X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/7cdbcf53d7627f600040eb816c8527a29dda5933..bb1b75f494bfb7e8bd5eda8382452308ca3aad72:/usr/src/sys/ufs/ffs/ffs_vnops.c diff --git a/usr/src/sys/ufs/ffs/ffs_vnops.c b/usr/src/sys/ufs/ffs/ffs_vnops.c index 4c0c00252b..fa49715ee2 100644 --- a/usr/src/sys/ufs/ffs/ffs_vnops.c +++ b/usr/src/sys/ufs/ffs/ffs_vnops.c @@ -1,50 +1,442 @@ -/* ffs_vnops.c 4.11 81/08/12 */ +/* ffs_vnops.c 4.54 83/03/31 */ #include "../h/param.h" #include "../h/systm.h" -#include "../h/mount.h" -#include "../h/ino.h" -#include "../h/reg.h" -#include "../h/buf.h" -#include "../h/filsys.h" #include "../h/dir.h" #include "../h/user.h" -#include "../h/inode.h" +#include "../h/kernel.h" #include "../h/file.h" -#include "../h/conf.h" #include "../h/stat.h" -#include "../h/inline.h" +#include "../h/inode.h" +#include "../h/fs.h" +#include "../h/buf.h" +#include "../h/proc.h" +#include "../h/quota.h" +#include "../h/descrip.h" +#include "../h/uio.h" +#include "../h/socket.h" +#include "../h/socketvar.h" +#include "../h/nami.h" /* - * the fstat system call. + * Change current working directory (``.''). */ -fstat() +chdir() +{ + + chdirec(&u.u_cdir); +} + +/* + * Change notion of root (``/'') directory. + */ +chroot() +{ + + if (suser()) + chdirec(&u.u_rdir); +} + +/* + * Common routine for chroot and chdir. + */ +chdirec(ipp) + register struct inode **ipp; +{ + register struct inode *ip; + struct a { + char *fname; + }; + + ip = namei(uchar, LOOKUP, 1); + if (ip == NULL) + return; + if ((ip->i_mode&IFMT) != IFDIR) { + u.u_error = ENOTDIR; + goto bad; + } + if (access(ip, IEXEC)) + goto bad; + iunlock(ip); + if (*ipp) + irele(*ipp); + *ipp = ip; + return; + +bad: + iput(ip); +} + +/* + * Open system call. + */ +open() +{ + register struct inode *ip; + register struct a { + char *fname; + int flags; + int mode; + } *uap; + int checkpermissions = 1, flags; + + uap = (struct a *)u.u_ap; + flags = uap->flags + 1; + if ((flags&FTRUNCATE) && (flags&FWRITE) == 0) { + u.u_error = EINVAL; + return; + } + if (flags&FCREATE) { + ip = namei(uchar, CREATE, 1); + if (ip == NULL) { + if (u.u_error) + return; + ip = maknode(uap->mode&07777&(~ISVTX)); + checkpermissions = 0; + flags &= ~FTRUNCATE; + } + } else + ip = namei(uchar, LOOKUP, 1); + if (ip == NULL) + return; + open1(ip, flags, checkpermissions); +} + +#ifndef NOCOMPAT +/* + * Creat system call. + */ +ocreat() +{ + register struct inode *ip; + register struct a { + char *fname; + int fmode; + } *uap; + + uap = (struct a *)u.u_ap; + ip = namei(uchar, CREATE, 1); + if (ip == NULL) { + if (u.u_error) + return; + ip = maknode(uap->fmode&07777&(~ISVTX)); + if (ip == NULL) + return; + open1(ip, FWRITE, 0); + } else + open1(ip, FWRITE|FTRUNCATE, 1); +} +#endif + +/* + * Common code for open and creat. + * Check permissions (if we haven't done so already), + * allocate an open file structure, and call + * the device open routine, if any. + */ +open1(ip, mode, checkpermissions) + register struct inode *ip; + register mode; { register struct file *fp; + int i, flags; + + if (checkpermissions) { + if (mode&FREAD) + if (access(ip, IREAD)) + goto bad; + if (mode&FWRITE) { + if (access(ip, IWRITE)) + goto bad; + if ((ip->i_mode&IFMT) == IFDIR) { + u.u_error = EISDIR; + goto bad; + } + } + } + + /* + * Check locking on inode. Release "inode lock" + * while doing so in case we block inside flocki. + */ + flags = 0; + if (mode&(FSHLOCK|FEXLOCK)) { + iunlock(ip); + flags = flocki(ip, 0, mode); + ilock(ip); + if (u.u_error) + goto bad; + } + if (mode&FTRUNCATE) + itrunc(ip, (u_long)0); + iunlock(ip); + if ((fp = falloc()) == NULL) + goto out; + fp->f_flag = mode & FMODES; + fp->f_type = DTYPE_FILE; + i = u.u_r.r_val1; + fp->f_inode = ip; + u.u_error = openi(ip, mode); + if (u.u_error == 0) { + u.u_pofile[i] = flags; + return; + } + u.u_ofile[i] = NULL; + fp->f_count--; +out: + irele(ip); + return; +bad: + iput(ip); +} + +/* + * Mknod system call + */ +mknod() +{ + register struct inode *ip; register struct a { - int fdes; - struct stat *sb; + char *fname; + int fmode; + int dev; } *uap; uap = (struct a *)u.u_ap; - fp = getf(uap->fdes); - if(fp == NULL) + if (suser()) { + ip = namei(uchar, CREATE, 0); + if (ip != NULL) { + u.u_error = EEXIST; + goto out; + } + } + if (u.u_error) return; - if (fp->f_flag&FPORT) { - ptstat(fp); + ip = maknode(uap->fmode); + if (ip == NULL) return; + if (uap->dev) { + /* + * Want to be able to use this to make badblock + * inodes, so don't truncate the dev number. + */ + ip->i_rdev = uap->dev; + ip->i_flag |= IACC|IUPD|ICHG; } -#ifdef BBNNET - if (fp->f_flag&FNET) { - u.u_error = EINVAL; + +out: + iput(ip); +} + +/* + * link system call + */ +link() +{ + register struct inode *ip, *xp; + register struct a { + char *target; + char *linkname; + } *uap; + + uap = (struct a *)u.u_ap; + ip = namei(uchar, LOOKUP, 1); /* well, this routine is doomed anyhow */ + if (ip == NULL) + return; + if ((ip->i_mode&IFMT) == IFDIR && !suser()) { + iput(ip); return; } -#endif - stat1(fp->f_inode, uap->sb); + ip->i_nlink++; + ip->i_flag |= ICHG; + iupdat(ip, &time, &time, 1); + iunlock(ip); + u.u_dirp = (caddr_t)uap->linkname; + xp = namei(uchar, CREATE, 0); + if (xp != NULL) { + u.u_error = EEXIST; + iput(xp); + goto out; + } + if (u.u_error) + goto out; + if (u.u_pdir->i_dev != ip->i_dev) { + iput(u.u_pdir); + u.u_error = EXDEV; + goto out; + } + u.u_error = direnter(ip); +out: + if (u.u_error) { + ip->i_nlink--; + ip->i_flag |= ICHG; + } + irele(ip); +} + +/* + * symlink -- make a symbolic link + */ +symlink() +{ + register struct a { + char *target; + char *linkname; + } *uap; + register struct inode *ip; + register char *tp; + register c, nc; + + uap = (struct a *)u.u_ap; + tp = uap->target; + nc = 0; + while (c = fubyte(tp)) { + if (c < 0) { + u.u_error = EFAULT; + return; + } + tp++; + nc++; + } + u.u_dirp = uap->linkname; + ip = namei(uchar, CREATE, 0); + if (ip) { + iput(ip); + u.u_error = EEXIST; + return; + } + if (u.u_error) + return; + ip = maknode(IFLNK | 0777); + if (ip == NULL) + return; + u.u_error = rdwri(UIO_WRITE, ip, uap->target, nc, 0, 0, (int *)0); + /* handle u.u_error != 0 */ + iput(ip); +} + +/* + * Unlink system call. + * Hard to avoid races here, especially + * in unlinking directories. + */ +unlink() +{ + struct a { + char *fname; + }; + register struct inode *ip, *dp; + + ip = namei(uchar, DELETE | LOCKPARENT, 0); + if (ip == NULL) + return; + dp = u.u_pdir; + if ((ip->i_mode&IFMT) == IFDIR && !suser()) + goto out; + /* + * Don't unlink a mounted file. + */ + if (ip->i_dev != dp->i_dev) { + u.u_error = EBUSY; + goto out; + } + if (ip->i_flag&ITEXT) + xrele(ip); /* try once to free text */ + if (dirremove()) { + ip->i_nlink--; + ip->i_flag |= ICHG; + } +out: + if (dp == ip) + irele(ip); + else + iput(ip); + iput(dp); +} + +/* + * Seek system call + */ +lseek() +{ + register struct file *fp; + register struct a { + int fd; + off_t off; + int sbase; + } *uap; + + uap = (struct a *)u.u_ap; + fp = getf(uap->fd); + if (fp == NULL) + return; + if (fp->f_type == DTYPE_SOCKET) { + u.u_error = ESPIPE; + return; + } + if (uap->sbase == FSEEK_RELATIVE) + uap->off += fp->f_offset; + else if (uap->sbase == FSEEK_EOF) + uap->off += fp->f_inode->i_size; + fp->f_offset = uap->off; + u.u_r.r_off = uap->off; +} + +/* + * Access system call + */ +saccess() +{ + register svuid, svgid; + register struct inode *ip; + register struct a { + char *fname; + int fmode; + } *uap; + + uap = (struct a *)u.u_ap; + svuid = u.u_uid; + svgid = u.u_gid; + u.u_uid = u.u_ruid; + u.u_gid = u.u_rgid; + ip = namei(uchar, LOOKUP, 1); + if (ip != NULL) { + if ((uap->fmode&FACCESS_READ) && access(ip, IREAD)) + goto done; + if ((uap->fmode&FACCESS_WRITE) && access(ip, IWRITE)) + goto done; + if ((uap->fmode&FACCESS_EXECUTE) && access(ip, IEXEC)) + goto done; +done: + iput(ip); + } + u.u_uid = svuid; + u.u_gid = svgid; +} + +/* + * the fstat system call. + */ +fstat() +{ + register struct file *fp; + register struct a { + int fd; + struct stat *sb; + } *uap; + + uap = (struct a *)u.u_ap; + fp = getf(uap->fd); + if (fp == NULL) + return; + if (fp->f_type == DTYPE_SOCKET) + u.u_error = sostat(fp->f_socket, uap->sb); + else + stat1(fp->f_inode, uap->sb); } /* - * the stat system call. + * Stat system call. This version follows links. */ stat() { @@ -55,8 +447,27 @@ stat() } *uap; uap = (struct a *)u.u_ap; - ip = namei(uchar, 0); - if(ip == NULL) + ip = namei(uchar, LOOKUP, 1); + if (ip == NULL) + return; + stat1(ip, uap->sb); + iput(ip); +} + +/* + * Lstat system call. This version does not follow links. + */ +lstat() +{ + register struct inode *ip; + register struct a { + char *fname; + struct stat *sb; + } *uap; + + uap = (struct a *)u.u_ap; + ip = namei(uchar, LOOKUP, 0); + if (ip == NULL) return; stat1(ip, uap->sb); iput(ip); @@ -67,16 +478,14 @@ stat() * get the inode and pass appropriate parts back. */ stat1(ip, ub) -register struct inode *ip; -struct stat *ub; + register struct inode *ip; + struct stat *ub; { - register struct dinode *dp; - register struct buf *bp; struct stat ds; IUPDAT(ip, &time, &time, 0); /* - * first copy from inode table + * Copy from inode table */ ds.st_dev = ip->i_dev; ds.st_ino = ip->i_number; @@ -84,208 +493,733 @@ struct stat *ub; ds.st_nlink = ip->i_nlink; ds.st_uid = ip->i_uid; ds.st_gid = ip->i_gid; - ds.st_rdev = (dev_t)ip->i_un.i_rdev; + ds.st_rdev = (dev_t)ip->i_rdev; ds.st_size = ip->i_size; - /* - * next the dates in the disk - */ - bp = bread(ip->i_dev, itod(ip->i_number)); - dp = bp->b_un.b_dino; - dp += itoo(ip->i_number); - ds.st_atime = dp->di_atime; - ds.st_mtime = dp->di_mtime; - ds.st_ctime = dp->di_ctime; - brelse(bp); - if (copyout((caddr_t)&ds, (caddr_t)ub, sizeof(ds)) < 0) - u.u_error = EFAULT; + ds.st_atime = ip->i_atime; + ds.st_spare1 = 0; + ds.st_mtime = ip->i_mtime; + ds.st_spare2 = 0; + ds.st_ctime = ip->i_ctime; + ds.st_spare3 = 0; + /* this doesn't belong here */ + if ((ip->i_mode&IFMT) == IFBLK) + ds.st_blksize = BLKDEV_IOSIZE; + else if ((ip->i_mode&IFMT) == IFCHR) + ds.st_blksize = MAXBSIZE; + else + ds.st_blksize = ip->i_fs->fs_bsize; + ds.st_spare4[0] = ds.st_spare4[1] = ds.st_spare4[2] = 0; + u.u_error = copyout((caddr_t)&ds, (caddr_t)ub, sizeof(ds)); } /* - * the dup system call. + * Return target name of a symbolic link */ -dup() +readlink() { - register struct file *fp; + register struct inode *ip; register struct a { - int fdes; - int fdes2; + char *name; + char *buf; + int count; + } *uap = (struct a *)u.u_ap; + int resid; + + ip = namei(uchar, LOOKUP, 0); + if (ip == NULL) + return; + if ((ip->i_mode&IFMT) != IFLNK) { + u.u_error = ENXIO; + goto out; + } + u.u_error = rdwri(UIO_READ, ip, uap->buf, uap->count, 0, 0, &resid); +out: + iput(ip); + u.u_r.r_val1 = uap->count - resid; +} + +/* + * Change mode of a file given path name. + */ +chmod() +{ + struct inode *ip; + struct a { + char *fname; + int fmode; } *uap; - register i, m; uap = (struct a *)u.u_ap; - m = uap->fdes & ~077; - uap->fdes &= 077; - fp = getf(uap->fdes); - if(fp == NULL) + if ((ip = owner(1)) == NULL) + return; + chmod1(ip, uap->fmode); + iput(ip); +} + +/* + * Change mode of a file given a file descriptor. + */ +fchmod() +{ + struct a { + int fd; + int fmode; + } *uap; + register struct inode *ip; + register struct file *fp; + + uap = (struct a *)u.u_ap; + fp = getf(uap->fd); + if (fp == NULL) + return; + if (fp->f_type == DTYPE_SOCKET) { + u.u_error = EINVAL; return; - if ((m&0100) == 0) { - if ((i = ufalloc()) < 0) - return; - } else { - i = uap->fdes2; - if (i<0 || i>=NOFILE) { - u.u_error = EBADF; - return; - } - if (u.u_vrpages[i]) { - u.u_error = ETXTBSY; - return; - } - u.u_r.r_val1 = i; - } - if (i!=uap->fdes) { - if (u.u_ofile[i]!=NULL) - closef(u.u_ofile[i]); - u.u_ofile[i] = fp; - fp->f_count++; } + ip = fp->f_inode; + if (u.u_uid != ip->i_uid && !suser()) + return; + ilock(ip); + chmod1(ip, uap->fmode); + iunlock(ip); } /* - * the mount system call. + * Change the mode on a file. + * Inode must be locked before calling. */ -smount() { - dev_t dev; +chmod1(ip, mode) register struct inode *ip; - register struct mount *mp; - struct mount *smp; - register struct filsys *fp; - struct buf *bp; - register struct a { - char *fspec; - char *freg; - int ronly; + register int mode; +{ + register int *gp; + + ip->i_mode &= ~07777; + if (u.u_uid) { + mode &= ~ISVTX; + if (!groupmember(ip->i_gid)) + mode &= ~ISGID; +#ifdef MUSH + if (u.u_quota->q_syflags & QF_UMASK && + (ip->i_mode & IFMT) != IFCHR) + mode &= ~u.u_cmask; +#endif + } + ip->i_mode |= mode&07777; + ip->i_flag |= ICHG; + if (ip->i_flag&ITEXT && (ip->i_mode&ISVTX)==0) + xrele(ip); +} + +/* + * Set ownership given a path name. + */ +chown() +{ + struct inode *ip; + struct a { + char *fname; + int uid; + int gid; } *uap; - register char *cp; uap = (struct a *)u.u_ap; - dev = getmdev(); - if(u.u_error) + if ((ip = owner(0)) == NULL) return; - u.u_dirp = (caddr_t)uap->freg; - ip = namei(uchar, 0); - if(ip == NULL) + u.u_error = chown1(ip, uap->uid, uap->gid); + iput(ip); +} + +/* + * Set ownership given a file descriptor. + */ +fchown() +{ + struct a { + int fd; + int uid; + int gid; + } *uap; + register struct inode *ip; + register struct file *fp; + + uap = (struct a *)u.u_ap; + fp = getf(uap->fd); + if (fp == NULL) + return; + if (fp->f_type == DTYPE_SOCKET) { + u.u_error = EINVAL; return; - if(ip->i_count!=1 || (ip->i_mode&(IFBLK&IFCHR))!=0) - goto out; - smp = NULL; - for(mp = &mount[0]; mp < &mount[NMOUNT]; mp++) { - if(mp->m_bufp != NULL) { - if(dev == mp->m_dev) - goto out; - } else - if(smp == NULL) - smp = mp; } - mp = smp; - if(mp == NULL) - goto out; - (*bdevsw[major(dev)].d_open)(dev, !uap->ronly); - if(u.u_error) - goto out; - bp = bread(dev, SUPERB); - if(u.u_error) { - brelse(bp); - goto out1; - } - mp->m_inodp = ip; - mp->m_dev = dev; - bp->b_flags |= B_LOCKED; - mp->m_bufp = bp; - fp = bp->b_un.b_filsys; - fp->s_ilock = 0; - fp->s_flock = 0; - fp->s_ronly = uap->ronly & 1; - fp->s_nbehind = 0; - fp->s_lasti = 1; - u.u_dirp = uap->freg; - for (cp = fp->s_fsmnt; cp < &fp->s_fsmnt[sizeof (fp->s_fsmnt) - 1]; ) - if ((*cp++ = uchar()) == 0) - u.u_dirp--; /* get 0 again */ - *cp = 0; - brelse(bp); - ip->i_flag |= IMOUNT; - prele(ip); - return; + ip = fp->f_inode; + if (ip->i_uid != u.u_uid && !suser()) + return; + ilock(ip); + u.u_error = chown1(ip, uap->uid, uap->gid); + iunlock(ip); +} -out: - u.u_error = EBUSY; -out1: - iput(ip); +/* + * Perform chown operation on inode ip; + * inode must be locked prior to call. + */ +chown1(ip, uid, gid) + register struct inode *ip; + int uid, gid; +{ +#ifdef QUOTA + register long change; +#endif + + if (uid == -1) + uid = ip->i_uid; + if (gid == -1) + gid = ip->i_gid; + if (u.u_uid && ip->i_gid != gid && !groupmember(gid)) + return (EPERM); +#ifdef QUOTA + /* + * This doesn't allow for holes in files (which hopefully don't + * happen often in files that we chown), and is not accurate anyway + * (eg: it totally ignores 3 level indir blk files - but hopefully + * noone who can make a file that big will have a quota) + */ + if (ip->i_uid == uid) + change = 0; + else { + register struct fs *fs = ip->i_fs; + + if (ip->i_size > (change = NDADDR * fs->fs_bsize)) { + register off_t size; + + size = blkroundup(fs, ip->i_size) - change; + change += size; + change += fs->fs_bsize; + /* this assumes NIADDR <= 2 */ + if (size > NINDIR(fs) * fs->fs_bsize) + change += fs->fs_bsize; + } else + change = fragroundup(fs, ip->i_size); + change /= DEV_BSIZE; + } + (void)chkdq(ip, -change, 1); + (void)chkiq(ip->i_dev, ip, ip->i_uid, 1); + dqrele(ip->i_dquot); +#endif + ip->i_uid = uid; + ip->i_gid = gid; + ip->i_flag |= ICHG; + if (u.u_ruid != 0) + ip->i_mode &= ~(ISUID|ISGID); +#ifdef QUOTA + ip->i_dquot = inoquota(ip); + (void)chkdq(ip, change, 1); + (void)chkiq(ip->i_dev, (struct inode *)NULL, uid, 1); + return (u.u_error); +#endif + return (0); } +#ifndef NOCOMPAT /* - * the umount system call. + * Set IUPD and IACC times on file. + * Can't set ICHG. */ -sumount() +outime() { - dev_t dev; + register struct a { + char *fname; + time_t *tptr; + } *uap = (struct a *)u.u_ap; register struct inode *ip; - register struct mount *mp; - struct buf *bp; - int stillopen, flag; + time_t tv[2]; + struct timeval tv0, tv1; + + if ((ip = owner(1)) == NULL) + return; + u.u_error = copyin((caddr_t)uap->tptr, (caddr_t)tv, sizeof (tv)); + if (u.u_error == 0) { + ip->i_flag |= IACC|IUPD|ICHG; + tv0.tv_sec = tv[0]; tv0.tv_usec = 0; + tv1.tv_sec = tv[1]; tv1.tv_usec = 0; + iupdat(ip, &tv0, &tv1, 0); + } + iput(ip); +} +#endif + +utimes() +{ register struct a { - char *fspec; - }; + char *fname; + struct timeval *tptr; + } *uap = (struct a *)u.u_ap; + register struct inode *ip; + struct timeval tv[2]; - dev = getmdev(); - if(u.u_error) + if ((ip = owner(1)) == NULL) return; - xumount(dev); /* remove unused sticky files from text table */ + u.u_error = copyin((caddr_t)uap->tptr, (caddr_t)tv, sizeof (tv)); + if (u.u_error == 0) { + ip->i_flag |= IACC|IUPD|ICHG; + iupdat(ip, &tv[0], &tv[1], 0); + } + iput(ip); +} + +/* + * Flush any pending I/O. + */ +sync() +{ + update(); - for(mp = &mount[0]; mp < &mount[NMOUNT]; mp++) - if(mp->m_bufp != NULL && dev == mp->m_dev) - goto found; - u.u_error = EINVAL; - return; +} + +/* + * Apply an advisory lock on a file descriptor. + */ +flock() +{ + struct a { + int fd; + int how; + } *uap; + register struct file *fp; + register int cmd, flags; -found: - stillopen = 0; - for(ip = inode; ip < inodeNINODE; ip++) - if (ip->i_number != 0 && dev == ip->i_dev) { - u.u_error = EBUSY; + uap = (struct a *)u.u_ap; + fp = getf(uap->fd); + if (fp == NULL) + return; + if (fp->f_type == DTYPE_SOCKET) { /* XXX */ + u.u_error = EINVAL; + return; + } + cmd = uap->how; + flags = u.u_pofile[uap->fd] & (UF_SHLOCK|UF_EXLOCK); + if (cmd&FUNLOCK) { + if (flags == 0) { + u.u_error = EINVAL; return; - } else if (ip->i_number != 0 && (ip->i_mode&IFMT) == IFBLK && - ip->i_un.i_rdev == dev) - stillopen++; - ip = mp->m_inodp; - ip->i_flag &= ~IMOUNT; - plock(ip); + } + funlocki(fp->f_inode, flags); + u.u_pofile[uap->fd] &= ~(UF_SHLOCK|UF_EXLOCK); + return; + } + /* + * No reason to write lock a file we've already + * write locked, similarly with a read lock. + */ + if ((flags&UF_EXLOCK) && (cmd&FEXLOCK) || + (flags&UF_SHLOCK) && (cmd&FSHLOCK)) + return; + u.u_pofile[uap->fd] = flocki(fp->f_inode, u.u_pofile[uap->fd], cmd); +} + +/* + * Truncate a file given its path name. + */ +truncate() +{ + struct a { + char *fname; + u_long length; + } *uap = (struct a *)u.u_ap; + struct inode *ip; + + ip = namei(uchar, LOOKUP, 1); + if (ip == NULL) + return; + if (access(ip, IWRITE)) + goto bad; + if ((ip->i_mode&IFMT) == IFDIR) { + u.u_error = EISDIR; + goto bad; + } + itrunc(ip, uap->length); +bad: iput(ip); - if ((bp = getblk(dev, SUPERB)) != mp->m_bufp) - panic("umount"); - bp->b_flags &= ~B_LOCKED; - flag = !bp->b_un.b_filsys->s_ronly; - mp->m_bufp = NULL; - brelse(bp); - mpurge(mp - &mount[0]); - if (!stillopen) { - (*bdevsw[major(dev)].d_close)(dev, flag); - binval(dev); +} + +/* + * Truncate a file given a file descriptor. + */ +ftruncate() +{ + struct a { + int fd; + u_long length; + } *uap = (struct a *)u.u_ap; + struct inode *ip; + struct file *fp; + + fp = getf(uap->fd); + if (fp == NULL) + return; + if (fp->f_type == DTYPE_SOCKET) { + u.u_error = EINVAL; + return; + } + if ((fp->f_flag&FWRITE) == 0) { + u.u_error = EINVAL; + return; + } + ip = fp->f_inode; + ilock(ip); + itrunc(ip, uap->length); + iunlock(ip); +} + +/* + * Synch an open file. + */ +fsync() +{ + struct a { + int fd; + } *uap = (struct a *)u.u_ap; + struct inode *ip; + struct file *fp; + + fp = getf(uap->fd); + if (fp == NULL) + return; + if (fp->f_type == DTYPE_SOCKET) { + u.u_error = EINVAL; + return; + } + ip = fp->f_inode; + ilock(ip); + syncip(ip); + iunlock(ip); +} + +/* + * Rename system call. + * rename("foo", "bar"); + * is essentially + * unlink("bar"); + * link("foo", "bar"); + * unlink("foo"); + * but ``atomically''. Can't do full commit without saving state in the + * inode on disk which isn't feasible at this time. Best we can do is + * always guarantee the target exists. + * + * Basic algorithm is: + * + * 1) Bump link count on source while we're linking it to the + * target. This also insure the inode won't be deleted out + * from underneath us while we work. + * 2) Link source to destination. If destination already exists, + * delete it first. + * 3) Unlink source reference to inode if still around. + * 4) If a directory was moved and the parent of the destination + * is different from the source, patch the ".." entry in the + * directory. + * + * Source and destination must either both be directories, or both + * not be directories. If target is a directory, it must be empty. + */ +rename() +{ + struct a { + char *from; + char *to; + } *uap; + register struct inode *ip, *xp, *dp; + int oldparent, parentdifferent, doingdirectory; + int error = 0; + + uap = (struct a *)u.u_ap; + ip = namei(uchar, DELETE | LOCKPARENT, 0); + if (ip == NULL) + return; + dp = u.u_pdir; + oldparent = 0, doingdirectory = 0; + if ((ip->i_mode&IFMT) == IFDIR) { + register struct direct *d; + + d = &u.u_dent; + /* + * Avoid ".", "..", and aliases of "." for obvious reasons. + */ + if ((d->d_namlen == 1 && d->d_name[0] == '.') || + (d->d_namlen == 2 && bcmp(d->d_name, "..", 2) == 0) || + (dp == ip)) { + iput(dp); + if (dp == ip) + irele(ip); + else + iput(ip); + u.u_error = EINVAL; + return; + } + oldparent = dp->i_number; + doingdirectory++; + } + iput(dp); + + /* + * 1) Bump link count while we're moving stuff + * around. If we crash somewhere before + * completing our work, the link count + * may be wrong, but correctable. + */ + ip->i_nlink++; + ip->i_flag |= ICHG; + iupdat(ip, &time, &time, 1); + iunlock(ip); + + /* + * When the target exists, both the directory + * and target inodes are returned locked. + */ + u.u_dirp = (caddr_t)uap->to; + xp = namei(uchar, CREATE | LOCKPARENT, 0); + if (u.u_error) { + error = u.u_error; + goto out; + } + dp = u.u_pdir; + /* + * If ".." must be changed (ie the directory gets a new + * parent) then the user must have write permission. + */ + parentdifferent = oldparent != dp->i_number; + if (doingdirectory && parentdifferent && access(ip, IWRITE)) + goto bad; + /* + * 2) If target doesn't exist, link the target + * to the source and unlink the source. + * Otherwise, rewrite the target directory + * entry to reference the source inode and + * expunge the original entry's existence. + */ + if (xp == NULL) { + if (dp->i_dev != ip->i_dev) { + error = EXDEV; + goto bad; + } + /* + * Disallow rename(foo, foo/bar). + */ + if (dp->i_number == ip->i_number) { + error = EEXIST; + goto bad; + } + /* + * Account for ".." in directory. + * When source and destination have the + * same parent we don't fool with the + * link count -- this isn't required + * because we do a similar check below. + */ + if (doingdirectory && parentdifferent) { + dp->i_nlink++; + dp->i_flag |= ICHG; + iupdat(dp, &time, &time, 1); + } + error = direnter(ip); + if (error) + goto out; + } else { + if (xp->i_dev != dp->i_dev || xp->i_dev != ip->i_dev) { + error = EXDEV; + goto bad; + } + /* + * Short circuit rename(foo, foo). + */ + if (xp->i_number == ip->i_number) + goto bad; + /* + * Target must be empty if a directory + * and have no links to it. + * Also, insure source and target are + * compatible (both directories, or both + * not directories). + */ + if ((xp->i_mode&IFMT) == IFDIR) { + if (!dirempty(xp) || xp->i_nlink > 2) { + error = ENOTEMPTY; + goto bad; + } + if (!doingdirectory) { + error = ENOTDIR; + goto bad; + } + } else if (doingdirectory) { + error = EISDIR; + goto bad; + } + dirrewrite(dp, ip); + if (u.u_error) { + error = u.u_error; + goto bad1; + } + /* + * Adjust the link count of the target to + * reflect the dirrewrite above. If this is + * a directory it is empty and there are + * no links to it, so we can squash the inode and + * any space associated with it. We disallowed + * renaming over top of a directory with links to + * it above, as we've no way to determine if + * we've got a link or the directory itself, and + * if we get a link, then ".." will be screwed up. + */ + xp->i_nlink--; + if (doingdirectory) { + if (--xp->i_nlink != 0) + panic("rename: linked directory"); + itrunc(xp, (u_long)0); + } + xp->i_flag |= ICHG; + iput(xp); + xp = NULL; } + + /* + * 3) Unlink the source. + */ + u.u_dirp = uap->from; + dp = namei(uchar, DELETE, 0); + /* + * Insure directory entry still exists and + * has not changed since the start of all + * this. If either has occured, forget about + * about deleting the original entry and just + * adjust the link count in the inode. + */ + if (dp == NULL || u.u_dent.d_ino != ip->i_number) { + ip->i_nlink--; + ip->i_flag |= ICHG; + } else { + /* + * If source is a directory, must adjust + * link count of parent directory also. + * If target didn't exist and source and + * target have the same parent, then we + * needn't touch the link count, it all + * balances out in the end. Otherwise, we + * must do so to reflect deletion of ".." + * done above. + */ + if (doingdirectory && (xp != NULL || parentdifferent)) { + dp->i_nlink--; + dp->i_flag |= ICHG; + } + if (dirremove()) { + ip->i_nlink--; + ip->i_flag |= ICHG; + } + if (error == 0) /* conservative */ + error = u.u_error; + } + irele(ip); + if (dp) + iput(dp); + + /* + * 4) Renaming a directory with the parent + * different requires ".." to be rewritten. + * The window is still there for ".." to + * be inconsistent, but this is unavoidable, + * and a lot shorter than when it was done + * in a user process. + */ + if (doingdirectory && parentdifferent && error == 0) { + struct dirtemplate dirbuf; + + u.u_dirp = uap->to; + ip = namei(uchar, LOOKUP | LOCKPARENT, 0); + if (ip == NULL) { + printf("rename: .. went away\n"); + return; + } + dp = u.u_pdir; + if ((ip->i_mode&IFMT) != IFDIR) { + printf("rename: .. not a directory\n"); + goto stuck; + } + error = rdwri(UIO_READ, ip, (caddr_t)&dirbuf, + sizeof (struct dirtemplate), (off_t)0, 1, (int *)0); + if (error == 0) { + dirbuf.dotdot_ino = dp->i_number; + (void) rdwri(UIO_WRITE, ip, (caddr_t)&dirbuf, + sizeof (struct dirtemplate), (off_t)0, 1, (int *)0); + } +stuck: + irele(dp); + iput(ip); + } + goto done; + +bad: + iput(dp); +bad1: + if (xp) + iput(xp); +out: + ip->i_nlink--; + ip->i_flag |= ICHG; + irele(ip); +done: + if (error) + u.u_error = error; } /* - * Common code for mount and umount. - * Check that the user's argument is a reasonable - * thing on which to mount, and return the device number if so. + * Make a new file. */ -dev_t -getmdev() +struct inode * +maknode(mode) + int mode; { - dev_t dev; register struct inode *ip; + ino_t ipref; - if (!suser()) - return(NODEV); - ip = namei(uchar, 0); - if(ip == NULL) - return(NODEV); - if((ip->i_mode&IFMT) != IFBLK) - u.u_error = ENOTBLK; - dev = (dev_t)ip->i_un.i_rdev; - if(major(dev) >= nblkdev) - u.u_error = ENXIO; - iput(ip); - return(dev); + if ((mode & IFMT) == IFDIR) + ipref = dirpref(u.u_pdir->i_fs); + else + ipref = u.u_pdir->i_number; + ip = ialloc(u.u_pdir, ipref, mode); + if (ip == NULL) { + iput(u.u_pdir); + return (NULL); + } +#ifdef QUOTA + if (ip->i_dquot != NODQUOT) + panic("maknode: dquot"); +#endif + ip->i_flag |= IACC|IUPD|ICHG; + if ((mode & IFMT) == 0) + mode |= IFREG; + ip->i_mode = mode & ~u.u_cmask; + ip->i_nlink = 1; + ip->i_uid = u.u_uid; + ip->i_gid = u.u_pdir->i_gid; + if (ip->i_mode & ISGID && !groupmember(ip->i_gid)) + ip->i_mode &= ~ISGID; +#ifdef QUOTA + ip->i_dquot = inoquota(ip); +#endif + + /* + * Make sure inode goes to disk before directory entry. + */ + iupdat(ip, &time, &time, 1); + u.u_error = direnter(ip); + if (u.u_error) { + /* + * Write error occurred trying to update directory + * so must deallocate the inode. + */ + ip->i_nlink = 0; + ip->i_flag |= ICHG; + iput(ip); + return (NULL); + } + return (ip); }