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1365b6904f
linux/block/blk-zoned.c
Damien Le Moal 1365b6904f block: allow submitting all zone writes from a single context 
In order to maintain sequential write patterns per zone with zoned block
devices, zone write plugging issues only a single write BIO per zone at
any time. This works well but has the side effect that when large
sequential write streams are issued by the user and these streams cross
zone boundaries, the device ends up receiving a discontiguous set of
write commands for different zones. The same also happens when a user
writes simultaneously at high queue depth multiple zones: the device
does not see all sequential writes per zone and receives discontiguous
writes to different zones. While this does not affect the performance of
solid state zoned block devices, when using an SMR HDD, this pattern
change from sequential writes to discontiguous writes to different zones
significantly increases head seek which results in degraded write
throughput.

In order to reduce this seek overhead for rotational media devices,
introduce a per disk zone write plugs kernel thread to issue all write
BIOs to zones. This single zone write issuing context is enabled for
any zoned block device that has a request queue flagged with the new
QUEUE_ZONED_QD1_WRITES flag.

The flag QUEUE_ZONED_QD1_WRITES is visible as the sysfs queue attribute
zoned_qd1_writes for zoned devices. For regular block devices, this
attribute is not visible. For zoned block devices, a user can override
the default value set to force the global write maximum queue depth of
1 for a zoned block device, or clear this attribute to fallback to the
default behavior of zone write plugging which limits writes to QD=1 per
sequential zone.

Writing to a zoned block device flagged with QUEUE_ZONED_QD1_WRITES is
implemented using a list of zone write plugs that have a non-empty BIO
list. Listed zone write plugs are processed by the disk zone write plugs
worker kthread in FIFO order, and all BIOs of a zone write plug are all
processed before switching to the next listed zone write plug. A newly
submitted BIO for a non-FULL zone write plug that is not yet listed
causes the addition of the zone write plug at the end of the disk list
of zone write plugs.

Since the write BIOs queued in a zone write plug BIO list are
necessarilly sequential, for rotational media, using the single zone
write plugs kthread to issue all BIOs maintains a sequential write
pattern and thus reduces seek overhead and improves write throughput.
This processing essentially result in always writing to HDDs at QD=1,
which is not an issue for HDDs operating with write caching enabled.
Performance with write cache disabled is also not degraded thanks to
the efficient write handling of modern SMR HDDs.

A disk list of zone write plugs is defined using the new struct gendisk
zone_wplugs_list, and accesses to this list is protected using the
zone_wplugs_list_lock spinlock.  The per disk kthread
(zone_wplugs_worker) code is implemented by the function
disk_zone_wplugs_worker(). A reference on listed zone write plugs is
always held until all BIOs of the zone write plug are processed by the
worker kthread. BIO issuing at QD=1 is driven using a completion
structure (zone_wplugs_worker_bio_done) and calls to blk_io_wait().

With this change, performance when sequentially writing the zones of a
30 TB SMR SATA HDD connected to an AHCI adapter changes as follows
(1MiB direct I/Os, results in MB/s unit):

                    +--------------------+
		    |   Write BW (MB/s)  |
 +------------------+----------+---------+
 | Sequential write | Baseline | Patched |
 |  Queue Depth     | 6.19-rc8 |         |
 +------------------+----------+---------+
 | 1                | 244      | 245     |
 | 2                | 244      | 245     |
 | 4                | 245      | 245     |
 | 8                | 242      | 245     |
 | 16               | 222      | 246     |
 | 32               | 211      | 245     |
 | 64               | 193      | 244     |
 | 128              | 112      | 246     |
 +------------------+----------+---------+

With the current code (baseline), as the sequential write stream crosses
a zone boundary, higher queue depth creates a gap between the
last IO to the previous zone and the first IOs to the following zones,
causing head seeks and degrading performance. Using the disk zone
write plugs worker thread, this pattern disappears and the maximum
throughput of the drive is maintained, leading to over 100%
improvements in throughput for high queue depth write.

Using 16 fio jobs all writing to randomly chosen zones at QD=32 with 1
MiB direct IOs, write throughput also increases significantly.

                    +--------------------+
		    |   Write BW (MB/s)  |
 +------------------+----------+---------+
 |   Random write   | Baseline | Patched |
 |  Number of zones | 6.19-rc7 |         |
 +------------------+----------+---------+
 | 1                | 191      | 192     |
 | 2                | 101      | 128     |
 | 4                | 115      | 123     |
 | 8                | 90       | 120     |
 | 16               | 64       | 115     |
 | 32               | 58       | 105     |
 | 64               | 56       | 101     |
 | 128              | 55       | 99      |
 +------------------+----------+---------+

Tests using XFS shows that buffered write speed with 8 jobs writing
files increases by 12% to 35% depending on the workload.

                    +--------------------+
		    |   Write BW (MB/s)  |
 +------------------+----------+---------+
 |     Workload     | Baseline | Patched |
 |                  | 6.19-rc7 |         |
 +------------------+----------+---------+
 | 256MiB file size | 212      | 238     |
 +------------------+----------+---------+
 | 4MiB .. 128 MiB  | 213      | 243     |
 | random file size |          |         |
 +------------------+----------+---------+
 | 2MiB .. 8 MiB    | 179      | 242     |
 | random file size |          |         |
 +------------------+----------+---------+

Performance gains are even more significant when using an HBA that
limits the maximum size of commands to a small value, e.g. HBAs
controlled with the mpi3mr driver limit commands to a maximum of 1 MiB.
In such case, the write throughput gains are over 40%.

                    +--------------------+
		    |   Write BW (MB/s)  |
 +------------------+----------+---------+
 |     Workload     | Baseline | Patched |
 |                  | 6.19-rc7 |         |
 +------------------+----------+---------+
 | 256MiB file size | 175      | 245     |
 +------------------+----------+---------+
 | 4MiB .. 128 MiB  | 174      | 244     |
 | random file size |          |         |
 +------------------+----------+---------+
 | 2MiB .. 8 MiB    | 171      | 243     |
 | random file size |          |         |
 +------------------+----------+---------+

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-09 14:30:00 -06:00

2468 lines
70 KiB
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// SPDX-License-Identifier: GPL-2.0
/*
* 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
* Copyright (c) 2024, Western Digital Corporation or its affiliates.
*/
#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include <linux/spinlock.h>
#include <linux/refcount.h>
#include <linux/mempool.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <trace/events/block.h>
#include "blk.h"
#include "blk-mq-sched.h"
#include "blk-mq-debugfs.h"
#define ZONE_COND_NAME(name) [BLK_ZONE_COND_##name] = #name
static const char *const zone_cond_name[] = {
ZONE_COND_NAME(NOT_WP),
ZONE_COND_NAME(EMPTY),
ZONE_COND_NAME(IMP_OPEN),
ZONE_COND_NAME(EXP_OPEN),
ZONE_COND_NAME(CLOSED),
ZONE_COND_NAME(READONLY),
ZONE_COND_NAME(FULL),
ZONE_COND_NAME(OFFLINE),
ZONE_COND_NAME(ACTIVE),
};
#undef ZONE_COND_NAME
/*
* Per-zone write plug.
* @node: hlist_node structure for managing the plug using a hash table.
* @entry: list_head structure for listing the plug in the disk list of active
* zone write plugs.
* @bio_list: The list of BIOs that are currently plugged.
* @bio_work: Work struct to handle issuing of plugged BIOs
* @rcu_head: RCU head to free zone write plugs with an RCU grace period.
* @disk: The gendisk the plug belongs to.
* @lock: Spinlock to atomically manipulate the plug.
* @ref: Zone write plug reference counter. A zone write plug reference is
* always at least 1 when the plug is hashed in the disk plug hash table.
* The reference is incremented whenever a new BIO needing plugging is
* submitted and when a function needs to manipulate a plug. The
* reference count is decremented whenever a plugged BIO completes and
* when a function that referenced the plug returns. The initial
* reference is dropped whenever the zone of the zone write plug is reset,
* finished and when the zone becomes full (last write BIO to the zone
* completes).
* @flags: Flags indicating the plug state.
* @zone_no: The number of the zone the plug is managing.
* @wp_offset: The zone write pointer location relative to the start of the zone
* as a number of 512B sectors.
* @cond: Condition of the zone
*/
struct blk_zone_wplug {
struct hlist_node node;
struct list_head entry;
struct bio_list bio_list;
struct work_struct bio_work;
struct rcu_head rcu_head;
struct gendisk *disk;
spinlock_t lock;
refcount_t ref;
unsigned int flags;
unsigned int zone_no;
unsigned int wp_offset;
enum blk_zone_cond cond;
};
static inline bool disk_need_zone_resources(struct gendisk *disk)
{
/*
* All request-based zoned devices need zone resources so that the
* block layer can automatically handle write BIO plugging. BIO-based
* device drivers (e.g. DM devices) are normally responsible for
* handling zone write ordering and do not need zone resources, unless
* the driver requires zone append emulation.
*/
return queue_is_mq(disk->queue) ||
queue_emulates_zone_append(disk->queue);
}
static inline unsigned int disk_zone_wplugs_hash_size(struct gendisk *disk)
{
return 1U << disk->zone_wplugs_hash_bits;
}
/*
* Zone write plug flags bits:
* - BLK_ZONE_WPLUG_PLUGGED: Indicates that the zone write plug is plugged,
* that is, that write BIOs are being throttled due to a write BIO already
* being executed or the zone write plug bio list is not empty.
* - BLK_ZONE_WPLUG_NEED_WP_UPDATE: Indicates that we lost track of a zone
* write pointer offset and need to update it.
* - BLK_ZONE_WPLUG_DEAD: Indicates that the zone write plug will be
* removed from the disk hash table of zone write plugs when the last
* reference on the zone write plug is dropped. If set, this flag also
* indicates that the initial extra reference on the zone write plug was
* dropped, meaning that the reference count indicates the current number of
* active users (code context or BIOs and requests in flight). This flag is
* set when a zone is reset, finished or becomes full.
*/
#define BLK_ZONE_WPLUG_PLUGGED (1U << 0)
#define BLK_ZONE_WPLUG_NEED_WP_UPDATE (1U << 1)
#define BLK_ZONE_WPLUG_DEAD (1U << 2)
/**
* blk_zone_cond_str - Return a zone condition name string
* @zone_cond: a zone condition BLK_ZONE_COND_name
*
* Convert a BLK_ZONE_COND_name zone condition into the string "name". Useful
* for the debugging and tracing zone conditions. For an invalid zone
* conditions, the string "UNKNOWN" is returned.
*/
const char *blk_zone_cond_str(enum blk_zone_cond zone_cond)
{
static const char *zone_cond_str = "UNKNOWN";
if (zone_cond < ARRAY_SIZE(zone_cond_name) && zone_cond_name[zone_cond])
zone_cond_str = zone_cond_name[zone_cond];
return zone_cond_str;
}
EXPORT_SYMBOL_GPL(blk_zone_cond_str);
static void blk_zone_set_cond(u8 *zones_cond, unsigned int zno,
enum blk_zone_cond cond)
{
if (!zones_cond)
return;
switch (cond) {
case BLK_ZONE_COND_IMP_OPEN:
case BLK_ZONE_COND_EXP_OPEN:
case BLK_ZONE_COND_CLOSED:
zones_cond[zno] = BLK_ZONE_COND_ACTIVE;
return;
case BLK_ZONE_COND_NOT_WP:
case BLK_ZONE_COND_EMPTY:
case BLK_ZONE_COND_FULL:
case BLK_ZONE_COND_OFFLINE:
case BLK_ZONE_COND_READONLY:
default:
zones_cond[zno] = cond;
return;
}
}
static void disk_zone_set_cond(struct gendisk *disk, sector_t sector,
enum blk_zone_cond cond)
{
u8 *zones_cond;
rcu_read_lock();
zones_cond = rcu_dereference(disk->zones_cond);
if (zones_cond) {
unsigned int zno = disk_zone_no(disk, sector);
/*
* The condition of a conventional, readonly and offline zones
* never changes, so do nothing if the target zone is in one of
* these conditions.
*/
switch (zones_cond[zno]) {
case BLK_ZONE_COND_NOT_WP:
case BLK_ZONE_COND_READONLY:
case BLK_ZONE_COND_OFFLINE:
break;
default:
blk_zone_set_cond(zones_cond, zno, cond);
break;
}
}
rcu_read_unlock();
}
/**
* bdev_zone_is_seq - check if a sector belongs to a sequential write zone
* @bdev: block device to check
* @sector: sector number
*
* Check if @sector on @bdev is contained in a sequential write required zone.
*/
bool bdev_zone_is_seq(struct block_device *bdev, sector_t sector)
{
struct gendisk *disk = bdev->bd_disk;
unsigned int zno = disk_zone_no(disk, sector);
bool is_seq = false;
u8 *zones_cond;
if (!bdev_is_zoned(bdev))
return false;
rcu_read_lock();
zones_cond = rcu_dereference(disk->zones_cond);
if (zones_cond && zno < disk->nr_zones)
is_seq = zones_cond[zno] != BLK_ZONE_COND_NOT_WP;
rcu_read_unlock();
return is_seq;
}
EXPORT_SYMBOL_GPL(bdev_zone_is_seq);
/*
* Zone report arguments for block device drivers report_zones operation.
* @cb: report_zones_cb callback for each reported zone.
* @data: Private data passed to report_zones_cb.
*/
struct blk_report_zones_args {
report_zones_cb cb;
void *data;
bool report_active;
};
static int blkdev_do_report_zones(struct block_device *bdev, sector_t sector,
unsigned int nr_zones,
struct blk_report_zones_args *args)
{
struct gendisk *disk = bdev->bd_disk;
if (!bdev_is_zoned(bdev) || WARN_ON_ONCE(!disk->fops->report_zones))
return -EOPNOTSUPP;
if (!nr_zones || sector >= get_capacity(disk))
return 0;
return disk->fops->report_zones(disk, sector, nr_zones, args);
}
/**
* blkdev_report_zones - Get zones information
* @bdev: Target block device
* @sector: Sector from which to report zones
* @nr_zones: Maximum number of zones to report
* @cb: Callback function called for each reported zone
* @data: Private data for the callback
*
* Description:
* Get zone information starting from the zone containing @sector for at most
* @nr_zones, and call @cb for each zone reported by the device.
* To report all zones in a device starting from @sector, the BLK_ALL_ZONES
* constant can be passed to @nr_zones.
* Returns the number of zones reported by the device, or a negative errno
* value in case of failure.
*
* Note: The caller must use memalloc_noXX_save/restore() calls to control
* memory allocations done within this function.
*/
int blkdev_report_zones(struct block_device *bdev, sector_t sector,
unsigned int nr_zones, report_zones_cb cb, void *data)
{
struct blk_report_zones_args args = {
.cb = cb,
.data = data,
};
return blkdev_do_report_zones(bdev, sector, nr_zones, &args);
}
EXPORT_SYMBOL_GPL(blkdev_report_zones);
static int blkdev_zone_reset_all(struct block_device *bdev)
{
struct bio bio;
bio_init(&bio, bdev, NULL, 0, REQ_OP_ZONE_RESET_ALL | REQ_SYNC);
trace_blkdev_zone_mgmt(&bio, 0);
return submit_bio_wait(&bio);
}
/**
* blkdev_zone_mgmt - Execute a zone management operation on a range of zones
* @bdev: Target block device
* @op: Operation to be performed on the zones
* @sector: Start sector of the first zone to operate on
* @nr_sectors: Number of sectors, should be at least the length of one zone and
* must be zone size aligned.
*
* Description:
* Perform the specified operation on the range of zones specified by
* @sector..@sector+@nr_sectors. Specifying the entire disk sector range
* is valid, but the specified range should not contain conventional zones.
* The operation to execute on each zone can be a zone reset, open, close
* or finish request.
*/
int blkdev_zone_mgmt(struct block_device *bdev, enum req_op op,
sector_t sector, sector_t nr_sectors)
{
sector_t zone_sectors = bdev_zone_sectors(bdev);
sector_t capacity = bdev_nr_sectors(bdev);
sector_t end_sector = sector + nr_sectors;
struct bio *bio = NULL;
int ret = 0;
if (!bdev_is_zoned(bdev))
return -EOPNOTSUPP;
if (bdev_read_only(bdev))
return -EPERM;
if (!op_is_zone_mgmt(op))
return -EOPNOTSUPP;
if (end_sector <= sector || end_sector > capacity)
/* Out of range */
return -EINVAL;
/* Check alignment (handle eventual smaller last zone) */
if (!bdev_is_zone_start(bdev, sector))
return -EINVAL;
if (!bdev_is_zone_start(bdev, nr_sectors) && end_sector != capacity)
return -EINVAL;
/*
* In the case of a zone reset operation over all zones, use
* REQ_OP_ZONE_RESET_ALL.
*/
if (op == REQ_OP_ZONE_RESET && sector == 0 && nr_sectors == capacity)
return blkdev_zone_reset_all(bdev);
while (sector < end_sector) {
bio = blk_next_bio(bio, bdev, 0, op | REQ_SYNC, GFP_KERNEL);
bio->bi_iter.bi_sector = sector;
sector += zone_sectors;
/* This may take a while, so be nice to others */
cond_resched();
}
trace_blkdev_zone_mgmt(bio, nr_sectors);
ret = submit_bio_wait(bio);
bio_put(bio);
return ret;
}
EXPORT_SYMBOL_GPL(blkdev_zone_mgmt);
struct zone_report_args {
struct blk_zone __user *zones;
};
static int blkdev_copy_zone_to_user(struct blk_zone *zone, unsigned int idx,
void *data)
{
struct zone_report_args *args = data;
if (copy_to_user(&args->zones[idx], zone, sizeof(struct blk_zone)))
return -EFAULT;
return 0;
}
/*
* Mask of valid input flags for BLKREPORTZONEV2 ioctl.
*/
#define BLK_ZONE_REPV2_INPUT_FLAGS BLK_ZONE_REP_CACHED
/*
* BLKREPORTZONE and BLKREPORTZONEV2 ioctl processing.
* Called from blkdev_ioctl.
*/
int blkdev_report_zones_ioctl(struct block_device *bdev, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
struct zone_report_args args;
struct blk_zone_report rep;
int ret;
if (!argp)
return -EINVAL;
if (!bdev_is_zoned(bdev))
return -ENOTTY;
if (copy_from_user(&rep, argp, sizeof(struct blk_zone_report)))
return -EFAULT;
if (!rep.nr_zones)
return -EINVAL;
args.zones = argp + sizeof(struct blk_zone_report);
switch (cmd) {
case BLKREPORTZONE:
ret = blkdev_report_zones(bdev, rep.sector, rep.nr_zones,
blkdev_copy_zone_to_user, &args);
break;
case BLKREPORTZONEV2:
if (rep.flags & ~BLK_ZONE_REPV2_INPUT_FLAGS)
return -EINVAL;
ret = blkdev_report_zones_cached(bdev, rep.sector, rep.nr_zones,
blkdev_copy_zone_to_user, &args);
break;
default:
return -EINVAL;
}
if (ret < 0)
return ret;
rep.nr_zones = ret;
rep.flags = BLK_ZONE_REP_CAPACITY;
if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report)))
return -EFAULT;
return 0;
}
static int blkdev_truncate_zone_range(struct block_device *bdev,
blk_mode_t mode, const struct blk_zone_range *zrange)
{
loff_t start, end;
if (zrange->sector + zrange->nr_sectors <= zrange->sector ||
zrange->sector + zrange->nr_sectors > get_capacity(bdev->bd_disk))
/* Out of range */
return -EINVAL;
start = zrange->sector << SECTOR_SHIFT;
end = ((zrange->sector + zrange->nr_sectors) << SECTOR_SHIFT) - 1;
return truncate_bdev_range(bdev, mode, start, end);
}
/*
* BLKRESETZONE, BLKOPENZONE, BLKCLOSEZONE and BLKFINISHZONE ioctl processing.
* Called from blkdev_ioctl.
*/
int blkdev_zone_mgmt_ioctl(struct block_device *bdev, blk_mode_t mode,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
struct blk_zone_range zrange;
enum req_op op;
int ret;
if (!argp)
return -EINVAL;
if (!bdev_is_zoned(bdev))
return -ENOTTY;
if (!(mode & BLK_OPEN_WRITE))
return -EBADF;
if (copy_from_user(&zrange, argp, sizeof(struct blk_zone_range)))
return -EFAULT;
switch (cmd) {
case BLKRESETZONE:
op = REQ_OP_ZONE_RESET;
/* Invalidate the page cache, including dirty pages. */
inode_lock(bdev->bd_mapping->host);
filemap_invalidate_lock(bdev->bd_mapping);
ret = blkdev_truncate_zone_range(bdev, mode, &zrange);
if (ret)
goto fail;
break;
case BLKOPENZONE:
op = REQ_OP_ZONE_OPEN;
break;
case BLKCLOSEZONE:
op = REQ_OP_ZONE_CLOSE;
break;
case BLKFINISHZONE:
op = REQ_OP_ZONE_FINISH;
break;
default:
return -ENOTTY;
}
ret = blkdev_zone_mgmt(bdev, op, zrange.sector, zrange.nr_sectors);
fail:
if (cmd == BLKRESETZONE) {
filemap_invalidate_unlock(bdev->bd_mapping);
inode_unlock(bdev->bd_mapping->host);
}
return ret;
}
static bool disk_zone_is_last(struct gendisk *disk, struct blk_zone *zone)
{
return zone->start + zone->len >= get_capacity(disk);
}
static bool disk_zone_wplug_is_full(struct gendisk *disk,
struct blk_zone_wplug *zwplug)
{
if (zwplug->zone_no < disk->nr_zones - 1)
return zwplug->wp_offset >= disk->zone_capacity;
return zwplug->wp_offset >= disk->last_zone_capacity;
}
static bool disk_insert_zone_wplug(struct gendisk *disk,
struct blk_zone_wplug *zwplug)
{
struct blk_zone_wplug *zwplg;
unsigned long flags;
u8 *zones_cond;
unsigned int idx =
hash_32(zwplug->zone_no, disk->zone_wplugs_hash_bits);
/*
* Add the new zone write plug to the hash table, but carefully as we
* are racing with other submission context, so we may already have a
* zone write plug for the same zone.
*/
spin_lock_irqsave(&disk->zone_wplugs_hash_lock, flags);
hlist_for_each_entry_rcu(zwplg, &disk->zone_wplugs_hash[idx], node) {
if (zwplg->zone_no == zwplug->zone_no) {
spin_unlock_irqrestore(&disk->zone_wplugs_hash_lock,
flags);
return false;
}
}
/*
* Set the zone condition: if we do not yet have a zones_cond array
* attached to the disk, then this is a zone write plug insert from the
* first call to blk_revalidate_disk_zones(), in which case the zone is
* necessarilly in the active condition.
*/
zones_cond = rcu_dereference_check(disk->zones_cond,
lockdep_is_held(&disk->zone_wplugs_hash_lock));
if (zones_cond)
zwplug->cond = zones_cond[zwplug->zone_no];
else
zwplug->cond = BLK_ZONE_COND_ACTIVE;
hlist_add_head_rcu(&zwplug->node, &disk->zone_wplugs_hash[idx]);
atomic_inc(&disk->nr_zone_wplugs);
spin_unlock_irqrestore(&disk->zone_wplugs_hash_lock, flags);
return true;
}
static struct blk_zone_wplug *disk_get_hashed_zone_wplug(struct gendisk *disk,
sector_t sector)
{
unsigned int zno = disk_zone_no(disk, sector);
unsigned int idx = hash_32(zno, disk->zone_wplugs_hash_bits);
struct blk_zone_wplug *zwplug;
rcu_read_lock();
hlist_for_each_entry_rcu(zwplug, &disk->zone_wplugs_hash[idx], node) {
if (zwplug->zone_no == zno &&
refcount_inc_not_zero(&zwplug->ref)) {
rcu_read_unlock();
return zwplug;
}
}
rcu_read_unlock();
return NULL;
}
static inline struct blk_zone_wplug *disk_get_zone_wplug(struct gendisk *disk,
sector_t sector)
{
if (!atomic_read(&disk->nr_zone_wplugs))
return NULL;
return disk_get_hashed_zone_wplug(disk, sector);
}
static void disk_free_zone_wplug_rcu(struct rcu_head *rcu_head)
{
struct blk_zone_wplug *zwplug =
container_of(rcu_head, struct blk_zone_wplug, rcu_head);
mempool_free(zwplug, zwplug->disk->zone_wplugs_pool);
}
static void disk_free_zone_wplug(struct blk_zone_wplug *zwplug)
{
struct gendisk *disk = zwplug->disk;
unsigned long flags;
WARN_ON_ONCE(!(zwplug->flags & BLK_ZONE_WPLUG_DEAD));
WARN_ON_ONCE(zwplug->flags & BLK_ZONE_WPLUG_PLUGGED);
WARN_ON_ONCE(!bio_list_empty(&zwplug->bio_list));
spin_lock_irqsave(&disk->zone_wplugs_hash_lock, flags);
blk_zone_set_cond(rcu_dereference_check(disk->zones_cond,
lockdep_is_held(&disk->zone_wplugs_hash_lock)),
zwplug->zone_no, zwplug->cond);
hlist_del_init_rcu(&zwplug->node);
atomic_dec(&disk->nr_zone_wplugs);
spin_unlock_irqrestore(&disk->zone_wplugs_hash_lock, flags);
call_rcu(&zwplug->rcu_head, disk_free_zone_wplug_rcu);
}
static inline void disk_put_zone_wplug(struct blk_zone_wplug *zwplug)
{
if (refcount_dec_and_test(&zwplug->ref))
disk_free_zone_wplug(zwplug);
}
/*
* Flag the zone write plug as dead and drop the initial reference we got when
* the zone write plug was added to the hash table. The zone write plug will be
* unhashed when its last reference is dropped.
*/
static void disk_mark_zone_wplug_dead(struct blk_zone_wplug *zwplug)
{
lockdep_assert_held(&zwplug->lock);
if (!(zwplug->flags & BLK_ZONE_WPLUG_DEAD)) {
zwplug->flags |= BLK_ZONE_WPLUG_DEAD;
disk_put_zone_wplug(zwplug);
}
}
static bool disk_zone_wplug_submit_bio(struct gendisk *disk,
struct blk_zone_wplug *zwplug);
static void blk_zone_wplug_bio_work(struct work_struct *work)
{
struct blk_zone_wplug *zwplug =
container_of(work, struct blk_zone_wplug, bio_work);
disk_zone_wplug_submit_bio(zwplug->disk, zwplug);
/* Drop the reference we took in disk_zone_wplug_schedule_work(). */
disk_put_zone_wplug(zwplug);
}
/*
* Get a zone write plug for the zone containing @sector.
* If the plug does not exist, it is allocated and inserted in the disk hash
* table.
*/
static struct blk_zone_wplug *disk_get_or_alloc_zone_wplug(struct gendisk *disk,
sector_t sector, gfp_t gfp_mask)
{
unsigned int zno = disk_zone_no(disk, sector);
struct blk_zone_wplug *zwplug;
again:
zwplug = disk_get_zone_wplug(disk, sector);
if (zwplug)
return zwplug;
/*
* Allocate and initialize a zone write plug with an extra reference
* so that it is not freed when the zone write plug becomes idle without
* the zone being full.
*/
zwplug = mempool_alloc(disk->zone_wplugs_pool, gfp_mask);
if (!zwplug)
return NULL;
INIT_HLIST_NODE(&zwplug->node);
refcount_set(&zwplug->ref, 2);
spin_lock_init(&zwplug->lock);
zwplug->flags = 0;
zwplug->zone_no = zno;
zwplug->wp_offset = bdev_offset_from_zone_start(disk->part0, sector);
bio_list_init(&zwplug->bio_list);
INIT_WORK(&zwplug->bio_work, blk_zone_wplug_bio_work);
INIT_LIST_HEAD(&zwplug->entry);
zwplug->disk = disk;
/*
* Insert the new zone write plug in the hash table. This can fail only
* if another context already inserted a plug. Retry from the beginning
* in such case.
*/
if (!disk_insert_zone_wplug(disk, zwplug)) {
mempool_free(zwplug, disk->zone_wplugs_pool);
goto again;
}
return zwplug;
}
static inline void blk_zone_wplug_bio_io_error(struct blk_zone_wplug *zwplug,
struct bio *bio)
{
struct request_queue *q = zwplug->disk->queue;
bio_clear_flag(bio, BIO_ZONE_WRITE_PLUGGING);
bio_io_error(bio);
disk_put_zone_wplug(zwplug);
/* Drop the reference taken by disk_zone_wplug_add_bio(). */
blk_queue_exit(q);
}
/*
* Abort (fail) all plugged BIOs of a zone write plug.
*/
static void disk_zone_wplug_abort(struct blk_zone_wplug *zwplug)
{
struct gendisk *disk = zwplug->disk;
struct bio *bio;
lockdep_assert_held(&zwplug->lock);
if (bio_list_empty(&zwplug->bio_list))
return;
pr_warn_ratelimited("%s: zone %u: Aborting plugged BIOs\n",
zwplug->disk->disk_name, zwplug->zone_no);
while ((bio = bio_list_pop(&zwplug->bio_list)))
blk_zone_wplug_bio_io_error(zwplug, bio);
zwplug->flags &= ~BLK_ZONE_WPLUG_PLUGGED;
/*
* If we are using the per disk zone write plugs worker thread, remove
* the zone write plug from the work list and drop the reference we
* took when the zone write plug was added to that list.
*/
if (blk_queue_zoned_qd1_writes(disk->queue)) {
spin_lock(&disk->zone_wplugs_list_lock);
if (!list_empty(&zwplug->entry)) {
list_del_init(&zwplug->entry);
disk_put_zone_wplug(zwplug);
}
spin_unlock(&disk->zone_wplugs_list_lock);
}
}
/*
* Update a zone write plug condition based on the write pointer offset.
*/
static void disk_zone_wplug_update_cond(struct gendisk *disk,
struct blk_zone_wplug *zwplug)
{
lockdep_assert_held(&zwplug->lock);
if (disk_zone_wplug_is_full(disk, zwplug))
zwplug->cond = BLK_ZONE_COND_FULL;
else if (!zwplug->wp_offset)
zwplug->cond = BLK_ZONE_COND_EMPTY;
else
zwplug->cond = BLK_ZONE_COND_ACTIVE;
}
/*
* Set a zone write plug write pointer offset to the specified value.
* This aborts all plugged BIOs, which is fine as this function is called for
* a zone reset operation, a zone finish operation or if the zone needs a wp
* update from a report zone after a write error.
*/
static void disk_zone_wplug_set_wp_offset(struct gendisk *disk,
struct blk_zone_wplug *zwplug,
unsigned int wp_offset)
{
lockdep_assert_held(&zwplug->lock);
/* Update the zone write pointer and abort all plugged BIOs. */
zwplug->flags &= ~BLK_ZONE_WPLUG_NEED_WP_UPDATE;
zwplug->wp_offset = wp_offset;
disk_zone_wplug_update_cond(disk, zwplug);
disk_zone_wplug_abort(zwplug);
if (!zwplug->wp_offset || disk_zone_wplug_is_full(disk, zwplug))
disk_mark_zone_wplug_dead(zwplug);
}
static unsigned int blk_zone_wp_offset(struct blk_zone *zone)
{
switch (zone->cond) {
case BLK_ZONE_COND_IMP_OPEN:
case BLK_ZONE_COND_EXP_OPEN:
case BLK_ZONE_COND_CLOSED:
case BLK_ZONE_COND_ACTIVE:
return zone->wp - zone->start;
case BLK_ZONE_COND_EMPTY:
return 0;
case BLK_ZONE_COND_FULL:
case BLK_ZONE_COND_NOT_WP:
case BLK_ZONE_COND_OFFLINE:
case BLK_ZONE_COND_READONLY:
default:
/*
* Conventional, full, offline and read-only zones do not have
* a valid write pointer.
*/
return UINT_MAX;
}
}
static unsigned int disk_zone_wplug_sync_wp_offset(struct gendisk *disk,
struct blk_zone *zone)
{
struct blk_zone_wplug *zwplug;
unsigned int wp_offset = blk_zone_wp_offset(zone);
zwplug = disk_get_zone_wplug(disk, zone->start);
if (zwplug) {
unsigned long flags;
spin_lock_irqsave(&zwplug->lock, flags);
if (zwplug->flags & BLK_ZONE_WPLUG_NEED_WP_UPDATE)
disk_zone_wplug_set_wp_offset(disk, zwplug, wp_offset);
spin_unlock_irqrestore(&zwplug->lock, flags);
disk_put_zone_wplug(zwplug);
}
return wp_offset;
}
/**
* disk_report_zone - Report one zone
* @disk: Target disk
* @zone: The zone to report
* @idx: The index of the zone in the overall zone report
* @args: report zones callback and data
*
* Description:
* Helper function for block device drivers to report one zone of a zone
* report initiated with blkdev_report_zones(). The zone being reported is
* specified by @zone and used to update, if necessary, the zone write plug
* information for the zone. If @args specifies a user callback function,
* this callback is executed.
*/
int disk_report_zone(struct gendisk *disk, struct blk_zone *zone,
unsigned int idx, struct blk_report_zones_args *args)
{
if (args && args->report_active) {
/*
* If we come here, then this is a report zones as a fallback
* for a cached report. So collapse the implicit open, explicit
* open and closed conditions into the active zone condition.
*/
switch (zone->cond) {
case BLK_ZONE_COND_IMP_OPEN:
case BLK_ZONE_COND_EXP_OPEN:
case BLK_ZONE_COND_CLOSED:
zone->cond = BLK_ZONE_COND_ACTIVE;
break;
default:
break;
}
}
if (disk->zone_wplugs_hash)
disk_zone_wplug_sync_wp_offset(disk, zone);
if (args && args->cb)
return args->cb(zone, idx, args->data);
return 0;
}
EXPORT_SYMBOL_GPL(disk_report_zone);
static int blkdev_report_zone_cb(struct blk_zone *zone, unsigned int idx,
void *data)
{
memcpy(data, zone, sizeof(struct blk_zone));
return 0;
}
static int blkdev_report_zone_fallback(struct block_device *bdev,
sector_t sector, struct blk_zone *zone)
{
struct blk_report_zones_args args = {
.cb = blkdev_report_zone_cb,
.data = zone,
.report_active = true,
};
int error;
error = blkdev_do_report_zones(bdev, sector, 1, &args);
if (error < 0)
return error;
if (error == 0)
return -EIO;
return 0;
}
/*
* For devices that natively support zone append operations, we do not use zone
* write plugging for zone append writes, which makes the zone condition
* tracking invalid once zone append was used. In that case fall back to a
* regular report zones to get correct information.
*/
static inline bool blkdev_has_cached_report_zones(struct block_device *bdev)
{
return disk_need_zone_resources(bdev->bd_disk) &&
(bdev_emulates_zone_append(bdev) ||
!test_bit(GD_ZONE_APPEND_USED, &bdev->bd_disk->state));
}
/**
* blkdev_get_zone_info - Get a single zone information from cached data
* @bdev: Target block device
* @sector: Sector contained by the target zone
* @zone: zone structure to return the zone information
*
* Description:
* Get the zone information for the zone containing @sector using the zone
* write plug of the target zone, if one exist, or the disk zone condition
* array otherwise. The zone condition may be reported as being
* the BLK_ZONE_COND_ACTIVE condition for a zone that is in the implicit
* open, explicit open or closed condition.
*
* Returns 0 on success and a negative error code on failure.
*/
int blkdev_get_zone_info(struct block_device *bdev, sector_t sector,
struct blk_zone *zone)
{
struct gendisk *disk = bdev->bd_disk;
sector_t zone_sectors = bdev_zone_sectors(bdev);
struct blk_zone_wplug *zwplug;
unsigned long flags;
u8 *zones_cond;
if (!bdev_is_zoned(bdev))
return -EOPNOTSUPP;
if (sector >= get_capacity(disk))
return -EINVAL;
memset(zone, 0, sizeof(*zone));
sector = bdev_zone_start(bdev, sector);
if (!blkdev_has_cached_report_zones(bdev))
return blkdev_report_zone_fallback(bdev, sector, zone);
rcu_read_lock();
zones_cond = rcu_dereference(disk->zones_cond);
if (!disk->zone_wplugs_hash || !zones_cond) {
rcu_read_unlock();
return blkdev_report_zone_fallback(bdev, sector, zone);
}
zone->cond = zones_cond[disk_zone_no(disk, sector)];
rcu_read_unlock();
zone->start = sector;
zone->len = zone_sectors;
/*
* If this is a conventional zone, we do not have a zone write plug and
* can report the zone immediately.
*/
if (zone->cond == BLK_ZONE_COND_NOT_WP) {
zone->type = BLK_ZONE_TYPE_CONVENTIONAL;
zone->capacity = zone_sectors;
zone->wp = ULLONG_MAX;
return 0;
}
/*
* This is a sequential write required zone. If the zone is read-only or
* offline, only set the zone write pointer to an invalid value and
* report the zone.
*/
zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
if (disk_zone_is_last(disk, zone))
zone->capacity = disk->last_zone_capacity;
else
zone->capacity = disk->zone_capacity;
if (zone->cond == BLK_ZONE_COND_READONLY ||
zone->cond == BLK_ZONE_COND_OFFLINE) {
zone->wp = ULLONG_MAX;
return 0;
}
/*
* If the zone does not have a zone write plug, it is either full or
* empty, as we otherwise would have a zone write plug for it. In this
* case, set the write pointer accordingly and report the zone.
* Otherwise, if we have a zone write plug, use it.
*/
zwplug = disk_get_zone_wplug(disk, sector);
if (!zwplug) {
if (zone->cond == BLK_ZONE_COND_FULL)
zone->wp = ULLONG_MAX;
else
zone->wp = sector;
return 0;
}
spin_lock_irqsave(&zwplug->lock, flags);
if (zwplug->flags & BLK_ZONE_WPLUG_NEED_WP_UPDATE) {
spin_unlock_irqrestore(&zwplug->lock, flags);
disk_put_zone_wplug(zwplug);
return blkdev_report_zone_fallback(bdev, sector, zone);
}
zone->cond = zwplug->cond;
zone->wp = sector + zwplug->wp_offset;
spin_unlock_irqrestore(&zwplug->lock, flags);
disk_put_zone_wplug(zwplug);
return 0;
}
EXPORT_SYMBOL_GPL(blkdev_get_zone_info);
/**
* blkdev_report_zones_cached - Get cached zones information
* @bdev: Target block device
* @sector: Sector from which to report zones
* @nr_zones: Maximum number of zones to report
* @cb: Callback function called for each reported zone
* @data: Private data for the callback function
*
* Description:
* Similar to blkdev_report_zones() but instead of calling into the low level
* device driver to get the zone report from the device, use
* blkdev_get_zone_info() to generate the report from the disk zone write
* plugs and zones condition array. Since calling this function without a
* callback does not make sense, @cb must be specified.
*/
int blkdev_report_zones_cached(struct block_device *bdev, sector_t sector,
unsigned int nr_zones, report_zones_cb cb, void *data)
{
struct gendisk *disk = bdev->bd_disk;
sector_t capacity = get_capacity(disk);
sector_t zone_sectors = bdev_zone_sectors(bdev);
unsigned int idx = 0;
struct blk_zone zone;
int ret;
if (!cb || !bdev_is_zoned(bdev) ||
WARN_ON_ONCE(!disk->fops->report_zones))
return -EOPNOTSUPP;
if (!nr_zones || sector >= capacity)
return 0;
if (!blkdev_has_cached_report_zones(bdev)) {
struct blk_report_zones_args args = {
.cb = cb,
.data = data,
.report_active = true,
};
return blkdev_do_report_zones(bdev, sector, nr_zones, &args);
}
for (sector = bdev_zone_start(bdev, sector);
sector < capacity && idx < nr_zones;
sector += zone_sectors, idx++) {
ret = blkdev_get_zone_info(bdev, sector, &zone);
if (ret)
return ret;
ret = cb(&zone, idx, data);
if (ret)
return ret;
}
return idx;
}
EXPORT_SYMBOL_GPL(blkdev_report_zones_cached);
static void blk_zone_reset_bio_endio(struct bio *bio)
{
struct gendisk *disk = bio->bi_bdev->bd_disk;
sector_t sector = bio->bi_iter.bi_sector;
struct blk_zone_wplug *zwplug;
/*
* If we have a zone write plug, set its write pointer offset to 0.
* This will abort all BIOs plugged for the target zone. It is fine as
* resetting zones while writes are still in-flight will result in the
* writes failing anyway.
*/
zwplug = disk_get_zone_wplug(disk, sector);
if (zwplug) {
unsigned long flags;
spin_lock_irqsave(&zwplug->lock, flags);
disk_zone_wplug_set_wp_offset(disk, zwplug, 0);
spin_unlock_irqrestore(&zwplug->lock, flags);
disk_put_zone_wplug(zwplug);
} else {
disk_zone_set_cond(disk, sector, BLK_ZONE_COND_EMPTY);
}
}
static void blk_zone_reset_all_bio_endio(struct bio *bio)
{
struct gendisk *disk = bio->bi_bdev->bd_disk;
sector_t capacity = get_capacity(disk);
struct blk_zone_wplug *zwplug;
unsigned long flags;
sector_t sector;
unsigned int i;
if (atomic_read(&disk->nr_zone_wplugs)) {
/* Update the condition of all zone write plugs. */
rcu_read_lock();
for (i = 0; i < disk_zone_wplugs_hash_size(disk); i++) {
hlist_for_each_entry_rcu(zwplug,
&disk->zone_wplugs_hash[i],
node) {
spin_lock_irqsave(&zwplug->lock, flags);
disk_zone_wplug_set_wp_offset(disk, zwplug, 0);
spin_unlock_irqrestore(&zwplug->lock, flags);
}
}
rcu_read_unlock();
}
/* Update the cached zone conditions. */
for (sector = 0; sector < capacity;
sector += bdev_zone_sectors(bio->bi_bdev))
disk_zone_set_cond(disk, sector, BLK_ZONE_COND_EMPTY);
clear_bit(GD_ZONE_APPEND_USED, &disk->state);
}
static void blk_zone_finish_bio_endio(struct bio *bio)
{
struct block_device *bdev = bio->bi_bdev;
struct gendisk *disk = bdev->bd_disk;
sector_t sector = bio->bi_iter.bi_sector;
struct blk_zone_wplug *zwplug;
/*
* If we have a zone write plug, set its write pointer offset to the
* zone size. This will abort all BIOs plugged for the target zone. It
* is fine as resetting zones while writes are still in-flight will
* result in the writes failing anyway.
*/
zwplug = disk_get_zone_wplug(disk, sector);
if (zwplug) {
unsigned long flags;
spin_lock_irqsave(&zwplug->lock, flags);
disk_zone_wplug_set_wp_offset(disk, zwplug,
bdev_zone_sectors(bdev));
spin_unlock_irqrestore(&zwplug->lock, flags);
disk_put_zone_wplug(zwplug);
} else {
disk_zone_set_cond(disk, sector, BLK_ZONE_COND_FULL);
}
}
void blk_zone_mgmt_bio_endio(struct bio *bio)
{
/* If the BIO failed, we have nothing to do. */
if (bio->bi_status != BLK_STS_OK)
return;
switch (bio_op(bio)) {
case REQ_OP_ZONE_RESET:
blk_zone_reset_bio_endio(bio);
return;
case REQ_OP_ZONE_RESET_ALL:
blk_zone_reset_all_bio_endio(bio);
return;
case REQ_OP_ZONE_FINISH:
blk_zone_finish_bio_endio(bio);
return;
default:
return;
}
}
static void disk_zone_wplug_schedule_work(struct gendisk *disk,
struct blk_zone_wplug *zwplug)
{
lockdep_assert_held(&zwplug->lock);
/*
* Schedule the submission of the next plugged BIO. Taking a reference
* to the zone write plug is required as the bio_work belongs to the
* plug, and thus we must ensure that the write plug does not go away
* while the work is being scheduled but has not run yet.
* blk_zone_wplug_bio_work() will release the reference we take here,
* and we also drop this reference if the work is already scheduled.
*/
WARN_ON_ONCE(!(zwplug->flags & BLK_ZONE_WPLUG_PLUGGED));
WARN_ON_ONCE(blk_queue_zoned_qd1_writes(disk->queue));
refcount_inc(&zwplug->ref);
if (!queue_work(disk->zone_wplugs_wq, &zwplug->bio_work))
disk_put_zone_wplug(zwplug);
}
static inline void disk_zone_wplug_add_bio(struct gendisk *disk,
struct blk_zone_wplug *zwplug,
struct bio *bio, unsigned int nr_segs)
{
/*
* Grab an extra reference on the BIO request queue usage counter.
* This reference will be reused to submit a request for the BIO for
* blk-mq devices and dropped when the BIO is failed and after
* it is issued in the case of BIO-based devices.
*/
percpu_ref_get(&bio->bi_bdev->bd_disk->queue->q_usage_counter);
/*
* The BIO is being plugged and thus will have to wait for the on-going
* write and for all other writes already plugged. So polling makes
* no sense.
*/
bio_clear_polled(bio);
/*
* Reuse the poll cookie field to store the number of segments when
* split to the hardware limits.
*/
bio->__bi_nr_segments = nr_segs;
/*
* We always receive BIOs after they are split and ready to be issued.
* The block layer passes the parts of a split BIO in order, and the
* user must also issue write sequentially. So simply add the new BIO
* at the tail of the list to preserve the sequential write order.
*/
bio_list_add(&zwplug->bio_list, bio);
trace_disk_zone_wplug_add_bio(zwplug->disk->queue, zwplug->zone_no,
bio->bi_iter.bi_sector, bio_sectors(bio));
/*
* If we are using the disk zone write plugs worker instead of the per
* zone write plug BIO work, add the zone write plug to the work list
* if it is not already there. Make sure to also get an extra reference
* on the zone write plug so that it does not go away until it is
* removed from the work list.
*/
if (blk_queue_zoned_qd1_writes(disk->queue)) {
spin_lock(&disk->zone_wplugs_list_lock);
if (list_empty(&zwplug->entry)) {
list_add_tail(&zwplug->entry, &disk->zone_wplugs_list);
refcount_inc(&zwplug->ref);
}
spin_unlock(&disk->zone_wplugs_list_lock);
}
}
/*
* Called from bio_attempt_back_merge() when a BIO was merged with a request.
*/
void blk_zone_write_plug_bio_merged(struct bio *bio)
{
struct gendisk *disk = bio->bi_bdev->bd_disk;
struct blk_zone_wplug *zwplug;
unsigned long flags;
/*
* If the BIO was already plugged, then we were called through
* blk_zone_write_plug_init_request() -> blk_attempt_bio_merge().
* For this case, we already hold a reference on the zone write plug for
* the BIO and blk_zone_write_plug_init_request() will handle the
* zone write pointer offset update.
*/
if (bio_flagged(bio, BIO_ZONE_WRITE_PLUGGING))
return;
bio_set_flag(bio, BIO_ZONE_WRITE_PLUGGING);
/*
* Get a reference on the zone write plug of the target zone and advance
* the zone write pointer offset. Given that this is a merge, we already
* have at least one request and one BIO referencing the zone write
* plug. So this should not fail.
*/
zwplug = disk_get_zone_wplug(disk, bio->bi_iter.bi_sector);
if (WARN_ON_ONCE(!zwplug))
return;
spin_lock_irqsave(&zwplug->lock, flags);
zwplug->wp_offset += bio_sectors(bio);
disk_zone_wplug_update_cond(disk, zwplug);
spin_unlock_irqrestore(&zwplug->lock, flags);
}
/*
* Attempt to merge plugged BIOs with a newly prepared request for a BIO that
* already went through zone write plugging (either a new BIO or one that was
* unplugged).
*/
void blk_zone_write_plug_init_request(struct request *req)
{
sector_t req_back_sector = blk_rq_pos(req) + blk_rq_sectors(req);
struct request_queue *q = req->q;
struct gendisk *disk = q->disk;
struct blk_zone_wplug *zwplug =
disk_get_zone_wplug(disk, blk_rq_pos(req));
unsigned long flags;
struct bio *bio;
if (WARN_ON_ONCE(!zwplug))
return;
/*
* Indicate that completion of this request needs to be handled with
* blk_zone_write_plug_finish_request(), which will drop the reference
* on the zone write plug we took above on entry to this function.
*/
req->rq_flags |= RQF_ZONE_WRITE_PLUGGING;
if (blk_queue_nomerges(q))
return;
/*
* Walk through the list of plugged BIOs to check if they can be merged
* into the back of the request.
*/
spin_lock_irqsave(&zwplug->lock, flags);
while (!disk_zone_wplug_is_full(disk, zwplug)) {
bio = bio_list_peek(&zwplug->bio_list);
if (!bio)
break;
if (bio->bi_iter.bi_sector != req_back_sector ||
!blk_rq_merge_ok(req, bio))
break;
WARN_ON_ONCE(bio_op(bio) != REQ_OP_WRITE_ZEROES &&
!bio->__bi_nr_segments);
bio_list_pop(&zwplug->bio_list);
if (bio_attempt_back_merge(req, bio, bio->__bi_nr_segments) !=
BIO_MERGE_OK) {
bio_list_add_head(&zwplug->bio_list, bio);
break;
}
/* Drop the reference taken by disk_zone_wplug_add_bio(). */
blk_queue_exit(q);
zwplug->wp_offset += bio_sectors(bio);
disk_zone_wplug_update_cond(disk, zwplug);
req_back_sector += bio_sectors(bio);
}
spin_unlock_irqrestore(&zwplug->lock, flags);
}
/*
* Check and prepare a BIO for submission by incrementing the write pointer
* offset of its zone write plug and changing zone append operations into
* regular write when zone append emulation is needed.
*/
static bool blk_zone_wplug_prepare_bio(struct blk_zone_wplug *zwplug,
struct bio *bio)
{
struct gendisk *disk = bio->bi_bdev->bd_disk;
lockdep_assert_held(&zwplug->lock);
/*
* If we lost track of the zone write pointer due to a write error,
* the user must either execute a report zones, reset the zone or finish
* the to recover a reliable write pointer position. Fail BIOs if the
* user did not do that as we cannot handle emulated zone append
* otherwise.
*/
if (zwplug->flags & BLK_ZONE_WPLUG_NEED_WP_UPDATE)
return false;
/*
* Check that the user is not attempting to write to a full zone.
* We know such BIO will fail, and that would potentially overflow our
* write pointer offset beyond the end of the zone.
*/
if (disk_zone_wplug_is_full(disk, zwplug))
return false;
if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
/*
* Use a regular write starting at the current write pointer.
* Similarly to native zone append operations, do not allow
* merging.
*/
bio->bi_opf &= ~REQ_OP_MASK;
bio->bi_opf |= REQ_OP_WRITE | REQ_NOMERGE;
bio->bi_iter.bi_sector += zwplug->wp_offset;
/*
* Remember that this BIO is in fact a zone append operation
* so that we can restore its operation code on completion.
*/
bio_set_flag(bio, BIO_EMULATES_ZONE_APPEND);
} else {
/*
* Check for non-sequential writes early as we know that BIOs
* with a start sector not unaligned to the zone write pointer
* will fail.
*/
if (bio_offset_from_zone_start(bio) != zwplug->wp_offset)
return false;
}
/* Advance the zone write pointer offset. */
zwplug->wp_offset += bio_sectors(bio);
disk_zone_wplug_update_cond(disk, zwplug);
return true;
}
static bool blk_zone_wplug_handle_write(struct bio *bio, unsigned int nr_segs)
{
struct gendisk *disk = bio->bi_bdev->bd_disk;
sector_t sector = bio->bi_iter.bi_sector;
struct blk_zone_wplug *zwplug;
gfp_t gfp_mask = GFP_NOIO;
unsigned long flags;
/*
* BIOs must be fully contained within a zone so that we use the correct
* zone write plug for the entire BIO. For blk-mq devices, the block
* layer should already have done any splitting required to ensure this
* and this BIO should thus not be straddling zone boundaries. For
* BIO-based devices, it is the responsibility of the driver to split
* the bio before submitting it.
*/
if (WARN_ON_ONCE(bio_straddles_zones(bio))) {
bio_io_error(bio);
return true;
}
/* Conventional zones do not need write plugging. */
if (!bdev_zone_is_seq(bio->bi_bdev, sector)) {
/* Zone append to conventional zones is not allowed. */
if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
bio_io_error(bio);
return true;
}
return false;
}
if (bio->bi_opf & REQ_NOWAIT)
gfp_mask = GFP_NOWAIT;
zwplug = disk_get_or_alloc_zone_wplug(disk, sector, gfp_mask);
if (!zwplug) {
if (bio->bi_opf & REQ_NOWAIT)
bio_wouldblock_error(bio);
else
bio_io_error(bio);
return true;
}
spin_lock_irqsave(&zwplug->lock, flags);
/*
* If we got a zone write plug marked as dead, then the user is issuing
* writes to a full zone, or without synchronizing with zone reset or
* zone finish operations. In such case, fail the BIO to signal this
* invalid usage.
*/
if (zwplug->flags & BLK_ZONE_WPLUG_DEAD) {
spin_unlock_irqrestore(&zwplug->lock, flags);
disk_put_zone_wplug(zwplug);
bio_io_error(bio);
return true;
}
/* Indicate that this BIO is being handled using zone write plugging. */
bio_set_flag(bio, BIO_ZONE_WRITE_PLUGGING);
/*
* Add REQ_NOWAIT BIOs to the plug list to ensure that we will not see a
* BLK_STS_AGAIN failure if we let the caller submit the BIO.
*/
if (bio->bi_opf & REQ_NOWAIT) {
bio->bi_opf &= ~REQ_NOWAIT;
goto queue_bio;
}
/*
* For rotational devices, we will use the gendisk zone write plugs
* work instead of the per zone write plug BIO work, so queue the BIO.
*/
if (blk_queue_zoned_qd1_writes(disk->queue))
goto queue_bio;
/* If the zone is already plugged, add the BIO to the BIO plug list. */
if (zwplug->flags & BLK_ZONE_WPLUG_PLUGGED)
goto queue_bio;
if (!blk_zone_wplug_prepare_bio(zwplug, bio)) {
spin_unlock_irqrestore(&zwplug->lock, flags);
bio_io_error(bio);
return true;
}
/* Otherwise, plug and let the caller submit the BIO. */
zwplug->flags |= BLK_ZONE_WPLUG_PLUGGED;
spin_unlock_irqrestore(&zwplug->lock, flags);
return false;
queue_bio:
disk_zone_wplug_add_bio(disk, zwplug, bio, nr_segs);
if (!(zwplug->flags & BLK_ZONE_WPLUG_PLUGGED)) {
zwplug->flags |= BLK_ZONE_WPLUG_PLUGGED;
if (blk_queue_zoned_qd1_writes(disk->queue))
wake_up_process(disk->zone_wplugs_worker);
else
disk_zone_wplug_schedule_work(disk, zwplug);
}
spin_unlock_irqrestore(&zwplug->lock, flags);
return true;
}
static void blk_zone_wplug_handle_native_zone_append(struct bio *bio)
{
struct gendisk *disk = bio->bi_bdev->bd_disk;
struct blk_zone_wplug *zwplug;
unsigned long flags;
if (!test_bit(GD_ZONE_APPEND_USED, &disk->state))
set_bit(GD_ZONE_APPEND_USED, &disk->state);
/*
* We have native support for zone append operations, so we are not
* going to handle @bio through plugging. However, we may already have a
* zone write plug for the target zone if that zone was previously
* partially written using regular writes. In such case, we risk leaving
* the plug in the disk hash table if the zone is fully written using
* zone append operations. Avoid this by removing the zone write plug.
*/
zwplug = disk_get_zone_wplug(disk, bio->bi_iter.bi_sector);
if (likely(!zwplug))
return;
spin_lock_irqsave(&zwplug->lock, flags);
/*
* We are about to remove the zone write plug. But if the user
* (mistakenly) has issued regular writes together with native zone
* append, we must aborts the writes as otherwise the plugged BIOs would
* not be executed by the plug BIO work as disk_get_zone_wplug() will
* return NULL after the plug is removed. Aborting the plugged write
* BIOs is consistent with the fact that these writes will most likely
* fail anyway as there is no ordering guarantees between zone append
* operations and regular write operations.
*/
if (!bio_list_empty(&zwplug->bio_list)) {
pr_warn_ratelimited("%s: zone %u: Invalid mix of zone append and regular writes\n",
disk->disk_name, zwplug->zone_no);
disk_zone_wplug_abort(zwplug);
}
disk_mark_zone_wplug_dead(zwplug);
spin_unlock_irqrestore(&zwplug->lock, flags);
disk_put_zone_wplug(zwplug);
}
static bool blk_zone_wplug_handle_zone_mgmt(struct bio *bio)
{
if (bio_op(bio) != REQ_OP_ZONE_RESET_ALL &&
!bdev_zone_is_seq(bio->bi_bdev, bio->bi_iter.bi_sector)) {
/*
* Zone reset and zone finish operations do not apply to
* conventional zones.
*/
bio_io_error(bio);
return true;
}
/*
* No-wait zone management BIOs do not make much sense as the callers
* issue these as blocking operations in most cases. To avoid issues
* with the BIO execution potentially failing with BLK_STS_AGAIN, warn
* about REQ_NOWAIT being set and ignore that flag.
*/
if (WARN_ON_ONCE(bio->bi_opf & REQ_NOWAIT))
bio->bi_opf &= ~REQ_NOWAIT;
return false;
}
/**
* blk_zone_plug_bio - Handle a zone write BIO with zone write plugging
* @bio: The BIO being submitted
* @nr_segs: The number of physical segments of @bio
*
* Handle write, write zeroes and zone append operations requiring emulation
* using zone write plugging.
*
* Return true whenever @bio execution needs to be delayed through the zone
* write plug. Otherwise, return false to let the submission path process
* @bio normally.
*/
bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs)
{
struct block_device *bdev = bio->bi_bdev;
if (WARN_ON_ONCE(!bdev->bd_disk->zone_wplugs_hash))
return false;
/*
* Regular writes and write zeroes need to be handled through the target
* zone write plug. This includes writes with REQ_FUA | REQ_PREFLUSH
* which may need to go through the flush machinery depending on the
* target device capabilities. Plugging such writes is fine as the flush
* machinery operates at the request level, below the plug, and
* completion of the flush sequence will go through the regular BIO
* completion, which will handle zone write plugging.
* Zone append operations for devices that requested emulation must
* also be plugged so that these BIOs can be changed into regular
* write BIOs.
* Zone reset, reset all and finish commands need special treatment
* to correctly track the write pointer offset of zones. These commands
* are not plugged as we do not need serialization with write
* operations. It is the responsibility of the user to not issue reset
* and finish commands when write operations are in flight.
*/
switch (bio_op(bio)) {
case REQ_OP_ZONE_APPEND:
if (!bdev_emulates_zone_append(bdev)) {
blk_zone_wplug_handle_native_zone_append(bio);
return false;
}
fallthrough;
case REQ_OP_WRITE:
case REQ_OP_WRITE_ZEROES:
return blk_zone_wplug_handle_write(bio, nr_segs);
case REQ_OP_ZONE_RESET:
case REQ_OP_ZONE_FINISH:
case REQ_OP_ZONE_RESET_ALL:
return blk_zone_wplug_handle_zone_mgmt(bio);
default:
return false;
}
return false;
}
EXPORT_SYMBOL_GPL(blk_zone_plug_bio);
static void disk_zone_wplug_unplug_bio(struct gendisk *disk,
struct blk_zone_wplug *zwplug)
{
unsigned long flags;
spin_lock_irqsave(&zwplug->lock, flags);
/*
* For rotational devices, signal the BIO completion to the zone write
* plug work. Otherwise, schedule submission of the next plugged BIO
* if we have one.
*/
if (bio_list_empty(&zwplug->bio_list))
zwplug->flags &= ~BLK_ZONE_WPLUG_PLUGGED;
if (blk_queue_zoned_qd1_writes(disk->queue))
complete(&disk->zone_wplugs_worker_bio_done);
else if (!bio_list_empty(&zwplug->bio_list))
disk_zone_wplug_schedule_work(disk, zwplug);
if (!zwplug->wp_offset || disk_zone_wplug_is_full(disk, zwplug))
disk_mark_zone_wplug_dead(zwplug);
spin_unlock_irqrestore(&zwplug->lock, flags);
}
void blk_zone_append_update_request_bio(struct request *rq, struct bio *bio)
{
/*
* For zone append requests, the request sector indicates the location
* at which the BIO data was written. Return this value to the BIO
* issuer through the BIO iter sector.
* For plugged zone writes, which include emulated zone append, we need
* the original BIO sector so that blk_zone_write_plug_bio_endio() can
* lookup the zone write plug.
*/
bio->bi_iter.bi_sector = rq->__sector;
trace_blk_zone_append_update_request_bio(rq);
}
void blk_zone_write_plug_bio_endio(struct bio *bio)
{
struct gendisk *disk = bio->bi_bdev->bd_disk;
struct blk_zone_wplug *zwplug =
disk_get_zone_wplug(disk, bio->bi_iter.bi_sector);
unsigned long flags;
if (WARN_ON_ONCE(!zwplug))
return;
/* Make sure we do not see this BIO again by clearing the plug flag. */
bio_clear_flag(bio, BIO_ZONE_WRITE_PLUGGING);
/*
* If this is a regular write emulating a zone append operation,
* restore the original operation code.
*/
if (bio_flagged(bio, BIO_EMULATES_ZONE_APPEND)) {
bio->bi_opf &= ~REQ_OP_MASK;
bio->bi_opf |= REQ_OP_ZONE_APPEND;
bio_clear_flag(bio, BIO_EMULATES_ZONE_APPEND);
}
/*
* If the BIO failed, abort all plugged BIOs and mark the plug as
* needing a write pointer update.
*/
if (bio->bi_status != BLK_STS_OK) {
spin_lock_irqsave(&zwplug->lock, flags);
disk_zone_wplug_abort(zwplug);
zwplug->flags |= BLK_ZONE_WPLUG_NEED_WP_UPDATE;
spin_unlock_irqrestore(&zwplug->lock, flags);
}
/* Drop the reference we took when the BIO was issued. */
disk_put_zone_wplug(zwplug);
/*
* For BIO-based devices, blk_zone_write_plug_finish_request()
* is not called. So we need to schedule execution of the next
* plugged BIO here.
*/
if (bdev_test_flag(bio->bi_bdev, BD_HAS_SUBMIT_BIO))
disk_zone_wplug_unplug_bio(disk, zwplug);
/* Drop the reference we took when entering this function. */
disk_put_zone_wplug(zwplug);
}
void blk_zone_write_plug_finish_request(struct request *req)
{
struct gendisk *disk = req->q->disk;
struct blk_zone_wplug *zwplug;
zwplug = disk_get_zone_wplug(disk, req->__sector);
if (WARN_ON_ONCE(!zwplug))
return;
req->rq_flags &= ~RQF_ZONE_WRITE_PLUGGING;
/*
* Drop the reference we took when the request was initialized in
* blk_zone_write_plug_init_request().
*/
disk_put_zone_wplug(zwplug);
disk_zone_wplug_unplug_bio(disk, zwplug);
/* Drop the reference we took when entering this function. */
disk_put_zone_wplug(zwplug);
}
static bool disk_zone_wplug_submit_bio(struct gendisk *disk,
struct blk_zone_wplug *zwplug)
{
struct block_device *bdev;
unsigned long flags;
struct bio *bio;
bool prepared;
/*
* Submit the next plugged BIO. If we do not have any, clear
* the plugged flag.
*/
again:
spin_lock_irqsave(&zwplug->lock, flags);
bio = bio_list_pop(&zwplug->bio_list);
if (!bio) {
zwplug->flags &= ~BLK_ZONE_WPLUG_PLUGGED;
spin_unlock_irqrestore(&zwplug->lock, flags);
return false;
}
trace_blk_zone_wplug_bio(zwplug->disk->queue, zwplug->zone_no,
bio->bi_iter.bi_sector, bio_sectors(bio));
prepared = blk_zone_wplug_prepare_bio(zwplug, bio);
spin_unlock_irqrestore(&zwplug->lock, flags);
if (!prepared) {
blk_zone_wplug_bio_io_error(zwplug, bio);
goto again;
}
/*
* blk-mq devices will reuse the extra reference on the request queue
* usage counter we took when the BIO was plugged, but the submission
* path for BIO-based devices will not do that. So drop this extra
* reference here.
*/
if (blk_queue_zoned_qd1_writes(disk->queue))
reinit_completion(&disk->zone_wplugs_worker_bio_done);
bdev = bio->bi_bdev;
if (bdev_test_flag(bdev, BD_HAS_SUBMIT_BIO)) {
bdev->bd_disk->fops->submit_bio(bio);
blk_queue_exit(bdev->bd_disk->queue);
} else {
blk_mq_submit_bio(bio);
}
return true;
}
static struct blk_zone_wplug *disk_get_zone_wplugs_work(struct gendisk *disk)
{
struct blk_zone_wplug *zwplug;
spin_lock_irq(&disk->zone_wplugs_list_lock);
zwplug = list_first_entry_or_null(&disk->zone_wplugs_list,
struct blk_zone_wplug, entry);
if (zwplug)
list_del_init(&zwplug->entry);
spin_unlock_irq(&disk->zone_wplugs_list_lock);
return zwplug;
}
static int disk_zone_wplugs_worker(void *data)
{
struct gendisk *disk = data;
struct blk_zone_wplug *zwplug;
unsigned int noio_flag;
noio_flag = memalloc_noio_save();
set_user_nice(current, MIN_NICE);
set_freezable();
for (;;) {
set_current_state(TASK_INTERRUPTIBLE | TASK_FREEZABLE);
zwplug = disk_get_zone_wplugs_work(disk);
if (zwplug) {
/*
* Process all BIOs of this zone write plug and then
* drop the reference we took when adding the zone write
* plug to the active list.
*/
set_current_state(TASK_RUNNING);
while (disk_zone_wplug_submit_bio(disk, zwplug))
blk_wait_io(&disk->zone_wplugs_worker_bio_done);
disk_put_zone_wplug(zwplug);
continue;
}
/*
* Only sleep if nothing sets the state to running. Else check
* for zone write plugs work again as a newly submitted BIO
* might have added a zone write plug to the work list.
*/
if (get_current_state() == TASK_RUNNING) {
try_to_freeze();
} else {
if (kthread_should_stop()) {
set_current_state(TASK_RUNNING);
break;
}
schedule();
}
}
WARN_ON_ONCE(!list_empty(&disk->zone_wplugs_list));
memalloc_noio_restore(noio_flag);
return 0;
}
void disk_init_zone_resources(struct gendisk *disk)
{
spin_lock_init(&disk->zone_wplugs_hash_lock);
spin_lock_init(&disk->zone_wplugs_list_lock);
INIT_LIST_HEAD(&disk->zone_wplugs_list);
init_completion(&disk->zone_wplugs_worker_bio_done);
}
/*
* For the size of a disk zone write plug hash table, use the size of the
* zone write plug mempool, which is the maximum of the disk open zones and
* active zones limits. But do not exceed 4KB (512 hlist head entries), that is,
* 9 bits. For a disk that has no limits, mempool size defaults to 128.
*/
#define BLK_ZONE_WPLUG_MAX_HASH_BITS 9
#define BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE 128
static int disk_alloc_zone_resources(struct gendisk *disk,
unsigned int pool_size)
{
unsigned int i;
int ret = -ENOMEM;
atomic_set(&disk->nr_zone_wplugs, 0);
disk->zone_wplugs_hash_bits =
min(ilog2(pool_size) + 1, BLK_ZONE_WPLUG_MAX_HASH_BITS);
disk->zone_wplugs_hash =
kzalloc_objs(struct hlist_head,
disk_zone_wplugs_hash_size(disk));
if (!disk->zone_wplugs_hash)
return -ENOMEM;
for (i = 0; i < disk_zone_wplugs_hash_size(disk); i++)
INIT_HLIST_HEAD(&disk->zone_wplugs_hash[i]);
disk->zone_wplugs_pool = mempool_create_kmalloc_pool(pool_size,
sizeof(struct blk_zone_wplug));
if (!disk->zone_wplugs_pool)
goto free_hash;
disk->zone_wplugs_wq =
alloc_workqueue("%s_zwplugs", WQ_MEM_RECLAIM | WQ_HIGHPRI,
pool_size, disk->disk_name);
if (!disk->zone_wplugs_wq)
goto destroy_pool;
disk->zone_wplugs_worker =
kthread_create(disk_zone_wplugs_worker, disk,
"%s_zwplugs_worker", disk->disk_name);
if (IS_ERR(disk->zone_wplugs_worker)) {
ret = PTR_ERR(disk->zone_wplugs_worker);
disk->zone_wplugs_worker = NULL;
goto destroy_wq;
}
wake_up_process(disk->zone_wplugs_worker);
return 0;
destroy_wq:
destroy_workqueue(disk->zone_wplugs_wq);
disk->zone_wplugs_wq = NULL;
destroy_pool:
mempool_destroy(disk->zone_wplugs_pool);
disk->zone_wplugs_pool = NULL;
free_hash:
kfree(disk->zone_wplugs_hash);
disk->zone_wplugs_hash = NULL;
disk->zone_wplugs_hash_bits = 0;
return ret;
}
static void disk_destroy_zone_wplugs_hash_table(struct gendisk *disk)
{
struct blk_zone_wplug *zwplug;
unsigned int i;
if (!disk->zone_wplugs_hash)
return;
/* Free all the zone write plugs we have. */
for (i = 0; i < disk_zone_wplugs_hash_size(disk); i++) {
while (!hlist_empty(&disk->zone_wplugs_hash[i])) {
zwplug = hlist_entry(disk->zone_wplugs_hash[i].first,
struct blk_zone_wplug, node);
spin_lock_irq(&zwplug->lock);
disk_mark_zone_wplug_dead(zwplug);
spin_unlock_irq(&zwplug->lock);
}
}
WARN_ON_ONCE(atomic_read(&disk->nr_zone_wplugs));
kfree(disk->zone_wplugs_hash);
disk->zone_wplugs_hash = NULL;
disk->zone_wplugs_hash_bits = 0;
/*
* Wait for the zone write plugs to be RCU-freed before destroying the
* mempool.
*/
rcu_barrier();
mempool_destroy(disk->zone_wplugs_pool);
disk->zone_wplugs_pool = NULL;
}
static void disk_set_zones_cond_array(struct gendisk *disk, u8 *zones_cond)
{
unsigned long flags;
spin_lock_irqsave(&disk->zone_wplugs_hash_lock, flags);
zones_cond = rcu_replace_pointer(disk->zones_cond, zones_cond,
lockdep_is_held(&disk->zone_wplugs_hash_lock));
spin_unlock_irqrestore(&disk->zone_wplugs_hash_lock, flags);
kfree_rcu_mightsleep(zones_cond);
}
void disk_free_zone_resources(struct gendisk *disk)
{
if (disk->zone_wplugs_worker)
kthread_stop(disk->zone_wplugs_worker);
WARN_ON_ONCE(!list_empty(&disk->zone_wplugs_list));
if (disk->zone_wplugs_wq) {
destroy_workqueue(disk->zone_wplugs_wq);
disk->zone_wplugs_wq = NULL;
}
disk_destroy_zone_wplugs_hash_table(disk);
disk_set_zones_cond_array(disk, NULL);
disk->zone_capacity = 0;
disk->last_zone_capacity = 0;
disk->nr_zones = 0;
}
struct blk_revalidate_zone_args {
struct gendisk *disk;
u8 *zones_cond;
unsigned int nr_zones;
unsigned int nr_conv_zones;
unsigned int zone_capacity;
unsigned int last_zone_capacity;
sector_t sector;
};
static int disk_revalidate_zone_resources(struct gendisk *disk,
struct blk_revalidate_zone_args *args)
{
struct queue_limits *lim = &disk->queue->limits;
unsigned int pool_size;
args->disk = disk;
args->nr_zones =
DIV_ROUND_UP_ULL(get_capacity(disk), lim->chunk_sectors);
/* Cached zone conditions: 1 byte per zone */
args->zones_cond = kzalloc(args->nr_zones, GFP_NOIO);
if (!args->zones_cond)
return -ENOMEM;
if (!disk_need_zone_resources(disk))
return 0;
/*
* If the device has no limit on the maximum number of open and active
* zones, use BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE.
*/
pool_size = max(lim->max_open_zones, lim->max_active_zones);
if (!pool_size)
pool_size =
min(BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE, args->nr_zones);
if (!disk->zone_wplugs_hash)
return disk_alloc_zone_resources(disk, pool_size);
return 0;
}
/*
* Update the disk zone resources information and device queue limits.
* The disk queue is frozen when this is executed.
*/
static int disk_update_zone_resources(struct gendisk *disk,
struct blk_revalidate_zone_args *args)
{
struct request_queue *q = disk->queue;
unsigned int nr_seq_zones;
unsigned int pool_size, memflags;
struct queue_limits lim;
int ret = 0;
lim = queue_limits_start_update(q);
memflags = blk_mq_freeze_queue(q);
disk->nr_zones = args->nr_zones;
if (args->nr_conv_zones >= disk->nr_zones) {
queue_limits_cancel_update(q);
pr_warn("%s: Invalid number of conventional zones %u / %u\n",
disk->disk_name, args->nr_conv_zones, disk->nr_zones);
ret = -ENODEV;
goto unfreeze;
}
disk->zone_capacity = args->zone_capacity;
disk->last_zone_capacity = args->last_zone_capacity;
disk_set_zones_cond_array(disk, args->zones_cond);
/*
* Some devices can advertise zone resource limits that are larger than
* the number of sequential zones of the zoned block device, e.g. a
* small ZNS namespace. For such case, assume that the zoned device has
* no zone resource limits.
*/
nr_seq_zones = disk->nr_zones - args->nr_conv_zones;
if (lim.max_open_zones >= nr_seq_zones)
lim.max_open_zones = 0;
if (lim.max_active_zones >= nr_seq_zones)
lim.max_active_zones = 0;
if (!disk->zone_wplugs_pool)
goto commit;
/*
* If the device has no limit on the maximum number of open and active
* zones, set its max open zone limit to the mempool size to indicate
* to the user that there is a potential performance impact due to
* dynamic zone write plug allocation when simultaneously writing to
* more zones than the size of the mempool.
*/
pool_size = max(lim.max_open_zones, lim.max_active_zones);
if (!pool_size)
pool_size = min(BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE, nr_seq_zones);
mempool_resize(disk->zone_wplugs_pool, pool_size);
if (!lim.max_open_zones && !lim.max_active_zones) {
if (pool_size < nr_seq_zones)
lim.max_open_zones = pool_size;
else
lim.max_open_zones = 0;
}
commit:
ret = queue_limits_commit_update(q, &lim);
unfreeze:
if (ret)
disk_free_zone_resources(disk);
blk_mq_unfreeze_queue(q, memflags);
return ret;
}
static int blk_revalidate_zone_cond(struct blk_zone *zone, unsigned int idx,
struct blk_revalidate_zone_args *args)
{
enum blk_zone_cond cond = zone->cond;
/* Check that the zone condition is consistent with the zone type. */
switch (cond) {
case BLK_ZONE_COND_NOT_WP:
if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL)
goto invalid_condition;
break;
case BLK_ZONE_COND_IMP_OPEN:
case BLK_ZONE_COND_EXP_OPEN:
case BLK_ZONE_COND_CLOSED:
case BLK_ZONE_COND_EMPTY:
case BLK_ZONE_COND_FULL:
case BLK_ZONE_COND_OFFLINE:
case BLK_ZONE_COND_READONLY:
if (zone->type != BLK_ZONE_TYPE_SEQWRITE_REQ)
goto invalid_condition;
break;
default:
pr_warn("%s: Invalid zone condition 0x%X\n",
args->disk->disk_name, cond);
return -ENODEV;
}
blk_zone_set_cond(args->zones_cond, idx, cond);
return 0;
invalid_condition:
pr_warn("%s: Invalid zone condition 0x%x for type 0x%x\n",
args->disk->disk_name, cond, zone->type);
return -ENODEV;
}
static int blk_revalidate_conv_zone(struct blk_zone *zone, unsigned int idx,
struct blk_revalidate_zone_args *args)
{
struct gendisk *disk = args->disk;
if (zone->capacity != zone->len) {
pr_warn("%s: Invalid conventional zone capacity\n",
disk->disk_name);
return -ENODEV;
}
if (disk_zone_is_last(disk, zone))
args->last_zone_capacity = zone->capacity;
args->nr_conv_zones++;
return 0;
}
static int blk_revalidate_seq_zone(struct blk_zone *zone, unsigned int idx,
struct blk_revalidate_zone_args *args)
{
struct gendisk *disk = args->disk;
struct blk_zone_wplug *zwplug;
unsigned int wp_offset;
/*
* Remember the capacity of the first sequential zone and check
* if it is constant for all zones, ignoring the last zone as it can be
* smaller.
*/
if (!args->zone_capacity)
args->zone_capacity = zone->capacity;
if (disk_zone_is_last(disk, zone)) {
args->last_zone_capacity = zone->capacity;
} else if (zone->capacity != args->zone_capacity) {
pr_warn("%s: Invalid variable zone capacity\n",
disk->disk_name);
return -ENODEV;
}
/*
* If the device needs zone append emulation, we need to track the
* write pointer of all zones that are not empty nor full. So make sure
* we have a zone write plug for such zone if the device has a zone
* write plug hash table.
*/
if (!disk->zone_wplugs_hash)
return 0;
wp_offset = disk_zone_wplug_sync_wp_offset(disk, zone);
if (!wp_offset || wp_offset >= zone->capacity)
return 0;
zwplug = disk_get_or_alloc_zone_wplug(disk, zone->wp, GFP_NOIO);
if (!zwplug)
return -ENOMEM;
disk_put_zone_wplug(zwplug);
return 0;
}
/*
* Helper function to check the validity of zones of a zoned block device.
*/
static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx,
void *data)
{
struct blk_revalidate_zone_args *args = data;
struct gendisk *disk = args->disk;
sector_t zone_sectors = disk->queue->limits.chunk_sectors;
int ret;
/* Check for bad zones and holes in the zone report */
if (zone->start != args->sector) {
pr_warn("%s: Zone gap at sectors %llu..%llu\n",
disk->disk_name, args->sector, zone->start);
return -ENODEV;
}
if (zone->start >= get_capacity(disk) || !zone->len) {
pr_warn("%s: Invalid zone start %llu, length %llu\n",
disk->disk_name, zone->start, zone->len);
return -ENODEV;
}
/*
* All zones must have the same size, with the exception on an eventual
* smaller last zone.
*/
if (!disk_zone_is_last(disk, zone)) {
if (zone->len != zone_sectors) {
pr_warn("%s: Invalid zoned device with non constant zone size\n",
disk->disk_name);
return -ENODEV;
}
} else if (zone->len > zone_sectors) {
pr_warn("%s: Invalid zoned device with larger last zone size\n",
disk->disk_name);
return -ENODEV;
}
if (!zone->capacity || zone->capacity > zone->len) {
pr_warn("%s: Invalid zone capacity\n",
disk->disk_name);
return -ENODEV;
}
/* Check zone condition */
ret = blk_revalidate_zone_cond(zone, idx, args);
if (ret)
return ret;
/* Check zone type */
switch (zone->type) {
case BLK_ZONE_TYPE_CONVENTIONAL:
ret = blk_revalidate_conv_zone(zone, idx, args);
break;
case BLK_ZONE_TYPE_SEQWRITE_REQ:
ret = blk_revalidate_seq_zone(zone, idx, args);
break;
case BLK_ZONE_TYPE_SEQWRITE_PREF:
default:
pr_warn("%s: Invalid zone type 0x%x at sectors %llu\n",
disk->disk_name, (int)zone->type, zone->start);
ret = -ENODEV;
}
if (!ret)
args->sector += zone->len;
return ret;
}
/**
* blk_revalidate_disk_zones - (re)allocate and initialize zone write plugs
* @disk: Target disk
*
* Helper function for low-level device drivers to check, (re) allocate and
* initialize resources used for managing zoned disks. This function should
* normally be called by blk-mq based drivers when a zoned gendisk is probed
* and when the zone configuration of the gendisk changes (e.g. after a format).
* Before calling this function, the device driver must already have set the
* device zone size (chunk_sector limit) and the max zone append limit.
* BIO based drivers can also use this function as long as the device queue
* can be safely frozen.
*/
int blk_revalidate_disk_zones(struct gendisk *disk)
{
struct request_queue *q = disk->queue;
sector_t zone_sectors = q->limits.chunk_sectors;
sector_t capacity = get_capacity(disk);
struct blk_revalidate_zone_args args = { };
unsigned int memflags, noio_flag;
struct blk_report_zones_args rep_args = {
.cb = blk_revalidate_zone_cb,
.data = &args,
};
int ret = -ENOMEM;
if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
return -EIO;
if (!capacity)
return -ENODEV;
/*
* Checks that the device driver indicated a valid zone size and that
* the max zone append limit is set.
*/
if (!zone_sectors || !is_power_of_2(zone_sectors)) {
pr_warn("%s: Invalid non power of two zone size (%llu)\n",
disk->disk_name, zone_sectors);
return -ENODEV;
}
/*
* Ensure that all memory allocations in this context are done as if
* GFP_NOIO was specified.
*/
noio_flag = memalloc_noio_save();
ret = disk_revalidate_zone_resources(disk, &args);
if (ret) {
memalloc_noio_restore(noio_flag);
return ret;
}
ret = disk->fops->report_zones(disk, 0, UINT_MAX, &rep_args);
if (!ret) {
pr_warn("%s: No zones reported\n", disk->disk_name);
ret = -ENODEV;
}
memalloc_noio_restore(noio_flag);
/*
* If zones where reported, make sure that the entire disk capacity
* has been checked.
*/
if (ret > 0 && args.sector != capacity) {
pr_warn("%s: Missing zones from sector %llu\n",
disk->disk_name, args.sector);
ret = -ENODEV;
}
if (ret > 0)
return disk_update_zone_resources(disk, &args);
pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
memflags = blk_mq_freeze_queue(q);
disk_free_zone_resources(disk);
blk_mq_unfreeze_queue(q, memflags);
return ret;
}
EXPORT_SYMBOL_GPL(blk_revalidate_disk_zones);
/**
* blk_zone_issue_zeroout - zero-fill a block range in a zone
* @bdev: blockdev to write
* @sector: start sector
* @nr_sects: number of sectors to write
* @gfp_mask: memory allocation flags (for bio_alloc)
*
* Description:
* Zero-fill a block range in a zone (@sector must be equal to the zone write
* pointer), handling potential errors due to the (initially unknown) lack of
* hardware offload (See blkdev_issue_zeroout()).
*/
int blk_zone_issue_zeroout(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask)
{
struct gendisk *disk = bdev->bd_disk;
int ret;
if (WARN_ON_ONCE(!bdev_is_zoned(bdev)))
return -EIO;
ret = blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask,
BLKDEV_ZERO_NOFALLBACK);
if (ret != -EOPNOTSUPP)
return ret;
/*
* The failed call to blkdev_issue_zeroout() advanced the zone write
* pointer. Undo this using a report zone to update the zone write
* pointer to the correct current value.
*/
ret = disk->fops->report_zones(disk, sector, 1, NULL);
if (ret != 1)
return ret < 0 ? ret : -EIO;
/*
* Retry without BLKDEV_ZERO_NOFALLBACK to force the fallback to a
* regular write with zero-pages.
*/
return blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask, 0);
}
EXPORT_SYMBOL_GPL(blk_zone_issue_zeroout);
#ifdef CONFIG_BLK_DEBUG_FS
static void queue_zone_wplug_show(struct blk_zone_wplug *zwplug,
struct seq_file *m)
{
unsigned int zwp_wp_offset, zwp_flags;
unsigned int zwp_zone_no, zwp_ref;
unsigned int zwp_bio_list_size;
enum blk_zone_cond zwp_cond;
unsigned long flags;
spin_lock_irqsave(&zwplug->lock, flags);
zwp_zone_no = zwplug->zone_no;
zwp_flags = zwplug->flags;
zwp_ref = refcount_read(&zwplug->ref);
zwp_cond = zwplug->cond;
zwp_wp_offset = zwplug->wp_offset;
zwp_bio_list_size = bio_list_size(&zwplug->bio_list);
spin_unlock_irqrestore(&zwplug->lock, flags);
seq_printf(m,
"Zone no: %u, flags: 0x%x, ref: %u, cond: %s, wp ofst: %u, pending BIO: %u\n",
zwp_zone_no, zwp_flags, zwp_ref, blk_zone_cond_str(zwp_cond),
zwp_wp_offset, zwp_bio_list_size);
}
int queue_zone_wplugs_show(void *data, struct seq_file *m)
{
struct request_queue *q = data;
struct gendisk *disk = q->disk;
struct blk_zone_wplug *zwplug;
unsigned int i;
if (!disk->zone_wplugs_hash)
return 0;
rcu_read_lock();
for (i = 0; i < disk_zone_wplugs_hash_size(disk); i++)
hlist_for_each_entry_rcu(zwplug, &disk->zone_wplugs_hash[i],
node)
queue_zone_wplug_show(zwplug, m);
rcu_read_unlock();
return 0;
}
#endif
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