POSIX: add posix_fallocate and a preallocate syscall

the preallocate syscall will call the preallocate filesystem hook, if available.

fix #6285

Change-Id: Ifff4595548610c8e009d4e5ffb64c37e0884e62d
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3382
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

headers/posix/fcntl.h

@@ -99,6 +99,7 @@ extern int	openat(int fd, const char *path, int openMode, ...);
 extern int	fcntl(int fd, int op, ...);
 
 extern int	posix_fadvise(int fd, off_t offset, off_t len, int advice);
+extern int	posix_fallocate(int fd, off_t offset, off_t len);
 
 #ifdef __cplusplus
 }

headers/private/kernel/vfs.h

@@ -252,6 +252,7 @@ int			_user_dup(int fd);
 int			_user_dup2(int ofd, int nfd);
 status_t	_user_lock_node(int fd);
 status_t	_user_unlock_node(int fd);
+status_t	_user_preallocate(int fd, off_t offset, off_t length);
 
 /* socket user prototypes (implementation in socket.cpp) */
 int			_user_socket(int family, int type, int protocol);

headers/private/system/syscalls.h

@@ -338,6 +338,7 @@ extern status_t		_kern_lock_node(int fd);
 extern status_t		_kern_unlock_node(int fd);
 extern status_t		_kern_get_next_fd_info(team_id team, uint32 *_cookie,
 						struct fd_info *info, size_t infoSize);
+extern status_t		_kern_preallocate(int fd, off_t offset, off_t length);
 
 // socket functions
 extern int			_kern_socket(int family, int type, int protocol);

src/system/kernel/fs/vfs.cpp

@@ -6438,6 +6438,48 @@ common_unlock_node(int fd, bool kernel)
 }
 
 
+static status_t
+common_preallocate(int fd, off_t offset, off_t length, bool kernel)
+{
+	struct file_descriptor* descriptor;
+	struct vnode* vnode;
+
+	if (offset < 0 || length == 0)
+		return B_BAD_VALUE;
+	if (offset > OFF_MAX - length)
+		return B_FILE_TOO_LARGE;
+
+	descriptor = get_fd_and_vnode(fd, &vnode, kernel);
+	if (descriptor == NULL || (descriptor->open_mode & O_RWMASK) == O_RDONLY)
+		return B_FILE_ERROR;
+
+	switch (vnode->Type() & S_IFMT) {
+		case S_IFIFO:
+		case S_IFSOCK:
+			return ESPIPE;
+
+		case S_IFBLK:
+		case S_IFCHR:
+		case S_IFDIR:
+		case S_IFLNK:
+			return B_DEVICE_NOT_FOUND;
+
+		case S_IFREG:
+			break;
+	}
+
+	status_t status = B_OK;
+	if (HAS_FS_CALL(vnode, preallocate)) {
+		status = FS_CALL(vnode, preallocate, offset, length);
+	} else {
+		status = HAS_FS_CALL(vnode, write)
+			? B_UNSUPPORTED : B_READ_ONLY_DEVICE;
+	}
+
+	return status;
+}
+
+
 static status_t
 common_read_link(int fd, char* path, char* buffer, size_t* _bufferSize,
 	bool kernel)
@@ -8435,6 +8477,13 @@ _kern_unlock_node(int fd)
 }
 
 
+status_t
+_kern_preallocate(int fd, off_t offset, off_t length)
+{
+	return common_preallocate(fd, offset, length, true);
+}
+
+
 status_t
 _kern_create_dir_entry_ref(dev_t device, ino_t inode, const char* name,
 	int perms)
@@ -9319,6 +9368,13 @@ _user_unlock_node(int fd)
 }
 
 
+status_t
+_user_preallocate(int fd, off_t offset, off_t length)
+{
+	return common_preallocate(fd, offset, length, false);
+}
+
+
 status_t
 _user_create_dir_entry_ref(dev_t device, ino_t inode, const char* userName,
 	int perms)

src/system/libroot/posix/fcntl.cpp

@@ -95,3 +95,12 @@ posix_fadvise(int fd, off_t offset, off_t len, int advice)
 	return 0;
 }
 
+
+int
+posix_fallocate(int fd, off_t offset, off_t len)
+{
+	if (len == 0 || offset < 0)
+		return EINVAL;
+
+	return _kern_preallocate(fd, offset, len);
+}

src/system/libroot/stubbed/libroot_stubs.c

@@ -2424,6 +2424,8 @@ void popen() {}
 void port_buffer_size() {}
 void port_buffer_size_etc() {}
 void port_count() {}
+void posix_fadvise() {}
+void posix_fallocate() {}
 void posix_madvise() {}
 void posix_memalign() {}
 void posix_openpt() {}

src/system/libroot/stubbed/libroot_stubs_legacy.c

@@ -2354,6 +2354,8 @@ void popen() {}
 void port_buffer_size() {}
 void port_buffer_size_etc() {}
 void port_count() {}
+void posix_fadvise() {}
+void posix_fallocate() {}
 void posix_madvise() {}
 void posix_memalign() {}
 void posix_openpt() {}