5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
[ Upstream commit 3c9e502b59fbd243cfac7cc6c875e432d285102a ]
Add a helper nfs_client_for_each_server() to iterate through all the
filesystems that are attached to a struct nfs_client, and apply
a function to all the active ones.
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Stable-dep-of: ed1cc05aa1f7 ("NFSv4: Fix a nfs4_state_manager() race")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/nfs/internal.h | 4 +++-
fs/nfs/super.c | 35 +++++++++++++++++++++++++++++++++++
2 files changed, 38 insertions(+), 1 deletion(-)
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index a4dc182e8989b..fcd35c98a9377 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -411,7 +411,9 @@ extern int __init register_nfs_fs(void);
extern void __exit unregister_nfs_fs(void);
extern bool nfs_sb_active(struct super_block *sb);
extern void nfs_sb_deactive(struct super_block *sb);
-
+extern int nfs_client_for_each_server(struct nfs_client *clp,
+ int (*fn)(struct nfs_server *, void *),
+ void *data);
/* io.c */
extern void nfs_start_io_read(struct inode *inode);
extern void nfs_end_io_read(struct inode *inode);
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index ecc7277b3eda4..1d3b681a6b279 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -436,6 +436,41 @@ void nfs_sb_deactive(struct super_block *sb)
}
EXPORT_SYMBOL_GPL(nfs_sb_deactive);
+static int __nfs_list_for_each_server(struct list_head *head,
+ int (*fn)(struct nfs_server *, void *),
+ void *data)
+{
+ struct nfs_server *server, *last = NULL;
+ int ret = 0;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(server, head, client_link) {
+ if (!nfs_sb_active(server->super))
+ continue;
+ rcu_read_unlock();
+ if (last)
+ nfs_sb_deactive(last->super);
+ last = server;
+ ret = fn(server, data);
+ if (ret)
+ goto out;
+ rcu_read_lock();
+ }
+ rcu_read_unlock();
+out:
+ if (last)
+ nfs_sb_deactive(last->super);
+ return ret;
+}
+
+int nfs_client_for_each_server(struct nfs_client *clp,
+ int (*fn)(struct nfs_server *, void *),
+ void *data)
+{
+ return __nfs_list_for_each_server(&clp->cl_superblocks, fn, data);
+}
+EXPORT_SYMBOL_GPL(nfs_client_for_each_server);
+
/*
* Deliver file system statistics to userspace
*/
--
2.40.1
