This reverts commit 1a721de8489fa559ff4471f73c58bb74ac5580d3.
The commit 1a721de8489f ("block: don't add or resize partition on the disk with GENHD_FL_NO_PART") and the commit 7777f47f2ea6 ("block: Move checking GENHD_FL_NO_PART to bdev_add_partition()") used the flag GENHD_FL_NO_PART to prevent the add or resize of partitions in 5.15 stable kernels.But in these 5.15 kernels, this is giving an issue with the following error where the loop driver wants to create a partition when the partscan is disabled on the loop device:
dd if=/dev/zero of=loopDisk.dsk bs=1M count=1 seek=10240; losetup -f loopDisk.dsk;parted -s /dev/loop0 -- mklabel gpt mkpart primary 2048s 4096s 1+0 records in 1+0 records out 1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.0016293 s, 644 MB/s "" Error: Partition(s) 1 on /dev/loop0 have been written, but we have been unable to inform the kernel of the change, probably because it/they are in use. As a result, the old partition(s) will remain in use. You should reboot now before making further changes. "" If the partition scan is not enabled on the loop device, this flag GENHD_FL_NO_PART is getting set and when partition creation is tried, it returns an error EINVAL thereby preventing the creation of partitions. So, there is no such distinction between disabling of partition scan and partition creation.
Later in 6.xxx kernels, the commit b9684a71fca7 ("block, loop: support partitions without scanning") a new flag GD_SUPPRESS_PART_SCAN was introduced that just disables the partition scan and uses GENHD_FL_NO_PART only to prevent creating partition scan. So, the partition creationg can proceed with even if partition scan is disabled.
As the commit b9684a71fca7 ("block, loop: support partitions without scanning") is not available in 5.15 stable kernel, and since there is no distinction between disabling of "partition scan" and "partition creation", we need to revert the commits 1a721de8489f and 7777f47f2ea6 from 5.15 stable kernel to allow partition creation when partscan is disabled.
Cc: stable@vger.kernel.org Signed-off-by: Gulam Mohamed gulam.mohamed@oracle.com --- Changes in V2: - Added,in the second patch, the reason for reverting the patch - Added the linux stable version 5.15.y to the subject line - Added the version V2 to the subject line Links to V1: https://lore.kernel.org/all/20251117174315.367072-1-gulam.mohamed@oracle.com... https://lore.kernel.org/all/20251117174315.367072-2-gulam.mohamed@oracle.com... --- block/ioctl.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/block/ioctl.c b/block/ioctl.c index d25b84441237..a260e39e56a4 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -20,8 +20,6 @@ static int blkpg_do_ioctl(struct block_device *bdev, struct blkpg_partition p; sector_t start, length;
- if (disk->flags & GENHD_FL_NO_PART) - return -EINVAL; if (!capable(CAP_SYS_ADMIN)) return -EACCES; if (copy_from_user(&p, upart, sizeof(struct blkpg_partition)))