* Fixed a big bug in common_file_io_vec_pages(): vecOffset was not correctly

set when the first chunk of the file could be read in directly, causing it
  to read data to a wrong place in the buffer.
* Reading in the first chunk directly would have also only worked if vecIndex
  and vecOffset was 0 when calling the function.
* Applied the fs_shell changes in file_map to the kernel version as well (the
  constructor already worked correctly, though).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23265 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/kernel/cache/file_map.cpp

@@ -253,7 +253,7 @@ file_map_translate(void *_map, off_t offset, size_t size, file_io_vec *vecs,
 	size_t maxVecs = *_count;
 	status_t status = B_OK;
 
-	if (offset > map.size) {
+	if (offset >= map.size) {
 		*_count = 0;
 		return B_OK;
 	}

src/system/kernel/fs/vfs.cpp

@@ -2594,7 +2594,7 @@ common_file_io_vec_pages(struct vnode *vnode, void *cookie,
 	status_t status;
 	size_t size;
 
-	if (!doWrite) {
+	if (!doWrite && vecOffset == 0) {
 		// now directly read the data from the device
 		// the first file_io_vec can be read directly
 
@@ -2603,8 +2603,8 @@ common_file_io_vec_pages(struct vnode *vnode, void *cookie,
 			size = numBytes;
 
 		status = FS_CALL(vnode, read_pages)(vnode->mount->cookie,
-			vnode->private_node, cookie, fileVecs[0].offset, vecs, vecCount,
-			&size, false);
+			vnode->private_node, cookie, fileVecs[0].offset, &vecs[vecIndex],
+			vecCount - vecIndex, &size, false);
 		if (status < B_OK)
 			return status;
 
@@ -2636,9 +2636,11 @@ common_file_io_vec_pages(struct vnode *vnode, void *cookie,
 		for (; vecIndex < vecCount; vecIndex++) {
 			if (size < vecs[vecIndex].iov_len)
 				break;
-	
+
 			size -= vecs[vecIndex].iov_len;
 		}
+
+		vecOffset = size;
 	} else {
 		fileVecIndex = 0;
 		size = 0;

src/tools/fs_shell/vfs.cpp

@@ -1749,7 +1749,7 @@ common_file_io_vec_pages(int fd, const fssh_file_io_vec *fileVecs,
 	fssh_status_t status;
 	fssh_size_t size;
 
-	if (!doWrite) {
+	if (!doWrite && vecOffset == 0) {
 		// now directly read the data from the device
 		// the first file_io_vec can be read directly
 
@@ -1757,8 +1757,8 @@ common_file_io_vec_pages(int fd, const fssh_file_io_vec *fileVecs,
 		if (size > numBytes)
 			size = numBytes;
 
-		status = fssh_read_pages(fd, fileVecs[0].offset, vecs, vecCount,
-			&size, false);
+		status = fssh_read_pages(fd, fileVecs[0].offset, &vecs[vecIndex],
+			vecCount - vecIndex, &size, false);
 		if (status < FSSH_B_OK)
 			return status;
 
@@ -1790,9 +1790,11 @@ common_file_io_vec_pages(int fd, const fssh_file_io_vec *fileVecs,
 		for (; vecIndex < vecCount; vecIndex++) {
 			if (size < vecs[vecIndex].iov_len)
 				break;
-	
+
 			size -= vecs[vecIndex].iov_len;
 		}
+
+		vecOffset = size;
 	} else {
 		fileVecIndex = 0;
 		size = 0;