From 7a92deaae613c3b95f0fd02814bb09be7f7a5820 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Wed, 3 Nov 2021 16:15:51 +0100 Subject: [PATCH] gfs2: Fix atomic bug in gfs2_instantiate Replace test_bit() + set_bit() with test_and_set_bit() where we need an atomic operation. Use clear_and_wake_up_bit() instead of open coding it. Signed-off-by: Andreas Gruenbacher --- fs/gfs2/glock.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 19f38aee1b61..258d8aae7c53 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -496,7 +496,7 @@ int gfs2_instantiate(struct gfs2_holder *gh) * Since we unlock the lockref lock, we set a flag to indicate * instantiate is in progress. */ - if (test_bit(GLF_INSTANTIATE_IN_PROG, &gl->gl_flags)) { + if (test_and_set_bit(GLF_INSTANTIATE_IN_PROG, &gl->gl_flags)) { wait_on_bit(&gl->gl_flags, GLF_INSTANTIATE_IN_PROG, TASK_UNINTERRUPTIBLE); /* @@ -509,14 +509,10 @@ int gfs2_instantiate(struct gfs2_holder *gh) goto again; } - set_bit(GLF_INSTANTIATE_IN_PROG, &gl->gl_flags); - ret = glops->go_instantiate(gh); if (!ret) clear_bit(GLF_INSTANTIATE_NEEDED, &gl->gl_flags); - clear_bit(GLF_INSTANTIATE_IN_PROG, &gl->gl_flags); - smp_mb__after_atomic(); - wake_up_bit(&gl->gl_flags, GLF_INSTANTIATE_IN_PROG); + clear_and_wake_up_bit(GLF_INSTANTIATE_IN_PROG, &gl->gl_flags); return ret; }