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blk-zoned.c
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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/module.h>
#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/sched/mm.h>
#include <linux/spinlock.h>
#include <linux/atomic.h>
#include <linux/mempool.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),
};
#undef ZONE_COND_NAME
/*
* Per-zone write plug.
* @node: hlist_node structure for managing the plug using a hash table.
* @link: To list the plug in the zone write plug error list of the disk.
* @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).
* @lock: Spinlock to atomically manipulate the plug.
* @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.
* @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.
*/
struct blk_zone_wplug {
struct hlist_node node;
struct list_head link;
atomic_t ref;
spinlock_t lock;
unsigned int flags;
unsigned int zone_no;
unsigned int wp_offset;
struct bio_list bio_list;
struct work_struct bio_work;
struct rcu_head rcu_head;
struct gendisk *disk;
};
/*
* 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_ERROR: Indicates that a write error happened which will be
* recovered with a report zone to update the zone write pointer offset.
* - BLK_ZONE_WPLUG_UNHASHED: Indicates that the zone write plug was removed
* from the disk hash table and that the initial reference to the zone
* write plug set when the plug was first added to the hash table has been
* dropped. This flag is set when a zone is reset, finished or become full,
* to prevent new references to the zone write plug to be taken for
* newly incoming BIOs. A zone write plug flagged with this flag will be
* freed once all remaining references from BIOs or functions are dropped.
*/
#define BLK_ZONE_WPLUG_PLUGGED (1U << 0)
#define BLK_ZONE_WPLUG_ERROR (1U << 1)
#define BLK_ZONE_WPLUG_UNHASHED (1U << 2)
#define BLK_ZONE_WPLUG_BUSY (BLK_ZONE_WPLUG_PLUGGED | BLK_ZONE_WPLUG_ERROR)
/**
* blk_zone_cond_str - Return string XXX in BLK_ZONE_COND_XXX.
* @zone_cond: BLK_ZONE_COND_XXX.
*
* Description: Centralize block layer function to convert BLK_ZONE_COND_XXX
* into string format. Useful in the debugging and tracing zone conditions. For
* invalid BLK_ZONE_COND_XXX it returns string "UNKNOWN".
*/
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);
/**
* bdev_nr_zones - Get number of zones
* @bdev: Target device
*
* Return the total number of zones of a zoned block device. For a block
* device without zone capabilities, the number of zones is always 0.
*/
unsigned int bdev_nr_zones(struct block_device *bdev)
{
sector_t zone_sectors = bdev_zone_sectors(bdev);
if (!bdev_is_zoned(bdev))
return 0;
return (bdev_nr_sectors(bdev) + zone_sectors - 1) >>
ilog2(zone_sectors);
}
EXPORT_SYMBOL_GPL(bdev_nr_zones);
/**
* 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 gendisk *disk = bdev->bd_disk;
sector_t capacity = get_capacity(disk);
if (!bdev_is_zoned(bdev) || WARN_ON_ONCE(!disk->fops->report_zones))
return -EOPNOTSUPP;
if (!nr_zones || sector >= capacity)
return 0;
return disk->fops->report_zones(disk, sector, nr_zones, cb, data);
}
EXPORT_SYMBOL_GPL(blkdev_report_zones);
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);
}
static int blk_zone_need_reset_cb(struct blk_zone *zone, unsigned int idx,
void *data)
{
/*
* For an all-zones reset, ignore conventional, empty, read-only
* and offline zones.
*/
switch (zone->cond) {
case BLK_ZONE_COND_NOT_WP:
case BLK_ZONE_COND_EMPTY:
case BLK_ZONE_COND_READONLY:
case BLK_ZONE_COND_OFFLINE:
return 0;
default:
set_bit(idx, (unsigned long *)data);
return 0;
}
}
static int blkdev_zone_reset_all_emulated(struct block_device *bdev)
{
struct gendisk *disk = bdev->bd_disk;
sector_t capacity = bdev_nr_sectors(bdev);
sector_t zone_sectors = bdev_zone_sectors(bdev);
unsigned long *need_reset;
struct bio *bio = NULL;
sector_t sector = 0;
int ret;
need_reset = blk_alloc_zone_bitmap(disk->queue->node, disk->nr_zones);
if (!need_reset)
return -ENOMEM;
ret = disk->fops->report_zones(disk, 0, disk->nr_zones,
blk_zone_need_reset_cb, need_reset);
if (ret < 0)
goto out_free_need_reset;
ret = 0;
while (sector < capacity) {
if (!test_bit(disk_zone_no(disk, sector), need_reset)) {
sector += zone_sectors;
continue;
}
bio = blk_next_bio(bio, bdev, 0, REQ_OP_ZONE_RESET | 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();
}
if (bio) {
ret = submit_bio_wait(bio);
bio_put(bio);
}
out_free_need_reset:
kfree(need_reset);
return ret;
}
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);
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)
{
struct request_queue *q = bdev_get_queue(bdev);
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,
* REQ_OP_ZONE_RESET_ALL can be used with devices supporting this
* command. For other devices, we emulate this command behavior by
* identifying the zones needing a reset.
*/
if (op == REQ_OP_ZONE_RESET && sector == 0 && nr_sectors == capacity) {
if (!blk_queue_zone_resetall(q))
return blkdev_zone_reset_all_emulated(bdev);
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();
}
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;
}
/*
* BLKREPORTZONE 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);
ret = blkdev_report_zones(bdev, rep.sector, rep.nr_zones,
blkdev_copy_zone_to_user, &args);
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. */
filemap_invalidate_lock(bdev->bd_inode->i_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_inode->i_mapping);
return ret;
}
static inline bool disk_zone_is_conv(struct gendisk *disk, sector_t sector)
{
if (!disk->conv_zones_bitmap)
return false;
return test_bit(disk_zone_no(disk, sector), disk->conv_zones_bitmap);
}
static bool disk_insert_zone_wplug(struct gendisk *disk,
struct blk_zone_wplug *zwplug)
{
struct blk_zone_wplug *zwplg;
unsigned long flags;
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_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_lock, flags);
return false;
}
}
hlist_add_head_rcu(&zwplug->node, &disk->zone_wplugs_hash[idx]);
spin_unlock_irqrestore(&disk->zone_wplugs_lock, flags);
return true;
}
static void disk_remove_zone_wplug(struct gendisk *disk,
struct blk_zone_wplug *zwplug)
{
unsigned long flags;
spin_lock_irqsave(&disk->zone_wplugs_lock, flags);
zwplug->flags |= BLK_ZONE_WPLUG_UNHASHED;
atomic_dec(&zwplug->ref);
hlist_del_init_rcu(&zwplug->node);
spin_unlock_irqrestore(&disk->zone_wplugs_lock, flags);
}
static inline bool disk_should_remove_zone_wplug(struct gendisk *disk,
struct blk_zone_wplug *zwplug)
{
/* If the zone is still busy, the plug cannot be removed. */
if (zwplug->flags & BLK_ZONE_WPLUG_BUSY)
return false;
/* We can remove zone write plugs for zones that are empty or full. */
return !zwplug->wp_offset || zwplug->wp_offset >= disk->zone_capacity;
}
static struct blk_zone_wplug *disk_get_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 &&
atomic_inc_not_zero(&zwplug->ref)) {
rcu_read_unlock();
return zwplug;
}
}
rcu_read_unlock();
return NULL;
}
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 inline void disk_put_zone_wplug(struct blk_zone_wplug *zwplug)
{
if (atomic_dec_and_test(&zwplug->ref)) {
WARN_ON_ONCE(!bio_list_empty(&zwplug->bio_list));
WARN_ON_ONCE(!list_empty(&zwplug->link));
call_rcu(&zwplug->rcu_head, disk_free_zone_wplug_rcu);
}
}
static void blk_zone_wplug_bio_work(struct work_struct *work);
/*
* Get a reference on the write plug for the zone containing @sector.
* If the plug does not exist, it is allocated and hashed.
* Return a pointer to the zone write plug with the plug spinlock held.
*/
static struct blk_zone_wplug *disk_get_and_lock_zone_wplug(struct gendisk *disk,
sector_t sector, gfp_t gfp_mask,
unsigned long *flags)
{
unsigned int zno = disk_zone_no(disk, sector);
struct blk_zone_wplug *zwplug;
again:
zwplug = disk_get_zone_wplug(disk, sector);
if (zwplug) {
/*
* Check that a BIO completion or a zone reset or finish
* operation has not already removed the zone write plug from
* the hash table and dropped its reference count. In such case,
* we need to get a new plug so start over from the beginning.
*/
spin_lock_irqsave(&zwplug->lock, *flags);
if (zwplug->flags & BLK_ZONE_WPLUG_UNHASHED) {
spin_unlock_irqrestore(&zwplug->lock, *flags);
disk_put_zone_wplug(zwplug);
goto again;
}
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);
INIT_LIST_HEAD(&zwplug->link);
atomic_set(&zwplug->ref, 2);
spin_lock_init(&zwplug->lock);
zwplug->flags = 0;
zwplug->zone_no = zno;
zwplug->wp_offset = sector & (disk->queue->limits.chunk_sectors - 1);
bio_list_init(&zwplug->bio_list);
INIT_WORK(&zwplug->bio_work, blk_zone_wplug_bio_work);
zwplug->disk = disk;
spin_lock_irqsave(&zwplug->lock, *flags);
/*
* 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)) {
spin_unlock_irqrestore(&zwplug->lock, *flags);
mempool_free(zwplug, disk->zone_wplugs_pool);
goto again;
}
return zwplug;
}
static inline void blk_zone_wplug_bio_io_error(struct bio *bio)
{
struct request_queue *q = bio->bi_bdev->bd_disk->queue;
bio_clear_flag(bio, BIO_ZONE_WRITE_PLUGGING);
bio_io_error(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 bio *bio;
while ((bio = bio_list_pop(&zwplug->bio_list))) {
blk_zone_wplug_bio_io_error(bio);
disk_put_zone_wplug(zwplug);
}
}
/*
* Abort (fail) all plugged BIOs of a zone write plug that are not aligned
* with the assumed write pointer location of the zone when the BIO will
* be unplugged.
*/
static void disk_zone_wplug_abort_unaligned(struct gendisk *disk,
struct blk_zone_wplug *zwplug)
{
unsigned int zone_capacity = disk->zone_capacity;
unsigned int wp_offset = zwplug->wp_offset;
struct bio_list bl = BIO_EMPTY_LIST;
struct bio *bio;
while ((bio = bio_list_pop(&zwplug->bio_list))) {
if (wp_offset >= zone_capacity ||
(bio_op(bio) != REQ_OP_ZONE_APPEND &&
bio_offset_from_zone_start(bio) != wp_offset)) {
blk_zone_wplug_bio_io_error(bio);
disk_put_zone_wplug(zwplug);
continue;
}
wp_offset += bio_sectors(bio);
bio_list_add(&bl, bio);
}
bio_list_merge(&zwplug->bio_list, &bl);
}
/*
* Set a zone write plug write pointer offset to either 0 (zone reset case)
* or to the zone size (zone finish case). This aborts all plugged BIOs, which
* is fine to do as doing a zone reset or zone finish while writes are in-flight
* is a mistake from the user which will most likely cause all plugged BIOs to
* fail anyway.
*/
static void disk_zone_wplug_set_wp_offset(struct gendisk *disk,
struct blk_zone_wplug *zwplug,
unsigned int wp_offset)
{
unsigned long flags;
spin_lock_irqsave(&zwplug->lock, flags);
/*
* Make sure that a BIO completion or another zone reset or finish
* operation has not already removed the plug from the hash table.
*/
if (zwplug->flags & BLK_ZONE_WPLUG_UNHASHED) {
spin_unlock_irqrestore(&zwplug->lock, flags);
return;
}
/* Update the zone write pointer and abort all plugged BIOs. */
zwplug->wp_offset = wp_offset;
disk_zone_wplug_abort(zwplug);
/*
* Updating the write pointer offset puts back the zone
* in a good state. So clear the error flag and decrement the
* error count if we were in error state.
*/
if (zwplug->flags & BLK_ZONE_WPLUG_ERROR) {
zwplug->flags &= ~BLK_ZONE_WPLUG_ERROR;
spin_lock(&disk->zone_wplugs_lock);
list_del_init(&zwplug->link);
spin_unlock(&disk->zone_wplugs_lock);
}
/*
* The zone write plug now has no BIO plugged: remove it from the
* hash table so that it cannot be seen. The plug will be freed
* when the last reference is dropped.
*/
if (disk_should_remove_zone_wplug(disk, zwplug))
disk_remove_zone_wplug(disk, zwplug);
spin_unlock_irqrestore(&zwplug->lock, flags);
}
static bool blk_zone_wplug_handle_reset_or_finish(struct bio *bio,
unsigned int wp_offset)
{
struct gendisk *disk = bio->bi_bdev->bd_disk;
sector_t sector = bio->bi_iter.bi_sector;
struct blk_zone_wplug *zwplug;
/* Conventional zones cannot be reset nor finished. */
if (disk_zone_is_conv(disk, sector)) {
bio_io_error(bio);
return true;
}
/*
* If we have a zone write plug, set its write pointer offset to 0
* (reset case) or to the zone size (finish case). This will abort all
* BIOs plugged for the target zone. It is fine as resetting or
* finishing zones while writes are still in-flight will result in the
* writes failing anyway.
*/
zwplug = disk_get_zone_wplug(disk, sector);
if (zwplug) {
disk_zone_wplug_set_wp_offset(disk, zwplug, wp_offset);
disk_put_zone_wplug(zwplug);
}
return false;
}
static bool blk_zone_wplug_handle_reset_all(struct bio *bio)
{
struct gendisk *disk = bio->bi_bdev->bd_disk;
struct blk_zone_wplug *zwplug;
sector_t sector;
/*
* Set the write pointer offset of all zone write plugs to 0. This will
* abort all plugged BIOs. It is fine as resetting zones while writes
* are still in-flight will result in the writes failing anyway.
*/
for (sector = 0; sector < get_capacity(disk);
sector += disk->queue->limits.chunk_sectors) {
zwplug = disk_get_zone_wplug(disk, sector);
if (zwplug) {
disk_zone_wplug_set_wp_offset(disk, zwplug, 0);
disk_put_zone_wplug(zwplug);
}
}
return false;
}
static inline void blk_zone_wplug_add_bio(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);
}
/*
* 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 blk_zone_wplug *zwplug;
unsigned long flags;
/*
* If the BIO was already plugged, then we were called through
* blk_zone_write_plug_attempt_merge() -> blk_attempt_bio_merge().
* For this case, blk_zone_write_plug_attempt_merge() 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);
/*
* Increase the plug reference count and advance the zone write
* pointer offset.
*/
zwplug = disk_get_zone_wplug(bio->bi_bdev->bd_disk,
bio->bi_iter.bi_sector);
spin_lock_irqsave(&zwplug->lock, flags);
zwplug->wp_offset += bio_sectors(bio);
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_attempt_merge(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;
unsigned int zone_capacity = disk->zone_capacity;
struct blk_zone_wplug *zwplug =
disk_get_zone_wplug(disk, blk_rq_pos(req));
unsigned long flags;
struct bio *bio;
/*
* Completion of this request needs to be handled with
* blk_zone_write_plug_complete_request().
*/
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 (zwplug->wp_offset < zone_capacity) {
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 extra reference on the queue usage we got when
* plugging the BIO and advance the write pointer offset.
*/
blk_queue_exit(q);
zwplug->wp_offset += bio_sectors(bio);
req_back_sector += bio_sectors(bio);
}
spin_unlock_irqrestore(&zwplug->lock, flags);
}
static inline void disk_zone_wplug_set_error(struct gendisk *disk,
struct blk_zone_wplug *zwplug)
{
if (!(zwplug->flags & BLK_ZONE_WPLUG_ERROR)) {
unsigned long flags;
/*
* Increase the plug reference count. The reference will be
* dropped in disk_zone_wplugs_work() once the error state
* is handled.
*/
zwplug->flags |= BLK_ZONE_WPLUG_ERROR;
atomic_inc(&zwplug->ref);
spin_lock_irqsave(&disk->zone_wplugs_lock, flags);
list_add_tail(&zwplug->link, &disk->zone_wplugs_err_list);
spin_unlock_irqrestore(&disk->zone_wplugs_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;
/*
* 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 (zwplug->wp_offset >= disk->zone_capacity)
goto err;
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 because we avoid a
* whole lot of error handling trouble if we don't send it off
* to the driver.
*/
if (bio_offset_from_zone_start(bio) != zwplug->wp_offset)
goto err;
}
/* Advance the zone write pointer offset. */
zwplug->wp_offset += bio_sectors(bio);
return true;
err:
/* We detected an invalid write BIO: schedule error recovery. */
disk_zone_wplug_set_error(disk, zwplug);
kblockd_schedule_work(&disk->zone_wplugs_work);
return false;
}
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 (disk_zone_is_conv(disk, 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_and_lock_zone_wplug(disk, sector, gfp_mask, &flags);
if (!zwplug) {
bio_io_error(bio);
return true;