From 309a1d65b11de24d172f7dbbc21583ebd649c912 Mon Sep 17 00:00:00 2001 From: Weston Andros Adamson Date: Fri, 5 Sep 2014 16:34:29 -0400 Subject: [PATCH] nfs: handle overlapping reqs in lock_and_join This is needed for mirrored DS support, where multuple requests cover the same range. Signed-off-by: Weston Andros Adamson --- fs/nfs/write.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 8800bd3b235d..e9974574b19a 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -473,13 +473,18 @@ try_again: do { /* * Subrequests are always contiguous, non overlapping - * and in order. If not, it's a programming error. + * and in order - but may be repeated (mirrored writes). */ - WARN_ON_ONCE(subreq->wb_offset != - (head->wb_offset + total_bytes)); - - /* keep track of how many bytes this group covers */ - total_bytes += subreq->wb_bytes; + if (subreq->wb_offset == (head->wb_offset + total_bytes)) { + /* keep track of how many bytes this group covers */ + total_bytes += subreq->wb_bytes; + } else if (WARN_ON_ONCE(subreq->wb_offset < head->wb_offset || + ((subreq->wb_offset + subreq->wb_bytes) > + (head->wb_offset + total_bytes)))) { + nfs_page_group_unlock(head); + spin_unlock(&inode->i_lock); + return ERR_PTR(-EIO); + } if (!nfs_lock_request(subreq)) { /* releases page group bit lock and -- 2.20.1