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!
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
new file mode 100644
index 0000000..161e9aa
--- /dev/null
+++ b/drivers/md/linear.c
@@ -0,0 +1,343 @@
+/*
+ linear.c : Multiple Devices driver for Linux
+ Copyright (C) 1994-96 Marc ZYNGIER
+ <zyngier@ufr-info-p7.ibp.fr> or
+ <maz@gloups.fdn.fr>
+
+ Linear mode 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/md.h>
+#include <linux/slab.h>
+#include <linux/raid/linear.h>
+
+#define MAJOR_NR MD_MAJOR
+#define MD_DRIVER
+#define MD_PERSONALITY
+
+/*
+ * find which device holds a particular offset
+ */
+static inline dev_info_t *which_dev(mddev_t *mddev, sector_t sector)
+{
+ dev_info_t *hash;
+ linear_conf_t *conf = mddev_to_conf(mddev);
+ sector_t block = sector >> 1;
+
+ /*
+ * sector_div(a,b) returns the remainer and sets a to a/b
+ */
+ (void)sector_div(block, conf->smallest->size);
+ hash = conf->hash_table[block];
+
+ while ((sector>>1) >= (hash->size + hash->offset))
+ hash++;
+ return hash;
+}
+
+/**
+ * linear_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 take at this offset
+ */
+static int linear_mergeable_bvec(request_queue_t *q, struct bio *bio, struct bio_vec *biovec)
+{
+ mddev_t *mddev = q->queuedata;
+ dev_info_t *dev0;
+ unsigned long maxsectors, bio_sectors = bio->bi_size >> 9;
+ sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
+
+ dev0 = which_dev(mddev, sector);
+ maxsectors = (dev0->size << 1) - (sector - (dev0->offset<<1));
+
+ if (maxsectors < bio_sectors)
+ maxsectors = 0;
+ else
+ maxsectors -= bio_sectors;
+
+ if (maxsectors <= (PAGE_SIZE >> 9 ) && bio_sectors == 0)
+ return biovec->bv_len;
+ /* The bytes available at this offset could be really big,
+ * so we cap at 2^31 to avoid overflow */
+ if (maxsectors > (1 << (31-9)))
+ return 1<<31;
+ return maxsectors << 9;
+}
+
+static void linear_unplug(request_queue_t *q)
+{
+ mddev_t *mddev = q->queuedata;
+ linear_conf_t *conf = mddev_to_conf(mddev);
+ int i;
+
+ for (i=0; i < mddev->raid_disks; i++) {
+ request_queue_t *r_queue = bdev_get_queue(conf->disks[i].rdev->bdev);
+ if (r_queue->unplug_fn)
+ r_queue->unplug_fn(r_queue);
+ }
+}
+
+static int linear_issue_flush(request_queue_t *q, struct gendisk *disk,
+ sector_t *error_sector)
+{
+ mddev_t *mddev = q->queuedata;
+ linear_conf_t *conf = mddev_to_conf(mddev);
+ int i, ret = 0;
+
+ for (i=0; i < mddev->raid_disks && ret == 0; i++) {
+ struct block_device *bdev = conf->disks[i].rdev->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 linear_run (mddev_t *mddev)
+{
+ linear_conf_t *conf;
+ dev_info_t **table;
+ mdk_rdev_t *rdev;
+ int i, nb_zone, cnt;
+ sector_t start;
+ sector_t curr_offset;
+ struct list_head *tmp;
+
+ conf = kmalloc (sizeof (*conf) + mddev->raid_disks*sizeof(dev_info_t),
+ GFP_KERNEL);
+ if (!conf)
+ goto out;
+ memset(conf, 0, sizeof(*conf) + mddev->raid_disks*sizeof(dev_info_t));
+ mddev->private = conf;
+
+ /*
+ * Find the smallest device.
+ */
+
+ conf->smallest = NULL;
+ cnt = 0;
+ mddev->array_size = 0;
+
+ ITERATE_RDEV(mddev,rdev,tmp) {
+ int j = rdev->raid_disk;
+ dev_info_t *disk = conf->disks + j;
+
+ if (j < 0 || j > mddev->raid_disks || disk->rdev) {
+ printk("linear: disk numbering problem. Aborting!\n");
+ goto out;
+ }
+
+ disk->rdev = rdev;
+
+ blk_queue_stack_limits(mddev->queue,
+ rdev->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 (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
+ mddev->queue->max_sectors > (PAGE_SIZE>>9))
+ blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
+
+ disk->size = rdev->size;
+ mddev->array_size += rdev->size;
+
+ if (!conf->smallest || (disk->size < conf->smallest->size))
+ conf->smallest = disk;
+ cnt++;
+ }
+ if (cnt != mddev->raid_disks) {
+ printk("linear: not enough drives present. Aborting!\n");
+ goto out;
+ }
+
+ /*
+ * This code was restructured to work around a gcc-2.95.3 internal
+ * compiler error. Alter it with care.
+ */
+ {
+ sector_t sz;
+ unsigned round;
+ unsigned long base;
+
+ sz = mddev->array_size;
+ base = conf->smallest->size;
+ round = sector_div(sz, base);
+ nb_zone = conf->nr_zones = sz + (round ? 1 : 0);
+ }
+
+ conf->hash_table = kmalloc (sizeof (dev_info_t*) * nb_zone,
+ GFP_KERNEL);
+ if (!conf->hash_table)
+ goto out;
+
+ /*
+ * Here we generate the linear hash table
+ */
+ table = conf->hash_table;
+ start = 0;
+ curr_offset = 0;
+ for (i = 0; i < cnt; i++) {
+ dev_info_t *disk = conf->disks + i;
+
+ disk->offset = curr_offset;
+ curr_offset += disk->size;
+
+ /* 'curr_offset' is the end of this disk
+ * 'start' is the start of table
+ */
+ while (start < curr_offset) {
+ *table++ = disk;
+ start += conf->smallest->size;
+ }
+ }
+ if (table-conf->hash_table != nb_zone)
+ BUG();
+
+ blk_queue_merge_bvec(mddev->queue, linear_mergeable_bvec);
+ mddev->queue->unplug_fn = linear_unplug;
+ mddev->queue->issue_flush_fn = linear_issue_flush;
+ return 0;
+
+out:
+ if (conf)
+ kfree(conf);
+ return 1;
+}
+
+static int linear_stop (mddev_t *mddev)
+{
+ linear_conf_t *conf = mddev_to_conf(mddev);
+
+ blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
+ kfree(conf->hash_table);
+ kfree(conf);
+
+ return 0;
+}
+
+static int linear_make_request (request_queue_t *q, struct bio *bio)
+{
+ mddev_t *mddev = q->queuedata;
+ dev_info_t *tmp_dev;
+ sector_t block;
+
+ 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));
+ }
+
+ tmp_dev = which_dev(mddev, bio->bi_sector);
+ block = bio->bi_sector >> 1;
+
+ if (unlikely(block >= (tmp_dev->size + tmp_dev->offset)
+ || block < tmp_dev->offset)) {
+ char b[BDEVNAME_SIZE];
+
+ printk("linear_make_request: Block %llu out of bounds on "
+ "dev %s size %llu offset %llu\n",
+ (unsigned long long)block,
+ bdevname(tmp_dev->rdev->bdev, b),
+ (unsigned long long)tmp_dev->size,
+ (unsigned long long)tmp_dev->offset);
+ bio_io_error(bio, bio->bi_size);
+ return 0;
+ }
+ if (unlikely(bio->bi_sector + (bio->bi_size >> 9) >
+ (tmp_dev->offset + tmp_dev->size)<<1)) {
+ /* This bio crosses a device boundary, so we have to
+ * split it.
+ */
+ struct bio_pair *bp;
+ bp = bio_split(bio, bio_split_pool,
+ (bio->bi_sector + (bio->bi_size >> 9) -
+ (tmp_dev->offset + tmp_dev->size))<<1);
+ if (linear_make_request(q, &bp->bio1))
+ generic_make_request(&bp->bio1);
+ if (linear_make_request(q, &bp->bio2))
+ generic_make_request(&bp->bio2);
+ bio_pair_release(bp);
+ return 0;
+ }
+
+ bio->bi_bdev = tmp_dev->rdev->bdev;
+ bio->bi_sector = bio->bi_sector - (tmp_dev->offset << 1) + tmp_dev->rdev->data_offset;
+
+ return 1;
+}
+
+static void linear_status (struct seq_file *seq, mddev_t *mddev)
+{
+
+#undef MD_DEBUG
+#ifdef MD_DEBUG
+ int j;
+ linear_conf_t *conf = mddev_to_conf(mddev);
+ sector_t s = 0;
+
+ seq_printf(seq, " ");
+ for (j = 0; j < conf->nr_zones; j++)
+ {
+ char b[BDEVNAME_SIZE];
+ s += conf->smallest_size;
+ seq_printf(seq, "[%s",
+ bdevname(conf->hash_table[j][0].rdev->bdev,b));
+
+ while (s > conf->hash_table[j][0].offset +
+ conf->hash_table[j][0].size)
+ seq_printf(seq, "/%s] ",
+ bdevname(conf->hash_table[j][1].rdev->bdev,b));
+ else
+ seq_printf(seq, "] ");
+ }
+ seq_printf(seq, "\n");
+#endif
+ seq_printf(seq, " %dk rounding", mddev->chunk_size/1024);
+}
+
+
+static mdk_personality_t linear_personality=
+{
+ .name = "linear",
+ .owner = THIS_MODULE,
+ .make_request = linear_make_request,
+ .run = linear_run,
+ .stop = linear_stop,
+ .status = linear_status,
+};
+
+static int __init linear_init (void)
+{
+ return register_md_personality (LINEAR, &linear_personality);
+}
+
+static void linear_exit (void)
+{
+ unregister_md_personality (LINEAR);
+}
+
+
+module_init(linear_init);
+module_exit(linear_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("md-personality-1"); /* LINEAR */