xref: /spdk/examples/bdev/hello_world/hello_bdev.c (revision 65e5bbdc059f740cbbe8271ddec0929ea9b9624e)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include "spdk/stdinc.h"
35 #include "spdk/thread.h"
36 #include "spdk/bdev.h"
37 #include "spdk/env.h"
38 #include "spdk/event.h"
39 #include "spdk/log.h"
40 #include "spdk/string.h"
41 #include "spdk/bdev_module.h"
42 
43 static char *g_bdev_name = "Malloc0";
44 
45 /*
46  * We'll use this struct to gather housekeeping hello_context to pass between
47  * our events and callbacks.
48  */
49 struct hello_context_t {
50 	struct spdk_bdev *bdev;
51 	struct spdk_bdev_desc *bdev_desc;
52 	struct spdk_io_channel *bdev_io_channel;
53 	char *buff;
54 	char *bdev_name;
55 	struct spdk_bdev_io_wait_entry bdev_io_wait;
56 };
57 
58 /*
59  * Usage function for printing parameters that are specific to this application
60  */
61 static void
62 hello_bdev_usage(void)
63 {
64 	printf(" -b <bdev>                 name of the bdev to use\n");
65 }
66 
67 /*
68  * This function is called to parse the parameters that are specific to this application
69  */
70 static void hello_bdev_parse_arg(int ch, char *arg)
71 {
72 	switch (ch) {
73 	case 'b':
74 		g_bdev_name = arg;
75 		break;
76 	}
77 }
78 
79 /*
80  * Callback function for read io completion.
81  */
82 static void
83 read_complete(struct spdk_bdev_io *bdev_io, bool success, void *cb_arg)
84 {
85 	struct hello_context_t *hello_context = cb_arg;
86 
87 	if (success) {
88 		SPDK_NOTICELOG("Read string from bdev : %s\n", hello_context->buff);
89 	} else {
90 		SPDK_ERRLOG("bdev io read error\n");
91 	}
92 
93 	/* Complete the bdev io and close the channel */
94 	spdk_bdev_free_io(bdev_io);
95 	spdk_put_io_channel(hello_context->bdev_io_channel);
96 	spdk_bdev_close(hello_context->bdev_desc);
97 	SPDK_NOTICELOG("Stopping app\n");
98 	spdk_app_stop(success ? 0 : -1);
99 }
100 
101 static void
102 hello_read(void *arg)
103 {
104 	struct hello_context_t *hello_context = arg;
105 	int rc = 0;
106 	uint32_t length = spdk_bdev_get_block_size(hello_context->bdev);
107 
108 	SPDK_NOTICELOG("Reading io\n");
109 	rc = spdk_bdev_read(hello_context->bdev_desc, hello_context->bdev_io_channel,
110 			    hello_context->buff, 0, length, read_complete, hello_context);
111 
112 	if (rc == -ENOMEM) {
113 		SPDK_NOTICELOG("Queueing io\n");
114 		/* In case we cannot perform I/O now, queue I/O */
115 		hello_context->bdev_io_wait.bdev = hello_context->bdev;
116 		hello_context->bdev_io_wait.cb_fn = hello_read;
117 		hello_context->bdev_io_wait.cb_arg = hello_context;
118 		spdk_bdev_queue_io_wait(hello_context->bdev, hello_context->bdev_io_channel,
119 					&hello_context->bdev_io_wait);
120 	} else if (rc) {
121 		SPDK_ERRLOG("%s error while reading from bdev: %d\n", spdk_strerror(-rc), rc);
122 		spdk_put_io_channel(hello_context->bdev_io_channel);
123 		spdk_bdev_close(hello_context->bdev_desc);
124 		spdk_app_stop(-1);
125 	}
126 }
127 
128 /*
129  * Callback function for write io completion.
130  */
131 static void
132 write_complete(struct spdk_bdev_io *bdev_io, bool success, void *cb_arg)
133 {
134 	struct hello_context_t *hello_context = cb_arg;
135 	uint32_t length;
136 
137 	/* Complete the I/O */
138 	spdk_bdev_free_io(bdev_io);
139 
140 	if (success) {
141 		SPDK_NOTICELOG("bdev io write completed successfully\n");
142 	} else {
143 		SPDK_ERRLOG("bdev io write error: %d\n", EIO);
144 		spdk_put_io_channel(hello_context->bdev_io_channel);
145 		spdk_bdev_close(hello_context->bdev_desc);
146 		spdk_app_stop(-1);
147 		return;
148 	}
149 
150 	/* Zero the buffer so that we can use it for reading */
151 	length = spdk_bdev_get_block_size(hello_context->bdev);
152 	memset(hello_context->buff, 0, length);
153 
154 	hello_read(hello_context);
155 }
156 
157 static void
158 hello_write(void *arg)
159 {
160 	struct hello_context_t *hello_context = arg;
161 	int rc = 0;
162 	uint32_t length = spdk_bdev_get_block_size(hello_context->bdev);
163 
164 	SPDK_NOTICELOG("Writing to the bdev\n");
165 	rc = spdk_bdev_write(hello_context->bdev_desc, hello_context->bdev_io_channel,
166 			     hello_context->buff, 0, length, write_complete, hello_context);
167 
168 	if (rc == -ENOMEM) {
169 		SPDK_NOTICELOG("Queueing io\n");
170 		/* In case we cannot perform I/O now, queue I/O */
171 		hello_context->bdev_io_wait.bdev = hello_context->bdev;
172 		hello_context->bdev_io_wait.cb_fn = hello_write;
173 		hello_context->bdev_io_wait.cb_arg = hello_context;
174 		spdk_bdev_queue_io_wait(hello_context->bdev, hello_context->bdev_io_channel,
175 					&hello_context->bdev_io_wait);
176 	} else if (rc) {
177 		SPDK_ERRLOG("%s error while writing to bdev: %d\n", spdk_strerror(-rc), rc);
178 		spdk_put_io_channel(hello_context->bdev_io_channel);
179 		spdk_bdev_close(hello_context->bdev_desc);
180 		spdk_app_stop(-1);
181 	}
182 }
183 
184 /*
185  * Our initial event that kicks off everything from main().
186  */
187 static void
188 hello_start(void *arg1, void *arg2)
189 {
190 	struct hello_context_t *hello_context = arg1;
191 	uint32_t blk_size, buf_align;
192 	int rc = 0;
193 	hello_context->bdev = NULL;
194 	hello_context->bdev_desc = NULL;
195 
196 	SPDK_NOTICELOG("Successfully started the application\n");
197 
198 	/*
199 	 * Get the bdev. There can be many bdevs configured in
200 	 * in the configuration file but this application will only
201 	 * use the one input by the user at runtime so we get it via its name.
202 	 */
203 	hello_context->bdev = spdk_bdev_get_by_name(hello_context->bdev_name);
204 	if (hello_context->bdev == NULL) {
205 		SPDK_ERRLOG("Could not find the bdev: %s\n", hello_context->bdev_name);
206 		spdk_app_stop(-1);
207 		return;
208 	}
209 
210 	/*
211 	 * Open the bdev by calling spdk_bdev_open()
212 	 * The function will return a descriptor
213 	 */
214 	SPDK_NOTICELOG("Opening the bdev %s\n", hello_context->bdev_name);
215 	rc = spdk_bdev_open(hello_context->bdev, true, NULL, NULL, &hello_context->bdev_desc);
216 	if (rc) {
217 		SPDK_ERRLOG("Could not open bdev: %s\n", hello_context->bdev_name);
218 		spdk_app_stop(-1);
219 		return;
220 	}
221 
222 	SPDK_NOTICELOG("Opening io channel\n");
223 	/* Open I/O channel */
224 	hello_context->bdev_io_channel = spdk_bdev_get_io_channel(hello_context->bdev_desc);
225 	if (hello_context->bdev_io_channel == NULL) {
226 		SPDK_ERRLOG("Could not create bdev I/O channel!!\n");
227 		spdk_bdev_close(hello_context->bdev_desc);
228 		spdk_app_stop(-1);
229 		return;
230 	}
231 
232 	/* Allocate memory for the write buffer.
233 	 * Initialize the write buffer with the string "Hello World!"
234 	 */
235 	blk_size = spdk_bdev_get_block_size(hello_context->bdev);
236 	buf_align = spdk_bdev_get_buf_align(hello_context->bdev);
237 	hello_context->buff = spdk_dma_zmalloc(blk_size, buf_align, NULL);
238 	if (!hello_context->buff) {
239 		SPDK_ERRLOG("Failed to allocate buffer\n");
240 		spdk_put_io_channel(hello_context->bdev_io_channel);
241 		spdk_bdev_close(hello_context->bdev_desc);
242 		spdk_app_stop(-1);
243 		return;
244 	}
245 	snprintf(hello_context->buff, blk_size, "%s", "Hello World!\n");
246 
247 	hello_write(hello_context);
248 }
249 
250 int
251 main(int argc, char **argv)
252 {
253 	struct spdk_app_opts opts = {};
254 	int rc = 0;
255 	struct hello_context_t hello_context = {};
256 
257 	/* Set default values in opts structure. */
258 	spdk_app_opts_init(&opts);
259 	opts.name = "hello_bdev";
260 	opts.config_file = "bdev.conf";
261 
262 	/*
263 	 * The user can provide the config file and bdev name at run time.
264 	 * For example, to use Malloc0 in file bdev.conf run with params
265 	 * ./hello_bdev -c bdev.conf -b Malloc0
266 	 * To use passthru bdev PT0 run with params
267 	 * ./hello_bdev -c bdev.conf -b PT0
268 	 * If none of the parameters are provide the application will use the
269 	 * default parameters(-c bdev.conf -b Malloc0).
270 	 */
271 	if ((rc = spdk_app_parse_args(argc, argv, &opts, "b:", NULL, hello_bdev_parse_arg,
272 				      hello_bdev_usage)) != SPDK_APP_PARSE_ARGS_SUCCESS) {
273 		exit(rc);
274 	}
275 	hello_context.bdev_name = g_bdev_name;
276 
277 	/*
278 	 * spdk_app_start() will block running hello_start() until
279 	 * spdk_app_stop() is called by someone (not simply when
280 	 * hello_start() returns), or if an error occurs during
281 	 * spdk_app_start() before hello_start() runs.
282 	 */
283 	rc = spdk_app_start(&opts, hello_start, &hello_context, NULL);
284 	if (rc) {
285 		SPDK_ERRLOG("ERROR starting application\n");
286 	}
287 
288 	/* When the app stops, free up memory that we allocated. */
289 	spdk_dma_free(hello_context.buff);
290 
291 	/* Gracefully close out all of the SPDK subsystems. */
292 	spdk_app_fini();
293 	return rc;
294 }
295