mainline inclusion from mainline-v5.10-rc2 commit b40813ddcd6b category: bugfix bugzilla: 1891363 CVE: NA
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Mounted NBD device can be resized, one use case is rbd-nbd.
Fix the issue by setting up default block size, then not touch it in nbd_size_update() any more. This kind of usage is aligned with loop which has same use case too.
Cc: stable@vger.kernel.org Fixes: c8a83a6b54d0 ("nbd: Use set_blocksize() to set device blocksize") Reported-by: lining lining2020x@163.com Signed-off-by: Ming Lei ming.lei@redhat.com Cc: Josef Bacik josef@toxicpanda.com Cc: Jan Kara jack@suse.cz Tested-by: lining lining2020x@163.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: lining lining_yewu@cmss.chinamobile.com --- drivers/block/nbd.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 816188aa841f..a913153d0b6b 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -293,7 +293,7 @@ static void nbd_size_clear(struct nbd_device *nbd) } }
-static void nbd_size_update(struct nbd_device *nbd) +static void nbd_size_update(struct nbd_device *nbd, bool start) { struct nbd_config *config = nbd->config; struct block_device *bdev = bdget_disk(nbd->disk, 0); @@ -309,7 +309,8 @@ static void nbd_size_update(struct nbd_device *nbd) if (bdev) { if (bdev->bd_disk) { bd_set_size(bdev, config->bytesize); - set_blocksize(bdev, config->blksize); + if (start) + set_blocksize(bdev, config->blksize); } else bdev->bd_invalidated = 1; bdput(bdev); @@ -324,7 +325,7 @@ static void nbd_size_set(struct nbd_device *nbd, loff_t blocksize, config->blksize = blocksize; config->bytesize = blocksize * nr_blocks; if (nbd->task_recv != NULL) - nbd_size_update(nbd); + nbd_size_update(nbd, false); }
static void nbd_complete_rq(struct request *req) @@ -1263,7 +1264,7 @@ static int nbd_start_device(struct nbd_device *nbd) args->index = i; queue_work(nbd->recv_workq, &args->work); } - nbd_size_update(nbd); + nbd_size_update(nbd, true); return error; }
-- 2.25.1