Big commit: Added symlink support to the kernel.

- added needed syscalls to access symlink support from userland
- implemented lstat(), symlink(), and readlink()
- added dev_t to ktypes.h (for now - should be in a public header anyway)
- added symlink support to the "ls" command (now calls lstat() and shows the
  link target with the -l option)
- changed the sys_read_stat() call to support symlinks, and updated files
  using that function (it gets an extra argument: bool traverseLink)


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@560 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/ksyscalls.h

@@ -22,8 +22,8 @@ enum {
 	SYSCALL_CREATE,
 	SYSCALL_UNLINK,
 	SYSCALL_RENAME,
-	SYSCALL_RSTAT,
-	SYSCALL_WSTAT,
+	SYSCALL_READ_STAT,
+	SYSCALL_WRITE_STAT,
 	SYSCALL_SYSTEM_TIME,
 	SYSCALL_SNOOZE,
 	SYSCALL_SEM_CREATE,
@@ -82,7 +82,7 @@ enum {
 	SYSCALL_SYSCTL,
 	SYSCALL_SOCKET,
 	SYSCALL_GETDTABLESIZE,
-	SYSCALL_FSTAT,
+	SYSCALL_FD_STAT,
 	SYSCALL_READ_DIR,
 	SYSCALL_REWIND_DIR,
 	SYSCALL_OPEN_DIR,
@@ -93,7 +93,9 @@ enum {
 	SYSCALL_OPEN_DIR_ENTRY_REF,
 	SYSCALL_OPEN_DIR_NODE_REF,
 	SYSCALL_CREATE_ENTRY_REF,
-	SYSCALL_CREATE_DIR_ENTRY_REF
+	SYSCALL_CREATE_DIR_ENTRY_REF,
+	SYSCALL_CREATE_SYMLINK,
+	SYSCALL_READ_LINK,
 };
 
 int syscall_dispatcher(unsigned long call_num, void *arg_buffer, uint64 *call_ret);

headers/private/kernel/ktypes.h

@@ -20,15 +20,14 @@ typedef int    team_id;
 typedef int    sem_id;
 typedef int    port_id;
 typedef int    image_id;
+typedef uint32 dev_t;
 typedef uint64 ino_t;
 typedef uint64 vnode_id;
 typedef uint32 fs_id;
 typedef uint16 nlink_t;
 typedef uint32 uid_t;
 typedef uint32 gid_t;
-
-/* compat with beos (was int32 on beos) */
-typedef int status_t;
+typedef int32 status_t;
 
 
 #ifdef  _OBOS_TIME_T_

headers/private/kernel/unistd.h

@@ -41,6 +41,9 @@ extern	 int optreset;
 
 extern   char **environ;
 
+int readlink(const char *path, char *buffer, size_t bufferSize);
+int symlink(const char *path, const char *toPath);
+
 off_t   lseek(int, off_t, int);
 ssize_t read(int, void *, size_t);
 ssize_t pread(int, void *, size_t, off_t);

headers/private/kernel/vfs.h

@@ -158,10 +158,12 @@ int sys_create_entry_ref(dev_t device, ino_t inode, const char *uname, int omode
 int sys_create(const char *path, int omode, int perms);
 int sys_create_dir_entry_ref(dev_t device, ino_t inode, const char *name, int perms);
 int sys_create_dir(const char *path, int perms);
-int sys_symlink(const char *path, const char *toPath);
+int sys_read_link(const char *path, char *buffer, size_t bufferSize);
+int sys_create_symlink(const char *path, const char *toPath);
 int sys_unlink(const char *path);
 int sys_rename(const char *oldpath, const char *newpath);
-int sys_write_stat(const char *path, struct stat *stat, int stat_mask);
+int sys_read_stat(const char *path, bool traverseLink, struct stat *stat);
+int sys_write_stat(const char *path, bool traverseLink, struct stat *stat, int statMask);
 char *sys_getcwd(char *buf, size_t size);
 int sys_setcwd(const char* path);
 
@@ -180,11 +182,12 @@ int user_create_entry_ref(dev_t device, ino_t inode, const char *uname, int omod
 int user_create(const char *path, int omode, int perms);
 int user_create_dir_entry_ref(dev_t device, ino_t inode, const char *name, int perms);
 int user_create_dir(const char *path, int perms);
-int user_symlink(const char *path, const char *toPath);
+int user_read_link(const char *path, char *buffer, size_t bufferSize);
+int user_create_symlink(const char *path, const char *toPath);
 int user_unlink(const char *path);
 int user_rename(const char *oldpath, const char *newpath);
-int user_read_stat(const char *path, struct stat *stat);
-int user_write_stat(const char *path, struct stat *stat, int stat_mask);
+int user_read_stat(const char *path, bool traverseLink, struct stat *stat);
+int user_write_stat(const char *path, bool traverseLink, struct stat *stat, int statMask);
 int user_getcwd(char *buf, size_t size);
 int user_setcwd(const char* path);
 
@@ -194,7 +197,6 @@ extern ssize_t sys_write(int fd, const void *buf, off_t pos, size_t len);
 extern int sys_ioctl(int fd, ulong cmd, void *data, size_t length);
 extern ssize_t sys_read_dir(int fd, struct dirent *buffer, size_t bufferSize, uint32 maxCount);
 extern status_t sys_rewind_dir(int fd);
-extern int sys_read_stat(const char *path, struct stat *stat);
 extern int sys_close(int fd);
 extern int sys_dup(int fd);
 extern int sys_dup2(int ofd, int nfd);