Details
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Bug
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Resolution: Fixed
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Critical
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Lustre 2.7.0, Lustre 2.8.0
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None
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3
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9223372036854775807
Description
During lfsck test, I found that sometime the new created directory object's nlink attr is 3, not the expected 2. The root reason is related with the operations order between ref_add(dir) and ea_insert(..). We need three main operations for the new created directory object:
1) insert dot entry
2) insert dotdot entry
3) ref_add on the directory object.
Sometimes, the 3rd step maybe ahead of 1st, sometimes maybe between 1st and 2nd. Usually, the developers would thought that such order is not important. But in fact, such assumption is not true. That is because the ldiskfs will set the new created directory object's nlink as 2. Then if the callers call ref_add() after that, the directory object's nlink attr will become 3.