This is a note to let you know that I've just added the patch titled
block: fix scan partition for exclusively open device again
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
block-fix-scan-partition-for-exclusively-open-device-again.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e5cfefa97bccf956ea0bb6464c1f6c84fd7a8d9f Mon Sep 17 00:00:00 2001
From: Yu Kuai <yukuai3@xxxxxxxxxx>
Date: Fri, 17 Feb 2023 10:22:00 +0800
Subject: block: fix scan partition for exclusively open device again
From: Yu Kuai <yukuai3@xxxxxxxxxx>
commit e5cfefa97bccf956ea0bb6464c1f6c84fd7a8d9f upstream.
As explained in commit 36369f46e917 ("block: Do not reread partition table
on exclusively open device"), reread partition on the device that is
exclusively opened by someone else is problematic.
This patch will make sure partition scan will only be proceed if current
thread open the device exclusively, or the device is not opened
exclusively, and in the later case, other scanners and exclusive openers
will be blocked temporarily until partition scan is done.
Fixes: 10c70d95c0f2 ("block: remove the bd_openers checks in blk_drop_partitions")
Cc: <stable@xxxxxxxxxxxxxxx>
Suggested-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Link: https://lore.kernel.org/r/20230217022200.3092987-3-yukuai1@xxxxxxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
block/genhd.c | 30 ++++++++++++++++++++++++++----
block/ioctl.c | 3 +--
2 files changed, 27 insertions(+), 6 deletions(-)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -359,6 +359,7 @@ EXPORT_SYMBOL_GPL(disk_uevent);
int disk_scan_partitions(struct gendisk *disk, fmode_t mode, void *owner)
{
struct block_device *bdev;
+ int ret = 0;
if (disk->flags & (GENHD_FL_NO_PART | GENHD_FL_HIDDEN))
return -EINVAL;
@@ -371,11 +372,27 @@ int disk_scan_partitions(struct gendisk
return -EBUSY;
set_bit(GD_NEED_PART_SCAN, &disk->state);
- bdev = blkdev_get_by_dev(disk_devt(disk), mode, NULL);
+ /*
+ * If the device is opened exclusively by current thread already, it's
+ * safe to scan partitons, otherwise, use bd_prepare_to_claim() to
+ * synchronize with other exclusive openers and other partition
+ * scanners.
+ */
+ if (!(mode & FMODE_EXCL)) {
+ ret = bd_prepare_to_claim(disk->part0, disk_scan_partitions);
+ if (ret)
+ return ret;
+ }
+
+ bdev = blkdev_get_by_dev(disk_devt(disk), mode & ~FMODE_EXCL, NULL);
if (IS_ERR(bdev))
- return PTR_ERR(bdev);
- blkdev_put(bdev, mode);
- return 0;
+ ret = PTR_ERR(bdev);
+ else
+ blkdev_put(bdev, mode);
+
+ if (!(mode & FMODE_EXCL))
+ bd_abort_claiming(disk->part0, disk_scan_partitions);
+ return ret;
}
/**
@@ -497,6 +514,11 @@ int __must_check device_add_disk(struct
if (ret)
goto out_unregister_bdi;
+ /* Make sure the first partition scan will be proceed */
+ if (get_capacity(disk) && !(disk->flags & GENHD_FL_NO_PART) &&
+ !test_bit(GD_SUPPRESS_PART_SCAN, &disk->state))
+ set_bit(GD_NEED_PART_SCAN, &disk->state);
+
bdev_add(disk->part0, ddev->devt);
if (get_capacity(disk))
disk_scan_partitions(disk, FMODE_READ, NULL);
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -528,8 +528,7 @@ static int blkdev_common_ioctl(struct fi
return -EACCES;
if (bdev_is_partition(bdev))
return -EINVAL;
- return disk_scan_partitions(bdev->bd_disk, mode & ~FMODE_EXCL,
- file);
+ return disk_scan_partitions(bdev->bd_disk, mode, file);
case BLKTRACESTART:
case BLKTRACESTOP:
case BLKTRACETEARDOWN:
Patches currently in stable-queue which might be from yukuai3@xxxxxxxxxx are
queue-6.2/block-fix-scan-partition-for-exclusively-open-device-again.patch
queue-6.2/blk-cgroup-dropping-parent-refcount-after-pd_free_fn.patch
queue-6.2/blk-cgroup-synchronize-pd_free_fn-from-blkg_free_wor.patch
queue-6.2/blk-iocost-fix-divide-by-0-error-in-calc_lcoefs.patch
