linux/drivers/md/dm-zone.c
Mike Snitzer 564b5c5476 dm table: audit all dm_table_get_target() callers
All callers of dm_table_get_target() are expected to do proper bounds
checking on the index they pass.

Move dm_table_get_target() to dm-core.h to make it extra clear that only
DM core code should be using it. Switch it to be inlined while at it.

Standardize all DM core callers to use the same for loop pattern and
make associated variables as local as possible. Rename some variables
(e.g. s/table/t/ and s/tgt/ti/) along the way.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2022-07-07 11:49:34 -04:00

651 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2021 Western Digital Corporation or its affiliates.
*/
#include <linux/blkdev.h>
#include <linux/mm.h>
#include <linux/sched/mm.h>
#include <linux/slab.h>
#include "dm-core.h"
#define DM_MSG_PREFIX "zone"
#define DM_ZONE_INVALID_WP_OFST UINT_MAX
/*
* For internal zone reports bypassing the top BIO submission path.
*/
static int dm_blk_do_report_zones(struct mapped_device *md, struct dm_table *t,
sector_t sector, unsigned int nr_zones,
report_zones_cb cb, void *data)
{
struct gendisk *disk = md->disk;
int ret;
struct dm_report_zones_args args = {
.next_sector = sector,
.orig_data = data,
.orig_cb = cb,
};
do {
struct dm_target *tgt;
tgt = dm_table_find_target(t, args.next_sector);
if (WARN_ON_ONCE(!tgt->type->report_zones))
return -EIO;
args.tgt = tgt;
ret = tgt->type->report_zones(tgt, &args,
nr_zones - args.zone_idx);
if (ret < 0)
return ret;
} while (args.zone_idx < nr_zones &&
args.next_sector < get_capacity(disk));
return args.zone_idx;
}
/*
* User facing dm device block device report zone operation. This calls the
* report_zones operation for each target of a device table. This operation is
* generally implemented by targets using dm_report_zones().
*/
int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
unsigned int nr_zones, report_zones_cb cb, void *data)
{
struct mapped_device *md = disk->private_data;
struct dm_table *map;
int srcu_idx, ret;
if (dm_suspended_md(md))
return -EAGAIN;
map = dm_get_live_table(md, &srcu_idx);
if (!map)
return -EIO;
ret = dm_blk_do_report_zones(md, map, sector, nr_zones, cb, data);
dm_put_live_table(md, srcu_idx);
return ret;
}
static int dm_report_zones_cb(struct blk_zone *zone, unsigned int idx,
void *data)
{
struct dm_report_zones_args *args = data;
sector_t sector_diff = args->tgt->begin - args->start;
/*
* Ignore zones beyond the target range.
*/
if (zone->start >= args->start + args->tgt->len)
return 0;
/*
* Remap the start sector and write pointer position of the zone
* to match its position in the target range.
*/
zone->start += sector_diff;
if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) {
if (zone->cond == BLK_ZONE_COND_FULL)
zone->wp = zone->start + zone->len;
else if (zone->cond == BLK_ZONE_COND_EMPTY)
zone->wp = zone->start;
else
zone->wp += sector_diff;
}
args->next_sector = zone->start + zone->len;
return args->orig_cb(zone, args->zone_idx++, args->orig_data);
}
/*
* Helper for drivers of zoned targets to implement struct target_type
* report_zones operation.
*/
int dm_report_zones(struct block_device *bdev, sector_t start, sector_t sector,
struct dm_report_zones_args *args, unsigned int nr_zones)
{
/*
* Set the target mapping start sector first so that
* dm_report_zones_cb() can correctly remap zone information.
*/
args->start = start;
return blkdev_report_zones(bdev, sector, nr_zones,
dm_report_zones_cb, args);
}
EXPORT_SYMBOL_GPL(dm_report_zones);
bool dm_is_zone_write(struct mapped_device *md, struct bio *bio)
{
struct request_queue *q = md->queue;
if (!blk_queue_is_zoned(q))
return false;
switch (bio_op(bio)) {
case REQ_OP_WRITE_ZEROES:
case REQ_OP_WRITE:
return !op_is_flush(bio->bi_opf) && bio_sectors(bio);
default:
return false;
}
}
void dm_cleanup_zoned_dev(struct mapped_device *md)
{
struct request_queue *q = md->queue;
if (q) {
kfree(q->conv_zones_bitmap);
q->conv_zones_bitmap = NULL;
kfree(q->seq_zones_wlock);
q->seq_zones_wlock = NULL;
}
kvfree(md->zwp_offset);
md->zwp_offset = NULL;
md->nr_zones = 0;
}
static unsigned int dm_get_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:
return zone->wp - zone->start;
case BLK_ZONE_COND_FULL:
return zone->len;
case BLK_ZONE_COND_EMPTY:
case BLK_ZONE_COND_NOT_WP:
case BLK_ZONE_COND_OFFLINE:
case BLK_ZONE_COND_READONLY:
default:
/*
* Conventional, offline and read-only zones do not have a valid
* write pointer. Use 0 as for an empty zone.
*/
return 0;
}
}
static int dm_zone_revalidate_cb(struct blk_zone *zone, unsigned int idx,
void *data)
{
struct mapped_device *md = data;
struct request_queue *q = md->queue;
switch (zone->type) {
case BLK_ZONE_TYPE_CONVENTIONAL:
if (!q->conv_zones_bitmap) {
q->conv_zones_bitmap =
kcalloc(BITS_TO_LONGS(q->nr_zones),
sizeof(unsigned long), GFP_NOIO);
if (!q->conv_zones_bitmap)
return -ENOMEM;
}
set_bit(idx, q->conv_zones_bitmap);
break;
case BLK_ZONE_TYPE_SEQWRITE_REQ:
case BLK_ZONE_TYPE_SEQWRITE_PREF:
if (!q->seq_zones_wlock) {
q->seq_zones_wlock =
kcalloc(BITS_TO_LONGS(q->nr_zones),
sizeof(unsigned long), GFP_NOIO);
if (!q->seq_zones_wlock)
return -ENOMEM;
}
if (!md->zwp_offset) {
md->zwp_offset =
kvcalloc(q->nr_zones, sizeof(unsigned int),
GFP_KERNEL);
if (!md->zwp_offset)
return -ENOMEM;
}
md->zwp_offset[idx] = dm_get_zone_wp_offset(zone);
break;
default:
DMERR("Invalid zone type 0x%x at sectors %llu",
(int)zone->type, zone->start);
return -ENODEV;
}
return 0;
}
/*
* Revalidate the zones of a mapped device to initialize resource necessary
* for zone append emulation. Note that we cannot simply use the block layer
* blk_revalidate_disk_zones() function here as the mapped device is suspended
* (this is called from __bind() context).
*/
static int dm_revalidate_zones(struct mapped_device *md, struct dm_table *t)
{
struct request_queue *q = md->queue;
unsigned int noio_flag;
int ret;
/*
* Check if something changed. If yes, cleanup the current resources
* and reallocate everything.
*/
if (!q->nr_zones || q->nr_zones != md->nr_zones)
dm_cleanup_zoned_dev(md);
if (md->nr_zones)
return 0;
/*
* Scan all zones to initialize everything. Ensure that all vmalloc
* operations in this context are done as if GFP_NOIO was specified.
*/
noio_flag = memalloc_noio_save();
ret = dm_blk_do_report_zones(md, t, 0, q->nr_zones,
dm_zone_revalidate_cb, md);
memalloc_noio_restore(noio_flag);
if (ret < 0)
goto err;
if (ret != q->nr_zones) {
ret = -EIO;
goto err;
}
md->nr_zones = q->nr_zones;
return 0;
err:
DMERR("Revalidate zones failed %d", ret);
dm_cleanup_zoned_dev(md);
return ret;
}
static int device_not_zone_append_capable(struct dm_target *ti,
struct dm_dev *dev, sector_t start,
sector_t len, void *data)
{
return !blk_queue_is_zoned(bdev_get_queue(dev->bdev));
}
static bool dm_table_supports_zone_append(struct dm_table *t)
{
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (ti->emulate_zone_append)
return false;
if (!ti->type->iterate_devices ||
ti->type->iterate_devices(ti, device_not_zone_append_capable, NULL))
return false;
}
return true;
}
int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q)
{
struct mapped_device *md = t->md;
/*
* For a zoned target, the number of zones should be updated for the
* correct value to be exposed in sysfs queue/nr_zones.
*/
WARN_ON_ONCE(queue_is_mq(q));
q->nr_zones = blkdev_nr_zones(md->disk);
/* Check if zone append is natively supported */
if (dm_table_supports_zone_append(t)) {
clear_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
dm_cleanup_zoned_dev(md);
return 0;
}
/*
* Mark the mapped device as needing zone append emulation and
* initialize the emulation resources once the capacity is set.
*/
set_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
if (!get_capacity(md->disk))
return 0;
return dm_revalidate_zones(md, t);
}
static int dm_update_zone_wp_offset_cb(struct blk_zone *zone, unsigned int idx,
void *data)
{
unsigned int *wp_offset = data;
*wp_offset = dm_get_zone_wp_offset(zone);
return 0;
}
static int dm_update_zone_wp_offset(struct mapped_device *md, unsigned int zno,
unsigned int *wp_ofst)
{
sector_t sector = zno * blk_queue_zone_sectors(md->queue);
unsigned int noio_flag;
struct dm_table *t;
int srcu_idx, ret;
t = dm_get_live_table(md, &srcu_idx);
if (!t)
return -EIO;
/*
* Ensure that all memory allocations in this context are done as if
* GFP_NOIO was specified.
*/
noio_flag = memalloc_noio_save();
ret = dm_blk_do_report_zones(md, t, sector, 1,
dm_update_zone_wp_offset_cb, wp_ofst);
memalloc_noio_restore(noio_flag);
dm_put_live_table(md, srcu_idx);
if (ret != 1)
return -EIO;
return 0;
}
struct orig_bio_details {
unsigned int op;
unsigned int nr_sectors;
};
/*
* First phase of BIO mapping for targets with zone append emulation:
* check all BIO that change a zone writer pointer and change zone
* append operations into regular write operations.
*/
static bool dm_zone_map_bio_begin(struct mapped_device *md,
unsigned int zno, struct bio *clone)
{
sector_t zsectors = blk_queue_zone_sectors(md->queue);
unsigned int zwp_offset = READ_ONCE(md->zwp_offset[zno]);
/*
* If the target zone is in an error state, recover by inspecting the
* zone to get its current write pointer position. Note that since the
* target zone is already locked, a BIO issuing context should never
* see the zone write in the DM_ZONE_UPDATING_WP_OFST state.
*/
if (zwp_offset == DM_ZONE_INVALID_WP_OFST) {
if (dm_update_zone_wp_offset(md, zno, &zwp_offset))
return false;
WRITE_ONCE(md->zwp_offset[zno], zwp_offset);
}
switch (bio_op(clone)) {
case REQ_OP_ZONE_RESET:
case REQ_OP_ZONE_FINISH:
return true;
case REQ_OP_WRITE_ZEROES:
case REQ_OP_WRITE:
/* Writes must be aligned to the zone write pointer */
if ((clone->bi_iter.bi_sector & (zsectors - 1)) != zwp_offset)
return false;
break;
case REQ_OP_ZONE_APPEND:
/*
* Change zone append operations into a non-mergeable regular
* writes directed at the current write pointer position of the
* target zone.
*/
clone->bi_opf = REQ_OP_WRITE | REQ_NOMERGE |
(clone->bi_opf & (~REQ_OP_MASK));
clone->bi_iter.bi_sector += zwp_offset;
break;
default:
DMWARN_LIMIT("Invalid BIO operation");
return false;
}
/* Cannot write to a full zone */
if (zwp_offset >= zsectors)
return false;
return true;
}
/*
* Second phase of BIO mapping for targets with zone append emulation:
* update the zone write pointer offset array to account for the additional
* data written to a zone. Note that at this point, the remapped clone BIO
* may already have completed, so we do not touch it.
*/
static blk_status_t dm_zone_map_bio_end(struct mapped_device *md, unsigned int zno,
struct orig_bio_details *orig_bio_details,
unsigned int nr_sectors)
{
unsigned int zwp_offset = READ_ONCE(md->zwp_offset[zno]);
/* The clone BIO may already have been completed and failed */
if (zwp_offset == DM_ZONE_INVALID_WP_OFST)
return BLK_STS_IOERR;
/* Update the zone wp offset */
switch (orig_bio_details->op) {
case REQ_OP_ZONE_RESET:
WRITE_ONCE(md->zwp_offset[zno], 0);
return BLK_STS_OK;
case REQ_OP_ZONE_FINISH:
WRITE_ONCE(md->zwp_offset[zno],
blk_queue_zone_sectors(md->queue));
return BLK_STS_OK;
case REQ_OP_WRITE_ZEROES:
case REQ_OP_WRITE:
WRITE_ONCE(md->zwp_offset[zno], zwp_offset + nr_sectors);
return BLK_STS_OK;
case REQ_OP_ZONE_APPEND:
/*
* Check that the target did not truncate the write operation
* emulating a zone append.
*/
if (nr_sectors != orig_bio_details->nr_sectors) {
DMWARN_LIMIT("Truncated write for zone append");
return BLK_STS_IOERR;
}
WRITE_ONCE(md->zwp_offset[zno], zwp_offset + nr_sectors);
return BLK_STS_OK;
default:
DMWARN_LIMIT("Invalid BIO operation");
return BLK_STS_IOERR;
}
}
static inline void dm_zone_lock(struct request_queue *q,
unsigned int zno, struct bio *clone)
{
if (WARN_ON_ONCE(bio_flagged(clone, BIO_ZONE_WRITE_LOCKED)))
return;
wait_on_bit_lock_io(q->seq_zones_wlock, zno, TASK_UNINTERRUPTIBLE);
bio_set_flag(clone, BIO_ZONE_WRITE_LOCKED);
}
static inline void dm_zone_unlock(struct request_queue *q,
unsigned int zno, struct bio *clone)
{
if (!bio_flagged(clone, BIO_ZONE_WRITE_LOCKED))
return;
WARN_ON_ONCE(!test_bit(zno, q->seq_zones_wlock));
clear_bit_unlock(zno, q->seq_zones_wlock);
smp_mb__after_atomic();
wake_up_bit(q->seq_zones_wlock, zno);
bio_clear_flag(clone, BIO_ZONE_WRITE_LOCKED);
}
static bool dm_need_zone_wp_tracking(struct bio *bio)
{
/*
* Special processing is not needed for operations that do not need the
* zone write lock, that is, all operations that target conventional
* zones and all operations that do not modify directly a sequential
* zone write pointer.
*/
if (op_is_flush(bio->bi_opf) && !bio_sectors(bio))
return false;
switch (bio_op(bio)) {
case REQ_OP_WRITE_ZEROES:
case REQ_OP_WRITE:
case REQ_OP_ZONE_RESET:
case REQ_OP_ZONE_FINISH:
case REQ_OP_ZONE_APPEND:
return bio_zone_is_seq(bio);
default:
return false;
}
}
/*
* Special IO mapping for targets needing zone append emulation.
*/
int dm_zone_map_bio(struct dm_target_io *tio)
{
struct dm_io *io = tio->io;
struct dm_target *ti = tio->ti;
struct mapped_device *md = io->md;
struct request_queue *q = md->queue;
struct bio *clone = &tio->clone;
struct orig_bio_details orig_bio_details;
unsigned int zno;
blk_status_t sts;
int r;
/*
* IOs that do not change a zone write pointer do not need
* any additional special processing.
*/
if (!dm_need_zone_wp_tracking(clone))
return ti->type->map(ti, clone);
/* Lock the target zone */
zno = bio_zone_no(clone);
dm_zone_lock(q, zno, clone);
orig_bio_details.nr_sectors = bio_sectors(clone);
orig_bio_details.op = bio_op(clone);
/*
* Check that the bio and the target zone write pointer offset are
* both valid, and if the bio is a zone append, remap it to a write.
*/
if (!dm_zone_map_bio_begin(md, zno, clone)) {
dm_zone_unlock(q, zno, clone);
return DM_MAPIO_KILL;
}
/* Let the target do its work */
r = ti->type->map(ti, clone);
switch (r) {
case DM_MAPIO_SUBMITTED:
/*
* The target submitted the clone BIO. The target zone will
* be unlocked on completion of the clone.
*/
sts = dm_zone_map_bio_end(md, zno, &orig_bio_details,
*tio->len_ptr);
break;
case DM_MAPIO_REMAPPED:
/*
* The target only remapped the clone BIO. In case of error,
* unlock the target zone here as the clone will not be
* submitted.
*/
sts = dm_zone_map_bio_end(md, zno, &orig_bio_details,
*tio->len_ptr);
if (sts != BLK_STS_OK)
dm_zone_unlock(q, zno, clone);
break;
case DM_MAPIO_REQUEUE:
case DM_MAPIO_KILL:
default:
dm_zone_unlock(q, zno, clone);
sts = BLK_STS_IOERR;
break;
}
if (sts != BLK_STS_OK)
return DM_MAPIO_KILL;
return r;
}
/*
* IO completion callback called from clone_endio().
*/
void dm_zone_endio(struct dm_io *io, struct bio *clone)
{
struct mapped_device *md = io->md;
struct request_queue *q = md->queue;
struct bio *orig_bio = io->orig_bio;
unsigned int zwp_offset;
unsigned int zno;
/*
* For targets that do not emulate zone append, we only need to
* handle native zone-append bios.
*/
if (!dm_emulate_zone_append(md)) {
/*
* Get the offset within the zone of the written sector
* and add that to the original bio sector position.
*/
if (clone->bi_status == BLK_STS_OK &&
bio_op(clone) == REQ_OP_ZONE_APPEND) {
sector_t mask = (sector_t)blk_queue_zone_sectors(q) - 1;
orig_bio->bi_iter.bi_sector +=
clone->bi_iter.bi_sector & mask;
}
return;
}
/*
* For targets that do emulate zone append, if the clone BIO does not
* own the target zone write lock, we have nothing to do.
*/
if (!bio_flagged(clone, BIO_ZONE_WRITE_LOCKED))
return;
zno = bio_zone_no(orig_bio);
if (clone->bi_status != BLK_STS_OK) {
/*
* BIOs that modify a zone write pointer may leave the zone
* in an unknown state in case of failure (e.g. the write
* pointer was only partially advanced). In this case, set
* the target zone write pointer as invalid unless it is
* already being updated.
*/
WRITE_ONCE(md->zwp_offset[zno], DM_ZONE_INVALID_WP_OFST);
} else if (bio_op(orig_bio) == REQ_OP_ZONE_APPEND) {
/*
* Get the written sector for zone append operation that were
* emulated using regular write operations.
*/
zwp_offset = READ_ONCE(md->zwp_offset[zno]);
if (WARN_ON_ONCE(zwp_offset < bio_sectors(orig_bio)))
WRITE_ONCE(md->zwp_offset[zno],
DM_ZONE_INVALID_WP_OFST);
else
orig_bio->bi_iter.bi_sector +=
zwp_offset - bio_sectors(orig_bio);
}
dm_zone_unlock(q, zno, clone);
}