/* * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009 * The President and Fellows of Harvard College. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef _VFS_H_ #define _VFS_H_ #include <array.h> /* * Virtual File System layer functions. * * The VFS layer translates operations on abstract on-disk files or * pathnames to operations on specific files on specific filesystems. */ struct uio; /* kernel or userspace I/O buffer (uio.h) */ struct device; /* abstract structure for a device (dev.h) */ struct fs; /* abstract structure for a filesystem (fs.h) */ struct vnode; /* abstract structure for an on-disk file (vnode.h) */ /* * VFS layer low-level operations. * See vnode.h for direct operations on vnodes. * See fs.h for direct operations on filesystems/devices. * * vfs_setcurdir - change current directory of current thread by vnode * vfs_clearcurdir - change current directory of current thread to "none" * vfs_getcurdir - retrieve vnode of current directory of current thread * vfs_sync - force all dirty buffers to disk * vfs_getroot - get root vnode for the filesystem named DEVNAME * vfs_getdevname - get mounted device name for the filesystem passed in */ int vfs_setcurdir(struct vnode *dir); int vfs_clearcurdir(void); int vfs_getcurdir(struct vnode **retdir); int vfs_sync(void); int vfs_getroot(const char *devname, struct vnode **result); const char *vfs_getdevname(struct fs *fs); /* * VFS layer mid-level operations. * * vfs_lookup - Like VOP_LOOKUP, but takes a full device:path name, * or a name relative to the current directory, and * goes to the correct filesystem. * vfs_lookparent - Likewise, for VOP_LOOKPARENT. * * Both of these may destroy the path passed in. */ int vfs_lookup(char *path, struct vnode **result); int vfs_lookparent(char *path, struct vnode **result, char *buf, size_t buflen); /* * VFS layer high-level operations on pathnames * Because lookup may destroy pathnames, these all may too. * * vfs_open - Open or create a file. FLAGS/MODE per the syscall. * vfs_readlink - Read contents of a symlink into a uio. * vfs_symlink - Create a symlink PATH containing contents CONTENTS. * vfs_mkdir - Create a directory. MODE per the syscall. * vfs_link - Create a hard link to a file. * vfs_remove - Delete a file. * vfs_rmdir - Delete a directory. * vfs_rename - rename a file. * * vfs_chdir - Change current directory of current thread by name. * vfs_getcwd - Retrieve name of current directory of current thread. * * vfs_close - Close a vnode opened with vfs_open. Does not fail. * (See vfspath.c for a discussion of why.) */ int vfs_open(char *path, int openflags, mode_t mode, struct vnode **ret); void vfs_close(struct vnode *vn); int vfs_readlink(char *path, struct uio *data); int vfs_symlink(const char *contents, char *path); int vfs_mkdir(char *path, mode_t mode); int vfs_link(char *oldpath, char *newpath); int vfs_remove(char *path); int vfs_rmdir(char *path); int vfs_rename(char *oldpath, char *newpath); int vfs_chdir(char *path); int vfs_getcwd(struct uio *buf); /* * Misc * * vfs_bootstrap - Call during system initialization to allocate * structures. * * vfs_setbootfs - Set the filesystem that paths beginning with a * slash are sent to. If not set, these paths fail * with ENOENT. The argument should be the device * name or volume name for the filesystem (such as * "lhd0:") but need not have the trailing colon. * * vfs_clearbootfs - Clear the bootfs filesystem. This should be * done during shutdown so that the filesystem in * question can be unmounted. * * vfs_adddev - Add a device to the VFS named device list. If * MOUNTABLE is zero, the device will be accessible * as "DEVNAME:". If the mountable flag is set, the * device will be accessible as "DEVNAMEraw:" and * mountable under the name "DEVNAME". Thus, the * console, added with MOUNTABLE not set, would be * accessed by pathname as "con:", and lhd0, added * with mountable set, would be accessed by * pathname as "lhd0raw:" and mounted by passing * "lhd0" to vfs_mount. * * vfs_addfs - Add a hardwired filesystem to the VFS named device * list. It will be accessible as "devname:". This is * intended for filesystem-devices like emufs, and * gizmos like Linux procfs or BSD kernfs, not for * mounting filesystems on disk devices. * * vfs_mount - Attempt to mount a filesystem on a device. The * device named by DEVNAME will be looked up and * passed, along with DATA, to the supplied function * MOUNTFUNC, which should create a struct fs and * return it in RESULT. * * vfs_unmount - Unmount the filesystem presently mounted on the * specified device. * * vfs_unmountall - Unmount all mounted filesystems. */ void vfs_bootstrap(void); int vfs_setbootfs(const char *fsname); void vfs_clearbootfs(void); int vfs_adddev(const char *devname, struct device *dev, int mountable); int vfs_addfs(const char *devname, struct fs *fs); int vfs_mount(const char *devname, void *data, int (*mountfunc)(void *data, struct device *dev, struct fs **result)); int vfs_unmount(const char *devname); int vfs_unmountall(void); /* * Array of vnodes. */ #ifndef VFSINLINE #define VFSINLINE INLINE #endif DECLARRAY(vnode, VFSINLINE); DEFARRAY(vnode, VFSINLINE); /* * Global one-big-lock for all filesystem operations. * You must remove this for the filesystem assignment. */ void vfs_biglock_acquire(void); void vfs_biglock_release(void); bool vfs_biglock_do_i_hold(void); #endif /* _VFS_H_ */