The TEST_STATEID and FREE_STATEID operations can return
NFS4ERR_BAD_STATEID, NFS4ERR_OLD_STATEID, or NFS4ERR_DEADSESSION.
These error values should not be passed to nfs4_handle_exception(),
since that will recursively kick off state recovery, resulting in a
deadlock.
The reason to continue using nfs4_handle_exception() is to deal with
NFS4ERR_DELAY. [ Sidebar: It seems to me we are dealing with only
DELAY in enough places now that it might make sense to add a version
of nfs4_handle_exception() that handles only GRACE and DELAY) ].
Moreover, specifically when the TEST_STATEID operation returns
NFS4_OK, res.status can contain one of these errors.
_nfs41_test_stateid() replaces NFS4_OK with the value in res.status,
which is then returned to callers.
But res.status is not passed through nfs4_stat_to_errno(), and thus is
a positive NFS4ERR value. Currently callers are only interested in
!NFS4_OK, and nfs4_handle_exception() ignores positive values, so this
oversight hasn't bitten us so far.
Bryan agrees the original intent was to return res.status as a
negative NFS4ERR value to callers of nfs41_test_stateid(), as long as
no state ID recovery is attempted.
As a finishing touch, add appropriate documenting comments and some
debugging printk's. Documenting comments are added to record the
intent of the return value.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfs/nfs4proc.c | 51 ++++++++++++++++++++++++++++++++++++++++-----------
1 files changed, 40 insertions(+), 11 deletions(-)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 0d46fe4..4f1e824 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6384,22 +6384,36 @@ static int _nfs41_test_stateid(struct nfs_server *server, nfs4_stateid *stateid)
.rpc_resp = &res,
};
+ dprintk("NFS call test_stateid %p\n", stateid);
nfs41_init_sequence(&args.seq_args, &res.seq_res, 0);
status = nfs4_call_sync_sequence(server->client, server, &msg, &args.seq_args, &res.seq_res, 1);
-
- if (status == NFS_OK)
- return res.status;
- return status;
+ if (status != NFS_OK) {
+ dprintk("NFS reply test_stateid: failed, %d\n", status);
+ return status;
+ }
+ dprintk("NFS reply test_stateid: succeeded, %d\n", -res.status);
+ return -res.status;
}
+/**
+ * nfs41_test_stateid - perform a TEST_STATEID operation
+ *
+ * @server: NFS server that may know about "stateid"
+ * @stateid: state ID to test
+ *
+ * Returns NFS_OK if the server recognizes the state ID as valid.
+ * Otherwise a negative NFS4ERR value is returned if the operation
+ * failed or the state ID is not currently valid.
+ */
static int nfs41_test_stateid(struct nfs_server *server, nfs4_stateid *stateid)
{
struct nfs4_exception exception = { };
int err;
do {
- err = nfs4_handle_exception(server,
- _nfs41_test_stateid(server, stateid),
- &exception);
+ err = _nfs41_test_stateid(server, stateid);
+ if (err != -NFS4ERR_DELAY)
+ break;
+ nfs4_handle_exception(server, err, &exception);
} while (exception.retry);
return err;
}
@@ -6415,19 +6429,34 @@ static int _nfs4_free_stateid(struct nfs_server *server, nfs4_stateid *stateid)
.rpc_argp = &args,
.rpc_resp = &res,
};
+ int status;
+ dprintk("NFS call free_stateid %p\n", stateid);
nfs41_init_sequence(&args.seq_args, &res.seq_res, 0);
- return nfs4_call_sync_sequence(server->client, server, &msg, &args.seq_args, &res.seq_res, 1);
+ status = nfs4_call_sync_sequence(server->client, server, &msg,
+ &args.seq_args, &res.seq_res, 1);
+ dprintk("NFS reply free_stateid: %d\n", status);
+ return status;
}
+/**
+ * nfs41_free_stateid - perform a FREE_STATEID operation
+ *
+ * @server: NFS server that may know about "stateid"
+ * @stateid: state ID to release
+ *
+ * Returns NFS_OK if the server freed the state ID. Otherwise a
+ * negative NFS4ERR value is returned if the operation failed.
+ */
static int nfs41_free_stateid(struct nfs_server *server, nfs4_stateid *stateid)
{
struct nfs4_exception exception = { };
int err;
do {
- err = nfs4_handle_exception(server,
- _nfs4_free_stateid(server, stateid),
- &exception);
+ err = _nfs4_free_stateid(server, stateid);
+ if (err != -NFS4ERR_DELAY)
+ break;
+ nfs4_handle_exception(server, err, &exception);
} while (exception.retry);
return err;
}
--
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