isofs: basic improvements

- fix for "out of extents" panic;
- return ENOENT when a file name does not exist;
- inode count sanity check upon unmount.

Change-Id: Icb97dbaf7c8aec463438f06b341defca357094b2

minix/fs/iso9660fs/inode.c

@@ -212,6 +212,7 @@ void read_inode_iso9660(struct inode *i,
 
 	/* Parse first extent. */
 	if (dir_rec->data_length_l > 0) {
+		assert(i->extent == NULL);
 		i->extent = alloc_extent();
 		i->extent->location = dir_rec->loc_extent_l +
 		                      dir_rec->ext_attr_rec_length;
@@ -299,6 +300,7 @@ void read_inode_extents(struct inode *i,
 		    (memcmp(dir_rec->file_id, extent_rec->file_id,
 		    dir_rec->length_file_id) == 0)) {
 			/* Add the extent at the end of the linked list. */
+			assert(cur_extent->next == NULL);
 			cur_extent->next = alloc_extent();
 			cur_extent->next->location = dir_rec->loc_extent_l +
 			    dir_rec->ext_attr_rec_length;
@@ -388,3 +390,15 @@ int check_dir_record(const struct iso9660_dir_record *d, size_t offset)
 
 	return OK;
 }
+
+int check_inodes(void)
+{
+	/* Check whether there are no more inodes in use. Called on unmount. */
+	int i;
+
+	for (i = 0; i < NR_INODE_RECORDS; i++)
+		if (inodes[i].i_count > 0)
+			return FALSE;
+
+	return TRUE;
+}

minix/fs/iso9660fs/mount.c

@@ -60,4 +60,7 @@ void fs_unmount(void)
 	release_vol_pri_desc(&v_pri);	/* Release the super block */
 
 	bdev_close(fs_dev);
+
+	if (check_inodes() == FALSE)
+		printf("ISOFS: unmounting with in-use inodes!\n");
 }

minix/fs/iso9660fs/path.c

@@ -41,12 +41,16 @@ static int search_dir(
 			r = read_inode(dir_tmp, ldir_ptr->extent, pos, &pos);
 			if ((r != OK) || (pos >= ldir_ptr->i_stat.st_size)) {
 				put_inode(dir_tmp);
-				return EINVAL;
+				return ENOENT;
 			}
+			/* Temporary fix for extent spilling */
+			put_inode(dir_tmp);
+			dir_tmp = alloc_inode();
+			/* End of fix */
 			r = read_inode(dir_tmp, ldir_ptr->extent, pos, &pos);
 			if ((r != OK) || (pos >= ldir_ptr->i_stat.st_size)) {
 				put_inode(dir_tmp);
-				return EINVAL;
+				return ENOENT;
 			}
 			*numb = dir_tmp->i_stat.st_ino;
 			put_inode(dir_tmp);
@@ -60,7 +64,7 @@ static int search_dir(
 		r = read_inode(dir_tmp, ldir_ptr->extent, pos, &pos);
 		if ((r != OK) || (pos >= ldir_ptr->i_stat.st_size)) {
 			put_inode(dir_tmp);
-			return EINVAL;
+			return ENOENT;
 		}
 
 		if ((strcmp(dir_tmp->i_name, string) == 0) ||

minix/fs/iso9660fs/proto.h

@@ -28,6 +28,8 @@ void read_inode_susp(struct inode *i, const struct iso9660_dir_record *dir_rec,
 
 int check_dir_record(const struct iso9660_dir_record *d, size_t offset);
 
+int check_inodes(void);
+
 /* link.c */
 ssize_t fs_rdlink(ino_t ino_nr, struct fsdriver_data *data, size_t bytes);