From e6620be16de9d74017d0cc4095a2ca1f034e85ed Mon Sep 17 00:00:00 2001
From: Yura Pakhuchiy <pakhuchiy@gmail.com>
Date: Fri, 8 Jun 2007 13:35:47 +0300
Subject: [PATCH] Do not create holes in ntfs_attr_pwrite that will be
 instantiated right after creation

* Add new API: __ntfs_attr_truncate that allow user to select whether holes should be created or clusters allocated
* Update ntfs_attr_pwrite and ntfscp to use it.
---
 include/ntfs/attrib.h |  1 +
 libntfs/attrib.c      | 27 +++++++++++++++++++++------
 ntfsprogs/ntfscp.c    |  6 +++---
 3 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/include/ntfs/attrib.h b/include/ntfs/attrib.h
index a1502c99..2daee4d6 100644
--- a/include/ntfs/attrib.h
+++ b/include/ntfs/attrib.h
@@ -315,6 +315,7 @@ extern int ntfs_attr_record_move_away(ntfs_attr_search_ctx *ctx, int extra);
 
 extern int ntfs_attr_update_mapping_pairs(ntfs_attr *na, VCN from_vcn);
 
+extern int __ntfs_attr_truncate(ntfs_attr *na, const s64 newsize, BOOL sparse);
 extern int ntfs_attr_truncate(ntfs_attr *na, const s64 newsize);
 
 extern int ntfs_attr_exist(ntfs_inode *ni, const ATTR_TYPES type,
diff --git a/libntfs/attrib.c b/libntfs/attrib.c
index 6bdf7cd8..4864db54 100644
--- a/libntfs/attrib.c
+++ b/libntfs/attrib.c
@@ -986,7 +986,7 @@ s64 ntfs_attr_pwrite(ntfs_attr *na, const s64 pos, s64 count, const void *b)
 	/* If the write reaches beyond the end, extend the attribute. */
 	old_data_size = na->data_size;
 	if (pos + count > na->data_size) {
-		if (ntfs_attr_truncate(na, pos + count)) {
+		if (__ntfs_attr_truncate(na, pos + count, FALSE)) {
 			eo = errno;
 			ntfs_log_trace("Attribute extend failed.\n");
 			errno = eo;
@@ -4698,6 +4698,7 @@ put_err_out:
  * ntfs_non_resident_attr_expand - expand a non-resident, open ntfs attribute
  * @na:		non-resident ntfs attribute to expand
  * @newsize:	new size (in bytes) to which to expand the attribute
+ * @sparse:	if TRUE then will create hole if possible
  *
  * Expand the size of a non-resident, open ntfs attribute @na to @newsize bytes,
  * by allocating new clusters.
@@ -4708,7 +4709,8 @@ put_err_out:
  *	ERANGE - @newsize is not valid for the attribute type of @na.
  *	ENOSPC - There is no enough space in base mft to resize $ATTRIBUTE_LIST.
  */
-static int ntfs_non_resident_attr_expand(ntfs_attr *na, const s64 newsize)
+static int ntfs_non_resident_attr_expand(ntfs_attr *na, const s64 newsize,
+		BOOL sparse)
 {
 	LCN lcn_seek_from;
 	VCN first_free_vcn;
@@ -4758,7 +4760,7 @@ static int ntfs_non_resident_attr_expand(ntfs_attr *na, const s64 newsize)
 		 * If we extend $DATA attribute on NTFS 3+ volume, we can add
 		 * sparse runs instead of real allocation of clusters.
 		 */
-		if (na->type == AT_DATA && vol->major_ver >= 3) {
+		if (na->type == AT_DATA && vol->major_ver >= 3 && sparse) {
 			rl = ntfs_malloc(0x1000);
 			if (!rl)
 				return -1;
@@ -4903,10 +4905,12 @@ put_err_out:
 	return -1;
 }
 
+
 /**
- * ntfs_attr_truncate - resize an ntfs attribute
+ * __ntfs_attr_truncate - resize an ntfs attribute
  * @na:		open ntfs attribute to resize
  * @newsize:	new size (in bytes) to which to resize the attribute
+ * @sparse:	if TRUE then will create hole if possible
  *
  * Change the size of an open ntfs attribute @na to @newsize bytes. If the
  * attribute is made bigger and the attribute is resident the newly
@@ -4926,7 +4930,7 @@ put_err_out:
  *			  @newsize bytes length.
  *	EOPNOTSUPP	- The desired resize is not implemented yet.
  */
-int ntfs_attr_truncate(ntfs_attr *na, const s64 newsize)
+int __ntfs_attr_truncate(ntfs_attr *na, const s64 newsize, BOOL sparse)
 {
 	int ret;
 
@@ -4959,7 +4963,8 @@ int ntfs_attr_truncate(ntfs_attr *na, const s64 newsize)
 	}
 	if (NAttrNonResident(na)) {
 		if (newsize > na->data_size)
-			ret = ntfs_non_resident_attr_expand(na, newsize);
+			ret = ntfs_non_resident_attr_expand(na, newsize,
+					sparse);
 		else
 			ret = ntfs_non_resident_attr_shrink(na, newsize);
 	} else
@@ -4971,6 +4976,16 @@ int ntfs_attr_truncate(ntfs_attr *na, const s64 newsize)
 	return ret;
 }
 
+
+/**
+ * Wrapper around __ntfs_attr_truncate that always tries to creates hole
+ */
+int ntfs_attr_truncate(ntfs_attr *na, const s64 newsize)
+{
+	return __ntfs_attr_truncate(na, newsize, TRUE);
+}
+
+
 /**
  * ntfs_attr_readall - read the entire data from an ntfs attribute
  * @ni:		open ntfs inode in which the ntfs attribute resides
diff --git a/ntfsprogs/ntfscp.c b/ntfsprogs/ntfscp.c
index b7a96927..72af5a96 100644
--- a/ntfsprogs/ntfscp.c
+++ b/ntfsprogs/ntfscp.c
@@ -1,7 +1,7 @@
 /**
  * ntfscp - Part of the Linux-NTFS project.
  *
- * Copyright (c) 2004-2006 Yura Pakhuchiy
+ * Copyright (c) 2004-2007 Yura Pakhuchiy
  * Copyright (c) 2005 Anton Altaparmakov
  * Copyright (c) 2006 Hil Liao
  *
@@ -85,7 +85,7 @@ static void version(void)
 {
 	ntfs_log_info("\n%s v%s (libntfs %s) - Overwrite files on NTFS "
 		"volume.\n\n", EXEC_NAME, VERSION, ntfs_libntfs_version());
-	ntfs_log_info("Copyright (c) 2004-2006 Yura Pakhuchiy\n");
+	ntfs_log_info("Copyright (c) 2004-2007 Yura Pakhuchiy\n");
 	ntfs_log_info("\n%s\n%s%s\n", ntfs_gpl, ntfs_bugs, ntfs_home);
 }
 
@@ -524,7 +524,7 @@ int main(int argc, char *argv[])
 
 	ntfs_log_verbose("Old file size: %lld\n", na->data_size);
 	if (na->data_size != new_size) {
-		if (ntfs_attr_truncate(na, new_size)) {
+		if (__ntfs_attr_truncate(na, new_size, FALSE)) {
 			ntfs_log_perror("ERROR: Couldn't resize attribute");
 			goto close_attr;
 		}