NFSv4/pNFS: Do not fail I/O when we fail to allocate the pNFS layout

[ Upstream commit 3764a17e31d579cf9b4bd0a69894b577e8d75702 ]

Commit 587f03deb69b caused pnfs_update_layout() to stop returning ENOMEM
when the memory allocation fails, and hence causes it to fall back to
trying to do I/O through the MDS. There is no guarantee that this will
fare any better. If we're failing the pNFS layout allocation, then we
should just redirty the page and retry later.

Reported-by: Olga Kornievskaia <aglo@umich.edu>
Fixes: 587f03deb69b ("pnfs: refactor send_layoutget")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index b3b9eff5d57275a4be84a9e394c67ea581fa90aa..8c0803d9800843bc1864e24571af3d7e8faca810 100644 (file)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -2006,6 +2006,7 @@ lookup_again:
        lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
        if (lo == NULL) {
                spin_unlock(&ino->i_lock);
+               lseg = ERR_PTR(-ENOMEM);
                trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
                                 PNFS_UPDATE_LAYOUT_NOMEM);
                goto out;
@@ -2134,6 +2135,7 @@ lookup_again:
 
        lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &stateid, &arg, gfp_flags);
        if (!lgp) {
+               lseg = ERR_PTR(-ENOMEM);
                trace_pnfs_update_layout(ino, pos, count, iomode, lo, NULL,
                                         PNFS_UPDATE_LAYOUT_NOMEM);
                nfs_layoutget_end(lo);