From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/fs/nfs/getroot.c | 133 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 133 insertions(+) create mode 100644 kernel/fs/nfs/getroot.c (limited to 'kernel/fs/nfs/getroot.c') diff --git a/kernel/fs/nfs/getroot.c b/kernel/fs/nfs/getroot.c new file mode 100644 index 000000000..a608ffd28 --- /dev/null +++ b/kernel/fs/nfs/getroot.c @@ -0,0 +1,133 @@ +/* getroot.c: get the root dentry for an NFS mount + * + * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "internal.h" + +#define NFSDBG_FACILITY NFSDBG_CLIENT + +/* + * Set the superblock root dentry. + * Note that this function frees the inode in case of error. + */ +static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *inode) +{ + /* The mntroot acts as the dummy root dentry for this superblock */ + if (sb->s_root == NULL) { + sb->s_root = d_make_root(inode); + if (sb->s_root == NULL) + return -ENOMEM; + ihold(inode); + /* + * Ensure that this dentry is invisible to d_find_alias(). + * Otherwise, it may be spliced into the tree by + * d_splice_alias if a parent directory from the same + * filesystem gets mounted at a later time. + * This again causes shrink_dcache_for_umount_subtree() to + * Oops, since the test for IS_ROOT() will fail. + */ + spin_lock(&d_inode(sb->s_root)->i_lock); + spin_lock(&sb->s_root->d_lock); + hlist_del_init(&sb->s_root->d_u.d_alias); + spin_unlock(&sb->s_root->d_lock); + spin_unlock(&d_inode(sb->s_root)->i_lock); + } + return 0; +} + +/* + * get an NFS2/NFS3 root dentry from the root filehandle + */ +struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh, + const char *devname) +{ + struct nfs_server *server = NFS_SB(sb); + struct nfs_fsinfo fsinfo; + struct dentry *ret; + struct inode *inode; + void *name = kstrdup(devname, GFP_KERNEL); + int error; + + if (!name) + return ERR_PTR(-ENOMEM); + + /* get the actual root for this mount */ + fsinfo.fattr = nfs_alloc_fattr(); + if (fsinfo.fattr == NULL) { + kfree(name); + return ERR_PTR(-ENOMEM); + } + + error = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo); + if (error < 0) { + dprintk("nfs_get_root: getattr error = %d\n", -error); + ret = ERR_PTR(error); + goto out; + } + + inode = nfs_fhget(sb, mntfh, fsinfo.fattr, NULL); + if (IS_ERR(inode)) { + dprintk("nfs_get_root: get root inode failed\n"); + ret = ERR_CAST(inode); + goto out; + } + + error = nfs_superblock_set_dummy_root(sb, inode); + if (error != 0) { + ret = ERR_PTR(error); + goto out; + } + + /* root dentries normally start off anonymous and get spliced in later + * if the dentry tree reaches them; however if the dentry already + * exists, we'll pick it up at this point and use it as the root + */ + ret = d_obtain_root(inode); + if (IS_ERR(ret)) { + dprintk("nfs_get_root: get root dentry failed\n"); + goto out; + } + + security_d_instantiate(ret, inode); + spin_lock(&ret->d_lock); + if (IS_ROOT(ret) && !ret->d_fsdata && + !(ret->d_flags & DCACHE_NFSFS_RENAMED)) { + ret->d_fsdata = name; + name = NULL; + } + spin_unlock(&ret->d_lock); +out: + kfree(name); + nfs_free_fattr(fsinfo.fattr); + return ret; +} -- cgit 1.2.3-korg