コード例 #1
0
ファイル: symlink.c プロジェクト: SantoshShilimkar/linux
static const char *ext4_encrypted_get_link(struct dentry *dentry,
					   struct inode *inode,
					   struct delayed_call *done)
{
	struct page *cpage = NULL;
	char *caddr, *paddr = NULL;
	struct fscrypt_str cstr, pstr;
	struct fscrypt_symlink_data *sd;
	int res;
	u32 max_size = inode->i_sb->s_blocksize;

	if (!dentry)
		return ERR_PTR(-ECHILD);

	res = fscrypt_get_encryption_info(inode);
	if (res)
		return ERR_PTR(res);

	if (ext4_inode_is_fast_symlink(inode)) {
		caddr = (char *) EXT4_I(inode)->i_data;
		max_size = sizeof(EXT4_I(inode)->i_data);
	} else {
		cpage = read_mapping_page(inode->i_mapping, 0, NULL);
		if (IS_ERR(cpage))
			return ERR_CAST(cpage);
		caddr = page_address(cpage);
	}

	/* Symlink is encrypted */
	sd = (struct fscrypt_symlink_data *)caddr;
	cstr.name = sd->encrypted_path;
	cstr.len  = le16_to_cpu(sd->len);
	if ((cstr.len + sizeof(struct fscrypt_symlink_data) - 1) > max_size) {
		/* Symlink data on the disk is corrupted */
		res = -EFSCORRUPTED;
		goto errout;
	}

	res = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr);
	if (res)
		goto errout;
	paddr = pstr.name;

	res = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr);
	if (res)
		goto errout;

	/* Null-terminate the name */
	paddr[pstr.len] = '\0';
	if (cpage)
		put_page(cpage);
	set_delayed_call(done, kfree_link, paddr);
	return paddr;
errout:
	if (cpage)
		put_page(cpage);
	kfree(paddr);
	return ERR_PTR(res);
}
コード例 #2
0
ファイル: hooks.c プロジェクト: AlexShiLucky/linux
/**
 * fscrypt_get_symlink - get the target of an encrypted symlink
 * @inode: the symlink inode
 * @caddr: the on-disk contents of the symlink
 * @max_size: size of @caddr buffer
 * @done: if successful, will be set up to free the returned target
 *
 * If the symlink's encryption key is available, we decrypt its target.
 * Otherwise, we encode its target for presentation.
 *
 * This may sleep, so the filesystem must have dropped out of RCU mode already.
 *
 * Return: the presentable symlink target or an ERR_PTR()
 */
const char *fscrypt_get_symlink(struct inode *inode, const void *caddr,
				unsigned int max_size,
				struct delayed_call *done)
{
	const struct fscrypt_symlink_data *sd;
	struct fscrypt_str cstr, pstr;
	int err;

	/* This is for encrypted symlinks only */
	if (WARN_ON(!IS_ENCRYPTED(inode)))
		return ERR_PTR(-EINVAL);

	/*
	 * Try to set up the symlink's encryption key, but we can continue
	 * regardless of whether the key is available or not.
	 */
	err = fscrypt_get_encryption_info(inode);
	if (err)
		return ERR_PTR(err);

	/*
	 * For historical reasons, encrypted symlink targets are prefixed with
	 * the ciphertext length, even though this is redundant with i_size.
	 */

	if (max_size < sizeof(*sd))
		return ERR_PTR(-EUCLEAN);
	sd = caddr;
	cstr.name = (unsigned char *)sd->encrypted_path;
	cstr.len = le16_to_cpu(sd->len);

	if (cstr.len == 0)
		return ERR_PTR(-EUCLEAN);

	if (cstr.len + sizeof(*sd) - 1 > max_size)
		return ERR_PTR(-EUCLEAN);

	err = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr);
	if (err)
		return ERR_PTR(err);

	err = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr);
	if (err)
		goto err_kfree;

	err = -EUCLEAN;
	if (pstr.name[0] == '\0')
		goto err_kfree;

	pstr.name[pstr.len] = '\0';
	set_delayed_call(done, kfree_link, pstr.name);
	return pstr.name;

err_kfree:
	kfree(pstr.name);
	return ERR_PTR(err);
}
コード例 #3
0
ファイル: dir.c プロジェクト: SantoshShilimkar/linux
static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
			bool excl)
{
	struct inode *inode;
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
					.dirtied_ino = 1 };
	struct ubifs_inode *dir_ui = ubifs_inode(dir);
	struct fscrypt_name nm;
	int err, sz_change;

	/*
	 * Budget request settings: new inode, new direntry, changing the
	 * parent directory inode.
	 */

	dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
		dentry, mode, dir->i_ino);

	err = ubifs_budget_space(c, &req);
	if (err)
		return err;

	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
	if (err)
		goto out_budg;

	sz_change = CALC_DENT_SIZE(fname_len(&nm));

	inode = ubifs_new_inode(c, dir, mode);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_fname;
	}

	err = ubifs_init_security(dir, inode, &dentry->d_name);
	if (err)
		goto out_inode;

	mutex_lock(&dir_ui->ui_mutex);
	dir->i_size += sz_change;
	dir_ui->ui_size = dir->i_size;
	dir->i_mtime = dir->i_ctime = inode->i_ctime;
	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
	if (err)
		goto out_cancel;
	mutex_unlock(&dir_ui->ui_mutex);

	ubifs_release_budget(c, &req);
	fscrypt_free_filename(&nm);
	insert_inode_hash(inode);
	d_instantiate(dentry, inode);
	return 0;

out_cancel:
	dir->i_size -= sz_change;
	dir_ui->ui_size = dir->i_size;
	mutex_unlock(&dir_ui->ui_mutex);
out_inode:
	make_bad_inode(inode);
	iput(inode);
out_fname:
	fscrypt_free_filename(&nm);
out_budg:
	ubifs_release_budget(c, &req);
	ubifs_err(c, "cannot create regular file, error %d", err);
	return err;
}

static int do_tmpfile(struct inode *dir, struct dentry *dentry,
		      umode_t mode, struct inode **whiteout)
{
	struct inode *inode;
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1};
	struct ubifs_budget_req ino_req = { .dirtied_ino = 1 };
	struct ubifs_inode *ui, *dir_ui = ubifs_inode(dir);
	int err, instantiated = 0;
	struct fscrypt_name nm;

	/*
	 * Budget request settings: new dirty inode, new direntry,
	 * budget for dirtied inode will be released via writeback.
	 */

	dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
		dentry, mode, dir->i_ino);

	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
	if (err)
		return err;

	err = ubifs_budget_space(c, &req);
	if (err) {
		fscrypt_free_filename(&nm);
		return err;
	}

	err = ubifs_budget_space(c, &ino_req);
	if (err) {
		ubifs_release_budget(c, &req);
		fscrypt_free_filename(&nm);
		return err;
	}

	inode = ubifs_new_inode(c, dir, mode);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_budg;
	}
	ui = ubifs_inode(inode);

	if (whiteout) {
		init_special_inode(inode, inode->i_mode, WHITEOUT_DEV);
		ubifs_assert(inode->i_op == &ubifs_file_inode_operations);
	}

	err = ubifs_init_security(dir, inode, &dentry->d_name);
	if (err)
		goto out_inode;

	mutex_lock(&ui->ui_mutex);
	insert_inode_hash(inode);

	if (whiteout) {
		mark_inode_dirty(inode);
		drop_nlink(inode);
		*whiteout = inode;
	} else {
		d_tmpfile(dentry, inode);
	}
	ubifs_assert(ui->dirty);

	instantiated = 1;
	mutex_unlock(&ui->ui_mutex);

	mutex_lock(&dir_ui->ui_mutex);
	err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
	if (err)
		goto out_cancel;
	mutex_unlock(&dir_ui->ui_mutex);

	ubifs_release_budget(c, &req);

	return 0;

out_cancel:
	mutex_unlock(&dir_ui->ui_mutex);
out_inode:
	make_bad_inode(inode);
	if (!instantiated)
		iput(inode);
out_budg:
	ubifs_release_budget(c, &req);
	if (!instantiated)
		ubifs_release_budget(c, &ino_req);
	fscrypt_free_filename(&nm);
	ubifs_err(c, "cannot create temporary file, error %d", err);
	return err;
}

static int ubifs_tmpfile(struct inode *dir, struct dentry *dentry,
			 umode_t mode)
{
	return do_tmpfile(dir, dentry, mode, NULL);
}

/**
 * vfs_dent_type - get VFS directory entry type.
 * @type: UBIFS directory entry type
 *
 * This function converts UBIFS directory entry type into VFS directory entry
 * type.
 */
static unsigned int vfs_dent_type(uint8_t type)
{
	switch (type) {
	case UBIFS_ITYPE_REG:
		return DT_REG;
	case UBIFS_ITYPE_DIR:
		return DT_DIR;
	case UBIFS_ITYPE_LNK:
		return DT_LNK;
	case UBIFS_ITYPE_BLK:
		return DT_BLK;
	case UBIFS_ITYPE_CHR:
		return DT_CHR;
	case UBIFS_ITYPE_FIFO:
		return DT_FIFO;
	case UBIFS_ITYPE_SOCK:
		return DT_SOCK;
	default:
		BUG();
	}
	return 0;
}

/*
 * The classical Unix view for directory is that it is a linear array of
 * (name, inode number) entries. Linux/VFS assumes this model as well.
 * Particularly, 'readdir()' call wants us to return a directory entry offset
 * which later may be used to continue 'readdir()'ing the directory or to
 * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this
 * model because directory entries are identified by keys, which may collide.
 *
 * UBIFS uses directory entry hash value for directory offsets, so
 * 'seekdir()'/'telldir()' may not always work because of possible key
 * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work
 * properly by means of saving full directory entry name in the private field
 * of the file description object.
 *
 * This means that UBIFS cannot support NFS which requires full
 * 'seekdir()'/'telldir()' support.
 */
static int ubifs_readdir(struct file *file, struct dir_context *ctx)
{
	int fstr_real_len = 0, err = 0;
	struct fscrypt_name nm;
	struct fscrypt_str fstr = {0};
	union ubifs_key key;
	struct ubifs_dent_node *dent;
	struct inode *dir = file_inode(file);
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	bool encrypted = ubifs_crypt_is_encrypted(dir);

	dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, ctx->pos);

	if (ctx->pos > UBIFS_S_KEY_HASH_MASK || ctx->pos == 2)
		/*
		 * The directory was seek'ed to a senseless position or there
		 * are no more entries.
		 */
		return 0;

	if (encrypted) {
		err = fscrypt_get_encryption_info(dir);
		if (err && err != -ENOKEY)
			return err;

		err = fscrypt_fname_alloc_buffer(dir, UBIFS_MAX_NLEN, &fstr);
		if (err)
			return err;

		fstr_real_len = fstr.len;
	}

	if (file->f_version == 0) {
		/*
		 * The file was seek'ed, which means that @file->private_data
		 * is now invalid. This may also be just the first
		 * 'ubifs_readdir()' invocation, in which case
		 * @file->private_data is NULL, and the below code is
		 * basically a no-op.
		 */
		kfree(file->private_data);
		file->private_data = NULL;
	}

	/*
	 * 'generic_file_llseek()' unconditionally sets @file->f_version to
	 * zero, and we use this for detecting whether the file was seek'ed.
	 */
	file->f_version = 1;

	/* File positions 0 and 1 correspond to "." and ".." */
	if (ctx->pos < 2) {
		ubifs_assert(!file->private_data);
		if (!dir_emit_dots(file, ctx)) {
			if (encrypted)
				fscrypt_fname_free_buffer(&fstr);
			return 0;
		}

		/* Find the first entry in TNC and save it */
		lowest_dent_key(c, &key, dir->i_ino);
		fname_len(&nm) = 0;
		dent = ubifs_tnc_next_ent(c, &key, &nm);
		if (IS_ERR(dent)) {
			err = PTR_ERR(dent);
			goto out;
		}

		ctx->pos = key_hash_flash(c, &dent->key);
		file->private_data = dent;
	}

	dent = file->private_data;
	if (!dent) {
		/*
		 * The directory was seek'ed to and is now readdir'ed.
		 * Find the entry corresponding to @ctx->pos or the closest one.
		 */
		dent_key_init_hash(c, &key, dir->i_ino, ctx->pos);
		fname_len(&nm) = 0;
		dent = ubifs_tnc_next_ent(c, &key, &nm);
		if (IS_ERR(dent)) {
			err = PTR_ERR(dent);
			goto out;
		}
		ctx->pos = key_hash_flash(c, &dent->key);
		file->private_data = dent;
	}

	while (1) {
		dbg_gen("ino %llu, new f_pos %#x",
			(unsigned long long)le64_to_cpu(dent->inum),
			key_hash_flash(c, &dent->key));
		ubifs_assert(le64_to_cpu(dent->ch.sqnum) >
			     ubifs_inode(dir)->creat_sqnum);

		fname_len(&nm) = le16_to_cpu(dent->nlen);
		fname_name(&nm) = dent->name;

		if (encrypted) {
			fstr.len = fstr_real_len;

			err = fscrypt_fname_disk_to_usr(dir, key_hash_flash(c,
							&dent->key),
							le32_to_cpu(dent->cookie),
							&nm.disk_name, &fstr);
			if (err)
				goto out;
		} else {
			fstr.len = fname_len(&nm);
			fstr.name = fname_name(&nm);
		}

		if (!dir_emit(ctx, fstr.name, fstr.len,
			       le64_to_cpu(dent->inum),
			       vfs_dent_type(dent->type))) {
			if (encrypted)
				fscrypt_fname_free_buffer(&fstr);
			return 0;
		}

		/* Switch to the next entry */
		key_read(c, &dent->key, &key);
		dent = ubifs_tnc_next_ent(c, &key, &nm);
		if (IS_ERR(dent)) {
			err = PTR_ERR(dent);
			goto out;
		}

		kfree(file->private_data);
		ctx->pos = key_hash_flash(c, &dent->key);
		file->private_data = dent;
		cond_resched();
	}

out:
	kfree(file->private_data);
	file->private_data = NULL;

	if (encrypted)
		fscrypt_fname_free_buffer(&fstr);

	if (err != -ENOENT)
		ubifs_err(c, "cannot find next direntry, error %d", err);
	else
		/*
		 * -ENOENT is a non-fatal error in this context, the TNC uses
		 * it to indicate that the cursor moved past the current directory
		 * and readdir() has to stop.
		 */
		err = 0;


	/* 2 is a special value indicating that there are no more direntries */
	ctx->pos = 2;
	return err;
}

/* Free saved readdir() state when the directory is closed */
static int ubifs_dir_release(struct inode *dir, struct file *file)
{
	kfree(file->private_data);
	file->private_data = NULL;
	return 0;
}

/**
 * lock_2_inodes - a wrapper for locking two UBIFS inodes.
 * @inode1: first inode
 * @inode2: second inode
 *
 * We do not implement any tricks to guarantee strict lock ordering, because
 * VFS has already done it for us on the @i_mutex. So this is just a simple
 * wrapper function.
 */
static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
{
	mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
	mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
}
コード例 #4
0
ファイル: namei.c プロジェクト: StanTRC/boeffla-kernel-cm-s5
struct dentry *f2fs_get_parent(struct dentry *child)
{
	struct qstr dotdot = {.len = 2, .name = ".."};
	struct page *page;
	unsigned long ino = f2fs_inode_by_name(d_inode(child), &dotdot, &page);
	if (!ino) {
		if (IS_ERR(page))
			return ERR_CAST(page);
		return ERR_PTR(-ENOENT);
	}
	return d_obtain_alias(f2fs_iget(child->d_sb, ino));
}

static int __recover_dot_dentries(struct inode *dir, nid_t pino)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	struct qstr dot = QSTR_INIT(".", 1);
	struct qstr dotdot = QSTR_INIT("..", 2);
	struct f2fs_dir_entry *de;
	struct page *page;
	int err = 0;

	if (f2fs_readonly(sbi->sb)) {
		f2fs_msg(sbi->sb, KERN_INFO,
			"skip recovering inline_dots inode (ino:%lu, pino:%u) "
			"in readonly mountpoint", dir->i_ino, pino);
		return 0;
	}

	f2fs_balance_fs(sbi, true);

	f2fs_lock_op(sbi);

	de = f2fs_find_entry(dir, &dot, &page);
	if (de) {
		f2fs_dentry_kunmap(dir, page);
		f2fs_put_page(page, 0);
	} else if (IS_ERR(page)) {
		err = PTR_ERR(page);
		goto out;
	} else {
		err = __f2fs_add_link(dir, &dot, NULL, dir->i_ino, S_IFDIR);
		if (err)
			goto out;
	}

	de = f2fs_find_entry(dir, &dotdot, &page);
	if (de) {
		f2fs_dentry_kunmap(dir, page);
		f2fs_put_page(page, 0);
	} else if (IS_ERR(page)) {
		err = PTR_ERR(page);
	} else {
		err = __f2fs_add_link(dir, &dotdot, NULL, pino, S_IFDIR);
	}
out:
	if (!err)
		clear_inode_flag(dir, FI_INLINE_DOTS);

	f2fs_unlock_op(sbi);
	return err;
}

static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
					struct nameidata *nd)
{
	struct inode *inode = NULL;
	struct f2fs_dir_entry *de;
	struct page *page;
	nid_t ino;
	int err = 0;
	unsigned int root_ino = F2FS_ROOT_INO(F2FS_I_SB(dir));

	if (f2fs_encrypted_inode(dir)) {
		int res = fscrypt_get_encryption_info(dir);

		/*
		 * DCACHE_ENCRYPTED_WITH_KEY is set if the dentry is
		 * created while the directory was encrypted and we
		 * don't have access to the key.
		 */
		if (fscrypt_has_encryption_key(dir))
			fscrypt_set_encrypted_dentry(dentry);
		fscrypt_set_d_op(dentry);
		if (res && res != -ENOKEY)
			return ERR_PTR(res);
	}

	if (dentry->d_name.len > F2FS_NAME_LEN)
		return ERR_PTR(-ENAMETOOLONG);

	de = f2fs_find_entry(dir, &dentry->d_name, &page);
	if (!de) {
		if (IS_ERR(page))
			return (struct dentry *)page;
		return d_splice_alias(inode, dentry);
	}

	ino = le32_to_cpu(de->ino);
	f2fs_dentry_kunmap(dir, page);
	f2fs_put_page(page, 0);

	inode = f2fs_iget(dir->i_sb, ino);
	if (IS_ERR(inode))
		return ERR_CAST(inode);

	if ((dir->i_ino == root_ino) && f2fs_has_inline_dots(dir)) {
		err = __recover_dot_dentries(dir, root_ino);
		if (err)
			goto err_out;
	}

	if (f2fs_has_inline_dots(inode)) {
		err = __recover_dot_dentries(inode, dir->i_ino);
		if (err)
			goto err_out;
	}
	if (!IS_ERR(inode) && f2fs_encrypted_inode(dir) &&
			(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
			!fscrypt_has_permitted_context(dir, inode)) {
		bool nokey = f2fs_encrypted_inode(inode) &&
			!fscrypt_has_encryption_key(inode);
		err = nokey ? -ENOKEY : -EPERM;
		goto err_out;
	}
	return d_splice_alias(inode, dentry);

err_out:
	iput(inode);
	return ERR_PTR(err);
}

static int f2fs_unlink(struct inode *dir, struct dentry *dentry)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	struct inode *inode = d_inode(dentry);
	struct f2fs_dir_entry *de;
	struct page *page;
	int err = -ENOENT;

	trace_f2fs_unlink_enter(dir, dentry);

	de = f2fs_find_entry(dir, &dentry->d_name, &page);
	if (!de) {
		if (IS_ERR(page))
			err = PTR_ERR(page);
		goto fail;
	}

	f2fs_balance_fs(sbi, true);

	f2fs_lock_op(sbi);
	err = acquire_orphan_inode(sbi);
	if (err) {
		f2fs_unlock_op(sbi);
		f2fs_dentry_kunmap(dir, page);
		f2fs_put_page(page, 0);
		goto fail;
	}
	f2fs_delete_entry(de, page, dir, inode);
	f2fs_unlock_op(sbi);

	if (IS_DIRSYNC(dir))
		f2fs_sync_fs(sbi->sb, 1);
fail:
	trace_f2fs_unlink_exit(inode, err);
	return err;
}

static void *f2fs_follow_link(struct dentry *dentry, struct nameidata *nd)
{
	struct page *page;
	char *link;

	page = page_follow_link_light(dentry, nd);
	if (IS_ERR(page))
		return page;

	link = nd_get_link(nd);
	if (IS_ERR(link))
		return link;

	/* this is broken symlink case */
	if (*link == 0) {
		kunmap(page);
		page_cache_release(page);
		return ERR_PTR(-ENOENT);
	}
	return page;
}

static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
					const char *symname)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	struct inode *inode;
	size_t len = strlen(symname);
	struct fscrypt_str disk_link = FSTR_INIT((char *)symname, len + 1);
	struct fscrypt_symlink_data *sd = NULL;
	int err;

	if (f2fs_encrypted_inode(dir)) {
		err = fscrypt_get_encryption_info(dir);
		if (err)
			return err;

		if (!fscrypt_has_encryption_key(dir))
			return -EPERM;

		disk_link.len = (fscrypt_fname_encrypted_size(dir, len) +
				sizeof(struct fscrypt_symlink_data));
	}

	if (disk_link.len > dir->i_sb->s_blocksize)
		return -ENAMETOOLONG;

	inode = f2fs_new_inode(dir, S_IFLNK | S_IRWXUGO);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	if (f2fs_encrypted_inode(inode))
		inode->i_op = &f2fs_encrypted_symlink_inode_operations;
	else
		inode->i_op = &f2fs_symlink_inode_operations;
	inode_nohighmem(inode);
	inode->i_mapping->a_ops = &f2fs_dblock_aops;

	f2fs_balance_fs(sbi, true);

	f2fs_lock_op(sbi);
	err = f2fs_add_link(dentry, inode);
	if (err)
		goto out;
	f2fs_unlock_op(sbi);
	alloc_nid_done(sbi, inode->i_ino);

	if (f2fs_encrypted_inode(inode)) {
		struct qstr istr = QSTR_INIT(symname, len);
		struct fscrypt_str ostr;

		sd = kzalloc(disk_link.len, GFP_NOFS);
		if (!sd) {
			err = -ENOMEM;
			goto err_out;
		}

		err = fscrypt_get_encryption_info(inode);
		if (err)
			goto err_out;

		if (!fscrypt_has_encryption_key(inode)) {
			err = -EPERM;
			goto err_out;
		}

		ostr.name = sd->encrypted_path;
		ostr.len = disk_link.len;
		err = fscrypt_fname_usr_to_disk(inode, &istr, &ostr);
		if (err < 0)
			goto err_out;

		sd->len = cpu_to_le16(ostr.len);
		disk_link.name = (char *)sd;
	}

	err = page_symlink(inode, disk_link.name, disk_link.len);

err_out:
	d_instantiate(dentry, inode);
	unlock_new_inode(inode);

	/*
	 * Let's flush symlink data in order to avoid broken symlink as much as
	 * possible. Nevertheless, fsyncing is the best way, but there is no
	 * way to get a file descriptor in order to flush that.
	 *
	 * Note that, it needs to do dir->fsync to make this recoverable.
	 * If the symlink path is stored into inline_data, there is no
	 * performance regression.
	 */
	if (!err) {
		filemap_write_and_wait_range(inode->i_mapping, 0,
							disk_link.len - 1);

		if (IS_DIRSYNC(dir))
			f2fs_sync_fs(sbi->sb, 1);
	} else {
		f2fs_unlink(dir, dentry);
	}

	kfree(sd);
	return err;
out:
	handle_failed_inode(inode);
	return err;
}

static int f2fs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	struct inode *inode;
	int err;

	inode = f2fs_new_inode(dir, S_IFDIR | mode);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	inode->i_op = &f2fs_dir_inode_operations;
	inode->i_fop = &f2fs_dir_operations;
	inode->i_mapping->a_ops = &f2fs_dblock_aops;
	mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_HIGH_ZERO);

	f2fs_balance_fs(sbi, true);

	set_inode_flag(inode, FI_INC_LINK);
	f2fs_lock_op(sbi);
	err = f2fs_add_link(dentry, inode);
	if (err)
		goto out_fail;
	f2fs_unlock_op(sbi);

	alloc_nid_done(sbi, inode->i_ino);

	d_instantiate(dentry, inode);
	unlock_new_inode(inode);

	if (IS_DIRSYNC(dir))
		f2fs_sync_fs(sbi->sb, 1);
	return 0;

out_fail:
	clear_inode_flag(inode, FI_INC_LINK);
	handle_failed_inode(inode);
	return err;
}

static int f2fs_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = d_inode(dentry);
	if (f2fs_empty_dir(inode))
		return f2fs_unlink(dir, dentry);
	return -ENOTEMPTY;
}

static int f2fs_mknod(struct inode *dir, struct dentry *dentry,
				umode_t mode, dev_t rdev)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	struct inode *inode;
	int err = 0;

	if (!new_valid_dev(rdev))
		return -EINVAL;

	inode = f2fs_new_inode(dir, mode);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	init_special_inode(inode, inode->i_mode, rdev);
	inode->i_op = &f2fs_special_inode_operations;

	f2fs_balance_fs(sbi, true);

	f2fs_lock_op(sbi);
	err = f2fs_add_link(dentry, inode);
	if (err)
		goto out;
	f2fs_unlock_op(sbi);

	alloc_nid_done(sbi, inode->i_ino);

	d_instantiate(dentry, inode);
	unlock_new_inode(inode);

	if (IS_DIRSYNC(dir))
		f2fs_sync_fs(sbi->sb, 1);
	return 0;
out:
	handle_failed_inode(inode);
	return err;
}

static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
			struct inode *new_dir, struct dentry *new_dentry)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(old_dir);
	struct inode *old_inode = d_inode(old_dentry);
	struct inode *new_inode = d_inode(new_dentry);
	struct page *old_dir_page;
	struct page *old_page, *new_page;
	struct f2fs_dir_entry *old_dir_entry = NULL;
	struct f2fs_dir_entry *old_entry;
	struct f2fs_dir_entry *new_entry;
	bool is_old_inline = f2fs_has_inline_dentry(old_dir);
	int err = -ENOENT;

	if ((old_dir != new_dir) && f2fs_encrypted_inode(new_dir) &&
			!fscrypt_has_permitted_context(new_dir, old_inode)) {
		err = -EPERM;
		goto out;
	}

	old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
	if (!old_entry) {
		if (IS_ERR(old_page))
			err = PTR_ERR(old_page);
		goto out;
	}

	if (S_ISDIR(old_inode->i_mode)) {
		old_dir_entry = f2fs_parent_dir(old_inode, &old_dir_page);
		if (!old_dir_entry) {
			if (IS_ERR(old_dir_page))
				err = PTR_ERR(old_dir_page);
			goto out_old;
		}
	}

	if (new_inode) {

		err = -ENOTEMPTY;
		if (old_dir_entry && !f2fs_empty_dir(new_inode))
			goto out_dir;

		err = -ENOENT;
		new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name,
						&new_page);
		if (!new_entry) {
			if (IS_ERR(new_page))
				err = PTR_ERR(new_page);
			goto out_dir;
		}

		f2fs_balance_fs(sbi, true);

		f2fs_lock_op(sbi);

		err = acquire_orphan_inode(sbi);
		if (err)
			goto put_out_dir;

		err = update_dent_inode(old_inode, new_inode,
						&new_dentry->d_name);
		if (err) {
			release_orphan_inode(sbi);
			goto put_out_dir;
		}

		f2fs_set_link(new_dir, new_entry, new_page, old_inode);

		new_inode->i_ctime = CURRENT_TIME;
		down_write(&F2FS_I(new_inode)->i_sem);
		if (old_dir_entry)
			f2fs_i_links_write(new_inode, false);
		f2fs_i_links_write(new_inode, false);
		up_write(&F2FS_I(new_inode)->i_sem);

		if (!new_inode->i_nlink)
			add_orphan_inode(new_inode);
		else
			release_orphan_inode(sbi);
	} else {
		f2fs_balance_fs(sbi, true);

		f2fs_lock_op(sbi);

		err = f2fs_add_link(new_dentry, old_inode);
		if (err) {
			f2fs_unlock_op(sbi);
			goto out_dir;
		}

		if (old_dir_entry)
			f2fs_i_links_write(new_dir, true);

		/*
		 * old entry and new entry can locate in the same inline
		 * dentry in inode, when attaching new entry in inline dentry,
		 * it could force inline dentry conversion, after that,
		 * old_entry and old_page will point to wrong address, in
		 * order to avoid this, let's do the check and update here.
		 */
		if (is_old_inline && !f2fs_has_inline_dentry(old_dir)) {
			f2fs_put_page(old_page, 0);
			old_page = NULL;

			old_entry = f2fs_find_entry(old_dir,
						&old_dentry->d_name, &old_page);
			if (!old_entry) {
				err = -ENOENT;
				if (IS_ERR(old_page))
					err = PTR_ERR(old_page);
				f2fs_unlock_op(sbi);
				goto out_dir;
			}
		}
	}

	down_write(&F2FS_I(old_inode)->i_sem);
	file_lost_pino(old_inode);
	if (new_inode && file_enc_name(new_inode))
		file_set_enc_name(old_inode);
	up_write(&F2FS_I(old_inode)->i_sem);

	old_inode->i_ctime = CURRENT_TIME;
	f2fs_mark_inode_dirty_sync(old_inode);

	f2fs_delete_entry(old_entry, old_page, old_dir, NULL);

	if (old_dir_entry) {
		if (old_dir != new_dir) {
			f2fs_set_link(old_inode, old_dir_entry,
						old_dir_page, new_dir);
		} else {
			f2fs_dentry_kunmap(old_inode, old_dir_page);
			f2fs_put_page(old_dir_page, 0);
		}
		f2fs_i_links_write(old_dir, false);
	}

	f2fs_unlock_op(sbi);

	if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
		f2fs_sync_fs(sbi->sb, 1);
	return 0;

put_out_dir:
	f2fs_unlock_op(sbi);
	f2fs_dentry_kunmap(new_dir, new_page);
	f2fs_put_page(new_page, 0);
out_dir:
	if (old_dir_entry) {
		f2fs_dentry_kunmap(old_inode, old_dir_page);
		f2fs_put_page(old_dir_page, 0);
	}
out_old:
	f2fs_dentry_kunmap(old_dir, old_page);
	f2fs_put_page(old_page, 0);
out:
	return err;
}

static void *f2fs_encrypted_follow_link(struct dentry *dentry,
						struct nameidata *nd)
{
	struct page *cpage = NULL;
	char *caddr, *paddr = NULL;
	struct fscrypt_str cstr = FSTR_INIT(NULL, 0);
	struct fscrypt_str pstr = FSTR_INIT(NULL, 0);
	struct fscrypt_symlink_data *sd;
	struct inode *inode = d_inode(dentry);
	loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1);
	u32 max_size = inode->i_sb->s_blocksize;
	int res;

	res = fscrypt_get_encryption_info(inode);
	if (res)
		return ERR_PTR(res);

	cpage = read_mapping_page(inode->i_mapping, 0, NULL);
	if (IS_ERR(cpage))
		return cpage;
	caddr = kmap(cpage);
	caddr[size] = 0;

	/* Symlink is encrypted */
	sd = (struct fscrypt_symlink_data *)caddr;
	cstr.name = sd->encrypted_path;
	cstr.len = le16_to_cpu(sd->len);

	/* this is broken symlink case */
	if (unlikely(cstr.len == 0)) {
		res = -ENOENT;
		goto errout;
	}

	if ((cstr.len + sizeof(struct fscrypt_symlink_data) - 1) > max_size) {
		/* Symlink data on the disk is corrupted */
		res = -EIO;
		goto errout;
	}
	res = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr);
	if (res)
		goto errout;

	res = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr);
	if (res < 0)
		goto errout;

	/* this is broken symlink case */
	if (unlikely(pstr.name[0] == 0)) {
		res = -ENOENT;
		goto errout;
	}

	paddr = pstr.name;

	/* Null-terminate the name */
	paddr[res] = '\0';
	nd_set_link(nd, paddr);

	kunmap(cpage);
	page_cache_release(cpage);
	return NULL;
errout:
	fscrypt_fname_free_buffer(&pstr);
	kunmap(cpage);
	page_cache_release(cpage);
	return ERR_PTR(res);
}

void kfree_put_link(struct dentry *dentry, struct nameidata *nd,
		void *cookie)
{
	char *s = nd_get_link(nd);
	if (!IS_ERR(s))
		kfree(s);
}
コード例 #5
0
ファイル: namei.c プロジェクト: mdamt/linux
static const char *f2fs_encrypted_get_link(struct dentry *dentry,
					   struct inode *inode,
					   struct delayed_call *done)
{
	struct page *cpage = NULL;
	char *caddr, *paddr = NULL;
	struct fscrypt_str cstr = FSTR_INIT(NULL, 0);
	struct fscrypt_str pstr = FSTR_INIT(NULL, 0);
	struct fscrypt_symlink_data *sd;
	u32 max_size = inode->i_sb->s_blocksize;
	int res;

	if (!dentry)
		return ERR_PTR(-ECHILD);

	res = fscrypt_get_encryption_info(inode);
	if (res)
		return ERR_PTR(res);

	cpage = read_mapping_page(inode->i_mapping, 0, NULL);
	if (IS_ERR(cpage))
		return ERR_CAST(cpage);
	caddr = page_address(cpage);

	/* Symlink is encrypted */
	sd = (struct fscrypt_symlink_data *)caddr;
	cstr.name = sd->encrypted_path;
	cstr.len = le16_to_cpu(sd->len);

	/* this is broken symlink case */
	if (unlikely(cstr.len == 0)) {
		res = -ENOENT;
		goto errout;
	}

	if ((cstr.len + sizeof(struct fscrypt_symlink_data) - 1) > max_size) {
		/* Symlink data on the disk is corrupted */
		res = -EIO;
		goto errout;
	}
	res = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr);
	if (res)
		goto errout;

	res = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr);
	if (res)
		goto errout;

	/* this is broken symlink case */
	if (unlikely(pstr.name[0] == 0)) {
		res = -ENOENT;
		goto errout;
	}

	paddr = pstr.name;

	/* Null-terminate the name */
	paddr[pstr.len] = '\0';

	put_page(cpage);
	set_delayed_call(done, kfree_link, paddr);
	return paddr;
errout:
	fscrypt_fname_free_buffer(&pstr);
	put_page(cpage);
	return ERR_PTR(res);
}