[U-Boot-Users] WARNING: in ext2fs.c

Roberts, John john.e.roberts at siemens.com
Thu Sep 29 21:47:40 CEST 2005

	In function: ext2fs_read_file(ext2fs_node_t node, int pos, unsigned
int len, char *buf)

	You may not be getting all the bytes you requested in the 'len'
parameter. Your requested length might be improperly adjusted.
	----------------------- Code snippet -------------
	unsigned int filesize = node->inode.size;

	/* Adjust len so it we can't read past the end of the file.  */
	if (len > filesize) {
	len = filesize;

"len" is the native requested size, while "filesize" is the files real size,
but byte-swapped and the two are being compared. As long as the byte-swapped
length value is larger than the requested size value, then you'll never have
a problem.

Now assume the file is 2meg and you requested 2meg.

IF(  len=200000 (2meg)    >  filesize=2000(2meg byte-swapped) )
THEN	len = filesize

You end up getting only 2000 bytes.

	The initialization of filesize should be:
	 unsigned int filesize = __le32_to_cpu (node->inode.size);
	unsigned int filesize = node->inode.size;

	-John Roberts

More information about the U-Boot mailing list