On 2011-06-01 17:44, Weston Andros Adamson wrote: > > On Jun 1, 2011, at 1:47 AM, Boaz Harrosh wrote: > >> On 06/01/2011 06:18 AM, Weston Andros Adamson wrote: >>> Use nfs_generic_pg_test instead of pnfs_generic_pg_test. >>> >>> This fixes the BUG at fs/nfs/write.c:941 introduced by >>> 89a58e32d9105c01022a757fb32ddc3b51bf0025. >>> >>> I was able to trigger this BUG reliably using pynfs in pnfs mode, >>> by using dd(1) to write many small blocks. >>> >>> Signed-off-by: Weston Andros Adamson <dros@xxxxxxxxxx> >>> --- >>> Fix proposed by Trond. >>> >>> Benny- Does this make sense? >>> >>> fs/nfs/nfs4filelayout.c | 2 +- >>> fs/nfs/pagelist.c | 5 ++++- >>> include/linux/nfs_page.h | 3 ++- >>> 3 files changed, 7 insertions(+), 3 deletions(-) >>> >>> diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c >>> index 4269088..1c3bb72 100644 >>> --- a/fs/nfs/nfs4filelayout.c >>> +++ b/fs/nfs/nfs4filelayout.c >>> @@ -661,7 +661,7 @@ filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, >>> u64 p_stripe, r_stripe; >>> u32 stripe_unit; >>> >>> - if (!pnfs_generic_pg_test(pgio, prev, req)) >>> + if (!nfs_generic_pg_test(pgio, prev, req)) >>> return 0; >>> >> >> pnfs_generic_pg_test is the one that gets the layout. >> >> What you've done is revert to MDS IO >> >> Boaz > > Ah, you're right - I didn't even notice that! I usually confirm client -> DS communication with tcpdump. I was working for too long yesterday :) > > Patch: recalled. Discussion about a real fix: started. > > -dros I think the following should work: Benny git diff --stat -p -M fs/nfs/nfs4filelayout.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-) diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c index 4269088..9f1d445 100644 --- a/fs/nfs/nfs4filelayout.c +++ b/fs/nfs/nfs4filelayout.c @@ -661,6 +661,16 @@ filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, u64 p_stripe, r_stripe; u32 stripe_unit; + /* + * FIXME: ideally we should be able to coalesce all requests + * that are not block boundary aligned, but currently this + * is problematic for the case of bsize < PAGE_CACHE_SIZE, + * since nfs_flush_multi and nfs_pagein_multi assume you + * can have only one struct nfs_page. + */ + if (desc->pg_bsize < PAGE_SIZE) + return 0; + if (!pnfs_generic_pg_test(pgio, prev, req)) return 0; -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
