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authorChristoph Hellwig <hch@lst.de>2020-11-26 20:47:17 +0300
committerJens Axboe <axboe@kernel.dk>2020-12-02 00:53:40 +0300
commitcb8432d650fe3be58bb962bc8e602dc405510327 (patch)
tree5e893d44ba2449080db89f00098f11259384a56a /block
parent83950d359010a493462d58c712b1124c877d1b3b (diff)
downloadlinux-cb8432d650fe3be58bb962bc8e602dc405510327.tar.xz
block: allocate struct hd_struct as part of struct bdev_inode
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>
Diffstat (limited to 'block')
-rw-r--r--block/blk-core.c16
-rw-r--r--block/blk-flush.c2
-rw-r--r--block/blk-merge.c2
-rw-r--r--block/blk.h21
-rw-r--r--block/genhd.c50
-rw-r--r--block/partitions/core.c67
6 files changed, 33 insertions, 125 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index d64ffcb6f9ae..9ea70275fc1c 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -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);
diff --git a/block/blk-flush.c b/block/blk-flush.c
index e32958f0b687..fcd0a60574df 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -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]);
diff --git a/block/blk-merge.c b/block/blk-merge.c
index bcf5e4580603..cb351ab9b77d 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -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);
}
}
diff --git a/block/blk.h b/block/blk.h
index 0bd4b58bcbaf..32ac41f7557f 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -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,
diff --git a/block/genhd.c b/block/genhd.c
index 2db1204920a9..c35b03dac5e5 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -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);
diff --git a/block/partitions/core.c b/block/partitions/core.c
index 060c1be13cd8..6d1fca193cbd 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -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);