utsaslab / WineFS

WineFS (SOSP 21): a huge-page aware file system for persistent memory
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Possible bug in pmfs_increase_btree_height #11

Open paulwedeck opened 11 months ago

paulwedeck commented 11 months ago

Steps to reproduce:

This should lead to the fallocate process getting killed and this error message in the kernel log "BUG: unable to handle kernel NULL pointer dereference at 0000000000000000".

I think the issue is that pmfs_increase_btree_height fails due to lack of memory but returns 0 (no error) anyways. The subsequent allocation attempt tries to read from the inner tree node which is a null block which results in this error.