+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- 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.
-
-*/
-
-#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;
-}
-
-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;
-
- conf = kzalloc(struct_size(conf, disks, raid_disks), GFP_KERNEL);
- if (!conf)
- return NULL;
-
- /*
- * 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;
-
- 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 (cnt != raid_disks) {
- pr_warn("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));
-
- 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.
- */
- 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_and_notify(mddev->gendisk, mddev->array_sectors);
- 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)
-{
- 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(is_rdev_broken(tmp_dev->rdev))) {
- md_error(mddev, tmp_dev->rdev);
- bio_io_error(bio);
- return true;
- }
-
- 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);
- submit_bio_noacct(bio);
- bio = split;
- }
-
- md_account_bio(mddev, &bio);
- 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) &&
- !bdev_max_discard_sectors(bio->bi_bdev))) {
- /* Just ignore it */
- bio_endio(bio);
- } else {
- if (mddev->gendisk)
- trace_block_bio_remap(bio, disk_devt(mddev->gendisk),
- bio_sector);
- mddev_check_write_zeroes(mddev, bio);
- submit_bio_noacct(bio);
- }
- return true;
-
-out_of_bounds:
- pr_err("md/linear:%s: make_request: Sector %llu out of bounds on dev %pg: %llu sectors, offset %llu\n",
- mdname(mddev),
- (unsigned long long)bio->bi_iter.bi_sector,
- tmp_dev->rdev->bdev,
- (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_error(struct mddev *mddev, struct md_rdev *rdev)
-{
- if (!test_and_set_bit(MD_BROKEN, &mddev->flags)) {
- char *md_name = mdname(mddev);
-
- pr_crit("md/linear%s: Disk failure on %pg detected, failing array.\n",
- md_name, rdev->bdev);
- }
-}
-
-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,
- .error_handler = linear_error,
-};
-
-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 (deprecated)");
-MODULE_ALIAS("md-personality-1"); /* LINEAR - deprecated*/
-MODULE_ALIAS("md-linear");
-MODULE_ALIAS("md-level--1");
projects / thirdparty / kernel / linux.git / commitdiff
