Merge tag 'xtensa-20240117' of https://github.com/jcmvbkbc/linux-xtensa

[linux-2.6-block.git] / fs / gfs2 / glock.c

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index d8b619ed2f1e6fd08367d046611b47d703207845..34540f9d011ca6ca46496900fc74428f9a4f632e 100644 (file)
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -156,7 +156,7 @@ static bool glock_blocked_by_withdraw(struct gfs2_glock *gl)
 {
        struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 
-       if (likely(!gfs2_withdrawn(sdp)))
+       if (!gfs2_withdrawing_or_withdrawn(sdp))
                return false;
        if (gl->gl_ops->go_flags & GLOF_NONDISK)
                return false;
@@ -278,7 +278,7 @@ static void __gfs2_glock_put(struct gfs2_glock *gl)
        GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
        if (mapping) {
                truncate_inode_pages_final(mapping);
-               if (!gfs2_withdrawn(sdp))
+               if (!gfs2_withdrawing_or_withdrawn(sdp))
                        GLOCK_BUG_ON(gl, !mapping_empty(mapping));
        }
        trace_gfs2_glock_put(gl);
@@ -516,6 +516,23 @@ static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
        return NULL;
 }
 
+/**
+ * find_last_waiter - find the last gh that's waiting for the glock
+ * @gl: the glock
+ *
+ * This also is a fast way of finding out if there are any waiters.
+ */
+
+static inline struct gfs2_holder *find_last_waiter(const struct gfs2_glock *gl)
+{
+       struct gfs2_holder *gh;
+
+       if (list_empty(&gl->gl_holders))
+               return NULL;
+       gh = list_last_entry(&gl->gl_holders, struct gfs2_holder, gh_list);
+       return test_bit(HIF_HOLDER, &gh->gh_iflags) ? NULL : gh;
+}
+
 /**
  * state_change - record that the glock is now in a different state
  * @gl: the glock
@@ -757,7 +774,7 @@ skip_inval:
         * gfs2_gl_hash_clear calls clear_glock) and recovery is complete
         * then it's okay to tell dlm to unlock it.
         */
-       if (unlikely(sdp->sd_log_error && !gfs2_withdrawn(sdp)))
+       if (unlikely(sdp->sd_log_error) && !gfs2_withdrawing_or_withdrawn(sdp))
                gfs2_withdraw_delayed(sdp);
        if (glock_blocked_by_withdraw(gl) &&
            (target != LM_ST_UNLOCKED ||
@@ -794,7 +811,7 @@ skip_inval:
                        gfs2_glock_queue_work(gl, 0);
                } else if (ret) {
                        fs_err(sdp, "lm_lock ret %d\n", ret);
-                       GLOCK_BUG_ON(gl, !gfs2_withdrawn(sdp));
+                       GLOCK_BUG_ON(gl, !gfs2_withdrawing_or_withdrawn(sdp));
                }
        } else { /* lock_nolock */
                finish_xmote(gl, target);
@@ -1555,11 +1572,30 @@ trap_recursive:
 int gfs2_glock_nq(struct gfs2_holder *gh)
 {
        struct gfs2_glock *gl = gh->gh_gl;
-       int error = 0;
+       int error;
 
        if (glock_blocked_by_withdraw(gl) && !(gh->gh_flags & LM_FLAG_NOEXP))
                return -EIO;
 
+       if (gh->gh_flags & GL_NOBLOCK) {
+               struct gfs2_holder *current_gh;
+
+               error = -ECHILD;
+               spin_lock(&gl->gl_lockref.lock);
+               if (find_last_waiter(gl))
+                       goto unlock;
+               current_gh = find_first_holder(gl);
+               if (!may_grant(gl, current_gh, gh))
+                       goto unlock;
+               set_bit(HIF_HOLDER, &gh->gh_iflags);
+               list_add_tail(&gh->gh_list, &gl->gl_holders);
+               trace_gfs2_promote(gh);
+               error = 0;
+unlock:
+               spin_unlock(&gl->gl_lockref.lock);
+               return error;
+       }
+
        if (test_bit(GLF_LRU, &gl->gl_flags))
                gfs2_glock_remove_from_lru(gl);
 
@@ -1575,6 +1611,7 @@ int gfs2_glock_nq(struct gfs2_holder *gh)
        run_queue(gl, 1);
        spin_unlock(&gl->gl_lockref.lock);
 
+       error = 0;
        if (!(gh->gh_flags & GL_ASYNC))
                error = gfs2_glock_wait(gh);