diff options
| -rw-r--r-- | fs/smb/common/smbdirect/smbdirect_connection.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/fs/smb/common/smbdirect/smbdirect_connection.c b/fs/smb/common/smbdirect/smbdirect_connection.c index 81b42eaec8b1..2e90f6a1fcf4 100644 --- a/fs/smb/common/smbdirect/smbdirect_connection.c +++ b/fs/smb/common/smbdirect/smbdirect_connection.c @@ -694,6 +694,100 @@ static int smbdirect_connection_post_recv_io(struct smbdirect_recv_io *msg) return ret; } +__maybe_unused /* this is temporary while this file is included in others */ +static void smbdirect_connection_recv_io_refill_work(struct work_struct *work) +{ + struct smbdirect_socket *sc = + container_of(work, struct smbdirect_socket, recv_io.posted.refill_work); + int missing; + int posted = 0; + + if (unlikely(sc->first_error)) + return; + + /* + * Find out how much smbdirect_recv_io buffers we should post. + * + * Note that sc->recv_io.credits.target is the value + * from the peer and it can in theory change over time, + * but it is forced to be at least 1 and at max + * sp->recv_credit_max. + * + * So it can happen that missing will be lower than 0, + * which means the peer has recently lowered its desired + * target, while be already granted a higher number of credits. + * + * Note 'posted' is the number of smbdirect_recv_io buffers + * posted within this function, while sc->recv_io.posted.count + * is the overall value of posted smbdirect_recv_io buffers. + * + * We try to post as much buffers as missing, but + * this is limited if a lot of smbdirect_recv_io buffers + * are still in the sc->recv_io.reassembly.list instead of + * the sc->recv_io.free.list. + * + */ + missing = (int)sc->recv_io.credits.target - atomic_read(&sc->recv_io.posted.count); + while (posted < missing) { + struct smbdirect_recv_io *recv_io; + int ret; + + /* + * It's ok if smbdirect_connection_get_recv_io() + * returns NULL, it means smbdirect_recv_io structures + * are still be in the reassembly.list. + */ + recv_io = smbdirect_connection_get_recv_io(sc); + if (!recv_io) + break; + + recv_io->first_segment = false; + + ret = smbdirect_connection_post_recv_io(recv_io); + if (ret) { + smbdirect_log_rdma_recv(sc, SMBDIRECT_LOG_ERR, + "smbdirect_connection_post_recv_io failed rc=%d (%1pe)\n", + ret, SMBDIRECT_DEBUG_ERR_PTR(ret)); + smbdirect_connection_put_recv_io(recv_io); + return; + } + + atomic_inc(&sc->recv_io.posted.count); + posted += 1; + } + + /* If nothing was posted we're done */ + if (posted == 0) + return; + + atomic_add(posted, &sc->recv_io.credits.available); + + /* + * If we posted at least one smbdirect_recv_io buffer, + * we need to inform the peer about it and grant + * additional credits. + * + * However there is one case where we don't want to + * do that. + * + * If only a single credit was missing before + * reaching the requested target, we should not + * post an immediate send, as that would cause + * endless ping pong once a keep alive exchange + * is started. + * + * However if sc->recv_io.credits.target is only 1, + * the peer has no credit left and we need to + * grant the credit anyway. + */ + if (missing == 1 && sc->recv_io.credits.target != 1) + return; + + smbdirect_log_keep_alive(sc, SMBDIRECT_LOG_INFO, + "schedule send of an empty message\n"); + queue_work(sc->workqueue, &sc->idle.immediate_work); +} + static bool smbdirect_map_sges_single_page(struct smbdirect_map_sges *state, struct page *page, size_t off, size_t len) { |