Commit a6b9d2fa authored by Olga Kornievskaia's avatar Olga Kornievskaia Committed by Trond Myklebust
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pNFS/filelayout: Fix coalescing test for single DS 



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: default avatarOlga Kornievskaia <kolga@netapp.com>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent b18cba09

fs/nfs/filelayout/filelayout.c

+8 −0
Original line number Diff line number Diff line
@@ -783,6 +783,12 @@ 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()

 *
@@ -803,6 +809,8 @@ 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) {