On Tue, Dec 6, 2011 at 11:08 AM, Yongqiang Yang <xiaoqiangnk@xxxxxxxxx> wrote: > Hi Allison, > > I noticed another problem which has nothing to do with punching hole. > __block_write_begin does not zero buffers beyond EOF.(I guess you > tried to zero them in your code, am I right? ) When users mapread > beyond EOF, users get non-zero data. I am not sure zero or non-zero > data should be, but fsx thinks they should be zero data and reports an > error. > > It I understand the problem right, it happens more often with punch hole. Strange! filemap_fault should have handled the case. Yongqiang. > > Yongqiang. > On Tue, Dec 6, 2011 at 9:40 AM, Allison Henderson > <achender@xxxxxxxxxxxxxxxxxx> wrote: >> On 12/05/2011 04:38 PM, Hugh Dickins wrote: >>> >>> On Mon, 21 Nov 2011, Hugh Dickins wrote: >>>> >>>> On Mon, 21 Nov 2011, Ted Ts'o wrote: >>>>> >>>>> On Sun, Nov 20, 2011 at 12:59:10PM -0800, Hugh Dickins wrote: >>>>>> >>>>>> On Tue, 8 Nov 2011, Curt Wohlgemuth wrote: >>>>>> It appears that there's a bug with this patch: >>> >>> >>> This has been outstanding for a month now, and we've heard no progress: >>> please revert commit 02fac1297eb3 "ext4: fix partial page writes" for rc5. >>> >>> The problems appear on a 1k-blocksize filesystem under memory pressure: >>> the hunk in ext4_da_write_end() causes oops, because it's playing with >>> a page after generic_write_end() dropped our last reference to it; and >>> backing out the hunk in ext4_da_write_begin() is then found to stop >>> rare data corruption seen when kbuilding. >>> >>> Although I earlier reported that backing out the patch caused an fsx >>> test to fail earlier, I've since found great variation in how soon it >>> fails, and seen it fail just as quickly with 02fac1297eb3 still in. >>> I also reported that I had to go back to 2.6.38 for fsx not to fail >>> under memory pressure: you won't be surprised that that turned out to >>> be because 2.6.38 defaults nomblk_io_submit but 2.6.39 mblk_io_submit. >>> >>> Thanks, >>> Hugh >>> >> >> >> Hi there, >> >> Have you tried Yongqiang's patch "[PATCH 1/2] ext4: let mpage_submit_io >> works well when blocksize < pagesize" ? I have tried it and it does seem to >> help, but I am still running into some failures that I am trying to debug, >> but let please let us know if it helps the issues that you are seeing. Thx! >> >> Allison Henderson >> > > > > -- > Best Wishes > Yongqiang Yang -- Best Wishes Yongqiang Yang -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
