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

• Lines: 198
• Date: Thu Jan 1 02:00:00 1970
• Orig file: v2.1.20/linux/fs/xiafs/truncate.c
• Orig date: Wed Nov 8 12:30:22 1995

diff -u --recursive --new-file v2.1.20/linux/fs/xiafs/truncate.c linux/fs/xiafs/truncate.c
@@ -1,197 +0,0 @@
-/*
- *  linux/fs/xiafs/truncate.c
- *
- *  Copyright (C) Q. Frank Xia, 1993.
- *  
- *  Based on Linus' minix/truncate.c
- *  Copyright (C) Linus Torvalds, 1991, 1992.
- *
- *  This software may be redistributed per Linux Copyright.
- */
-
-#include <linux/errno.h>
-#include <linux/sched.h>
-#include <linux/xia_fs.h>
-#include <linux/stat.h>
-#include <linux/fcntl.h>
-
-#include "xiafs_mac.h"
-
-/*
- * Linus' comment:
- *
- * 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 DT_ZONE		((inode->i_size + XIAFS_ZSIZE(inode->i_sb) - 1) \
-			 >> XIAFS_ZSIZE_BITS(inode->i_sb) )
-
-static int trunc_direct(struct inode * inode)
-{
-    u_long * lp;
-    struct buffer_head * bh;
-    int i, tmp;
-    int retry = 0;
-
-repeat:
-    for (i = DT_ZONE ; i < 8 ; i++) {
-        if (i < DT_ZONE)
-	    goto repeat;
-        lp=i + inode->u.xiafs_i.i_zone;
-        if (!(tmp = *lp))
-	    continue;
-	bh = getblk(inode->i_dev, tmp, XIAFS_ZSIZE(inode->i_sb));
-	if (i < DT_ZONE) {
-	    brelse(bh);
-	    goto repeat;
-	}
-	if ((bh && bh->b_count != 1) || tmp != *lp)
-	    retry = 1;
-	else {
-	    *lp = 0;
-	    inode->i_dirt = 1;
-	    inode->i_blocks-=2 << XIAFS_ZSHIFT(inode->i_sb);
-	    xiafs_free_zone(inode->i_sb, tmp);
-	}
-	brelse(bh);
-    }
-    return retry;
-}
-
-static int trunc_indirect(struct inode * inode, int addr_off, u_long * lp)
-{
-
-#define INDT_ZONE 	(DT_ZONE - addr_off)
-
-    struct buffer_head * bh, * ind_bh;
-    int i, tmp;
-    u_long * indp;
-    int retry = 0;
-
-    if ( !(tmp=*lp) )
-        return 0;
-    ind_bh = bread(inode->i_dev, tmp, XIAFS_ZSIZE(inode->i_sb));
-    if (tmp != *lp) {
-        brelse(ind_bh);
-	return 1;
-    }
-    if (!ind_bh) {
-        *lp = 0;
-	return 0;
-    }
-repeat:
-    for (i = INDT_ZONE<0?0:INDT_ZONE; i < XIAFS_ADDRS_PER_Z(inode->i_sb); i++) {
-        if (i < INDT_ZONE)
-	    goto repeat;
-        indp = i+(u_long *) ind_bh->b_data;
-	if (!(tmp=*indp))
-	    continue;
-	bh = getblk(inode->i_dev, tmp, XIAFS_ZSIZE(inode->i_sb));
-	if (i < INDT_ZONE) {
-	    brelse(bh);
-	    goto repeat;
-	}
-	if ((bh && bh->b_count != 1) || tmp != *indp)
-	    retry = 1;
-	else {
-	    *indp = 0;
-	    mark_buffer_dirty(ind_bh, 1);
-	    inode->i_blocks-= 2 << XIAFS_ZSHIFT(inode->i_sb);
-	    xiafs_free_zone(inode->i_sb, tmp);
-	}
-	brelse(bh);
-    }
-    indp = (u_long *) ind_bh->b_data;
-    for (i = 0; i < XIAFS_ADDRS_PER_Z(inode->i_sb) && !(*indp++); i++) ;
-    if (i >= XIAFS_ADDRS_PER_Z(inode->i_sb)) {
-      if (ind_bh->b_count != 1)
-	   retry = 1;
-      else {
-	  tmp = *lp;
-	  *lp = 0;
-	  inode->i_blocks-= 2 << XIAFS_ZSHIFT(inode->i_sb);
-	  xiafs_free_zone(inode->i_sb, tmp);
-      }
-    }
-    brelse(ind_bh);
-    return retry;
-}
-		
-static int trunc_dindirect(struct inode * inode)
-{
-
-#define DINDT_ZONE \
-    ((DT_ZONE-XIAFS_ADDRS_PER_Z(inode->i_sb)-8)>>XIAFS_ADDRS_PER_Z_BITS(inode->i_sb))
-
-    int i, tmp;
-    struct buffer_head * dind_bh;
-    u_long * dindp, * lp;
-    int retry = 0;
-
-    lp = &(inode->u.xiafs_i.i_dind_zone);
-    if (!(tmp = *lp))
-        return 0;
-    dind_bh = bread(inode->i_dev, tmp, XIAFS_ZSIZE(inode->i_sb));
-    if (tmp != *lp) {
-        brelse(dind_bh);
-	return 1;
-    }
-    if (!dind_bh) {
-        *lp = 0;
-	return 0;
-    }
-repeat:
-    for (i=DINDT_ZONE<0?0:DINDT_ZONE ; i < XIAFS_ADDRS_PER_Z(inode->i_sb) ; i ++) {
-        if (i < DINDT_ZONE)
-	    goto repeat;
-        dindp = i+(u_long *) dind_bh->b_data;
-	retry |= trunc_indirect(inode, 
-				8+((1+i)<<XIAFS_ADDRS_PER_Z_BITS(inode->i_sb)), 
-				dindp);
-	mark_buffer_dirty(dind_bh, 1);
-    }
-    dindp = (u_long *) dind_bh->b_data;
-    for (i = 0; i < XIAFS_ADDRS_PER_Z(inode->i_sb) && !(*dindp++); i++);
-    if (i >= XIAFS_ADDRS_PER_Z(inode->i_sb)) {
-        if (dind_bh->b_count != 1)
-	    retry = 1;
-	else {
-	    tmp = *lp;
-	    *lp = 0;
-	    inode->i_dirt = 1;
-	    inode->i_blocks-=2 << XIAFS_ZSHIFT(inode->i_sb);
-	    xiafs_free_zone(inode->i_sb, tmp);
-	}
-    }
-    brelse(dind_bh);
-    return retry;
-}
-
-void xiafs_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, 8, &(inode->u.xiafs_i.i_ind_zone)); 
-        retry |= trunc_dindirect(inode);
-	if (!retry)
-	    break;
-	current->counter = 0;
-	schedule();
-    }
-    inode->i_ctime = inode->i_mtime = CURRENT_TIME;
-    inode->i_dirt = 1;
-}