From d0a2e7d3a28b25f333a24fac0ded40544e0d05ed Mon Sep 17 00:00:00 2001
From: szaka <szaka>
Date: Tue, 12 Dec 2006 23:16:43 +0000
Subject: [PATCH] ntfs_read/ntfs_write: use pread/pwrite => 2-8% speed increase
 (Henk, Szaka)

---
 libntfs-3g/device.c  | 23 ++++++++---------------
 libntfs-3g/unix_io.c |  4 ++--
 2 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/libntfs-3g/device.c b/libntfs-3g/device.c
index afdfbcd2..e1170825 100644
--- a/libntfs-3g/device.c
+++ b/libntfs-3g/device.c
@@ -179,22 +179,18 @@ s64 ntfs_pread(struct ntfs_device *dev, const s64 pos, s64 count, void *b)
 	struct ntfs_device_operations *dops;
 
 	ntfs_log_trace("Entering for pos 0x%llx, count 0x%llx.\n", pos, count);
+	
 	if (!b || count < 0 || pos < 0) {
 		errno = EINVAL;
 		return -1;
 	}
 	if (!count)
 		return 0;
+	
 	dops = dev->d_ops;
-	/* Locate to position. */
-	if (dops->seek(dev, pos, SEEK_SET) == (off_t)-1) {
-		ntfs_log_perror("ntfs_pread: device seek to 0x%llx returned error",
-				pos);
-		return -1;
-	}
-	/* Read the data. */
+
 	for (total = 0; count; count -= br, total += br) {
-		br = dops->read(dev, (char*)b + total, count);
+		br = dops->pread(dev, (char*)b + total, count, pos + total);
 		/* If everything ok, continue. */
 		if (br > 0)
 			continue;
@@ -244,16 +240,13 @@ s64 ntfs_pwrite(struct ntfs_device *dev, const s64 pos, s64 count,
 		errno = EROFS;
 		goto out;
 	}
+	
 	dops = dev->d_ops;
-	/* Locate to position. */
-	if (dops->seek(dev, pos, SEEK_SET) == (off_t)-1) {
-		ntfs_log_perror("ntfs_pwrite: seek to 0x%llx returned error",
-				pos);
-		goto out;
-	}
+
 	NDevSetDirty(dev);
 	for (total = 0; count; count -= written, total += written) {
-		written = dops->write(dev, (const char*)b + total, count);
+		written = dops->pwrite(dev, (const char*)b + total, count,
+				       pos + total);
 		/* If everything ok, continue. */
 		if (written > 0)
 			continue;
diff --git a/libntfs-3g/unix_io.c b/libntfs-3g/unix_io.c
index 5f2c825b..78a09207 100644
--- a/libntfs-3g/unix_io.c
+++ b/libntfs-3g/unix_io.c
@@ -239,7 +239,7 @@ static s64 ntfs_device_unix_io_write(struct ntfs_device *dev, const void *buf,
 static s64 ntfs_device_unix_io_pread(struct ntfs_device *dev, void *buf,
 		s64 count, s64 offset)
 {
-	return ntfs_pread(dev, offset, count, buf);
+	return pread(DEV_FD(dev), buf, count, offset);
 }
 
 /**
@@ -261,7 +261,7 @@ static s64 ntfs_device_unix_io_pwrite(struct ntfs_device *dev, const void *buf,
 		return -1;
 	}
 	NDevSetDirty(dev);
-	return ntfs_pwrite(dev, offset, count, buf);
+	return pwrite(DEV_FD(dev), buf, count, offset);
 }
 
 /**