[PATCH 4/5] block: fix bdev_disk_changed for non-partitioned devices

Christoph Hellwig
2019-11-06T15:14:51Z

We still have to set the capacity to 0 if invalidating or call
revalidate_disk if not even if the disk has no partitions. Fix
that by merging rescan_partitions into bdev_disk_changed and just
stubbing out blk_add_partitions and blk_drop_partitions for
non-partitioned devices.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/ioctl.c | 6 ++----
block/partition-generic.c | 5 +++++
fs/block_dev.c | 27 ++++++++-------------------
include/linux/genhd.h | 1 +
4 files changed, 16 insertions(+), 23 deletions(-)

diff --git a/block/ioctl.c b/block/ioctl.c
index 8a7e33ce2097..52380c337078 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -162,16 +162,14 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
*/
int __blkdev_reread_part(struct block_device *bdev)
{
- struct gendisk *disk = bdev->bd_disk;
-
- if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains)
+ if (!disk_part_scan_enabled(bdev->bd_disk) || bdev != bdev->bd_contains)
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;

lockdep_assert_held(&bdev->bd_mutex);

- return rescan_partitions(disk, bdev, false);
+ return bdev_disk_changed(bdev, false);
}
EXPORT_SYMBOL(__blkdev_reread_part);

diff --git a/block/partition-generic.c b/block/partition-generic.c
index 7a6e406ac490..387d7e3a6bc4 100644
--- a/block/partition-generic.c
+++ b/block/partition-generic.c
@@ -445,6 +445,8 @@ int blk_drop_partitions(struct gendisk *disk, struct block_device *bdev)
struct hd_struct *part;
int res;

+ if (!disk_part_scan_enabled(disk))
+ return 0;
if (bdev->bd_part_count || bdev->bd_super)
return -EBUSY;
res = invalidate_partition(disk, 0);
@@ -578,6 +580,9 @@ int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
struct parsed_partitions *state;
int ret = -EAGAIN, p, highest;

+ if (!disk_part_scan_enabled(disk))
+ return 0;
+
state = check_partition(disk, bdev);
if (!state)
return 0;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index f0710085e1f1..ae16466a67f7 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1508,9 +1508,9 @@ EXPORT_SYMBOL(bd_set_size);

static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);

-static int rescan_partitions(struct gendisk *disk, struct block_device *bdev,
- bool invalidate)
+int bdev_disk_changed(struct block_device *bdev, bool invalidate)
{
+ struct gendisk *disk = bdev->bd_disk;
int ret;

rescan:
@@ -1526,30 +1526,19 @@ static int rescan_partitions(struct gendisk *disk, struct block_device *bdev,
check_disk_size_change(disk, bdev, !invalidate);
bdev->bd_invalidated = 0;

- if (!get_capacity(disk)) {
+ if (get_capacity(disk)) {
+ ret = blk_add_partitions(disk, bdev);
+ if (ret == -EAGAIN)
+ goto rescan;
+ } else {
/*
* Tell userspace that the media / partition table may have
* changed.
*/
kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
- return 0;
}
-
- ret = blk_add_partitions(disk, bdev);
- if (ret == -EAGAIN)
- goto rescan;
- return ret;
-}

-
-static void bdev_disk_changed(struct block_device *bdev, bool invalidate)
-{
- if (disk_part_scan_enabled(bdev->bd_disk)) {
- rescan_partitions(bdev->bd_disk, bdev, invalidate);
- } else {
- check_disk_size_change(bdev->bd_disk, bdev, !invalidate);
- bdev->bd_invalidated = 0;
- }
+ return ret;
}

/*
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index f5cffbf63abf..8bb63027e4d6 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -621,6 +621,7 @@ extern void blk_invalidate_devt(dev_t devt);
extern dev_t blk_lookup_devt(const char *name, int partno);
extern char *disk_name (struct gendisk *hd, int partno, char *buf);

+int bdev_disk_changed(struct block_device *bdev, bool invalidate);
int blk_add_partitions(struct gendisk *disk, struct block_device *bdev);
int blk_drop_partitions(struct gendisk *disk, struct block_device *bdev);
extern int disk_expand_part_tbl(struct gendisk *disk, int target);
--
2.20.1