Return-Path: Received: from mail-it0-f66.google.com ([209.85.214.66]:33613 "EHLO mail-it0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751691AbcH2TYA (ORCPT ); Mon, 29 Aug 2016 15:24:00 -0400 Received: by mail-it0-f66.google.com with SMTP id n75so68059ith.0 for ; Mon, 29 Aug 2016 12:24:00 -0700 (PDT) From: Trond Myklebust To: linux-nfs@vger.kernel.org Subject: [PATCH] pNFS/flexfiles: Fix an Oopsable condition when connection to the DS fails Date: Mon, 29 Aug 2016 15:23:26 -0400 Message-Id: <1472498606-29926-1-git-send-email-trond.myklebust@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: If the attempt to connect to a DS fails inside ff_layout_pg_init_read or ff_layout_pg_init_write, then we currently end up clearing the layout segment carried by the struct nfs_pageio_descriptor, causing an Oops when we later call into ff_layout_read_pagelist/ff_layout_write_pagelist. The fix is to ensure we return the layout and then retry. Fixes: 446ca2195303 ("pNFS/flexfiles: When initing reads or writes, we...") Cc: stable@vger.kernel.org # v4.7+ Signed-off-by: Trond Myklebust --- fs/nfs/flexfilelayout/flexfilelayout.c | 37 +++++++++++++++---------------- fs/nfs/flexfilelayout/flexfilelayoutdev.c | 19 ++++++++-------- 2 files changed, 28 insertions(+), 28 deletions(-) diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c index d07e5abd07df..598f03ebb396 100644 --- a/fs/nfs/flexfilelayout/flexfilelayout.c +++ b/fs/nfs/flexfilelayout/flexfilelayout.c @@ -829,11 +829,14 @@ ff_layout_choose_best_ds_for_read(struct pnfs_layout_segment *lseg, { struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg); struct nfs4_pnfs_ds *ds; + bool fail_return = false; int idx; /* mirrors are sorted by efficiency */ for (idx = start_idx; idx < fls->mirror_array_cnt; idx++) { - ds = nfs4_ff_layout_prepare_ds(lseg, idx, false); + if (idx+1 == fls->mirror_array_cnt) + fail_return = true; + ds = nfs4_ff_layout_prepare_ds(lseg, idx, fail_return); if (ds) { *best_idx = idx; return ds; @@ -882,6 +885,7 @@ ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs4_pnfs_ds *ds; int ds_idx; +retry: /* Use full layout for now */ if (!pgio->pg_lseg) ff_layout_pg_get_read(pgio, req, false); @@ -894,10 +898,13 @@ ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio, ds = ff_layout_choose_best_ds_for_read(pgio->pg_lseg, 0, &ds_idx); if (!ds) { - if (ff_layout_no_fallback_to_mds(pgio->pg_lseg)) - goto out_pnfs; - else + if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg)) goto out_mds; + pnfs_put_lseg(pgio->pg_lseg); + pgio->pg_lseg = NULL; + /* Sleep for 1 second before retrying */ + ssleep(1); + goto retry; } mirror = FF_LAYOUT_COMP(pgio->pg_lseg, ds_idx); @@ -913,12 +920,6 @@ out_mds: pnfs_put_lseg(pgio->pg_lseg); pgio->pg_lseg = NULL; nfs_pageio_reset_read_mds(pgio); - return; - -out_pnfs: - pnfs_set_lo_fail(pgio->pg_lseg); - pnfs_put_lseg(pgio->pg_lseg); - pgio->pg_lseg = NULL; } static void @@ -932,6 +933,7 @@ ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio, int i; int status; +retry: if (!pgio->pg_lseg) { pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode, req->wb_context, @@ -963,10 +965,13 @@ ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio, for (i = 0; i < pgio->pg_mirror_count; i++) { ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, i, true); if (!ds) { - if (ff_layout_no_fallback_to_mds(pgio->pg_lseg)) - goto out_pnfs; - else + if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg)) goto out_mds; + pnfs_put_lseg(pgio->pg_lseg); + pgio->pg_lseg = NULL; + /* Sleep for 1 second before retrying */ + ssleep(1); + goto retry; } pgm = &pgio->pg_mirrors[i]; mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i); @@ -979,12 +984,6 @@ out_mds: pnfs_put_lseg(pgio->pg_lseg); pgio->pg_lseg = NULL; nfs_pageio_reset_write_mds(pgio); - return; - -out_pnfs: - pnfs_set_lo_fail(pgio->pg_lseg); - pnfs_put_lseg(pgio->pg_lseg); - pgio->pg_lseg = NULL; } static unsigned int diff --git a/fs/nfs/flexfilelayout/flexfilelayoutdev.c b/fs/nfs/flexfilelayout/flexfilelayoutdev.c index 2dd3ead08973..360b0ff2cd75 100644 --- a/fs/nfs/flexfilelayout/flexfilelayoutdev.c +++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c @@ -418,7 +418,7 @@ nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx, devid = &mirror->mirror_ds->id_node; if (ff_layout_test_devid_unavailable(devid)) - goto out; + goto out_fail; ds = mirror->mirror_ds->ds; /* matching smp_wmb() in _nfs4_pnfs_v3/4_ds_connect */ @@ -453,15 +453,16 @@ nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx, mirror->mirror_ds->ds_versions[0].rsize = max_payload; if (mirror->mirror_ds->ds_versions[0].wsize > max_payload) mirror->mirror_ds->ds_versions[0].wsize = max_payload; - } else { - ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout), - mirror, lseg->pls_range.offset, - lseg->pls_range.length, NFS4ERR_NXIO, - OP_ILLEGAL, GFP_NOIO); - if (fail_return || !ff_layout_has_available_ds(lseg)) - pnfs_error_mark_layout_for_return(ino, lseg); - ds = NULL; + goto out; } + ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout), + mirror, lseg->pls_range.offset, + lseg->pls_range.length, NFS4ERR_NXIO, + OP_ILLEGAL, GFP_NOIO); +out_fail: + if (fail_return || !ff_layout_has_available_ds(lseg)) + pnfs_error_mark_layout_for_return(ino, lseg); + ds = NULL; out: return ds; } -- 2.7.4