[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/drivers/md/linear.c b/ap/os/linux/linux-3.4.x/drivers/md/linear.c
new file mode 100644
index 0000000..fa211d8
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/md/linear.c
@@ -0,0 +1,369 @@
+/*
+ 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/blkdev.h>
+#include <linux/raid/md_u.h>
+#include <linux/seq_file.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include "md.h"
+#include "linear.h"
+
+/*
+ * find which device holds a particular offset
+ */
+static inline struct dev_info *which_dev(struct mddev *mddev, sector_t sector)
+{
+ int lo, mid, hi;
+ struct linear_conf *conf;
+
+ lo = 0;
+ hi = mddev->raid_disks - 1;
+ conf = rcu_dereference(mddev->private);
+
+ /*
+ * Binary Search
+ */
+
+ while (hi > lo) {
+
+ mid = (hi + lo) / 2;
+ if (sector < conf->disks[mid].end_sector)
+ hi = mid;
+ else
+ lo = mid + 1;
+ }
+
+ return conf->disks + lo;
+}
+
+/**
+ * linear_mergeable_bvec -- tell bio layer if two requests can be merged
+ * @q: request queue
+ * @bvm: properties of new bio
+ * @biovec: the request that could be merged to it.
+ *
+ * Return amount of bytes we can take at this offset
+ */
+static int linear_mergeable_bvec(struct request_queue *q,
+ struct bvec_merge_data *bvm,
+ struct bio_vec *biovec)
+{
+ struct mddev *mddev = q->queuedata;
+ struct dev_info *dev0;
+ unsigned long maxsectors, bio_sectors = bvm->bi_size >> 9;
+ sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
+ int maxbytes = biovec->bv_len;
+ struct request_queue *subq;
+
+ rcu_read_lock();
+ dev0 = which_dev(mddev, sector);
+ maxsectors = dev0->end_sector - sector;
+ subq = bdev_get_queue(dev0->rdev->bdev);
+ if (subq->merge_bvec_fn) {
+ bvm->bi_bdev = dev0->rdev->bdev;
+ bvm->bi_sector -= dev0->end_sector - dev0->rdev->sectors;
+ maxbytes = min(maxbytes, subq->merge_bvec_fn(subq, bvm,
+ biovec));
+ }
+ rcu_read_unlock();
+
+ if (maxsectors < bio_sectors)
+ maxsectors = 0;
+ else
+ maxsectors -= bio_sectors;
+
+ if (maxsectors <= (PAGE_SIZE >> 9 ) && bio_sectors == 0)
+ return maxbytes;
+
+ if (maxsectors > (maxbytes >> 9))
+ return maxbytes;
+ else
+ return maxsectors << 9;
+}
+
+static int linear_congested(void *data, int bits)
+{
+ struct mddev *mddev = data;
+ struct linear_conf *conf;
+ int i, ret = 0;
+
+ if (mddev_congested(mddev, bits))
+ return 1;
+
+ rcu_read_lock();
+ conf = rcu_dereference(mddev->private);
+
+ for (i = 0; i < mddev->raid_disks && !ret ; i++) {
+ struct request_queue *q = bdev_get_queue(conf->disks[i].rdev->bdev);
+ ret |= bdi_congested(&q->backing_dev_info, bits);
+ }
+
+ rcu_read_unlock();
+ return ret;
+}
+
+static sector_t linear_size(struct mddev *mddev, sector_t sectors, int raid_disks)
+{
+ struct linear_conf *conf;
+ sector_t array_sectors;
+
+ rcu_read_lock();
+ conf = rcu_dereference(mddev->private);
+ WARN_ONCE(sectors || raid_disks,
+ "%s does not support generic reshape\n", __func__);
+ array_sectors = conf->array_sectors;
+ rcu_read_unlock();
+
+ return array_sectors;
+}
+
+static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
+{
+ struct linear_conf *conf;
+ struct md_rdev *rdev;
+ int i, cnt;
+
+ conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(struct dev_info),
+ GFP_KERNEL);
+ if (!conf)
+ return NULL;
+
+ cnt = 0;
+ conf->array_sectors = 0;
+
+ rdev_for_each(rdev, mddev) {
+ int j = rdev->raid_disk;
+ struct dev_info *disk = conf->disks + j;
+ sector_t sectors;
+
+ if (j < 0 || j >= raid_disks || disk->rdev) {
+ printk(KERN_ERR "md/linear:%s: disk numbering problem. Aborting!\n",
+ mdname(mddev));
+ goto out;
+ }
+
+ disk->rdev = rdev;
+ if (mddev->chunk_sectors) {
+ sectors = rdev->sectors;
+ sector_div(sectors, mddev->chunk_sectors);
+ rdev->sectors = sectors * mddev->chunk_sectors;
+ }
+
+ disk_stack_limits(mddev->gendisk, rdev->bdev,
+ rdev->data_offset << 9);
+
+ conf->array_sectors += rdev->sectors;
+ cnt++;
+
+ }
+ if (cnt != raid_disks) {
+ printk(KERN_ERR "md/linear:%s: not enough drives present. Aborting!\n",
+ mdname(mddev));
+ goto out;
+ }
+
+ /*
+ * Here we calculate the device offsets.
+ */
+ conf->disks[0].end_sector = conf->disks[0].rdev->sectors;
+
+ for (i = 1; i < raid_disks; i++)
+ conf->disks[i].end_sector =
+ conf->disks[i-1].end_sector +
+ conf->disks[i].rdev->sectors;
+
+ return conf;
+
+out:
+ kfree(conf);
+ return NULL;
+}
+
+static int linear_run (struct mddev *mddev)
+{
+ struct linear_conf *conf;
+ int ret;
+
+ if (md_check_no_bitmap(mddev))
+ return -EINVAL;
+ conf = linear_conf(mddev, mddev->raid_disks);
+
+ if (!conf)
+ return 1;
+ mddev->private = conf;
+ md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
+
+ blk_queue_merge_bvec(mddev->queue, linear_mergeable_bvec);
+ mddev->queue->backing_dev_info.congested_fn = linear_congested;
+ mddev->queue->backing_dev_info.congested_data = mddev;
+
+ ret = md_integrity_register(mddev);
+ if (ret) {
+ kfree(conf);
+ mddev->private = NULL;
+ }
+ return ret;
+}
+
+static int linear_add(struct mddev *mddev, struct md_rdev *rdev)
+{
+ /* Adding a drive to a linear array allows the array to grow.
+ * It is permitted if the new drive has a matching superblock
+ * already on it, with raid_disk equal to raid_disks.
+ * It is achieved by creating a new linear_private_data structure
+ * and swapping it in in-place of the current one.
+ * The current one is never freed until the array is stopped.
+ * This avoids races.
+ */
+ struct linear_conf *newconf, *oldconf;
+
+ if (rdev->saved_raid_disk != mddev->raid_disks)
+ return -EINVAL;
+
+ rdev->raid_disk = rdev->saved_raid_disk;
+ rdev->saved_raid_disk = -1;
+
+ newconf = linear_conf(mddev,mddev->raid_disks+1);
+
+ if (!newconf)
+ return -ENOMEM;
+
+ oldconf = rcu_dereference(mddev->private);
+ mddev->raid_disks++;
+ rcu_assign_pointer(mddev->private, newconf);
+ md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
+ set_capacity(mddev->gendisk, mddev->array_sectors);
+ revalidate_disk(mddev->gendisk);
+ kfree_rcu(oldconf, rcu);
+ return 0;
+}
+
+static int linear_stop (struct mddev *mddev)
+{
+ struct linear_conf *conf = mddev->private;
+
+ /*
+ * We do not require rcu protection here since
+ * we hold reconfig_mutex for both linear_add and
+ * linear_stop, so they cannot race.
+ * We should make sure any old 'conf's are properly
+ * freed though.
+ */
+ rcu_barrier();
+ blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
+ kfree(conf);
+ mddev->private = NULL;
+
+ return 0;
+}
+
+static void linear_make_request(struct mddev *mddev, struct bio *bio)
+{
+ struct dev_info *tmp_dev;
+ sector_t start_sector;
+
+ if (unlikely(bio->bi_rw & REQ_FLUSH)) {
+ md_flush_request(mddev, bio);
+ return;
+ }
+
+ rcu_read_lock();
+ tmp_dev = which_dev(mddev, bio->bi_sector);
+ start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;
+
+
+ if (unlikely(bio->bi_sector >= (tmp_dev->end_sector)
+ || (bio->bi_sector < start_sector))) {
+ char b[BDEVNAME_SIZE];
+
+ printk(KERN_ERR
+ "md/linear:%s: make_request: Sector %llu out of bounds on "
+ "dev %s: %llu sectors, offset %llu\n",
+ mdname(mddev),
+ (unsigned long long)bio->bi_sector,
+ bdevname(tmp_dev->rdev->bdev, b),
+ (unsigned long long)tmp_dev->rdev->sectors,
+ (unsigned long long)start_sector);
+ rcu_read_unlock();
+ bio_io_error(bio);
+ return;
+ }
+ if (unlikely(bio->bi_sector + (bio->bi_size >> 9) >
+ tmp_dev->end_sector)) {
+ /* This bio crosses a device boundary, so we have to
+ * split it.
+ */
+ struct bio_pair *bp;
+ sector_t end_sector = tmp_dev->end_sector;
+
+ rcu_read_unlock();
+
+ bp = bio_split(bio, end_sector - bio->bi_sector);
+
+ linear_make_request(mddev, &bp->bio1);
+ linear_make_request(mddev, &bp->bio2);
+ bio_pair_release(bp);
+ return;
+ }
+
+ bio->bi_bdev = tmp_dev->rdev->bdev;
+ bio->bi_sector = bio->bi_sector - start_sector
+ + tmp_dev->rdev->data_offset;
+ rcu_read_unlock();
+ generic_make_request(bio);
+}
+
+static void linear_status (struct seq_file *seq, struct mddev *mddev)
+{
+
+ seq_printf(seq, " %dk rounding", mddev->chunk_sectors / 2);
+}
+
+
+static struct md_personality linear_personality =
+{
+ .name = "linear",
+ .level = LEVEL_LINEAR,
+ .owner = THIS_MODULE,
+ .make_request = linear_make_request,
+ .run = linear_run,
+ .stop = linear_stop,
+ .status = linear_status,
+ .hot_add_disk = linear_add,
+ .size = linear_size,
+};
+
+static int __init linear_init (void)
+{
+ return register_md_personality (&linear_personality);
+}
+
+static void linear_exit (void)
+{
+ unregister_md_personality (&linear_personality);
+}
+
+
+module_init(linear_init);
+module_exit(linear_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Linear device concatenation personality for MD");
+MODULE_ALIAS("md-personality-1"); /* LINEAR - deprecated*/
+MODULE_ALIAS("md-linear");
+MODULE_ALIAS("md-level--1");