From: Christoph Hellwig <hch@lst.de>
Date: Thu, 22 Jul 2021 09:53:56 +0200
Subject: [PATCH] block: unhash the whole device inode earlier
Git-commit: d7a66574b34e0b354442140927f9b787efccabfd
Patch-mainline: v5.15-rc1
References: jsc#PED-1183
Unhash the whole device inode early in del_gendisk. This allows to
remove the first GENHD_FL_UP check in the open path as we simply
won't find a just removed inode. The second non-racy check after
taking open_mutex is still kept.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210722075402.983367-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
block/genhd.c | 7 +------
fs/block_dev.c | 2 +-
2 files changed, 2 insertions(+), 7 deletions(-)
diff --git a/block/genhd.c b/block/genhd.c
index 298ee78c1bda..716f5ca479ad 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -585,6 +585,7 @@ void del_gendisk(struct gendisk *disk)
disk_del_events(disk);
mutex_lock(&disk->open_mutex);
+ remove_inode_hash(disk->part0->bd_inode);
disk->flags &= ~GENHD_FL_UP;
blk_drop_partitions(disk);
mutex_unlock(&disk->open_mutex);
@@ -592,12 +593,6 @@ void del_gendisk(struct gendisk *disk)
fsync_bdev(disk->part0);
__invalidate_device(disk->part0, true);
- /*
- * Unhash the bdev inode for this device so that it can't be looked
- * up any more even if openers still hold references to it.
- */
- remove_inode_hash(disk->part0->bd_inode);
-
set_capacity(disk, 0);
if (!(disk->flags & GENHD_FL_HIDDEN)) {
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 9ef4f1fc2cb0..932f4034ad66 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1340,7 +1340,7 @@ struct block_device *blkdev_get_no_open(dev_t dev)
disk = bdev->bd_disk;
if (!kobject_get_unless_zero(&disk_to_dev(disk)->kobj))
goto bdput;
- if ((disk->flags & (GENHD_FL_UP | GENHD_FL_HIDDEN)) != GENHD_FL_UP)
+ if (disk->flags & GENHD_FL_HIDDEN)
goto put_disk;
if (!try_module_get(bdev->bd_disk->fops->owner))
goto put_disk;
--
2.35.3