On Thu, Mar 15, 2018 at 11:32:07AM +0100, Lukas Czerner wrote: > > And where the "cdcd" data is comming from ? Not from the > > "pwrite -S 1 0 64k" > > that's producing "0101". Ah, too much context switching. Makes me look like the village idiot... Ok, I just spent some time looking at this in detail (event traces, etc) and it is indeed as the test describes - an whole delalloc extent allocation on partial overwrite. THe partial overwrite is triggered by the fpunch/fzero code, and it appears the delalloc converison is not paying attention to the start offset of the writeback: xfs_writepage: dev 7:0 ino 0x7603 pgoff 0xf000 size 0x10000 delalloc 1 ..... xfs_alloc_near_greater: dev 7:0 agno 0 agbno 3784 minlen 16 maxlen 16 ..... xfs_write_extent: dev 7:0 ino 0x7603 offset 0 block 3784 count 16 flag 0 IOWs, as I've said from the start (based on the test description) this has nothing to do with the corruption issue CrashMonkey is creating. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
