add ntfs_link, update ntfsmount to use it

include/ntfs/dir.h

@@ -44,6 +44,8 @@ extern ntfs_inode *ntfs_create(ntfs_inode *dir_ni, ntfschar *name, u8 name_len,
 		const unsigned type);
 extern int ntfs_delete(ntfs_inode *ni, ntfs_inode *dir_ni, ntfschar *name,
 		u8 name_len);
+extern int ntfs_link(ntfs_inode *ni, ntfs_inode *dir_ni, ntfschar *name,
+		u8 name_len);
 
 /*
  * File types (adapted from include <linux/fs.h>)

libntfs/dir.c

@@ -1406,3 +1406,96 @@ err_out:
 	err = errno;
 	goto out;
 }
+
+/**
+ * ntfs_link - create hard link for file or directory
+ * @ni:		ntfs inode for object to create hard link
+ * @dir_ni:	ntfs inode for directory in which new link should be placed
+ * @name:	unicode name of the new link
+ * @name_len:	length of the name in unicode characters
+ *
+ * Return 0 on success or -1 on error with errno set to the error code.
+ */
+int ntfs_link(ntfs_inode *ni, ntfs_inode *dir_ni, ntfschar *name, u8 name_len)
+{
+	FILE_NAME_ATTR *fn = NULL;
+	int fn_len, err;
+
+	ntfs_debug("Entering.");
+	if (!ni || !dir_ni || !name || !name_len) {
+		err = errno;
+		ntfs_error(, "Invalid arguments.");
+		goto err_out;
+	}
+	/* Create FILE_NAME attribute. */
+	fn_len = sizeof(FILE_NAME_ATTR) + name_len * sizeof(ntfschar);
+	fn = calloc(1, fn_len);
+	if (!fn) {
+		err = errno;
+		ntfs_error(, "Not enough memory.");
+		goto err_out;
+	}
+	fn->parent_directory = MK_LE_MREF(dir_ni->mft_no,
+			le16_to_cpu(dir_ni->mrec->sequence_number));
+	fn->file_name_length = name_len;
+	fn->file_name_type = FILE_NAME_POSIX;
+	if (ni->mrec->flags & MFT_RECORD_IS_DIRECTORY)
+		fn->file_attributes = FILE_ATTR_DUP_FILE_NAME_INDEX_PRESENT;
+	fn->creation_time = utc2ntfs(ni->creation_time);
+	fn->last_data_change_time = utc2ntfs(ni->last_data_change_time);
+	fn->last_mft_change_time = utc2ntfs(ni->last_mft_change_time);
+	fn->last_access_time = utc2ntfs(ni->last_access_time);
+	memcpy(fn->file_name, name, name_len * sizeof(ntfschar));
+	/* Add FILE_NAME attribute to index. */
+	if (ntfs_index_add_filename(dir_ni, fn, MK_MREF(ni->mft_no,
+			le16_to_cpu(ni->mrec->sequence_number)))) {
+		err = errno;
+		ntfs_error(, "Failed to add entry to the index.");
+		goto err_out;
+	}
+	/* Add FILE_NAME attribute to inode. */
+	if (ntfs_attr_add(ni, AT_FILE_NAME, AT_UNNAMED, 0, (u8*)fn, fn_len)) {
+		ntfs_index_context *ictx;
+
+		err = errno;
+		ntfs_error(, "Failed to add FILE_NAME attribute.");
+		/* Try to remove just added attribute from index. */
+		ictx = ntfs_index_ctx_get(dir_ni, I30, 4);
+		if (!ictx)
+			goto rollback_failed;
+		if (ntfs_index_lookup(fn, fn_len, ictx)) {
+			ntfs_index_ctx_put(ictx);
+			goto rollback_failed;
+		}
+		if (ntfs_index_rm(ictx)) {
+			ntfs_index_ctx_put(ictx);
+			goto rollback_failed;
+		}
+		goto err_out;
+	}
+	/* Increment hard links count. */
+	ni->mrec->link_count = cpu_to_le16(le16_to_cpu(
+			ni->mrec->link_count) + 1);
+	/*
+	 * Do not set attributes and file size, instead of this mark filenames
+	 * dirty to force attribute and size update during sync. 
+	 * NOTE: File size may will be not updated and not all attributes will
+	 * be set, but it is acceptable since windows driver does not update
+	 * all file names when one of the hard links changed.
+	 * FIXME: It will be nice to update them all.
+	 */
+	NInoFileNameSetDirty(ni);
+	/* Done! */
+	ntfs_inode_mark_dirty(ni);
+	free(fn);
+	ntfs_debug("Done.");
+	return 0;
+rollback_failed:
+	ntfs_error(, "Rollback failed. Leaving inconsist metadata.");
+err_out:
+	ntfs_error(, "Failed.");
+	if (fn)
+		free(fn);
+	errno = err;
+	return -1;
+}

ntfsprogs/ntfsmount.c

@@ -628,6 +628,54 @@ static int ntfs_fuse_mknod(const char *org_path, mode_t mode,
 	return res;
 }
 
+static int ntfs_fuse_link(const char *old_path, const char *new_path)
+{
+	char *name;
+	ntfschar *uname = NULL;
+	ntfs_inode *dir_ni = NULL, *ni;
+	char *path;
+	int res = 0, uname_len;
+
+	path = strdup(new_path);
+	if (!path)
+		return -errno;
+	/* Open file for which create hard link. */
+	ni = ntfs_pathname_to_inode(ctx->vol, NULL, old_path);
+	if (!ni) {
+		res = -errno;
+		goto exit;
+	}
+	/* Generate unicode filename. */
+	name = strrchr(path, '/');
+	name++;
+	uname_len = ntfs_mbstoucs(name, &uname, 0);
+	if (uname_len < 0) {
+		res = -errno;
+		goto exit;
+	}
+	/* Open parent directory. */
+	*name = 0;
+	dir_ni = ntfs_pathname_to_inode(ctx->vol, NULL, path);
+	if (!dir_ni) {
+		res = -errno;
+		if (res == -ENOENT)
+			res = -EIO;
+		goto exit;
+	}
+	/* Create hard link. */
+	if (ntfs_link(ni, dir_ni, uname, uname_len))
+		res = -errno;
+exit:
+	if (ni)
+		ntfs_inode_close(ni);
+	if (uname)
+		free(uname);
+	if (dir_ni)
+		ntfs_inode_close(dir_ni);
+	free(path);
+	return res;
+}
+
 static int ntfs_fuse_rm(const char *org_path)
 {
 	char *name;
@@ -1042,6 +1090,7 @@ static struct fuse_operations ntfs_fuse_oper = {
 	.statfs		= ntfs_fuse_statfs,
 	.chmod		= ntfs_fuse_chmod,
 	.mknod		= ntfs_fuse_mknod,
+	.link		= ntfs_fuse_link,
 	.unlink		= ntfs_fuse_unlink,
 	.mkdir		= ntfs_fuse_mkdir,
 	.rmdir		= ntfs_fuse_rmdir,