NetBSD-5.0.2/share/doc/papers/fsinterface/slides.t
.\" $NetBSD: slides.t,v 1.3 2003/08/07 10:30:42 agc Exp $
.\"
.\" Copyright (c) 1986 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" 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 REGENTS 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 REGENTS 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
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.\" @(#)slides.t 5.2 (Berkeley) 4/16/91
.\"
.so macros
.nf
.LL
Encapsulation of namei parameters
.NP 0
.ta .5i +\w'caddr_t\0\0'u +\w'struct\0\0'u +\w'vnode *nc_prevdir;\0\0\0\0\0'u
struct nameidata {
/* arguments and context: */
caddr_t ni_dirp;
enum uio_seg ni_seg;
short ni_nameiop;
struct vnode *ni_cdir;
struct vnode *ni_rdir;
struct ucred *ni_cred;
.sp .2
/* shared with lookup and commit: */
caddr_t ni_pnbuf;
char *ni_ptr;
int ni_pathlen;
short ni_more;
short ni_loopcnt;
.sp .2
/* results: */
struct vnode *ni_vp;
struct vnode *ni_dvp;
.sp .2
/* BEGIN UFS SPECIFIC */
struct diroffcache {
struct vnode *nc_prevdir;
long nc_id;
off_t nc_prevoffset;
} ni_nc;
/* END UFS SPECIFIC */
};
.bp
.LL
Namei operations and modifiers
.NP 0
.ta \w'#define\0\0'u +\w'WANTPARENT\0\0'u +\w'0x40\0\0\0\0\0\0\0'u
#define LOOKUP 0 /* name lookup only */
#define CREATE 1 /* setup for creation */
#define DELETE 2 /* setup for deletion */
#define WANTPARENT 0x10 /* return parent vnode also */
#define NOCACHE 0x20 /* remove name from cache */
#define FOLLOW 0x40 /* follow symbolic links */
.bp
.LL
Namei operations and modifiers
.NP 0
.ta \w'#define\0\0'u +\w'WANTPARENT\0\0'u +\w'0x40\0\0\0\0\0\0\0'u
#define LOOKUP 0
#define CREATE 1
#define DELETE 2
#define WANTPARENT 0x10
#define NOCACHE 0x20
#define FOLLOW 0x40
.bp
.LL
Credentials
.NP 0
.ta .5i +\w'caddr_t\0\0\0'u +\w'struct\0\0'u +\w'vnode *nc_prevdir;\0\0\0\0\0'u
struct ucred {
u_short cr_ref;
uid_t cr_uid;
short cr_ngroups;
gid_t cr_groups[NGROUPS];
/*
* The following either should not be here,
* or should be treated as opaque.
*/
uid_t cr_ruid;
gid_t cr_svgid;
};
.bp
.LL
Scatter-gather I/O
.NP 0
.ta .5i +\w'caddr_t\0\0\0'u +\w'struct\0\0'u +\w'vnode *nc_prevdir;\0\0\0\0\0'u
struct uio {
struct iovec *uio_iov;
int uio_iovcnt;
off_t uio_offset;
int uio_resid;
enum uio_rw uio_rw;
};
enum uio_rw { UIO_READ, UIO_WRITE };
.ta .5i +\w'caddr_t\0\0\0'u +\w'vnode *nc_prevdir;\0\0\0\0\0'u
struct iovec {
caddr_t iov_base;
int iov_len;
enum uio_seg iov_segflg;
int (*iov_op)();
};
.bp
.LL
Per-filesystem information
.NP 0
.ta .25i +\w'struct vfsops\0\0\0'u +\w'*vfs_vnodecovered;\0\0\0\0\0'u
struct vfs {
struct vfs *vfs_next;
\fB+\fP struct vfs *vfs_prev;
struct vfsops *vfs_op;
struct vnode *vfs_vnodecovered;
int vfs_flag;
\fB!\fP int vfs_fsize;
\fB+\fP int vfs_bsize;
\fB!\fP uid_t vfs_exroot;
short vfs_exflags;
caddr_t vfs_data;
};
.NP 0
.ta \w'\fB+\fP 'u +\w'#define\0\0'u +\w'VFS_EXPORTED\0\0'u +\w'0x40\0\0\0\0\0'u
/* vfs flags: */
#define VFS_RDONLY 0x01
\fB+\fP #define VFS_NOEXEC 0x02
#define VFS_MLOCK 0x04
#define VFS_MWAIT 0x08
#define VFS_NOSUID 0x10
#define VFS_EXPORTED 0x20
/* exported vfs flags: */
#define EX_RDONLY 0x01
.bp
.LL
Operations supported on virtual file system.
.NP 0
.ta .25i +\w'int\0\0'u +\w'*vfs_mountroot();\0'u
struct vfsops {
\fB!\fP int (*vfs_mount)(vfs, path, data, len);
\fB!\fP int (*vfs_unmount)(vfs, forcibly);
\fB+\fP int (*vfs_mountroot)();
int (*vfs_root)(vfs, vpp);
int (*vfs_statfs)(vfs, sbp);
\fB!\fP int (*vfs_sync)(vfs, waitfor);
\fB+\fP int (*vfs_fhtovp)(vfs, fhp, vpp);
\fB+\fP int (*vfs_vptofh)(vp, fhp);
};
.bp
.LL
Dynamic file system information
.NP 0
.ta .5i +\w'struct\0\0\0'u +\w'*vfs_vnodecovered;\0\0\0\0\0'u
struct statfs {
\fB!\fP short f_type;
\fB+\fP short f_flags;
\fB!\fP long f_fsize;
\fB+\fP long f_bsize;
long f_blocks;
long f_bfree;
long f_bavail;
long f_files;
long f_ffree;
fsid_t f_fsid;
\fB+\fP char *f_mntonname;
\fB+\fP char *f_mntfromname;
long f_spare[7];
};
typedef long fsid_t[2];
.bp
.LL
Filesystem objects (vnodes)
.NP 0
.ta .25i +\w'struct vnodeops\0\0'u +\w'*v_vfsmountedhere;\0\0\0'u
enum vtype { VNON, VREG, VDIR, VBLK, VCHR, VLNK, VSOCK };
struct vnode {
u_short v_flag;
u_short v_count;
u_short v_shlockc;
u_short v_exlockc;
struct vfs *v_vfsmountedhere;
struct vfs *v_vfsp;
struct vnodeops *v_op;
\fB+\fP struct text *v_text;
enum vtype v_type;
caddr_t v_data;
};
.ta \w'#define\0\0'u +\w'NOFOLLOW\0\0'u +\w'0x40\0\0\0\0\0\0\0'u
/* vnode flags */
#define VROOT 0x01
#define VTEXT 0x02
#define VEXLOCK 0x10
#define VSHLOCK 0x20
#define VLWAIT 0x40
.bp
.LL
Operations on vnodes
.NP 0
.ta .25i +\w'int\0\0'u +\w'(*vn_getattr)(\0\0\0\0\0'u
struct vnodeops {
\fB!\fP int (*vn_lookup)(ndp);
\fB!\fP int (*vn_create)(ndp, vap, fflags);
\fB+\fP int (*vn_mknod)(ndp, vap, fflags);
\fB!\fP int (*vn_open)(vp, fflags, cred);
int (*vn_close)(vp, fflags, cred);
int (*vn_access)(vp, fflags, cred);
int (*vn_getattr)(vp, vap, cred);
int (*vn_setattr)(vp, vap, cred);
.sp .5
\fB+\fP int (*vn_read)(vp, uiop,
offp, ioflag, cred);
\fB+\fP int (*vn_write)(vp, uiop,
offp, ioflag, cred);
\fB!\fP int (*vn_ioctl)(vp, com,
data, fflag, cred);
int (*vn_select)(vp, which, cred);
\fB+\fP int (*vn_mmap)(vp, ..., cred);
int (*vn_fsync)(vp, cred);
\fB+\fP int (*vn_seek)(vp, offp, off,
whence);
.bp
.LL
Operations on vnodes (cont)
.NP 0
.ta .25i +\w'int\0\0'u +\w'(*vn_getattr)(\0\0\0\0\0'u
\fB!\fP int (*vn_remove)(ndp);
\fB!\fP int (*vn_link)(vp, ndp);
\fB!\fP int (*vn_rename)(sndp, tndp);
\fB!\fP int (*vn_mkdir)(ndp, vap);
\fB!\fP int (*vn_rmdir)(ndp);
\fB!\fP int (*vn_symlink)(ndp, vap, nm);
\fB!\fP int (*vn_readdir)(vp, uiop,
offp, ioflag, cred);
\fB!\fP int (*vn_readlink)(vp, uiop,
offp, ioflag, cred);
.sp .5
\fB+\fP int (*vn_abortop)(ndp);
\fB!\fP int (*vn_inactive)(vp);
};
.NP 0
.ta \w'#define\0\0'u +\w'NOFOLLOW\0\0'u +\w'0x40\0\0\0\0\0'u
/* flags for ioflag */
#define IO_UNIT 0x01
#define IO_APPEND 0x02
#define IO_SYNC 0x04
.bp
.LL
Vnode attributes
.NP 0
.ta .5i +\w'struct timeval\0\0'u +\w'*v_vfsmountedhere;\0\0\0'u
struct vattr {
enum vtype va_type;
u_short va_mode;
\fB!\fP uid_t va_uid;
\fB!\fP gid_t va_gid;
long va_fsid;
\fB!\fP long va_fileid;
short va_nlink;
u_long va_size;
\fB+\fP u_long va_size1;
long va_blocksize;
struct timeval va_atime;
struct timeval va_mtime;
struct timeval va_ctime;
dev_t va_rdev;
\fB!\fP u_long va_bytes;
\fB+\fP u_long va_bytes1;
};