lib/clz_tab.c


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// SPDX-License-Identifier: GPL-2.0
const unsigned char __clz_tab[] = {
	0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5,
	    5, 5, 5, 5, 5, 5, 5, 5,
	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
	    6, 6, 6, 6, 6, 6, 6, 6,
	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
	    7, 7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
	    7, 7, 7, 7, 7, 7, 7, 7,
	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
	    8, 8, 8, 8, 8, 8, 8, 8,
	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
	    8, 8, 8, 8, 8, 8, 8, 8,
	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
	    8, 8, 8, 8, 8, 8, 8, 8,
	8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
	    8, 8, 8, 8, 8, 8, 8, 8,
};
/*
   raid0.c : Multiple Devices driver for Linux
	     Copyright (C) 1994-96 Marc ZYNGIER
	     <zyngier@ufr-info-p7.ibp.fr> or
	     <maz@gloups.fdn.fr>
	     Copyright (C) 1999, 2000 Ingo Molnar, Red Hat

   RAID-0 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/seq_file.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <trace/events/block.h>
#include "md.h"
#include "raid0.h"
#include "raid5.h"

#define UNSUPPORTED_MDDEV_FLAGS		\
	((1L << MD_HAS_JOURNAL) |	\
	 (1L << MD_JOURNAL_CLEAN) |	\
	 (1L << MD_FAILFAST_SUPPORTED) |\
	 (1L << MD_HAS_PPL) |		\
	 (1L << MD_HAS_MULTIPLE_PPLS))

static int raid0_congested(struct mddev *mddev, int bits)
{
	struct r0conf *conf = mddev->private;
	struct md_rdev **devlist = conf->devlist;
	int raid_disks = conf->strip_zone[0].nb_dev;
	int i, ret = 0;

	for (i = 0; i < raid_disks && !ret ; i++) {
		struct request_queue *q = bdev_get_queue(devlist[i]->bdev);

		ret |= bdi_congested(q->backing_dev_info, bits);
	}
	return ret;
}

/*
 * inform the user of the raid configuration
*/
static void dump_zones(struct mddev *mddev)
{
	int j, k;
	sector_t zone_size = 0;
	sector_t zone_start = 0;
	char b[BDEVNAME_SIZE];
	struct r0conf *conf = mddev->private;
	int raid_disks = conf->strip_zone[0].nb_dev;
	pr_debug("md: RAID0 configuration for %s - %d zone%s\n",
		 mdname(mddev),
		 conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s");
	for (j = 0; j < conf->nr_strip_zones; j++) {
		char line[200];
		int len = 0;

		for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
			len += snprintf(line+len, 200-len, "%s%s", k?"/":"",
					bdevname(conf->devlist[j*raid_disks
							       + k]->bdev, b));
		pr_debug("md: zone%d=[%s]\n", j, line);

		zone_size  = conf->strip_zone[j].zone_end - zone_start;
		pr_debug("      zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n",
			(unsigned long long)zone_start>>1,
			(unsigned long long)conf->strip_zone[j].dev_start>>1,
			(unsigned long long)zone_size>>1);
		zone_start = conf->strip_zone[j].zone_end;
	}
}

static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
{
	int i, c, err;
	sector_t curr_zone_end, sectors;
	struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev;
	struct strip_zone *zone;
	int cnt;
	char b[BDEVNAME_SIZE];
	char b2[BDEVNAME_SIZE];
	struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
	unsigned short blksize = 512;

	*private_conf = ERR_PTR(-ENOMEM);
	if (!conf)
		return -ENOMEM;
	rdev_for_each(rdev1, mddev) {
		pr_debug("md/raid0:%s: looking at %s\n",
			 mdname(mddev),
			 bdevname(rdev1->bdev, b));
		c = 0;

		/* round size to chunk_size */
		sectors = rdev1->sectors;
		sector_div(sectors, mddev->chunk_sectors);
		rdev1->sectors = sectors * mddev->chunk_sectors;

		blksize = max(blksize, queue_logical_block_size(
				      rdev1->bdev->bd_disk->queue));

		rdev_for_each(rdev2, mddev) {
			pr_debug("md/raid0:%s:   comparing %s(%llu)"
				 " with %s(%llu)\n",
				 mdname(mddev),
				 bdevname(rdev1->bdev,b),
				 (unsigned long long)rdev1->sectors,
				 bdevname(rdev2->bdev,b2),
				 (unsigned long long)rdev2->sectors);
			if (rdev2 == rdev1) {
				pr_debug("md/raid0:%s:   END\n",
					 mdname(mddev));
				break;
			}
			if (rdev2->sectors == rdev1->sectors) {
				/*
				 * Not unique, don't count it as a new
				 * group
				 */
				pr_debug("md/raid0:%s:   EQUAL\n",
					 mdname(mddev));
				c = 1;
				break;
			}
			pr_debug("md/raid0:%s:   NOT EQUAL\n",
				 mdname(mddev));
		}
		if (!c) {
			pr_debug("md/raid0:%s:   ==> UNIQUE\n",
				 mdname(mddev));
			conf->nr_strip_zones++;
			pr_debug("md/raid0:%s: %d zones\n",
				 mdname(mddev), conf->nr_strip_zones);
		}
	}
	pr_debug("md/raid0:%s: FINAL %d zones\n",
		 mdname(mddev), conf->nr_strip_zones);
	/*
	 * now since we have the hard sector sizes, we can make sure
	 * chunk size is a multiple of that sector size
	 */
	if ((mddev->chunk_sectors << 9) % blksize) {
		pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n",
			mdname(mddev),
			mddev->chunk_sectors << 9, blksize);
		err = -EINVAL;
		goto abort;
	}

	err = -ENOMEM;
	conf->strip_zone = kzalloc(sizeof(struct strip_zone