NFS: Relax requirements in nfs_flush_incompatible

If two processes share the same credentials and NFSv4 open stateid, then
allow them both to dirty the same page, even if their nfs_open_context
differs.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

3 files changed, 8 insertions, 7 deletions

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 99a2919047e9..870e2ba7ba49 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -264,6 +264,12 @@ static inline bool nfs_pgio_has_mirroring(struct nfs_pageio_descriptor *desc)
         return desc->pg_mirror_count > 1;
 }
 
+static inline bool nfs_match_open_context(const struct nfs_open_context *ctx1,
+                const struct nfs_open_context *ctx2)
+{
+        return ctx1->cred == ctx2->cred && ctx1->state == ctx2->state;
+}
+
 /* nfs2xdr.c */
 extern struct rpc_procinfo nfs_procedures[];
 extern int nfs2_decode_dirent(struct xdr_stream *,
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 452a011ba0d8..c3a78450a239 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -903,12 +903,6 @@ static void nfs_pageio_cleanup_mirroring(struct nfs_pageio_descriptor *pgio)
         pgio->pg_mirrors_dynamic = NULL;
 }
 
-static bool nfs_match_open_context(const struct nfs_open_context *ctx1,
-                const struct nfs_open_context *ctx2)
-{
-        return ctx1->cred == ctx2->cred && ctx1->state == ctx2->state;
-}
-
 static bool nfs_match_lock_context(const struct nfs_lock_context *l1,
                 const struct nfs_lock_context *l2)
 {
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 0aa8d6f23b4c..2c26e04d9396 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1130,7 +1130,8 @@ int nfs_flush_incompatible(struct file *file, struct page *page)
                 if (req == NULL)
                         return 0;
                 l_ctx = req->wb_lock_context;
-                do_flush = req->wb_page != page || req->wb_context != ctx;
+                do_flush = req->wb_page != page ||
+                        !nfs_match_open_context(req->wb_context, ctx);
                 /* for now, flush if more than 1 request in page_group */
                 do_flush |= req->wb_this_page != req;
                 if (l_ctx && flctx &&