hasslesstech/spz-lab4
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base: hasslesstech:049405989b684ebf5c4c5ae4324b6de5488039c5
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hasslesstech:master
hasslesstech:lab5
hasslesstech:lab4
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compare: hasslesstech:552e574cde247ee0d36b54d93f961c4346e5d38f
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hasslesstech:master
hasslesstech:lab5
hasslesstech:lab4

No commits in common. "049405989b684ebf5c4c5ae4324b6de5488039c5" and "552e574cde247ee0d36b54d93f961c4346e5d38f" have entirely different histories.
049405989b ... 552e574cde

2 changed files with 52 additions and 209 deletions
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4
config.h
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@ -26,8 +26,8 @@
#define FS_MAX_PATH_LEN 512 #define FS_MAX_PATH_LEN 512
#define FS_MAX_OPEN_FD 32 #define FS_MAX_OPEN_FD 32
#define FS_MAX_FNAME_LEN 11 #define FS_MAX_FNAME_LEN 11
#define FS_MAX_DIRECTORY_DEPTH 2048 #define FS_MAX_DIRECTORY_DEPTH 512
#define FS_MAX_SYMLINK_FOLLOWS 1024 #define FS_MAX_SYMLINK_FOLLOWING_DEPTH 1024
#endif #endif

257
src/fs.c
View File

@ -24,7 +24,6 @@ static unsigned int fs_cwd_inode_ptr;
static struct fs_file_description fs_file_descriptions[FS_MAX_OPEN_FD]; static struct fs_file_description fs_file_descriptions[FS_MAX_OPEN_FD];
static int extract_basename(char *path, char *name); static int extract_basename(char *path, char *name);
static int read_symlink(int symlink_inode_ptr, char *path);
static int read_block(unsigned int block_no, void *data) static int read_block(unsigned int block_no, void *data)
@ -908,21 +907,18 @@ fs_remove_fname_from_directory_finish:
return 0; return 0;
} }
static void resolve_path(struct resolved_path * const rp, const char * const original_path, const unsigned int params) static void resolve_path(struct resolved_path *rp, char *path, unsigned int params)
{ {
rp->parent_inode_ptr = -1; rp->parent_inode_ptr = -1;
rp->target_inode_ptr = -1; rp->target_inode_ptr = -1;
int path_len = strlen(original_path); int path_len = strlen(path);
if (!path_len) { if (!path_len) {
pr_err("no path specified\n"); pr_err("no path specified\n");
return; return;
} }
char path[FS_MAX_PATH_LEN+1];
strcpy(path, original_path);
if (!strcmp(path, "/")) { if (!strcmp(path, "/")) {
rp->parent_inode_ptr = 0; rp->parent_inode_ptr = 0;
rp->target_inode_ptr = 0; rp->target_inode_ptr = 0;
@ -935,8 +931,6 @@ static void resolve_path(struct resolved_path * const rp, const char * const ori
int current_inode_ptr; int current_inode_ptr;
int i; int i;
unsigned int symlinks_followed = 0;
if (path[0] == '/') { if (path[0] == '/') {
current_inode_ptr = 0; current_inode_ptr = 0;
rp->parent_inode_ptr = 0; rp->parent_inode_ptr = 0;
@ -956,149 +950,65 @@ static void resolve_path(struct resolved_path * const rp, const char * const ori
if (path[i] != '/') { if (path[i] != '/') {
next_fname[next_fname_ptr] = path[i]; next_fname[next_fname_ptr] = path[i];
next_fname_ptr++; next_fname_ptr++;
continue;
} }
if ((path[i] != '/') && (i+1 < path_len)) // path[i] == '/', trying to change current directory
continue;
if (!next_fname_ptr) if (!next_fname_ptr)
continue; continue;
if (i+1 == path_len)
continue;
{
int res = find_fname_in_directory(current_inode_ptr, next_fname);
if (res < 0) {
pr_warn("directory '%s' does not exist\n", next_fname);
rp->parent_inode_ptr = -1;
break;
}
{
struct fs_inode d;
read_block(read_inode_ptr(res), &d);
if (d.ftype == REGULAR) {
pr_warn("'%s' is a regular file\n", next_fname);
rp->parent_inode_ptr = -1;
break;
}
}
pr("Found directory '%s'\n", next_fname);
current_inode_ptr = res;
rp->parent_inode_ptr = res;
}
next_fname_ptr = 0;
strcpy(current_fname, next_fname);
memset(next_fname, 0, FS_MAX_FNAME_LEN);
}
if (rp->parent_inode_ptr < 0) {
rp->target_inode_ptr = -1;
return;
}
strcpy(rp->parent_fname, current_fname);
{
int res = find_fname_in_directory(current_inode_ptr, next_fname); int res = find_fname_in_directory(current_inode_ptr, next_fname);
if (res < 0) { if (res < 0) {
if (i+1 < path_len) { pr_warn("target fname '%s' does not exist\n", next_fname);
pr_warn("parent '%s' does not exist\n", next_fname);
rp->parent_inode_ptr = -1;
}
rp->target_inode_ptr = -1; rp->target_inode_ptr = -1;
break; } else {
rp->target_inode_ptr = res;
strcpy(rp->target_fname, next_fname);
} }
struct fs_inode d;
read_block(read_inode_ptr(res), &d);
if (d.ftype == SYMLINK) {
if (i+1 < path_len) {
symlinks_followed++;
if (symlinks_followed > FS_MAX_SYMLINK_FOLLOWS) {
pr_err("too many symlink follows\n");
rp->parent_inode_ptr = -1;
rp->target_inode_ptr = -1;
break;
}
char symlink_path[FS_MAX_PATH_LEN+1];
int symlink_path_len = read_symlink(res, symlink_path);
if (symlink_path_len < 0) {
pr_warn("broken symlink\n");
rp->parent_inode_ptr = -1;
rp->target_inode_ptr = -1;
break;
}
if (symlink_path[0] == '/') {
memmove(&(path[symlink_path_len]), &(path[i+1]), path_len-i-1);
strcpy(path, &(symlink_path[1]));
path[symlink_path_len-1] = '/';
path_len = symlink_path_len + path_len - i - 1;
i = -1;
next_fname_ptr = 0;
strcpy(current_fname, "/");
memset(next_fname, 0, FS_MAX_FNAME_LEN);
} else {
memmove(&(path[symlink_path_len+1]), &(path[i+1]), path_len-i-1);
strcpy(path, symlink_path);
path[symlink_path_len] = '/';
path_len = symlink_path_len + path_len - i;
i = -1;
next_fname_ptr = 0;
strcpy(current_fname, next_fname);
memset(next_fname, 0, FS_MAX_FNAME_LEN);
}
} else {
if (!(params & FOLLOW_LAST_SYMLINK)) {
rp->target_inode_ptr = res;
strcpy(rp->parent_fname, current_fname);
strcpy(rp->target_fname, next_fname);
break;
}
symlinks_followed++;
if (symlinks_followed > FS_MAX_SYMLINK_FOLLOWS) {
pr_err("too many symlink follows\n");
rp->parent_inode_ptr = -1;
rp->target_inode_ptr = -1;
break;
}
char symlink_path[FS_MAX_PATH_LEN+1];
int symlink_path_len = read_symlink(res, symlink_path);
if (symlink_path_len < 0) {
pr_warn("broken symlink\n");
rp->parent_inode_ptr = -1;
rp->target_inode_ptr = -1;
break;
}
if (!strcmp(symlink_path, "/")) {
rp->parent_inode_ptr = 0;
rp->target_inode_ptr = 0;
strcpy(rp->parent_fname, "/");
strcpy(rp->target_fname, "/");
break;
}
if (symlink_path[0] == '/') {
strcpy(path, &(symlink_path[1]));
path_len = symlink_path_len - 1;
i = -1;
next_fname_ptr = 0;
strcpy(current_fname, "/");
memset(next_fname, 0, FS_MAX_FNAME_LEN);
} else {
strcpy(path, symlink_path);
path_len = symlink_path_len;
i = -1;
next_fname_ptr = 0;
strcpy(current_fname, next_fname);
memset(next_fname, 0, FS_MAX_FNAME_LEN);
}
}
} else if (d.ftype == REGULAR) {
if (i+1 < path_len) {
pr_warn("'%s': regular file not in the end of a path\n", next_fname);
rp->parent_inode_ptr = -1;
rp->target_inode_ptr = -1;
break;
} else {
rp->target_inode_ptr = res;
strcpy(rp->parent_fname, current_fname);
strcpy(rp->target_fname, next_fname);
}
} else if (d.ftype == DIRECTORY) {
if (i+1 < path_len) {
pr("Found directory '%s'\n", next_fname);
current_inode_ptr = res;
rp->parent_inode_ptr = res;
next_fname_ptr = 0;
strcpy(current_fname, next_fname);
memset(next_fname, 0, FS_MAX_FNAME_LEN);
} else {
rp->target_inode_ptr = res;
strcpy(rp->parent_fname, current_fname);
strcpy(rp->target_fname, next_fname);
}
}
} }
return;
} }
@ -1721,73 +1631,6 @@ int fs_ln(void *d)
return 0; return 0;
} }
static int read_symlink(int symlink_inode_ptr, char *path)
{
struct fs_inode i;
read_block(read_inode_ptr(symlink_inode_ptr), &i);
path[0] = '\0';
int bytes_read = 0;
for (int j = 0; j < BLOCK_ADDRESSES_PER_INODE; j++) {
if (!i.blocks[j]) {
pr_err("inode size (%d) indicates existing block but it's address is absent in inode, symlink at inode_ptr=%d might be broken\n",
i.size, symlink_inode_ptr);
return -1;
}
char data[FS_BLOCK_SIZE];
read_block(i.blocks[j], data);
if (i.size - bytes_read < FS_BLOCK_SIZE) {
memcpy(&(path[bytes_read]), data, i.size - bytes_read);
bytes_read = i.size;
path[bytes_read] = '\0';
} else {
memcpy(&(path[bytes_read]), data, FS_BLOCK_SIZE);
bytes_read += FS_BLOCK_SIZE;
path[bytes_read] = '\0';
}
if (i.size == bytes_read)
goto finish_reading;
}
for (unsigned int next_ext = i.next_extension; ; ) {
struct fs_inode_extension ext;
read_block(next_ext, &ext);
for (int j = 0; j < BLOCK_ADDRESSES_PER_INODE_EXTENSION; j++) {
if (!ext.blocks[j]) {
pr_err("inode size (%d) indicates existing block but it's address is absent in inode extension, symlink at inode_ptr=%d might be broken\n",
i.size, symlink_inode_ptr);
return -1;
}
char data[FS_BLOCK_SIZE];
read_block(ext.blocks[j], data);
if (i.size - bytes_read < FS_BLOCK_SIZE) {
memcpy(&(path[bytes_read]), data, i.size - bytes_read);
bytes_read = i.size;
path[bytes_read] = '\0';
} else {
memcpy(&(path[bytes_read]), data, FS_BLOCK_SIZE);
bytes_read += FS_BLOCK_SIZE;
path[bytes_read] = '\0';
}
if (i.size == bytes_read)
goto finish_reading;
}
next_ext = ext.next_extension;
}
finish_reading:
return bytes_read;
}
int fs_symlink(void *d) int fs_symlink(void *d)
{ {
char *target_path = ((char **) d)[0]; char *target_path = ((char **) d)[0];