patch-2.1.112 linux/fs/ufs/truncate.c

• Lines: 474
• Date: Sun Jul 26 23:30:27 1998
• Orig file: v2.1.111/linux/fs/ufs/truncate.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.111/linux/fs/ufs/truncate.c linux/fs/ufs/truncate.c
@@ -0,0 +1,473 @@
+/*
+ *  linux/fs/ufs/truncate.c
+ *
+ * Copyright (C) 1998
+ * Daniel Pirkl <daniel.pirkl@email.cz>
+ * Charles Uiversity, Faculty of Mathematics and Physics
+ *
+ *  from
+ *
+ *  linux/fs/ext2/truncate.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/truncate.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+/*
+ * Real random numbers for secure rm added 94/02/18
+ * Idea from Pierre del Perugia <delperug@gla.ecoledoc.ibp.fr>
+ */
+
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/ufs_fs.h>
+#include <linux/fcntl.h>
+#include <linux/sched.h>
+#include <linux/stat.h>
+#include <linux/locks.h>
+#include <linux/string.h>
+
+#include "swab.h"
+#include "util.h"
+
+#undef UFS_TRUNCATE_DEBUG
+
+#ifdef UFS_TRUNCATE_DEBUG
+#define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x;
+#else
+#define UFSD(x)
+#endif
+ 
+/*
+ * Secure deletion currently doesn't work. It interacts very badly
+ * with buffers shared with memory mappings, and for that reason
+ * can't be done in the truncate() routines. It should instead be
+ * done separately in "release()" before calling the truncate routines
+ * that will release the actual file blocks.
+ *
+ *		Linus
+ */
+
+#define DIRECT_BLOCK howmany (inode->i_size, uspi->s_bsize)
+#define DIRECT_FRAGMENT howmany (inode->i_size, uspi->s_fsize)
+
+static int ufs_trunc_direct (struct inode * inode)
+{
+	struct super_block * sb;
+	struct ufs_sb_private_info * uspi;
+	struct buffer_head * bh;
+	u32 * p;
+   	unsigned frag1, frag2, frag3, frag4, block1, block2;
+	unsigned frag_to_free, free_count;
+	unsigned i, j, tmp;
+	int retry;
+	unsigned swab;
+	
+	UFSD(("ENTER\n"))
+
+	sb = inode->i_sb;
+	swab = sb->u.ufs_sb.s_swab;
+	uspi = sb->u.ufs_sb.s_uspi;
+	
+	frag_to_free = 0;
+	free_count = 0;
+	retry = 0;
+	
+	frag1 = DIRECT_FRAGMENT;
+	frag4 = min (UFS_NDIR_FRAGMENT, inode->u.ufs_i.i_lastfrag);
+	frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 | uspi->s_fpbmask) + 1) : frag1);
+	frag3 = frag4 & ~uspi->s_fpbmask;
+	block1 = block2 = 0;
+	if (frag2 > frag3) {
+		frag2 = frag4;
+		frag3 = frag4 = 0;
+	}
+	else if (frag2 < frag3) {
+		block1 = ufs_fragstoblks (frag2);
+		block2 = ufs_fragstoblks (frag3);
+	}
+
+	UFSD(("frag1 %u, frag2 %u, block1 %u, block2 %u, frag3 %u, frag4 %u\n", frag1, frag2, block1, block2, frag3, frag4))
+
+	if (frag1 >= frag2)
+		goto next1;		
+
+	/*
+	 * Free first free fragments
+	 */
+	p = inode->u.ufs_i.i_u1.i_data + ufs_fragstoblks (frag1);
+	tmp = SWAB32(*p);
+	if (!tmp )
+		ufs_panic (sb, "ufs_trunc_direct", "internal error");
+	frag1 = ufs_fragnum (frag1);
+	frag2 = ufs_fragnum (frag2);
+	for (j = frag1; j < frag2; j++) {
+		bh = get_hash_table (sb->s_dev, tmp + j, uspi->s_fsize);
+		if ((bh && bh->b_count != 1) || tmp != SWAB32(*p)) {
+			retry = 1;
+			brelse (bh);
+			goto next1;
+		}
+		bforget (bh);
+	}
+	inode->i_blocks -= (frag2-frag1) << uspi->s_nspfshift;
+	mark_inode_dirty(inode);
+	ufs_free_fragments (inode, tmp + frag1, frag2 - frag1);
+	frag_to_free = tmp + frag1;
+
+next1:
+	/*
+	 * Free whole blocks
+	 */
+	for (i = block1 ; i < block2; i++) {
+		p = inode->u.ufs_i.i_u1.i_data + i;
+		tmp = SWAB32(*p);
+		if (!tmp)
+			continue;
+		for (j = 0; j < uspi->s_fpb; j++) {
+			bh = get_hash_table (sb->s_dev, tmp + j, uspi->s_fsize);
+			if ((bh && bh->b_count != 1) || tmp != SWAB32(*p)) {
+				retry = 1;
+				brelse (bh);
+				goto next2;
+			}
+			bforget (bh);
+		}
+		*p = SWAB32(0);
+		inode->i_blocks -= uspi->s_nspb;
+		mark_inode_dirty(inode);
+		if (free_count == 0) {
+			frag_to_free = tmp;
+			free_count = uspi->s_fpb;
+		} else if (free_count > 0 && frag_to_free == tmp - free_count)
+			free_count += uspi->s_fpb;
+		else {
+			ufs_free_blocks (inode, frag_to_free, free_count);
+			frag_to_free = tmp;
+			free_count = uspi->s_fpb;
+		}
+next2:
+	}
+	
+	if (free_count > 0)
+		ufs_free_blocks (inode, frag_to_free, free_count);
+
+	if (frag3 >= frag4)
+		goto next3;
+
+	/*
+	 * Free last free fragments
+	 */
+	p = inode->u.ufs_i.i_u1.i_data + ufs_fragstoblks (frag3);
+	tmp = SWAB32(*p);
+	if (!tmp )
+		ufs_panic(sb, "ufs_truncate_direct", "internal error");
+	frag4 = ufs_fragnum (frag4);
+	for (j = 0; j < frag4; j++) {
+		bh = get_hash_table (sb->s_dev, tmp + j, uspi->s_fsize);
+		if ((bh && bh->b_count != 1) || tmp != SWAB32(*p)) {
+			retry = 1;
+			brelse (bh);
+			goto next1;
+		}
+		bforget (bh);
+	}
+	*p = SWAB32(0);
+	inode->i_blocks -= frag4 << uspi->s_nspfshift;
+	mark_inode_dirty(inode);
+	ufs_free_fragments (inode, tmp, frag4);
+ next3:
+
+	UFSD(("EXIT\n"))
+	return retry;
+}
+
+
+static int ufs_trunc_indirect (struct inode * inode, unsigned offset, u32 * p)
+{
+	struct super_block * sb;
+	struct ufs_sb_private_info * uspi;
+	struct ufs_buffer_head * ind_ubh;
+	struct buffer_head * bh;
+	u32 * ind;
+	unsigned indirect_block, i, j, tmp;
+	unsigned frag_to_free, free_count;
+	int retry;
+	unsigned swab;
+
+	UFSD(("ENTER\n"))
+		
+	sb = inode->i_sb;
+	swab = sb->u.ufs_sb.s_swab;
+	uspi = sb->u.ufs_sb.s_uspi;
+
+	frag_to_free = 0;
+	free_count = 0;
+	retry = 0;
+	
+	tmp = SWAB32(*p);
+	if (!tmp)
+		return 0;
+	ind_ubh = ubh_bread (sb->s_dev, tmp, uspi->s_bsize);
+	if (tmp != SWAB32(*p)) {
+		ubh_brelse (ind_ubh);
+		return 1;
+	}
+	if (!ind_ubh) {
+		*p = SWAB32(0);
+		return 0;
+	}
+
+	indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0;
+	for (i = indirect_block; i < uspi->s_apb; i++) {
+		ind = ubh_get_addr32 (ind_ubh, i);
+		tmp = SWAB32(*ind);
+		if (!tmp)
+			continue;
+		for (j = 0; j < uspi->s_fpb; j++) {
+			bh = get_hash_table (sb->s_dev, tmp + j, uspi->s_fsize);
+			if ((bh && bh->b_count != 1) || tmp != SWAB32(*ind)) {
+				retry = 1;
+				brelse (bh);
+				goto next;
+			}
+			bforget (bh);
+		}	
+		*ind = SWAB32(0);
+		ubh_mark_buffer_dirty(ind_ubh, 1);
+		if (free_count == 0) {
+			frag_to_free = tmp;
+			free_count = uspi->s_fpb;
+		} else if (free_count > 0 && frag_to_free == tmp - free_count)
+			free_count += uspi->s_fpb;
+		else {
+			ufs_free_blocks (inode, frag_to_free, free_count);
+			frag_to_free = tmp;
+			free_count = uspi->s_fpb;
+		}
+		inode->i_blocks -= uspi->s_nspb;
+		mark_inode_dirty(inode);
+next:
+	}
+
+	if (free_count > 0) {
+		ufs_free_blocks (inode, frag_to_free, free_count);
+	}
+	for (i = 0; i < uspi->s_apb; i++)
+		if (SWAB32(*ubh_get_addr32(ind_ubh,i)))
+			break;
+	if (i >= uspi->s_apb) {
+		if (ubh_max_bcount(ind_ubh) != 1) {
+			retry = 1;
+		}
+		else {
+			tmp = SWAB32(*p);
+			*p = SWAB32(0);
+			inode->i_blocks -= uspi->s_nspb;
+			mark_inode_dirty(inode);
+			ufs_free_blocks (inode, tmp, uspi->s_fpb);
+			ubh_bforget(ind_ubh);
+			ind_ubh = NULL;
+		}
+	}
+	if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) {
+		ubh_ll_rw_block (WRITE, 1, &ind_ubh);
+		ubh_wait_on_buffer (ind_ubh);
+	}
+	ubh_brelse (ind_ubh);
+	
+	UFSD(("EXIT\n"))
+	
+	return retry;
+}
+
+static int ufs_trunc_dindirect (struct inode * inode, unsigned offset, u32 * p)
+{
+	struct super_block * sb;
+	struct ufs_sb_private_info * uspi;
+	struct ufs_buffer_head * dind_bh;
+	unsigned i, tmp, dindirect_block;
+	u32 * dind;
+	int retry = 0;
+	unsigned swab;
+	
+	UFSD(("ENTER\n"))
+	
+	sb = inode->i_sb;
+	swab = sb->u.ufs_sb.s_swab;
+	uspi = sb->u.ufs_sb.s_uspi;
+
+	dindirect_block = (DIRECT_BLOCK > offset) 
+		? ((DIRECT_BLOCK - offset) / uspi->s_apb) : 0;
+	retry = 0;
+	
+	tmp = SWAB32(*p);
+	if (!tmp)
+		return 0;
+	dind_bh = ubh_bread (inode->i_dev, tmp, uspi->s_bsize);
+	if (tmp != SWAB32(*p)) {
+		ubh_brelse (dind_bh);
+		return 1;
+	}
+	if (!dind_bh) {
+		*p = SWAB32(0);
+		return 0;
+	}
+
+	for (i = dindirect_block ; i < uspi->s_apb ; i++) {
+		dind = ubh_get_addr32 (dind_bh, i);
+		tmp = SWAB32(*dind);
+		if (!tmp)
+			continue;
+		retry |= ufs_trunc_indirect (inode, offset + (i << uspi->s_apbshift), dind);
+		ubh_mark_buffer_dirty(dind_bh, 1);
+	}
+
+	for (i = 0; i < uspi->s_apb; i++)
+		if (SWAB32(*ubh_get_addr32 (dind_bh, i)))
+			break;
+	if (i >= uspi->s_apb) {
+		if (ubh_max_bcount(dind_bh) != 1)
+			retry = 1;
+		else {
+			tmp = SWAB32(*p);
+			*p = SWAB32(0);
+			inode->i_blocks -= uspi->s_nspb;
+			mark_inode_dirty(inode);
+			ufs_free_blocks (inode, tmp, uspi->s_fpb);
+			ubh_bforget(dind_bh);
+			dind_bh = NULL;
+		}
+	}
+	if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) {
+		ubh_ll_rw_block (WRITE, 1, &dind_bh);
+		ubh_wait_on_buffer (dind_bh);
+	}
+	ubh_brelse (dind_bh);
+	
+	UFSD(("EXIT\n"))
+	
+	return retry;
+}
+
+static int ufs_trunc_tindirect (struct inode * inode)
+{
+	struct super_block * sb;
+	struct ufs_sb_private_info * uspi;
+	struct ufs_buffer_head * tind_bh;
+	unsigned tindirect_block, tmp, i;
+	u32 * tind, * p;
+	int retry;
+	unsigned swab;
+	
+	UFSD(("ENTER\n"))
+
+	sb = inode->i_sb;
+	swab = sb->u.ufs_sb.s_swab;
+	uspi = sb->u.ufs_sb.s_uspi;
+	retry = 0;
+	
+	tindirect_block = (DIRECT_BLOCK > (UFS_NDADDR + uspi->s_apb + uspi->s_2apb))
+		? ((DIRECT_BLOCK - UFS_NDADDR - uspi->s_apb - uspi->s_2apb) / uspi->s_2apb) : 0;
+	p = inode->u.ufs_i.i_u1.i_data + UFS_TIND_BLOCK;
+	if (!(tmp = SWAB32(*p)))
+		return 0;
+	tind_bh = ubh_bread (sb->s_dev, tmp, uspi->s_bsize);
+	if (tmp != SWAB32(*p)) {
+		ubh_brelse (tind_bh);
+		return 1;
+	}
+	if (!tind_bh) {
+		*p = SWAB32(0);
+		return 0;
+	}
+
+	for (i = tindirect_block ; i < uspi->s_apb ; i++) {
+		tind = ubh_get_addr32 (tind_bh, i);
+		retry |= ufs_trunc_dindirect(inode, UFS_NDADDR + 
+			uspi->s_apb + ((i + 1) << uspi->s_2apbshift), tind);
+		ubh_mark_buffer_dirty(tind_bh, 1);
+	}
+	for (i = 0; i < uspi->s_apb; i++)
+		if (SWAB32(*ubh_get_addr32 (tind_bh, i)))
+			break;
+	if (i >= uspi->s_apb) {
+		if (ubh_max_bcount(tind_bh) != 1)
+			retry = 1;
+		else {
+			tmp = SWAB32(*p);
+			*p = SWAB32(0);
+			inode->i_blocks -= uspi->s_nspb;
+			mark_inode_dirty(inode);
+			ufs_free_blocks (inode, tmp, uspi->s_fpb);
+			ubh_bforget(tind_bh);
+			tind_bh = NULL;
+		}
+	}
+	if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) {
+		ubh_ll_rw_block (WRITE, 1, &tind_bh);
+		ubh_wait_on_buffer (tind_bh);
+	}
+	ubh_brelse (tind_bh);
+	
+	UFSD(("EXIT\n"))
+	return retry;
+}
+		
+void ufs_truncate (struct inode * inode)
+{
+	struct super_block * sb;
+	struct ufs_sb_private_info * uspi;
+	struct buffer_head * bh;
+	unsigned offset;
+	int err, retry;
+	
+	UFSD(("ENTER\n"))
+	sb = inode->i_sb;
+	uspi = sb->u.ufs_sb.s_uspi;
+
+	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
+		return;
+	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+		return;
+	while (1) {
+		retry = ufs_trunc_direct(inode);
+		retry |= ufs_trunc_indirect (inode, UFS_IND_BLOCK,
+			(u32 *) &inode->u.ufs_i.i_u1.i_data[UFS_IND_BLOCK]);
+		retry |= ufs_trunc_dindirect (inode, UFS_IND_BLOCK + uspi->s_apb,
+			(u32 *) &inode->u.ufs_i.i_u1.i_data[UFS_DIND_BLOCK]);
+		retry |= ufs_trunc_tindirect (inode);
+		if (!retry)
+			break;
+		if (IS_SYNC(inode) && (inode->i_state & I_DIRTY))
+			ufs_sync_inode (inode);
+		current->counter = 0;
+		schedule ();
+
+
+	}
+	offset = inode->i_size & uspi->s_fshift;
+	if (offset) {
+		bh = ufs_bread (inode, inode->i_size >> uspi->s_fshift, 0, &err);
+		if (bh) {
+			memset (bh->b_data + offset, 0, uspi->s_fsize - offset);
+			mark_buffer_dirty (bh, 0);
+			brelse (bh);
+		}
+	}
+	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+	inode->u.ufs_i.i_lastfrag = howmany (inode->i_size, uspi->s_fsize);
+	mark_inode_dirty(inode);
+	UFSD(("EXIT\n"))
+}