On Feb 1, 2008 2:14 AM, Andi Kleen <[EMAIL PROTECTED]> wrote: > Lars Noschinski <[EMAIL PROTECTED]> writes: > > > For an university project, we had to write a toy filesystem (ext2-like), > > for which I would like to implement sparse file support. For this, I > > digged through the ext2 source code; but I could not find the point, > > where ext2 detects holes. > > > > As far as I can see from fs/buffer.c, an hole is a buffer_head which is > > not mapped, but uptodate. But I cannot find a relevant source line, > > where ext2 makes usage of this information. > > It does not explicitely detect holes; holey data is just never written > so no space for it is allocated. >
does anybody know how to make a hole in a large file which already has real content from user space application? In my project I need this function to delete a piece of content from an exist large effectively. thanks. > -Andi > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to [EMAIL PROTECTED] > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/