On 05/02/2016 09:10 PM, Dan Williams wrote: <> > > The semantic I am talking about preserving is: > > buffered / unaligned write of a bad sector => -EIO on reading into the > page cache > What about aligned buffered write? like write 0-to-eof This still broken? (and is what restore apps do) > ...and that the only guaranteed way to clear an error (assuming the > block device supports it) is an O_DIRECT write. > Sure fixing dax_do_io will guaranty that. <> > I still think we're talking past each other on this point. Yes we are! > This patch > set is not overloading error semantics, it's fixing the error handling > problem that was introduced in this commit: > > d475c6346a38 dax,ext2: replace XIP read and write with DAX I/O > > ...where we started overloading O_DIRECT and dax_do_io() semantics. > But above does not fix them does it? it just completely NULLs DAX for O_DIRECT which is a great pity, why did we do all this work in the first place. And then it keeps broken the aligned buffered writes, which are still broken after this set. I have by now read the v2 patches. And I think you guys did not yet try the proper fix for dax_do_io. I think you need to go deeper into the loops and selectively call bdev_* when error on a specific page copy. No need to go through direct_IO path at all. Do you need that I send you a patch to demonstrate what I mean? But yes I feel too that "we're talking past each other". I did want to come to LSF and talk to you, but was not invited. Should I call you? Thanks Boaz -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>