[PATCH v2 13/21] nfsd: use test_and_clear_bit for somebody_reclaimed to prevent lost update
Jeff Layton <[email protected]>
| Newsgroups | gmane.linux.nfs,gmane.linux.kernel |
|---|---|
| Message-ID | <[email protected]> |
clients_still_reclaiming() uses separate test_bit() and clear_bit()
calls on NFSD_NET_SOMEBODY_RECLAIMED. A concurrent set_bit() from
the OPEN or LOCK reclaim path arriving between the test and clear
is silently lost, causing the next laundromat tick to end grace
prematurely.
Replace with test_and_clear_bit() to make the read-and-clear atomic.
Fixes: 8c67a210c90c ("nfsd: convert nfsd_net boolean flags to unsigned long flags word")
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Jeff Layton <[email protected]>
---
fs/nfsd/nfs4state.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 17cb3b0ad956..0735a3bafa58 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -6884,9 +6884,8 @@ static bool clients_still_reclaiming(struct nfsd_net *nn)
if (atomic_read(&nn->nr_reclaim_complete) == size)
return false;
}
- if (!test_bit(NFSD_NET_SOMEBODY_RECLAIMED, &nn->flags))
+ if (!test_and_clear_bit(NFSD_NET_SOMEBODY_RECLAIMED, &nn->flags))
return false;
- clear_bit(NFSD_NET_SOMEBODY_RECLAIMED, &nn->flags);
/*
* If we've given them *two* lease times to reclaim, and they're
* still not done, give up:
--
2.54.0