_message))
 275                 return NULL;
 276
 277         rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp);
 278         if (!rm)
 279                 goto out;
 280
 281         rm->m_used_sgs = 0;
 282         rm->m_total_sgs = extra_len / sizeof(struct scatterlist);
 283
 284         refcount_set(&rm->m_refcount, 1);
 285         INIT_LIST_HEAD(&rm->m_sock_item);
 286         INIT_LIST_HEAD(&rm->m_conn_item);
 287         spin_lock_init(&rm->m_rs_lock);
 288         init_waitqueue_head(&rm->m_flush_wait);
 289
 290 out:
 291         return rm;
 292 }
 293
 294 /*
 295  * RDS ops use this to grab SG entries from the rm's sg pool.
 296  */
 297 struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents)
 298 {
 299         struct scatterlist *sg_first = (struct scatterlist *) &rm[1];
 300         struct scatterlist *sg_ret;
 301
 302         WARN_ON(rm->m_used_sgs + nents > rm->m_total_sgs);
 303         WARN_ON(!nents);
 304
 305         if (rm->m_used_sgs + nents > rm->m_total_sgs)
 306                 return NULL;
 307
 308         sg_ret = &sg_first[rm->m_used_sgs];
 309         sg_init_table(sg_ret, nents);
 310         rm->m_used_sgs += nents;
 311
 312         return sg_ret;
 313 }
 314
 315 struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len)
 316 {
 317         struct rds_message *rm;
 318         unsigned int i;
 319         int num_sgs = ceil(total_len, PAGE_SIZE);
 320         int extra_bytes = num_sgs * sizeof(struct scatterlist);
 321
 322         rm = rds_message_alloc(extra_bytes, GFP_NOWAIT);
 323         if (!rm)
 324                 return ERR_PTR(-ENOMEM);
 325
 326         set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
 327         rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
 328         rm->data.op_nents = ceil(total_len, PAGE_SIZE);
 329         rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
 330         if (!rm->data.op_sg) {
 331                 rds_message_put(rm);
 332                 return ERR_PTR(-ENOMEM);
 333         }
 334
 335         for (i = 0; i < rm->data.op_nents; ++i) {
 336                 sg_set_page(&rm->data.op_sg[i],
 337                                 virt_to_page(page_addrs[i]),
 338                                 PAGE_SIZE, 0);
 339         }
 340
 341         return rm;
 342 }
 343
 344 int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from)
 345 {
 346         unsigned long to_copy, nbytes;
 347         unsigned long sg_off;
 348         struct scatterlist *sg;
 349         int ret = 0;
 350
 351         rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from));
 352
 353         /*
 354          * now allocate and copy in the data payload.
 355          */
 356         sg = rm->data.op_sg;
 357         sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
 358
 359         while (iov_iter_count(from)) {
 360                 if (!sg_page(sg)) {
 361                         ret = rds_page_remainder_alloc(sg, iov_iter_count(from),
 362                                                        GFP_HIGHUSER);
 363                         if (ret)
 364                                 return ret;
 365                         rm->data.op_nents++;
 366                         sg_off = 0;
 367                 }
 368
 369                 to_copy = min_t(unsigned long, iov_iter_count(from),
 370                                 sg->length - sg_off);
 371
 372                 rds_stats_add(s_copy_from_user, to_copy);
 373                 nbytes = copy_page_from_iter(sg_page(sg), sg->offset + sg_off,
 374                                              to_copy, from);
 375                 if (nbytes != to_copy)
 376                         return -EFAULT;
 377
 378                 sg_off += to_copy;
 379
 380                 if (sg_off == sg->length)
 381                         sg++;
 382         }
 383
 384         return ret;
 385 }
 386
 387 int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
 388 {
 389         struct rds_message *rm;
 390         struct scatterlist *sg;
 391         unsigned long to_copy;
 392         unsigned long vec_off;
 393         int copied;
 394         int ret;
 395         u32 len;
 396
 397         rm = container_of(inc, struct rds_message, m_inc);
 398         len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
 399
 400         sg = rm->data.op_sg;
 401         vec_off = 0;
 402         copied = 0;
 403
 404         while (iov_iter_count(to) && copied < len) {
 405                 to_copy = min_t(unsigned long, iov_iter_count(to),
 406                                 sg->length - vec_off);
 407                 to_copy = min_t(unsigned long, to_copy, len - copied);
 408
 409                 rds_stats_add(s_copy_to_user, to_copy);
 410                 ret = copy_page_to_iter(sg_page(sg), sg->offset + vec_off,
 411                                         to_copy, to);
 412                 if (ret != to_copy)
 413                         return -EFAULT;
 414
 415                 vec_off += to_copy;
 416                 copied += to_copy;
 417
 418                 if (vec_off == sg->length) {
 419                         vec_off = 0;
 420                         sg++;
 421                 }
 422         }
 423
 424         return copied;
 425 }
 426
 427 /*
 428  * If the message is still on the send queue, wait until the transport
 429  * is done with it. This is particularly important for RDMA operations.
 430  */
 431 void rds_message_wait(struct rds_message *rm)
 432 {
 433         wait_event_interruptible(rm->m_flush_wait,
 434                         !test_bit(RDS_MSG_MAPPED, &rm->m_flags));
 435 }
 436
 437 void rds_message_unmapped(struct rds_message *rm)
 438 {
 439         clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
 440         wake_up_interruptible(&rm->m_flush_wait);
 441 }
 442 EXPORT_SYMBOL_GPL(rds_message_unmapped);
 443