• Steve French's avatar
    Add reflink copy over SMB3.11 with new FSCTL_DUPLICATE_EXTENTS · 02b16665
    Steve French authored
     Getting fantastic copy performance with cp --reflink over SMB3.11
     using the new FSCTL_DUPLICATE_EXTENTS.
    
     This FSCTL was added in the SMB3.11 dialect (testing was
     against REFS file system) so have put it as a 3.11 protocol
     specific operation ("vers=3.1.1" on the mount).  Tested at
     the SMB3 plugfest in Redmond.
    
     It depends on the new FS Attribute (BLOCK_REFCOUNTING) which
     is used to advertise support for the ability to do this ioctl
     (if you can support multiple files pointing to the same block
     than this refcounting ability or equivalent is needed to
     support the new reflink-like duplicate extent SMB3 ioctl.
    Signed-off-by: default avatarSteve French <steve.french@primarydata.com>
    02b16665
smbfsctl.h 6.4 KB