NFS: Store the file system "fsid" value in the NFS super block.

This should enable us to detect if we are crossing a mountpoint in the
case where the server is exporting "nohide" mounts.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

5 files changed, 14 insertions, 5 deletions

diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index 3fab5b0cfc5..b81e7ed3c90 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -47,7 +47,6 @@
 #include <linux/workqueue.h>
 #include <linux/sunrpc/rpc_pipe_fs.h>
 
-#include <linux/nfs_fs_sb.h>
 #include <linux/nfs_fs.h>
 
 #include <linux/nfs_idmap.h>
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index fda2b496617..1a809f6f898 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -236,6 +236,7 @@ nfs_get_root(struct super_block *sb, struct nfs_fh *rootfh, struct nfs_fsinfo *f
 		return ERR_PTR(error);
 	}
 
+	server->fsid = fsinfo->fattr->fsid;
 	return nfs_fhget(sb, rootfh, fsinfo->fattr);
 }
 
@@ -1493,6 +1494,7 @@ out:
  */
 static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 {
+	struct nfs_server *server;
 	struct nfs_inode *nfsi = NFS_I(inode);
 	loff_t cur_isize, new_isize;
 	unsigned int	invalid = 0;
@@ -1511,6 +1513,12 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
 	if ((inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
 		goto out_changed;
 
+	server = NFS_SERVER(inode);
+	/* Update the fsid if and only if this is the root directory */
+	if (inode == inode->i_sb->s_root->d_inode
+			&& !nfs_fsid_equal(&server->fsid, &fattr->fsid))
+		server->fsid = fattr->fsid;
+
 	/*
 	 * Update the read time so we don't revalidate too often.
 	 */
diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index f0015fa876e..a7ed88f97a1 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -131,7 +131,8 @@ xdr_decode_fattr(u32 *p, struct nfs_fattr *fattr)
 	fattr->du.nfs2.blocksize = ntohl(*p++);
 	rdev = ntohl(*p++);
 	fattr->du.nfs2.blocks = ntohl(*p++);
-	fattr->fsid_u.nfs3 = ntohl(*p++);
+	fattr->fsid.major = ntohl(*p++);
+	fattr->fsid.minor = 0;
 	fattr->fileid = ntohl(*p++);
 	p = xdr_decode_time(p, &fattr->atime);
 	p = xdr_decode_time(p, &fattr->mtime);
diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index ec233619687..f70eee2cac0 100644
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -166,7 +166,8 @@ xdr_decode_fattr(u32 *p, struct nfs_fattr *fattr)
 	if (MAJOR(fattr->rdev) != major || MINOR(fattr->rdev) != minor)
 		fattr->rdev = 0;
 
-	p = xdr_decode_hyper(p, &fattr->fsid_u.nfs3);
+	p = xdr_decode_hyper(p, &fattr->fsid.major);
+	fattr->fsid.minor = 0;
 	p = xdr_decode_hyper(p, &fattr->fileid);
 	p = xdr_decode_time3(p, &fattr->atime);
 	p = xdr_decode_time3(p, &fattr->mtime);
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 7e9a840057f..0d579467594 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -2217,7 +2217,7 @@ static int decode_attr_symlink_support(struct xdr_stream *xdr, uint32_t *bitmap,
 	return 0;
 }
 
-static int decode_attr_fsid(struct xdr_stream *xdr, uint32_t *bitmap, struct nfs4_fsid *fsid)
+static int decode_attr_fsid(struct xdr_stream *xdr, uint32_t *bitmap, struct nfs_fsid *fsid)
 {
 	uint32_t *p;
 
@@ -2863,7 +2863,7 @@ static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr, cons
 		goto xdr_error;
 	if ((status = decode_attr_size(xdr, bitmap, &fattr->size)) != 0)
 		goto xdr_error;
-	if ((status = decode_attr_fsid(xdr, bitmap, &fattr->fsid_u.nfs4)) != 0)
+	if ((status = decode_attr_fsid(xdr, bitmap, &fattr->fsid)) != 0)
 		goto xdr_error;
 	if ((status = decode_attr_fileid(xdr, bitmap, &fattr->fileid)) != 0)
 		goto xdr_error;