4.4-stable review patch. If anyone has any objections, please let me know.
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From: Benjamin Coddington bcodding@redhat.com
[ Upstream commit 43b7d964ed30dbca5c83c90cb010985b429ec4f9 ]
Commit a7d42ddb3099727f58366fa006f850a219cce6c8 ("nfs: add mirroring support to pgio layer") moved pg_cleanup out of the path when there was non-sequental I/O that needed to be flushed. The result is that for layouts that have more than one layout segment per file, the pg_lseg is not cleared, so we can end up hitting the WARN_ON_ONCE(req_start >= seg_end) in pnfs_generic_pg_test since the pg_lseg will be pointing to that previously-flushed layout segment.
Signed-off-by: Benjamin Coddington bcodding@redhat.com Fixes: a7d42ddb3099 ("nfs: add mirroring support to pgio layer") Signed-off-by: Trond Myklebust trond.myklebust@primarydata.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/nfs/pagelist.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -1273,8 +1273,10 @@ void nfs_pageio_cond_complete(struct nfs mirror = &desc->pg_mirrors[midx]; if (!list_empty(&mirror->pg_list)) { prev = nfs_list_entry(mirror->pg_list.prev); - if (index != prev->wb_index + 1) - nfs_pageio_complete_mirror(desc, midx); + if (index != prev->wb_index + 1) { + nfs_pageio_complete(desc); + break; + } } } }