pnfs: add a common GETDEVICELIST implementation

At a simple helper to issue a GETDEVICELIST operation and pre-load
the device id cache based on the result.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

2 files changed, 31 insertions, 0 deletions

diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index ce89ae364bb8..3eeca49d9ca2 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -277,6 +277,8 @@ bool nfs4_put_deviceid_node(struct nfs4_deviceid_node *);
 void nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node);
 bool nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node);
 void nfs4_deviceid_purge_client(const struct nfs_client *);
+int nfs4_deviceid_getdevicelist(struct nfs_server *server,
+                const struct nfs_fh *fh);
 
 static inline struct pnfs_layout_segment *
 pnfs_get_lseg(struct pnfs_layout_segment *lseg)
diff --git a/fs/nfs/pnfs_dev.c b/fs/nfs/pnfs_dev.c
index 791f8b3c4cff..82c2836fdb38 100644
--- a/fs/nfs/pnfs_dev.c
+++ b/fs/nfs/pnfs_dev.c
@@ -359,3 +359,32 @@ nfs4_deviceid_mark_client_invalid(struct nfs_client *clp)
         rcu_read_unlock();
 }
 
+int
+nfs4_deviceid_getdevicelist(struct nfs_server *server,
+                const struct nfs_fh *fh)
+{
+        struct pnfs_devicelist *dlist;
+        struct nfs4_deviceid_node *d;
+        int error = 0, i;
+
+        dlist = kzalloc(sizeof(struct pnfs_devicelist), GFP_NOFS);
+        if (!dlist)
+                return -ENOMEM;
+
+        while (!dlist->eof) {
+                error = nfs4_proc_getdevicelist(server, fh, dlist);
+                if (error)
+                        break;
+
+                for (i = 0; i < dlist->num_devs; i++) {
+                        d = nfs4_find_get_deviceid(server, &dlist->dev_id[i],
+                                        NULL, GFP_NOFS);
+                        if (d)
+                                nfs4_put_deviceid_node(d);
+                }
+        }
+
+        kfree(dlist);
+        return error;
+}
+EXPORT_SYMBOL_GPL(nfs4_deviceid_getdevicelist);