An NFSv4.2 COPY request can explicitly request a synchronous copy. If
that is not requested then the server is free to perform the copy
synchronously or asynchronously.
In the Linux implementation an async copy requires more resources than a
sync copy. If nfsd cannot allocate these resources, the best response
is to simply perform the copy (or the first 4MB of it) synchronously.
This choice may be debatable if the unavailable resource was due to
memory allocation failure - when memalloc fails it might be best to
simply give up as the server is clearly under load. However in the case
that policy prevents another kthread being created there is no benefit
and much cost is failing with NFS4ERR_DELAY. In that case it seems
reasonable to avoid that error in all circumstances.
So change the out_err case to retry as a sync copy.
Fixes: aadc3bbea163 ("NFSD: Limit the number of concurrent async COPY operations")
Signed-off-by: NeilBrown <neilb@xxxxxxx>
---
fs/nfsd/nfs4proc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index fea171ffed62..06e0d9153ca9 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1972,6 +1972,7 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
wake_up_process(async_copy->copy_task);
status = nfs_ok;
} else {
+ retry_sync:
status = nfsd4_do_copy(copy, copy->nf_src->nf_file,
copy->nf_dst->nf_file, true);
}
@@ -1990,8 +1991,7 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
}
if (async_copy)
cleanup_async_copy(async_copy);
- status = nfserr_jukebox;
- goto out;
+ goto retry_sync;
}
static struct nfsd4_copy *
base-commit: 26e6e693936986309c01e8bb80e318d63fda4a44
--
2.47.0
