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authorYufen Yu <yuyufen@huawei.com>2021-06-10 10:32:41 +0800
committerJens Axboe <axboe@kernel.dk>2021-06-30 19:38:48 -0600
commitb5cfbd35eccaa0b532dc0d8a31e4d59b5e314c93 (patch)
treee89e3215f8ac48c6418f4401a4941a9a26016e96 /block
parentefee99e68e69d8a1966f3d426cc0cea73e32c6d7 (diff)
downloadlinux-b5cfbd35eccaa0b532dc0d8a31e4d59b5e314c93.tar.gz
block: check disk exist before trying to add partition
If disk have been deleted, we should return fail for ioctl
BLKPG_DEL_PARTITION. Otherwise, the directory /sys/class/block
may remain invalid symlinks file. The race as following:

blkdev_open
				del_gendisk
				    disk->flags &= ~GENHD_FL_UP;
				    blk_drop_partitions
blkpg_ioctl
    bdev_add_partition
    add_partition
        device_add
	    device_add_class_symlinks

ioctl may add_partition after del_gendisk() have tried to delete
partitions. Then, symlinks file will be created.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Link: https://lore.kernel.org/r/20210610023241.3646241-1-yuyufen@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/partitions/core.c23
1 files changed, 16 insertions, 7 deletions
diff --git a/block/partitions/core.c b/block/partitions/core.c
index 347c56a51d87..ed78cdfe054b 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -453,17 +453,26 @@ int bdev_add_partition(struct block_device *bdev, int partno,
 		sector_t start, sector_t length)
 {
 	struct block_device *part;
+	struct gendisk *disk = bdev->bd_disk;
+	int ret;
 
-	mutex_lock(&bdev->bd_disk->open_mutex);
-	if (partition_overlaps(bdev->bd_disk, start, length, -1)) {
-		mutex_unlock(&bdev->bd_disk->open_mutex);
-		return -EBUSY;
+	mutex_lock(&disk->open_mutex);
+	if (!(disk->flags & GENHD_FL_UP)) {
+		ret = -ENXIO;
+		goto out;
 	}
 
-	part = add_partition(bdev->bd_disk, partno, start, length,
+	if (partition_overlaps(disk, start, length, -1)) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	part = add_partition(disk, partno, start, length,
 			ADDPART_FLAG_NONE, NULL);
-	mutex_unlock(&bdev->bd_disk->open_mutex);
-	return PTR_ERR_OR_ZERO(part);
+	ret = PTR_ERR_OR_ZERO(part);
+out:
+	mutex_unlock(&disk->open_mutex);
+	return ret;
 }
 
 int bdev_del_partition(struct block_device *bdev, int partno)