On 1/14/20 10:09 PM, Christoph Hellwig wrote:

quoted

Currently there is a small race window as pointed out by Jan [2] where, when
ext4 tries to allocate a written block for mapped files and if DIO read is in
progress, then this may result into stale data read exposure problem.

Do we have a test case for the problem?

I am not very sure if we have it in xfstests, (since I guess, DIO read 
during mmap writes is not well supported anyways).
But sure I was anyway thinking of writing one for my unit testing. Till
now I was mainly following that theoretically it is possible, although
it may be hard to catch it practically.

Please add at very least the fsdevel and xfs lists to iomap patches.

Yes, sorry about that. Will cc' in next time.


-ritesh