Commit 20265d9a authored by Bob Peterson's avatar Bob Peterson Committed by Andreas Gruenbacher
Browse files

gfs2: fix scheduling while atomic bug in glocks 



Before this patch, in the unlikely event that gfs2_glock_dq encountered
a withdraw, it would do a wait_on_bit to wait for its journal to be
recovered, but it never released the glock's spin_lock, which caused a
scheduling-while-atomic error.

This patch unlocks the lockref spin_lock before waiting for recovery.

Fixes: 601ef0d5 ("gfs2: Force withdraw to replay journals and wait for it to finish")
Cc: stable@vger.kernel.org # v5.7+
Reported-by: default avatarAlexander Aring <aahringo@redhat.com>
Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
parent 4194dec4

fs/gfs2/glock.c

+2 −0
Original line number Diff line number Diff line
@@ -1466,9 +1466,11 @@ void gfs2_glock_dq(struct gfs2_holder *gh) 
	    glock_blocked_by_withdraw(gl) &&

	    gh->gh_gl != sdp->sd_jinode_gl) {

		sdp->sd_glock_dqs_held++;

		spin_unlock(&gl->gl_lockref.lock);

		might_sleep();

		wait_on_bit(&sdp->sd_flags, SDF_WITHDRAW_RECOVERY,

			    TASK_UNINTERRUPTIBLE);

		spin_lock(&gl->gl_lockref.lock);

	}

	if (gh->gh_flags & GL_NOCACHE)

		handle_callback(gl, LM_ST_UNLOCKED, 0, false);