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| author | Trond Myklebust <trond.myklebust@primarydata.com> | 2017-02-02 12:26:38 -0500 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2018-05-31 15:03:12 -0400 |
| commit | 64294b08f9d27f83cbb0975250614864fa733bda (patch) | |
| tree | 5e342c641fba507f84a486b6ed6e47880bc82065 /fs/nfs | |
| parent | 8dc96566c0c34b8c2632bc6071dad208d69dd5b0 (diff) | |
| download | linux-64294b08f9d27f83cbb0975250614864fa733bda.tar.bz2 | |
pNFS: Don't send LAYOUTGET on OPEN for read, if we already have cached data
If we're only opening the file for reading, and the file is empty and/or
we already have cached data, then heuristically optimise away the
LAYOUTGET.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Diffstat (limited to 'fs/nfs')
| -rw-r--r-- | fs/nfs/pnfs.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index d5dc97f72b30..717cd95a0306 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -2046,6 +2046,11 @@ static void _lgopen_prepare_attached(struct nfs4_opendata *data, struct nfs4_layoutget *lgp; struct pnfs_layout_hdr *lo; + /* Heuristic: don't send layoutget if we have cached data */ + if (rng.iomode == IOMODE_READ && + (i_size_read(ino) == 0 || ino->i_mapping->nrpages != 0)) + return; + lo = _pnfs_grab_empty_layout(ino, ctx); if (!lo) return; |