Date: Sat, 11 Sep 2010 20:41:22 -0400 (EDT) From: Rick Macklem <rmacklem@uoguelph.ca> To: Kostik Belousov <kostikbel@gmail.com> Cc: svn-src-head@freebsd.org, Rick Macklem <rmacklem@freebsd.org>, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r212439 - head/sys/fs/nfs Message-ID: <1300087421.776986.1284252082593.JavaMail.root@erie.cs.uoguelph.ca> In-Reply-To: <20100911060111.GT2465@deviant.kiev.zoral.com.ua>
next in thread | previous in thread | raw e-mail | index | archive | help
> Then, fid_reserved is no more reserved ? Should we rename it ?
>
> Comment for fid_reserved about longword alignment is wrong.
Well, it's actually more broken than that.
fid_len - Most file systems set it to the size of their variant
of the entire structure, including the Xfid_len field.
ZFS sets it to the size of the structure - sizeof(uint16_t)
{ presumably subtracting out the size if Xfid_len? }.
And xfs, well, it does weird stuff with it I can't figure
out, but it is definitely not the size of the entire struct.
As such, exposing fid_len above the VOP_xxx() doesn't make much sense.
(After my commit yesterday, nothing above the VOP_VPTOFH() uses it.)
Personally, I'd lean towards a generic struct fid like...
struct fid {
uint8_t fid_data[MAXFIDSZ];
};
with MAXFIDSZ increased appropriately, but this will require changes
to xfs and zfs, since they both set the generic fid_len.
If you go with...
struct fid {
uint16_t fid_len;
uint8_t fid_data[MAXFIDSZ];
};
then the hash functions in the two NFS servers need to be changed
(they assume 32bit alignment of fid_data), but they should be fixed
anyhow, since they mostly hash to 0 for ZFS at this time. (From what
I see ZFS file handles looking like.)
Or, you could just rename fid_reserved to fid_pad and not worry about it.
Maybe the ZFS folks could decide what they would prefer? rick
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1300087421.776986.1284252082593.JavaMail.root>