From 55c530a7b039866d44d08d5c4844132c85f4a84c Mon Sep 17 00:00:00 2001 From: Dean Luick Date: Mon, 9 Jan 2023 12:31:16 -0500 Subject: [PATCH] IB/hfi1: Reserve user expected TIDs [ Upstream commit ecf91551cdd2925ed6d9a9d99074fa5f67b90596 ] To avoid a race, reserve the number of user expected TIDs before setup. Fixes: 032fa89ceb9c ("staging/hfi1: Add TID entry program function body") Signed-off-by: Dean Luick Signed-off-by: Dennis Dalessandro Link: https://lore.kernel.org/r/167328547636.1472310.7419712824785353905.stgit@awfm-02.cornelisnetworks.com Signed-off-by: Leon Romanovsky Signed-off-by: Sasha Levin --- drivers/infiniband/hw/hfi1/user_exp_rcv.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/user_exp_rcv.c b/drivers/infiniband/hw/hfi1/user_exp_rcv.c index 28f1b3c37a4f0..7623cb61ec4c2 100644 --- a/drivers/infiniband/hw/hfi1/user_exp_rcv.c +++ b/drivers/infiniband/hw/hfi1/user_exp_rcv.c @@ -351,16 +351,13 @@ int hfi1_user_exp_rcv_setup(struct hfi1_filedata *fd, /* Find sets of physically contiguous pages */ tidbuf->n_psets = find_phys_blocks(tidbuf, pinned); - /* - * We don't need to access this under a lock since tid_used is per - * process and the same process cannot be in hfi1_user_exp_rcv_clear() - * and hfi1_user_exp_rcv_setup() at the same time. - */ + /* Reserve the number of expected tids to be used. */ spin_lock(&fd->tid_lock); if (fd->tid_used + tidbuf->n_psets > fd->tid_limit) pageset_count = fd->tid_limit - fd->tid_used; else pageset_count = tidbuf->n_psets; + fd->tid_used += pageset_count; spin_unlock(&fd->tid_lock); if (!pageset_count) @@ -469,10 +466,11 @@ unlock: nomem: hfi1_cdbg(TID, "total mapped: tidpairs:%u pages:%u (%d)", tididx, mapped_pages, ret); + /* adjust reserved tid_used to actual count */ + spin_lock(&fd->tid_lock); + fd->tid_used -= pageset_count - tididx; + spin_unlock(&fd->tid_lock); if (tididx) { - spin_lock(&fd->tid_lock); - fd->tid_used += tididx; - spin_unlock(&fd->tid_lock); tinfo->tidcnt = tididx; tinfo->length = mapped_pages * PAGE_SIZE; -- 2.39.5