Details
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Technical task
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Resolution: Fixed
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Minor
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None
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None
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9223372036854775807
Description
PCC uses the layout lock to protect the cache validity. Currently PCC only supports auto attach at the next open. However, the layout lock can be revoked at any time by LRU/manual lock shrinking or lock conflict callback.
For example, the layout lock can be revoked when perform I/Os after open the file. At this time, the cached file will be detached involuntary. The I/O originally directed into PCC will redirect to OSTs after the data restore into OSTs' objects. This cost of this unwilling behavior may be expensive.
To avoid this problem, it is necessary to implement auto attach for PCC even during IOs (not only at the open time).
And auto attach should be enabled by default.