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 <rpete...@redhat.com>
---
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
