1/*$NetBSD$*/
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#include <sys/lwp.h>
42
43#include "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
56MODULE(MODULE_CLASS_MISC, dm_target_stripe, NULL);
57
58static int
59dm_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		dmt = dm_target_alloc("stripe");
72
73		dmt->version[0] = 1;
74		dmt->version[1] = 0;
75		dmt->version[2] = 0;
76		strlcpy(dmt->name, "stripe", DM_MAX_TYPE_NAME);
77		dmt->init = &dm_target_stripe_init;
78		dmt->status = &dm_target_stripe_status;
79		dmt->strategy = &dm_target_stripe_strategy;
80		dmt->sync = &dm_target_stripe_sync;
81		dmt->deps = &dm_target_stripe_deps;
82		dmt->destroy = &dm_target_stripe_destroy;
83		dmt->upcall = &dm_target_stripe_upcall;
84		dmt->secsize = &dm_target_stripe_secsize;
85
86		r = dm_target_insert(dmt);
87
88		break;
89
90	case MODULE_CMD_FINI:
91		r = dm_target_rem("stripe");
92		break;
93
94	case MODULE_CMD_STAT:
95		return ENOTTY;
96
97	default:
98		return ENOTTY;
99	}
100
101	return r;
102}
103#endif
104
105/*
106 * Init function called from dm_table_load_ioctl.
107 * DM_STRIPE_DEV_OFFSET should always hold the index of the first device-offset
108 * pair in the parameters.
109 * Example line sent to dm from lvm tools when using striped target.
110 * start length striped #stripes chunk_size device1 offset1 ... deviceN offsetN
111 * 0 65536 striped 2 512 /dev/hda 0 /dev/hdb 0
112 */
113int
114dm_target_stripe_init(dm_dev_t * dmv, void **target_config, char *params)
115{
116	dm_target_linear_config_t *tlc;
117	dm_target_stripe_config_t *tsc;
118	size_t len;
119	char **ap, *argv[10];
120	int strpc, strpi;
121
122	if (params == NULL)
123		return EINVAL;
124
125	len = strlen(params) + 1;
126
127	/*
128	 * Parse a string, containing tokens delimited by white space,
129	 * into an argument vector
130	 */
131	for (ap = argv; ap <= &argv[9] &&
132	    (*ap = strsep(&params, " \t")) != NULL;) {
133		if (**ap != '\0')
134			ap++;
135	}
136
137	printf("Stripe target init function called!!\n");
138
139	printf("Stripe target chunk size %s number of stripes %s\n",
140	    argv[1], argv[0]);
141
142	if ((tsc = kmem_alloc(sizeof(*tsc), KM_NOSLEEP)) == NULL)
143		return ENOMEM;
144
145	/* Initialize linked list for striping devices */
146	TAILQ_INIT(&tsc->stripe_devs);
147
148	/* Save length of param string */
149	tsc->params_len = len;
150	tsc->stripe_chunksize = atoi(argv[1]);
151	tsc->stripe_num = (uint8_t) atoi(argv[0]);
152
153	strpc = DM_STRIPE_DEV_OFFSET + (tsc->stripe_num * 2);
154	for (strpi = DM_STRIPE_DEV_OFFSET; strpi < strpc; strpi += 2) {
155		printf("Stripe target device name %s -- offset %s\n",
156		       argv[strpi], argv[strpi+1]);
157
158		tlc = kmem_alloc(sizeof(*tlc), KM_NOSLEEP);
159		if ((tlc->pdev = dm_pdev_insert(argv[strpi])) == NULL)
160			return ENOENT;
161		tlc->offset = atoi(argv[strpi+1]);
162
163		/* Insert striping device to linked list. */
164		TAILQ_INSERT_TAIL(&tsc->stripe_devs, tlc, entries);
165	}
166
167	*target_config = tsc;
168
169	dmv->dev_type = DM_STRIPE_DEV;
170
171	return 0;
172}
173/* Status routine called to get params string. */
174char *
175dm_target_stripe_status(void *target_config)
176{
177	dm_target_linear_config_t *tlc;
178	dm_target_stripe_config_t *tsc;
179	char *params, *tmp;
180
181	tsc = target_config;
182
183	if ((params = kmem_alloc(DM_MAX_PARAMS_SIZE, KM_SLEEP)) == NULL)
184		return NULL;
185
186	if ((tmp = kmem_alloc(DM_MAX_PARAMS_SIZE, KM_SLEEP)) == NULL)
187		return NULL;
188
189	snprintf(params, DM_MAX_PARAMS_SIZE, "%d %" PRIu64,
190	    tsc->stripe_num, tsc->stripe_chunksize);
191
192	TAILQ_FOREACH(tlc, &tsc->stripe_devs, entries) {
193		snprintf(tmp, DM_MAX_PARAMS_SIZE, " %s %" PRIu64,
194		    tlc->pdev->name, tlc->offset);
195		strcat(params, tmp);
196	}
197
198	kmem_free(tmp, DM_MAX_PARAMS_SIZE);
199
200	return params;
201}
202/* Strategy routine called from dm_strategy. */
203int
204dm_target_stripe_strategy(dm_table_entry_t * table_en, struct buf * bp)
205{
206	dm_target_linear_config_t *tlc;
207	dm_target_stripe_config_t *tsc;
208	struct buf *nestbuf;
209	uint64_t blkno, blkoff;
210	uint64_t stripe, stripe_blknr;
211	uint32_t stripe_off, stripe_rest, num_blks, issue_blks;
212	int i, stripe_devnr;
213
214	tsc = table_en->target_config;
215	if (tsc == NULL)
216		return 0;
217
218/*	printf("Stripe target read function called %" PRIu64 "!!\n",
219	tlc->offset);*/
220
221	/* calculate extent of request */
222	KASSERT(bp->b_resid % DEV_BSIZE == 0);
223
224	blkno = bp->b_blkno;
225	blkoff = 0;
226	num_blks = bp->b_resid / DEV_BSIZE;
227	for (;;) {
228		/* blockno to strip piece nr */
229		stripe = blkno / tsc->stripe_chunksize;
230		stripe_off = blkno % tsc->stripe_chunksize;
231
232		/* where we are inside the strip */
233		stripe_devnr = stripe % tsc->stripe_num;
234		stripe_blknr = stripe / tsc->stripe_num;
235
236		/* how much is left before we hit a boundary */
237		stripe_rest = tsc->stripe_chunksize - stripe_off;
238
239		/* issue this piece on stripe `stripe' */
240		issue_blks = MIN(stripe_rest, num_blks);
241		nestbuf = getiobuf(NULL, true);
242
243		nestiobuf_setup(bp, nestbuf, blkoff, issue_blks * DEV_BSIZE);
244		nestbuf->b_blkno = stripe_blknr * tsc->stripe_chunksize + stripe_off;
245
246		tlc = TAILQ_FIRST(&tsc->stripe_devs);
247		for (i = 0; i < stripe_devnr && tlc != NULL; i++)
248			tlc = TAILQ_NEXT(tlc, entries);
249
250		/* by this point we should have an tlc */
251		KASSERT(tlc != NULL);
252
253		nestbuf->b_blkno += tlc->offset;
254
255		VOP_STRATEGY(tlc->pdev->pdev_vnode, nestbuf);
256
257		blkno += issue_blks;
258		blkoff += issue_blks * DEV_BSIZE;
259		num_blks -= issue_blks;
260
261		if (num_blks <= 0)
262			break;
263	}
264
265	return 0;
266}
267/* Sync underlying disk caches. */
268int
269dm_target_stripe_sync(dm_table_entry_t * table_en)
270{
271	int cmd, err;
272	dm_target_stripe_config_t *tsc;
273	dm_target_linear_config_t *tlc;
274
275	tsc = table_en->target_config;
276
277	err = 0;
278	cmd = 1;
279
280	TAILQ_FOREACH(tlc, &tsc->stripe_devs, entries) {
281		if ((err = VOP_IOCTL(tlc->pdev->pdev_vnode, DIOCCACHESYNC,
282			    &cmd, FREAD|FWRITE, kauth_cred_get())) != 0)
283			return err;
284	}
285
286	return err;
287
288}
289/* Destroy target specific data. */
290int
291dm_target_stripe_destroy(dm_table_entry_t * table_en)
292{
293	dm_target_stripe_config_t *tsc;
294	dm_target_linear_config_t *tlc;
295
296	tsc = table_en->target_config;
297
298	if (tsc == NULL)
299		return 0;
300
301	while ((tlc = TAILQ_FIRST(&tsc->stripe_devs)) != NULL) {
302		TAILQ_REMOVE(&tsc->stripe_devs, tlc, entries);
303		dm_pdev_decr(tlc->pdev);
304		kmem_free(tlc, sizeof(*tlc));
305	}
306
307	/* Unbusy target so we can unload it */
308	dm_target_unbusy(table_en->target);
309
310	kmem_free(tsc, sizeof(*tsc));
311
312	table_en->target_config = NULL;
313
314	return 0;
315}
316/* Doesn't not need to do anything here. */
317int
318dm_target_stripe_deps(dm_table_entry_t * table_en, prop_array_t prop_array)
319{
320	dm_target_stripe_config_t *tsc;
321	dm_target_linear_config_t *tlc;
322	struct vattr va;
323
324	int error;
325
326	if (table_en->target_config == NULL)
327		return ENOENT;
328
329	tsc = table_en->target_config;
330
331	TAILQ_FOREACH(tlc, &tsc->stripe_devs, entries) {
332		vn_lock(tlc->pdev->pdev_vnode, LK_SHARED | LK_RETRY);
333		error = VOP_GETATTR(tlc->pdev->pdev_vnode, &va, curlwp->l_cred);
334		VOP_UNLOCK(tlc->pdev->pdev_vnode);
335		if (error != 0)
336			return error;
337
338		prop_array_add_uint64(prop_array, (uint64_t) va.va_rdev);
339	}
340
341	return 0;
342}
343/* Unsupported for this target. */
344int
345dm_target_stripe_upcall(dm_table_entry_t * table_en, struct buf * bp)
346{
347	return 0;
348}
349/*
350 * Compute physical block size
351 * For a stripe target we chose the maximum sector size of all
352 * stripe devices. For the supported power-of-2 sizes this is equivalent
353 * to the least common multiple.
354 */
355int
356dm_target_stripe_secsize(dm_table_entry_t * table_en, unsigned *secsizep)
357{
358	dm_target_linear_config_t *tlc;
359	dm_target_stripe_config_t *tsc;
360	unsigned secsize;
361
362	secsize = 0;
363
364	tsc = table_en->target_config;
365	if (tsc != NULL) {
366		TAILQ_FOREACH(tlc, &tsc->stripe_devs, entries) {
367			if (secsize < tlc->pdev->pdev_secsize)
368				secsize = tlc->pdev->pdev_secsize;
369		}
370	}
371
372	*secsizep = secsize;
373
374	return 0;
375}
376