xprtrdma: Properly handle exhaustion of the rb_mws list
[GitHub/moto-9609/android_kernel_motorola_exynos9610.git] / net / sunrpc / xprtrdma / xprt_rdma.h
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1/*
2 * Copyright (c) 2003-2007 Network Appliance, Inc. 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 BSD-type
8 * license below:
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 *
14 * Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 *
17 * Redistributions in binary form must reproduce the above
18 * copyright notice, this list of conditions and the following
19 * disclaimer in the documentation and/or other materials provided
20 * with the distribution.
21 *
22 * Neither the name of the Network Appliance, Inc. nor the names of
23 * its contributors may be used to endorse or promote products
24 * derived from this software without specific prior written
25 * permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 */
39
40#ifndef _LINUX_SUNRPC_XPRT_RDMA_H
41#define _LINUX_SUNRPC_XPRT_RDMA_H
42
43#include <linux/wait.h> /* wait_queue_head_t, etc */
44#include <linux/spinlock.h> /* spinlock_t, etc */
60063497 45#include <linux/atomic.h> /* atomic_t, etc */
254f91e2 46#include <linux/workqueue.h> /* struct work_struct */
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47
48#include <rdma/rdma_cm.h> /* RDMA connection api */
49#include <rdma/ib_verbs.h> /* RDMA verbs api */
50
51#include <linux/sunrpc/clnt.h> /* rpc_xprt */
52#include <linux/sunrpc/rpc_rdma.h> /* RPC/RDMA protocol */
53#include <linux/sunrpc/xprtrdma.h> /* xprt parameters */
54
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55#define RDMA_RESOLVE_TIMEOUT (5000) /* 5 seconds */
56#define RDMA_CONNECT_RETRY_MAX (2) /* retries if no listener backlog */
57
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58/*
59 * Interface Adapter -- one per transport instance
60 */
61struct rpcrdma_ia {
73806c88 62 rwlock_t ri_qplock;
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63 struct rdma_cm_id *ri_id;
64 struct ib_pd *ri_pd;
65 struct ib_mr *ri_bind_mem;
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66 u32 ri_dma_lkey;
67 int ri_have_dma_lkey;
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68 struct completion ri_done;
69 int ri_async_rc;
70 enum rpcrdma_memreg ri_memreg_strategy;
0fc6c4e7 71 unsigned int ri_max_frmr_depth;
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72};
73
74/*
75 * RDMA Endpoint -- one per transport instance
76 */
77
8301a2c0 78#define RPCRDMA_WC_BUDGET (128)
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79#define RPCRDMA_POLLSIZE (16)
80
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81struct rpcrdma_ep {
82 atomic_t rep_cqcount;
83 int rep_cqinit;
84 int rep_connected;
85 struct rpcrdma_ia *rep_ia;
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86 struct ib_qp_init_attr rep_attr;
87 wait_queue_head_t rep_connect_wait;
88 struct ib_sge rep_pad; /* holds zeroed pad */
89 struct ib_mr *rep_pad_mr; /* holds zeroed pad */
90 void (*rep_func)(struct rpcrdma_ep *);
91 struct rpc_xprt *rep_xprt; /* for rep_func */
92 struct rdma_conn_param rep_remote_cma;
93 struct sockaddr_storage rep_remote_addr;
254f91e2 94 struct delayed_work rep_connect_worker;
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95 struct ib_wc rep_send_wcs[RPCRDMA_POLLSIZE];
96 struct ib_wc rep_recv_wcs[RPCRDMA_POLLSIZE];
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97};
98
99#define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
100#define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)
101
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102enum rpcrdma_chunktype {
103 rpcrdma_noch = 0,
104 rpcrdma_readch,
105 rpcrdma_areadch,
106 rpcrdma_writech,
107 rpcrdma_replych
108};
109
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110/*
111 * struct rpcrdma_rep -- this structure encapsulates state required to recv
112 * and complete a reply, asychronously. It needs several pieces of
113 * state:
114 * o recv buffer (posted to provider)
115 * o ib_sge (also donated to provider)
116 * o status of reply (length, success or not)
117 * o bookkeeping state to get run by tasklet (list, etc)
118 *
119 * These are allocated during initialization, per-transport instance;
120 * however, the tasklet execution list itself is global, as it should
121 * always be pretty short.
122 *
123 * N of these are associated with a transport instance, and stored in
124 * struct rpcrdma_buffer. N is the max number of outstanding requests.
125 */
126
127/* temporary static scatter/gather max */
2773395b 128#define RPCRDMA_MAX_DATA_SEGS (64) /* max scatter/gather */
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129#define RPCRDMA_MAX_SEGS (RPCRDMA_MAX_DATA_SEGS + 2) /* head+tail = 2 */
130#define MAX_RPCRDMAHDR (\
131 /* max supported RPC/RDMA header */ \
132 sizeof(struct rpcrdma_msg) + (2 * sizeof(u32)) + \
133 (sizeof(struct rpcrdma_read_chunk) * RPCRDMA_MAX_SEGS) + sizeof(u32))
134
135struct rpcrdma_buffer;
136
137struct rpcrdma_rep {
138 unsigned int rr_len; /* actual received reply length */
139 struct rpcrdma_buffer *rr_buffer; /* home base for this structure */
140 struct rpc_xprt *rr_xprt; /* needed for request/reply matching */
141 void (*rr_func)(struct rpcrdma_rep *);/* called by tasklet in softint */
142 struct list_head rr_list; /* tasklet list */
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143 struct ib_sge rr_iov; /* for posting */
144 struct ib_mr *rr_handle; /* handle for mem in rr_iov */
145 char rr_base[MAX_RPCRDMAHDR]; /* minimal inline receive buffer */
146};
147
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148/*
149 * struct rpcrdma_mw - external memory region metadata
150 *
151 * An external memory region is any buffer or page that is registered
152 * on the fly (ie, not pre-registered).
153 *
3111d72c 154 * Each rpcrdma_buffer has a list of free MWs anchored in rb_mws. During
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155 * call_allocate, rpcrdma_buffer_get() assigns one to each segment in
156 * an rpcrdma_req. Then rpcrdma_register_external() grabs these to keep
157 * track of registration metadata while each RPC is pending.
158 * rpcrdma_deregister_external() uses this metadata to unmap and
159 * release these resources when an RPC is complete.
160 */
161enum rpcrdma_frmr_state {
162 FRMR_IS_INVALID, /* ready to be used */
163 FRMR_IS_VALID, /* in use */
164};
165
166struct rpcrdma_frmr {
167 struct ib_fast_reg_page_list *fr_pgl;
168 struct ib_mr *fr_mr;
169 enum rpcrdma_frmr_state fr_state;
170};
171
172struct rpcrdma_mw {
173 union {
174 struct ib_fmr *fmr;
175 struct rpcrdma_frmr frmr;
176 } r;
177 struct list_head mw_list;
3111d72c 178 struct list_head mw_all;
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179};
180
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181/*
182 * struct rpcrdma_req -- structure central to the request/reply sequence.
183 *
184 * N of these are associated with a transport instance, and stored in
185 * struct rpcrdma_buffer. N is the max number of outstanding requests.
186 *
187 * It includes pre-registered buffer memory for send AND recv.
188 * The recv buffer, however, is not owned by this structure, and
189 * is "donated" to the hardware when a recv is posted. When a
190 * reply is handled, the recv buffer used is given back to the
191 * struct rpcrdma_req associated with the request.
192 *
193 * In addition to the basic memory, this structure includes an array
194 * of iovs for send operations. The reason is that the iovs passed to
195 * ib_post_{send,recv} must not be modified until the work request
196 * completes.
197 *
198 * NOTES:
199 * o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we
200 * marshal. The number needed varies depending on the iov lists that
201 * are passed to us, the memory registration mode we are in, and if
202 * physical addressing is used, the layout.
203 */
204
205struct rpcrdma_mr_seg { /* chunk descriptors */
206 union { /* chunk memory handles */
207 struct ib_mr *rl_mr; /* if registered directly */
0dbb4108 208 struct rpcrdma_mw *rl_mw; /* if registered from region */
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209 } mr_chunk;
210 u64 mr_base; /* registration result */
211 u32 mr_rkey; /* registration result */
212 u32 mr_len; /* length of chunk or segment */
213 int mr_nsegs; /* number of segments in chunk or 0 */
214 enum dma_data_direction mr_dir; /* segment mapping direction */
215 dma_addr_t mr_dma; /* segment mapping address */
216 size_t mr_dmalen; /* segment mapping length */
217 struct page *mr_page; /* owning page, if any */
218 char *mr_offset; /* kva if no page, else offset */
219};
220
221struct rpcrdma_req {
222 size_t rl_size; /* actual length of buffer */
223 unsigned int rl_niovs; /* 0, 2 or 4 */
224 unsigned int rl_nchunks; /* non-zero if chunks */
575448bd 225 unsigned int rl_connect_cookie; /* retry detection */
6ab59945 226 enum rpcrdma_chunktype rl_rtype, rl_wtype;
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227 struct rpcrdma_buffer *rl_buffer; /* home base for this structure */
228 struct rpcrdma_rep *rl_reply;/* holder for reply buffer */
229 struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];/* chunk segments */
230 struct ib_sge rl_send_iov[4]; /* for active requests */
231 struct ib_sge rl_iov; /* for posting */
232 struct ib_mr *rl_handle; /* handle for mem in rl_iov */
233 char rl_base[MAX_RPCRDMAHDR]; /* start of actual buffer */
234 __u32 rl_xdr_buf[0]; /* start of returned rpc rq_buffer */
235};
236#define rpcr_to_rdmar(r) \
237 container_of((r)->rq_buffer, struct rpcrdma_req, rl_xdr_buf[0])
238
239/*
240 * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
241 * inline requests/replies, and client/server credits.
242 *
243 * One of these is associated with a transport instance
244 */
245struct rpcrdma_buffer {
246 spinlock_t rb_lock; /* protects indexes */
247 atomic_t rb_credits; /* most recent server credits */
f58851e6 248 int rb_max_requests;/* client max requests */
fe9053b3 249 struct list_head rb_mws; /* optional memory windows/fmrs/frmrs */
3111d72c 250 struct list_head rb_all;
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251 int rb_send_index;
252 struct rpcrdma_req **rb_send_bufs;
253 int rb_recv_index;
254 struct rpcrdma_rep **rb_recv_bufs;
255 char *rb_pool;
256};
257#define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
258
259/*
260 * Internal structure for transport instance creation. This
261 * exists primarily for modularity.
262 *
263 * This data should be set with mount options
264 */
265struct rpcrdma_create_data_internal {
266 struct sockaddr_storage addr; /* RDMA server address */
267 unsigned int max_requests; /* max requests (slots) in flight */
268 unsigned int rsize; /* mount rsize - max read hdr+data */
269 unsigned int wsize; /* mount wsize - max write hdr+data */
270 unsigned int inline_rsize; /* max non-rdma read data payload */
271 unsigned int inline_wsize; /* max non-rdma write data payload */
272 unsigned int padding; /* non-rdma write header padding */
273};
274
275#define RPCRDMA_INLINE_READ_THRESHOLD(rq) \
a4f0835c 276 (rpcx_to_rdmad(rq->rq_xprt).inline_rsize)
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277
278#define RPCRDMA_INLINE_WRITE_THRESHOLD(rq)\
a4f0835c 279 (rpcx_to_rdmad(rq->rq_xprt).inline_wsize)
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280
281#define RPCRDMA_INLINE_PAD_VALUE(rq)\
a4f0835c 282 rpcx_to_rdmad(rq->rq_xprt).padding
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283
284/*
285 * Statistics for RPCRDMA
286 */
287struct rpcrdma_stats {
288 unsigned long read_chunk_count;
289 unsigned long write_chunk_count;
290 unsigned long reply_chunk_count;
291
292 unsigned long long total_rdma_request;
293 unsigned long long total_rdma_reply;
294
295 unsigned long long pullup_copy_count;
296 unsigned long long fixup_copy_count;
297 unsigned long hardway_register_count;
298 unsigned long failed_marshal_count;
299 unsigned long bad_reply_count;
300};
301
302/*
303 * RPCRDMA transport -- encapsulates the structures above for
304 * integration with RPC.
305 *
306 * The contained structures are embedded, not pointers,
307 * for convenience. This structure need not be visible externally.
308 *
309 * It is allocated and initialized during mount, and released
310 * during unmount.
311 */
312struct rpcrdma_xprt {
313 struct rpc_xprt xprt;
314 struct rpcrdma_ia rx_ia;
315 struct rpcrdma_ep rx_ep;
316 struct rpcrdma_buffer rx_buf;
317 struct rpcrdma_create_data_internal rx_data;
318 struct delayed_work rdma_connect;
319 struct rpcrdma_stats rx_stats;
320};
321
322#define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, xprt)
323#define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
324
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325/* Setting this to 0 ensures interoperability with early servers.
326 * Setting this to 1 enhances certain unaligned read/write performance.
327 * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
328extern int xprt_rdma_pad_optimize;
329
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330/*
331 * Interface Adapter calls - xprtrdma/verbs.c
332 */
333int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int);
334void rpcrdma_ia_close(struct rpcrdma_ia *);
335
336/*
337 * Endpoint calls - xprtrdma/verbs.c
338 */
339int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
340 struct rpcrdma_create_data_internal *);
7f1d5419 341void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
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342int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
343int rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
344
345int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
346 struct rpcrdma_req *);
347int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
348 struct rpcrdma_rep *);
349
350/*
351 * Buffer calls - xprtrdma/verbs.c
352 */
353int rpcrdma_buffer_create(struct rpcrdma_buffer *, struct rpcrdma_ep *,
354 struct rpcrdma_ia *,
355 struct rpcrdma_create_data_internal *);
356void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
357
358struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
359void rpcrdma_buffer_put(struct rpcrdma_req *);
360void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
361void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
362
363int rpcrdma_register_internal(struct rpcrdma_ia *, void *, int,
364 struct ib_mr **, struct ib_sge *);
365int rpcrdma_deregister_internal(struct rpcrdma_ia *,
366 struct ib_mr *, struct ib_sge *);
367
368int rpcrdma_register_external(struct rpcrdma_mr_seg *,
369 int, int, struct rpcrdma_xprt *);
370int rpcrdma_deregister_external(struct rpcrdma_mr_seg *,
13c9ff8f 371 struct rpcrdma_xprt *);
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372
373/*
374 * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
375 */
254f91e2 376void rpcrdma_connect_worker(struct work_struct *);
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377void rpcrdma_conn_func(struct rpcrdma_ep *);
378void rpcrdma_reply_handler(struct rpcrdma_rep *);
379
380/*
381 * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
382 */
6ab59945 383ssize_t rpcrdma_marshal_chunks(struct rpc_rqst *, ssize_t);
f58851e6 384int rpcrdma_marshal_req(struct rpc_rqst *);
43e95988 385size_t rpcrdma_max_payload(struct rpcrdma_xprt *);
f58851e6 386
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387/* Temporary NFS request map cache. Created in svc_rdma.c */
388extern struct kmem_cache *svc_rdma_map_cachep;
389/* WR context cache. Created in svc_rdma.c */
390extern struct kmem_cache *svc_rdma_ctxt_cachep;
391/* Workqueue created in svc_rdma.c */
392extern struct workqueue_struct *svc_rdma_wq;
393
f58851e6 394#endif /* _LINUX_SUNRPC_XPRT_RDMA_H */