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 0f1c158594188c9916550d75ee5fa140788bd610..a7d638bfb46b9ecdf6f41937a5d26d7968b28023 100644 (file)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1897,6 +1897,7 @@ 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;
@@ -2024,6 +2025,7 @@ 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);