From: Jeff Layton <jlayton@primarydata.com>
To: trond.myklebust@primarydata.com
Cc: linux-nfs@vger.kernel.org, mgorman@suse.de
Subject: [PATCH] nfs: fix RCU cl_xprt handling in nfs_swap_activate/deactivate
Date: Wed, 10 Sep 2014 09:03:55 -0400 [thread overview]
Message-ID: <1410354235-24315-1-git-send-email-jlayton@primarydata.com> (raw)
sparse says:
fs/nfs/file.c:543:60: warning: incorrect type in argument 1 (different address spaces)
fs/nfs/file.c:543:60: expected struct rpc_xprt *xprt
fs/nfs/file.c:543:60: got struct rpc_xprt [noderef] <asn:4>*cl_xprt
fs/nfs/file.c:548:53: warning: incorrect type in argument 1 (different address spaces)
fs/nfs/file.c:548:53: expected struct rpc_xprt *xprt
fs/nfs/file.c:548:53: got struct rpc_xprt [noderef] <asn:4>*cl_xprt
cl_xprt is RCU-managed, so we need to take care to dereference and use
it while holding the RCU read lock.
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
---
fs/nfs/file.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 524dd80d1898..fe7f6126a7d2 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -539,13 +539,25 @@ static int nfs_launder_page(struct page *page)
static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file,
sector_t *span)
{
+ int ret;
+ struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host);
+
*span = sis->pages;
- return xs_swapper(NFS_CLIENT(file->f_mapping->host)->cl_xprt, 1);
+
+ rcu_read_lock();
+ ret = xs_swapper(rcu_dereference(clnt->cl_xprt), 1);
+ rcu_read_unlock();
+
+ return ret;
}
static void nfs_swap_deactivate(struct file *file)
{
- xs_swapper(NFS_CLIENT(file->f_mapping->host)->cl_xprt, 0);
+ struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host);
+
+ rcu_read_lock();
+ xs_swapper(rcu_dereference(clnt->cl_xprt), 0);
+ rcu_read_unlock();
}
#endif
--
1.9.3
reply other threads:[~2014-09-10 13:04 UTC|newest]
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