Re: [PATCH 1/1] pNFS/filelayout: Fix coalescing test for single DS
From: Trond Myklebust <hidden>
Date: 2022-12-20 16:38:46
quoted hunk ↗ jump to hunk
On Dec 20, 2022, at 11:29, Olga Kornievskaia [off-list ref] wrote: 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 <redacted> --- fs/nfs/filelayout/filelayout.c | 2 ++ fs/nfs/filelayout/filelayout.h | 1 + fs/nfs/filelayout/filelayoutdev.c | 4 +++- 3 files changed, 6 insertions(+), 1 deletion(-)diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c index ad34a33b0737..cd819b795935 100644 --- a/fs/nfs/filelayout/filelayout.c +++ b/fs/nfs/filelayout/filelayout.c@@ -803,6 +803,8 @@ 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(pgio->pg_lseg)->single_ds) + return size;
Hmm… Instead of adding the boolean, perhaps just add a helper function
static bool filelayout_lseg_is_striped(const struct nfs4_filelayout_segment *flseg)
{
return flseg->num_fh > 1;
}
that can be called here?
quoted hunk ↗ jump to hunk
/* see if req and prev are in the same stripe */ if (prev) {diff --git a/fs/nfs/filelayout/filelayout.h b/fs/nfs/filelayout/filelayout.h index aed0748fd6ec..524920c2cbf8 100644 --- a/fs/nfs/filelayout/filelayout.h +++ b/fs/nfs/filelayout/filelayout.h@@ -65,6 +65,7 @@ struct nfs4_filelayout_segment {struct nfs4_file_layout_dsaddr *dsaddr; /* Point to GETDEVINFO data */ unsigned int num_fh; struct nfs_fh **fh_array; + bool single_ds; }; struct nfs4_filelayout {diff --git a/fs/nfs/filelayout/filelayoutdev.c b/fs/nfs/filelayout/filelayoutdev.c index acf4b88889dc..95ebbe9e7ed4 100644 --- a/fs/nfs/filelayout/filelayoutdev.c +++ b/fs/nfs/filelayout/filelayoutdev.c@@ -243,8 +243,10 @@ nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j)u32 i; if (flseg->stripe_type == STRIPE_SPARSE) { - if (flseg->num_fh == 1) + if (flseg->num_fh == 1) { + flseg->single_ds = true; i = 0; + } else if (flseg->num_fh == 0) /* Use the MDS OPEN fh set in nfs_read_rpcsetup */ return NULL; -- 2.31.1
_________________________________ Trond Myklebust Linux NFS client maintainer, Hammerspace trond.myklebust@hammerspace.com