IB/hfi1: Reserve user expected TIDs

[ Upstream commit ecf91551cdd2925ed6d9a9d99074fa5f67b90596 ]

To avoid a race, reserve the number of user expected
TIDs before setup.

Fixes: 7e7a436ecb ("staging/hfi1: Add TID entry program function body")
Signed-off-by: Dean Luick <dean.luick@cornelisnetworks.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Link: https://lore.kernel.org/r/167328547636.1472310.7419712824785353905.stgit@awfm-02.cornelisnetworks.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Dean Luick 2023-01-09 12:31:16 -05:00 committed by Greg Kroah-Hartman
parent d307c75f43
commit f5c918dc4e

View File

@ -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;