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new fs system calls prior to truncate and rename
[unix-history] / usr / src / sys / ufs / ufs / ufs_inode.c
/* ufs_inode.c 4.23 82/08/10 */
#include "../h/param.h"
#include "../h/systm.h"
#include "../h/mount.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/inode.h"
#include "../h/fs.h"
#include "../h/conf.h"
#include "../h/buf.h"
#include "../h/inline.h"
#ifdef QUOTA
#include "../h/quota.h"
#endif
#define INOHSZ 63
#if ((INOHSZ&(INOHSZ-1)) == 0)
#define INOHASH(dev,ino) (((dev)+(ino))&(INOHSZ-1))
#else
#define INOHASH(dev,ino) (((dev)+(ino))%INOHSZ)
#endif
union ihead { /* inode LRU cache, Chris Maltby */
union ihead *ih_head[2];
struct inode *ih_chain[2];
} ihead[INOHSZ];
struct inode *ifreeh, **ifreet;
/*
* Initialize hash links for inodes
* and build inode free list.
*/
ihinit()
{
register int i;
register struct inode *ip = inode;
register union ihead *ih = ihead;
for (i = INOHSZ; --i >= 0; ih++) {
ih->ih_head[0] = ih;
ih->ih_head[1] = ih;
}
ifreeh = ip;
ifreet = &ip->i_freef;
ip->i_freeb = &ifreeh;
ip->i_forw = ip;
ip->i_back = ip;
for (i = ninode; --i > 0; ) {
++ip;
ip->i_forw = ip;
ip->i_back = ip;
*ifreet = ip;
ip->i_freeb = ifreet;
ifreet = &ip->i_freef;
}
ip->i_freef = NULL;
}
#ifdef notdef
/*
* Find an inode if it is incore.
* This is the equivalent, for inodes,
* of ``incore'' in bio.c or ``pfind'' in subr.c.
*/
struct inode *
ifind(dev, ino)
dev_t dev;
ino_t ino;
{
register struct inode *ip;
register union ihead *ih;
ih = &ihead[INOHASH(dev, ino)];
for (ip = ih->ih_chain[0]; ip != (struct inode *)ih; ip = ip->i_forw)
if (ino==ip->i_number && dev==ip->i_dev)
return (ip);
return ((struct inode *)0);
}
#endif notdef
/*
* Look up an 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.
* If the inode is mounted on, perform
* the indicated indirection.
* In all cases, a pointer to a locked
* inode structure is returned.
*
* panic: no imt -- if the mounted file
* system is not in the mount table.
* "cannot happen"
*/
struct inode *
iget(dev, fs, ino)
dev_t dev;
register struct fs *fs;
ino_t ino;
{
register struct inode *ip;
register union ihead *ih;
register struct mount *mp;
register struct buf *bp;
register struct dinode *dp;
register struct inode *iq;
loop:
if (getfs(dev) != fs)
panic("iget: bad fs");
ih = &ihead[INOHASH(dev, ino)];
for (ip = ih->ih_chain[0]; ip != (struct inode *)ih; ip = ip->i_forw)
if (ino == ip->i_number && dev == ip->i_dev) {
if ((ip->i_flag&ILOCK) != 0) {
ip->i_flag |= IWANT;
sleep((caddr_t)ip, PINOD);
goto loop;
}
if ((ip->i_flag&IMOUNT) != 0) {
for (mp = &mount[0]; mp < &mount[NMOUNT]; mp++)
if(mp->m_inodp == ip) {
dev = mp->m_dev;
fs = mp->m_bufp->b_un.b_fs;
ino = ROOTINO;
goto loop;
}
panic("no imt");
}
if (ip->i_count == 0) { /* ino on free list */
if (iq = ip->i_freef)
iq->i_freeb = ip->i_freeb;
else
ifreet = ip->i_freeb;
*ip->i_freeb = iq;
ip->i_freef = NULL;
ip->i_freeb = NULL;
}
ip->i_count++;
ip->i_flag |= ILOCK;
return(ip);
}
if ((ip = ifreeh) == NULL) {
tablefull("inode");
u.u_error = ENFILE;
return(NULL);
}
if (iq = ip->i_freef)
iq->i_freeb = &ifreeh;
ifreeh = iq;
ip->i_freef = NULL;
ip->i_freeb = NULL;
/*
* Now to take inode off the hash chain it was on
* (initially, or after an iflush, it is on a "hash chain"
* consisting entirely of itself, and pointed to by no-one,
* but that doesn't matter), and put it on the chain for
* its new (ino, dev) pair
*/
remque(ip);
insque(ip, ih);
#ifdef QUOTA
dqrele(ip->i_dquot);
#endif
ip->i_dev = dev;
ip->i_fs = fs;
ip->i_number = ino;
ip->i_flag = ILOCK;
ip->i_count++;
ip->i_lastr = 0;
bp = bread(dev, fsbtodb(fs, itod(fs, ino)), fs->fs_bsize);
/*
* Check I/O errors
*/
if ((bp->b_flags&B_ERROR) != 0) {
brelse(bp);
/*
* the inode doesn't contain anything useful, so it would
* be misleading to leave it on its hash chain.
* 'iput' will take care of putting it back on the free list.
*/
remque(ip);
ip->i_forw = ip;
ip->i_back = ip;
/*
* we also loose its inumber, just in case (as iput
* doesn't do that any more) - but as it isn't on its
* hash chain, I doubt if this is really necessary .. kre
* (probably the two methods are interchangable)
*/
ip->i_number = 0;
#ifdef QUOTA
ip->i_dquot = NODQUOT;
#endif
iput(ip);
return(NULL);
}
dp = bp->b_un.b_dino;
dp += itoo(fs, ino);
ip->i_ic = dp->di_ic;
brelse(bp);
#ifdef QUOTA
if (ip->i_mode == 0)
ip->i_dquot = NODQUOT;
else
ip->i_dquot = inoquota(ip);
#endif
return (ip);
}
/*
* Decrement reference count of
* an inode structure.
* On the last reference,
* write the inode out and if necessary,
* truncate and deallocate the file.
*/
iput(ip)
register struct inode *ip;
{
if ((ip->i_flag & ILOCK) == 0)
panic("iput");
iunlock(ip);
irele(ip);
}
irele(ip)
register struct inode *ip;
{
register int i, x;
register struct inode *jp;
int mode;
if (ip->i_count == 1) {
ip->i_flag |= ILOCK;
if (ip->i_nlink <= 0) {
itrunc(ip, 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
chkiq(ip->i_dev, ip, ip->i_uid, 0);
dqrele(ip->i_dquot);
ip->i_dquot = NODQUOT;
#endif
}
IUPDAT(ip, &time, &time, 0);
iunlock(ip);
ip->i_flag = 0;
/*
* Put the inode on the end of the free list.
* Possibly in some cases it would be better to
* put the inode at the head of the free list,
* (eg: where i_mode == 0 || i_number == 0)
* but I will think about that later .. kre
* (i_number is rarely 0 - only after an i/o error in iget,
* where i_mode == 0, the inode will probably be wanted
* again soon for an ialloc, so possibly we should keep it)
*/
if (ifreeh) {
*ifreet = ip;
ip->i_freeb = ifreet;
} else {
ifreeh = ip;
ip->i_freeb = &ifreeh;
}
ip->i_freef = NULL;
ifreet = &ip->i_freef;
}
ip->i_count--;
}
/*
* 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 insure
* i/o order so wait for write to complete.
*/
iupdat(ip, ta, tm, waitfor)
register struct inode *ip;
time_t *ta, *tm;
int waitfor;
{
register struct buf *bp;
struct dinode *dp;
register struct fs *fp;
fp = ip->i_fs;
if ((ip->i_flag & (IUPD|IACC|ICHG)) != 0) {
if (fp->fs_ronly)
return;
bp = bread(ip->i_dev, fsbtodb(fp, itod(fp, ip->i_number)),
fp->fs_bsize);
if (bp->b_flags & B_ERROR) {
brelse(bp);
return;
}
if (ip->i_flag&IACC)
ip->i_atime = *ta;
if (ip->i_flag&IUPD)
ip->i_mtime = *tm;
if (ip->i_flag&ICHG)
ip->i_ctime = time;
ip->i_flag &= ~(IUPD|IACC|ICHG);
dp = bp->b_un.b_dino + itoo(fp, ip->i_number);
dp->di_ic = ip->i_ic;
if (waitfor)
bwrite(bp);
else
bdwrite(bp);
}
}
/*
* Truncate the inode ip to at most
* length size. Free affected disk
* blocks -- the blocks of the file
* are removed in reverse order.
*/
itrunc(ip, length)
register struct inode *ip;
register int length;
{
register i;
dev_t dev;
daddr_t bn;
struct inode itmp;
register struct fs *fs;
#ifdef QUOTA
register long cnt = 0;
long tloop();
#endif
/*
* Only plain files, directories and symbolic
* links contain blocks.
*/
i = ip->i_mode & IFMT;
if (i != IFREG && i != IFDIR && i != IFLNK)
return;
if (ip->i_size <= length)
return;
/*
* Clean inode on disk before freeing blocks
* to insure no duplicates if system crashes.
*/
itmp = *ip;
itmp.i_size = length;
for (i = 0; i < NDADDR; i++)
itmp.i_db[i] = 0;
for (i = 0; i < NIADDR; i++)
itmp.i_ib[i] = 0;
itmp.i_flag |= ICHG|IUPD;
iupdat(&itmp, &time, &time, 1);
ip->i_flag &= ~(IUPD|IACC|ICHG);
/*
* Now return blocks to free list... if machine
* crashes, they will be harmless MISSING blocks.
*/
dev = ip->i_dev;
fs = ip->i_fs;
/*
* release double indirect block first
*/
bn = ip->i_ib[NIADDR-1];
if (bn != (daddr_t)0) {
ip->i_ib[NIADDR - 1] = (daddr_t)0;
#ifdef QUOTA
cnt +=
#endif
tloop(ip, bn, 1);
}
/*
* release single indirect blocks second
*/
for (i = NIADDR - 2; i >= 0; i--) {
bn = ip->i_ib[i];
if (bn != (daddr_t)0) {
ip->i_ib[i] = (daddr_t)0;
#ifdef QUOTA
cnt +=
#endif
tloop(ip, bn, 0);
}
}
/*
* finally release direct blocks
*/
for (i = NDADDR - 1; i>=0; i--) {
register size;
bn = ip->i_db[i];
if (bn == (daddr_t)0)
continue;
ip->i_db[i] = (daddr_t)0;
fre(ip, bn, size = (off_t)blksize(fs, ip, i));
#ifdef QUOTA
cnt += size / DEV_BSIZE;
#endif
}
ip->i_size = 0;
/*
* Inode was written and flags updated above.
* No need to modify flags here.
*/
#ifdef QUOTA
(void) chkdq(ip, -cnt, 0);
#endif
}
#ifdef QUOTA
long
#endif
tloop(ip, bn, indflg)
register struct inode *ip;
daddr_t bn;
int indflg;
{
register i;
register struct buf *bp;
register daddr_t *bap;
register struct fs *fs;
daddr_t nb;
#ifdef QUOTA
register long cnt = 0;
#endif
bp = NULL;
fs = ip->i_fs;
for (i = NINDIR(fs) - 1; i >= 0; i--) {
if (bp == NULL) {
bp = bread(ip->i_dev, fsbtodb(fs, bn), fs->fs_bsize);
if (bp->b_flags & B_ERROR) {
brelse(bp);
return;
}
bap = bp->b_un.b_daddr;
}
nb = bap[i];
if (nb == (daddr_t)0)
continue;
if (indflg) {
#ifdef QUOTA
cnt +=
#endif
tloop(ip, nb, 0);
} else {
fre(ip, nb, fs->fs_bsize);
#ifdef QUOTA
cnt += fs->fs_bsize / DEV_BSIZE;
#endif
}
}
if (bp != NULL)
brelse(bp);
fre(ip, bn, fs->fs_bsize);
#ifdef QUOTA
cnt += fs->fs_bsize / DEV_BSIZE;
return(cnt);
#endif
}
/*
* remove any inodes in the inode cache belonging to dev
*
* There should not be any active ones, return error if any are found
* (nb: this is a user error, not a system err)
*
* Also, count the references to dev by block devices - this really
* has nothing to do with the object of the procedure, but as we have
* to scan the inode table here anyway, we might as well get the
* extra benefit.
*
* this is called from sumount()/sys3.c when dev is being unmounted
*/
#ifdef QUOTA
iflush(dev, iq)
dev_t dev;
struct inode *iq;
#else
iflush(dev)
dev_t dev;
#endif
{
register struct inode *ip;
register open = 0;
for (ip = inode; ip < inodeNINODE; ip++) {
#ifdef QUOTA
if (ip != iq && ip->i_dev == dev)
#else
if (ip->i_dev == dev)
#endif
if (ip->i_count)
return(-1);
else {
remque(ip);
ip->i_forw = ip;
ip->i_back = ip;
/*
* as i_count == 0, the inode was on the free
* list already, just leave it there, it will
* fall off the bottom eventually. We could
* perhaps move it to the head of the free
* list, but as umounts are done so
* infrequently, we would gain very little,
* while making the code bigger.
*/
#ifdef QUOTA
dqrele(ip->i_dquot);
ip->i_dquot = NODQUOT;
#endif
}
else if (ip->i_count && (ip->i_mode&IFMT)==IFBLK &&
ip->i_rdev == dev)
open++;
}
return (open);
}
#ifdef ilock
#undef ilock
#endif
#ifdef iunlock
#undef iunlock
#endif
/*
* Lock an inode. If its already locked, set the WANT bit and sleep.
*/
ilock(ip)
register struct inode *ip;
{
while (ip->i_flag&ILOCK) {
ip->i_flag |= IWANT;
sleep((caddr_t)ip, PINOD);
}
ip->i_flag |= ILOCK;
}
/*
* Unlock an inode. If WANT bit is on, wakeup.
*/
iunlock(ip)
register struct inode *ip;
{
ip->i_flag &= ~ILOCK;
if (ip->i_flag&IWANT) {
ip->i_flag &= ~IWANT;
wakeup((caddr_t)ip);
}
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.