projects / unix-history / blob
? search:
summary | tags | clone url | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
initialize i_diroff; proper association of indirect blocks
[unix-history] / usr / src / sys / ufs / ufs / ufs_inode.c
/*
* Copyright (c) 1982, 1986, 1989 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* @(#)ufs_inode.c 7.27 (Berkeley) %G%
*/
#include "param.h"
#include "systm.h"
#include "mount.h"
#include "user.h"
#include "proc.h"
#include "file.h"
#include "buf.h"
#include "cmap.h"
#include "vnode.h"
#include "../ufs/inode.h"
#include "../ufs/fs.h"
#include "../ufs/ufsmount.h"
#ifdef QUOTA
#include "../ufs/quota.h"
#endif
#include "kernel.h"
#include "malloc.h"
#define INOHSZ 512
#if ((INOHSZ&(INOHSZ-1)) == 0)
#define INOHASH(dev,ino) (((dev)+(ino))&(INOHSZ-1))
#else
#define INOHASH(dev,ino) (((unsigned)((dev)+(ino)))%INOHSZ)
#endif
union ihead {
union ihead *ih_head[2];
struct inode *ih_chain[2];
} ihead[INOHSZ];
int prtactive; /* 1 => print out reclaim of active vnodes */
/*
* Initialize hash links for inodes.
*/
ufs_init()
{
register int i;
register union ihead *ih = ihead;
#ifndef lint
if (VN_MAXPRIVATE < sizeof(struct inode))
panic("ihinit: too small");
#endif /* not lint */
for (i = INOHSZ; --i >= 0; ih++) {
ih->ih_head[0] = ih;
ih->ih_head[1] = ih;
}
}
/*
* Look up an vnode/inode by device,inumber.
* If it is in core (in the inode structure),
* honor the locking protocol.
* If it is not in core, read it in from the
* specified device.
* Callers must check for mount points!!
* In all cases, a pointer to a locked
* inode structure is returned.
*/
iget(xp, ino, ipp)
struct inode *xp;
ino_t ino;
struct inode **ipp;
{
dev_t dev = xp->i_dev;
struct mount *mntp = ITOV(xp)->v_mount;
register struct fs *fs = VFSTOUFS(mntp)->um_fs;
extern struct vnodeops ufs_vnodeops, spec_inodeops;
register struct inode *ip, *iq;
register struct vnode *vp;
struct vnode *nvp;
struct buf *bp;
struct dinode *dp;
union ihead *ih;
int error;
ih = &ihead[INOHASH(dev, ino)];
loop:
for (ip = ih->ih_chain[0]; ip != (struct inode *)ih; ip = ip->i_forw) {
if (ino != ip->i_number || dev != ip->i_dev)
continue;
if ((ip->i_flag&ILOCKED) != 0) {
ip->i_flag |= IWANT;
sleep((caddr_t)ip, PINOD);
goto loop;
}
if (vget(ITOV(ip)))
goto loop;
*ipp = ip;
return(0);
}
/*
* Allocate a new inode.
*/
if (error = getnewvnode(VT_UFS, mntp, &ufs_vnodeops, &nvp)) {
*ipp = 0;
return (error);
}
ip = VTOI(nvp);
ip->i_vnode = nvp;
ip->i_flag = 0;
ip->i_devvp = 0;
ip->i_mode = 0;
ip->i_diroff = 0;
#ifdef QUOTA
ip->i_dquot = NODQUOT;
#endif
/*
* Put it onto its hash chain and lock it so that other requests for
* this inode will block if they arrive while we are sleeping waiting
* for old data structures to be purged or for the contents of the
* disk portion of this inode to be read.
*/
ip->i_dev = dev;
ip->i_number = ino;
insque(ip, ih);
ILOCK(ip);
/*
* Read in the disk contents for the inode.
*/
if (error = bread(VFSTOUFS(mntp)->um_devvp, fsbtodb(fs, itod(fs, ino)),
(int)fs->fs_bsize, NOCRED, &bp)) {
/*
* Unlock and discard unneeded inode.
*/
iput(ip);
brelse(bp);
*ipp = 0;
return (error);
}
dp = bp->b_un.b_dino;
dp += itoo(fs, ino);
ip->i_din = *dp;
brelse(bp);
/*
* Initialize the associated vnode
*/
vp = ITOV(ip);
vp->v_type = IFTOVT(ip->i_mode);
if (vp->v_type == VCHR || vp->v_type == VBLK) {
vp->v_op = &spec_inodeops;
if (nvp = checkalias(vp, ip->i_rdev, mntp)) {
/*
* Reinitialize aliased inode.
*/
vp = nvp;
iq = VTOI(vp);
iq->i_vnode = vp;
iq->i_flag = 0;
ILOCK(iq);
iq->i_din = ip->i_din;
iq->i_dev = dev;
iq->i_number = ino;
insque(iq, ih);
/*
* Discard unneeded vnode
*/
ip->i_mode = 0;
iput(ip);
ip = iq;
}
}
if (ino == ROOTINO)
vp->v_flag |= VROOT;
/*
* Finish inode initialization.
*/
ip->i_fs = fs;
ip->i_devvp = VFSTOUFS(mntp)->um_devvp;
VREF(ip->i_devvp);
#ifdef QUOTA
if (ip->i_mode != 0)
ip->i_dquot = inoquota(ip);
#endif
/*
* Set up a generation number for this inode if it does not
* already have one. This should only happen on old filesystems.
*/
if (ip->i_gen == 0) {
if (++nextgennumber < (u_long)time.tv_sec)
nextgennumber = time.tv_sec;
ip->i_gen = nextgennumber;
if ((vp->v_mount->m_flag & M_RDONLY) == 0)
ip->i_flag |= IMOD;
}
*ipp = ip;
return (0);
}
/*
* Unlock and decrement the reference count of an inode structure.
*/
iput(ip)
register struct inode *ip;
{
if ((ip->i_flag & ILOCKED) == 0)
panic("iput");
IUNLOCK(ip);
vrele(ITOV(ip));
}
/*
* Last reference to an inode, write the inode out and if necessary,
* truncate and deallocate the file.
*/
ufs_inactive(vp)
struct vnode *vp;
{
register struct inode *ip = VTOI(vp);
int mode, error = 0;
if (prtactive && vp->v_usecount != 0)
vprint("ufs_inactive: pushing active", vp);
/*
* Get rid of inodes related to stale file handles.
*/
if (ip->i_mode == 0) {
if ((vp->v_flag & VXLOCK) == 0)
vgone(vp);
return (0);
}
ILOCK(ip);
if (ip->i_nlink <= 0 && (vp->v_mount->m_flag & M_RDONLY) == 0) {
error = itrunc(ip, (u_long)0, 0);
mode = ip->i_mode;
ip->i_mode = 0;
ip->i_rdev = 0;
ip->i_flag |= IUPD|ICHG;
ifree(ip, ip->i_number, mode);
#ifdef QUOTA
(void) chkiq(ip->i_dev, ip, ip->i_uid, 0);
dqrele(ip->i_dquot);
ip->i_dquot = NODQUOT;
#endif
}
IUPDAT(ip, &time, &time, 0);
/*
* If we are done with the inode, reclaim it
* so that it can be reused immediately.
*/
if (vp->v_usecount == 0 && ip->i_mode == 0) {
vinvalbuf(vp, 0);
IUNLOCK(ip);
ip->i_flag = 0;
if ((vp->v_flag & VXLOCK) == 0)
vgone(vp);
return (error);
}
IUNLOCK(ip);
ip->i_flag = 0;
return (error);
}
/*
* Reclaim an inode so that it can be used for other purposes.
*/
ufs_reclaim(vp)
register struct vnode *vp;
{
register struct inode *ip = VTOI(vp);
if (prtactive && vp->v_usecount != 0)
vprint("ufs_reclaim: pushing active", vp);
/*
* Remove the inode from its hash chain.
*/
remque(ip);
ip->i_forw = ip;
ip->i_back = ip;
/*
* Purge old data structures associated with the inode.
*/
cache_purge(vp);
if (ip->i_devvp) {
vrele(ip->i_devvp);
ip->i_devvp = 0;
}
#ifdef QUOTA
dqrele(ip->i_dquot);
ip->i_dquot = NODQUOT;
#endif
ip->i_flag = 0;
return (0);
}
/*
* Check accessed and update flags on an inode structure.
* If any is on, update the inode with the current time.
* If waitfor is given, then must ensure I/O order,
* so wait for write to complete.
*/
iupdat(ip, ta, tm, waitfor)
register struct inode *ip;
struct timeval *ta, *tm;
int waitfor;
{
struct buf *bp;
struct vnode *vp = ITOV(ip);
struct dinode *dp;
register struct fs *fs;
fs = ip->i_fs;
if ((ip->i_flag & (IUPD|IACC|ICHG|IMOD)) == 0)
return (0);
if (vp->v_mount->m_flag & M_RDONLY)
return (0);
error = bread(ip->i_devvp, fsbtodb(fs, itod(fs, ip->i_number)),
(int)fs->fs_bsize, NOCRED, &bp);
if (error) {
brelse(bp);
return (error);
}
if (ip->i_flag&IACC)
ip->i_atime = ta->tv_sec;
if (ip->i_flag&IUPD)
ip->i_mtime = tm->tv_sec;
if (ip->i_flag&ICHG)
ip->i_ctime = time.tv_sec;
ip->i_flag &= ~(IUPD|IACC|ICHG|IMOD);
dp = bp->b_un.b_dino + itoo(fs, ip->i_number);
*dp = ip->i_din;
if (waitfor) {
return (bwrite(bp));
} else {
bdwrite(bp);
return (0);
}
}
#define SINGLE 0 /* index of single indirect block */
#define DOUBLE 1 /* index of double indirect block */
#define TRIPLE 2 /* index of triple indirect block */
/*
* Truncate the inode ip to at most length size. Free affected disk
* blocks -- the blocks of the file are removed in reverse order.
*
* NB: triple indirect blocks are untested.
*/
itrunc(oip, length, flags)
register struct inode *oip;
u_long length;
int flags;
{
register daddr_t lastblock;
daddr_t bn, lbn, lastiblock[NIADDR];
register struct fs *fs;
register struct inode *ip;
struct buf *bp;
int offset, osize, size, level;
long count, nblocks, blocksreleased = 0;
register int i;
int aflags, error, allerror;
struct inode tip;
if (oip->i_size <= length) {
oip->i_flag |= ICHG|IUPD;
error = iupdat(oip, &time, &time, 1);
return (error);
}
/*
* Calculate index into inode's block list of
* last direct and indirect blocks (if any)
* which we want to keep. Lastblock is -1 when
* the file is truncated to 0.
*/
fs = oip->i_fs;
lastblock = lblkno(fs, length + fs->fs_bsize - 1) - 1;
lastiblock[SINGLE] = lastblock - NDADDR;
lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
nblocks = btodb(fs->fs_bsize);
/*
* Update the size of the file. If the file is not being
* truncated to a block boundry, the contents of the
* partial block following the end of the file must be
* zero'ed in case it ever become accessable again because
* of subsequent file growth.
*/
osize = oip->i_size;
offset = blkoff(fs, length);
if (offset == 0) {
oip->i_size = length;
} else {
lbn = lblkno(fs, length);
aflags = B_CLRBUF;
if (flags & IO_SYNC)
aflags |= B_SYNC;
if (error = balloc(oip, lbn, offset, &bp, aflags))
return (error);
oip->i_size = length;
size = blksize(fs, oip, lbn);
bn = bp->b_blkno;
count = howmany(size, CLBYTES);
munhash(oip->i_devvp, bn + i * CLBYTES / DEV_BSIZE);
bzero(bp->b_un.b_addr + offset, (unsigned)(size - offset));
brealloc(bp, size);
if (flags & IO_SYNC)
bwrite(bp);
else
bdwrite(bp);
}
/*
* Update file and block pointers
* on disk before we start freeing blocks.
* If we crash before free'ing blocks below,
* the blocks will be returned to the free list.
* lastiblock values are also normalized to -1
* for calls to indirtrunc below.
*/
tip = *oip;
tip.i_size = osize;
for (level = TRIPLE; level >= SINGLE; level--)
if (lastiblock[level] < 0) {
oip->i_ib[level] = 0;
lastiblock[level] = -1;
}
for (i = NDADDR - 1; i > lastblock; i--)
oip->i_db[i] = 0;
oip->i_flag |= ICHG|IUPD;
vinvalbuf(ITOV(oip), (length > 0));
allerror = iupdat(oip, &time, &time, MNT_WAIT);
/*
* Indirect blocks first.
*/
ip = &tip;
for (level = TRIPLE; level >= SINGLE; level--) {
bn = ip->i_ib[level];
if (bn != 0) {
error = indirtrunc(ip, bn, lastiblock[level], level,
&count);
if (error)
allerror = error;
blocksreleased += count;
if (lastiblock[level] < 0) {
ip->i_ib[level] = 0;
blkfree(ip, bn, (off_t)fs->fs_bsize);
blocksreleased += nblocks;
}
}
if (lastiblock[level] >= 0)
goto done;
}
/*
* All whole direct blocks or frags.
*/
for (i = NDADDR - 1; i > lastblock; i--) {
register off_t bsize;
bn = ip->i_db[i];
if (bn == 0)
continue;
ip->i_db[i] = 0;
bsize = (off_t)blksize(fs, ip, i);
blkfree(ip, bn, bsize);
blocksreleased += btodb(bsize);
}
if (lastblock < 0)
goto done;
/*
* Finally, look for a change in size of the
* last direct block; release any frags.
*/
bn = ip->i_db[lastblock];
if (bn != 0) {
off_t oldspace, newspace;
/*
* Calculate amount of space we're giving
* back as old block size minus new block size.
*/
oldspace = blksize(fs, ip, lastblock);
ip->i_size = length;
newspace = blksize(fs, ip, lastblock);
if (newspace == 0)
panic("itrunc: newspace");
if (oldspace - newspace > 0) {
/*
* Block number of space to be free'd is
* the old block # plus the number of frags
* required for the storage we're keeping.
*/
bn += numfrags(fs, newspace);
blkfree(ip, bn, oldspace - newspace);
blocksreleased += btodb(oldspace - newspace);
}
}
done:
/* BEGIN PARANOIA */
for (level = SINGLE; level <= TRIPLE; level++)
if (ip->i_ib[level] != oip->i_ib[level])
panic("itrunc1");
for (i = 0; i < NDADDR; i++)
if (ip->i_db[i] != oip->i_db[i])
panic("itrunc2");
/* END PARANOIA */
oip->i_blocks -= blocksreleased;
if (oip->i_blocks < 0) /* sanity */
oip->i_blocks = 0;
oip->i_flag |= ICHG;
#ifdef QUOTA
(void) chkdq(oip, -blocksreleased, 0);
#endif
return (allerror);
}
/*
* Release blocks associated with the inode ip and
* stored in the indirect block bn. Blocks are free'd
* in LIFO order up to (but not including) lastbn. If
* level is greater than SINGLE, the block is an indirect
* block and recursive calls to indirtrunc must be used to
* cleanse other indirect blocks.
*
* NB: triple indirect blocks are untested.
*/
indirtrunc(ip, bn, lastbn, level, countp)
register struct inode *ip;
daddr_t bn, lastbn;
int level;
long *countp;
{
register int i;
struct buf *bp;
register struct fs *fs = ip->i_fs;
register daddr_t *bap;
daddr_t *copy, nb, last;
long blkcount, factor;
int nblocks, blocksreleased = 0;
int error, allerror = 0;
/*
* Calculate index in current block of last
* block to be kept. -1 indicates the entire
* block so we need not calculate the index.
*/
factor = 1;
for (i = SINGLE; i < level; i++)
factor *= NINDIR(fs);
last = lastbn;
if (lastbn > 0)
last /= factor;
nblocks = btodb(fs->fs_bsize);
/*
* Get buffer of block pointers, zero those
* entries corresponding to blocks to be free'd,
* and update on disk copy first.
*/
#ifdef SECSIZE
bp = bread(ip->i_dev, fsbtodb(fs, bn), (int)fs->fs_bsize,
fs->fs_dbsize);
#else SECSIZE
error = bread(ip->i_devvp, fsbtodb(fs, bn), (int)fs->fs_bsize,
NOCRED, &bp);
if (error) {
brelse(bp);
*countp = 0;
return (error);
}
bap = bp->b_un.b_daddr;
MALLOC(copy, daddr_t *, fs->fs_bsize, M_TEMP, M_WAITOK);
bcopy((caddr_t)bap, (caddr_t)copy, (u_int)fs->fs_bsize);
bzero((caddr_t)&bap[last + 1],
(u_int)(NINDIR(fs) - (last + 1)) * sizeof (daddr_t));
if (last == -1)
bp->b_flags |= B_INVAL;
error = bwrite(bp);
if (error)
allerror = error;
bap = copy;
/*
* Recursively free totally unused blocks.
*/
for (i = NINDIR(fs) - 1; i > last; i--) {
nb = bap[i];
if (nb == 0)
continue;
if (level > SINGLE) {
error = indirtrunc(ip, nb, (daddr_t)-1, level - 1,
&blkcount);
if (error)
allerror = error;
blocksreleased += blkcount;
}
blkfree(ip, nb, (off_t)fs->fs_bsize);
blocksreleased += nblocks;
}
/*
* Recursively free last partial block.
*/
if (level > SINGLE && lastbn >= 0) {
last = lastbn % factor;
nb = bap[i];
if (nb != 0) {
error = indirtrunc(ip, nb, last, level - 1, &blkcount);
if (error)
allerror = error;
blocksreleased += blkcount;
}
}
FREE(copy, M_TEMP);
*countp = blocksreleased;
return (allerror);
}
/*
* Lock an inode. If its already locked, set the WANT bit and sleep.
*/
ilock(ip)
register struct inode *ip;
{
while (ip->i_flag & ILOCKED) {
ip->i_flag |= IWANT;
if (ip->i_spare0 == u.u_procp->p_pid)
panic("locking against myself");
ip->i_spare1 = u.u_procp->p_pid;
(void) sleep((caddr_t)ip, PINOD);
}
ip->i_spare1 = 0;
ip->i_spare0 = u.u_procp->p_pid;
u.u_spare[0]++;
ip->i_flag |= ILOCKED;
}
/*
* Unlock an inode. If WANT bit is on, wakeup.
*/
iunlock(ip)
register struct inode *ip;
{
if ((ip->i_flag & ILOCKED) == 0)
vprint("iunlock: unlocked inode", ITOV(ip));
ip->i_spare0 = 0;
u.u_spare[0]--;
ip->i_flag &= ~ILOCKED;
if (ip->i_flag&IWANT) {
ip->i_flag &= ~IWANT;
wakeup((caddr_t)ip);
}
}
/*
* Check mode permission on inode pointer. Mode is READ, WRITE or EXEC.
* The mode is shifted to select the owner/group/other fields. The
* super user is granted all permissions.
*
* NB: Called from vnode op table. It seems this could all be done
* using vattr's but...
*/
iaccess(ip, mode, cred)
register struct inode *ip;
register int mode;
struct ucred *cred;
{
register gid_t *gp;
int i;
/*
* If you're the super-user, you always get access.
*/
if (cred->cr_uid == 0)
return (0);
/*
* Access check is based on only one of owner, group, public.
* If not owner, then check group. If not a member of the
* group, then check public access.
*/
if (cred->cr_uid != ip->i_uid) {
mode >>= 3;
gp = cred->cr_groups;
for (i = 0; i < cred->cr_ngroups; i++, gp++)
if (ip->i_gid == *gp)
goto found;
mode >>= 3;
found:
;
}
if ((ip->i_mode & mode) != 0)
return (0);
return (EACCES);
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.