block: also call ->open for incremental partition opens

For whole devices ->open is called for each open, but for partitions it
is only called on the first open of a partition, e.g.:

  open("/dev/vdb", ...)
  open("/dev/vdb", ...)
    - 2 call to ->open

  open("/dev/vdb1", ...)
  open("/dev/vdb", ...)
    - 2 call to ->open

  open("/dev/vdb", ...)
  open("/dev/vdb", ...)
    - just open call to ->open

This is problematic as various block drivers look at open flags and
might not do all the required setup if the earlier open was with an
odd flag like O_NDELAY or the magic 3 ioctl-only open mode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phillip Potter <phil@philpotter.co.uk>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2023-06-08 13:02:29 +02:00 committed by Jens Axboe
parent fece685cc7
commit 9d1c92872e

View file

@ -683,9 +683,6 @@ static int blkdev_get_part(struct block_device *part, fmode_t mode)
struct gendisk *disk = part->bd_disk;
int ret;
if (atomic_read(&part->bd_openers))
goto done;
ret = blkdev_get_whole(bdev_whole(part), mode);
if (ret)
return ret;
@ -694,9 +691,10 @@ static int blkdev_get_part(struct block_device *part, fmode_t mode)
if (!bdev_nr_sectors(part))
goto out_blkdev_put;
disk->open_partitions++;
set_init_blocksize(part);
done:
if (!atomic_read(&part->bd_openers)) {
disk->open_partitions++;
set_init_blocksize(part);
}
atomic_inc(&part->bd_openers);
return 0;
@ -709,10 +707,10 @@ static void blkdev_put_part(struct block_device *part, fmode_t mode)
{
struct block_device *whole = bdev_whole(part);
if (!atomic_dec_and_test(&part->bd_openers))
return;
blkdev_flush_mapping(part);
whole->bd_disk->open_partitions--;
if (atomic_dec_and_test(&part->bd_openers)) {
blkdev_flush_mapping(part);
whole->bd_disk->open_partitions--;
}
blkdev_put_whole(whole, mode);
}