Messages in this thread | | | From | Dave Chinner <> | Subject | [PATCH 0/2] xfs: fix inode count underrun | Date | Wed, 6 May 2015 08:01:37 +1000 |
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Hi folks,
With the conversion of XFS to use the generic per-cpu superblocks, I overlooked the fact that the update batch size is important to the accuracy of the comparison function. Using different batch sizes means percpu_counter_compare() doesn't detect when it should fall back to percpu_counter_sum() for accuracy correctly, resulting in counter comparisons being inaccurate. This leads to problems with zero threshold detection in XFS.
To fix, add __percpu_counter_compare() to take a caller supplied batch size. This fixes the XFS regression introduced in 4.1-rc1.
-Dave.
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