Re: [fuse-devel] storing the file handle in open()...?

[Franco B. <fr...@fu...>]

It does work, that's exactly how I use FUSE.


In the open routine do:

	res = open(path, flags);
	fi->fh = res;

And in the read routine do:

	int fd = fi->fh;

	res = pread(fd, buf, size, offset);






On Fri, 2006-01-13 at 11:16 +0100, Bjorn Lalin wrote:
> Hello,
> 
> I was simply wondering if there is a reason to store the file handle
> of 
> the open() wrapper when making a file system.
> 
> The thing is a wanna make a wrapper filesystem with some logging, 
> and it seems expensive to do an open() + read() + close() on every
> read performed (what is being done in the example filesystem given 
> with fuse). Or? The thing is I made a small test to log all calls into
> the fuse_operations struct to a file, printing all arguments given
> etc. and
> then simply mounting the fs and doing an 
> 
> echo "test" > testfile
> 
> I then took a look at the logfile and the ->fh field of the struct
> fuse_file_info 
> passed into the read call, and discovered that the file handle I
> stored in the 
> open() code is not there anymore.
> 
> However when release is called I get the correct file handle integer
> passed 
> in the struct.
> 
> Can anyone explain to me what is going on here, and how to code the
> open(),
> read(), write(), and release() correctly?
> 
> best regards,
> Bjorn