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-rw-r--r--fs/gfs2/glock.c97
1 files changed, 65 insertions, 32 deletions
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index ddcdbf4..9adf8f9 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -328,6 +328,30 @@ static void gfs2_holder_wake(struct gfs2_holder *gh)
}
/**
+ * do_error - Something unexpected has happened during a lock request
+ *
+ */
+
+static inline void do_error(struct gfs2_glock *gl, const int ret)
+{
+ struct gfs2_holder *gh, *tmp;
+
+ list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
+ if (test_bit(HIF_HOLDER, &gh->gh_iflags))
+ continue;
+ if (ret & LM_OUT_ERROR)
+ gh->gh_error = -EIO;
+ else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
+ gh->gh_error = GLR_TRYFAILED;
+ else
+ continue;
+ list_del_init(&gh->gh_list);
+ trace_gfs2_glock_queue(gh, 0);
+ gfs2_holder_wake(gh);
+ }
+}
+
+/**
* do_promote - promote as many requests as possible on the current queue
* @gl: The glock
*
@@ -375,36 +399,13 @@ restart:
}
if (gh->gh_list.prev == &gl->gl_holders)
return 1;
+ do_error(gl, 0);
break;
}
return 0;
}
/**
- * do_error - Something unexpected has happened during a lock request
- *
- */
-
-static inline void do_error(struct gfs2_glock *gl, const int ret)
-{
- struct gfs2_holder *gh, *tmp;
-
- list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
- if (test_bit(HIF_HOLDER, &gh->gh_iflags))
- continue;
- if (ret & LM_OUT_ERROR)
- gh->gh_error = -EIO;
- else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
- gh->gh_error = GLR_TRYFAILED;
- else
- continue;
- list_del_init(&gh->gh_list);
- trace_gfs2_glock_queue(gh, 0);
- gfs2_holder_wake(gh);
- }
-}
-
-/**
* find_first_waiter - find the first gh that's waiting for the glock
* @gl: the glock
*/
@@ -1062,6 +1063,9 @@ int gfs2_glock_nq(struct gfs2_holder *gh)
spin_lock(&gl->gl_spin);
add_to_queue(gh);
+ if ((LM_FLAG_NOEXP & gh->gh_flags) &&
+ test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
+ set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
run_queue(gl, 1);
spin_unlock(&gl->gl_spin);
@@ -1319,6 +1323,36 @@ void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
}
/**
+ * gfs2_should_freeze - Figure out if glock should be frozen
+ * @gl: The glock in question
+ *
+ * Glocks are not frozen if (a) the result of the dlm operation is
+ * an error, (b) the locking operation was an unlock operation or
+ * (c) if there is a "noexp" flagged request anywhere in the queue
+ *
+ * Returns: 1 if freezing should occur, 0 otherwise
+ */
+
+static int gfs2_should_freeze(const struct gfs2_glock *gl)
+{
+ const struct gfs2_holder *gh;
+
+ if (gl->gl_reply & ~LM_OUT_ST_MASK)
+ return 0;
+ if (gl->gl_target == LM_ST_UNLOCKED)
+ return 0;
+
+ list_for_each_entry(gh, &gl->gl_holders, gh_list) {
+ if (test_bit(HIF_HOLDER, &gh->gh_iflags))
+ continue;
+ if (LM_FLAG_NOEXP & gh->gh_flags)
+ return 0;
+ }
+
+ return 1;
+}
+
+/**
* gfs2_glock_complete - Callback used by locking
* @gl: Pointer to the glock
* @ret: The return value from the dlm
@@ -1328,18 +1362,17 @@ void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
{
struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
+
gl->gl_reply = ret;
+
if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_flags))) {
- struct gfs2_holder *gh;
spin_lock(&gl->gl_spin);
- gh = find_first_waiter(gl);
- if ((!(gh && (gh->gh_flags & LM_FLAG_NOEXP)) &&
- (gl->gl_target != LM_ST_UNLOCKED)) ||
- ((ret & ~LM_OUT_ST_MASK) != 0))
+ if (gfs2_should_freeze(gl)) {
set_bit(GLF_FROZEN, &gl->gl_flags);
- spin_unlock(&gl->gl_spin);
- if (test_bit(GLF_FROZEN, &gl->gl_flags))
+ spin_unlock(&gl->gl_spin);
return;
+ }
+ spin_unlock(&gl->gl_spin);
}
set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
gfs2_glock_hold(gl);
@@ -1348,7 +1381,7 @@ void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
}
-static int gfs2_shrink_glock_memory(int nr, gfp_t gfp_mask)
+static int gfs2_shrink_glock_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask)
{
struct gfs2_glock *gl;
int may_demote;
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