lkml.org 
[lkml]   [1998]   [Dec]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: scary ext2 filesystem question


    On Sun, 27 Dec 1998, Alan Cox wrote:

    > > the overhead was below 5% *in initial implementation*. Overhead compared
    > > to async variant, that is. It can be done for Linux implementation but
    > > we'll have to clean the VFS stuff up before.
    >
    > Stephen is doing full journalling.
    >
    > > are not independent. If we want to guarantee that on-disk copy is
    > > consistent at any moment we must submit these changes in _some_ order. The
    >
    > No order provides total consistency without a journalling log as far as I can
    > tell. Please provide an ordering example for extending a file that does not
    > either expose unwritten blocks to the user (security failure) or potentially
    > have to go and clean a block up afterwards
    >
    > Alan

    Erm... What I really wonder is how much would we lose on the following
    policy:
    Request 1: <write new data block>, depends on <>
    Request 2: <write new indirect block> or <add a pointer to existing one>,
    depends on <1>
    Request 3: <update inode block>, depends on <2>.
    In the worst case it will give us lost block, not attached to
    anything. BFD.
    With the current ext2 + bdflush we can get _any_ order at all,
    AFAI can see.
    Al



    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.rutgers.edu
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 13:46    [W:0.029 / U:0.300 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site