xref: /netbsd-src/sys/dev/dm/dm_target_stripe.c (revision 6dffe8d42bd46273f674d7ab834e7be9b1af990e)
1 /*$NetBSD: dm_target_stripe.c,v 1.6 2009/06/05 19:56:40 haad Exp $*/
2 
3 /*
4  * Copyright (c) 2009 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Adam Hamsik.
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  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * This file implements initial version of device-mapper stripe target.
34  */
35 #include <sys/types.h>
36 #include <sys/param.h>
37 
38 #include <sys/buf.h>
39 #include <sys/kmem.h>
40 #include <sys/vnode.h>
41 
42 #include "dm.h"
43 #include "netbsd-dm.h"
44 
45 #ifdef DM_TARGET_MODULE
46 /*
47  * Every target can be compiled directly to dm driver or as a
48  * separate module this part of target is used for loading targets
49  * to dm driver.
50  * Target can be unloaded from kernel only if there are no users of
51  * it e.g. there are no devices which uses that target.
52  */
53 #include <sys/kernel.h>
54 #include <sys/module.h>
55 
56 MODULE(MODULE_CLASS_MISC, dm_target_stripe, NULL);
57 
58 static int
59 dm_target_stripe_modcmd(modcmd_t cmd, void *arg)
60 {
61 	dm_target_t *dmt;
62 	int r;
63 	dmt = NULL;
64 
65 	switch (cmd) {
66 	case MODULE_CMD_INIT:
67 		if ((dmt = dm_target_lookup("stripe")) != NULL) {
68 			dm_target_unbusy(dmt);
69 			return EEXIST;
70 		}
71 
72 		dmt = dm_target_alloc("stripe");
73 
74 		dmt->version[0] = 1;
75 		dmt->version[1] = 0;
76 		dmt->version[2] = 0;
77 		strlcpy(dmt->name, "stripe", DM_MAX_TYPE_NAME);
78 		dmt->init = &dm_target_stripe_init;
79 		dmt->status = &dm_target_stripe_status;
80 		dmt->strategy = &dm_target_stripe_strategy;
81 		dmt->deps = &dm_target_stripe_deps;
82 		dmt->destroy = &dm_target_stripe_destroy;
83 		dmt->upcall = &dm_target_stripe_upcall;
84 
85 		r = dm_target_insert(dmt);
86 
87 		break;
88 
89 	case MODULE_CMD_FINI:
90 		r = dm_target_rem("stripe");
91 		break;
92 
93 	case MODULE_CMD_STAT:
94 		return ENOTTY;
95 
96 	default:
97 		return ENOTTY;
98 	}
99 
100 	return r;
101 }
102 
103 #endif
104 
105 /*
106  * Init function called from dm_table_load_ioctl.
107  * Example line sent to dm from lvm tools when using striped target.
108  * start length striped #stripes chunk_size device1 offset1 ... deviceN offsetN
109  * 0 65536 striped 2 512 /dev/hda 0 /dev/hdb 0
110  */
111 int
112 dm_target_stripe_init(dm_dev_t *dmv, void **target_config, prop_dictionary_t dict)
113 {
114 	dm_target_stripe_config_t *tsc;
115 	prop_array_t dev_array;
116 	prop_dictionary_t dev_dict1, dev_dict2;
117 
118 	uint64_t stripes, chunk_size, offset1, offset2;
119 	const char *device1, *device2;
120 
121 	if (prop_dictionary_get_uint64(dict, DM_TARGET_STRIPE_STRIPES,
122 		&stripes) == false)
123 		return EINVAL;
124 
125 	if (prop_dictionary_get_uint64(dict, DM_TARGET_STRIPE_CHUNKSIZE,
126 		&chunk_size) == false)
127 		return EINVAL;
128 
129 	dev_array = prop_dictionary_get(dict, DM_TARGET_STRIPE_DEVARRAY);
130 
131 	/* XXX Support for more than 2 devices */
132 	dev_dict1 = prop_array_get(dev_array, 0);
133 	dev_dict2 = prop_array_get(dev_array, 1);
134 
135 	if(dev_dict2 == NULL || dev_dict1 == NULL)
136 		return EINVAL;
137 
138         prop_dictionary_get_cstring_nocopy(dev_dict1, DM_TARGET_STRIPE_DEVICE, &device1);
139 	prop_dictionary_get_uint64(dev_dict1, DM_TARGET_STRIPE_OFFSET, &offset1);
140 	prop_dictionary_get_cstring_nocopy(dev_dict2, DM_TARGET_STRIPE_DEVICE, &device2);
141 	prop_dictionary_get_uint64(dev_dict2, DM_TARGET_STRIPE_OFFSET, &offset2);
142 
143 	aprint_debug("Stripe target init function called!!\n");
144 
145 	aprint_debug("Stripe target chunk size %"PRIu64" number of stripes %"PRIu64"\n", chunk_size, stripes);
146 	aprint_debug("Stripe target device name %s -- offset %"PRIu64"\n", device1, offset1);
147 	aprint_debug("Stripe target device name %s -- offset %"PRIu64"\n", device2, offset2);
148 
149 	if (stripes > MAX_STRIPES)
150 		return ENOTSUP;
151 
152 	if ((tsc = kmem_alloc(sizeof(dm_target_stripe_config_t), KM_NOSLEEP))
153 	    == NULL)
154 		return ENOMEM;
155 
156 	/* Insert dmp to global pdev list */
157 	if ((tsc->stripe_devs[0].pdev = dm_pdev_insert(device1)) == NULL)
158 		return ENOENT;
159 
160 	/* Insert dmp to global pdev list */
161 	if ((tsc->stripe_devs[1].pdev = dm_pdev_insert(device2)) == NULL)
162 		return ENOENT;
163 
164 	tsc->stripe_devs[0].offset = offset1;
165 	tsc->stripe_devs[1].offset = offset2;
166 
167 	/* Save length of param string */
168 	tsc->params_len = DM_MAX_PARAMS_SIZE;
169 	tsc->stripe_chunksize = chunk_size;
170 	tsc->stripe_num = (uint8_t)stripes;
171 
172 	*target_config = tsc;
173 
174 	dmv->dev_type = DM_STRIPE_DEV;
175 
176 	return 0;
177 }
178 
179 /* Status routine called to get params string. */
180 char *
181 dm_target_stripe_status(void *target_config)
182 {
183 	dm_target_stripe_config_t *tsc;
184 	char *params;
185 
186 	tsc = target_config;
187 
188 	if ((params = kmem_alloc(tsc->params_len, KM_NOSLEEP)) == NULL)
189 		return NULL;
190 
191 	snprintf(params, tsc->params_len, "%d %"PRIu64" %s %"PRIu64" %s %"PRIu64,
192 	    tsc->stripe_num, tsc->stripe_chunksize,
193 	    tsc->stripe_devs[0].pdev->name, tsc->stripe_devs[0].offset,
194 	    tsc->stripe_devs[1].pdev->name, tsc->stripe_devs[1].offset);
195 
196 	return params;
197 }
198 
199 /* Strategy routine called from dm_strategy. */
200 int
201 dm_target_stripe_strategy(dm_table_entry_t *table_en, struct buf *bp)
202 {
203 	dm_target_stripe_config_t *tsc;
204 	struct buf *nestbuf;
205 	uint64_t blkno, blkoff;
206 	uint64_t stripe, stripe_blknr;
207 	uint32_t stripe_off, stripe_rest, num_blks, issue_blks;
208 	int stripe_devnr;
209 
210 	tsc = table_en->target_config;
211 	if (tsc == NULL)
212 		return 0;
213 
214 /*	aprint_debug("Stripe target read function called %" PRIu64 "!!\n",
215 	tlc->offset);*/
216 
217 	/* calculate extent of request */
218 	KASSERT(bp->b_resid % DEV_BSIZE == 0);
219 
220 	blkno  = bp->b_blkno;
221 	blkoff = 0;
222 	num_blks = bp->b_resid / DEV_BSIZE;
223 	for (;;) {
224 		/* blockno to strip piece nr */
225 		stripe     = blkno / tsc->stripe_chunksize;
226 		stripe_off = blkno % tsc->stripe_chunksize;
227 
228 		/* where we are inside the strip */
229 		stripe_devnr = stripe % tsc->stripe_num;
230 		stripe_blknr = stripe / tsc->stripe_num;
231 
232 		/* how much is left before we hit a boundary */
233 		stripe_rest = tsc->stripe_chunksize - stripe_off;
234 
235 		/* issue this piece on stripe `stripe' */
236 		issue_blks = MIN(stripe_rest, num_blks);
237 		nestbuf = getiobuf(NULL, true);
238 
239 		nestiobuf_setup(bp, nestbuf, blkoff, issue_blks * DEV_BSIZE);
240 		nestbuf->b_blkno = stripe_blknr * tsc->stripe_chunksize + stripe_off;
241 		nestbuf->b_blkno += tsc->stripe_devs[stripe_devnr].offset;
242 
243 		VOP_STRATEGY(tsc->stripe_devs[stripe_devnr].pdev->pdev_vnode, nestbuf);
244 
245 		blkno    += issue_blks;
246 		blkoff   += issue_blks * DEV_BSIZE;
247 		num_blks -= issue_blks;
248 
249 		if (num_blks <= 0)
250 			break;
251 	}
252 
253 	return 0;
254 }
255 
256 /* Doesn't do anything here. */
257 int
258 dm_target_stripe_destroy(dm_table_entry_t *table_en)
259 {
260 	dm_target_stripe_config_t *tsc;
261 
262 	tsc = table_en->target_config;
263 
264 	if (tsc == NULL)
265 		return 0;
266 
267 	dm_pdev_decr(tsc->stripe_devs[0].pdev);
268 	dm_pdev_decr(tsc->stripe_devs[1].pdev);
269 
270 	/* Unbusy target so we can unload it */
271 	dm_target_unbusy(table_en->target);
272 
273 	kmem_free(tsc, sizeof(dm_target_stripe_config_t));
274 
275 	table_en->target_config = NULL;
276 
277 	return 0;
278 }
279 
280 /* Doesn't not need to do anything here. */
281 int
282 dm_target_stripe_deps(dm_table_entry_t *table_en, prop_array_t prop_array)
283 {
284 	dm_target_stripe_config_t *tsc;
285 	struct vattr va;
286 
287 	int error;
288 
289 	if (table_en->target_config == NULL)
290 		return ENOENT;
291 
292 	tsc = table_en->target_config;
293 
294 	if ((error = VOP_GETATTR(tsc->stripe_devs[0].pdev->pdev_vnode, &va, curlwp->l_cred)) != 0)
295 		return error;
296 
297 	prop_array_add_uint64(prop_array, (uint64_t)va.va_rdev);
298 
299 	if ((error = VOP_GETATTR(tsc->stripe_devs[1].pdev->pdev_vnode, &va, curlwp->l_cred)) != 0)
300 		return error;
301 
302 	prop_array_add_uint64(prop_array, (uint64_t)va.va_rdev);
303 
304 	return 0;
305 }
306 
307 /* Unsupported for this target. */
308 int
309 dm_target_stripe_upcall(dm_table_entry_t *table_en, struct buf *bp)
310 {
311 	return 0;
312 }
313