diff options
| author | NeilBrown <neilb@suse.de> | 2023-02-08 15:45:38 +1100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-10 09:39:30 +0100 |
| commit | 91758289faad6bde52710b2114dcb3f658f9a50e (patch) | |
| tree | 2021867a903a3613f779bc9e5b3fea4ff1ab4666 /net/sunrpc | |
| parent | c78cfb19c9a2f413305801167e5cb66042b05887 (diff) | |
NFS: fix disabling of swap
[ Upstream commit 5bab56fff53ce161ed859d9559a10361d4f79578 ]
When swap is activated to a file on an NFSv4 mount we arrange that the
state manager thread is always present as starting a new thread requires
memory allocations that might block waiting for swap.
Unfortunately the code for allowing the state manager thread to exit when
swap is disabled was not tested properly and does not work.
This can be seen by examining /proc/fs/nfsfs/servers after disabling swap
and unmounting the filesystem. The servers file will still list one
entry. Also a "ps" listing will show the state manager thread is still
present.
There are two problems.
1/ rpc_clnt_swap_deactivate() doesn't walk up the ->cl_parent list to
find the primary client on which the state manager runs.
2/ The thread is not woken up properly and it immediately goes back to
sleep without checking whether it is really needed. Using
nfs4_schedule_state_manager() ensures a proper wake-up.
Reported-by: Olga Kornievskaia <aglo@umich.edu>
Fixes: 4dc73c679114 ("NFSv4: keep state manager thread active if swap is enabled")
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/sunrpc')
| -rw-r--r-- | net/sunrpc/clnt.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 6622dc1fa8f2..ad3e9a40b061 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -3138,6 +3138,8 @@ rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt, void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt) { + while (clnt != clnt->cl_parent) + clnt = clnt->cl_parent; if (atomic_dec_if_positive(&clnt->cl_swapper) == 0) rpc_clnt_iterate_for_each_xprt(clnt, rpc_clnt_swap_deactivate_callback, NULL); |