From a869f7b0541174ee1e3b19df535cea0d29bbbbda Mon Sep 17 00:00:00 2001 From: Olga Kornievskaia Date: Tue, 20 Dec 2022 12:31:29 -0500 Subject: [PATCH] pNFS/filelayout: Fix coalescing test for single DS [ Upstream commit a6b9d2fa0024e7e399c26facd0fb466b7396e2b9 ] When there is a single DS no striping constraints need to be placed on the IO. When such constraint is applied then buffered reads don't coalesce to the DS's rsize. Signed-off-by: Olga Kornievskaia Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/filelayout/filelayout.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c index 98b74cdabb99..8c72718d9fe0 100644 --- a/fs/nfs/filelayout/filelayout.c +++ b/fs/nfs/filelayout/filelayout.c @@ -837,6 +837,12 @@ filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid, return &fl->generic_hdr; } +static bool +filelayout_lseg_is_striped(const struct nfs4_filelayout_segment *flseg) +{ + return flseg->num_fh > 1; +} + /* * filelayout_pg_test(). Called by nfs_can_coalesce_requests() * @@ -857,6 +863,8 @@ filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, size = pnfs_generic_pg_test(pgio, prev, req); if (!size) return 0; + else if (!filelayout_lseg_is_striped(FILELAYOUT_LSEG(pgio->pg_lseg))) + return size; /* see if req and prev are in the same stripe */ if (prev) {