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| author | Christian Brauner <brauner@kernel.org> | 2023-10-17 20:48:19 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2023-10-28 13:29:22 +0200 |
| commit | c30b9787a48118d2ed0283b6c8f2abee873a1d19 (patch) | |
| tree | adafb91c07c4961716068a9cdbf5063d4f7dce10 /block | |
| parent | fs: Avoid grabbing sb->s_umount under bdev->bd_holder_lock (diff) | |
| download | linux-c30b9787a48118d2ed0283b6c8f2abee873a1d19.tar.xz linux-c30b9787a48118d2ed0283b6c8f2abee873a1d19.zip | |
block: simplify bdev_del_partition()
BLKPG_DEL_PARTITION refuses to delete partitions that still have
openers, i.e., that has an elevated @bdev->bd_openers count. If a device
is claimed by setting @bdev->bd_holder and @bdev->bd_holder_ops
@bdev->bd_openers and @bdev->bd_holders are incremented.
@bdev->bd_openers is effectively guaranteed to be >= @bdev->bd_holders.
So as long as @bdev->bd_openers isn't zero we know that this partition
is still in active use and that there might still be @bdev->bd_holder
and @bdev->bd_holder_ops set.
The only current example is @fs_holder_ops for filesystems. But that
means bdev_mark_dead() which calls into
bdev->bd_holder_ops->mark_dead::fs_bdev_mark_dead() is a nop. As long as
there's an elevated @bdev->bd_openers count we can't delete the
partition and if there isn't an elevated @bdev->bd_openers count then
there's no @bdev->bd_holder or @bdev->bd_holder_ops.
So simply open-code what we need to do. This gets rid of one more
instance where we acquire s_umount under @disk->open_mutex.
Link: https://lore.kernel.org/r/20231016-fototermin-umriss-59f1ea6c1fe6@brauner
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231017184823.1383356-2-hch@lst.de
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'block')
| -rw-r--r-- | block/partitions/core.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/block/partitions/core.c b/block/partitions/core.c index e137a87f4db0..b0585536b407 100644 --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -485,7 +485,18 @@ int bdev_del_partition(struct gendisk *disk, int partno) if (atomic_read(&part->bd_openers)) goto out_unlock; - delete_partition(part); + /* + * We verified that @part->bd_openers is zero above and so + * @part->bd_holder{_ops} can't be set. And since we hold + * @disk->open_mutex the device can't be claimed by anyone. + * + * So no need to call @part->bd_holder_ops->mark_dead() here. + * Just delete the partition and invalidate it. + */ + + remove_inode_hash(part->bd_inode); + invalidate_bdev(part); + drop_partition(part); ret = 0; out_unlock: mutex_unlock(&disk->open_mutex); |