diff options
Diffstat (limited to 'fs/ecryptfs/inode.c')
-rw-r--r-- | fs/ecryptfs/inode.c | 283 |
1 files changed, 175 insertions, 108 deletions
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 4d4cc6a90cd5..7349ade17de6 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -51,6 +51,97 @@ static void unlock_dir(struct dentry *dir) dput(dir); } +static int ecryptfs_inode_test(struct inode *inode, void *lower_inode) +{ + if (ecryptfs_inode_to_lower(inode) == (struct inode *)lower_inode) + return 1; + return 0; +} + +static int ecryptfs_inode_set(struct inode *inode, void *opaque) +{ + struct inode *lower_inode = opaque; + + ecryptfs_set_inode_lower(inode, lower_inode); + fsstack_copy_attr_all(inode, lower_inode); + /* i_size will be overwritten for encrypted regular files */ + fsstack_copy_inode_size(inode, lower_inode); + inode->i_ino = lower_inode->i_ino; + inode->i_version++; + inode->i_mapping->a_ops = &ecryptfs_aops; + + if (S_ISLNK(inode->i_mode)) + inode->i_op = &ecryptfs_symlink_iops; + else if (S_ISDIR(inode->i_mode)) + inode->i_op = &ecryptfs_dir_iops; + else + inode->i_op = &ecryptfs_main_iops; + + if (S_ISDIR(inode->i_mode)) + inode->i_fop = &ecryptfs_dir_fops; + else if (special_file(inode->i_mode)) + init_special_inode(inode, inode->i_mode, inode->i_rdev); + else + inode->i_fop = &ecryptfs_main_fops; + + return 0; +} + +static struct inode *__ecryptfs_get_inode(struct inode *lower_inode, + struct super_block *sb) +{ + struct inode *inode; + + if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) + return ERR_PTR(-EXDEV); + if (!igrab(lower_inode)) + return ERR_PTR(-ESTALE); + inode = iget5_locked(sb, (unsigned long)lower_inode, + ecryptfs_inode_test, ecryptfs_inode_set, + lower_inode); + if (!inode) { + iput(lower_inode); + return ERR_PTR(-EACCES); + } + if (!(inode->i_state & I_NEW)) + iput(lower_inode); + + return inode; +} + +struct inode *ecryptfs_get_inode(struct inode *lower_inode, + struct super_block *sb) +{ + struct inode *inode = __ecryptfs_get_inode(lower_inode, sb); + + if (!IS_ERR(inode) && (inode->i_state & I_NEW)) + unlock_new_inode(inode); + + return inode; +} + +/** + * ecryptfs_interpose + * @lower_dentry: Existing dentry in the lower filesystem + * @dentry: ecryptfs' dentry + * @sb: ecryptfs's super_block + * + * Interposes upper and lower dentries. + * + * Returns zero on success; non-zero otherwise + */ +static int ecryptfs_interpose(struct dentry *lower_dentry, + struct dentry *dentry, struct super_block *sb) +{ + struct inode *inode = ecryptfs_get_inode(lower_dentry->d_inode, sb); + + if (IS_ERR(inode)) + return PTR_ERR(inode); + d_instantiate(dentry, inode); + + return 0; +} + /** * ecryptfs_create_underlying_file * @lower_dir_inode: inode of the parent in the lower fs of the new file @@ -129,7 +220,7 @@ ecryptfs_do_create(struct inode *directory_inode, goto out_lock; } rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry, - directory_inode->i_sb, 0); + directory_inode->i_sb); if (rc) { ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n"); goto out_lock; @@ -168,7 +259,8 @@ static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry) "context; rc = [%d]\n", rc); goto out; } - rc = ecryptfs_get_lower_file(ecryptfs_dentry); + rc = ecryptfs_get_lower_file(ecryptfs_dentry, + ecryptfs_dentry->d_inode); if (rc) { printk(KERN_ERR "%s: Error attempting to initialize " "the lower file for the dentry with name " @@ -215,102 +307,90 @@ out: return rc; } +static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode) +{ + struct ecryptfs_crypt_stat *crypt_stat; + int rc; + + rc = ecryptfs_get_lower_file(dentry, inode); + if (rc) { + printk(KERN_ERR "%s: Error attempting to initialize " + "the lower file for the dentry with name " + "[%s]; rc = [%d]\n", __func__, + dentry->d_name.name, rc); + return rc; + } + + crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; + /* TODO: lock for crypt_stat comparison */ + if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) + ecryptfs_set_default_sizes(crypt_stat); + + rc = ecryptfs_read_and_validate_header_region(inode); + ecryptfs_put_lower_file(inode); + if (rc) { + rc = ecryptfs_read_and_validate_xattr_region(dentry, inode); + if (!rc) + crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; + } + + /* Must return 0 to allow non-eCryptfs files to be looked up, too */ + return 0; +} + /** - * ecryptfs_lookup_and_interpose_lower - Perform a lookup + * ecryptfs_lookup_interpose - Dentry interposition for a lookup */ -int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, - struct dentry *lower_dentry, - struct inode *ecryptfs_dir_inode) +static int ecryptfs_lookup_interpose(struct dentry *dentry, + struct dentry *lower_dentry, + struct inode *dir_inode) { - struct dentry *lower_dir_dentry; + struct inode *inode, *lower_inode = lower_dentry->d_inode; + struct ecryptfs_dentry_info *dentry_info; struct vfsmount *lower_mnt; - struct inode *lower_inode; - struct ecryptfs_crypt_stat *crypt_stat; - char *page_virt = NULL; - int put_lower = 0, rc = 0; - - lower_dir_dentry = lower_dentry->d_parent; - lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt( - ecryptfs_dentry->d_parent)); - lower_inode = lower_dentry->d_inode; - fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode); + int rc = 0; + + lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent)); + fsstack_copy_attr_atime(dir_inode, lower_dentry->d_parent->d_inode); BUG_ON(!lower_dentry->d_count); - ecryptfs_set_dentry_private(ecryptfs_dentry, - kmem_cache_alloc(ecryptfs_dentry_info_cache, - GFP_KERNEL)); - if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) { - rc = -ENOMEM; + + dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL); + ecryptfs_set_dentry_private(dentry, dentry_info); + if (!dentry_info) { printk(KERN_ERR "%s: Out of memory whilst attempting " "to allocate ecryptfs_dentry_info struct\n", __func__); - goto out_put; + dput(lower_dentry); + mntput(lower_mnt); + d_drop(dentry); + return -ENOMEM; } - ecryptfs_set_dentry_lower(ecryptfs_dentry, lower_dentry); - ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry, lower_mnt); + ecryptfs_set_dentry_lower(dentry, lower_dentry); + ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt); + if (!lower_dentry->d_inode) { /* We want to add because we couldn't find in lower */ - d_add(ecryptfs_dentry, NULL); - goto out; + d_add(dentry, NULL); + return 0; } - rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry, - ecryptfs_dir_inode->i_sb, - ECRYPTFS_INTERPOSE_FLAG_D_ADD); - if (rc) { - printk(KERN_ERR "%s: Error interposing; rc = [%d]\n", - __func__, rc); - goto out; + inode = __ecryptfs_get_inode(lower_inode, dir_inode->i_sb); + if (IS_ERR(inode)) { + printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n", + __func__, PTR_ERR(inode)); + return PTR_ERR(inode); } - if (S_ISDIR(lower_inode->i_mode)) - goto out; - if (S_ISLNK(lower_inode->i_mode)) - goto out; - if (special_file(lower_inode->i_mode)) - goto out; - /* Released in this function */ - page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER); - if (!page_virt) { - printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n", - __func__); - rc = -ENOMEM; - goto out; - } - rc = ecryptfs_get_lower_file(ecryptfs_dentry); - if (rc) { - printk(KERN_ERR "%s: Error attempting to initialize " - "the lower file for the dentry with name " - "[%s]; rc = [%d]\n", __func__, - ecryptfs_dentry->d_name.name, rc); - goto out_free_kmem; - } - put_lower = 1; - crypt_stat = &ecryptfs_inode_to_private( - ecryptfs_dentry->d_inode)->crypt_stat; - /* TODO: lock for crypt_stat comparison */ - if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) - ecryptfs_set_default_sizes(crypt_stat); - rc = ecryptfs_read_and_validate_header_region(page_virt, - ecryptfs_dentry->d_inode); - if (rc) { - memset(page_virt, 0, PAGE_CACHE_SIZE); - rc = ecryptfs_read_and_validate_xattr_region(page_virt, - ecryptfs_dentry); + if (S_ISREG(inode->i_mode)) { + rc = ecryptfs_i_size_read(dentry, inode); if (rc) { - rc = 0; - goto out_free_kmem; + make_bad_inode(inode); + return rc; } - crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; } - ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode); -out_free_kmem: - kmem_cache_free(ecryptfs_header_cache_2, page_virt); - goto out; -out_put: - dput(lower_dentry); - mntput(lower_mnt); - d_drop(ecryptfs_dentry); -out: - if (put_lower) - ecryptfs_put_lower_file(ecryptfs_dentry->d_inode); + + if (inode->i_state & I_NEW) + unlock_new_inode(inode); + d_add(dentry, inode); + return rc; } @@ -353,12 +433,12 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode, goto out_d_drop; } if (lower_dentry->d_inode) - goto lookup_and_interpose; + goto interpose; mount_crypt_stat = &ecryptfs_superblock_to_private( ecryptfs_dentry->d_sb)->mount_crypt_stat; if (!(mount_crypt_stat && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES))) - goto lookup_and_interpose; + goto interpose; dput(lower_dentry); rc = ecryptfs_encrypt_and_encode_filename( &encrypted_and_encoded_name, &encrypted_and_encoded_name_size, @@ -381,9 +461,9 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode, encrypted_and_encoded_name); goto out_d_drop; } -lookup_and_interpose: - rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry, - ecryptfs_dir_inode); +interpose: + rc = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry, + ecryptfs_dir_inode); goto out; out_d_drop: d_drop(ecryptfs_dentry); @@ -411,7 +491,7 @@ static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir, lower_new_dentry); if (rc || !lower_new_dentry->d_inode) goto out_lock; - rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0); + rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb); if (rc) goto out_lock; fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); @@ -478,7 +558,7 @@ static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry, kfree(encoded_symname); if (rc || !lower_dentry->d_inode) goto out_lock; - rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0); + rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb); if (rc) goto out_lock; fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); @@ -502,7 +582,7 @@ static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode); if (rc || !lower_dentry->d_inode) goto out; - rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0); + rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb); if (rc) goto out; fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); @@ -527,6 +607,8 @@ static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry) dget(lower_dentry); rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry); dput(lower_dentry); + if (!rc && dentry->d_inode) + clear_nlink(dentry->d_inode); fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); dir->i_nlink = lower_dir_dentry->d_inode->i_nlink; unlock_dir(lower_dir_dentry); @@ -548,7 +630,7 @@ ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev); if (rc || !lower_dentry->d_inode) goto out; - rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0); + rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb); if (rc) goto out; fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); @@ -748,7 +830,7 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia, lower_ia->ia_valid &= ~ATTR_SIZE; return 0; } - rc = ecryptfs_get_lower_file(dentry); + rc = ecryptfs_get_lower_file(dentry, inode); if (rc) return rc; crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat; @@ -904,7 +986,7 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) mount_crypt_stat = &ecryptfs_superblock_to_private( dentry->d_sb)->mount_crypt_stat; - rc = ecryptfs_get_lower_file(dentry); + rc = ecryptfs_get_lower_file(dentry, inode); if (rc) { mutex_unlock(&crypt_stat->cs_mutex); goto out; @@ -1077,21 +1159,6 @@ out: return rc; } -int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode) -{ - if ((ecryptfs_inode_to_lower(inode) - == (struct inode *)candidate_lower_inode)) - return 1; - else - return 0; -} - -int ecryptfs_inode_set(struct inode *inode, void *lower_inode) -{ - ecryptfs_init_inode(inode, (struct inode *)lower_inode); - return 0; -} - const struct inode_operations ecryptfs_symlink_iops = { .readlink = ecryptfs_readlink, .follow_link = ecryptfs_follow_link, |