• NeilBrown's avatar
    [PATCH] knfsd: nfsd4: initialize recovery directory · 190e4fbf
    NeilBrown authored
    NFSv4 clients are required to know what state they have on the server so that
    they can reclaim it on server reboot.  However, it is possible for
    pathalogical combinations of server reboots and network partitions to leave a
    client in a state where it cannot know whether it has lost its state on the
    server.
    
    For this reason, rfc3530 requires that we store some information about clients
    to stable storage.
    
    So we maintain a directory /var/lib/nfs/v4recovery with a subdirectory for
    each client with active state.  We leave open the possibility of including
    files underneath each such subdirectory with information about the client, but
    for now the subdirectories are empty.
    
    We create a client subdirectory whenever a client makes its first non-reclaim
    open_confirm.
    
    We remove a client subdirectory whenever either
            a) its lease expires, or
    	b) the grace period ends without it reclaiming anything.
    When handling reclaims, we allow the reclaim if and only if the client doing
    the reclaim has a subdirectory.
    
    This patch adds just the code to scan the recovery directory on nfsd startup.
    Signed-off-by: default avatarAndy Adamson <andros@citi.umich.edu>
    Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
    Signed-off-by: default avatarNeil Brown <neilb@cse.unsw.edu.au>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    190e4fbf
nfs4state.c 87.4 KB