9p: add 9P2000.L statfs operation

I made a V2 of this patch on top of my patches for VFS switches. The
change was adding v9fs_statfs pointer to v9fs_super_ops_dotl
instead of v9fs_super_ops.

statfs - get file system statistics

size[4] Tstatfs tag[2] fid[4]
size[4] Rstatfs tag[2] type[4] bsize[4] blocks[8] bfree[8] bavail[8]
                files[8] ffree[8] fsid[8] namelen[4]

The statfs message is used to request file system information returned
by the statfs(2) system call, which is used by df(1) to report file
system and disk space usage.

Signed-off-by: Jim Garlick <garlick@llnl.gov>
Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/net/9p/client.c b/net/9p/client.c
index e2d31467496..430a1c4a7c6 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1365,3 +1365,42 @@ error:
 	return err;
 }
 EXPORT_SYMBOL(p9_client_wstat);
+
+int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
+{
+	int err;
+	struct p9_req_t *req;
+	struct p9_client *clnt;
+
+	err = 0;
+	clnt = fid->clnt;
+
+	P9_DPRINTK(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
+
+	req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
+	if (IS_ERR(req)) {
+		err = PTR_ERR(req);
+		goto error;
+	}
+
+	err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
+		&sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
+		&sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
+	if (err) {
+		p9pdu_dump(1, req->rc);
+		p9_free_req(clnt, req);
+		goto error;
+	}
+
+	P9_DPRINTK(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
+		"blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
+		"fsid %llu namelen %ld\n",
+		fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
+		sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
+		sb->fsid, (long int)sb->namelen);
+
+	p9_free_req(clnt, req);
+error:
+	return err;
+}
+EXPORT_SYMBOL(p9_client_statfs);