Re: disk revalidation updates and OOM

[He Zhe <zhe.he@windriver.com>]

On 3/11/20 12:26 AM, Christoph Hellwig wrote:
> On Tue, Mar 10, 2020 at 11:30:27PM +0800, He Zhe wrote:
>>> So this is the exact requirement of commits to be reverted from a bisect
>>> or just a first guess?
>> Many commits failed to build or boot during bisection.
>>
>> At least the following four have to be reverted to make it work.
>>
>> 979c690d block: move clearing bd_invalidated into check_disk_size_change
>> f0b870d block: remove (__)blkdev_reread_part as an exported API
>> 142fe8f block: fix bdev_disk_changed for non-partitioned devices
>> a1548b6 block: move rescan_partitions to fs/block_dev.c
> Just to make sure we are on the same page:  if you revert all four it
> works, if you rever all but
>
> a1548b6 block: move rescan_partitions to fs/block_dev.c
>
> it doesn't?

After reverting 142fe8f, rescan_partitions would be called in block/ioctl.c
and cause a build failure. So I need to also revert a1548b6 to provide
rescan_partitions.

OR if I manually add the following diff instead of reverting a1548b6, then yes,
it works too.

diff --git a/block/ioctl.c b/block/ioctl.c
index 8d724d11c8f5..bac562604cd0 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -192,6 +192,7 @@ static int compat_blkpg_ioctl(struct block_device *bdev,
  * acquire bd_mutex. This API should be used in case that
  * caller has held bd_mutex already.
  */
+extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev, bool invalidate);
 int __blkdev_reread_part(struct block_device *bdev)
 {
        struct gendisk *disk = bdev->bd_disk;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index ec10dacd18d0..30da0bc85c31 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1508,7 +1508,7 @@ 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,
+int rescan_partitions(struct gendisk *disk, struct block_device *bdev,
                bool invalidate)
 {
        int ret;


Zhe