• Steve French's avatar
    [CIFS] add mount option to send mandatory rather than advisory locks · 13a6e42a
    Steve French authored
    Some applications/subsystems require mandatory byte range locks
    (as is used for Windows/DOS/OS2 etc). Sending advisory (posix style)
    byte range lock requests (instead of mandatory byte range locks) can
    lead to problems for these applications (which expect that other
    clients be prevented from writing to portions of the file which
    they have locked and are updating).  This mount option allows
    mounting cifs with the new mount option "forcemand" (or
    "forcemandatorylock") in order to have the cifs client use mandatory
    byte range locks (ie SMB/CIFS/Windows/NTFS style locks) rather than
    posix byte range lock requests, even if the server would support
    posix byte range lock requests.  This has no effect if the server
    does not support the CIFS Unix Extensions (since posix style locks
    require support for the CIFS Unix Extensions), but for mounts
    to Samba servers this can be helpful for Wine and applications
    that require mandatory byte range locks.
    Acked-by: default avatarJeff Layton <jlayton@redhat.com>
    CC: Alexander Bokovoy <ab@samba.org>
    Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
    13a6e42a
cifsfs.h 4.79 KB