[PATCH] [SMB3] Allow mknod and mkfifo on SMB2/SMB3 mounts

[Steve French]

The "sfu" mount option did not work on SMB2/SMB3 mounts.
With these changes when the "sfu" mount option is passed in
on an smb2/smb2.1/smb3 mount the client can emulate (and
recognize) fifo and device (character and device files).

In addition the "sfu" mount option should not conflict
with "mfsymlinks" (symlink emulation) as we will never
create "sfu" style symlinks, but using "sfu" mount option
will allow us to recognize existing symlinks, created with
Microsoft "Services for Unix" (SFU and SUA).

To enable the "sfu" mount option for SMB2/SMB3 the calling
syntax of the generic cifs/smb2/smb3 sync_read and sync_write
protocol dependent function needed to be changed (we
don't have a file struct in all cases), but this actually
ended up simplifying the code a little.

Patch attached and also at:

http://git.samba.org/?p=sfrench/cifs-2.6.git;a=shortlog;h=refs/heads/for-next

[Steve French]

This fixes xfstest generic/184 on smb3 mounts

Post by Steve French
The "sfu" mount option did not work on SMB2/SMB3 mounts.
With these changes when the "sfu" mount option is passed in
on an smb2/smb2.1/smb3 mount the client can emulate (and
recognize) fifo and device (character and device files).
In addition the "sfu" mount option should not conflict
with "mfsymlinks" (symlink emulation) as we will never
create "sfu" style symlinks, but using "sfu" mount option
will allow us to recognize existing symlinks, created with
Microsoft "Services for Unix" (SFU and SUA).
To enable the "sfu" mount option for SMB2/SMB3 the calling
syntax of the generic cifs/smb2/smb3 sync_read and sync_write
protocol dependent function needed to be changed (we
don't have a file struct in all cases), but this actually
ended up simplifying the code a little.
http://git.samba.org/?p=sfrench/cifs-2.6.git;a=shortlog;h=refs/heads/for-next
--
Thanks,
Steve

[Christoph Hellwig]

Is there any good reason to require a mount option for these extensions?

[Steve French]

I am ok with not requiring a mount option (at least for smb3) with the
goal of making these more intuitive. For cifs mounts, perhaps better
not to change existing behavior.

Post by Christoph Hellwig
Is there any good reason to require a mount option for these extensions?