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    Subject[086/262] md/raid5: fix bug that could result in reads from a failed device.
    3.0-stable review patch.  If anyone has any objections, please let me know.


    From: NeilBrown <>

    commit 355840e7a7e56bb2834fd3b0da64da5465f8aeaa upstream.

    This bug was introduced in 415e72d034c50520ddb7ff79e7d1792c1306f0c9
    which was in 2.6.36.

    There is a small window of time between when a device fails and when
    it is removed from the array. During this time we might still read
    from it, but we won't write to it - so it is possible that we could
    read stale data.

    We didn't need the test of 'Faulty' before because the test on
    In_sync is sufficient. Since we started allowing reads from the early
    part of non-In_sync devices we need a test on Faulty too.

    This is suitable for any kernel from 2.6.36 onwards, though the patch
    might need a bit of tweaking in 3.0 and earlier.

    Signed-off-by: NeilBrown <>
    Signed-off-by: Greg Kroah-Hartman <>

    drivers/md/raid5.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    --- a/drivers/md/raid5.c
    +++ b/drivers/md/raid5.c
    @@ -3369,7 +3369,7 @@ static void handle_stripe6(struct stripe
    /* Not in-sync */;
    else if (test_bit(In_sync, &rdev->flags))
    set_bit(R5_Insync, &dev->flags);
    - else {
    + else if (!test_bit(Faulty, &rdev->flags)) {
    /* in sync if before recovery_offset */
    if (sh->sector + STRIPE_SECTORS <= rdev->recovery_offset)
    set_bit(R5_Insync, &dev->flags);

     \ /
      Last update: 2011-11-10 06:19    [W:0.020 / U:112.672 seconds]
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