Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 539 insertions, 0 deletions

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
new file mode 100644
index 000000000000..e7d934eca06f
--- /dev/null
+++ b/drivers/md/raid0.c
@@ -0,0 +1,539 @@
+/*
+   raid0.c : Multiple Devices driver for Linux
+             Copyright (C) 1994-96 Marc ZYNGIER
+	     <zyngier@ufr-info-p7.ibp.fr> or
+	     <maz@gloups.fdn.fr>
+             Copyright (C) 1999, 2000 Ingo Molnar, Red Hat
+
+
+   RAID-0 management functions.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+   
+   You should have received a copy of the GNU General Public License
+   (for example /usr/src/linux/COPYING); if not, write to the Free
+   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  
+*/
+
+#include <linux/module.h>
+#include <linux/raid/raid0.h>
+
+#define MAJOR_NR MD_MAJOR
+#define MD_DRIVER
+#define MD_PERSONALITY
+
+static void raid0_unplug(request_queue_t *q)
+{
+	mddev_t *mddev = q->queuedata;
+	raid0_conf_t *conf = mddev_to_conf(mddev);
+	mdk_rdev_t **devlist = conf->strip_zone[0].dev;
+	int i;
+
+	for (i=0; i<mddev->raid_disks; i++) {
+		request_queue_t *r_queue = bdev_get_queue(devlist[i]->bdev);
+
+		if (r_queue->unplug_fn)
+			r_queue->unplug_fn(r_queue);
+	}
+}
+
+static int raid0_issue_flush(request_queue_t *q, struct gendisk *disk,
+			     sector_t *error_sector)
+{
+	mddev_t *mddev = q->queuedata;
+	raid0_conf_t *conf = mddev_to_conf(mddev);
+	mdk_rdev_t **devlist = conf->strip_zone[0].dev;
+	int i, ret = 0;
+
+	for (i=0; i<mddev->raid_disks && ret == 0; i++) {
+		struct block_device *bdev = devlist[i]->bdev;
+		request_queue_t *r_queue = bdev_get_queue(bdev);
+
+		if (!r_queue->issue_flush_fn)
+			ret = -EOPNOTSUPP;
+		else
+			ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, error_sector);
+	}
+	return ret;
+}
+
+
+static int create_strip_zones (mddev_t *mddev)
+{
+	int i, c, j;
+	sector_t current_offset, curr_zone_offset;
+	sector_t min_spacing;
+	raid0_conf_t *conf = mddev_to_conf(mddev);
+	mdk_rdev_t *smallest, *rdev1, *rdev2, *rdev;
+	struct list_head *tmp1, *tmp2;
+	struct strip_zone *zone;
+	int cnt;
+	char b[BDEVNAME_SIZE];
+ 
+	/*
+	 * The number of 'same size groups'
+	 */
+	conf->nr_strip_zones = 0;
+ 
+	ITERATE_RDEV(mddev,rdev1,tmp1) {
+		printk("raid0: looking at %s\n",
+			bdevname(rdev1->bdev,b));
+		c = 0;
+		ITERATE_RDEV(mddev,rdev2,tmp2) {
+			printk("raid0:   comparing %s(%llu)",
+			       bdevname(rdev1->bdev,b),
+			       (unsigned long long)rdev1->size);
+			printk(" with %s(%llu)\n",
+			       bdevname(rdev2->bdev,b),
+			       (unsigned long long)rdev2->size);
+			if (rdev2 == rdev1) {
+				printk("raid0:   END\n");
+				break;
+			}
+			if (rdev2->size == rdev1->size)
+			{
+				/*
+				 * Not unique, don't count it as a new
+				 * group
+				 */
+				printk("raid0:   EQUAL\n");
+				c = 1;
+				break;
+			}
+			printk("raid0:   NOT EQUAL\n");
+		}
+		if (!c) {
+			printk("raid0:   ==> UNIQUE\n");
+			conf->nr_strip_zones++;
+			printk("raid0: %d zones\n", conf->nr_strip_zones);
+		}
+	}
+	printk("raid0: FINAL %d zones\n", conf->nr_strip_zones);
+
+	conf->strip_zone = kmalloc(sizeof(struct strip_zone)*
+				conf->nr_strip_zones, GFP_KERNEL);
+	if (!conf->strip_zone)
+		return 1;
+	conf->devlist = kmalloc(sizeof(mdk_rdev_t*)*
+				conf->nr_strip_zones*mddev->raid_disks,
+				GFP_KERNEL);
+	if (!conf->devlist)
+		return 1;
+
+	memset(conf->strip_zone, 0,sizeof(struct strip_zone)*
+				   conf->nr_strip_zones);
+	memset(conf->devlist, 0,
+	       sizeof(mdk_rdev_t*) * conf->nr_strip_zones * mddev->raid_disks);
+
+	/* The first zone must contain all devices, so here we check that
+	 * there is a proper alignment of slots to devices and find them all
+	 */
+	zone = &conf->strip_zone[0];
+	cnt = 0;
+	smallest = NULL;
+	zone->dev = conf->devlist;
+	ITERATE_RDEV(mddev, rdev1, tmp1) {
+		int j = rdev1->raid_disk;
+
+		if (j < 0 || j >= mddev->raid_disks) {
+			printk("raid0: bad disk number %d - aborting!\n", j);
+			goto abort;
+		}
+		if (zone->dev[j]) {
+			printk("raid0: multiple devices for %d - aborting!\n",
+				j);
+			goto abort;
+		}
+		zone->dev[j] = rdev1;
+
+		blk_queue_stack_limits(mddev->queue,
+				       rdev1->bdev->bd_disk->queue);
+		/* as we don't honour merge_bvec_fn, we must never risk
+		 * violating it, so limit ->max_sector to one PAGE, as
+		 * a one page request is never in violation.
+		 */
+
+		if (rdev1->bdev->bd_disk->queue->merge_bvec_fn &&
+		    mddev->queue->max_sectors > (PAGE_SIZE>>9))
+			blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
+
+		if (!smallest || (rdev1->size <smallest->size))
+			smallest = rdev1;
+		cnt++;
+	}
+	if (cnt != mddev->raid_disks) {
+		printk("raid0: too few disks (%d of %d) - aborting!\n",
+			cnt, mddev->raid_disks);
+		goto abort;
+	}
+	zone->nb_dev = cnt;
+	zone->size = smallest->size * cnt;
+	zone->zone_offset = 0;
+
+	current_offset = smallest->size;
+	curr_zone_offset = zone->size;
+
+	/* now do the other zones */
+	for (i = 1; i < conf->nr_strip_zones; i++)
+	{
+		zone = conf->strip_zone + i;
+		zone->dev = conf->strip_zone[i-1].dev + mddev->raid_disks;
+
+		printk("raid0: zone %d\n", i);
+		zone->dev_offset = current_offset;
+		smallest = NULL;
+		c = 0;
+
+		for (j=0; j<cnt; j++) {
+			char b[BDEVNAME_SIZE];
+			rdev = conf->strip_zone[0].dev[j];
+			printk("raid0: checking %s ...", bdevname(rdev->bdev,b));
+			if (rdev->size > current_offset)
+			{
+				printk(" contained as device %d\n", c);
+				zone->dev[c] = rdev;
+				c++;
+				if (!smallest || (rdev->size <smallest->size)) {
+					smallest = rdev;
+					printk("  (%llu) is smallest!.\n", 
+						(unsigned long long)rdev->size);
+				}
+			} else
+				printk(" nope.\n");
+		}
+
+		zone->nb_dev = c;
+		zone->size = (smallest->size - current_offset) * c;
+		printk("raid0: zone->nb_dev: %d, size: %llu\n",
+			zone->nb_dev, (unsigned long long)zone->size);
+
+		zone->zone_offset = curr_zone_offset;
+		curr_zone_offset += zone->size;
+
+		current_offset = smallest->size;
+		printk("raid0: current zone offset: %llu\n",
+			(unsigned long long)current_offset);
+	}
+
+	/* Now find appropriate hash spacing.
+	 * We want a number which causes most hash entries to cover
+	 * at most two strips, but the hash table must be at most
+	 * 1 PAGE.  We choose the smallest strip, or contiguous collection
+	 * of strips, that has big enough size.  We never consider the last
+	 * strip though as it's size has no bearing on the efficacy of the hash
+	 * table.
+	 */
+	conf->hash_spacing = curr_zone_offset;
+	min_spacing = curr_zone_offset;
+	sector_div(min_spacing, PAGE_SIZE/sizeof(struct strip_zone*));
+	for (i=0; i < conf->nr_strip_zones-1; i++) {
+		sector_t sz = 0;
+		for (j=i; j<conf->nr_strip_zones-1 &&
+			     sz < min_spacing ; j++)
+			sz += conf->strip_zone[j].size;
+		if (sz >= min_spacing && sz < conf->hash_spacing)
+			conf->hash_spacing = sz;
+	}
+
+	mddev->queue->unplug_fn = raid0_unplug;
+
+	mddev->queue->issue_flush_fn = raid0_issue_flush;
+
+	printk("raid0: done.\n");
+	return 0;
+ abort:
+	return 1;
+}
+
+/**
+ *	raid0_mergeable_bvec -- tell bio layer if a two requests can be merged
+ *	@q: request queue
+ *	@bio: the buffer head that's been built up so far
+ *	@biovec: the request that could be merged to it.
+ *
+ *	Return amount of bytes we can accept at this offset
+ */
+static int raid0_mergeable_bvec(request_queue_t *q, struct bio *bio, struct bio_vec *biovec)
+{
+	mddev_t *mddev = q->queuedata;
+	sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
+	int max;
+	unsigned int chunk_sectors = mddev->chunk_size >> 9;
+	unsigned int bio_sectors = bio->bi_size >> 9;
+
+	max =  (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
+	if (max < 0) max = 0; /* bio_add cannot handle a negative return */
+	if (max <= biovec->bv_len && bio_sectors == 0)
+		return biovec->bv_len;
+	else 
+		return max;
+}
+
+static int raid0_run (mddev_t *mddev)
+{
+	unsigned  cur=0, i=0, nb_zone;
+	s64 size;
+	raid0_conf_t *conf;
+	mdk_rdev_t *rdev;
+	struct list_head *tmp;
+
+	printk("%s: setting max_sectors to %d, segment boundary to %d\n",
+	       mdname(mddev),
+	       mddev->chunk_size >> 9,
+	       (mddev->chunk_size>>1)-1);
+	blk_queue_max_sectors(mddev->queue, mddev->chunk_size >> 9);
+	blk_queue_segment_boundary(mddev->queue, (mddev->chunk_size>>1) - 1);
+
+	conf = kmalloc(sizeof (raid0_conf_t), GFP_KERNEL);
+	if (!conf)
+		goto out;
+	mddev->private = (void *)conf;
+ 
+	conf->strip_zone = NULL;
+	conf->devlist = NULL;
+	if (create_strip_zones (mddev)) 
+		goto out_free_conf;
+
+	/* calculate array device size */
+	mddev->array_size = 0;
+	ITERATE_RDEV(mddev,rdev,tmp)
+		mddev->array_size += rdev->size;
+
+	printk("raid0 : md_size is %llu blocks.\n", 
+		(unsigned long long)mddev->array_size);
+	printk("raid0 : conf->hash_spacing is %llu blocks.\n",
+		(unsigned long long)conf->hash_spacing);
+	{
+#if __GNUC__ < 3
+		volatile
+#endif
+		sector_t s = mddev->array_size;
+		sector_t space = conf->hash_spacing;
+		int round;
+		conf->preshift = 0;
+		if (sizeof(sector_t) > sizeof(unsigned long)) {
+			/*shift down space and s so that sector_div will work */
+			while (space > (sector_t) (~(unsigned long)0)) {
+				s >>= 1;
+				space >>= 1;
+				s += 1; /* force round-up */
+				conf->preshift++;
+			}
+		}
+		round = sector_div(s, (unsigned long)space) ? 1 : 0;
+		nb_zone = s + round;
+	}
+	printk("raid0 : nb_zone is %d.\n", nb_zone);
+
+	printk("raid0 : Allocating %Zd bytes for hash.\n",
+				nb_zone*sizeof(struct strip_zone*));
+	conf->hash_table = kmalloc (sizeof (struct strip_zone *)*nb_zone, GFP_KERNEL);
+	if (!conf->hash_table)
+		goto out_free_conf;
+	size = conf->strip_zone[cur].size;
+
+	for (i=0; i< nb_zone; i++) {
+		conf->hash_table[i] = conf->strip_zone + cur;
+		while (size <= conf->hash_spacing) {
+			cur++;
+			size += conf->strip_zone[cur].size;
+		}
+		size -= conf->hash_spacing;
+	}
+	if (conf->preshift) {
+		conf->hash_spacing >>= conf->preshift;
+		/* round hash_spacing up so when we divide by it, we
+		 * err on the side of too-low, which is safest
+		 */
+		conf->hash_spacing++;
+	}
+
+	/* calculate the max read-ahead size.
+	 * For read-ahead of large files to be effective, we need to
+	 * readahead at least twice a whole stripe. i.e. number of devices
+	 * multiplied by chunk size times 2.
+	 * If an individual device has an ra_pages greater than the
+	 * chunk size, then we will not drive that device as hard as it
+	 * wants.  We consider this a configuration error: a larger
+	 * chunksize should be used in that case.
+	 */
+	{
+		int stripe = mddev->raid_disks * mddev->chunk_size / PAGE_CACHE_SIZE;
+		if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
+			mddev->queue->backing_dev_info.ra_pages = 2* stripe;
+	}
+
+
+	blk_queue_merge_bvec(mddev->queue, raid0_mergeable_bvec);
+	return 0;
+
+out_free_conf:
+	if (conf->strip_zone)
+		kfree(conf->strip_zone);
+	if (conf->devlist)
+		kfree (conf->devlist);
+	kfree(conf);
+	mddev->private = NULL;
+out:
+	return 1;
+}
+
+static int raid0_stop (mddev_t *mddev)
+{
+	raid0_conf_t *conf = mddev_to_conf(mddev);
+
+	blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
+	kfree (conf->hash_table);
+	conf->hash_table = NULL;
+	kfree (conf->strip_zone);
+	conf->strip_zone = NULL;
+	kfree (conf);
+	mddev->private = NULL;
+
+	return 0;
+}
+
+static int raid0_make_request (request_queue_t *q, struct bio *bio)
+{
+	mddev_t *mddev = q->queuedata;
+	unsigned int sect_in_chunk, chunksize_bits,  chunk_size, chunk_sects;
+	raid0_conf_t *conf = mddev_to_conf(mddev);
+	struct strip_zone *zone;
+	mdk_rdev_t *tmp_dev;
+	unsigned long chunk;
+	sector_t block, rsect;
+
+	if (bio_data_dir(bio)==WRITE) {
+		disk_stat_inc(mddev->gendisk, writes);
+		disk_stat_add(mddev->gendisk, write_sectors, bio_sectors(bio));
+	} else {
+		disk_stat_inc(mddev->gendisk, reads);
+		disk_stat_add(mddev->gendisk, read_sectors, bio_sectors(bio));
+	}
+
+	chunk_size = mddev->chunk_size >> 10;
+	chunk_sects = mddev->chunk_size >> 9;
+	chunksize_bits = ffz(~chunk_size);
+	block = bio->bi_sector >> 1;
+	
+
+	if (unlikely(chunk_sects < (bio->bi_sector & (chunk_sects - 1)) + (bio->bi_size >> 9))) {
+		struct bio_pair *bp;
+		/* Sanity check -- queue functions should prevent this happening */
+		if (bio->bi_vcnt != 1 ||
+		    bio->bi_idx != 0)
+			goto bad_map;
+		/* This is a one page bio that upper layers
+		 * refuse to split for us, so we need to split it.
+		 */
+		bp = bio_split(bio, bio_split_pool, chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
+		if (raid0_make_request(q, &bp->bio1))
+			generic_make_request(&bp->bio1);
+		if (raid0_make_request(q, &bp->bio2))
+			generic_make_request(&bp->bio2);
+
+		bio_pair_release(bp);
+		return 0;
+	}
+ 
+
+	{
+#if __GNUC__ < 3
+		volatile
+#endif
+		sector_t x = block >> conf->preshift;
+		sector_div(x, (unsigned long)conf->hash_spacing);
+		zone = conf->hash_table[x];
+	}
+ 
+	while (block >= (zone->zone_offset + zone->size)) 
+		zone++;
+    
+	sect_in_chunk = bio->bi_sector & ((chunk_size<<1) -1);
+
+
+	{
+		sector_t x =  (block - zone->zone_offset) >> chunksize_bits;
+
+		sector_div(x, zone->nb_dev);
+		chunk = x;
+		BUG_ON(x != (sector_t)chunk);
+
+		x = block >> chunksize_bits;
+		tmp_dev = zone->dev[sector_div(x, zone->nb_dev)];
+	}
+	rsect = (((chunk << chunksize_bits) + zone->dev_offset)<<1)
+		+ sect_in_chunk;
+ 
+	bio->bi_bdev = tmp_dev->bdev;
+	bio->bi_sector = rsect + tmp_dev->data_offset;
+
+	/*
+	 * Let the main block layer submit the IO and resolve recursion:
+	 */
+	return 1;
+
+bad_map:
+	printk("raid0_make_request bug: can't convert block across chunks"
+		" or bigger than %dk %llu %d\n", chunk_size, 
+		(unsigned long long)bio->bi_sector, bio->bi_size >> 10);
+
+	bio_io_error(bio, bio->bi_size);
+	return 0;
+}
+			   
+static void raid0_status (struct seq_file *seq, mddev_t *mddev)
+{
+#undef MD_DEBUG
+#ifdef MD_DEBUG
+	int j, k, h;
+	char b[BDEVNAME_SIZE];
+	raid0_conf_t *conf = mddev_to_conf(mddev);
+  
+	h = 0;
+	for (j = 0; j < conf->nr_strip_zones; j++) {
+		seq_printf(seq, "      z%d", j);
+		if (conf->hash_table[h] == conf->strip_zone+j)
+			seq_printf("(h%d)", h++);
+		seq_printf(seq, "=[");
+		for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
+			seq_printf (seq, "%s/", bdevname(
+				conf->strip_zone[j].dev[k]->bdev,b));
+
+		seq_printf (seq, "] zo=%d do=%d s=%d\n",
+				conf->strip_zone[j].zone_offset,
+				conf->strip_zone[j].dev_offset,
+				conf->strip_zone[j].size);
+	}
+#endif
+	seq_printf(seq, " %dk chunks", mddev->chunk_size/1024);
+	return;
+}
+
+static mdk_personality_t raid0_personality=
+{
+	.name		= "raid0",
+	.owner		= THIS_MODULE,
+	.make_request	= raid0_make_request,
+	.run		= raid0_run,
+	.stop		= raid0_stop,
+	.status		= raid0_status,
+};
+
+static int __init raid0_init (void)
+{
+	return register_md_personality (RAID0, &raid0_personality);
+}
+
+static void raid0_exit (void)
+{
+	unregister_md_personality (RAID0);
+}
+
+module_init(raid0_init);
+module_exit(raid0_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("md-personality-2"); /* RAID0 */