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. 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 -- 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
