linux/block/blk-zoned.c
Christoph Hellwig 74d46992e0 block: replace bi_bdev with a gendisk pointer and partitions index
This way we don't need a block_device structure to submit I/O.  The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open.  Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).

For the actual I/O path all that we need is the gendisk, which exists
once per block device.  But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.

Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23 12:49:55 -06:00

349 lines
7.6 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>
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;
}
/*
* Check that a zone report belongs to the partition.
* If yes, fix its start sector and write pointer, copy it in the
* zone information array and return true. Return false otherwise.
*/
static bool blkdev_report_zone(struct block_device *bdev,
struct blk_zone *rep,
struct blk_zone *zone)
{
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;
memcpy(zone, rep, sizeof(struct blk_zone));
return true;
}
/**
* 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);
struct blk_zone_report_hdr *hdr;
unsigned int nrz = *nr_zones;
struct page *page;
unsigned int nr_rep;
size_t rep_bytes;
unsigned int nr_pages;
struct bio *bio;
struct bio_vec *bv;
unsigned int i, n, nz;
unsigned int ofst;
void *addr;
int ret;
if (!q)
return -ENXIO;
if (!blk_queue_is_zoned(q))
return -EOPNOTSUPP;
if (!nrz)
return 0;
if (sector > bdev->bd_part->nr_sects) {
*nr_zones = 0;
return 0;
}
/*
* The zone report has a header. So make room for it in the
* payload. Also make sure that the report fits in a single BIO
* that will not be split down the stack.
*/
rep_bytes = sizeof(struct blk_zone_report_hdr) +
sizeof(struct blk_zone) * nrz;
rep_bytes = (rep_bytes + PAGE_SIZE - 1) & PAGE_MASK;
if (rep_bytes > (queue_max_sectors(q) << 9))
rep_bytes = queue_max_sectors(q) << 9;
nr_pages = min_t(unsigned int, BIO_MAX_PAGES,
rep_bytes >> PAGE_SHIFT);
nr_pages = min_t(unsigned int, nr_pages,
queue_max_segments(q));
bio = bio_alloc(gfp_mask, nr_pages);
if (!bio)
return -ENOMEM;
bio_set_dev(bio, bdev);
bio->bi_iter.bi_sector = blk_zone_start(q, sector);
bio_set_op_attrs(bio, REQ_OP_ZONE_REPORT, 0);
for (i = 0; i < nr_pages; i++) {
page = alloc_page(gfp_mask);
if (!page) {
ret = -ENOMEM;
goto out;
}
if (!bio_add_page(bio, page, PAGE_SIZE, 0)) {
__free_page(page);
break;
}
}
if (i == 0)
ret = -ENOMEM;
else
ret = submit_bio_wait(bio);
if (ret)
goto out;
/*
* Process the report result: skip the header and go through the
* reported zones to fixup and fixup the zone information for
* partitions. At the same time, return the zone information into
* the zone array.
*/
n = 0;
nz = 0;
nr_rep = 0;
bio_for_each_segment_all(bv, bio, i) {
if (!bv->bv_page)
break;
addr = kmap_atomic(bv->bv_page);
/* Get header in the first page */
ofst = 0;
if (!nr_rep) {
hdr = (struct blk_zone_report_hdr *) addr;
nr_rep = hdr->nr_zones;
ofst = sizeof(struct blk_zone_report_hdr);
}
/* Fixup and report zones */
while (ofst < bv->bv_len &&
n < nr_rep && nz < nrz) {
if (blkdev_report_zone(bdev, addr + ofst, &zones[nz]))
nz++;
ofst += sizeof(struct blk_zone);
n++;
}
kunmap_atomic(addr);
if (n >= nr_rep || nz >= nrz)
break;
}
*nr_zones = nz;
out:
bio_for_each_segment_all(bv, bio, i)
__free_page(bv->bv_page);
bio_put(bio);
return ret;
}
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;
int ret;
if (!q)
return -ENXIO;
if (!blk_queue_is_zoned(q))
return -EOPNOTSUPP;
if (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;
while (sector < end_sector) {
bio = bio_alloc(gfp_mask, 0);
bio->bi_iter.bi_sector = sector;
bio_set_dev(bio, bdev);
bio_set_op_attrs(bio, REQ_OP_ZONE_RESET, 0);
ret = submit_bio_wait(bio);
bio_put(bio);
if (ret)
return ret;
sector += zone_sectors;
/* This may take a while, so be nice to others */
cond_resched();
}
return 0;
}
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;
zones = kcalloc(rep.nr_zones, sizeof(struct blk_zone), GFP_KERNEL);
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:
kfree(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);
}