From Sachin Punadikar <psachin(a)in.ibm.com&gt;: Sachin Punadikar has uploaded this change for review. ( https://review.gerrithub.io/412321 Change subject: Avoid ABBA kind deadlock while IP release in grace period ...................................................................... Avoid ABBA kind deadlock while IP release in grace period During IP release event ABBA deadlock situation ariases as below. In case of IP release event, nfs4_start_grace (grace_mutex already locked) calls nfs_release_v4_client. In this it gets the list of confirmed client records associated with that IP. It travels that list and attempts to grab lock on client_record->cr_mutex. Now in parallel, there was a new client approaching Ganesha for the IP to be released. As part of response to SETCLIENTID_CONFIRM, nfs4_op_setclientid_confirm, gets the unconfirmed client record, locks it (client_record->cr_mutex) and after validations, makes it part of confirmed clients. As next processing it calls nfs4_chk_clid which needs lock on grace_mutex. As grace_mutex is for protecting clid_list, the locking can be done when it is required. This solves this deadlock issue. Change-Id: Ibdaab87c91b9c78e1b30aa38909032eb7c41f5b6 Signed-off-by: Sachin Punadikar <psachin(a)in.ibm.com&gt; --- M src/SAL/nfs4_recovery.c 1 file changed, 5 insertions(+), 7 deletions(-) git pull ssh://review.gerrithub.io:29418/ffilz/nfs-ganesha refs/changes/21/412321/1 -- To view, visit https://review.gerrithub.io/412321 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: Ibdaab87c91b9c78e1b30aa38909032eb7c41f5b6 Gerrit-Change-Number: 412321 Gerrit-PatchSet: 1 Gerrit-Owner: Sachin Punadikar <psachin(a)in.ibm.com&gt;