linux_dsm_epyc7002/drivers/md/linear.c
NeilBrown 5aa61f427e md: split detach operation out from ->stop.
Each md personality has a 'stop' operation which does two
things:
 1/ it finalizes some aspects of the array to ensure nothing
    is accessing the ->private data
 2/ it frees the ->private data.

All the steps in '1' can apply to all arrays and so can be
performed in common code.

This is useful as in the case where we change the personality which
manages an array (in level_store()), it would be helpful to do
step 1 early, and step 2 later.

So split the 'step 1' functionality out into a new mddev_detach().

Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-04 08:35:52 +11:00

364 lines
8.7 KiB
C

/*
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 = 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 mddev *mddev,
struct bvec_merge_data *bvm,
struct bio_vec *biovec)
{
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;
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));
}
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(struct mddev *mddev, int bits)
{
struct linear_conf *conf;
int i, ret = 0;
conf = 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);
}
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) {
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 (blk_queue_discard(bdev_get_queue(rdev->bdev)))
discard_supported = true;
}
if (cnt != raid_disks) {
printk(KERN_ERR "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;
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;
mddev_suspend(mddev);
oldconf = mddev->private;
mddev->raid_disks++;
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(oldconf);
return 0;
}
static int linear_stop (struct mddev *mddev)
{
struct linear_conf *conf = mddev->private;
kfree(conf);
mddev->private = NULL;
return 0;
}
static void linear_make_request(struct mddev *mddev, struct bio *bio)
{
char b[BDEVNAME_SIZE];
struct dev_info *tmp_dev;
struct bio *split;
sector_t start_sector, end_sector, data_offset;
if (unlikely(bio->bi_rw & REQ_FLUSH)) {
md_flush_request(mddev, bio);
return;
}
do {
tmp_dev = which_dev(mddev, bio->bi_iter.bi_sector);
start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;
end_sector = tmp_dev->end_sector;
data_offset = tmp_dev->rdev->data_offset;
bio->bi_bdev = tmp_dev->rdev->bdev;
if (unlikely(bio->bi_iter.bi_sector >= end_sector ||
bio->bi_iter.bi_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.
*/
split = bio_split(bio, end_sector -
bio->bi_iter.bi_sector,
GFP_NOIO, fs_bio_set);
bio_chain(split, bio);
} else {
split = bio;
}
split->bi_iter.bi_sector = split->bi_iter.bi_sector -
start_sector + data_offset;
if (unlikely((split->bi_rw & REQ_DISCARD) &&
!blk_queue_discard(bdev_get_queue(split->bi_bdev)))) {
/* Just ignore it */
bio_endio(split, 0);
} else
generic_make_request(split);
} while (split != bio);
return;
out_of_bounds:
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_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);
}
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,
.stop = linear_stop,
.status = linear_status,
.hot_add_disk = linear_add,
.size = linear_size,
.quiesce = linear_quiesce,
.congested = linear_congested,
.mergeable_bvec = linear_mergeable_bvec,
};
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");