sanitize ecryptfs ->mount()
kill ecryptfs_read_super(), reorder code allowing to use normal d_alloc_root() instead of opencoding it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
parent
d61dcce297
commit
66cb76666d
2 changed files with 70 additions and 90 deletions
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@ -441,7 +441,6 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
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struct qstr lower_name;
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int rc = 0;
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d_set_d_op(ecryptfs_dentry, &ecryptfs_dops);
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if ((ecryptfs_dentry->d_name.len == 1
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&& !strcmp(ecryptfs_dentry->d_name.name, "."))
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|| (ecryptfs_dentry->d_name.len == 2
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@ -141,21 +141,9 @@ int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
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return rc;
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}
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/**
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* ecryptfs_interpose
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* @lower_dentry: Existing dentry in the lower filesystem
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* @dentry: ecryptfs' dentry
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* @sb: ecryptfs's super_block
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* @flags: flags to govern behavior of interpose procedure
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*
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* Interposes upper and lower dentries.
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*
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* Returns zero on success; non-zero otherwise
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*/
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int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
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struct super_block *sb, u32 flags)
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static inode *ecryptfs_get_inode(struct inode *lower_inode,
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struct super_block *sb)
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{
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struct inode *lower_inode;
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struct inode *inode;
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int rc = 0;
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@ -189,17 +177,38 @@ int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
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if (special_file(lower_inode->i_mode))
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init_special_inode(inode, lower_inode->i_mode,
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lower_inode->i_rdev);
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d_set_d_op(dentry, &ecryptfs_dops);
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fsstack_copy_attr_all(inode, lower_inode);
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/* This size will be overwritten for real files w/ headers and
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* other metadata */
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fsstack_copy_inode_size(inode, lower_inode);
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return inode;
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out:
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return ERR_PTR(rc);
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}
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/**
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* ecryptfs_interpose
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* @lower_dentry: Existing dentry in the lower filesystem
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* @dentry: ecryptfs' dentry
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* @sb: ecryptfs's super_block
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* @flags: flags to govern behavior of interpose procedure
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*
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* Interposes upper and lower dentries.
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*
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* Returns zero on success; non-zero otherwise
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*/
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int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
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struct super_block *sb, u32 flags)
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{
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struct inode *lower_inode = lower_dentry->d_inode;
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struct inode *inode = ecryptfs_get_inode(lower_inode, sb);
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if (IS_ERR(inode)
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return PTR_ERR(inode);
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if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
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d_add(dentry, inode);
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else
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d_instantiate(dentry, inode);
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out:
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return rc;
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return 0;
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}
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enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
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@ -491,60 +500,12 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options)
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struct kmem_cache *ecryptfs_sb_info_cache;
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static struct file_system_type ecryptfs_fs_type;
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/**
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* ecryptfs_read_super
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* @sb: The ecryptfs super block
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* @dev_name: The path to mount over
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*
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* Read the super block of the lower filesystem, and use
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* ecryptfs_interpose to create our initial inode and super block
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* struct.
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*/
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static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
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{
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struct path path;
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int rc;
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rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
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if (rc) {
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ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
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goto out;
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}
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if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
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rc = -EINVAL;
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printk(KERN_ERR "Mount on filesystem of type "
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"eCryptfs explicitly disallowed due to "
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"known incompatibilities\n");
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goto out_free;
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}
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ecryptfs_set_superblock_lower(sb, path.dentry->d_sb);
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sb->s_maxbytes = path.dentry->d_sb->s_maxbytes;
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sb->s_blocksize = path.dentry->d_sb->s_blocksize;
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ecryptfs_set_dentry_lower(sb->s_root, path.dentry);
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ecryptfs_set_dentry_lower_mnt(sb->s_root, path.mnt);
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rc = ecryptfs_interpose(path.dentry, sb->s_root, sb, 0);
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if (rc)
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goto out_free;
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rc = 0;
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goto out;
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out_free:
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path_put(&path);
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out:
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return rc;
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}
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/**
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* ecryptfs_get_sb
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* @fs_type
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* @flags
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* @dev_name: The path to mount over
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* @raw_data: The options passed into the kernel
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*
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* The whole ecryptfs_get_sb process is broken into 3 functions:
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* ecryptfs_parse_options(): handle options passed to ecryptfs, if any
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* ecryptfs_read_super(): this accesses the lower filesystem and uses
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* ecryptfs_interpose to perform most of the linking
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* ecryptfs_interpose(): links the lower filesystem into ecryptfs (inode.c)
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*/
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static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags,
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const char *dev_name, void *raw_data)
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@ -553,6 +514,8 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
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struct ecryptfs_sb_info *sbi;
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struct ecryptfs_dentry_info *root_info;
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const char *err = "Getting sb failed";
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struct inode *inode;
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struct path path;
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int rc;
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sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
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@ -575,10 +538,8 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
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s->s_flags = flags;
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rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY);
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if (rc) {
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deactivate_locked_super(s);
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goto out;
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}
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if (rc)
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goto out1;
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ecryptfs_set_superblock_private(s, sbi);
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s->s_bdi = &sbi->bdi;
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@ -586,34 +547,54 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
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/* ->kill_sb() will take care of sbi after that point */
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sbi = NULL;
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s->s_op = &ecryptfs_sops;
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s->s_d_op = &ecryptfs_dops;
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err = "Reading sb failed";
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rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
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if (rc) {
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ecryptfs_printk(KERN_WARNING, "kern_path() failed\n");
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goto out1;
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}
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if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
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rc = -EINVAL;
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printk(KERN_ERR "Mount on filesystem of type "
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"eCryptfs explicitly disallowed due to "
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"known incompatibilities\n");
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goto out_free;
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}
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ecryptfs_set_superblock_lower(s, path.dentry->d_sb);
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s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
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s->s_blocksize = path.dentry->d_sb->s_blocksize;
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inode = ecryptfs_get_inode(path.dentry->d_inode, s);
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rc = PTR_ERR(inode);
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if (IS_ERR(inode))
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goto out_free;
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s->s_root = d_alloc_root(inode);
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if (!s->s_root) {
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iput(inode);
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rc = -ENOMEM;
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goto out_free;
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}
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rc = -ENOMEM;
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s->s_root = d_alloc(NULL, &(const struct qstr) {
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.hash = 0,.name = "/",.len = 1});
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if (!s->s_root) {
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deactivate_locked_super(s);
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goto out;
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}
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d_set_d_op(s->s_root, &ecryptfs_dops);
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s->s_root->d_sb = s;
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s->s_root->d_parent = s->s_root;
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root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
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if (!root_info) {
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deactivate_locked_super(s);
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goto out;
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}
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if (!root_info)
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goto out_free;
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/* ->kill_sb() will take care of root_info */
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ecryptfs_set_dentry_private(s->s_root, root_info);
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ecryptfs_set_dentry_lower(s->s_root, path.dentry);
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ecryptfs_set_dentry_lower_mnt(s->s_root, path.mnt);
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s->s_flags |= MS_ACTIVE;
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rc = ecryptfs_read_super(s, dev_name);
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if (rc) {
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deactivate_locked_super(s);
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err = "Reading sb failed";
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goto out;
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}
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return dget(s->s_root);
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out_free:
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path_put(&path);
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out1:
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deactivate_locked_super(s);
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out:
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if (sbi) {
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ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
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