patch-2.4.0-test9 linux/fs/minix/truncate.c

• Lines: 421
• Date: Wed Dec 31 16:00:00 1969
• Orig file: v2.4.0-test8/linux/fs/minix/truncate.c
• Orig date: Tue Sep 5 14:07:30 2000

diff -u --recursive --new-file v2.4.0-test8/linux/fs/minix/truncate.c linux/fs/minix/truncate.c
@@ -1,420 +0,0 @@
-/*
- *  linux/fs/truncate.c
- *
- *  Copyright (C) 1991, 1992  Linus Torvalds
- *
- *  Copyright (C) 1996  Gertjan van Wingerde (gertjan@cs.vu.nl)
- *	Minix V2 fs support.
- */
-
-#include <linux/errno.h>
-#include <linux/sched.h>
-#include <linux/minix_fs.h>
-#include <linux/stat.h>
-#include <linux/fcntl.h>
-
-#define DIRECT_BLOCK		((inode->i_size + 1023) >> 10)
-#define INDIRECT_BLOCK(offset)	(DIRECT_BLOCK-offset)
-#define V1_DINDIRECT_BLOCK(offset) ((DIRECT_BLOCK-offset)>>9)
-#define V2_DINDIRECT_BLOCK(offset) ((DIRECT_BLOCK-offset)>>8)
-#define TINDIRECT_BLOCK(offset) ((DIRECT_BLOCK-(offset))>>8)
-
-/*
- * 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.
- */
-
-#define DATA_BUFFER_USED(bh) \
-	(atomic_read(&bh->b_count) > 1 || buffer_locked(bh))
-
-/*
- * The functions for minix V1 fs truncation.
- */
-static int V1_trunc_direct(struct inode * inode)
-{
-	unsigned short * p;
-	struct buffer_head * bh;
-	int i, tmp;
-	int retry = 0;
-
-repeat:
-	for (i = DIRECT_BLOCK ; i < 7 ; i++) {
-		p = i + inode->u.minix_i.u.i1_data;
-		if (!(tmp = *p))
-			continue;
-		bh = get_hash_table(inode->i_dev,tmp,BLOCK_SIZE);
-		if (i < DIRECT_BLOCK) {
-			brelse(bh);
-			goto repeat;
-		}
-		if ((bh && DATA_BUFFER_USED(bh)) || tmp != *p) {
-			retry = 1;
-			brelse(bh);
-			continue;
-		}
-		*p = 0;
-		mark_inode_dirty(inode);
-		bforget(bh);
-		minix_free_block(inode,tmp);
-	}
-	return retry;
-}
-
-static int V1_trunc_indirect(struct inode * inode, int offset, unsigned short * p)
-{
-	struct buffer_head * bh;
-	int i, tmp;
-	struct buffer_head * ind_bh;
-	unsigned short * ind;
-	int retry = 0;
-
-	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(offset) ; i < 512 ; i++) {
-		if (i < 0)
-			i = 0;
-		if (i < INDIRECT_BLOCK(offset))
-			goto repeat;
-		ind = i+(unsigned short *) ind_bh->b_data;
-		tmp = *ind;
-		if (!tmp)
-			continue;
-		bh = get_hash_table(inode->i_dev,tmp,BLOCK_SIZE);
-		if (i < INDIRECT_BLOCK(offset)) {
-			brelse(bh);
-			goto repeat;
-		}
-		if ((bh && DATA_BUFFER_USED(bh)) || tmp != *ind) {
-			retry = 1;
-			brelse(bh);
-			continue;
-		}
-		*ind = 0;
-		mark_buffer_dirty(ind_bh);
-		bforget(bh);
-		minix_free_block(inode,tmp);
-	}
-	ind = (unsigned short *) ind_bh->b_data;
-	for (i = 0; i < 512; i++)
-		if (*(ind++))
-			break;
-	if (i >= 512) {
-		if (atomic_read(&ind_bh->b_count) != 1)
-			retry = 1;
-		else {
-			tmp = *p;
-			*p = 0;
-			minix_free_block(inode,tmp);
-		}
-	}
-	brelse(ind_bh);
-	return retry;
-}
-
-static int V1_trunc_dindirect(struct inode * inode, int offset, unsigned short *p)
-{
-	int i, tmp;
-	struct buffer_head * dind_bh;
-	unsigned short * dind;
-	int retry = 0;
-
-	if (!(tmp = *p))
-		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 = V1_DINDIRECT_BLOCK(offset) ; i < 512 ; i ++) {
-		if (i < 0)
-			i = 0;
-		if (i < V1_DINDIRECT_BLOCK(offset))
-			goto repeat;
-		dind = i+(unsigned short *) dind_bh->b_data;
-		retry |= V1_trunc_indirect(inode,offset+(i<<9),dind);
-		mark_buffer_dirty(dind_bh);
-	}
-	dind = (unsigned short *) dind_bh->b_data;
-	for (i = 0; i < 512; i++)
-		if (*(dind++))
-			break;
-	if (i >= 512) {
-		if (atomic_read(&dind_bh->b_count) != 1)
-			retry = 1;
-		else {
-			tmp = *p;
-			*p = 0;
-			mark_inode_dirty(inode);
-			minix_free_block(inode,tmp);
-		}
-	}
-	brelse(dind_bh);
-	return retry;
-}
-
-static void V1_minix_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 = V1_trunc_direct(inode);
-		retry |= V1_trunc_indirect(inode, 7, inode->u.minix_i.u.i1_data + 7);
-		retry |= V1_trunc_dindirect(inode, 7+512, inode->u.minix_i.u.i1_data + 8);
-		if (!retry)
-			break;
-		current->counter = 0;
-		schedule();
-	}
-	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
-	mark_inode_dirty(inode);
-}
-
-/*
- * The functions for minix V2 fs truncation.
- */
-static int V2_trunc_direct(struct inode * inode)
-{
-	unsigned long * p;
-	struct buffer_head * bh;
-	int i, tmp;
-	int retry = 0;
-
-repeat:
-	for (i = DIRECT_BLOCK ; i < 7 ; i++) {
-		p = (unsigned long *) inode->u.minix_i.u.i2_data + i;
-		if (!(tmp = *p))
-			continue;
-		bh = get_hash_table(inode->i_dev,tmp,BLOCK_SIZE);
-		if (i < DIRECT_BLOCK) {
-			brelse(bh);
-			goto repeat;
-		}
-		if ((bh && DATA_BUFFER_USED(bh)) || tmp != *p) {
-			retry = 1;
-			brelse(bh);
-			continue;
-		}
-		*p = 0;
-		mark_inode_dirty(inode);
-		bforget(bh);
-		minix_free_block(inode,tmp);
-	}
-	return retry;
-}
-
-static int V2_trunc_indirect(struct inode * inode, int offset, unsigned long * p)
-{
-	struct buffer_head * bh;
-	int i, tmp;
-	struct buffer_head * ind_bh;
-	unsigned long * ind;
-	int retry = 0;
-
-	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(offset) ; i < 256 ; i++) {
-		if (i < 0)
-			i = 0;
-		if (i < INDIRECT_BLOCK(offset))
-			goto repeat;
-		ind = i+(unsigned long *) ind_bh->b_data;
-		tmp = *ind;
-		if (!tmp)
-			continue;
-		bh = get_hash_table(inode->i_dev,tmp,BLOCK_SIZE);
-		if (i < INDIRECT_BLOCK(offset)) {
-			brelse(bh);
-			goto repeat;
-		}
-		if ((bh && DATA_BUFFER_USED(bh)) || tmp != *ind) {
-			retry = 1;
-			brelse(bh);
-			continue;
-		}
-		*ind = 0;
-		mark_buffer_dirty(ind_bh);
-		bforget(bh);
-		minix_free_block(inode,tmp);
-	}
-	ind = (unsigned long *) ind_bh->b_data;
-	for (i = 0; i < 256; i++)
-		if (*(ind++))
-			break;
-	if (i >= 256) {
-		if (atomic_read(&ind_bh->b_count) != 1)
-			retry = 1;
-		else {
-			tmp = *p;
-			*p = 0;
-			minix_free_block(inode,tmp);
-		}
-	}
-	brelse(ind_bh);
-	return retry;
-}
-
-static int V2_trunc_dindirect(struct inode * inode, int offset, unsigned long *p)
-{
-	int i, tmp;
-	struct buffer_head * dind_bh;
-	unsigned long * dind;
-	int retry = 0;
-
-	if (!(tmp = *p))
-		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 = V2_DINDIRECT_BLOCK(offset) ; i < 256 ; i ++) {
-		if (i < 0)
-			i = 0;
-		if (i < V2_DINDIRECT_BLOCK(offset))
-			goto repeat;
-		dind = i+(unsigned long *) dind_bh->b_data;
-		retry |= V2_trunc_indirect(inode,offset+(i<<8),dind);
-		mark_buffer_dirty(dind_bh);
-	}
-	dind = (unsigned long *) dind_bh->b_data;
-	for (i = 0; i < 256; i++)
-		if (*(dind++))
-			break;
-	if (i >= 256) {
-		if (atomic_read(&dind_bh->b_count) != 1)
-			retry = 1;
-		else {
-			tmp = *p;
-			*p = 0;
-			mark_inode_dirty(inode);
-			minix_free_block(inode,tmp);
-		}
-	}
-	brelse(dind_bh);
-	return retry;
-}
-
-static int V2_trunc_tindirect(struct inode * inode, int offset, unsigned long * p)
-{
-        int i, tmp;
-        struct buffer_head * tind_bh;
-        unsigned long * tind;
-        int retry = 0;
-
-        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(offset) ; i < 256 ; i ++) {
-                if (i < 0)
-                        i = 0;
-                if (i < TINDIRECT_BLOCK(offset))
-                        goto repeat;
-                tind = i+(unsigned long *) tind_bh->b_data;
-                retry |= V2_trunc_dindirect(inode,offset+(i<<8),tind);
-                mark_buffer_dirty(tind_bh);
-	}
-        tind = (unsigned long *) tind_bh->b_data;
-        for (i = 0; i < 256; i++)
-                if (*(tind++))
-                        break;
-        if (i >= 256) {
-                if (atomic_read(&tind_bh->b_count) != 1)
-                        retry = 1;
-                else {
-                        tmp = *p;
-                        *p = 0;
-                        mark_inode_dirty(inode);
-                        minix_free_block(inode,tmp);
-		}
-	}
-        brelse(tind_bh);
-        return retry;
-}
-
-static void V2_minix_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 = V2_trunc_direct(inode);
-		retry |= V2_trunc_indirect(inode,7,
-			(unsigned long *) inode->u.minix_i.u.i2_data + 7);
-		retry |= V2_trunc_dindirect(inode, 7+256, 
-			(unsigned long *) inode->u.minix_i.u.i2_data + 8);
-		retry |= V2_trunc_tindirect(inode, 7+256+256*256, 
-			(unsigned long *) inode->u.minix_i.u.i2_data + 9);
-		if (!retry)
-			break;
-		run_task_queue(&tq_disk);
-		current->policy |= SCHED_YIELD;
-		schedule();
-	}
-	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
-	mark_inode_dirty(inode);
-}
-
-/*
- * The function that is called for file truncation.
- */
-void minix_truncate(struct inode * inode)
-{
-	if (INODE_VERSION(inode) == MINIX_V1)
-		V1_minix_truncate(inode);
-	else
-		V2_minix_truncate(inode);
-}