md: rename some drivers/md/ files to have an "md-" prefix
Motivated by the desire to illiminate the imprecise nature of
DM-specific patches being unnecessarily sent to both the MD maintainer
and mailing-list. Which is born out of the fact that DM files also
reside in drivers/md/
Now all MD-specific files in drivers/md/ start with either "raid" or
"md-" and the MAINTAINERS file has been updated accordingly.
Shaohua: don't change module name
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
diff --git a/drivers/md/md-linear.c b/drivers/md/md-linear.c
new file mode 100644
index 0000000..773fc70
--- /dev/null
+++ b/drivers/md/md-linear.c
@@ -0,0 +1,348 @@
+/*
+ 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 <trace/events/block.h>
+#include "md.h"
+#include "md-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 = 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;
+}
+
+/*
+ * In linear_congested() conf->raid_disks is used as a copy of
+ * mddev->raid_disks to iterate conf->disks[], because conf->raid_disks
+ * and conf->disks[] are created in linear_conf(), they are always
+ * consitent with each other, but mddev->raid_disks does not.
+ */
+static int linear_congested(struct mddev *mddev, int bits)
+{
+ struct linear_conf *conf;
+ int i, ret = 0;
+
+ rcu_read_lock();
+ conf = rcu_dereference(mddev->private);
+
+ for (i = 0; i < conf->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;
+
+ conf = mddev->private;
+ WARN_ONCE(sectors || raid_disks,
+ "%s does not support generic reshape\n", __func__);
+ array_sectors = conf->array_sectors;
+
+ 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;
+ bool discard_supported = false;
+
+ 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) {
+ pr_warn("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 (blk_queue_discard(bdev_get_queue(rdev->bdev)))
+ discard_supported = true;
+ }
+ if (cnt != raid_disks) {
+ pr_warn("md/linear:%s: not enough drives present. Aborting!\n",
+ mdname(mddev));
+ goto out;
+ }
+
+ if (!discard_supported)
+ queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
+ else
+ queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
+
+ /*
+ * 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;
+
+ /*
+ * conf->raid_disks is copy of mddev->raid_disks. The reason to
+ * keep a copy of mddev->raid_disks in struct linear_conf is,
+ * mddev->raid_disks may not be consistent with pointers number of
+ * conf->disks[] when it is updated in linear_add() and used to
+ * iterate old conf->disks[] earray in linear_congested().
+ * Here conf->raid_disks is always consitent with number of
+ * pointers in conf->disks[] array, and mddev->private is updated
+ * with rcu_assign_pointer() in linear_addr(), such race can be
+ * avoided.
+ */
+ conf->raid_disks = raid_disks;
+
+ 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));
+
+ 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;
+
+ /* newconf->raid_disks already keeps a copy of * the increased
+ * value of mddev->raid_disks, WARN_ONCE() is just used to make
+ * sure of this. It is possible that oldconf is still referenced
+ * in linear_congested(), therefore kfree_rcu() is used to free
+ * oldconf until no one uses it anymore.
+ */
+ mddev_suspend(mddev);
+ oldconf = rcu_dereference_protected(mddev->private,
+ lockdep_is_held(&mddev->reconfig_mutex));
+ mddev->raid_disks++;
+ WARN_ONCE(mddev->raid_disks != newconf->raid_disks,
+ "copied raid_disks doesn't match 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);
+ mddev_resume(mddev);
+ revalidate_disk(mddev->gendisk);
+ kfree_rcu(oldconf, rcu);
+ return 0;
+}
+
+static void linear_free(struct mddev *mddev, void *priv)
+{
+ struct linear_conf *conf = priv;
+
+ kfree(conf);
+}
+
+static bool linear_make_request(struct mddev *mddev, struct bio *bio)
+{
+ char b[BDEVNAME_SIZE];
+ struct dev_info *tmp_dev;
+ sector_t start_sector, end_sector, data_offset;
+ sector_t bio_sector = bio->bi_iter.bi_sector;
+
+ if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
+ md_flush_request(mddev, bio);
+ return true;
+ }
+
+ tmp_dev = which_dev(mddev, bio_sector);
+ start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;
+ end_sector = tmp_dev->end_sector;
+ data_offset = tmp_dev->rdev->data_offset;
+
+ if (unlikely(bio_sector >= end_sector ||
+ bio_sector < start_sector))
+ goto out_of_bounds;
+
+ if (unlikely(bio_end_sector(bio) > end_sector)) {
+ /* This bio crosses a device boundary, so we have to split it */
+ struct bio *split = bio_split(bio, end_sector - bio_sector,
+ GFP_NOIO, mddev->bio_set);
+ bio_chain(split, bio);
+ generic_make_request(bio);
+ bio = split;
+ }
+
+ bio_set_dev(bio, tmp_dev->rdev->bdev);
+ bio->bi_iter.bi_sector = bio->bi_iter.bi_sector -
+ start_sector + data_offset;
+
+ if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
+ !blk_queue_discard(bio->bi_disk->queue))) {
+ /* Just ignore it */
+ bio_endio(bio);
+ } else {
+ if (mddev->gendisk)
+ trace_block_bio_remap(bio->bi_disk->queue,
+ bio, disk_devt(mddev->gendisk),
+ bio_sector);
+ mddev_check_writesame(mddev, bio);
+ mddev_check_write_zeroes(mddev, bio);
+ generic_make_request(bio);
+ }
+ return true;
+
+out_of_bounds:
+ pr_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_iter.bi_sector,
+ bdevname(tmp_dev->rdev->bdev, b),
+ (unsigned long long)tmp_dev->rdev->sectors,
+ (unsigned long long)start_sector);
+ bio_io_error(bio);
+ return true;
+}
+
+static void linear_status (struct seq_file *seq, struct mddev *mddev)
+{
+ seq_printf(seq, " %dk rounding", mddev->chunk_sectors / 2);
+}
+
+static void linear_quiesce(struct mddev *mddev, int state)
+{
+}
+
+static struct md_personality linear_personality =
+{
+ .name = "linear",
+ .level = LEVEL_LINEAR,
+ .owner = THIS_MODULE,
+ .make_request = linear_make_request,
+ .run = linear_run,
+ .free = linear_free,
+ .status = linear_status,
+ .hot_add_disk = linear_add,
+ .size = linear_size,
+ .quiesce = linear_quiesce,
+ .congested = linear_congested,
+};
+
+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");