[PATCH 12/45] block: add a bdev_kobj helper

Christoph Hellwig
2020-11-28T22:09:05Z

Add a little helper to find the kobject for a struct block_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Coly Li <colyli@suse.de> [bcache]
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
---
drivers/md/bcache/super.c | 7 ++-----
drivers/md/md.c | 4 +---
fs/block_dev.c | 6 +++---
fs/btrfs/sysfs.c | 15 +++------------
include/linux/blk_types.h | 3 +++
5 files changed, 12 insertions(+), 23 deletions(-)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 46a00134a36ae1..a6a5e21e4fd136 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1447,8 +1447,7 @@ static int register_bdev(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
goto err;

err = "error creating kobject";
- if (kobject_add(&dc->disk.kobj, &part_to_dev(bdev->bd_part)->kobj,
- "bcache"))
+ if (kobject_add(&dc->disk.kobj, bdev_kobj(bdev), "bcache"))
goto err;
if (bch_cache_accounting_add_kobjs(&dc->accounting, &dc->disk.kobj))
goto err;
@@ -2342,9 +2341,7 @@ static int register_cache(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
goto err;
}

- if (kobject_add(&ca->kobj,
- &part_to_dev(bdev->bd_part)->kobj,
- "bcache")) {
+ if (kobject_add(&ca->kobj, bdev_kobj(bdev), "bcache")) {
err = "error calling kobject_add";
ret = -ENOMEM;
goto out;
diff --git a/drivers/md/md.c b/drivers/md/md.c
index b2edf5e0f965b5..7ce6047c856ea2 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2414,7 +2414,6 @@ EXPORT_SYMBOL(md_integrity_add_rdev);
static int bind_rdev_to_array(struct md_rdev *rdev, struct mddev *mddev)
{
char b[BDEVNAME_SIZE];
- struct kobject *ko;
int err;

/* prevent duplicates */
@@ -2477,9 +2476,8 @@ static int bind_rdev_to_array(struct md_rdev *rdev, struct mddev *mddev)
if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
goto fail;

- ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
/* failure here is OK */
- err = sysfs_create_link(&rdev->kobj, ko, "block");
+ err = sysfs_create_link(&rdev->kobj, bdev_kobj(rdev->bdev), "block");
rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
rdev->sysfs_unack_badblocks =
sysfs_get_dirent_safe(rdev->kobj.sd, "unacknowledged_bad_blocks");
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 33c29106c98907..c5755150c6be62 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1242,7 +1242,7 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
holder->disk = disk;
holder->refcnt = 1;

- ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+ ret = add_symlink(disk->slave_dir, bdev_kobj(bdev));
if (ret)
goto out_free;

@@ -1259,7 +1259,7 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
goto out_unlock;

out_del:
- del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+ del_symlink(disk->slave_dir, bdev_kobj(bdev));
out_free:
kfree(holder);
out_unlock:
@@ -1287,7 +1287,7 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
holder = bd_find_holder_disk(bdev, disk);

if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) {
- del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+ del_symlink(disk->slave_dir, bdev_kobj(bdev));
del_symlink(bdev->bd_part->holder_dir,
&disk_to_dev(disk)->kobj);
kobject_put(bdev->bd_part->holder_dir);
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 279d9262b676d4..24b6c6dc69000a 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -1232,8 +1232,6 @@ int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,

void btrfs_sysfs_remove_device(struct btrfs_device *device)
{
- struct hd_struct *disk;
- struct kobject *disk_kobj;
struct kobject *devices_kobj;

/*
@@ -1243,11 +1241,8 @@ void btrfs_sysfs_remove_device(struct btrfs_device *device)
devices_kobj = device->fs_info->fs_devices->devices_kobj;
ASSERT(devices_kobj);

- if (device->bdev) {
- disk = device->bdev->bd_part;
- disk_kobj = &part_to_dev(disk)->kobj;
- sysfs_remove_link(devices_kobj, disk_kobj->name);
- }
+ if (device->bdev)
+ sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);

if (device->devid_kobj.state_initialized) {
kobject_del(&device->devid_kobj);
@@ -1353,11 +1348,7 @@ int btrfs_sysfs_add_device(struct btrfs_device *device)
nofs_flag = memalloc_nofs_save();

if (device->bdev) {
- struct hd_struct *disk;
- struct kobject *disk_kobj;
-
- disk = device->bdev->bd_part;
- disk_kobj = &part_to_dev(disk)->kobj;
+ struct kobject *disk_kobj = bdev_kobj(device->bdev);

ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
if (ret) {
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index ebfb4e7c1fd125..9698f459cc65c9 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -49,6 +49,9 @@ struct block_device {
struct super_block *bd_fsfreeze_sb;
} __randomize_layout;

+#define bdev_kobj(_bdev) \
+ (&part_to_dev((_bdev)->bd_part)->kobj)
+
/*
* Block error status values. See block/blk-core:blk_errors for the details.
* Alpha cannot write a byte atomically, so we need to use 32-bit value.
--
2.29.2