linux/block/blk-zoned.c
Damien Le Moal bf50545696 block: Introduce blk_revalidate_disk_zones()
Drivers exposing zoned block devices have to initialize and maintain
correctness (i.e. revalidate) of the device zone bitmaps attached to
the device request queue (seq_zones_bitmap and seq_zones_wlock).

To simplify coding this, introduce a generic helper function
blk_revalidate_disk_zones() suitable for most (and likely all) cases.
This new function always update the seq_zones_bitmap and seq_zones_wlock
bitmaps as well as the queue nr_zones field when called for a disk
using a request based queue. For a disk using a BIO based queue, only
the number of zones is updated since these queues do not have
schedulers and so do not need the zone bitmaps.

With this change, the zone bitmap initialization code in sd_zbc.c can be
replaced with a call to this function in sd_zbc_read_zones(), which is
called from the disk revalidate block operation method.

A call to blk_revalidate_disk_zones() is also added to the null_blk
driver for devices created with the zoned mode enabled.

Finally, to ensure that zoned devices created with dm-linear or
dm-flakey expose the correct number of zones through sysfs, a call to
blk_revalidate_disk_zones() is added to dm_table_set_restrictions().

The zone bitmaps allocated and initialized with
blk_revalidate_disk_zones() are freed automatically from
__blk_release_queue() using the block internal function
blk_queue_free_zone_bitmaps().

Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-25 11:17:40 -06:00

498 lines
12 KiB
C

/*
* Zoned block device handling
*
* Copyright (c) 2015, Hannes Reinecke
* Copyright (c) 2015, SUSE Linux GmbH
*
* Copyright (c) 2016, Damien Le Moal
* Copyright (c) 2016, Western Digital
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rbtree.h>
#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include "blk.h"
static inline sector_t blk_zone_start(struct request_queue *q,
sector_t sector)
{
sector_t zone_mask = blk_queue_zone_sectors(q) - 1;
return sector & ~zone_mask;
}
/*
* Return true if a request is a write requests that needs zone write locking.
*/
bool blk_req_needs_zone_write_lock(struct request *rq)
{
if (!rq->q->seq_zones_wlock)
return false;
if (blk_rq_is_passthrough(rq))
return false;
switch (req_op(rq)) {
case REQ_OP_WRITE_ZEROES:
case REQ_OP_WRITE_SAME:
case REQ_OP_WRITE:
return blk_rq_zone_is_seq(rq);
default:
return false;
}
}
EXPORT_SYMBOL_GPL(blk_req_needs_zone_write_lock);
void __blk_req_zone_write_lock(struct request *rq)
{
if (WARN_ON_ONCE(test_and_set_bit(blk_rq_zone_no(rq),
rq->q->seq_zones_wlock)))
return;
WARN_ON_ONCE(rq->rq_flags & RQF_ZONE_WRITE_LOCKED);
rq->rq_flags |= RQF_ZONE_WRITE_LOCKED;
}
EXPORT_SYMBOL_GPL(__blk_req_zone_write_lock);
void __blk_req_zone_write_unlock(struct request *rq)
{
rq->rq_flags &= ~RQF_ZONE_WRITE_LOCKED;
if (rq->q->seq_zones_wlock)
WARN_ON_ONCE(!test_and_clear_bit(blk_rq_zone_no(rq),
rq->q->seq_zones_wlock));
}
EXPORT_SYMBOL_GPL(__blk_req_zone_write_unlock);
static inline unsigned int __blkdev_nr_zones(struct request_queue *q,
sector_t nr_sectors)
{
unsigned long zone_sectors = blk_queue_zone_sectors(q);
return (nr_sectors + zone_sectors - 1) >> ilog2(zone_sectors);
}
/**
* blkdev_nr_zones - Get number of zones
* @bdev: Target block device
*
* Description:
* Return the total number of zones of a zoned block device.
* For a regular block device, the number of zones is always 0.
*/
unsigned int blkdev_nr_zones(struct block_device *bdev)
{
struct request_queue *q = bdev_get_queue(bdev);
if (!blk_queue_is_zoned(q))
return 0;
return __blkdev_nr_zones(q, bdev->bd_part->nr_sects);
}
EXPORT_SYMBOL_GPL(blkdev_nr_zones);
/*
* Check that a zone report belongs to this partition, and if yes, fix its start
* sector and write pointer and return true. Return false otherwise.
*/
static bool blkdev_report_zone(struct block_device *bdev, struct blk_zone *rep)
{
sector_t offset = get_start_sect(bdev);
if (rep->start < offset)
return false;
rep->start -= offset;
if (rep->start + rep->len > bdev->bd_part->nr_sects)
return false;
if (rep->type == BLK_ZONE_TYPE_CONVENTIONAL)
rep->wp = rep->start + rep->len;
else
rep->wp -= offset;
return true;
}
static int blk_report_zones(struct gendisk *disk, sector_t sector,
struct blk_zone *zones, unsigned int *nr_zones,
gfp_t gfp_mask)
{
struct request_queue *q = disk->queue;
unsigned int z = 0, n, nrz = *nr_zones;
sector_t capacity = get_capacity(disk);
int ret;
while (z < nrz && sector < capacity) {
n = nrz - z;
ret = disk->fops->report_zones(disk, sector, &zones[z], &n,
gfp_mask);
if (ret)
return ret;
if (!n)
break;
sector += blk_queue_zone_sectors(q) * n;
z += n;
}
WARN_ON(z > *nr_zones);
*nr_zones = z;
return 0;
}
/**
* blkdev_report_zones - Get zones information
* @bdev: Target block device
* @sector: Sector from which to report zones
* @zones: Array of zone structures where to return the zones information
* @nr_zones: Number of zone structures in the zone array
* @gfp_mask: Memory allocation flags (for bio_alloc)
*
* Description:
* Get zone information starting from the zone containing @sector.
* The number of zone information reported may be less than the number
* requested by @nr_zones. The number of zones actually reported is
* returned in @nr_zones.
*/
int blkdev_report_zones(struct block_device *bdev, sector_t sector,
struct blk_zone *zones, unsigned int *nr_zones,
gfp_t gfp_mask)
{
struct request_queue *q = bdev_get_queue(bdev);
unsigned int i, nrz;
int ret;
if (!blk_queue_is_zoned(q))
return -EOPNOTSUPP;
/*
* A block device that advertized itself as zoned must have a
* report_zones method. If it does not have one defined, the device
* driver has a bug. So warn about that.
*/
if (WARN_ON_ONCE(!bdev->bd_disk->fops->report_zones))
return -EOPNOTSUPP;
if (!*nr_zones || sector >= bdev->bd_part->nr_sects) {
*nr_zones = 0;
return 0;
}
nrz = min(*nr_zones,
__blkdev_nr_zones(q, bdev->bd_part->nr_sects - sector));
ret = blk_report_zones(bdev->bd_disk, get_start_sect(bdev) + sector,
zones, &nrz, gfp_mask);
if (ret)
return ret;
for (i = 0; i < nrz; i++) {
if (!blkdev_report_zone(bdev, zones))
break;
zones++;
}
*nr_zones = i;
return 0;
}
EXPORT_SYMBOL_GPL(blkdev_report_zones);
/**
* blkdev_reset_zones - Reset zones write pointer
* @bdev: Target block device
* @sector: Start sector of the first zone to reset
* @nr_sectors: Number of sectors, at least the length of one zone
* @gfp_mask: Memory allocation flags (for bio_alloc)
*
* Description:
* Reset the write pointer of the zones contained in the range
* @sector..@sector+@nr_sectors. Specifying the entire disk sector range
* is valid, but the specified range should not contain conventional zones.
*/
int blkdev_reset_zones(struct block_device *bdev,
sector_t sector, sector_t nr_sectors,
gfp_t gfp_mask)
{
struct request_queue *q = bdev_get_queue(bdev);
sector_t zone_sectors;
sector_t end_sector = sector + nr_sectors;
struct bio *bio = NULL;
struct blk_plug plug;
int ret;
if (!blk_queue_is_zoned(q))
return -EOPNOTSUPP;
if (bdev_read_only(bdev))
return -EPERM;
if (!nr_sectors || end_sector > bdev->bd_part->nr_sects)
/* Out of range */
return -EINVAL;
/* Check alignment (handle eventual smaller last zone) */
zone_sectors = blk_queue_zone_sectors(q);
if (sector & (zone_sectors - 1))
return -EINVAL;
if ((nr_sectors & (zone_sectors - 1)) &&
end_sector != bdev->bd_part->nr_sects)
return -EINVAL;
blk_start_plug(&plug);
while (sector < end_sector) {
bio = blk_next_bio(bio, 0, gfp_mask);
bio->bi_iter.bi_sector = sector;
bio_set_dev(bio, bdev);
bio_set_op_attrs(bio, REQ_OP_ZONE_RESET, 0);
sector += zone_sectors;
/* This may take a while, so be nice to others */
cond_resched();
}
ret = submit_bio_wait(bio);
bio_put(bio);
blk_finish_plug(&plug);
return ret;
}
EXPORT_SYMBOL_GPL(blkdev_reset_zones);
/*
* BLKREPORTZONE ioctl processing.
* Called from blkdev_ioctl.
*/
int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
struct request_queue *q;
struct blk_zone_report rep;
struct blk_zone *zones;
int ret;
if (!argp)
return -EINVAL;
q = bdev_get_queue(bdev);
if (!q)
return -ENXIO;
if (!blk_queue_is_zoned(q))
return -ENOTTY;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (copy_from_user(&rep, argp, sizeof(struct blk_zone_report)))
return -EFAULT;
if (!rep.nr_zones)
return -EINVAL;
rep.nr_zones = min(blkdev_nr_zones(bdev), rep.nr_zones);
zones = kvmalloc_array(rep.nr_zones, sizeof(struct blk_zone),
GFP_KERNEL | __GFP_ZERO);
if (!zones)
return -ENOMEM;
ret = blkdev_report_zones(bdev, rep.sector,
zones, &rep.nr_zones,
GFP_KERNEL);
if (ret)
goto out;
if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report))) {
ret = -EFAULT;
goto out;
}
if (rep.nr_zones) {
if (copy_to_user(argp + sizeof(struct blk_zone_report), zones,
sizeof(struct blk_zone) * rep.nr_zones))
ret = -EFAULT;
}
out:
kvfree(zones);
return ret;
}
/*
* BLKRESETZONE ioctl processing.
* Called from blkdev_ioctl.
*/
int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
struct request_queue *q;
struct blk_zone_range zrange;
if (!argp)
return -EINVAL;
q = bdev_get_queue(bdev);
if (!q)
return -ENXIO;
if (!blk_queue_is_zoned(q))
return -ENOTTY;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (!(mode & FMODE_WRITE))
return -EBADF;
if (copy_from_user(&zrange, argp, sizeof(struct blk_zone_range)))
return -EFAULT;
return blkdev_reset_zones(bdev, zrange.sector, zrange.nr_sectors,
GFP_KERNEL);
}
static inline unsigned long *blk_alloc_zone_bitmap(int node,
unsigned int nr_zones)
{
return kcalloc_node(BITS_TO_LONGS(nr_zones), sizeof(unsigned long),
GFP_NOIO, node);
}
/*
* Allocate an array of struct blk_zone to get nr_zones zone information.
* The allocated array may be smaller than nr_zones.
*/
static struct blk_zone *blk_alloc_zones(int node, unsigned int *nr_zones)
{
size_t size = *nr_zones * sizeof(struct blk_zone);
struct page *page;
int order;
for (order = get_order(size); order > 0; order--) {
page = alloc_pages_node(node, GFP_NOIO | __GFP_ZERO, order);
if (page) {
*nr_zones = min_t(unsigned int, *nr_zones,
(PAGE_SIZE << order) / sizeof(struct blk_zone));
return page_address(page);
}
}
return NULL;
}
void blk_queue_free_zone_bitmaps(struct request_queue *q)
{
kfree(q->seq_zones_bitmap);
q->seq_zones_bitmap = NULL;
kfree(q->seq_zones_wlock);
q->seq_zones_wlock = NULL;
}
/**
* blk_revalidate_disk_zones - (re)allocate and initialize zone bitmaps
* @disk: Target disk
*
* Helper function for low-level device drivers to (re) allocate and initialize
* a disk request queue zone bitmaps. This functions should normally be called
* within the disk ->revalidate method. For BIO based queues, no zone bitmap
* is allocated.
*/
int blk_revalidate_disk_zones(struct gendisk *disk)
{
struct request_queue *q = disk->queue;
unsigned int nr_zones = __blkdev_nr_zones(q, get_capacity(disk));
unsigned long *seq_zones_wlock = NULL, *seq_zones_bitmap = NULL;
unsigned int i, rep_nr_zones = 0, z = 0, nrz;
struct blk_zone *zones = NULL;
sector_t sector = 0;
int ret = 0;
/*
* BIO based queues do not use a scheduler so only q->nr_zones
* needs to be updated so that the sysfs exposed value is correct.
*/
if (!queue_is_rq_based(q)) {
q->nr_zones = nr_zones;
return 0;
}
if (!blk_queue_is_zoned(q) || !nr_zones) {
nr_zones = 0;
goto update;
}
/* Allocate bitmaps */
ret = -ENOMEM;
seq_zones_wlock = blk_alloc_zone_bitmap(q->node, nr_zones);
if (!seq_zones_wlock)
goto out;
seq_zones_bitmap = blk_alloc_zone_bitmap(q->node, nr_zones);
if (!seq_zones_bitmap)
goto out;
/* Get zone information and initialize seq_zones_bitmap */
rep_nr_zones = nr_zones;
zones = blk_alloc_zones(q->node, &rep_nr_zones);
if (!zones)
goto out;
while (z < nr_zones) {
nrz = min(nr_zones - z, rep_nr_zones);
ret = blk_report_zones(disk, sector, zones, &nrz, GFP_NOIO);
if (ret)
goto out;
if (!nrz)
break;
for (i = 0; i < nrz; i++) {
if (zones[i].type != BLK_ZONE_TYPE_CONVENTIONAL)
set_bit(z, seq_zones_bitmap);
z++;
}
sector += nrz * blk_queue_zone_sectors(q);
}
if (WARN_ON(z != nr_zones)) {
ret = -EIO;
goto out;
}
update:
/*
* Install the new bitmaps, making sure the queue is stopped and
* all I/Os are completed (i.e. a scheduler is not referencing the
* bitmaps).
*/
blk_mq_freeze_queue(q);
q->nr_zones = nr_zones;
swap(q->seq_zones_wlock, seq_zones_wlock);
swap(q->seq_zones_bitmap, seq_zones_bitmap);
blk_mq_unfreeze_queue(q);
out:
free_pages((unsigned long)zones,
get_order(rep_nr_zones * sizeof(struct blk_zone)));
kfree(seq_zones_wlock);
kfree(seq_zones_bitmap);
if (ret) {
pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
blk_mq_freeze_queue(q);
blk_queue_free_zone_bitmaps(q);
blk_mq_unfreeze_queue(q);
}
return ret;
}
EXPORT_SYMBOL_GPL(blk_revalidate_disk_zones);