patch-2.3.17 linux/fs/udf/truncate.c

• Lines: 230
• Date: Sat Sep 4 12:42:30 1999
• Orig file: v2.3.16/linux/fs/udf/truncate.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.16/linux/fs/udf/truncate.c linux/fs/udf/truncate.c
@@ -0,0 +1,229 @@
+/*
+ * truncate.c
+ *
+ * PURPOSE
+ *	Truncate handling routines for the OSTA-UDF(tm) filesystem.
+ *
+ * CONTACTS
+ *	E-mail regarding any portion of the Linux UDF file system should be
+ *	directed to the development team mailing list (run by majordomo):
+ *		linux_udf@hootie.lvld.hp.com
+ *
+ * COPYRIGHT
+ *	This file is distributed under the terms of the GNU General Public
+ *	License (GPL). Copies of the GPL can be obtained from:
+ *		ftp://prep.ai.mit.edu/pub/gnu/GPL
+ *	Each contributing author retains all rights to their own work.
+ *
+ *  (C) 1999 Ben Fennema
+ *  (C) 1999 Stelias Computing Inc
+ *
+ * HISTORY
+ *
+ *  02/24/99 blf  Created.
+ *
+ */
+
+#include "udfdecl.h"
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/udf_fs.h>
+
+#include "udf_i.h"
+#include "udf_sb.h"
+
+static void extent_trunc(struct inode * inode, lb_addr bloc, int *extoffset,
+	lb_addr eloc, Uint32 elen, struct buffer_head **bh, Uint32 offset)
+{
+	lb_addr neloc = { 0, 0 };
+	int nelen = 0;
+	int blocks = inode->i_sb->s_blocksize / 512;
+	int last_block = (elen + inode->i_sb->s_blocksize - 1) / inode->i_sb->s_blocksize;
+
+
+	if (offset)
+	{
+		nelen = ((offset - 1) << inode->i_sb->s_blocksize_bits) +
+			(inode->i_size & (inode->i_sb->s_blocksize - 1));
+		neloc = eloc;
+	}
+
+	inode->i_blocks -= (blocks * (last_block - offset));
+	udf_write_aext(inode, bloc, extoffset, neloc, nelen, bh, 1);
+	if (!memcmp(&UDF_I_EXT0LOC(inode), &eloc, sizeof(lb_addr)))
+	{
+		UDF_I_EXT0LOC(inode) = neloc;
+		UDF_I_EXT0LEN(inode) = nelen;
+	}
+	mark_inode_dirty(inode);
+	udf_free_blocks(inode, eloc, offset, last_block - offset);
+}
+
+static void trunc(struct inode * inode)
+{
+	lb_addr bloc, eloc, neloc = { 0, 0 };
+	Uint32 extoffset, elen, offset, nelen = 0, lelen = 0, lenalloc;
+	int etype;
+	int first_block = (inode->i_size + inode->i_sb->s_blocksize - 1) / inode->i_sb->s_blocksize;
+	struct buffer_head *bh = NULL;
+	int adsize;
+
+	if (UDF_I_ALLOCTYPE(inode) == ICB_FLAG_AD_SHORT)
+		adsize = sizeof(short_ad);
+	else if (UDF_I_ALLOCTYPE(inode) == ICB_FLAG_AD_LONG)
+		adsize = sizeof(long_ad);
+	else
+		adsize = 0;
+
+	if ((etype = inode_bmap(inode, first_block, &bloc, &extoffset, &eloc, &elen, &offset, &bh)) != -1)
+	{
+		extoffset -= adsize;
+		extent_trunc(inode, bloc, &extoffset, eloc, elen, &bh, offset);
+
+		if (offset)
+			lenalloc = extoffset;
+		else
+			lenalloc = extoffset - adsize;
+
+		if (!memcmp(&UDF_I_LOCATION(inode), &bloc, sizeof(lb_addr)))
+			lenalloc -= udf_file_entry_alloc_offset(inode);
+		else
+			lenalloc -= sizeof(struct AllocExtDesc);
+
+		while ((etype = udf_current_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 0)) != -1)
+		{
+			if (etype == EXTENT_NEXT_EXTENT_ALLOCDECS)
+			{
+				udf_write_aext(inode, bloc, &extoffset, neloc, nelen, &bh, 0);
+				extoffset = 0;
+				if (lelen)
+				{
+					if (!memcmp(&UDF_I_LOCATION(inode), &bloc, sizeof(lb_addr)))
+						memset(bh->b_data, 0x00, udf_file_entry_alloc_offset(inode));
+					else
+						memset(bh->b_data, 0x00, sizeof(struct AllocExtDesc));
+					udf_free_blocks(inode, bloc, 0, lelen);
+				}
+				else
+				{
+					if (!memcmp(&UDF_I_LOCATION(inode), &bloc, sizeof(lb_addr)))
+						UDF_I_LENALLOC(inode) = lenalloc;
+					else
+					{
+						struct AllocExtDesc *aed = (struct AllocExtDesc *)(bh->b_data);
+						aed->lengthAllocDescs = cpu_to_le32(lenalloc);
+					}
+				}
+
+				udf_release_data(bh);
+				bh = NULL;
+
+				bloc = eloc;
+				if (elen)
+					lelen = (elen + inode->i_sb->s_blocksize - 1) >>
+						inode->i_sb->s_blocksize_bits;
+				else
+					lelen = 1;
+			}
+			else if (etype != EXTENT_NOT_RECORDED_NOT_ALLOCATED)
+				extent_trunc(inode, bloc, &extoffset, eloc, elen, &bh, 0);
+			else
+				udf_write_aext(inode, bloc, &extoffset, neloc, nelen, &bh, 1);
+		}
+
+		if (lelen)
+		{
+			if (!memcmp(&UDF_I_LOCATION(inode), &bloc, sizeof(lb_addr)))
+				memset(bh->b_data, 0x00, udf_file_entry_alloc_offset(inode));
+			else
+				memset(bh->b_data, 0x00, sizeof(struct AllocExtDesc));
+			udf_free_blocks(inode, bloc, 0, lelen);
+		}
+		else
+		{
+			if (!memcmp(&UDF_I_LOCATION(inode), &bloc, sizeof(lb_addr)))
+				UDF_I_LENALLOC(inode) = lenalloc;
+			else
+			{
+				struct AllocExtDesc *aed = (struct AllocExtDesc *)(bh->b_data);
+				aed->lengthAllocDescs = cpu_to_le32(lenalloc);
+			}
+		}
+	}
+	else if (inode->i_size)
+	{
+		lb_addr e0loc = UDF_I_LOCATION(inode);
+		Uint32 ext0offset = udf_file_entry_alloc_offset(inode);
+		char tetype;
+
+		if (offset)
+		{
+			extoffset -= adsize;
+			tetype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1);
+			if (tetype == EXTENT_NOT_RECORDED_NOT_ALLOCATED)
+			{
+				extoffset -= adsize;
+				elen = (EXTENT_NOT_RECORDED_NOT_ALLOCATED << 30) |
+					(elen + (offset << inode->i_sb->s_blocksize_bits));
+				if (ext0offset == extoffset && !memcmp(&e0loc, &bloc, sizeof(lb_addr)))
+					UDF_I_EXT0LEN(inode) = elen;
+				udf_write_aext(inode, bloc, &extoffset, eloc, elen, &bh, 0);
+			}
+			else
+			{
+				if (elen & (inode->i_sb->s_blocksize - 1))
+				{
+					extoffset -= adsize;
+					elen = (EXTENT_RECORDED_ALLOCATED << 30) |
+						((elen + inode->i_sb->s_blocksize - 1) &
+						~(inode->i_sb->s_blocksize - 1));
+					if (ext0offset == extoffset && !memcmp(&e0loc, &bloc, sizeof(lb_addr)))
+						UDF_I_EXT0LEN(inode) = elen;
+					udf_write_aext(inode, bloc, &extoffset, eloc, elen, &bh, 1);
+				}
+				memset(&eloc, 0x00, sizeof(lb_addr));
+				elen = (EXTENT_NOT_RECORDED_NOT_ALLOCATED << 30) |
+					(offset << inode->i_sb->s_blocksize_bits);
+				if (ext0offset == extoffset && !memcmp(&e0loc, &bloc, sizeof(lb_addr)))
+				{
+					UDF_I_EXT0LOC(inode) = eloc;
+					UDF_I_EXT0LEN(inode) = elen;
+				}
+				udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1);
+			}
+		}
+	}
+
+	udf_release_data(bh);
+}
+
+void udf_truncate(struct inode * inode)
+{
+	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;
+
+	if (!UDF_I_EXT0OFFS(inode))
+	{
+		udf_discard_prealloc(inode);
+
+		trunc(inode);
+	}
+
+	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+	mark_inode_dirty(inode);
+}
+
+void udf_truncate_adinicb(struct inode * inode)
+{
+	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;
+
+	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+	mark_inode_dirty(inode);
+}