From: Jan Kara <jack@xxxxxxx>
commit 36369f46e91785688a5f39d7a5590e3f07981316 upstream.
Since commit 10c70d95c0f2 ("block: remove the bd_openers checks in
blk_drop_partitions") we allow rereading of partition table although
there are users of the block device. This has an undesirable consequence
that e.g. if sda and sdb are assembled to a RAID1 device md0 with
partitions, BLKRRPART ioctl on sda will rescan partition table and
create sda1 device. This partition device under a raid device confuses
some programs (such as libstorage-ng used for initial partitioning for
distribution installation) leading to failures.
Fix the problem refusing to rescan partitions if there is another user
that has the block device exclusively open.
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/all/20221130135344.2ul4cyfstfs3znxg@quack3
Fixes: 10c70d95c0f2 ("block: remove the bd_openers checks in blk_drop_partitions")
Signed-off-by: Jan Kara <jack@xxxxxxx>
Link: https://lore.kernel.org/r/20221130175653.24299-1-jack@xxxxxxx
[axboe: fold in followup fix]
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
block/blk.h | 2 +-
block/genhd.c | 7 +++++--
block/ioctl.c | 12 +++++++-----
3 files changed, 13 insertions(+), 8 deletions(-)
--- a/block/blk.h
+++ b/block/blk.h
@@ -436,7 +436,7 @@ static inline struct kmem_cache *blk_get
}
struct request_queue *blk_alloc_queue(int node_id, bool alloc_srcu);
-int disk_scan_partitions(struct gendisk *disk, fmode_t mode);
+int disk_scan_partitions(struct gendisk *disk, fmode_t mode, void *owner);
int disk_alloc_events(struct gendisk *disk);
void disk_add_events(struct gendisk *disk);
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -356,7 +356,7 @@ void disk_uevent(struct gendisk *disk, e
}
EXPORT_SYMBOL_GPL(disk_uevent);
-int disk_scan_partitions(struct gendisk *disk, fmode_t mode)
+int disk_scan_partitions(struct gendisk *disk, fmode_t mode, void *owner)
{
struct block_device *bdev;
@@ -366,6 +366,9 @@ int disk_scan_partitions(struct gendisk
return -EINVAL;
if (disk->open_partitions)
return -EBUSY;
+ /* Someone else has bdev exclusively open? */
+ if (disk->part0->bd_holder && disk->part0->bd_holder != owner)
+ return -EBUSY;
set_bit(GD_NEED_PART_SCAN, &disk->state);
bdev = blkdev_get_by_dev(disk_devt(disk), mode, NULL);
@@ -500,7 +503,7 @@ int __must_check device_add_disk(struct
bdev_add(disk->part0, ddev->devt);
if (get_capacity(disk))
- disk_scan_partitions(disk, FMODE_READ);
+ disk_scan_partitions(disk, FMODE_READ, NULL);
/*
* Announce the disk and partitions after all partitions are
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -467,9 +467,10 @@ static int blkdev_bszset(struct block_de
* user space. Note the separate arg/argp parameters that are needed
* to deal with the compat_ptr() conversion.
*/
-static int blkdev_common_ioctl(struct block_device *bdev, fmode_t mode,
- unsigned cmd, unsigned long arg, void __user *argp)
+static int blkdev_common_ioctl(struct file *file, fmode_t mode, unsigned cmd,
+ unsigned long arg, void __user *argp)
{
+ struct block_device *bdev = I_BDEV(file->f_mapping->host);
unsigned int max_sectors;
switch (cmd) {
@@ -527,7 +528,8 @@ static int blkdev_common_ioctl(struct bl
return -EACCES;
if (bdev_is_partition(bdev))
return -EINVAL;
- return disk_scan_partitions(bdev->bd_disk, mode & ~FMODE_EXCL);
+ return disk_scan_partitions(bdev->bd_disk, mode & ~FMODE_EXCL,
+ file);
case BLKTRACESTART:
case BLKTRACESTOP:
case BLKTRACETEARDOWN:
@@ -605,7 +607,7 @@ long blkdev_ioctl(struct file *file, uns
break;
}
- ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
+ ret = blkdev_common_ioctl(file, mode, cmd, arg, argp);
if (ret != -ENOIOCTLCMD)
return ret;
@@ -674,7 +676,7 @@ long compat_blkdev_ioctl(struct file *fi
break;
}
- ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
+ ret = blkdev_common_ioctl(file, mode, cmd, arg, argp);
if (ret == -ENOIOCTLCMD && disk->fops->compat_ioctl)
ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);
