From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bob Peterson Date: Thu, 16 Sep 2021 14:10:02 -0500 Subject: [Cluster-devel] [GFS2 PATCH v2 5/6] gfs2: simplify do_promote and fix promote trace In-Reply-To: <20210916191003.105866-1-rpeterso@redhat.com> References: <20210916191003.105866-1-rpeterso@redhat.com> Message-ID: <20210916191003.105866-6-rpeterso@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Before this patch, the gfs2_promote kernel trace point would would only record the "first" flag if the go_lock function was called. This patch simplifies do_promote by eliminating the redundant code in do_promote and fixes the trace point by adding a new gfs2_first_holder function. This will also be used in a future patch. Signed-off-by: Bob Peterson --- fs/gfs2/glock.c | 19 ++++++++++++------- fs/gfs2/glock.h | 7 +++++++ 2 files changed, 19 insertions(+), 7 deletions(-) diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index b8248ceff3c3..4fcf340603e7 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -394,6 +394,7 @@ __acquires(&gl->gl_lockref.lock) { const struct gfs2_glock_operations *glops = gl->gl_ops; struct gfs2_holder *gh, *tmp; + int first; int ret; restart: @@ -401,8 +402,8 @@ __acquires(&gl->gl_lockref.lock) if (test_bit(HIF_HOLDER, &gh->gh_iflags)) continue; if (may_grant(gl, gh)) { - if (gh->gh_list.prev == &gl->gl_holders && - glops->go_lock) { + first = gfs2_first_holder(gh); + if (first && glops->go_lock) { if (!(gh->gh_flags & GL_SKIP)) { spin_unlock(&gl->gl_lockref.lock); /* FIXME: eliminate this eventually */ @@ -418,14 +419,18 @@ __acquires(&gl->gl_lockref.lock) goto restart; } } - set_bit(HIF_HOLDER, &gh->gh_iflags); - trace_gfs2_promote(gh, 1); - gfs2_holder_wake(gh); - goto restart; } set_bit(HIF_HOLDER, &gh->gh_iflags); - trace_gfs2_promote(gh, 0); + trace_gfs2_promote(gh, first); gfs2_holder_wake(gh); + /* + * If this was the first holder, we may have released + * the gl_lockref.lock, so the holders list may have + * changed. For that reason, we start again at the + * start of the holders queue. + */ + if (first) + goto restart; continue; } if (gh->gh_list.prev == &gl->gl_holders) diff --git a/fs/gfs2/glock.h b/fs/gfs2/glock.h index 31a8f2f649b5..699c5e95006a 100644 --- a/fs/gfs2/glock.h +++ b/fs/gfs2/glock.h @@ -325,6 +325,13 @@ static inline void glock_clear_object(struct gfs2_glock *gl, void *object) spin_unlock(&gl->gl_lockref.lock); } +static inline bool gfs2_first_holder(struct gfs2_holder *gh) +{ + struct gfs2_glock *gl = gh->gh_gl; + + return (gh->gh_list.prev == &gl->gl_holders); +} + extern void gfs2_inode_remember_delete(struct gfs2_glock *gl, u64 generation); extern bool gfs2_inode_already_deleted(struct gfs2_glock *gl, u64 generation); -- 2.31.1