dbraun@cadavr.intel.com (Doug Braun ~) (12/22/88)
#!/bin/sh
#
#Run this file through sh to get:
# xfs.c
echo -n 'Extracting xfs.c ... '
sed 's/^X//' > xfs.c << 'EOF_xfs.c'
X
X/**************************************************
XUZI (Unix Z80 Implementation) Utilities: xfs.c
X***************************************************/
X
X
X/*LINTLIBRARY*/
X#include "unix.h"
X#include "extern.h"
X
Xchar *bread();
X
X
X
Xxfs_init(bootdev)
Xint bootdev;
X{
X register char *j;
X inoptr i_open();
X
X fs_init();
X bufinit();
X
X /* User's file table */
X for (j=udata.u_files; j < (udata.u_files+UFTSIZE); ++j)
X *j = -1;
X
X /* Open the console tty device */
X if (d_open(TTYDEV) != 0)
X panic("no tty");
X
X ROOTDEV = bootdev;
X
X /* Mount the root device */
X if (fmount(ROOTDEV,NULLINODE))
X panic("no filesys");
X
X ifnot (root = i_open(ROOTDEV,ROOTINODE))
X panic("no root");
X i_ref(udata.u_cwd = root);
X rdtime(&udata.u_time);
X}
X
X
Xxfs_end()
X{
X register int16 j;
X
X for (j=0; j < UFTSIZE; ++j)
X {
X ifnot (udata.u_files[j] & 0x80) /* Portable equivalent of == -1 */
X doclose(j);
X }
X
X _sync(); /* Not necessary, but a good idea. */
X
X}
X
X
X
X_open(name, flag)
Xchar *name;
Xregister int16 flag;
X{
X int16 uindex;
X register int16 oftindex;
X register inoptr ino;
X register int16 perm;
X inoptr n_open();
X
X udata.u_error = 0;
X
X if (flag < 0 || flag > 2)
X {
X udata.u_error = EINVAL;
X return (-1);
X }
X if ((uindex = uf_alloc()) == -1)
X return (-1);
X
X if ((oftindex = oft_alloc()) == -1)
X goto nooft;
X
X ifnot (ino = n_open(name,NULLINOPTR))
X goto cantopen;
X
X of_tab[oftindex].o_inode = ino;
X
X perm = getperm(ino);
X if (((flag == O_RDONLY || flag == O_RDWR) && !(perm & OTH_RD)) ||
X ((flag == O_WRONLY || flag == O_RDWR) && !(perm & OTH_WR)))
X {
X udata.u_error = EPERM;
X goto cantopen;
X }
X
X if (getmode(ino) == F_DIR &&
X (flag == O_WRONLY || flag == O_RDWR))
X {
X udata.u_error = EISDIR;
X goto cantopen;
X }
X
X if (isdevice(ino) && d_open((int)ino->c_node.i_addr[0]) != 0)
X {
X udata.u_error = ENXIO;
X goto cantopen;
X }
X
X udata.u_files[uindex] = oftindex;
X
X of_tab[oftindex].o_ptr.o_offset = 0;
X of_tab[oftindex].o_ptr.o_blkno = 0;
X of_tab[oftindex].o_access = flag;
X
X return (uindex);
X
Xcantopen:
X oft_deref(oftindex); /* This will call i_deref() */
Xnooft:
X udata.u_files[uindex] = -1;
X return (-1);
X}
X
X
X
X
X_close(uindex)
Xint16 uindex;
X{
X udata.u_error = 0;
X return(doclose(uindex));
X}
X
X
X
Xdoclose(uindex)
Xint16 uindex;
X{
X register int16 oftindex;
X inoptr ino;
X inoptr getinode();
X
X udata.u_error = 0;
X ifnot(ino = getinode(uindex))
X return(-1);
X oftindex = udata.u_files[uindex];
X
X if (isdevice(ino)
X /* && ino->c_refs == 1 && of_tab[oftindex].o_refs == 1 */ )
X d_close((int)(ino->c_node.i_addr[0]));
X
X udata.u_files[uindex] = -1;
X oft_deref(oftindex);
X
X return(0);
X}
X
X
X
X_creat(name, mode)
Xchar *name;
Xint16 mode;
X{
X register inoptr ino;
X register int16 uindex;
X register int16 oftindex;
X inoptr parent;
X register int16 j;
X inoptr n_open();
X inoptr newfile();
X
X udata.u_error = 0;
X parent = NULLINODE;
X
X if ((uindex = uf_alloc()) == -1)
X return (-1);
X if ((oftindex = oft_alloc()) == -1)
X return (-1);
X
X if (ino = n_open(name,&parent)) /* The file exists */
X {
X i_deref(parent);
X if (getmode(ino) == F_DIR)
X {
X i_deref(ino);
X udata.u_error = EISDIR;
X goto nogood;
X }
X ifnot (getperm(ino) & OTH_WR)
X {
X i_deref(ino);
X udata.u_error = EACCES;
X goto nogood;
X }
X if (getmode(ino) == F_REG)
X {
X /* Truncate the file to zero length */
X f_trunc(ino);
X /* Reset any oft pointers */
X for (j=0; j < OFTSIZE; ++j)
X if (of_tab[j].o_inode == ino)
X of_tab[j].o_ptr.o_blkno = of_tab[j].o_ptr.o_offset = 0;
X }
X
X }
X else
X {
X if (parent && (ino = newfile(parent,name)))
X /* Parent was derefed in newfile */
X {
X ino->c_node.i_mode = (F_REG | (mode & MODE_MASK & ~udata.u_mask));
X setftime(ino, A_TIME|M_TIME|C_TIME);
X /* The rest of the inode is initialized in newfile() */
X wr_inode(ino);
X }
X else
X {
X /* Doesn't exist and can't make it */
X if (parent)
X i_deref(parent);
X goto nogood;
X }
X }
X
X udata.u_files[uindex] = oftindex;
X
X of_tab[oftindex].o_ptr.o_offset = 0;
X of_tab[oftindex].o_ptr.o_blkno = 0;
X of_tab[oftindex].o_inode = ino;
X of_tab[oftindex].o_access = O_WRONLY;
X
X return (uindex);
X
Xnogood:
X oft_deref(oftindex);
X return (-1);
X
X}
X
X
X
X
X_link(name1, name2)
Xchar *name1;
Xchar *name2;
X{
X register inoptr ino;
X register inoptr ino2;
X inoptr parent2;
X char *filename();
X inoptr n_open();
X
X udata.u_error = 0;
X ifnot (ino = n_open(name1,NULLINOPTR))
X return(-1);
X
X if (getmode(ino) == F_DIR && !super())
X {
X udata.u_error = EPERM;
X goto nogood;
X }
X
X /* Make sure file2 doesn't exist, and get its parent */
X if (ino2 = n_open(name2,&parent2))
X {
X i_deref(ino2);
X i_deref(parent2);
X udata.u_error = EEXIST;
X goto nogood;
X }
X
X ifnot (parent2)
X goto nogood;
X
X if (ino->c_dev != parent2->c_dev)
X {
X i_deref(parent2);
X udata.u_error = EXDEV;
X goto nogood;
X }
X
X if (ch_link(parent2,"",filename(name2),ino) == 0)
X goto nogood;
X
X
X /* Update the link count. */
X ++ino->c_node.i_nlink;
X wr_inode(ino);
X setftime(ino, C_TIME);
X
X i_deref(parent2);
X i_deref(ino);
X return(0);
X
Xnogood:
X i_deref(ino);
X return(-1);
X
X}
X
X
X
X_unlink(path)
Xchar *path;
X{
X register inoptr ino;
X inoptr pino;
X char *filename();
X inoptr i_open();
X inoptr n_open();
X
X udata.u_error = 0;
X ino = n_open(path,&pino);
X
X ifnot (pino && ino)
X {
X udata.u_error = ENOENT;
X return (-1);
X }
X
X if (getmode(ino) == F_DIR && !super())
X {
X udata.u_error = EPERM;
X goto nogood;
X }
X
X /* Remove the directory entry */
X
X if (ch_link(pino,filename(path),"",NULLINODE) == 0)
X goto nogood;
X
X /* Decrease the link count of the inode */
X
X ifnot (ino->c_node.i_nlink--)
X {
X ino->c_node.i_nlink += 2;
X warning("_unlink: bad nlink");
X }
X setftime(ino, C_TIME);
X i_deref(pino);
X i_deref(ino);
X return(0);
X
Xnogood:
X i_deref(pino);
X i_deref(ino);
X return(-1);
X}
X
X
X
X
X_read(d, buf, nbytes)
Xint16 d;
Xchar *buf;
Xuint16 nbytes;
X{
X register inoptr ino;
X inoptr rwsetup();
X
X udata.u_error = 0;
X /* Set up u_base, u_offset, ino; check permissions, file num. */
X if ((ino = rwsetup(1, d, buf, nbytes)) == NULLINODE)
X return (-1); /* bomb out if error */
X
X readi(ino);
X updoff(d);
X
X return (udata.u_count);
X}
X
X
X
X_write(d, buf, nbytes)
Xint16 d;
Xchar *buf;
Xuint16 nbytes;
X{
X register inoptr ino;
X off_t *offp;
X inoptr rwsetup();
X
X udata.u_error = 0;
X /* Set up u_base, u_offset, ino; check permissions, file num. */
X if ((ino = rwsetup(0, d, buf, nbytes)) == NULLINODE)
X return (-1); /* bomb out if error */
X
X writei(ino);
X updoff(d);
X
X return (udata.u_count);
X}
X
X
X
Xinoptr
Xrwsetup(rwflag, d, buf, nbytes)
Xint rwflag;
Xint d;
Xchar *buf;
Xint nbytes;
X{
X register inoptr ino;
X register struct oft *oftp;
X inoptr getinode();
X
X udata.u_base = buf;
X udata.u_count = nbytes;
X
X if ((ino = getinode(d)) == NULLINODE)
X return (NULLINODE);
X
X oftp = of_tab + udata.u_files[d];
X if (oftp->o_access == (rwflag ? O_WRONLY : O_RDONLY))
X {
X udata.u_error = EBADF;
X return (NULLINODE);
X }
X
X setftime(ino, rwflag ? A_TIME : (A_TIME | M_TIME | C_TIME));
X
X /* Initialize u_offset from file pointer */
X udata.u_offset.o_blkno = oftp->o_ptr.o_blkno;
X udata.u_offset.o_offset = oftp->o_ptr.o_offset;
X
X return (ino);
X}
X
X
X
Xreadi(ino)
Xregister inoptr ino;
X{
X register uint16 amount;
X register uint16 toread;
X register blkno_t pblk;
X register char *bp;
X int dev;
X int ispipe;
X char *bread();
X char *zerobuf();
X blkno_t bmap();
X
X dev = ino->c_dev;
X ispipe = 0;
X switch (getmode(ino))
X {
X
X case F_DIR:
X case F_REG:
X
X /* See of end of file will limit read */
X toread = udata.u_count =
X ino->c_node.i_size.o_blkno-udata.u_offset.o_blkno >= 64 ?
X udata.u_count :
X min(udata.u_count,
X 512*(ino->c_node.i_size.o_blkno-udata.u_offset.o_blkno) +
X (ino->c_node.i_size.o_offset-udata.u_offset.o_offset));
X goto loop;
X
X case F_BDEV:
X toread = udata.u_count;
X dev = *(ino->c_node.i_addr);
X
X loop:
X while (toread)
X {
X if ((pblk = bmap(ino, udata.u_offset.o_blkno, 1)) != NULLBLK)
X bp = bread(dev, pblk, 0);
X else
X bp = zerobuf();
X
X bcopy(bp+udata.u_offset.o_offset, udata.u_base,
X (amount = min(toread, 512 - udata.u_offset.o_offset)));
X brelse(bp);
X
X udata.u_base += amount;
X addoff(&udata.u_offset, amount);
X if (ispipe && udata.u_offset.o_blkno >= 18)
X udata.u_offset.o_blkno = 0;
X toread -= amount;
X }
X
X break;
X
X case F_CDEV:
X udata.u_count = cdread(ino->c_node.i_addr[0]);
X
X if (udata.u_count != -1)
X addoff(&udata.u_offset, udata.u_count);
X break;
X
X default:
X udata.u_error = ENODEV;
X }
X}
X
X
X
X/* Writei (and readi) need more i/o error handling */
X
Xwritei(ino)
Xregister inoptr ino;
X{
X register uint16 amount;
X register uint16 towrite;
X register char *bp;
X int ispipe;
X blkno_t pblk;
X int created; /* Set by bmap if newly allocated block used */
X int dev;
X char *zerobuf();
X char *bread();
X blkno_t bmap();
X
X dev = ino->c_dev;
X
X switch (getmode(ino))
X {
X
X case F_BDEV:
X dev = *(ino->c_node.i_addr);
X case F_DIR:
X case F_REG:
X ispipe = 0;
X towrite = udata.u_count;
X goto loop;
X
X loop:
X
X while (towrite)
X {
X amount = min(towrite, 512 - udata.u_offset.o_offset);
X
X
X if ((pblk = bmap(ino, udata.u_offset.o_blkno, 0)) == NULLBLK)
X break; /* No space to make more blocks */
X
X /* If we are writing an entire block, we don't care
X about its previous contents */
X bp = bread(dev, pblk, (amount == 512));
X
X bcopy(udata.u_base, bp+udata.u_offset.o_offset, amount);
X bawrite(bp);
X
X udata.u_base += amount;
X addoff(&udata.u_offset, amount);
X towrite -= amount;
X }
X
X /* Update size if file grew */
X ifnot (ispipe)
X {
X if ( udata.u_offset.o_blkno > ino->c_node.i_size.o_blkno ||
X (udata.u_offset.o_blkno == ino->c_node.i_size.o_blkno &&
X udata.u_offset.o_offset > ino->c_node.i_size.o_offset))
X {
X ino->c_node.i_size.o_blkno = udata.u_offset.o_blkno;
X ino->c_node.i_size.o_offset = udata.u_offset.o_offset;
X ino->c_dirty = 1;
X }
X }
X
X break;
X
X case F_CDEV:
X udata.u_count = cdwrite(ino->c_node.i_addr[0]);
X
X if (udata.u_count != -1)
X addoff(&udata.u_offset, udata.u_count);
X break;
X
X default:
X udata.u_error = ENODEV;
X }
X
X}
X
X
Xmin(a, b)
Xint a, b;
X{
X return ( a < b ? a : b);
X}
X
X
Xpsize(ino)
Xinoptr ino;
X{
X return (512*ino->c_node.i_size.o_blkno+ino->c_node.i_size.o_offset);
X}
X
X
X
Xaddoff(ofptr, amount)
Xoff_t *ofptr;
Xint amount;
X{
X if (amount >= 0)
X {
X ofptr->o_offset += amount % 512;
X if (ofptr->o_offset >= 512)
X {
X ofptr->o_offset -= 512;
X ++ofptr->o_blkno;
X }
X ofptr->o_blkno += amount/512;
X }
X else
X {
X ofptr->o_offset -= (-amount) % 512;
X if (ofptr->o_offset < 0)
X {
X ofptr->o_offset += 512;
X --ofptr->o_blkno;
X }
X ofptr->o_blkno -= (-amount)/512;
X }
X}
X
X
Xupdoff(d)
Xint d;
X{
X register off_t *offp;
X
X /* Update current file pointer */
X offp = &of_tab[udata.u_files[d]].o_ptr;
X offp->o_blkno = udata.u_offset.o_blkno;
X offp->o_offset = udata.u_offset.o_offset;
X}
X
X
X
X_seek(file,offset,flag)
Xint16 file;
Xuint16 offset;
Xint16 flag;
X{
X register inoptr ino;
X register int16 oftno;
X register uint16 retval;
X inoptr getinode();
X
X udata.u_error = 0;
X if ((ino = getinode(file)) == NULLINODE)
X return(-1);
X
X oftno = udata.u_files[file];
X
X
X if (flag <= 2)
X retval = of_tab[oftno].o_ptr.o_offset;
X else
X retval = of_tab[oftno].o_ptr.o_blkno;
X
X switch(flag)
X {
X case 0:
X of_tab[oftno].o_ptr.o_blkno = 0;
X of_tab[oftno].o_ptr.o_offset = offset;
X break;
X case 1:
X of_tab[oftno].o_ptr.o_offset += offset;
X break;
X case 2:
X of_tab[oftno].o_ptr.o_blkno = ino->c_node.i_size.o_blkno;
X of_tab[oftno].o_ptr.o_offset = ino->c_node.i_size.o_offset + offset;
X break;
X case 3:
X of_tab[oftno].o_ptr.o_blkno = offset;
X break;
X case 4:
X of_tab[oftno].o_ptr.o_blkno += offset;
X break;
X case 5:
X of_tab[oftno].o_ptr.o_blkno = ino->c_node.i_size.o_blkno + offset;
X break;
X default:
X udata.u_error = EINVAL;
X return(-1);
X }
X
X while ((unsigned)of_tab[oftno].o_ptr.o_offset >= 512)
X {
X of_tab[oftno].o_ptr.o_offset -= 512;
X ++of_tab[oftno].o_ptr.o_blkno;
X }
X
X return((int16)retval);
X}
X
X
X
X
X_chdir(dir)
Xchar *dir;
X{
X register inoptr newcwd;
X inoptr n_open();
X
X udata.u_error = 0;
X ifnot (newcwd = n_open(dir,NULLINOPTR))
X return(-1);
X
X if (getmode(newcwd) != F_DIR)
X {
X udata.u_error = ENOTDIR;
X i_deref(newcwd);
X return(-1);
X }
X i_deref(udata.u_cwd);
X udata.u_cwd = newcwd;
X return(0);
X}
X
X
X
X
X_mknod(name,mode,dev)
Xchar *name;
Xint16 mode;
Xint16 dev;
X{
X register inoptr ino;
X inoptr parent;
X inoptr n_open();
X inoptr newfile();
X
X udata.u_error = 0;
X ifnot (super())
X {
X udata.u_error = EPERM;
X return(-1);
X }
X
X if (ino = n_open(name,&parent))
X {
X udata.u_error = EEXIST;
X goto nogood;
X }
X
X ifnot (parent)
X {
X udata.u_error = ENOENT;
X return(-1);
X }
X
X ifnot (ino = newfile(parent,name))
X goto nogood2;
X
X /* Initialize mode and dev */
X ino->c_node.i_mode = mode & ~udata.u_mask;
X ino->c_node.i_addr[0] = isdevice(ino) ? dev : 0;
X setftime(ino, A_TIME|M_TIME|C_TIME);
X wr_inode(ino);
X
X i_deref(ino);
X return (0);
X
Xnogood:
X i_deref(ino);
Xnogood2:
X i_deref(parent);
X return (-1);
X}
X
X
X
X
X_sync()
X{
X register j;
X register inoptr ino;
X register char *buf;
X char *bread();
X
X /* Write out modified inodes */
X
X udata.u_error = 0;
X for (ino=i_tab; ino < i_tab+ITABSIZE; ++ino)
X if ((ino->c_refs) > 0 && ino->c_dirty != 0)
X {
X wr_inode(ino);
X ino->c_dirty = 0;
X }
X
X /* Write out modified super blocks */
X /* This fills the rest of the super block with garbage. */
X
X for (j=0; j < NDEVS; ++j)
X {
X if (fs_tab[j].s_mounted == SMOUNTED && fs_tab[j].s_fmod)
X {
X fs_tab[j].s_fmod = 0;
X buf = bread(j, 1, 1);
X bcopy((char *)&fs_tab[j], buf, 512);
X bfree(buf, 2);
X }
X }
X
X bufsync(); /* Clear buffer pool */
X}
X
X
X_access(path,mode)
Xchar *path;
Xint16 mode;
X{
X register inoptr ino;
X register int16 euid;
X register int16 egid;
X register int16 retval;
X inoptr n_open();
X
X udata.u_error = 0;
X if ((mode & 07) && !*(path))
X {
X udata.u_error = ENOENT;
X return (-1);
X }
X
X /* Temporarily make eff. id real id. */
X euid = udata.u_euid;
X egid = udata.u_egid;
X udata.u_euid = udata.u_ptab->p_uid;
X udata.u_egid = udata.u_gid;
X
X ifnot (ino = n_open(path,NULLINOPTR))
X {
X retval = -1;
X goto nogood;
X }
X
X retval = 0;
X if (~getperm(ino) & (mode&07))
X {
X udata.u_error = EPERM;
X retval = -1;
X }
X
X i_deref(ino);
Xnogood:
X udata.u_euid = euid;
X udata.u_egid = egid;
X
X return(retval);
X}
X
X
X_chmod(path,mode)
Xchar *path;
Xint16 mode;
X{
X
X inoptr ino;
X inoptr n_open();
X
X udata.u_error = 0;
X ifnot (ino = n_open(path,NULLINOPTR))
X return (-1);
X
X if (ino->c_node.i_uid != udata.u_euid && !super())
X {
X i_deref(ino);
X udata.u_error = EPERM;
X return(-1);
X }
X
X ino->c_node.i_mode = (mode & MODE_MASK) | (ino->c_node.i_mode & F_MASK);
X setftime(ino, C_TIME);
X i_deref(ino);
X return(0);
X}
X
X
X
X
X_chown(path, owner, group)
Xchar *path;
Xint owner;
Xint group;
X{
X register inoptr ino;
X inoptr n_open();
X
X udata.u_error = 0;
X ifnot (ino = n_open(path,NULLINOPTR))
X return (-1);
X
X if (ino->c_node.i_uid != udata.u_euid && !super())
X {
X i_deref(ino);
X udata.u_error = EPERM;
X return(-1);
X }
X
X ino->c_node.i_uid = owner;
X ino->c_node.i_gid = group;
X setftime(ino, C_TIME);
X i_deref(ino);
X return(0);
X}
X
X
X
X
X_stat(path,buf)
Xchar *path;
Xchar *buf;
X{
X
X register inoptr ino;
X inoptr n_open();
X
X udata.u_error = 0;
X ifnot (valadr(buf,sizeof(struct stat)) && (ino = n_open(path,NULLINOPTR)))
X {
X return (-1);
X }
X
X stcpy(ino,buf);
X i_deref(ino);
X return(0);
X}
X
X
X
X
X_fstat(fd, buf)
Xint16 fd;
Xchar *buf;
X{
X register inoptr ino;
X inoptr getinode();
X
X udata.u_error = 0;
X ifnot (valadr(buf,sizeof(struct stat)))
X return(-1);
X
X if ((ino = getinode(fd)) == NULLINODE)
X return(-1);
X
X stcpy(ino,buf);
X return(0);
X}
X
X
X
X/* Utility for stat and fstat */
Xstcpy(ino, buf)
Xinoptr ino;
Xchar *buf;
X{
X /* violently system-dependent */
X bcopy((char *)&(ino->c_dev), buf, 12);
X bcopy((char *)&(ino->c_node.i_addr[0]), buf+12, 2);
X bcopy((char *)&(ino->c_node.i_size), buf+14, 16);
X}
X
X
X
X_dup(oldd)
Xint16 oldd;
X{
X register int newd;
X inoptr getinode();
X
X udata.u_error = 0;
X if (getinode(oldd) == NULLINODE)
X return(-1);
X
X if ((newd = uf_alloc()) == -1)
X return (-1);
X
X udata.u_files[newd] = udata.u_files[oldd];
X ++of_tab[udata.u_files[oldd]].o_refs;
X
X return(newd);
X}
X
X
X
X
X_dup2(oldd, newd)
Xint16 oldd;
Xint16 newd;
X{
X inoptr getinode();
X
X udata.u_error = 0;
X if (getinode(oldd) == NULLINODE)
X return(-1);
X
X if (newd < 0 || newd >= UFTSIZE)
X {
X udata.u_error = EBADF;
X return (-1);
X }
X
X ifnot (udata.u_files[newd] & 0x80)
X doclose(newd);
X
X udata.u_files[newd] = udata.u_files[oldd];
X ++of_tab[udata.u_files[oldd]].o_refs;
X
X return(0);
X}
X
X
X
X
X_umask(mask)
Xint mask;
X{
X register int omask;
X
X udata.u_error = 0;
X omask = udata.u_mask;
X udata.u_mask = mask & 0777;
X return(omask);
X}
X
X
X
X
X/* Special system call returns super-block of given
Xfilesystem for users to determine free space, etc.
XShould be replaced with a sync() followed by a read
Xof block 1 of the device. */
X
X_getfsys(dev,buf)
X{
X udata.u_error = 0;
X if (dev < 0 || dev >= NDEVS || fs_tab[dev].s_mounted != SMOUNTED)
X {
X udata.u_error = ENXIO;
X return(-1);
X }
X
X bcopy((char *)&fs_tab[dev],(char *)buf,sizeof(struct filesys));
X return(0);
X}
X
X
X
X_ioctl(fd, request, data)
Xint fd;
Xint request;
Xchar *data;
X{
X
X register inoptr ino;
X register int dev;
X inoptr getinode();
X
X udata.u_error = 0;
X if ((ino = getinode(fd)) == NULLINODE)
X return(-1);
X
X ifnot (isdevice(ino))
X {
X udata.u_error = ENOTTY;
X return(-1);
X }
X
X ifnot (getperm(ino) & OTH_WR)
X {
X udata.u_error = EPERM;
X return(-1);
X }
X
X dev = ino->c_node.i_addr[0];
X
X if (d_ioctl(dev, request,data))
X return(-1);
X return(0);
X}
X
X
X
X
X_mount(spec, dir, rwflag)
Xchar *spec;
Xchar *dir;
Xint rwflag;
X{
X register inoptr sino, dino;
X register int dev;
X inoptr n_open();
X
X udata.u_error = 0;
X ifnot(super())
X {
X udata.u_error = EPERM;
X return (-1);
X }
X
X ifnot (sino = n_open(spec,NULLINOPTR))
X return (-1);
X
X ifnot (dino = n_open(dir,NULLINOPTR))
X {
X i_deref(sino);
X return (-1);
X }
X
X if (getmode(sino) != F_BDEV)
X {
X udata.u_error = ENOTBLK;
X goto nogood;
X }
X
X if (getmode(dino) != F_DIR)
X {
X udata.u_error = ENOTDIR;
X goto nogood;
X }
X
X dev = (int)sino->c_node.i_addr[0];
X
X if ( dev >= NDEVS || d_open(dev))
X {
X udata.u_error = ENXIO;
X goto nogood;
X }
X
X if (fs_tab[dev].s_mounted || dino->c_refs != 1 || dino->c_num == ROOTINODE)
X {
X udata.u_error = EBUSY;
X goto nogood;
X }
X
X _sync();
X
X if (fmount(dev,dino))
X {
X udata.u_error = EBUSY;
X goto nogood;
X }
X
X i_deref(dino);
X i_deref(sino);
X return(0);
X
Xnogood:
X i_deref(dino);
X i_deref(sino);
X return (-1);
X}
X
X
X
X
X_umount(spec)
Xchar *spec;
X{
X register inoptr sino;
X register int dev;
X register inoptr ptr;
X inoptr n_open();
X
X udata.u_error = 0;
X ifnot(super())
X {
X udata.u_error = EPERM;
X return (-1);
X }
X
X ifnot (sino = n_open(spec,NULLINOPTR))
X return (-1);
X
X if (getmode(sino) != F_BDEV)
X {
X udata.u_error = ENOTBLK;
X goto nogood;
X }
X
X dev = (int)sino->c_node.i_addr[0];
X ifnot (validdev(dev))
X {
X udata.u_error = ENXIO;
X goto nogood;
X }
X
X if (!fs_tab[dev].s_mounted)
X {
X udata.u_error = EINVAL;
X goto nogood;
X }
X
X for (ptr = i_tab; ptr < i_tab+ITABSIZE; ++ptr)
X if (ptr->c_refs > 0 && ptr->c_dev == dev)
X {
X udata.u_error = EBUSY;
X goto nogood;
X }
X
X _sync();
X fs_tab[dev].s_mounted = 0;
X i_deref(fs_tab[dev].s_mntpt);
X
X i_deref(sino);
X return(0);
X
Xnogood:
X i_deref(sino);
X return (-1);
X}
X
X
X
X
X
X_time(tvec)
Xint tvec[];
X{
X udata.u_error = 0;
X rdtime(tvec); /* In machdep.c */
X return(0);
X}
X
X
X
X
X
X
X
X
X
X
X
X
X/* N_open is given a string containing a path name,
X and returns a inode table pointer. If it returns NULL,
X the file did not exist. If the parent existed,
X and parent is not null, parent will be filled in with
X the parents inoptr. Otherwise, parent will be set to NULL. */
X
Xinoptr
Xn_open(name,parent)
Xregister char *name;
Xregister inoptr *parent;
X{
X
X register inoptr wd; /* the directory we are currently searching. */
X register inoptr ninode;
X register inoptr temp;
X inoptr srch_dir();
X inoptr srch_mt();
X
X if (*name == '/')
X wd = root;
X else
X wd = udata.u_cwd;
X
X i_ref(ninode = wd);
X i_ref(ninode);
X
X for(;;)
X {
X if (ninode)
X magic(ninode);
X
X /* See if we are at a mount point */
X if (ninode)
X ninode = srch_mt(ninode);
X
X while (*name == '/') /* Skip (possibly repeated) slashes */
X ++name;
X ifnot (*name) /* No more components of path? */
X break;
X ifnot (ninode)
X {
X udata.u_error = ENOENT;
X goto nodir;
X }
X i_deref(wd);
X wd = ninode;
X if (getmode(wd) != F_DIR)
X {
X udata.u_error = ENOTDIR;
X goto nodir;
X }
X ifnot (getperm(wd) & OTH_EX)
X {
X udata.u_error = EPERM;
X goto nodir;
X }
X
X /* See if we are going up through a mount point */
X if ( wd->c_num == ROOTINODE && wd->c_dev != ROOTDEV && name[1] == '.')
X {
X temp = fs_tab[wd->c_dev].s_mntpt;
X ++temp->c_refs;
X i_deref(wd);
X wd = temp;
X }
X
X ninode = srch_dir(wd,name);
X
X while (*name != '/' && *name )
X ++name;
X }
X
X if (parent)
X *parent = wd;
X else
X i_deref(wd);
X ifnot (parent || ninode)
X udata.u_error = ENOENT;
X return (ninode);
X
Xnodir:
X if (parent)
X *parent = NULLINODE;
X i_deref(wd);
X return(NULLINODE);
X
X}
X
X
X
X/* Srch_dir is given a inode pointer of an open directory
Xand a string containing a filename, and searches the directory
Xfor the file. If it exists, it opens it and returns the inode pointer,
Xotherwise NULL. This depends on the fact that ba_read will return unallocated
Xblocks as zero-filled, and a partially allocated block will be padded with
Xzeroes. */
X
Xinoptr
Xsrch_dir(wd,compname)
Xregister inoptr wd;
Xregister char *compname;
X{
X register int curentry;
X register blkno_t curblock;
X register struct direct *buf;
X register int nblocks;
X unsigned inum;
X inoptr i_open();
X blkno_t bmap();
X
X nblocks = wd->c_node.i_size.o_blkno;
X if (wd->c_node.i_size.o_offset)
X ++nblocks;
X
X for (curblock=0; curblock < nblocks; ++curblock)
X {
X buf = (struct direct *)bread( wd->c_dev, bmap(wd, curblock, 1), 0);
X for (curentry = 0; curentry < 32; ++curentry)
X {
X if (namecomp(compname,buf[curentry].d_name))
X {
X inum = buf[curentry&0x1f].d_ino;
X brelse(buf);
X return(i_open(wd->c_dev, inum));
X }
X }
X brelse(buf);
X }
X return(NULLINODE);
X}
X
X
X
X/* Srch_mt sees if the given inode is a mount point. If
Xso it dereferences it, and references and returns a pointer
Xto the root of the mounted filesystem. */
X
Xinoptr
Xsrch_mt(ino)
Xregister inoptr ino;
X{
X register int j;
X inoptr i_open();
X
X for (j=0; j < NDEVS; ++j)
X if (fs_tab[j].s_mounted == SMOUNTED && fs_tab[j].s_mntpt == ino)
X {
X i_deref(ino);
X return(i_open(j,ROOTINODE));
X }
X
X return(ino);
X}
X
X
X/* I_open is given an inode number and a device number,
Xand makes an entry in the inode table for them, or
Xincreases it reference count if it is already there.
XAn inode # of zero means a newly allocated inode */
X
Xinoptr
Xi_open(dev,ino)
Xregister int dev;
Xregister unsigned ino;
X{
X
X struct dinode *buf;
X register inoptr nindex;
X int i;
X register inoptr j;
X int new;
X static nexti = i_tab;
X unsigned i_alloc();
X
X if (dev<0 || dev>=NDEVS)
X panic("i_open: Bad dev");
X
X new = 0;
X ifnot (ino) /* Want a new one */
X {
X new = 1;
X ifnot (ino = i_alloc(dev))
X {
X udata.u_error = ENOSPC;
X return (NULLINODE);
X }
X }
X
X if (ino < ROOTINODE || ino >= (fs_tab[dev].s_isize-2)*8)
X {
X warning("i_open: bad inode number");
X return (NULLINODE);
X }
X
X
X nindex = NULLINODE;
X j = nexti;
X for (i=0; i < ITABSIZE; ++i)
X {
X nexti =j;
X if (++j >= i_tab+ITABSIZE)
X j = i_tab;
X
X ifnot (j->c_refs)
X nindex = j;
X
X if (j->c_dev == dev && j->c_num == ino)
X {
X nindex = j;
X goto found;
X }
X }
X
X /* Not already in table. */
X
X ifnot (nindex) /* No unrefed slots in inode table */
X {
X udata.u_error = ENFILE;
X return(NULLINODE);
X }
X
X buf = (struct dinode *)bread(dev, (ino>>3)+2, 0);
X bcopy((char *)&(buf[ino & 0x07]), (char *)&(nindex->c_node), 64);
X brelse(buf);
X
X nindex->c_dev = dev;
X nindex->c_num = ino;
X nindex->c_magic = CMAGIC;
X
Xfound:
X if (new)
X {
X if (nindex->c_node.i_nlink || nindex->c_node.i_mode & F_MASK)
X goto badino;
X }
X else
X {
X ifnot (nindex->c_node.i_nlink && nindex->c_node.i_mode & F_MASK)
X goto badino;
X }
X
X ++nindex->c_refs;
X return(nindex);
X
Xbadino:
X warning("i_open: bad disk inode");
X return (NULLINODE);
X}
X
X
X
X/* Ch_link modifies or makes a new entry in the directory for the name
Xand inode pointer given. The directory is searched for oldname.
XWhen found, it is changed to newname, and it inode # is that of
X*nindex. A oldname of "" matches a unused slot, and a nindex
Xof NULLINODE means an inode # of 0. A return status of 0 means there
Xwas no space left in the filesystem, or a non-empty oldname was not found,
Xor the user did not have write permission. */
X
Xch_link(wd,oldname,newname,nindex)
Xregister inoptr wd;
Xchar *oldname;
Xchar *newname;
Xinoptr nindex;
X{
X struct direct curentry;
X
X ifnot (getperm(wd) & OTH_WR)
X {
X udata.u_error = EPERM;
X return (0);
X }
X
X /* Search the directory for the desired slot. */
X
X udata.u_offset.o_blkno = 0;
X udata.u_offset.o_offset = 0;
X
X for (;;)
X {
X udata.u_count = 16;
X udata.u_base = (char *)&curentry;
X readi(wd);
X
X /* Read until EOF or name is found */
X /* readi() advances udata.u_offset */
X if (udata.u_count == 0 || namecomp(oldname, curentry.d_name))
X break;
X }
X
X if (udata.u_count == 0 && *oldname)
X return (0); /* Entry not found */
X
X bcopy(newname, curentry.d_name, 14);
X if (nindex)
X curentry.d_ino = nindex->c_num;
X else
X curentry.d_ino = 0;
X
X /* If an existing slot is being used, we must back up the file offset */
X if (udata.u_count)
X {
X ifnot (udata.u_offset.o_offset)
X {
X --udata.u_offset.o_blkno;
X udata.u_offset.o_offset = 512;
X }
X udata.u_offset.o_offset -= 16;
X }
X
X udata.u_count = 16;
X udata.u_base = (char *)&curentry;
X writei(wd);
X
X if (udata.u_error)
X return (0);
X
X setftime(wd, A_TIME|M_TIME|C_TIME); /* Sets c_dirty */
X
X /* Update file length to next block */
X if (wd->c_node.i_size.o_offset)
X {
X wd->c_node.i_size.o_offset = 0;
X ++wd->c_node.i_size.o_blkno;
X }
X
X return (1);
X}
X
X
X
X/* Filename is given a path name, and returns a pointer
Xto the final component of it. */
X
Xchar *
Xfilename(path)
Xchar *path;
X{
X register char *ptr;
X
X ptr = path;
X while (*ptr)
X ++ptr;
X while (*ptr != '/' && ptr-- > path)
X ;
X return (ptr+1);
X}
X
X
X/* Namecomp compares two strings to see if they are the same file name.
XIt stops at 14 chars or a null or a slash. It returns 0 for difference. */
X
Xnamecomp(n1,n2)
Xregister char *n1;
Xregister char *n2;
X{
X register int n;
X
X n = 14;
X while (*n1 && *n1 != '/')
X {
X if (*n1++ != *n2++)
X return(0);
X ifnot (--n)
X return(-1);
X }
X return(*n2 == '\0' || *n2 == '/');
X}
X
X
X
X/* Newfile is given a pointer to a directory and a name, and
X creates an entry in the directory for the name, dereferences
X the parent, and returns a pointer to the new inode.
X It allocates an inode number,
X and creates a new entry in the inode table for the new file,
X and initializes the inode table entry for the new file. The new file
X will have one reference, and 0 links to it.
X Better make sure there isn't already an entry with the same name. */
X
Xinoptr
Xnewfile(pino, name)
Xregister inoptr pino;
Xregister char *name;
X{
X
X register inoptr nindex;
X register int j;
X inoptr i_open();
X
X ifnot (nindex = i_open(pino->c_dev, 0))
X goto nogood;
X
X nindex->c_node.i_mode = F_REG; /* For the time being */
X nindex->c_node.i_nlink = 1;
X nindex->c_node.i_size.o_offset = 0;
X nindex->c_node.i_size.o_blkno = 0;
X for (j=0; j <20; j++)
X nindex->c_node.i_addr[j] = 0;
X wr_inode(nindex);
X
X ifnot (ch_link(pino,"",filename(name),nindex))
X {
X i_deref(nindex);
X goto nogood;
X }
X
X i_deref (pino);
X return(nindex);
X
Xnogood:
X i_deref (pino);
X return (NULLINODE);
X}
X
X
X
X/* Check the given device number, and return its address in the mount table.
XAlso time-stamp the superblock of dev, and mark it modified.
XUsed when freeing and allocating blocks and inodes. */
X
Xfsptr
Xgetdev(devno)
Xregister int devno;
X{
X register fsptr dev;
X
X dev = fs_tab + devno;
X if (devno < 0 || devno >= NDEVS || !dev->s_mounted)
X panic("getdev: bad dev");
X rdtime(&(dev->s_time));
X dev->s_fmod = 1;
X return (dev);
X}
X
X
X/* Returns true if the magic number of a superblock is corrupt */
X
Xbaddev(dev)
Xfsptr dev;
X{
X return (dev->s_mounted != SMOUNTED);
X}
X
X
X/* I_alloc finds an unused inode number, and returns it,
Xor 0 if there are no more inodes available. */
X
Xunsigned
Xi_alloc(devno)
Xint devno;
X{
X fsptr dev;
X blkno_t blk;
X struct dinode *buf;
X register int j;
X register int k;
X unsigned ino;
X
X if (baddev(dev = getdev(devno)))
X goto corrupt;
X
Xtryagain:
X if (dev->s_ninode)
X {
X ifnot (dev->s_tinode)
X goto corrupt;
X ino = dev->s_inode[--dev->s_ninode];
X if (ino < 2 || ino >= (dev->s_isize-2)*8)
X goto corrupt;
X --dev->s_tinode;
X return(ino);
X }
X
X /* We must scan the inodes, and fill up the table */
X
X _sync(); /* Make on-disk inodes consistent */
X k = 0;
X for (blk = 2; blk < dev->s_isize; blk++)
X {
X buf = (struct dinode *)bread(devno, blk, 0);
X for (j=0; j < 8; j++)
X {
X ifnot (buf[j].i_mode || buf[j].i_nlink)
X dev->s_inode[k++] = 8*(blk-2) + j;
X if (k==50)
X {
X brelse(buf);
X goto done;
X }
X }
X brelse(buf);
X }
X
Xdone:
X ifnot (k)
X {
X if (dev->s_tinode)
X goto corrupt;
X udata.u_error = ENOSPC;
X return(0);
X }
X
X dev->s_ninode = k;
X goto tryagain;
X
Xcorrupt:
X warning("i_alloc: corrupt superblock");
X dev->s_mounted = 1;
X udata.u_error = ENOSPC;
X return(0);
X}
X
X
X/* I_free is given a device and inode number,
Xand frees the inode. It is assumed that there
Xare no references to the inode in the inode table or
Xin the filesystem. */
X
Xi_free(devno, ino)
Xregister int devno;
Xregister unsigned ino;
X{
X register fsptr dev;
X
X if (baddev(dev = getdev(devno)))
X return;
X
X if (ino < 2 || ino >= (dev->s_isize-2)*8)
X panic("i_free: bad ino");
X
X ++dev->s_tinode;
X if (dev->s_ninode < 50)
X dev->s_inode[dev->s_ninode++] = ino;
X}
X
X
X/* Blk_alloc is given a device number, and allocates an unused block
Xfrom it. A returned block number of zero means no more blocks. */
X
Xblkno_t
Xblk_alloc(devno)
Xregister int devno;
X{
X
X register fsptr dev;
X register blkno_t newno;
X blkno_t *buf;
X register int j;
X
X if (baddev(dev = getdev(devno)))
X goto corrupt2;
X
X if (dev->s_nfree <= 0 || dev->s_nfree > 50)
X goto corrupt;
X
X newno = dev->s_free[--dev->s_nfree];
X ifnot (newno)
X {
X if (dev->s_tfree != 0)
X goto corrupt;
X udata.u_error = ENOSPC;
X ++dev->s_nfree;
X return(0);
X }
X
X /* See if we must refill the s_free array */
X
X ifnot (dev->s_nfree)
X {
X buf = (blkno_t *)bread(devno,newno, 0);
X dev->s_nfree = buf[0];
X for (j=0; j < 50; j++)
X {
X dev->s_free[j] = buf[j+1];
X }
X brelse((char *)buf);
X }
X
X validblk(devno, newno);
X
X ifnot (dev->s_tfree)
X goto corrupt;
X --dev->s_tfree;
X
X /* Zero out the new block */
X buf = bread(devno, newno, 2);
X bzero(buf, 512);
X bawrite(buf);
X return(newno);
X
Xcorrupt:
X warning("blk_alloc: corrupt");
X dev->s_mounted = 1;
Xcorrupt2:
X udata.u_error = ENOSPC;
X return(0);
X}
X
X
X/* Blk_free is given a device number and a block number,
Xand frees the block. */
X
Xblk_free(devno,blk)
Xregister int devno;
Xregister blkno_t blk;
X{
X register fsptr dev;
X register char *buf;
X
X ifnot (blk)
X return;
X
X if (baddev(dev = getdev(devno)))
X return;
X
X validblk(devno, blk);
X
X if (dev->s_nfree == 50)
X {
X buf = bread(devno, blk, 1);
X bcopy((char *)&(dev->s_nfree), buf, 512);
X bawrite(buf);
X dev->s_nfree = 0;
X }
X
X ++dev->s_tfree;
X dev->s_free[(dev->s_nfree)++] = blk;
X
X}
X
X
X
X
X/* Oft_alloc and oft_deref allocate and dereference (and possibly free)
Xentries in the open file table. */
X
Xoft_alloc()
X{
X register int j;
X
X for (j=0; j < OFTSIZE ; ++j)
X {
X ifnot (of_tab[j].o_refs)
X {
X of_tab[j].o_refs = 1;
X of_tab[j].o_inode = NULLINODE;
X return (j);
X }
X }
X udata.u_error = ENFILE;
X return(-1);
X}
X
Xoft_deref(of)
Xregister int of;
X{
X register struct oft *ofptr;
X
X ofptr = of_tab + of;
X
X if (!(--ofptr->o_refs) && ofptr->o_inode)
X {
X i_deref(ofptr->o_inode);
X ofptr->o_inode = NULLINODE;
X }
X}
X
X
X
X/* Uf_alloc finds an unused slot in the user file table. */
X
Xuf_alloc()
X{
X register int j;
X
X for (j=0; j < UFTSIZE ; ++j)
X {
X if (udata.u_files[j] & 0x80) /* Portable, unlike == -1 */
X {
X return (j);
X }
X }
X udata.u_error = ENFILE;
X return(-1);
X}
X
X
X
X/* I_ref increases the reference count of the given inode table entry. */
X
Xi_ref(ino)
Xinoptr ino;
X{
X if (++(ino->c_refs) == 2*ITABSIZE) /* Arbitrary limit. */
X panic("too many i-refs");
X}
X
X
X/* I_deref decreases the reference count of an inode, and frees it
Xfrom the table if there are no more references to it. If it also
Xhas no links, the inode itself and its blocks (if not a device) is freed. */
X
Xi_deref(ino)
Xregister inoptr ino;
X{
X magic(ino);
X
X ifnot (ino->c_refs)
X panic("inode freed.");
X
X /* If the inode has no links and no refs, it must have
X its blocks freed. */
X
X ifnot (--ino->c_refs || ino->c_node.i_nlink)
X f_trunc(ino);
X
X /* If the inode was modified, we must write it to disk. */
X if (!(ino->c_refs) && ino->c_dirty)
X {
X ifnot (ino->c_node.i_nlink)
X {
X ino->c_node.i_mode = 0;
X i_free(ino->c_dev, ino->c_num);
X }
X wr_inode(ino);
X }
X}
X
X
X/* Wr_inode writes out the given inode in the inode table out to disk,
Xand resets its dirty bit. */
X
Xwr_inode(ino)
Xregister inoptr ino;
X{
X struct dinode *buf;
X register blkno_t blkno;
X
X magic(ino);
X
X blkno = (ino->c_num >> 3) + 2;
X buf = (struct dinode *)bread(ino->c_dev, blkno,0);
X bcopy((char *)(&ino->c_node),
X (char *)((char **)&buf[ino->c_num & 0x07]), 64);
X bfree(buf, 2);
X ino->c_dirty = 0;
X}
X
X
X/* isdevice(ino) returns true if ino points to a device */
Xisdevice(ino)
Xinoptr ino;
X{
X return (ino->c_node.i_mode & 020000);
X}
X
X
X/* This returns the device number of an inode representing a device */
Xdevnum(ino)
Xinoptr ino;
X{
X return (*(ino->c_node.i_addr));
X}
X
X
X/* F_trunc frees all the blocks associated with the file,
Xif it is a disk file. */
X
Xf_trunc(ino)
Xregister inoptr ino;
X{
X int dev;
X int j;
X
X dev = ino->c_dev;
X
X /* First deallocate the double indirect blocks */
X freeblk(dev, ino->c_node.i_addr[19], 2);
X
X /* Also deallocate the indirect blocks */
X freeblk(dev, ino->c_node.i_addr[18], 1);
X
X /* Finally, free the direct blocks */
X for (j=17; j >= 0; --j)
X freeblk(dev, ino->c_node.i_addr[j], 0);
X
X bzero((char *)ino->c_node.i_addr, sizeof(ino->c_node.i_addr));
X
X ino->c_dirty = 1;
X ino->c_node.i_size.o_blkno = 0;
X ino->c_node.i_size.o_offset = 0;
X}
X
X
X/* Companion function to f_trunc(). */
Xfreeblk(dev, blk, level)
Xint dev;
Xblkno_t blk;
Xint level;
X{
X blkno_t *buf;
X int j;
X
X ifnot (blk)
X return;
X
X if (level)
X {
X buf = (blkno_t *)bread(dev, blk, 0);
X for (j=255; j >= 0; --j)
X freeblk(dev, buf[j], level-1);
X brelse((char *)buf);
X }
X
X blk_free(dev,blk);
X}
X
X
X
X/* Changes: blk_alloc zeroes block it allocates */
X
X/*
X * Bmap defines the structure of file system storage
X * by returning the physical block number on a device given the
X * inode and the logical block number in a file.
X * The block is zeroed if created.
X */
Xblkno_t
Xbmap(ip, bn, rwflg)
Xinoptr ip;
Xregister blkno_t bn;
Xint rwflg;
X{
X register int i;
X register bufptr bp;
X register int j;
X register blkno_t nb;
X int sh;
X int dev;
X
X blkno_t blk_alloc();
X
X if (getmode(ip) == F_BDEV)
X return (bn);
X
X dev = ip->c_dev;
X
X /*
X * blocks 0..17 are direct blocks
X */
X if(bn < 18) {
X nb = ip->c_node.i_addr[bn];
X if(nb == 0) {
X if(rwflg || (nb = blk_alloc(dev))==0)
X return(NULLBLK);
X ip->c_node.i_addr[bn] = nb;
X ip->c_dirty = 1;
X }
X return(nb);
X }
X
X /*
X * addresses 18 and 19
X * have single and double indirect blocks.
X * the first step is to determine
X * how many levels of indirection.
X */
X bn -= 18;
X sh = 0;
X j = 2;
X if (bn & 0xff00) /* bn > 255 so double indirect */
X {
X sh = 8;
X bn -= 256;
X j = 1;
X }
X
X /*
X * fetch the address from the inode
X * Create the first indirect block if needed.
X */
X ifnot (nb = ip->c_node.i_addr[20-j])
X {
X if(rwflg || !(nb = blk_alloc(dev)))
X return(NULLBLK);
X ip->c_node.i_addr[20-j] = nb;
X ip->c_dirty = 1;
X }
X
X /*
X * fetch through the indirect blocks
X */
X for(; j<=2; j++) {
X bp = (bufptr)bread(dev, nb, 0);
X /******
X if(bp->bf_error) {
X brelse(bp);
X return((blkno_t)0);
X }
X ******/
X i = (bn>>sh) & 0xff;
X if (nb = ((blkno_t *)bp)[i])
X brelse(bp);
X else
X {
X if(rwflg || !(nb = blk_alloc(dev))) {
X brelse(bp);
X return(NULLBLK);
X }
X ((blkno_t *)bp)[i] = nb;
X bawrite(bp);
X }
X sh -= 8;
X }
X
X return(nb);
X}
X
X
X
X/* Validblk panics if the given block number is not a valid data block
Xfor the given device. */
X
Xvalidblk(dev, num)
Xint dev;
Xblkno_t num;
X{
X register fsptr devptr;
X
X devptr = fs_tab + dev;
X
X if (devptr->s_mounted == 0)
X panic("validblk: not mounted");
X
X if (num < devptr->s_isize || num >= devptr->s_fsize)
X panic("validblk: invalid blk");
X}
X
X
X
X/* This returns the inode pointer associated with a user's
Xfile descriptor, checking for valid data structures */
X
Xinoptr
Xgetinode(uindex)
Xregister int uindex;
X{
X register int oftindex;
X register inoptr inoindex;
X
X if (uindex < 0 || uindex >= UFTSIZE || udata.u_files[uindex] & 0x80 )
X {
X udata.u_error = EBADF;
X return (NULLINODE);
X }
X
X if ((oftindex = udata.u_files[uindex]) < 0 || oftindex >= OFTSIZE)
X panic("Getinode: bad desc table");
X
X if ((inoindex = of_tab[oftindex].o_inode) < i_tab ||
X inoindex >= i_tab+ITABSIZE)
X panic("Getinode: bad OFT");
X
X magic(inoindex);
X
X return(inoindex);
X}
X
X/* Super returns true if we are the superuser */
Xsuper()
X{
X return(udata.u_euid == 0);
X}
X
X/* Getperm looks at the given inode and the effective user/group ids, and
Xreturns the effective permissions in the low-order 3 bits. */
X
Xgetperm(ino)
Xinoptr ino;
X{
X int mode;
X
X if (super())
X return(07);
X
X mode = ino->c_node.i_mode;
X if (ino->c_node.i_uid == udata.u_euid)
X mode >>= 6;
X else if (ino->c_node.i_gid == udata.u_egid)
X mode >>= 3;
X
X return(mode & 07);
X}
X
X
X/* This sets the times of the given inode, according to the flags */
X
Xsetftime(ino, flag)
Xregister inoptr ino;
Xregister int flag;
X{
X ino->c_dirty = 1;
X
X if (flag & A_TIME)
X rdtime(&(ino->c_node.i_atime));
X if (flag & M_TIME)
X rdtime(&(ino->c_node.i_mtime));
X if (flag & C_TIME)
X rdtime(&(ino->c_node.i_ctime));
X}
X
X
Xgetmode(ino)
Xinoptr ino;
X{
X return( ino->c_node.i_mode & F_MASK);
X}
X
X
X/* Fmount places the given device in the mount table with
Xmount point ino */
X
Xfmount(dev,ino)
Xregister int dev;
Xregister inoptr ino;
X{
X char *buf;
X register struct filesys *fp;
X
X if (d_open(dev) != 0)
X panic("fmount: Cant open filesystem");
X /* Dev 0 blk 1 */
X fp = fs_tab + dev;
X buf = bread(dev, 1, 0);
X bcopy(buf, (char *)fp, sizeof(struct filesys));
X brelse(buf);
X
X /* See if there really is a filesystem on the device */
X if (fp->s_mounted != SMOUNTED ||
X fp->s_isize >= fp->s_fsize)
X return (-1);
X
X fp->s_mntpt = ino;
X if (ino)
X ++ino->c_refs;
X
X return (0);
X}
X
X
Xmagic(ino)
Xinoptr ino;
X{
X if (ino->c_magic != CMAGIC)
X panic("Corrupt inode");
X}
EOF_xfs.c
echo 'Done'
exit 0
Doug Braun Intel Corp CAD
408 765-4279
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