Hi Ben, On 11/18/2016 05:03 AM, Benjamin Coddington wrote:
While walking the list of lock_states, keep a reference on each nfs4_lock_state to be checked, otherwise the lock state could be removed while the check performs TEST_STATEID and possible FREE_STATEID. Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx> --- fs/nfs/nfs4proc.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 7897826d7c51..57d102d0f075 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2564,15 +2564,23 @@ static void nfs41_check_delegation_stateid(struct nfs4_state *state) static int nfs41_check_expired_locks(struct nfs4_state *state) { int status, ret = NFS_OK; - struct nfs4_lock_state *lsp; + struct nfs4_lock_state *lsp, *prev = NULL; struct nfs_server *server = NFS_SERVER(state->inode); if (!test_bit(LK_STATE_IN_USE, &state->flags)) goto out; + + spin_lock(&state->state_lock); list_for_each_entry(lsp, &state->lock_states, ls_locks) { if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) { struct rpc_cred *cred = lsp->ls_state->owner->so_cred; + atomic_inc(&lsp->ls_count); + spin_unlock(&state->state_lock); + + nfs4_put_lock_state(prev); + prev = lsp; + status = nfs41_test_and_free_expired_stateid(server, &lsp->ls_stateid, cred); @@ -2587,8 +2595,11 @@ static int nfs41_check_expired_locks(struct nfs4_state *state) ret = status; break;
Should this "break" be replaced with a "goto out" since we're no longer holding the lock at this point? Thanks, Anna
} + spin_lock(&state->state_lock); } - }; + } + spin_unlock(&state->state_lock); + nfs4_put_lock_state(prev); out: return ret; }
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