From Daniel Gryniewicz <dang(a)redhat.com&gt;: Daniel Gryniewicz has uploaded this change for review. ( https://review.gerrithub.io/419268 Change subject: MDCACHE - Close more export/unexport races ...................................................................... MDCACHE - Close more export/unexport races When cleaning up the expmap, once it's empty, we try to push the entry to the CLEANUP queue. However, if something (say lru_run_lane()) takes a ref, then we won't push to the CLEANUP queue, and also won't clear first_export_id, leaving it set to the last (and now removed) export. This will cause lru_run_lane() to eventually assert when it gets to that entry. To close this, unconditionally set first_export_id to -1, indicating that the entry is unmapped, and check the first_export_id before getting a ref in lru_run_lane(), so that we can skip the entry without taking a ref, as putting the ref requires an export. The second race is that we call init_export_root() before we call insert_gsh_export(); this means that the root entry, with it's mapped export, is visible to lru_run_lane() before the export can be looked up. To close this race, skip entries with no export, rather than asserting. Change-Id: Iac8dead8864872065a7bad8aeb9f719b865d4636 Signed-off-by: Daniel Gryniewicz <dang(a)redhat.com&gt; --- M src/FSAL/Stackable_FSALs/FSAL_MDCACHE/mdcache_export.c M src/FSAL/Stackable_FSALs/FSAL_MDCACHE/mdcache_lru.c 2 files changed, 28 insertions(+), 22 deletions(-) git pull ssh://review.gerrithub.io:29418/ffilz/nfs-ganesha refs/changes/68/419268/1 -- To view, visit https://review.gerrithub.io/419268 To unsubscribe, or for help writing mail filters, visit https://review.gerrithub.io/settings Gerrit-Project: ffilz/nfs-ganesha Gerrit-Branch: next Gerrit-MessageType: newchange Gerrit-Change-Id: Iac8dead8864872065a7bad8aeb9f719b865d4636 Gerrit-Change-Number: 419268 Gerrit-PatchSet: 1 Gerrit-Owner: Daniel Gryniewicz <dang(a)redhat.com&gt;