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    Subject[patch 07/47] md: Dont acknowlege that stripe-expand is complete until it really is.
    2.6.25-stable review patch.  If anyone has any objections, please let us
    know.

    ------------------
    From: Neil Brown <neilb@notabene.brown>

    commit efe311431869b40d67911820a309f9a1a41306f3 upstream

    We shouldn't acknowledge that a stripe has been expanded (When
    reshaping a raid5 by adding a device) until the moved data has
    actually been written out. However we are currently
    acknowledging (by calling md_done_sync) when the POST_XOR
    is complete and before the write.

    So track in s.locked whether there are pending writes, and don't
    call md_done_sync yet if there are.

    Note: we all set R5_LOCKED on devices which are are about to
    read from. This probably isn't technically necessary, but is
    usually done when writing a block, and justifies the use of
    s.locked here.

    This bug can lead to a crash if an array is stopped while an reshape
    is in progress.

    Signed-off-by: Neil Brown <neilb@suse.de>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

    ---
    drivers/md/raid5.c | 3 +++
    1 file changed, 3 insertions(+)

    --- a/drivers/md/raid5.c
    +++ b/drivers/md/raid5.c
    @@ -2861,6 +2861,8 @@ static void handle_stripe5(struct stripe

    for (i = conf->raid_disks; i--; ) {
    set_bit(R5_Wantwrite, &sh->dev[i].flags);
    + set_bit(R5_LOCKED, &dev->flags);
    + s.locked++;
    if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
    sh->ops.count++;
    }
    @@ -2874,6 +2876,7 @@ static void handle_stripe5(struct stripe
    conf->raid_disks);
    s.locked += handle_write_operations5(sh, 1, 1);
    } else if (s.expanded &&
    + s.locked == 0 &&
    !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) {
    clear_bit(STRIPE_EXPAND_READY, &sh->state);
    atomic_dec(&conf->reshape_stripes);
    --


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