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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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

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) \