Hi Trond,
shouldn't this go to stable as well?
Tigran.
----- Original Message -----
> From: "Trond Myklebust" <trondmy@xxxxxxxxx>
> To: "Anna Schumaker" <Anna.Schumaker@xxxxxxxxxx>
> Cc: "linux-nfs" <linux-nfs@xxxxxxxxxxxxxxx>
> Sent: Friday, August 17, 2018 4:31:08 PM
> Subject: [PATCH] pNFS/flexfiles: ff_layout_pg_init_read should exit on error
> From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
>
> If we get an error while retrieving the layout, then we should
> report it rather than falling back to I/O through the MDS.
>
> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> ---
> fs/nfs/flexfilelayout/flexfilelayout.c | 28 ++++++++++----------------
> 1 file changed, 11 insertions(+), 17 deletions(-)
>
> diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c
> b/fs/nfs/flexfilelayout/flexfilelayout.c
> index 280b6b060d53..cae43333ef16 100644
> --- a/fs/nfs/flexfilelayout/flexfilelayout.c
> +++ b/fs/nfs/flexfilelayout/flexfilelayout.c
> @@ -812,7 +812,6 @@ ff_layout_pg_get_read(struct nfs_pageio_descriptor *pgio,
> struct nfs_page *req,
> bool strict_iomode)
> {
> -retry_strict:
> pnfs_put_lseg(pgio->pg_lseg);
> pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
> req->wb_context,
> @@ -825,16 +824,6 @@ ff_layout_pg_get_read(struct nfs_pageio_descriptor *pgio,
> pgio->pg_error = PTR_ERR(pgio->pg_lseg);
> pgio->pg_lseg = NULL;
> }
> -
> - /* If we don't have checking, do get a IOMODE_RW
> - * segment, and the server wants to avoid READs
> - * there, then retry!
> - */
> - if (pgio->pg_lseg && !strict_iomode &&
> - ff_layout_avoid_read_on_rw(pgio->pg_lseg)) {
> - strict_iomode = true;
> - goto retry_strict;
> - }
> }
>
> static void
> @@ -849,14 +838,16 @@ ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio,
> retry:
> pnfs_generic_pg_check_layout(pgio);
> /* Use full layout for now */
> - if (!pgio->pg_lseg)
> + if (!pgio->pg_lseg) {
> ff_layout_pg_get_read(pgio, req, false);
> - else if (ff_layout_avoid_read_on_rw(pgio->pg_lseg))
> + if (!pgio->pg_lseg)
> + goto out_nolseg;
> + }
> + if (ff_layout_avoid_read_on_rw(pgio->pg_lseg)) {
> ff_layout_pg_get_read(pgio, req, true);
> -
> - /* If no lseg, fall back to read through mds */
> - if (pgio->pg_lseg == NULL)
> - goto out_mds;
> + if (!pgio->pg_lseg)
> + goto out_nolseg;
> + }
>
> ds = ff_layout_choose_best_ds_for_read(pgio->pg_lseg, 0, &ds_idx);
> if (!ds) {
> @@ -878,6 +869,9 @@ ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio,
> pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].rsize;
>
> return;
> +out_nolseg:
> + if (pgio->pg_error < 0)
> + return;
> out_mds:
> pnfs_put_lseg(pgio->pg_lseg);
> pgio->pg_lseg = NULL;
> --
> 2.17.1
