Mail Archives: cygwin/2012/05/12/06:54:43
Hi Jeremy,
On May 11 14:15, Jeremy Allison wrote:
> On Fri, May 11, 2012 at 07:58:43PM +0200, Corinna Vinschen wrote:
> > On May 11 12:56, starlight DOT 2012q2 AT binnacle DOT cx wrote:
> > > /********************************************************************
> > > Create a 64 bit FileIndex. If the file is on the same device as
> > > the root of the share, just return the 64-bit inode. If it isn't,
> > > mangle as we used to do.
> > > ********************************************************************/
> > >
> > > uint64_t get_FileIndex(connection_struct *conn, const SMB_STRUCT_STAT *psbuf)
> > > {
> > > uint64_t file_index;
> > > if (conn->base_share_dev == psbuf->st_ex_dev) {
> > > return (uint64_t)psbuf->st_ex_ino;
> > > }
> > > file_index = ((psbuf->st_ex_ino) & UINT32_MAX); /* FileIndexLow */
> > > file_index |= ((uint64_t)((psbuf->st_ex_dev) & UINT32_MAX)) << 32; /* FileIndexHigh */
> > > return file_index;
> > > }
> >
> > Which Samba version introduced this behaviour? Originally, way back
> > when Samba 3.0.28 was new, the inode numbers were always mangled to be
> > 64 bit numbers, AFAIK. The code in Cygwin which doesn't trust 32 bit
> > inode numbers on remote drives is there for ages, at least since 2007.
> >
> > Fortunately we have an interface which allows to fetch the Samba version
> > number from the server since Samba 3.0.28a. So, if we know which Samba
> > version started to return the real 32 bit inode number, we can adapt.
> > [...]
> > inline bool
> > path_conv::isgood_inode (__ino64_t ino) const
> > {
> > /* We can't trust remote inode numbers of only 32 bit. That means,
> > remote NT4 NTFS, as well as shares of Samba version < 3.0.
> > The known exception are SFU NFS shares, which return the valid 32 bit
> > inode number from the remote file system unchanged. */
> > return hasgood_inode () && (ino > UINT32_MAX || !isremote () || fs_is_nfs ());
> > }
>
> The get_FileIndex() code has been there since at least 3.6.x, but
> I'll try and track down when it was first introduced.
That would be nice. For now, assuming the get_FileIndex has been
introduced with 3.6.0, I'd go with this new implementation, stretched
out and better comments for readability:
inline bool
path_conv::isgood_inode (__ino64_t ino) const
{
/* If the FS doesn't support nonambiguous inode numbers anyway, bail out
immediately. */
if (!hasgood_inode ())
return false;
/* If the inode numbers are 64 bit numbers or if it's a local FS, they
are to be trusted. */
if (ino > UINT32_MAX || !isremote ())
return true;
/* The inode numbers returned from a remote NT4 NTFS are ephemeral
32 bit numbers. */
if (fs_is_ntfs ())
return false;
/* Samba versions since 3.x.x return the real inode numbers, unless the file
is not on the same device as the root of the share, in which case Samba
returns a mangled inode number which is a 64 bit number again. See the
get_FileIndex function in the Samba sources. */
if (fs_is_samba () && fs.samba_version () >= 0x03060000)
return true;
/* SFU NFS just returns the actual inode number. */
if (fs_is_nfs ())
return true;
/* Otherwise, don't trust the inode numbers. */
return false;
}
What do you say?
Thanks,
Corinna
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Project Co-Leader cygwin AT cygwin DOT com
Red Hat
--
Problem reports: http://cygwin.com/problems.html
FAQ: http://cygwin.com/faq/
Documentation: http://cygwin.com/docs.html
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
- Raw text -