NFS: Add a boot parameter to disable 64 bit inode numbers
This boot parameter will allow legacy 32-bit applications which call stat()
to continue to function even if the NFSv3/v4 server uses 64-bit inode
numbers.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index cad1246..035c769 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -49,6 +49,11 @@
#define NFSDBG_FACILITY NFSDBG_VFS
+#define NFS_64_BIT_INODE_NUMBERS_ENABLED 1
+
+/* Default is to see 64-bit inode numbers */
+static int enable_ino64 = NFS_64_BIT_INODE_NUMBERS_ENABLED;
+
static void nfs_invalidate_inode(struct inode *);
static int nfs_update_inode(struct inode *, struct nfs_fattr *);
@@ -62,6 +67,25 @@
return nfs_fileid_to_ino_t(fattr->fileid);
}
+/**
+ * nfs_compat_user_ino64 - returns the user-visible inode number
+ * @fileid: 64-bit fileid
+ *
+ * This function returns a 32-bit inode number if the boot parameter
+ * nfs.enable_ino64 is zero.
+ */
+u64 nfs_compat_user_ino64(u64 fileid)
+{
+ int ino;
+
+ if (enable_ino64)
+ return fileid;
+ ino = fileid;
+ if (sizeof(ino) < sizeof(fileid))
+ ino ^= fileid >> (sizeof(fileid)-sizeof(ino)) * 8;
+ return ino;
+}
+
int nfs_write_inode(struct inode *inode, int sync)
{
int ret;
@@ -456,7 +480,7 @@
err = nfs_revalidate_inode(NFS_SERVER(inode), inode);
if (!err) {
generic_fillattr(inode, stat);
- stat->ino = NFS_FILEID(inode);
+ stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
}
return err;
}
@@ -1235,6 +1259,7 @@
/* Not quite true; I just maintain it */
MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
MODULE_LICENSE("GPL");
+module_param(enable_ino64, bool, 0644);
module_init(init_nfs_fs)
module_exit(exit_nfs_fs)