• Steven Whitehouse's avatar
    GFS2: Support generation of discard requests · f15ab561
    Steven Whitehouse authored
    This patch allows GFS2 to generate discard requests for blocks which are
    no longer useful to the filesystem (i.e. those which have been freed as
    the result of an unlink operation). The requests are generated at the
    time which those blocks become available for reuse in the filesystem.
    
    In order to use this new feature, you have to specify the "discard"
    mount option. The code coalesces adjacent blocks into a single extent
    when generating the discard requests, thus generating the minimum
    number.
    
    If an error occurs when the request has been sent to the block device,
    then it will print a message and turn off the requests for that
    filesystem. If the problem is temporary, then you can use remount to
    turn the option back on again. There is also a nodiscard mount option
    so that you can use remount to turn discard requests off, if required.
    Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    f15ab561
ops_super.c 16.3 KB