Re: [Lts-dev] 4.4.92/69f53f5d: regressions detected in project lkft/linux-stable-rc-4.4-oe

Hi!

I looked at this again and what I found is that there are multiple concurrent writers that each get a posix write lock and then write to overlapping portions of the file.

The blocks should not overlap for one kind of a lock, they overlap for different kind of locks though. So that posix write locks overlap with ofd read locks, etc.

So in the failing case it should look like:

| ofd read | ofd read | ofd read | | posix wr | posix wr | posix wr |

Since the ofd read lock blocks are starting at offset 0 and are write_size in size and the posix write locks are starting at offset write_size/4 and are as well write_size in size.

I tried to make sure that we do not have overlaping posix locks since in that case it's very easy to get a failure.