Unique location in the filesystem. More...

Data Structures
struct	path_t
	Path structure. More...

struct	pathname_t
	Pathname structure. More...

Macros
#define	PATH_DEFER(path) __attribute__((cleanup(path_defer_cleanup))) path_t* CONCAT(i, __COUNTER__) = (path)
	Defer path put.

#define	PATH_VALID_CHAR(ch) (strchr("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-. ()[]{}~!@#$%^&?',;=+", (ch)))
	Check if a char is valid.

#define	PATH_HANDLE_DOTDOT_MAX_ITER 1000
	Maximum iterations to handle `..` in a path.

#define	PATHNAME_IS_VALID(pathname) ((pathname) != NULL && (pathname)->isValid)
	Check if a pathname is valid.

#define	PATHNAME(string)
	Helper to create a pathname.

#define	PATH_EMPTY
	Helper to create an empty path.

#define	PATH_CREATE(inMount, inDentry)
	Helper to create a path.

Enumerations
enum	path_flags_t { PATH_NONE = 0 , PATH_NONBLOCK = 1 << 0 , PATH_APPEND = 1 << 1 , PATH_CREATE = 1 << 2 , PATH_EXCLUSIVE = 1 << 3 , PATH_TRUNCATE = 1 << 4 , PATH_DIRECTORY = 1 << 5 , PATH_RECURSIVE = 1 << 6 , PATH_FLAGS_AMOUNT = 7 }
	Path flags. More...

enum	walk_flags_t { WALK_NONE = 0 , WALK_NEGATIVE_IS_OK = 1 << 0 }
	Flags for walking a path. More...

Functions
void	path_flags_init (void)
	Initialize path flags resolution.

uint64_t	pathname_init (pathname_t pathname, const char string)
	Initialize a pathname.

void	path_set (path_t path, mount_t mount, dentry_t *dentry)
	Set a path.

void	path_copy (path_t dest, const path_t src)
	Copy a path.

void	path_put (path_t *path)
	Put a path.

uint64_t	path_walk_single_step (path_t outPath, const path_t parent, const char name, walk_flags_t flags, namespace_t ns)
	Traverse a single component from a parent path.

uint64_t	path_walk (path_t outPath, const pathname_t pathname, const path_t start, walk_flags_t flags, namespace_t ns)
	Traverse a pathname from a specified starting path.

uint64_t	path_walk_parent (path_t outPath, const pathname_t pathname, const path_t start, char outLastName, walk_flags_t flags, namespace_t *ns)
	Traverse a pathname to its parent and get the last component name.

uint64_t	path_to_name (const path_t path, pathname_t pathname)
	Convert a path to a pathname.

static void	path_defer_cleanup (path_t **path)

Detailed Description

Unique location in the filesystem.

A path is a single unique location in the filesystem hierarchy. It consists of a mount and a dentry. The mount is the filesystem that the path is in and the dentry is the actual location in that filesystem.

Note how just a dentry is not enough to uniquely identify a location in the filesystem, this is because of mountpoints. A dentry can exist in multiple places if its part of a filesystem that has been mounted in multiple places.

Flags

Paths can have flags appended to them which is how we handle general file flags. Each flag starts with : and the same path can contain multiples of different or the same flag, for example /path/to/file:create:create:nonblock.

Included is a list of all available flags:

nonblock: Open the file in non-blocking mode.
append: Any data written to the file will be appended to the end.
create: Create the file if it does not exist.
excl: Will cause the open to fail if the file already exists. Must be used with create.
trunc: Truncate the file to zero length if it already exists.
dir: Allow opening directories.
recur: Behaviour differs, but allows for recursive operations, for example when used with remove it will remove directories and their children recursively.

Macro Definition Documentation

◆ PATH_CREATE

#define PATH_CREATE	(	inMount,
		inDentry
	)

Value:

    (path_t) \
    { \
        .mount = REF(inMount), .dentry = REF(inDentry), \
    }

Helper to create a path.

Parameters

inMount	The mount of the path.
inDentry	The dentry of the path.

Returns: The created path.

Definition at line 195 of file path.h.

◆ PATH_DEFER

#define PATH_DEFER ( path ) __attribute__((cleanup(path_defer_cleanup))) path_t* CONCAT(i, __COUNTER__) = (path)

Defer path put.

This macro will call path_put() on the given path when it goes out of scope.

Parameters

path	The path to defer.

Definition at line 53 of file path.h.

◆ PATH_EMPTY

#define PATH_EMPTY

Value:

    (path_t) \
    { \
        .mount = NULL, .dentry = NULL \
    }

Helper to create an empty path.

Its important to always use this as some functions, for example path_copy(), will deref the existing mount and dentry in the path.

Returns: An empty path.

Definition at line 182 of file path.h.

◆ PATH_HANDLE_DOTDOT_MAX_ITER

#define PATH_HANDLE_DOTDOT_MAX_ITER 1000

Maximum iterations to handle .. in a path.

This is to prevent infinite loops in case of a corrupted filesystem.

Definition at line 74 of file path.h.

◆ PATH_VALID_CHAR

#define PATH_VALID_CHAR ( ch ) (strchr("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-. ()[]{}~!@#$%^&?',;=+", (ch)))

Check if a char is valid.

A valid char is one of the following ‘abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-. ()[]{}~!#$%^&?’,;=+`.

TODO: Replace with array lookup.

Parameters

ch	The char to check.

Returns: true if the char is valid, false otherwise.

Definition at line 66 of file path.h.

◆ PATHNAME

#define PATHNAME ( string )

Value:

    ({ \
        pathname_t* pathname = alloca(sizeof(pathname_t)); \
        pathname_init(pathname, string); \
        pathname; \
    })

Helper to create a pathname.

This macro will create a pathname on the stack and initialize it with the given string.

This is also the reason we have the isValid flag in the pathname_t structure, to be able to check if this macro failed without having to return an error code, streamlining the code a bit.

Parameters

string The string to initialize the pathname with.

Returns: The initialized pathname.

Definition at line 156 of file path.h.

◆ PATHNAME_IS_VALID

#define PATHNAME_IS_VALID ( pathname ) ((pathname) != NULL && (pathname)->isValid)

Check if a pathname is valid.

A valid pathname is not NULL and has its isValid flag set to true.

This flag is set in pathname_init().

Parameters

pathname The pathname to check.

Returns: true if the pathname is valid, false otherwise.

Definition at line 143 of file path.h.

Enumeration Type Documentation

◆ path_flags_t

enum path_flags_t

Path flags.

Used to store parsed flags.

Enumerator
PATH_NONE
PATH_NONBLOCK
PATH_APPEND
PATH_CREATE
PATH_EXCLUSIVE
PATH_TRUNCATE
PATH_DIRECTORY
PATH_RECURSIVE
PATH_FLAGS_AMOUNT

Definition at line 82 of file path.h.

◆ walk_flags_t

enum walk_flags_t

Flags for walking a path.

Enumerator
WALK_NONE	No flags.
WALK_NEGATIVE_IS_OK	If a negative dentry is ok, if not specified then it is considered an error.

Definition at line 99 of file path.h.

Function Documentation

◆ path_copy()

void path_copy	(	path_t *	dest,
		const path_t *	src
	)

Copy a path.

Will deref the existing mount and dentry in the destination path if they are not NULL.

Parameters

dest	The destination path.
src	The source path.

Definition at line 232 of file path.c.

References path_t::dentry, DEREF, path_t::mount, NULL, and REF.

Referenced by file_new(), namespace_traverse_mount(), path_to_name(), path_walk(), path_walk_parent(), path_walk_single_step(), vfs_create(), vfs_ctx_get_cwd(), vfs_ctx_init(), vfs_ctx_set_cwd(), vfs_open_lookup(), and vfs_walk_parent_and_child().

◆ path_defer_cleanup()

static void path_defer_cleanup ( path_t ** path )

inlinestatic

Definition at line 282 of file path.h.

References NULL, and path_put().

◆ path_flags_init()

void path_flags_init ( void )

Initialize path flags resolution.

Definition at line 66 of file path.c.

References ERR, flagEntries, flagMap, flagShortMap, map_entry_init(), map_init(), map_insert(), map_key_buffer(), map_key_string(), NULL, panic(), and PATH_FLAGS_AMOUNT.

Referenced by vfs_init().

◆ path_put()

void path_put ( path_t * path )

Put a path.

Will deref the mount and dentry in the path if they are not NULL.

Parameters

path	The path to put.

Definition at line 257 of file path.c.

References path_t::dentry, DEREF, path_t::mount, and NULL.

Referenced by file_free(), path_defer_cleanup(), path_walk(), process_dir_init(), process_init(), socket_new(), SYSCALL_DEFINE(), sysfs_mount_new(), vfs_ctx_deinit(), and vfs_ctx_set_cwd().

◆ path_set()

void path_set	(	path_t *	path,
		mount_t *	mount,
		dentry_t *	dentry
	)

Set a path.

Will deref the existing mount and dentry in the path if they are not NULL.

Parameters

path	The path to set.
mount	The mount to set.
dentry	The dentry to set.

Definition at line 207 of file path.c.

References path_t::dentry, DEREF, path_t::mount, mount, NULL, and REF.

Referenced by namespace_get_root_path(), namespace_traverse_mount(), path_to_name(), path_walk_single_step(), socket_family_get_dir(), and sysfs_mount_new().

◆ path_to_name()

uint64_t path_to_name	(	const path_t *	path,
		pathname_t *	pathname
	)

Convert a path to a pathname.

The resulting pathname will be absolute.

Parameters

path	The path to convert.
pathname	The output pathname.

Returns: On success, 0. On failure, ERR and errno is set.

Definition at line 583 of file path.c.

References path_t::dentry, DENTRY_IS_ROOT, EINVAL, ENAMETOOLONG, ERR, errno, pathname_t::flags, pathname_t::isValid, MAX_NAME, MAX_PATH, memcpy(), memmove(), memset(), path_t::mount, mount_t::mountpoint, dentry_t::name, NULL, dentry_t::parent, mount_t::parent, path_copy(), PATH_DEFER, PATH_EMPTY, PATH_NONE, path_set(), pathname_t::string, and strnlen_s().

Referenced by process_cwd_read().

◆ path_walk()

uint64_t path_walk	(	path_t *	outPath,
		const pathname_t *	pathname,
		const path_t *	start,
		walk_flags_t	flags,
		namespace_t *	ns
	)

Traverse a pathname from a specified starting path.

Parameters

outPath	The output path.
pathname	The patname to traverse to.
start	The path to start at if the pathname is relative.
flags	Flags for the path walk.
ns	The namespace to access mountpoints.

Returns: On success, 0. On failure, ERR and errno is set.

Definition at line 376 of file path.c.

References assert, atomic_load, path_t::dentry, DENTRY_NEGATIVE, EBADFLAG, EINVAL, ENAMETOOLONG, ENOENT, ERR, errno, MAX_NAME, memcpy(), path_t::mount, dentry_t::mountCount, namespace_get_root_path(), namespace_traverse_mount(), next, NULL, path_copy(), PATH_DEFER, PATH_EMPTY, path_handle_dotdot(), path_put(), PATH_VALID_CHAR, path_walk_single_step(), PATHNAME_IS_VALID, start(), strcmp(), pathname_t::string, and WALK_NEGATIVE_IS_OK.

Referenced by path_walk_parent(), and vfs_walk().

◆ path_walk_parent()

uint64_t path_walk_parent	(	path_t *	outPath,
		const pathname_t *	pathname,
		const path_t *	start,
		char *	outLastName,
		walk_flags_t	flags,
		namespace_t *	ns
	)

Traverse a pathname to its parent and get the last component name.

Parameters

outPath	The output parent path.
pathname	The pathname to traverse.
start	The path to start at if the pathname is relative.
outLastName	The output last component name.
flags	Flags for the path walk.
ns	The namespace to access mountpoints.

Returns: On success, 0. On failure, ERR and errno is set.

Definition at line 511 of file path.c.

References EINVAL, ENOENT, ERR, errno, MAX_NAME, MAX_PATH, memset(), NULL, path_copy(), path_walk(), pathname_init(), PATHNAME_IS_VALID, start(), strcmp(), pathname_t::string, strncpy(), strnlen_s(), and strrchr().

Referenced by vfs_walk_parent().

◆ path_walk_single_step()

uint64_t path_walk_single_step	(	path_t *	outPath,
		const path_t *	parent,
		const char *	name,
		walk_flags_t	flags,
		namespace_t *	ns
	)

Traverse a single component from a parent path.

Parameters

outPath	The output path.
parent	The parent path.
name	The name of the child dentry.
flags	Flags for the path walk.
ns	The namespace to access mountpoints.

Returns: On success, 0. On failure, ERR and errno is set.

Definition at line 329 of file path.c.

References atomic_load, path_t::dentry, DENTRY_NEGATIVE, DEREF_DEFER, EINVAL, ENOENT, ERR, errno, path_t::mount, dentry_t::mountCount, namespace_traverse_mount(), next, NULL, path_copy(), PATH_DEFER, PATH_EMPTY, path_set(), vfs_get_or_lookup_dentry(), vfs_is_name_valid(), and WALK_NEGATIVE_IS_OK.

Referenced by path_walk(), and vfs_walk_parent_and_child().

◆ pathname_init()

uint64_t pathname_init	(	pathname_t *	pathname,
		const char *	string
	)

Initialize a pathname.

If the string is invalid, it will error and set pathname->isValid to false.

Parameters

pathname	The pathname to initialize.
string	The string to initialize the pathname with.

Returns: On success, 0. On failure, ERR and errno is set.

Definition at line 100 of file path.c.

References EBADFLAG, EINVAL, ENAMETOOLONG, ERR, errno, path_flag_entry_t::flag, pathname_t::flags, isalnum(), pathname_t::isValid, MAX_NAME, MAX_PATH, memset(), NULL, path_flags_get(), PATH_NONE, PATH_VALID_CHAR, pathname_t::string, and strnlen_s().

Referenced by loader_spawn(), path_walk_parent(), and thread_copy_from_user_pathname().

Data Structures

Macros

Enumerations

Functions

Detailed Description

Flags

Macro Definition Documentation

◆ PATH_CREATE

◆ PATH_DEFER

◆ PATH_EMPTY

◆ PATH_HANDLE_DOTDOT_MAX_ITER

◆ PATH_VALID_CHAR

◆ PATHNAME

◆ PATHNAME_IS_VALID

Enumeration Type Documentation

◆ path_flags_t

◆ walk_flags_t

Function Documentation

◆ path_copy()

◆ path_defer_cleanup()

◆ path_flags_init()

◆ path_put()

◆ path_set()

◆ path_to_name()

◆ path_walk()

◆ path_walk_parent()

◆ path_walk_single_step()

◆ pathname_init()