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block: allocate struct hd_struct as part of struct bdev_inode

Browse Source 
Allocate hd_struct together with struct block_device to pre-load
the lifetime rule changes in preparation of merging the two structures.

Note that part0 was previously embedded into struct gendisk, but is
a separate allocation now, and already points to the block_device instead
of the hd_struct.  The lifetime of struct gendisk is still controlled by
the struct device embedded in the part0 hd_struct.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2020-11-26 18:47:17 +01:00 committed by Jens Axboe
parent 83950d3590
commit cb8432d650
15 changed files with 61 additions and 169 deletions
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16
block/blk-core.c
View File

@ -714,7 +714,8 @@ static inline bool bio_check_ro(struct bio *bio, struct hd_struct *part)
static noinline int should_fail_bio(struct bio *bio)
{
if (should_fail_request(&bio->bi_disk->part0, bio->bi_iter.bi_size))
if (should_fail_request(bio->bi_disk->part0->bd_part,
bio->bi_iter.bi_size))
return -EIO;
return 0;
}
@ -831,7 +832,7 @@ static noinline_for_stack bool submit_bio_checks(struct bio *bio)
if (unlikely(blk_partition_remap(bio)))
goto end_io;
} else {
if (unlikely(bio_check_ro(bio, &bio->bi_disk->part0)))
if (unlikely(bio_check_ro(bio, bio->bi_disk->part0->bd_part)))
goto end_io;
if (unlikely(bio_check_eod(bio, get_capacity(bio->bi_disk))))
goto end_io;
@ -1203,7 +1204,7 @@ blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *
return ret;
if (rq->rq_disk &&
should_fail_request(&rq->rq_disk->part0, blk_rq_bytes(rq)))
should_fail_request(rq->rq_disk->part0->bd_part, blk_rq_bytes(rq)))
return BLK_STS_IOERR;
if (blk_crypto_insert_cloned_request(rq))
@ -1272,7 +1273,7 @@ again:
__part_stat_add(part, io_ticks, end ? now - stamp : 1);
}
if (part->partno) {
part = &part_to_disk(part)->part0;
part = part_to_disk(part)->part0->bd_part;
goto again;
}
}
@ -1309,8 +1310,6 @@ void blk_account_io_done(struct request *req, u64 now)
part_stat_inc(part, ios[sgrp]);
part_stat_add(part, nsecs[sgrp], now - req->start_time_ns);
part_stat_unlock();
hd_struct_put(part);
}
}
@ -1354,7 +1353,7 @@ EXPORT_SYMBOL_GPL(part_start_io_acct);
unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors,
unsigned int op)
{
return __part_start_io_acct(&disk->part0, sectors, op);
return __part_start_io_acct(disk->part0->bd_part, sectors, op);
}
EXPORT_SYMBOL(disk_start_io_acct);
@ -1376,14 +1375,13 @@ void part_end_io_acct(struct hd_struct *part, struct bio *bio,
unsigned long start_time)
{
__part_end_io_acct(part, bio_op(bio), start_time);
hd_struct_put(part);
}
EXPORT_SYMBOL_GPL(part_end_io_acct);
void disk_end_io_acct(struct gendisk *disk, unsigned int op,
unsigned long start_time)
{
__part_end_io_acct(&disk->part0, op, start_time);
__part_end_io_acct(disk->part0->bd_part, op, start_time);
}
EXPORT_SYMBOL(disk_end_io_acct);

2
block/blk-flush.c
View File

@ -139,7 +139,7 @@ static void blk_flush_queue_rq(struct request *rq, bool add_front)
static void blk_account_io_flush(struct request *rq)
{
struct hd_struct *part = &rq->rq_disk->part0;
struct hd_struct *part = rq->rq_disk->part0->bd_part;
part_stat_lock();
part_stat_inc(part, ios[STAT_FLUSH]);

2
block/blk-merge.c
View File

@ -683,8 +683,6 @@ static void blk_account_io_merge_request(struct request *req)
part_stat_lock();
part_stat_inc(req->part, merges[op_stat_group(req_op(req))]);
part_stat_unlock();
hd_struct_put(req->part);
}
}

21
block/blk.h
View File

@ -363,27 +363,6 @@ int bdev_del_partition(struct block_device *bdev, int partno);
int bdev_resize_partition(struct block_device *bdev, int partno,
sector_t start, sector_t length);
int disk_expand_part_tbl(struct gendisk *disk, int target);
int hd_ref_init(struct hd_struct *part);
/* no need to get/put refcount of part0 */
static inline int hd_struct_try_get(struct hd_struct *part)
{
if (part->partno)
return percpu_ref_tryget_live(&part->ref);
return 1;
}
static inline void hd_struct_put(struct hd_struct *part)
{
if (part->partno)
percpu_ref_put(&part->ref);
}
static inline void hd_free_part(struct hd_struct *part)
{
bdput(part->bdev);
percpu_ref_exit(&part->ref);
}
int bio_add_hw_page(struct request_queue *q, struct bio *bio,
struct page *page, unsigned int len, unsigned int offset,

50
block/genhd.c
View File

@ -42,7 +42,7 @@ static void disk_release_events(struct gendisk *disk);
void set_capacity(struct gendisk *disk, sector_t sectors)
{
struct block_device *bdev = disk->part0.bdev;
struct block_device *bdev = disk->part0;
spin_lock(&bdev->bd_size_lock);
i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
@ -318,9 +318,7 @@ static inline int sector_in_part(struct hd_struct *part, sector_t sector)
* primarily used for stats accounting.
*
* CONTEXT:
* RCU read locked. The returned partition pointer is always valid
* because its refcount is grabbed except for part0, which lifetime
* is same with the disk.
* RCU read locked.
*
* RETURNS:
* Found partition on success, part0 is returned if no partition matches
@ -336,26 +334,19 @@ struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
ptbl = rcu_dereference(disk->part_tbl);
part = rcu_dereference(ptbl->last_lookup);
if (part && sector_in_part(part, sector) && hd_struct_try_get(part))
if (part && sector_in_part(part, sector))
goto out_unlock;
for (i = 1; i < ptbl->len; i++) {
part = rcu_dereference(ptbl->part[i]);
if (part && sector_in_part(part, sector)) {
/*
* only live partition can be cached for lookup,
* so use-after-free on cached & deleting partition
* can be avoided
*/
if (!hd_struct_try_get(part))
break;
rcu_assign_pointer(ptbl->last_lookup, part);
goto out_unlock;
}
}
part = &disk->part0;
part = disk->part0->bd_part;
out_unlock:
rcu_read_unlock();
return part;
@ -681,8 +672,8 @@ static void register_disk(struct device *parent, struct gendisk *disk,
*/
pm_runtime_set_memalloc_noio(ddev, true);
disk->part0.bdev->bd_holder_dir =
kobject_create_and_add("holders", &ddev->kobj);
disk->part0->bd_holder_dir =
kobject_create_and_add("holders", &ddev->kobj);
disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
if (disk->flags & GENHD_FL_HIDDEN) {
@ -748,7 +739,7 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk,
disk->flags |= GENHD_FL_UP;
retval = blk_alloc_devt(&disk->part0, &devt);
retval = blk_alloc_devt(disk->part0->bd_part, &devt);
if (retval) {
WARN_ON(1);
return;
@ -775,7 +766,7 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk,
ret = bdi_register(bdi, "%u:%u", MAJOR(devt), MINOR(devt));
WARN_ON(ret);
bdi_set_owner(bdi, dev);
bdev_add(disk->part0.bdev, devt);
bdev_add(disk->part0, devt);
}
register_disk(parent, disk, groups);
if (register_queue)
@ -888,11 +879,11 @@ void del_gendisk(struct gendisk *disk)
blk_unregister_queue(disk);
kobject_put(disk->part0.bdev->bd_holder_dir);
kobject_put(disk->part0->bd_holder_dir);
kobject_put(disk->slave_dir);
part_stat_set_all(&disk->part0, 0);
disk->part0.bdev->bd_stamp = 0;
part_stat_set_all(disk->part0->bd_part, 0);
disk->part0->bd_stamp = 0;
if (!sysfs_deprecated)
sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
@ -1005,7 +996,7 @@ void __init printk_all_partitions(void)
*/
disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
while ((part = disk_part_iter_next(&piter))) {
bool is_part0 = part == &disk->part0;
bool is_part0 = part == disk->part0->bd_part;
printk("%s%s %10llu %s %s", is_part0 ? "" : " ",
bdevt_str(part_devt(part), devt_buf),
@ -1460,7 +1451,7 @@ static void disk_release(struct device *dev)
disk_release_events(disk);
kfree(disk->random);
disk_replace_part_tbl(disk, NULL);
hd_free_part(&disk->part0);
bdput(disk->part0);
if (disk->queue)
blk_put_queue(disk->queue);
kfree(disk);
@ -1626,8 +1617,8 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
if (!disk)
return NULL;
disk->part0.bdev = bdev_alloc(disk, 0);
if (!disk->part0.bdev)
disk->part0 = bdev_alloc(disk, 0);
if (!disk->part0)
goto out_free_disk;
disk->node_id = node_id;
@ -1635,10 +1626,7 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
goto out_bdput;
ptbl = rcu_dereference_protected(disk->part_tbl, 1);
rcu_assign_pointer(ptbl->part[0], &disk->part0);
if (hd_ref_init(&disk->part0))
goto out_bdput;
rcu_assign_pointer(ptbl->part[0], disk->part0->bd_part);
disk->minors = minors;
rand_initialize_disk(disk);
@ -1648,7 +1636,7 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
return disk;
out_bdput:
bdput(disk->part0.bdev);
bdput(disk->part0);
out_free_disk:
kfree(disk);
return NULL;
@ -1687,9 +1675,9 @@ void set_disk_ro(struct gendisk *disk, int flag)
struct disk_part_iter piter;
struct hd_struct *part;
if (disk->part0.bdev->bd_read_only != flag) {
if (disk->part0->bd_read_only != flag) {
set_disk_ro_uevent(disk, flag);
disk->part0.bdev->bd_read_only = flag;
disk->part0->bd_read_only = flag;
}
disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);

67
block/partitions/core.c
View File

@ -265,9 +265,9 @@ static const struct attribute_group *part_attr_groups[] = {
static void part_release(struct device *dev)
{
struct hd_struct *p = dev_to_part(dev);
blk_free_devt(dev->devt);
hd_free_part(p);
kfree(p);
bdput(p->bdev);
}
static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
@ -288,46 +288,6 @@ struct device_type part_type = {
.uevent = part_uevent,
};
static void hd_struct_free_work(struct work_struct *work)
{
struct hd_struct *part =
container_of(to_rcu_work(work), struct hd_struct, rcu_work);
struct gendisk *disk = part_to_disk(part);
/*
* Release the disk reference acquired in delete_partition here.
* We can't release it in hd_struct_free because the final put_device
* needs process context and thus can't be run directly from a
* percpu_ref ->release handler.
*/
put_device(disk_to_dev(disk));
part->bdev->bd_start_sect = 0;
bdev_set_nr_sectors(part->bdev, 0);
part_stat_set_all(part, 0);
put_device(part_to_dev(part));
}
static void hd_struct_free(struct percpu_ref *ref)
{
struct hd_struct *part = container_of(ref, struct hd_struct, ref);
struct gendisk *disk = part_to_disk(part);
struct disk_part_tbl *ptbl =
rcu_dereference_protected(disk->part_tbl, 1);
rcu_assign_pointer(ptbl->last_lookup, NULL);
INIT_RCU_WORK(&part->rcu_work, hd_struct_free_work);
queue_rcu_work(system_wq, &part->rcu_work);
}
int hd_ref_init(struct hd_struct *part)
{
if (percpu_ref_init(&part->ref, hd_struct_free, 0, GFP_KERNEL))
return -ENOMEM;
return 0;
}
/*
* Must be called either with bd_mutex held, before a disk can be opened or
* after all disk users are gone.
@ -342,8 +302,8 @@ void delete_partition(struct hd_struct *part)
* ->part_tbl is referenced in this part's release handler, so
* we have to hold the disk device
*/
get_device(disk_to_dev(disk));
rcu_assign_pointer(ptbl->part[part->partno], NULL);
rcu_assign_pointer(ptbl->last_lookup, NULL);
kobject_put(part->bdev->bd_holder_dir);
device_del(part_to_dev(part));
@ -353,7 +313,7 @@ void delete_partition(struct hd_struct *part)
*/
remove_inode_hash(part->bdev->bd_inode);
percpu_ref_kill(&part->ref);
put_device(part_to_dev(part));
}
static ssize_t whole_disk_show(struct device *dev,
@ -406,15 +366,11 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno,
if (ptbl->part[partno])
return ERR_PTR(-EBUSY);
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return ERR_PTR(-EBUSY);
bdev = bdev_alloc(disk, partno);
if (!bdev)
goto out_free;
p->bdev = bdev;
return ERR_PTR(-ENOMEM);
p = bdev->bd_part;
pdev = part_to_dev(p);
bdev->bd_start_sect = start;
@ -463,13 +419,6 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno,
goto out_del;
}
err = hd_ref_init(p);
if (err) {
if (flags & ADDPART_FLAG_WHOLEDISK)
goto out_remove_file;
goto out_del;
}
/* everything is up and running, commence */
bdev_add(bdev, devt);
rcu_assign_pointer(ptbl->part[partno], p);
@ -481,11 +430,7 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno,
out_bdput:
bdput(bdev);
out_free:
kfree(p);
return ERR_PTR(err);
out_remove_file:
device_remove_file(pdev, &dev_attr_whole_disk);
out_del:
kobject_put(bdev->bd_holder_dir);
device_del(pdev);

2
drivers/block/drbd/drbd_receiver.c
View File

@ -2802,7 +2802,7 @@ bool drbd_rs_c_min_rate_throttle(struct drbd_device *device)
if (c_min_rate == 0)
return false;
curr_events = (int)part_stat_read_accum(&disk->part0, sectors) -
curr_events = (int)part_stat_read_accum(disk->part0->bd_part, sectors) -
atomic_read(&device->rs_sect_ev);
if (atomic_read(&device->ap_actlog_cnt)

3
drivers/block/drbd/drbd_worker.c
View File

@ -1678,7 +1678,8 @@ void drbd_rs_controller_reset(struct drbd_device *device)
atomic_set(&device->rs_sect_in, 0);
atomic_set(&device->rs_sect_ev, 0);
device->rs_in_flight = 0;
device->rs_last_events = (int)part_stat_read_accum(&disk->part0, sectors);
device->rs_last_events =
(int)part_stat_read_accum(disk->part0->bd_part, sectors);
/* Updating the RCU protected object in place is necessary since
this function gets called from atomic context.

2
drivers/block/zram/zram_drv.c
View File

@ -1687,7 +1687,7 @@ static void zram_reset_device(struct zram *zram)
zram->disksize = 0;
set_capacity_and_notify(zram->disk, 0);
part_stat_set_all(&zram->disk->part0, 0);
part_stat_set_all(zram->disk->part0->bd_part, 0);
up_write(&zram->init_lock);
/* I/O operation under all of CPU are done so let's free */

4
drivers/md/dm.c
View File

@ -1607,7 +1607,7 @@ static blk_qc_t __split_and_process_bio(struct mapped_device *md,
* (by eliminating DM's splitting and just using bio_split)
*/
part_stat_lock();
__dm_part_stat_sub(&dm_disk(md)->part0,
__dm_part_stat_sub(dm_disk(md)->part0->bd_part,
sectors[op_stat_group(bio_op(bio))], ci.sector_count);
part_stat_unlock();
@ -2242,7 +2242,7 @@ EXPORT_SYMBOL_GPL(dm_put);
static bool md_in_flight_bios(struct mapped_device *md)
{
int cpu;
struct hd_struct *part = &dm_disk(md)->part0;
struct hd_struct *part = dm_disk(md)->part0->bd_part;
long sum = 0;
for_each_possible_cpu(cpu) {

2
drivers/md/md.c
View File

@ -8441,7 +8441,7 @@ static int is_mddev_idle(struct mddev *mddev, int init)
rcu_read_lock();
rdev_for_each_rcu(rdev, mddev) {
struct gendisk *disk = rdev->bdev->bd_disk;
curr_events = (int)part_stat_read_accum(&disk->part0, sectors) -
curr_events = (int)part_stat_read_accum(disk->part0->bd_part, sectors) -
atomic_read(&disk->sync_io);
/* sync IO will cause sync_io to increase before the disk_stats
* as sync_io is counted when a request starts, and

39
fs/block_dev.c
View File

@ -39,6 +39,7 @@
struct bdev_inode {
struct block_device bdev;
struct hd_struct hd;
struct inode vfs_inode;
};
@ -886,6 +887,9 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno)
iput(inode);
return NULL;
}
bdev->bd_part = &BDEV_I(inode)->hd;
memset(bdev->bd_part, 0, sizeof(*bdev->bd_part));
bdev->bd_part->bdev = bdev;
return bdev;
}
@ -1280,15 +1284,10 @@ EXPORT_SYMBOL_GPL(bdev_disk_changed);
static int __blkdev_get(struct block_device *bdev, fmode_t mode)
{
struct gendisk *disk = bdev->bd_disk;
int ret;
int ret = 0;
if (!bdev->bd_openers) {
if (!bdev_is_partition(bdev)) {
ret = -ENXIO;
bdev->bd_part = disk_get_part(disk, 0);
if (!bdev->bd_part)
goto out_clear;
ret = 0;
if (disk->fops->open)
ret = disk->fops->open(bdev, mode);
@ -1307,7 +1306,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode)
bdev_disk_changed(bdev, ret == -ENOMEDIUM);
if (ret)
goto out_clear;
return ret;
} else {
struct block_device *whole = bdget_disk(disk, 0);
@ -1316,18 +1315,16 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode)
if (ret) {
mutex_unlock(&whole->bd_mutex);
bdput(whole);
goto out_clear;
return ret;
}
whole->bd_part_count++;
mutex_unlock(&whole->bd_mutex);
bdev->bd_part = disk_get_part(disk, bdev->bd_partno);
if (!(disk->flags & GENHD_FL_UP) ||
!bdev->bd_part || !bdev_nr_sectors(bdev)) {
!bdev_nr_sectors(bdev)) {
__blkdev_put(whole, mode, 1);
bdput(whole);
ret = -ENXIO;
goto out_clear;
return -ENXIO;
}
set_init_blocksize(bdev);
}
@ -1336,7 +1333,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode)
bdev->bd_bdi = bdi_get(disk->queue->backing_dev_info);
} else {
if (!bdev_is_partition(bdev)) {
ret = 0;
if (bdev->bd_disk->fops->open)
ret = bdev->bd_disk->fops->open(bdev, mode);
/* the same as first opener case, read comment there */
@ -1349,11 +1345,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode)
}
bdev->bd_openers++;
return 0;
out_clear:
disk_put_part(bdev->bd_part);
bdev->bd_part = NULL;
return ret;
}
struct block_device *blkdev_get_no_open(dev_t dev)
@ -1580,18 +1571,12 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
sync_blockdev(bdev);
kill_bdev(bdev);
bdev_write_inode(bdev);
if (!bdev_is_partition(bdev) && disk->fops->release)
disk->fops->release(disk, mode);
disk_put_part(bdev->bd_part);
bdev->bd_part = NULL;
if (bdev_is_partition(bdev))
victim = bdev_whole(bdev);
} else {
if (!bdev_is_partition(bdev) && disk->fops->release)
disk->fops->release(disk, mode);
}
if (!bdev_is_partition(bdev) && disk->fops->release)
disk->fops->release(disk, mode);
mutex_unlock(&bdev->bd_mutex);
if (victim) {
__blkdev_put(victim, mode, 1);

2
include/linux/blk_types.h
View File

@ -59,7 +59,7 @@ struct block_device {
} __randomize_layout;
#define bdev_whole(_bdev) \
((_bdev)->bd_disk->part0.bdev)
((_bdev)->bd_disk->part0)
#define bdev_kobj(_bdev) \
(&part_to_dev((_bdev)->bd_part)->kobj)

14
include/linux/genhd.h
View File

@ -19,11 +19,12 @@
#include <linux/blk_types.h>
#include <asm/local.h>
#define dev_to_disk(device) container_of((device), struct gendisk, part0.__dev)
#define dev_to_part(device) container_of((device), struct hd_struct, __dev)
#define disk_to_dev(disk) (&(disk)->part0.__dev)
#define part_to_dev(part) (&((part)->__dev))
#define dev_to_disk(device) (dev_to_part(device)->bdev->bd_disk)
#define disk_to_dev(disk) (part_to_dev((disk)->part0->bd_part))
extern const struct device_type disk_type;
extern struct device_type part_type;
extern struct class block_class;
@ -51,12 +52,9 @@ struct partition_meta_info {
};
struct hd_struct {
struct percpu_ref ref;
struct block_device *bdev;
struct device __dev;
int partno;
struct rcu_work rcu_work;
};
/**
@ -168,7 +166,7 @@ struct gendisk {
* helpers.
*/
struct disk_part_tbl __rcu *part_tbl;
struct hd_struct part0;
struct block_device *part0;
const struct block_device_operations *fops;
struct request_queue *queue;
@ -278,7 +276,7 @@ extern void set_disk_ro(struct gendisk *disk, int flag);
static inline int get_disk_ro(struct gendisk *disk)
{
return disk->part0.bdev->bd_read_only;
return disk->part0->bd_read_only;
}
extern void disk_block_events(struct gendisk *disk);
@ -302,7 +300,7 @@ static inline sector_t bdev_nr_sectors(struct block_device *bdev)
static inline sector_t get_capacity(struct gendisk *disk)
{
return bdev_nr_sectors(disk->part0.bdev);
return bdev_nr_sectors(disk->part0);
}
int bdev_disk_changed(struct block_device *bdev, bool invalidate);

4
include/linux/part_stat.h
View File

@ -59,8 +59,8 @@ static inline void part_stat_set_all(struct hd_struct *part, int value)
#define part_stat_add(part, field, addnd) do { \
__part_stat_add((part), field, addnd); \
if ((part)->partno) \
__part_stat_add(&part_to_disk((part))->part0, \
field, addnd); \
__part_stat_add(part_to_disk((part))->part0->bd_part, \
field, addnd); \
} while (0)
#define part_stat_dec(part, field) \