On Fri, Nov 27, 2020 at 01:45:37PM +0100, Jan Kara wrote: > > At this point the hd_struct is already allocated together with the > > block_device, and thus only freed after the last block_device reference > > goes away plus the inode freeing RCU grace period. So the device model > > ref to part is indeed gone, but that simply does not matter any more. > > Well, but once device model ref to part is gone, we're going to free the > bdev inode ref as well. Thus there's nothing which pins the bdev containing > hd_struct? > > But now as I'm thinking about it you later switch the device model reference > to just pure inode reference and use igrab() which will reliably return > NULL if the inode is on it's way to be destroyed so probably we are safe in > the final state. igrab always succeeds. But we should switch to a tryget.
