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| author |   Yang Erkun <yangerkun@huawei.com> | 2024-12-25 14:59:06 +0800 |
|---|---|---|
| committer |   Chuck Lever <chuck.lever@oracle.com> | 2025-01-06 09:37:41 -0500 |
| commit | c224edca7af028828e2ad866b61d731b5e72b46d (patch) | |
| tree | 5e3da1a35a8ef7246ba146f7a04f0ba68e73b8ab | |
| parent | SUNRPC: introduce cache_check_rcu to help check in rcu context (diff) | |
| download | wireguard-linux-c224edca7af028828e2ad866b61d731b5e72b46d.tar.xz wireguard-linux-c224edca7af028828e2ad866b61d731b5e72b46d.zip | |
nfsd: no need get cache ref when protected by rcu
rcu_read_lock/rcu_read_unlock has already provide protection for the
pointer we will reference when we call e_show. Therefore, there is no
need to obtain a cache reference to help protect cache_head.
Additionally, the .put such as expkey_put/svc_export_put will invoke
dput, which can sleep and break rcu. Stop get cache reference to fix
them all.
Fixes: ae74136b4bb6 ("SUNRPC: Allow cache lookups to use RCU protection rather than the r/w spinlock")
Suggested-by: NeilBrown <neilb@suse.de>
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to '')
| -rw-r--r-- | fs/nfsd/export.c | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c index aa4712362b3b..c6168bccfb6c 100644 --- a/fs/nfsd/export.c +++ b/fs/nfsd/export.c @@ -1425,13 +1425,9 @@ static int e_show(struct seq_file *m, void *p) return 0; } - if (!cache_get_rcu(&exp->h)) + if (cache_check_rcu(cd, &exp->h, NULL)) return 0; - if (cache_check(cd, &exp->h, NULL)) - return 0; - - exp_put(exp); return svc_export_show(m, cd, cp); } |