ath5k: Add Spur filter support on newer chips
[linux-2.6] / drivers / md / raid0.c
1 /*
2    raid0.c : Multiple Devices driver for Linux
3              Copyright (C) 1994-96 Marc ZYNGIER
4              <zyngier@ufr-info-p7.ibp.fr> or
5              <maz@gloups.fdn.fr>
6              Copyright (C) 1999, 2000 Ingo Molnar, Red Hat
7
8
9    RAID-0 management functions.
10
11    This program is free software; you can redistribute it and/or modify
12    it under the terms of the GNU General Public License as published by
13    the Free Software Foundation; either version 2, or (at your option)
14    any later version.
15    
16    You should have received a copy of the GNU General Public License
17    (for example /usr/src/linux/COPYING); if not, write to the Free
18    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  
19 */
20
21 #include <linux/blkdev.h>
22 #include <linux/seq_file.h>
23 #include "md.h"
24 #include "raid0.h"
25
26 static void raid0_unplug(struct request_queue *q)
27 {
28         mddev_t *mddev = q->queuedata;
29         raid0_conf_t *conf = mddev_to_conf(mddev);
30         mdk_rdev_t **devlist = conf->strip_zone[0].dev;
31         int i;
32
33         for (i=0; i<mddev->raid_disks; i++) {
34                 struct request_queue *r_queue = bdev_get_queue(devlist[i]->bdev);
35
36                 blk_unplug(r_queue);
37         }
38 }
39
40 static int raid0_congested(void *data, int bits)
41 {
42         mddev_t *mddev = data;
43         raid0_conf_t *conf = mddev_to_conf(mddev);
44         mdk_rdev_t **devlist = conf->strip_zone[0].dev;
45         int i, ret = 0;
46
47         for (i = 0; i < mddev->raid_disks && !ret ; i++) {
48                 struct request_queue *q = bdev_get_queue(devlist[i]->bdev);
49
50                 ret |= bdi_congested(&q->backing_dev_info, bits);
51         }
52         return ret;
53 }
54
55
56 static int create_strip_zones (mddev_t *mddev)
57 {
58         int i, c, j;
59         sector_t current_start, curr_zone_start;
60         sector_t min_spacing;
61         raid0_conf_t *conf = mddev_to_conf(mddev);
62         mdk_rdev_t *smallest, *rdev1, *rdev2, *rdev;
63         struct strip_zone *zone;
64         int cnt;
65         char b[BDEVNAME_SIZE];
66  
67         /*
68          * The number of 'same size groups'
69          */
70         conf->nr_strip_zones = 0;
71  
72         list_for_each_entry(rdev1, &mddev->disks, same_set) {
73                 printk(KERN_INFO "raid0: looking at %s\n",
74                         bdevname(rdev1->bdev,b));
75                 c = 0;
76                 list_for_each_entry(rdev2, &mddev->disks, same_set) {
77                         printk(KERN_INFO "raid0:   comparing %s(%llu)",
78                                bdevname(rdev1->bdev,b),
79                                (unsigned long long)rdev1->sectors);
80                         printk(KERN_INFO " with %s(%llu)\n",
81                                bdevname(rdev2->bdev,b),
82                                (unsigned long long)rdev2->sectors);
83                         if (rdev2 == rdev1) {
84                                 printk(KERN_INFO "raid0:   END\n");
85                                 break;
86                         }
87                         if (rdev2->sectors == rdev1->sectors) {
88                                 /*
89                                  * Not unique, don't count it as a new
90                                  * group
91                                  */
92                                 printk(KERN_INFO "raid0:   EQUAL\n");
93                                 c = 1;
94                                 break;
95                         }
96                         printk(KERN_INFO "raid0:   NOT EQUAL\n");
97                 }
98                 if (!c) {
99                         printk(KERN_INFO "raid0:   ==> UNIQUE\n");
100                         conf->nr_strip_zones++;
101                         printk(KERN_INFO "raid0: %d zones\n",
102                                 conf->nr_strip_zones);
103                 }
104         }
105         printk(KERN_INFO "raid0: FINAL %d zones\n", conf->nr_strip_zones);
106
107         conf->strip_zone = kzalloc(sizeof(struct strip_zone)*
108                                 conf->nr_strip_zones, GFP_KERNEL);
109         if (!conf->strip_zone)
110                 return 1;
111         conf->devlist = kzalloc(sizeof(mdk_rdev_t*)*
112                                 conf->nr_strip_zones*mddev->raid_disks,
113                                 GFP_KERNEL);
114         if (!conf->devlist)
115                 return 1;
116
117         /* The first zone must contain all devices, so here we check that
118          * there is a proper alignment of slots to devices and find them all
119          */
120         zone = &conf->strip_zone[0];
121         cnt = 0;
122         smallest = NULL;
123         zone->dev = conf->devlist;
124         list_for_each_entry(rdev1, &mddev->disks, same_set) {
125                 int j = rdev1->raid_disk;
126
127                 if (j < 0 || j >= mddev->raid_disks) {
128                         printk(KERN_ERR "raid0: bad disk number %d - "
129                                 "aborting!\n", j);
130                         goto abort;
131                 }
132                 if (zone->dev[j]) {
133                         printk(KERN_ERR "raid0: multiple devices for %d - "
134                                 "aborting!\n", j);
135                         goto abort;
136                 }
137                 zone->dev[j] = rdev1;
138
139                 blk_queue_stack_limits(mddev->queue,
140                                        rdev1->bdev->bd_disk->queue);
141                 /* as we don't honour merge_bvec_fn, we must never risk
142                  * violating it, so limit ->max_sector to one PAGE, as
143                  * a one page request is never in violation.
144                  */
145
146                 if (rdev1->bdev->bd_disk->queue->merge_bvec_fn &&
147                     mddev->queue->max_sectors > (PAGE_SIZE>>9))
148                         blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
149
150                 if (!smallest || (rdev1->sectors < smallest->sectors))
151                         smallest = rdev1;
152                 cnt++;
153         }
154         if (cnt != mddev->raid_disks) {
155                 printk(KERN_ERR "raid0: too few disks (%d of %d) - "
156                         "aborting!\n", cnt, mddev->raid_disks);
157                 goto abort;
158         }
159         zone->nb_dev = cnt;
160         zone->sectors = smallest->sectors * cnt;
161         zone->zone_start = 0;
162
163         current_start = smallest->sectors;
164         curr_zone_start = zone->sectors;
165
166         /* now do the other zones */
167         for (i = 1; i < conf->nr_strip_zones; i++)
168         {
169                 zone = conf->strip_zone + i;
170                 zone->dev = conf->strip_zone[i-1].dev + mddev->raid_disks;
171
172                 printk(KERN_INFO "raid0: zone %d\n", i);
173                 zone->dev_start = current_start;
174                 smallest = NULL;
175                 c = 0;
176
177                 for (j=0; j<cnt; j++) {
178                         char b[BDEVNAME_SIZE];
179                         rdev = conf->strip_zone[0].dev[j];
180                         printk(KERN_INFO "raid0: checking %s ...",
181                                 bdevname(rdev->bdev, b));
182                         if (rdev->sectors <= current_start) {
183                                 printk(KERN_INFO " nope.\n");
184                                 continue;
185                         }
186                         printk(KERN_INFO " contained as device %d\n", c);
187                         zone->dev[c] = rdev;
188                         c++;
189                         if (!smallest || rdev->sectors < smallest->sectors) {
190                                 smallest = rdev;
191                                 printk(KERN_INFO "  (%llu) is smallest!.\n",
192                                         (unsigned long long)rdev->sectors);
193                         }
194                 }
195
196                 zone->nb_dev = c;
197                 zone->sectors = (smallest->sectors - current_start) * c;
198                 printk(KERN_INFO "raid0: zone->nb_dev: %d, sectors: %llu\n",
199                         zone->nb_dev, (unsigned long long)zone->sectors);
200
201                 zone->zone_start = curr_zone_start;
202                 curr_zone_start += zone->sectors;
203
204                 current_start = smallest->sectors;
205                 printk(KERN_INFO "raid0: current zone start: %llu\n",
206                         (unsigned long long)current_start);
207         }
208
209         /* Now find appropriate hash spacing.
210          * We want a number which causes most hash entries to cover
211          * at most two strips, but the hash table must be at most
212          * 1 PAGE.  We choose the smallest strip, or contiguous collection
213          * of strips, that has big enough size.  We never consider the last
214          * strip though as it's size has no bearing on the efficacy of the hash
215          * table.
216          */
217         conf->spacing = curr_zone_start;
218         min_spacing = curr_zone_start;
219         sector_div(min_spacing, PAGE_SIZE/sizeof(struct strip_zone*));
220         for (i=0; i < conf->nr_strip_zones-1; i++) {
221                 sector_t s = 0;
222                 for (j = i; j < conf->nr_strip_zones - 1 &&
223                                 s < min_spacing; j++)
224                         s += conf->strip_zone[j].sectors;
225                 if (s >= min_spacing && s < conf->spacing)
226                         conf->spacing = s;
227         }
228
229         mddev->queue->unplug_fn = raid0_unplug;
230
231         mddev->queue->backing_dev_info.congested_fn = raid0_congested;
232         mddev->queue->backing_dev_info.congested_data = mddev;
233
234         printk(KERN_INFO "raid0: done.\n");
235         return 0;
236  abort:
237         return 1;
238 }
239
240 /**
241  *      raid0_mergeable_bvec -- tell bio layer if a two requests can be merged
242  *      @q: request queue
243  *      @bvm: properties of new bio
244  *      @biovec: the request that could be merged to it.
245  *
246  *      Return amount of bytes we can accept at this offset
247  */
248 static int raid0_mergeable_bvec(struct request_queue *q,
249                                 struct bvec_merge_data *bvm,
250                                 struct bio_vec *biovec)
251 {
252         mddev_t *mddev = q->queuedata;
253         sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
254         int max;
255         unsigned int chunk_sectors = mddev->chunk_size >> 9;
256         unsigned int bio_sectors = bvm->bi_size >> 9;
257
258         max =  (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
259         if (max < 0) max = 0; /* bio_add cannot handle a negative return */
260         if (max <= biovec->bv_len && bio_sectors == 0)
261                 return biovec->bv_len;
262         else 
263                 return max;
264 }
265
266 static sector_t raid0_size(mddev_t *mddev, sector_t sectors, int raid_disks)
267 {
268         sector_t array_sectors = 0;
269         mdk_rdev_t *rdev;
270
271         WARN_ONCE(sectors || raid_disks,
272                   "%s does not support generic reshape\n", __func__);
273
274         list_for_each_entry(rdev, &mddev->disks, same_set)
275                 array_sectors += rdev->sectors;
276
277         return array_sectors;
278 }
279
280 static int raid0_run (mddev_t *mddev)
281 {
282         unsigned  cur=0, i=0, nb_zone;
283         s64 sectors;
284         raid0_conf_t *conf;
285
286         if (mddev->chunk_size == 0) {
287                 printk(KERN_ERR "md/raid0: non-zero chunk size required.\n");
288                 return -EINVAL;
289         }
290         printk(KERN_INFO "%s: setting max_sectors to %d, segment boundary to %d\n",
291                mdname(mddev),
292                mddev->chunk_size >> 9,
293                (mddev->chunk_size>>1)-1);
294         blk_queue_max_sectors(mddev->queue, mddev->chunk_size >> 9);
295         blk_queue_segment_boundary(mddev->queue, (mddev->chunk_size>>1) - 1);
296         mddev->queue->queue_lock = &mddev->queue->__queue_lock;
297
298         conf = kmalloc(sizeof (raid0_conf_t), GFP_KERNEL);
299         if (!conf)
300                 goto out;
301         mddev->private = (void *)conf;
302  
303         conf->strip_zone = NULL;
304         conf->devlist = NULL;
305         if (create_strip_zones (mddev)) 
306                 goto out_free_conf;
307
308         /* calculate array device size */
309         md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
310
311         printk(KERN_INFO "raid0 : md_size is %llu sectors.\n",
312                 (unsigned long long)mddev->array_sectors);
313         printk(KERN_INFO "raid0 : conf->spacing is %llu sectors.\n",
314                 (unsigned long long)conf->spacing);
315         {
316                 sector_t s = raid0_size(mddev, 0, 0);
317                 sector_t space = conf->spacing;
318                 int round;
319                 conf->sector_shift = 0;
320                 if (sizeof(sector_t) > sizeof(u32)) {
321                         /*shift down space and s so that sector_div will work */
322                         while (space > (sector_t) (~(u32)0)) {
323                                 s >>= 1;
324                                 space >>= 1;
325                                 s += 1; /* force round-up */
326                                 conf->sector_shift++;
327                         }
328                 }
329                 round = sector_div(s, (u32)space) ? 1 : 0;
330                 nb_zone = s + round;
331         }
332         printk(KERN_INFO "raid0 : nb_zone is %d.\n", nb_zone);
333
334         printk(KERN_INFO "raid0 : Allocating %zu bytes for hash.\n",
335                                 nb_zone*sizeof(struct strip_zone*));
336         conf->hash_table = kmalloc (sizeof (struct strip_zone *)*nb_zone, GFP_KERNEL);
337         if (!conf->hash_table)
338                 goto out_free_conf;
339         sectors = conf->strip_zone[cur].sectors;
340
341         conf->hash_table[0] = conf->strip_zone + cur;
342         for (i=1; i< nb_zone; i++) {
343                 while (sectors <= conf->spacing) {
344                         cur++;
345                         sectors += conf->strip_zone[cur].sectors;
346                 }
347                 sectors -= conf->spacing;
348                 conf->hash_table[i] = conf->strip_zone + cur;
349         }
350         if (conf->sector_shift) {
351                 conf->spacing >>= conf->sector_shift;
352                 /* round spacing up so when we divide by it, we
353                  * err on the side of too-low, which is safest
354                  */
355                 conf->spacing++;
356         }
357
358         /* calculate the max read-ahead size.
359          * For read-ahead of large files to be effective, we need to
360          * readahead at least twice a whole stripe. i.e. number of devices
361          * multiplied by chunk size times 2.
362          * If an individual device has an ra_pages greater than the
363          * chunk size, then we will not drive that device as hard as it
364          * wants.  We consider this a configuration error: a larger
365          * chunksize should be used in that case.
366          */
367         {
368                 int stripe = mddev->raid_disks * mddev->chunk_size / PAGE_SIZE;
369                 if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
370                         mddev->queue->backing_dev_info.ra_pages = 2* stripe;
371         }
372
373
374         blk_queue_merge_bvec(mddev->queue, raid0_mergeable_bvec);
375         return 0;
376
377 out_free_conf:
378         kfree(conf->strip_zone);
379         kfree(conf->devlist);
380         kfree(conf);
381         mddev->private = NULL;
382 out:
383         return -ENOMEM;
384 }
385
386 static int raid0_stop (mddev_t *mddev)
387 {
388         raid0_conf_t *conf = mddev_to_conf(mddev);
389
390         blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
391         kfree(conf->hash_table);
392         conf->hash_table = NULL;
393         kfree(conf->strip_zone);
394         conf->strip_zone = NULL;
395         kfree(conf);
396         mddev->private = NULL;
397
398         return 0;
399 }
400
401 static int raid0_make_request (struct request_queue *q, struct bio *bio)
402 {
403         mddev_t *mddev = q->queuedata;
404         unsigned int sect_in_chunk, chunksect_bits, chunk_sects;
405         raid0_conf_t *conf = mddev_to_conf(mddev);
406         struct strip_zone *zone;
407         mdk_rdev_t *tmp_dev;
408         sector_t chunk;
409         sector_t sector, rsect;
410         const int rw = bio_data_dir(bio);
411         int cpu;
412
413         if (unlikely(bio_barrier(bio))) {
414                 bio_endio(bio, -EOPNOTSUPP);
415                 return 0;
416         }
417
418         cpu = part_stat_lock();
419         part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
420         part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
421                       bio_sectors(bio));
422         part_stat_unlock();
423
424         chunk_sects = mddev->chunk_size >> 9;
425         chunksect_bits = ffz(~chunk_sects);
426         sector = bio->bi_sector;
427
428         if (unlikely(chunk_sects < (bio->bi_sector & (chunk_sects - 1)) + (bio->bi_size >> 9))) {
429                 struct bio_pair *bp;
430                 /* Sanity check -- queue functions should prevent this happening */
431                 if (bio->bi_vcnt != 1 ||
432                     bio->bi_idx != 0)
433                         goto bad_map;
434                 /* This is a one page bio that upper layers
435                  * refuse to split for us, so we need to split it.
436                  */
437                 bp = bio_split(bio, chunk_sects - (bio->bi_sector & (chunk_sects - 1)));
438                 if (raid0_make_request(q, &bp->bio1))
439                         generic_make_request(&bp->bio1);
440                 if (raid0_make_request(q, &bp->bio2))
441                         generic_make_request(&bp->bio2);
442
443                 bio_pair_release(bp);
444                 return 0;
445         }
446  
447
448         {
449                 sector_t x = sector >> conf->sector_shift;
450                 sector_div(x, (u32)conf->spacing);
451                 zone = conf->hash_table[x];
452         }
453
454         while (sector >= zone->zone_start + zone->sectors)
455                 zone++;
456
457         sect_in_chunk = bio->bi_sector & (chunk_sects - 1);
458
459
460         {
461                 sector_t x = (sector - zone->zone_start) >> chunksect_bits;
462
463                 sector_div(x, zone->nb_dev);
464                 chunk = x;
465
466                 x = sector >> chunksect_bits;
467                 tmp_dev = zone->dev[sector_div(x, zone->nb_dev)];
468         }
469         rsect = (chunk << chunksect_bits) + zone->dev_start + sect_in_chunk;
470  
471         bio->bi_bdev = tmp_dev->bdev;
472         bio->bi_sector = rsect + tmp_dev->data_offset;
473
474         /*
475          * Let the main block layer submit the IO and resolve recursion:
476          */
477         return 1;
478
479 bad_map:
480         printk("raid0_make_request bug: can't convert block across chunks"
481                 " or bigger than %dk %llu %d\n", chunk_sects / 2,
482                 (unsigned long long)bio->bi_sector, bio->bi_size >> 10);
483
484         bio_io_error(bio);
485         return 0;
486 }
487
488 static void raid0_status (struct seq_file *seq, mddev_t *mddev)
489 {
490 #undef MD_DEBUG
491 #ifdef MD_DEBUG
492         int j, k, h;
493         char b[BDEVNAME_SIZE];
494         raid0_conf_t *conf = mddev_to_conf(mddev);
495
496         h = 0;
497         for (j = 0; j < conf->nr_strip_zones; j++) {
498                 seq_printf(seq, "      z%d", j);
499                 if (conf->hash_table[h] == conf->strip_zone+j)
500                         seq_printf(seq, "(h%d)", h++);
501                 seq_printf(seq, "=[");
502                 for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
503                         seq_printf(seq, "%s/", bdevname(
504                                 conf->strip_zone[j].dev[k]->bdev,b));
505
506                 seq_printf(seq, "] zs=%d ds=%d s=%d\n",
507                                 conf->strip_zone[j].zone_start,
508                                 conf->strip_zone[j].dev_start,
509                                 conf->strip_zone[j].sectors);
510         }
511 #endif
512         seq_printf(seq, " %dk chunks", mddev->chunk_size/1024);
513         return;
514 }
515
516 static struct mdk_personality raid0_personality=
517 {
518         .name           = "raid0",
519         .level          = 0,
520         .owner          = THIS_MODULE,
521         .make_request   = raid0_make_request,
522         .run            = raid0_run,
523         .stop           = raid0_stop,
524         .status         = raid0_status,
525         .size           = raid0_size,
526 };
527
528 static int __init raid0_init (void)
529 {
530         return register_md_personality (&raid0_personality);
531 }
532
533 static void raid0_exit (void)
534 {
535         unregister_md_personality (&raid0_personality);
536 }
537
538 module_init(raid0_init);
539 module_exit(raid0_exit);
540 MODULE_LICENSE("GPL");
541 MODULE_ALIAS("md-personality-2"); /* RAID0 */
542 MODULE_ALIAS("md-raid0");
543 MODULE_ALIAS("md-level-0");