path: root/fs/locks.c
diff options
authorJ. Bruce Fields <bfields@redhat.com>2017-07-28 16:35:15 -0400
committerJ. Bruce Fields <bfields@redhat.com>2020-05-08 21:23:10 -0400
commit28df3d1539de5090f7916f6fff03891b67f366f4 (patch)
tree0a324005caeca12e5bb02384d7e30ddc655d9862 /fs/locks.c
parentkthread: save thread function (diff)
nfsd: clients don't need to break their own delegations
We currently revoke read delegations on any write open or any operation that modifies file data or metadata (including rename, link, and unlink). But if the delegation in question is the only read delegation and is held by the client performing the operation, that's not really necessary. It's not always possible to prevent this in the NFSv4.0 case, because there's not always a way to determine which client an NFSv4.0 delegation came from. (In theory we could try to guess this from the transport layer, e.g., by assuming all traffic on a given TCP connection comes from the same client. But that's not really correct.) In the NFSv4.1 case the session layer always tells us the client. This patch should remove such self-conflicts in all cases where we can reliably determine the client from the compound. To do that we need to track "who" is performing a given (possibly lease-breaking) file operation. We're doing that by storing the information in the svc_rqst and using kthread_data() to map the current task back to a svc_rqst. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs/locks.c')
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/locks.c b/fs/locks.c
index b8a31c1c4fff..a3f186846e93 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1557,6 +1557,9 @@ static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker)
bool rc;
+ if (lease->fl_lmops->lm_breaker_owns_lease
+ && lease->fl_lmops->lm_breaker_owns_lease(lease))
+ return false;
if ((breaker->fl_flags & FL_LAYOUT) != (lease->fl_flags & FL_LAYOUT)) {
rc = false;
goto trace;