diff options
| author | Jeff Layton <jlayton@poochiereds.net> | 2015-06-03 16:14:25 -0400 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2015-06-10 18:26:14 -0400 |
| commit | 3c87ef6efb40f0e339d705c194b2224f854ec38e (patch) | |
| tree | 2878ea261637cf6c85ab69b9cbde70a036b1e3a2 /net/sunrpc/xprtsock.c | |
| parent | 0d2a970d0ae55086520e1e58e572a7acd519429c (diff) | |
| download | linux-3c87ef6efb40f0e339d705c194b2224f854ec38e.tar.gz linux-3c87ef6efb40f0e339d705c194b2224f854ec38e.tar.bz2 linux-3c87ef6efb40f0e339d705c194b2224f854ec38e.zip | |
sunrpc: keep a count of swapfiles associated with the rpc_clnt
Jerome reported seeing a warning pop when working with a swapfile on
NFS. The nfs_swap_activate can end up calling sk_set_memalloc while
holding the rcu_read_lock and that function can sleep.
To fix that, we need to take a reference to the xprt while holding the
rcu_read_lock, set the socket up for swapping and then drop that
reference. But, xprt_put is not exported and having NFS deal with the
underlying xprt is a bit of layering violation anyway.
Fix this by adding a set of activate/deactivate functions that take a
rpc_clnt pointer instead of an rpc_xprt, and have nfs_swap_activate and
nfs_swap_deactivate call those.
Also, add a per-rpc_clnt atomic counter to keep track of the number of
active swapfiles associated with it. When the counter does a 0->1
transition, we enable swapping on the xprt, when we do a 1->0 transition
we disable swapping on it.
This also allows us to be a bit more selective with the RPC_TASK_SWAPPER
flag. If non-swapper and swapper clnts are sharing a xprt, then we only
need to flag the tasks from the swapper clnt with that flag.
Acked-by: Mel Gorman <mgorman@suse.de>
Reported-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'net/sunrpc/xprtsock.c')
| -rw-r--r-- | net/sunrpc/xprtsock.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index b142feef0cf4..f344c0f8974c 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1955,7 +1955,7 @@ static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task) msleep_interruptible(15000); } -#ifdef CONFIG_SUNRPC_SWAP +#if IS_ENABLED(CONFIG_SUNRPC_SWAP) static void xs_set_memalloc(struct rpc_xprt *xprt) { struct sock_xprt *transport = container_of(xprt, struct sock_xprt, @@ -1987,7 +1987,6 @@ int xs_swapper(struct rpc_xprt *xprt, int enable) return err; } -EXPORT_SYMBOL_GPL(xs_swapper); #else static void xs_set_memalloc(struct rpc_xprt *xprt) { |