| .. | .. |
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| 1 | +// SPDX-License-Identifier: GPL-2.0-or-later |
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| 1 | 2 | /* getroot.c: get the root dentry for an NFS mount |
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| 2 | 3 | * |
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| 3 | 4 | * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved. |
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| 4 | 5 | * Written by David Howells (dhowells@redhat.com) |
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| 5 | | - * |
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| 6 | | - * This program is free software; you can redistribute it and/or |
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| 7 | | - * modify it under the terms of the GNU General Public License |
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| 8 | | - * as published by the Free Software Foundation; either version |
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| 9 | | - * 2 of the License, or (at your option) any later version. |
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| 10 | 6 | */ |
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| 11 | 7 | |
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| 12 | 8 | #include <linux/module.h> |
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| .. | .. |
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| 68 | 64 | /* |
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| 69 | 65 | * get an NFS2/NFS3 root dentry from the root filehandle |
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| 70 | 66 | */ |
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| 71 | | -struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh, |
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| 72 | | - const char *devname) |
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| 67 | +int nfs_get_root(struct super_block *s, struct fs_context *fc) |
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| 73 | 68 | { |
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| 74 | | - struct nfs_server *server = NFS_SB(sb); |
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| 69 | + struct nfs_fs_context *ctx = nfs_fc2context(fc); |
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| 70 | + struct nfs_server *server = NFS_SB(s); |
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| 75 | 71 | struct nfs_fsinfo fsinfo; |
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| 76 | | - struct dentry *ret; |
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| 72 | + struct dentry *root; |
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| 77 | 73 | struct inode *inode; |
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| 78 | | - void *name = kstrdup(devname, GFP_KERNEL); |
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| 79 | | - int error; |
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| 74 | + char *name; |
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| 75 | + int error = -ENOMEM; |
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| 76 | + unsigned long kflags = 0, kflags_out = 0; |
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| 80 | 77 | |
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| 78 | + name = kstrdup(fc->source, GFP_KERNEL); |
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| 81 | 79 | if (!name) |
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| 82 | | - return ERR_PTR(-ENOMEM); |
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| 80 | + goto out; |
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| 83 | 81 | |
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| 84 | 82 | /* get the actual root for this mount */ |
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| 85 | 83 | fsinfo.fattr = nfs_alloc_fattr(); |
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| 86 | | - if (fsinfo.fattr == NULL) { |
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| 87 | | - kfree(name); |
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| 88 | | - return ERR_PTR(-ENOMEM); |
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| 89 | | - } |
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| 84 | + if (fsinfo.fattr == NULL) |
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| 85 | + goto out_name; |
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| 90 | 86 | |
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| 91 | | - error = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo); |
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| 87 | + fsinfo.fattr->label = nfs4_label_alloc(server, GFP_KERNEL); |
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| 88 | + if (IS_ERR(fsinfo.fattr->label)) |
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| 89 | + goto out_fattr; |
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| 90 | + error = server->nfs_client->rpc_ops->getroot(server, ctx->mntfh, &fsinfo); |
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| 92 | 91 | if (error < 0) { |
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| 93 | 92 | dprintk("nfs_get_root: getattr error = %d\n", -error); |
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| 94 | | - ret = ERR_PTR(error); |
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| 95 | | - goto out; |
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| 93 | + nfs_errorf(fc, "NFS: Couldn't getattr on root"); |
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| 94 | + goto out_label; |
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| 96 | 95 | } |
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| 97 | 96 | |
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| 98 | | - inode = nfs_fhget(sb, mntfh, fsinfo.fattr, NULL); |
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| 97 | + inode = nfs_fhget(s, ctx->mntfh, fsinfo.fattr, NULL); |
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| 99 | 98 | if (IS_ERR(inode)) { |
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| 100 | 99 | dprintk("nfs_get_root: get root inode failed\n"); |
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| 101 | | - ret = ERR_CAST(inode); |
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| 102 | | - goto out; |
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| 100 | + error = PTR_ERR(inode); |
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| 101 | + nfs_errorf(fc, "NFS: Couldn't get root inode"); |
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| 102 | + goto out_label; |
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| 103 | 103 | } |
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| 104 | 104 | |
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| 105 | | - error = nfs_superblock_set_dummy_root(sb, inode); |
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| 106 | | - if (error != 0) { |
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| 107 | | - ret = ERR_PTR(error); |
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| 108 | | - goto out; |
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| 109 | | - } |
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| 105 | + error = nfs_superblock_set_dummy_root(s, inode); |
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| 106 | + if (error != 0) |
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| 107 | + goto out_label; |
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| 110 | 108 | |
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| 111 | 109 | /* root dentries normally start off anonymous and get spliced in later |
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| 112 | 110 | * if the dentry tree reaches them; however if the dentry already |
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| 113 | 111 | * exists, we'll pick it up at this point and use it as the root |
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| 114 | 112 | */ |
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| 115 | | - ret = d_obtain_root(inode); |
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| 116 | | - if (IS_ERR(ret)) { |
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| 113 | + root = d_obtain_root(inode); |
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| 114 | + if (IS_ERR(root)) { |
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| 117 | 115 | dprintk("nfs_get_root: get root dentry failed\n"); |
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| 118 | | - goto out; |
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| 116 | + error = PTR_ERR(root); |
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| 117 | + nfs_errorf(fc, "NFS: Couldn't get root dentry"); |
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| 118 | + goto out_label; |
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| 119 | 119 | } |
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| 120 | 120 | |
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| 121 | | - security_d_instantiate(ret, inode); |
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| 122 | | - spin_lock(&ret->d_lock); |
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| 123 | | - if (IS_ROOT(ret) && !ret->d_fsdata && |
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| 124 | | - !(ret->d_flags & DCACHE_NFSFS_RENAMED)) { |
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| 125 | | - ret->d_fsdata = name; |
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| 121 | + security_d_instantiate(root, inode); |
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| 122 | + spin_lock(&root->d_lock); |
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| 123 | + if (IS_ROOT(root) && !root->d_fsdata && |
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| 124 | + !(root->d_flags & DCACHE_NFSFS_RENAMED)) { |
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| 125 | + root->d_fsdata = name; |
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| 126 | 126 | name = NULL; |
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| 127 | 127 | } |
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| 128 | | - spin_unlock(&ret->d_lock); |
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| 129 | | -out: |
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| 130 | | - kfree(name); |
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| 128 | + spin_unlock(&root->d_lock); |
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| 129 | + fc->root = root; |
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| 130 | + if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL) |
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| 131 | + kflags |= SECURITY_LSM_NATIVE_LABELS; |
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| 132 | + if (ctx->clone_data.sb) { |
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| 133 | + if (d_inode(fc->root)->i_fop != &nfs_dir_operations) { |
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| 134 | + error = -ESTALE; |
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| 135 | + goto error_splat_root; |
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| 136 | + } |
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| 137 | + /* clone lsm security options from the parent to the new sb */ |
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| 138 | + error = security_sb_clone_mnt_opts(ctx->clone_data.sb, |
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| 139 | + s, kflags, &kflags_out); |
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| 140 | + } else { |
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| 141 | + error = security_sb_set_mnt_opts(s, fc->security, |
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| 142 | + kflags, &kflags_out); |
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| 143 | + } |
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| 144 | + if (error) |
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| 145 | + goto error_splat_root; |
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| 146 | + if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL && |
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| 147 | + !(kflags_out & SECURITY_LSM_NATIVE_LABELS)) |
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| 148 | + NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL; |
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| 149 | + |
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| 150 | + nfs_setsecurity(inode, fsinfo.fattr, fsinfo.fattr->label); |
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| 151 | + error = 0; |
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| 152 | + |
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| 153 | +out_label: |
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| 154 | + nfs4_label_free(fsinfo.fattr->label); |
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| 155 | +out_fattr: |
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| 131 | 156 | nfs_free_fattr(fsinfo.fattr); |
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| 132 | | - return ret; |
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| 157 | +out_name: |
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| 158 | + kfree(name); |
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| 159 | +out: |
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| 160 | + return error; |
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| 161 | +error_splat_root: |
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| 162 | + dput(fc->root); |
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| 163 | + fc->root = NULL; |
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| 164 | + goto out_label; |
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| 133 | 165 | } |
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