From 8b9b9223449f21c2a604866ae1b25108f1a37ea2 Mon Sep 17 00:00:00 2001
From: Tom Marshall <tdm.code@gmail.com>
Date: Thu, 14 Nov 2019 19:59:40 +0100
Subject: [PATCH] Handle various open failures better

---
 dm-compress/lbatview.c | 17 ++++++++++-------
 dm-compress/lbd.c      | 39 +++++++++++++++++++++++++--------------
 2 files changed, 35 insertions(+), 21 deletions(-)

diff --git a/dm-compress/lbatview.c b/dm-compress/lbatview.c
index fc64cf7..b9552d1 100644
--- a/dm-compress/lbatview.c
+++ b/dm-compress/lbatview.c
@@ -527,13 +527,16 @@ lbatviewcache_dtr(struct lbatviewcache* lvc)
     kfree(lvc->cache);
     lvc->cache = NULL;
     lvc->cache_len = 0;
-    INIT_LIST_HEAD(&lvc->cache_head);
-    lbatpblkcache_dtr(lvc->lpc);
-    kfree(lvc->lpc);
-    lvc->lpc = NULL;
-    pbatcache_dtr(lvc->pc);
-    kfree(lvc->pc);
-    lvc->pc = NULL;
+    if (lvc->lpc) {
+        lbatpblkcache_dtr(lvc->lpc);
+        kfree(lvc->lpc);
+        lvc->lpc = NULL;
+    }
+    if (lvc->pc) {
+        pbatcache_dtr(lvc->pc);
+        kfree(lvc->pc);
+        lvc->pc = NULL;
+    }
     lvc->params = NULL;
 }
 
diff --git a/dm-compress/lbd.c b/dm-compress/lbd.c
index 98252a2..3891b33 100644
--- a/dm-compress/lbd.c
+++ b/dm-compress/lbd.c
@@ -640,6 +640,10 @@ lbdcache_ctr(struct lbdcache* lc,
     lc->params = &kparams->params;
     lc->sync = sync;
     lc->percpu = alloc_percpu(void*);
+    if (!lc->percpu) {
+        printk(KERN_ERR "%s: Out of memory\n", __func__);
+        return false;
+    }
     for (cpu = 0; cpu < num_online_cpus(); ++cpu) {
         if (!lbdcache_alloc_compress_state(lc->percpu, lc->params, cpu)) {
             return false;
@@ -689,12 +693,16 @@ lbdcache_dtr(struct lbdcache* lc)
     struct lbd* lbd;
     int cpu;
 
-    cancel_delayed_work_sync(&lc->flush_dwork);
-    flush_delayed_work(&lc->flush_dwork);
-    list_for_each_entry(lbd, &lc->flush_head, flush_list) {
-        ret = lbd_flush(lbd);
-        if (ret) {
-            printk(KERN_ERR "%s: lbd_flush failed\n", __func__);
+    if (lc->flush_dwork.work.func) {
+        cancel_delayed_work_sync(&lc->flush_dwork);
+        flush_delayed_work(&lc->flush_dwork);
+    }
+    if (lc->flush_head.next) {
+        list_for_each_entry(lbd, &lc->flush_head, flush_list) {
+            ret = lbd_flush(lbd);
+            if (ret) {
+                printk(KERN_ERR "%s: lbd_flush failed\n", __func__);
+            }
         }
     }
     for (n = 0; n < lc->cache_len; ++n) {
@@ -710,15 +718,18 @@ lbdcache_dtr(struct lbdcache* lc)
     kfree(lc->cache);
     lc->cache = NULL;
     lc->cache_len = 0;
-    INIT_LIST_HEAD(&lc->cache_head);
-    lbatviewcache_dtr(lc->lvc);
-    kfree(lc->lvc);
-    lc->lvc = NULL;
-    for (cpu = 0; cpu < num_online_cpus(); ++cpu) {
-        lbdcache_free_compress_state(lc->percpu, lc->params, cpu);
+    if (lc->lvc) {
+        lbatviewcache_dtr(lc->lvc);
+        kfree(lc->lvc);
+        lc->lvc = NULL;
+    }
+    if (lc->percpu) {
+        for (cpu = 0; cpu < num_online_cpus(); ++cpu) {
+            lbdcache_free_compress_state(lc->percpu, lc->params, cpu);
+        }
+        free_percpu(lc->percpu);
+        lc->percpu = NULL;
     }
-    free_percpu(lc->percpu);
-    lc->percpu = NULL;
     lc->params = NULL;
 }