[wip] add file creation, hardlinking, listing directory (in short and long formats)

config.h

@@ -5,6 +5,7 @@
 #define DEBUG 1
 #define LOG_LEVEL 4
 #define ENABLE_FILE_LINE_IN_OTHER_PR 1
+#define ENABLE_STDOUT 1
 
 
 /* Output color config section */

inc/color.h

@@ -8,10 +8,14 @@
 	#define COLOR_RESET "\e[0m"
 	#define COLOR_RED "\e[0;31m"
 	#define COLOR_YELLOW "\e[0;33m"
+	#define COLOR_BLUE "\e[0;34m"
+	#define COLOR_CYAN "\e[0;36m"
 #else
 	#define COLOR_RESET ""
 	#define COLOR_RED ""
 	#define COLOR_YELLOW ""
+	#define COLOR_BLUE ""
+	#define COLOR_CYAN ""
 #endif
 
 

inc/fs.h

@@ -36,7 +36,7 @@ struct fs_inode_extension {
 };
 
 __attribute__((packed))
-struct fs_directory_block_data {
+struct fs_directory_record {
 	unsigned char fname[60];
 	unsigned int inode_no;
 };
@@ -44,7 +44,10 @@ struct fs_directory_block_data {
 char *fs_get_cwd(void);
 
 int fs_create(void *d);
+int fs_ln(void *);
 int fs_use(void *d);
 int fs_mkfs(void *d);
+int fs_ls(void *d);
+int fs_la(void *d);
 int fs_allow_write(void *d);
 int fs_prohibit_write(void *d);

inc/print.h

@@ -13,6 +13,13 @@
 #endif
 
 
+#if ENABLE_STDOUT == 1
+	#define pr_stdout(...) { printf(__VA_ARGS__); }
+#else
+	#define pr_stdout(...) {}
+#endif
+
+
 #if LOG_LEVEL >= 2
 	#if ENABLE_FILE_LINE_IN_OTHER_PR == 1
 		#define pr_err(...) { \

src/cli.c

@@ -15,9 +15,12 @@ static const struct CliCommandEntry cmd[] = {
 	// mandatory commands
 	{"mkfs", 1, (enum CliArgType[]) {INT}, fs_mkfs},
 	{"create", 1, (enum CliArgType[]) {STR}, fs_create},
+	{"ls", 0, NULL, fs_ls},
+	{"ln", 2, (enum CliArgType[]) {STR, STR}, fs_ln},
 
 	// custom commands
 	{"use", 1, (enum CliArgType[]) {STR}, fs_use},
+	{"la", 0, NULL, fs_la},
 	{"prohibit-write", 0, NULL, fs_prohibit_write},
 	{"allow-write", 0, NULL, fs_allow_write},
 	{"exit", 0, NULL, ctrl_exit}

src/fs.c

@@ -2,6 +2,7 @@
 #include <string.h>
 #include <fcntl.h>
 #include <sys/stat.h>
+#include <stdlib.h>
 
 #include "print.h"
 #include "fs.h"
@@ -10,6 +11,7 @@
 
 const static int BLOCK_ADDRESSES_PER_INODE = (FS_BLOCK_SIZE-sizeof(int)*3) / sizeof(int);
 const static int BLOCK_ADDRESSES_PER_INODE_EXTENSION = (FS_BLOCK_SIZE-sizeof(int)) / sizeof(int);
+const static int DIRECTORY_RECORDS_PER_BLOCK = FS_BLOCK_SIZE / sizeof(struct fs_directory_record);
 
 
 static char used_file_path[FS_MAX_DEVICE_FILE_NAME_LEN+1];
@@ -19,6 +21,7 @@ static int write_permitted;
 static char fs_cwd[FS_MAX_PATH_LEN+1];
 static struct fs_header fsh_cache;
 static char fs_bitmap_cache[FS_BLOCK_SIZE * FS_MAX_BITMAP_SIZE];
+static unsigned int fs_cwd_inode_ptr;
 
 
 static int read_block(unsigned int block_no, void *data)
@@ -136,6 +139,75 @@ static unsigned int find_free_block(void)
 	return 0;
 }
 
+static unsigned int find_free_inode_ptr(void)
+{
+	unsigned int i = 1;  // inode0 always points to root dir, so can't be free
+
+	// search fs_header
+	for ( ; i < BLOCK_ADDRESSES_PER_INODE; i++) {
+		if (fsh_cache.inode_ptrs[i] == 0) {
+			if (i < fsh_cache.max_inode_count) {
+				return i;
+			} else {
+				return 0;
+			}
+		}
+	}
+
+	// search fs_header_extensions
+	struct fs_header_extension ext;
+	unsigned int next_extension = fsh_cache.next_extension;
+
+	while (next_extension) {
+		read_block(next_extension, (void *) &ext);
+		next_extension = ext.next_extension;
+
+		for (int j = 0; j < BLOCK_ADDRESSES_PER_INODE_EXTENSION; j++, i++) {
+			if (ext.inode_ptrs[j] == 0) {
+				if (i < fsh_cache.max_inode_count) {
+					return i;
+				} else {
+					return 0;
+				}
+			}
+		}
+	}
+
+	if (i < fsh_cache.max_inode_count) {
+		return i;
+	} else {
+		return 0;
+	}
+}
+
+static unsigned int read_inode_ptr(unsigned int inode_ptr)
+{
+	if ((inode_ptr / BLOCK_ADDRESSES_PER_INODE) == 0) {
+		// inode_ptr is in the fs_header
+		struct fs_header fsh;
+		int read_result = read_block(0, &fsh);
+		if (FS_BLOCK_SIZE != read_result) {
+			if (read_result < 0) {
+				pr_err("failed to read fs header from device '%s'\n", used_file_path);
+			} else {
+				pr_err("failed to read full header from device (read %d/%d bytes)\n", read_result, FS_BLOCK_SIZE);
+			}
+
+			return 0;
+		}
+
+		return fsh.inode_ptrs[inode_ptr];
+	} else {
+		pr_err("inode_ptr %d is in fs_header_extension, reading is not implemented\n", inode_ptr);
+		return 0;
+		// TODO: find block with relevant inode_ptr
+		/*
+		unsigned int relevant_block_index = ((free_block_index - BLOCK_ADDRESSES_PER_INODE) / BLOCK_ADDRESSES_PER_INODE_EXTENSION) + 1;
+		unsigned int relevant_block_record_offset = (free_block_index - BLOCK_ADDRESSES_PER_INODE) % BLOCK_ADDRESSES_PER_INODE_EXTENSION;
+		*/
+	}
+}
+
 static void write_inode_ptr(unsigned int inode_ptr, unsigned int block_ptr)
 {
 	if ((inode_ptr / BLOCK_ADDRESSES_PER_INODE) == 0) {
@@ -167,6 +239,7 @@ static void write_inode_ptr(unsigned int inode_ptr, unsigned int block_ptr)
 
 		pr("Updated inode ptr %d -> %d\n", inode_ptr, block_ptr);
 	} else {
+		pr_err("inode_ptr %d is in fs_header_extension, writing is not implemented\n", inode_ptr);
 		// TODO: find block with relevant inode_ptr, extend fs_header if needed
 		/*
 		unsigned int relevant_block_index = ((free_block_index - BLOCK_ADDRESSES_PER_INODE) / BLOCK_ADDRESSES_PER_INODE_EXTENSION) + 1;
@@ -214,9 +287,314 @@ int fs_prohibit_write(void *d)
 	return 0;
 }
 
+static struct fs_directory_record *fs_read_dir(unsigned int fs_inode_ptr)
+{
+	unsigned int inode_block_no = read_inode_ptr(fs_inode_ptr);
+	struct fs_inode dir_inode;
+	read_block(inode_block_no, &dir_inode);
+
+	if (dir_inode.size == 0) {
+		pr("directory is empty\n");
+		return NULL;
+	}
+
+	struct fs_directory_record *recs = malloc(fsh_cache.max_inode_count * sizeof(struct fs_directory_record));
+	memset(recs, 0, fsh_cache.max_inode_count * sizeof(struct fs_directory_record));
+
+	// read block portion from dir_inode
+	for (int i = 0; (i*DIRECTORY_RECORDS_PER_BLOCK < dir_inode.size) && (i < BLOCK_ADDRESSES_PER_INODE); i++) {
+		if (dir_inode.blocks[i]) {
+			read_block(dir_inode.blocks[i], &(recs[i*DIRECTORY_RECORDS_PER_BLOCK]));
+		}
+	}
+
+	// read block portions from inode extensions
+	// TODO
+
+	return recs;
+}
+
+static int fs_find_free_directory_record(unsigned int dir_inode_ptr)
+{
+	struct fs_directory_record *recs = fs_read_dir(dir_inode_ptr);
+	if (!recs) {
+		return 0;
+	}
+
+	for (unsigned int i = 0; i < fsh_cache.max_inode_count; i++) {
+		if (!recs[i].inode_no) {
+			free(recs);
+			return i;
+		}
+	}
+
+	free(recs);
+	return -1;
+}
+
+static int fs_add_fname_to_directory(unsigned int dir_inode_ptr, unsigned int target_inode_ptr, char *fname)
+{
+	int new_directory_record_index = fs_find_free_directory_record(dir_inode_ptr);
+	if (new_directory_record_index < 0) {
+		pr_err("no free inode pointer found\n");
+		return -1;
+	}
+
+	if (new_directory_record_index < DIRECTORY_RECORDS_PER_BLOCK * BLOCK_ADDRESSES_PER_INODE) {
+		// record is located in base inode, writing to it
+		int block_no = new_directory_record_index / DIRECTORY_RECORDS_PER_BLOCK;
+		int block_offset = new_directory_record_index % DIRECTORY_RECORDS_PER_BLOCK;
+
+		struct fs_inode dir_inode;
+		read_block(read_inode_ptr(dir_inode_ptr), (void *) &dir_inode);
+
+		if (dir_inode.blocks[block_no] == 0) {
+			// allocate new block
+			unsigned int new_block = find_free_block();
+			if (new_block == 0) {
+				pr_err("failed to allocate block to extend directory (inode_ptr=%d)\n", dir_inode_ptr);
+				return -1;
+			} else {
+				pr("Allocated new physical block %d for inode_ptr=%d (inode=%d, inner_block_no=%d)\n",
+						new_block, read_inode_ptr(dir_inode_ptr), block_no);
+			}
+
+			char zero_data[FS_BLOCK_SIZE] = {};
+			memset(zero_data, 0, FS_BLOCK_SIZE);
+			write_block(new_block, &zero_data);
+
+			mark_used(new_block);
+
+			dir_inode.blocks[block_no] = new_block;
+			if (dir_inode.size <= block_no * FS_BLOCK_SIZE) {
+				pr("Updated directory size at inode_ptr=%d: %d -> %d\n",
+						dir_inode_ptr, dir_inode.size, (block_no + 1) * FS_BLOCK_SIZE);
+				dir_inode.size = (block_no + 1) * FS_BLOCK_SIZE;
+				write_block(read_inode_ptr(dir_inode_ptr), (void *) &dir_inode);
+			}
+		}
+
+		struct fs_directory_record recs[DIRECTORY_RECORDS_PER_BLOCK];
+		read_block(dir_inode.blocks[block_no], (void *) &recs);
+
+		strcpy(recs[block_offset].fname, fname);
+		recs[block_offset].inode_no = target_inode_ptr;
+
+		write_block(dir_inode.blocks[block_no], (void *) &recs);
+
+		pr("Written new directory record #%d for file '%s' (-> %d) in inode_ptr=%d\n",
+				new_directory_record_index, fname, target_inode_ptr, dir_inode_ptr);
+
+		return 0;
+	} else {
+		// record is located in inode extension
+		// TODO
+	}
+
+	// I don't remember what was this, but this function shouldn't need it
+
+	// write new record
+	//unsigned int inode_block_no = read_inode_ptr(fs_inode_ptr);
+}
+
 int fs_create(void *d)
 {
-	pr("[mock] Regular file '%s' created\n", *((char **) d));
+	char *fname = *((char **) d);
+	int fname_len = strlen(fname);
+
+	if (fname_len > 59) {
+		pr_err("filename too long (%d > %d)\n", fname_len, 59);
+		return 0;
+	}
+
+	pr("Creating regular file '%s'\n", fname);
+
+	int inode_block_no = find_free_block();
+	if (!inode_block_no) {
+		pr_err("no free blocks available to save file inode\n");
+		return 0;
+	}
+
+	// write new file inode
+	struct fs_inode newf = {};
+	newf.ftype = REGULAR;
+	newf.ref_count = 1;
+	newf.size = 0;
+
+	{
+		int bytes_written = write_block(inode_block_no, (void *) &newf);
+
+		if (bytes_written < 0) {
+			pr_err("failed to write inode block to device '%s'\n", used_file_path);
+			return 0;
+		} else if (bytes_written < FS_BLOCK_SIZE) {
+			pr_err("failed to write full inode block to device '%s' (written %d/%d bytes)\n",
+					used_file_path, bytes_written, FS_BLOCK_SIZE);
+			return 0;
+		} else {
+			pr("Written inode block to device '%s'\n", used_file_path);
+		}
+
+		mark_used(inode_block_no);
+	}
+
+	// allocate and write inode pointer for new inode
+	unsigned int inode_ptr_index = find_free_inode_ptr();
+	if (!inode_ptr_index) {
+		pr_err("no free inode ptr found\n");
+		return 0;
+	}
+	write_inode_ptr(inode_ptr_index, inode_block_no);
+
+	// add filename to current directory inode
+	fs_add_fname_to_directory(fs_cwd_inode_ptr, inode_ptr_index, fname);
+
+	return 0;
+}
+
+int fs_ln(void *d) {
+	if (used_file_fd <= 0) {
+		pr_err("no storage device\n");
+		return 0;
+	}
+
+	char *existing_fname = ((char **) d)[0];
+	char *new_fname = ((char **)d)[1];
+	int new_fname_len = strlen(new_fname);
+
+	if (new_fname_len > 59) {
+		pr_err("new filename too long (%d > 59)\n", new_fname_len);
+		return 0;
+	}
+
+	pr("Making hard link '%s' -> '%s'\n", new_fname, existing_fname);
+
+	// find original file name
+	unsigned int original_inode_ptr = 0;
+
+	int dir_inode = read_inode_ptr(fs_cwd_inode_ptr);
+
+	struct fs_inode dir;
+	read_block(dir_inode, (void *) &dir);
+
+	// list entries from base inode
+	for (int i = 0; i < BLOCK_ADDRESSES_PER_INODE; i++) {
+		struct fs_directory_record recs[DIRECTORY_RECORDS_PER_BLOCK];
+
+		if (dir.blocks[i]) {
+			read_block(dir.blocks[i], (void *) &recs);
+
+			for (int k = 0; k < DIRECTORY_RECORDS_PER_BLOCK; k++) {
+				if (!recs[k].inode_no)
+					continue;
+
+				if (!strcmp(existing_fname, recs[k].fname)) {
+					original_inode_ptr = recs[k].inode_no;
+					goto original_inode_ptr_found;
+				}
+			}
+		}
+	}
+
+	pr_err("no such file '%d'\n", existing_fname);
+	return 0;
+
+original_inode_ptr_found:
+	pr("Original inode_ptr found (%d)\n", original_inode_ptr);
+
+	// register new filename with the same inode_ptr
+	if (fs_add_fname_to_directory(fs_cwd_inode_ptr, original_inode_ptr, new_fname) < 0) {
+		pr_err("failed to register filename in directory '%s'\n", fs_cwd_inode_ptr);
+		return 0;
+	} else {
+		pr("Registered new filename in directory '%s'\n", fs_cwd_inode_ptr);
+	}
+
+	// update ref_count in file inode
+	struct fs_inode f;
+	read_block(read_inode_ptr(original_inode_ptr), (void *) &f);
+	f.ref_count++;
+	write_block(read_inode_ptr(original_inode_ptr), (void *) &f);
+
+	pr("Updated inode ref_count (%d -> %d)\n", f.ref_count-1, f.ref_count);
+}
+
+int fs_ls(void *d) {
+	if (used_file_fd <= 0) {
+		pr_err("no storage device\n");
+		return 0;
+	}
+
+	int dir_inode = read_inode_ptr(fs_cwd_inode_ptr);
+
+	struct fs_inode dir;
+	read_block(dir_inode, (void *) &dir);
+
+	// list entries from base inode
+	for (int i = 0; i < BLOCK_ADDRESSES_PER_INODE; i++) {
+		struct fs_directory_record recs[DIRECTORY_RECORDS_PER_BLOCK];
+
+		if (dir.blocks[i]) {
+			read_block(dir.blocks[i], (void *) &recs);
+
+			for (int k = 0; k < DIRECTORY_RECORDS_PER_BLOCK; k++) {
+				if (!recs[k].inode_no)
+					continue;
+
+				pr_stdout("%s\n", recs[k].fname);
+			}
+		}
+	}
+
+	// list entries from inode extension
+	// TODO
+
+	return 0;
+}
+
+int fs_la(void *d) {
+	if (used_file_fd <= 0) {
+		pr_err("no storage device\n");
+		return 0;
+	}
+
+	int dir_inode = read_inode_ptr(fs_cwd_inode_ptr);
+
+	struct fs_inode dir;
+	read_block(dir_inode, (void *) &dir);
+
+	pr_stdout("directory size: %d\n", dir.size);
+
+	// list entries from base inode
+	for (int i = 0; i < BLOCK_ADDRESSES_PER_INODE; i++) {
+		struct fs_directory_record recs[DIRECTORY_RECORDS_PER_BLOCK];
+
+		if (dir.blocks[i]) {
+			read_block(dir.blocks[i], (void *) &recs);
+
+			for (int k = 0; k < DIRECTORY_RECORDS_PER_BLOCK; k++) {
+				if (!recs[k].inode_no)
+					continue;
+
+				struct fs_inode f_inode;
+				read_block(read_inode_ptr(recs[k].inode_no), (void *) &f_inode);
+
+				if (f_inode.ftype == DIRECTORY) {
+					pr_stdout(COLOR_BLUE "%s" COLOR_RESET
+							"(inode_ptr=%d -> inode=%d, ref_count=%d, size=%d, type=dir)\n",
+							recs[k].fname, recs[k].inode_no, read_inode_ptr(recs[k].inode_no),
+							f_inode.ref_count, f_inode.size);
+				} else {
+					pr_stdout("%s (inode_ptr=%d -> inode=%d, ref_count=%d, size=%d, type=reg)\n",
+							recs[k].fname, recs[k].inode_no, read_inode_ptr(recs[k].inode_no),
+							f_inode.ref_count, f_inode.size);
+				}
+			}
+		}
+	}
+
+	// list entries from inode extension
+	// TODO
 
 	return 0;
 }
@@ -304,6 +682,8 @@ int fs_use(void *d)
 
 		char *root_dir_path = "/";
 		fs_chdir((void *) &root_dir_path);
+
+		fs_cwd_inode_ptr = 0;
 	}
 
 	return 0;
@@ -439,8 +819,13 @@ finish_current_block:
 	// inode0 -> root_dir_block
 	write_inode_ptr(0, free_block_index);
 
+	// update fsh cache
+	memcpy(&fsh_cache, &fsh, FS_BLOCK_SIZE);
+
 	char *root_dir_path = "/";
 	fs_chdir((void *) &root_dir_path);
 
+	fs_cwd_inode_ptr = 0;
+
 	return 0;
 }