patch-2.1.21 linux/fs/ext/truncate.c

• Lines: 253
• Date: Thu Jan 1 02:00:00 1970
• Orig file: v2.1.20/linux/fs/ext/truncate.c
• Orig date: Wed Oct 9 08:55:22 1996

diff -u --recursive --new-file v2.1.20/linux/fs/ext/truncate.c linux/fs/ext/truncate.c
@@ -1,252 +0,0 @@
-/*
- *  linux/fs/ext/truncate.c
- *
- *  Copyright (C) 1992  Remy Card (card@masi.ibp.fr)
- *
- *  from
- *
- *  linux/fs/minix/truncate.c
- *
- *  Copyright (C) 1991, 1992  Linus Torvalds
- */
-
-#include <linux/sched.h>
-#include <linux/ext_fs.h>
-#include <linux/stat.h>
-#include <linux/fcntl.h>
-#include <linux/errno.h>
-
-/*
- * Truncate has the most races in the whole filesystem: coding it is
- * a pain in the a**. Especially as I don't do any locking...
- *
- * The code may look a bit weird, but that's just because I've tried to
- * handle things like file-size changes in a somewhat graceful manner.
- * Anyway, truncating a file at the same time somebody else writes to it
- * is likely to result in pretty weird behaviour...
- *
- * The new code handles normal truncates (size = 0) as well as the more
- * general case (size = XXX). I hope.
- */
-
-static int trunc_direct(struct inode * inode)
-{
-	int i, tmp;
-	unsigned long * p;
-	struct buffer_head * bh;
-	int retry = 0;
-#define DIRECT_BLOCK ((inode->i_size + 1023) >> 10)
-
-repeat:
-	for (i = DIRECT_BLOCK ; i < 9 ; i++) {
-		p = inode->u.ext_i.i_data+i;
-		if (!(tmp = *p))
-			continue;
-		bh = getblk(inode->i_dev,tmp,BLOCK_SIZE);
-		if (i < DIRECT_BLOCK) {
-			brelse(bh);
-			goto repeat;
-		}
-		if ((bh && bh->b_count != 1) || tmp != *p) {
-			retry = 1;
-			brelse(bh);
-			continue;
-		}
-		*p = 0;
-		inode->i_dirt = 1;
-		brelse(bh);
-		ext_free_block(inode->i_sb,tmp);
-	}
-	return retry;
-}
-
-static int trunc_indirect(struct inode * inode, int offset, unsigned long * p)
-{
-	int i, tmp;
-	struct buffer_head * bh;
-	struct buffer_head * ind_bh;
-	unsigned long * ind;
-	int retry = 0;
-#define INDIRECT_BLOCK (DIRECT_BLOCK-offset)
-
-	tmp = *p;
-	if (!tmp)
-		return 0;
-	ind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);
-	if (tmp != *p) {
-		brelse(ind_bh);
-		return 1;
-	}
-	if (!ind_bh) {
-		*p = 0;
-		return 0;
-	}
-repeat:
-	for (i = INDIRECT_BLOCK ; i < 256 ; i++) {
-		if (i < 0)
-			i = 0;
-		if (i < INDIRECT_BLOCK)
-			goto repeat;
-		ind = i+(unsigned long *) ind_bh->b_data;
-		tmp = *ind;
-		if (!tmp)
-			continue;
-		bh = getblk(inode->i_dev,tmp,BLOCK_SIZE);
-		if (i < INDIRECT_BLOCK) {
-			brelse(bh);
-			goto repeat;
-		}
-		if ((bh && bh->b_count != 1) || tmp != *ind) {
-			retry = 1;
-			brelse(bh);
-			continue;
-		}
-		*ind = 0;
-		mark_buffer_dirty(ind_bh, 1);
-		brelse(bh);
-		ext_free_block(inode->i_sb,tmp);
-	}
-	ind = (unsigned long *) ind_bh->b_data;
-	for (i = 0; i < 256; i++)
-		if (*(ind++))
-			break;
-	if (i >= 256)
-		if (ind_bh->b_count != 1)
-			retry = 1;
-		else {
-			tmp = *p;
-			*p = 0;
-			inode->i_dirt = 1;
-			ext_free_block(inode->i_sb,tmp);
-		}
-	brelse(ind_bh);
-	return retry;
-}
-
-static int trunc_dindirect(struct inode * inode, int offset, unsigned long * p)
-{
-	int i,tmp;
-	struct buffer_head * dind_bh;
-	unsigned long * dind;
-	int retry = 0;
-#define DINDIRECT_BLOCK ((DIRECT_BLOCK-offset)>>8)
-
-	tmp = *p;
-	if (!tmp)
-		return 0;
-	dind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);
-	if (tmp != *p) {
-		brelse(dind_bh);
-		return 1;
-	}
-	if (!dind_bh) {
-		*p = 0;
-		return 0;
-	}
-repeat:
-	for (i = DINDIRECT_BLOCK ; i < 256 ; i ++) {
-		if (i < 0)
-			i = 0;
-		if (i < DINDIRECT_BLOCK)
-			goto repeat;
-		dind = i+(unsigned long *) dind_bh->b_data;
-		tmp = *dind;
-		if (!tmp)
-			continue;
-		retry |= trunc_indirect(inode,offset+(i<<8),dind);
-		mark_buffer_dirty(dind_bh, 1);
-	}
-	dind = (unsigned long *) dind_bh->b_data;
-	for (i = 0; i < 256; i++)
-		if (*(dind++))
-			break;
-	if (i >= 256)
-		if (dind_bh->b_count != 1)
-			retry = 1;
-		else {
-			tmp = *p;
-			*p = 0;
-			inode->i_dirt = 1;
-			ext_free_block(inode->i_sb,tmp);
-		}
-	brelse(dind_bh);
-	return retry;
-}
-
-static int trunc_tindirect(struct inode * inode)
-{
-	int i,tmp;
-	struct buffer_head * tind_bh;
-	unsigned long * tind, * p;
-	int retry = 0;
-#define TINDIRECT_BLOCK ((DIRECT_BLOCK-(256*256+256+9))>>16)
-
-	p = inode->u.ext_i.i_data+11;
-	if (!(tmp = *p))
-		return 0;
-	tind_bh = bread(inode->i_dev, tmp, BLOCK_SIZE);
-	if (tmp != *p) {
-		brelse(tind_bh);
-		return 1;
-	}
-	if (!tind_bh) {
-		*p = 0;
-		return 0;
-	}
-repeat:
-	for (i = TINDIRECT_BLOCK ; i < 256 ; i ++) {
-		if (i < 0)
-			i = 0;
-		if (i < TINDIRECT_BLOCK)
-			goto repeat;
-		tind = i+(unsigned long *) tind_bh->b_data;
-		retry |= trunc_dindirect(inode,9+256+256*256+(i<<16),tind);
-		mark_buffer_dirty(tind_bh, 1);
-	}
-	tind = (unsigned long *) tind_bh->b_data;
-	for (i = 0; i < 256; i++)
-		if (*(tind++))
-			break;
-	if (i >= 256)
-		if (tind_bh->b_count != 1)
-			retry = 1;
-		else {
-			tmp = *p;
-			*p = 0;
-			inode->i_dirt = 1;
-			ext_free_block(inode->i_sb,tmp);
-		}
-	brelse(tind_bh);
-	return retry;
-}
-
-void ext_truncate(struct inode * inode)
-{
-	int retry;
-
-	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
-	     S_ISLNK(inode->i_mode)))
-		return;
-	while (1) {
-		retry = trunc_direct(inode);
-		retry |= trunc_indirect(inode,9,inode->u.ext_i.i_data+9);
-		retry |= trunc_dindirect(inode,9+256,inode->u.ext_i.i_data+10);
-		retry |= trunc_tindirect(inode);
-		if (!retry)
-			break;
-		current->counter = 0;
-		schedule();
-	}
-	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
-	inode->i_dirt = 1;
-}
-
-/*
- * Called when an inode is released. Note that this is different
- * from ext_open: open gets called at every open, but release
- * gets called only when /all/ the files are closed.
- */
-void ext_release(struct inode * inode, struct file * filp)
-{
-	printk("ext_release not implemented\n");
-}