Commit 3c9e502b authored by Trond Myklebust's avatar Trond Myklebust
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NFS: Add a helper nfs_client_for_each_server()



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: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 58ac3e59
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+3 −1
Original line number Diff line number Diff line
@@ -417,7 +417,9 @@ 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);
+35 −0
Original line number Diff line number Diff line
@@ -176,6 +176,41 @@ 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
 */