Implement a proper rw_tryupgrade

[mirror_spl.git] / module / splat / splat-rwlock.c

diff --git a/module/splat/splat-rwlock.c b/module/splat/splat-rwlock.c
index abd6a0e6018f12574b0d03d34e2533b1a16b3bc3..c17eb07ba5c0ba62b499d16cc8ce54744d9b7620 100644 (file)
--- a/module/splat/splat-rwlock.c
+++ b/module/splat/splat-rwlock.c
@@ -55,8 +55,12 @@
 #define SPLAT_RWLOCK_TEST5_DESC                "Write downgrade"
 
 #define SPLAT_RWLOCK_TEST6_ID          0x0706
-#define SPLAT_RWLOCK_TEST6_NAME                "rw_tryupgrade"
-#define SPLAT_RWLOCK_TEST6_DESC                "Read upgrade"
+#define SPLAT_RWLOCK_TEST6_NAME                "rw_tryupgrade-1"
+#define SPLAT_RWLOCK_TEST6_DESC                "rwsem->count value"
+
+#define SPLAT_RWLOCK_TEST7_ID          0x0707
+#define SPLAT_RWLOCK_TEST7_NAME                "rw_tryupgrade-2"
+#define SPLAT_RWLOCK_TEST7_DESC                "Read upgrade"
 
 #define SPLAT_RWLOCK_TEST_MAGIC                0x115599DDUL
 #define SPLAT_RWLOCK_TEST_NAME         "rwlock_test"
@@ -580,8 +584,55 @@ splat_rwlock_test6(struct file *file, void *arg)
        splat_init_rw_priv(rwp, file);
 
        rw_enter(&rwp->rw_rwlock, RW_READER);
-       if (!RW_READ_HELD(&rwp->rw_rwlock)) {
+       if (RWSEM_COUNT(SEM(&rwp->rw_rwlock)) !=
+           SPL_RWSEM_SINGLE_READER_VALUE) {
+               splat_vprint(file, SPLAT_RWLOCK_TEST6_NAME,
+                            "We assumed single reader rwsem->count "
+                            "should be %ld, but is %ld\n",
+                            SPL_RWSEM_SINGLE_READER_VALUE,
+                            RWSEM_COUNT(SEM(&rwp->rw_rwlock)));
+               rc = -ENOLCK;
+               goto out;
+       }
+       rw_exit(&rwp->rw_rwlock);
+
+       rw_enter(&rwp->rw_rwlock, RW_WRITER);
+       if (RWSEM_COUNT(SEM(&rwp->rw_rwlock)) !=
+           SPL_RWSEM_SINGLE_WRITER_VALUE) {
                splat_vprint(file, SPLAT_RWLOCK_TEST6_NAME,
+                            "We assumed single writer rwsem->count "
+                            "should be %ld, but is %ld\n",
+                            SPL_RWSEM_SINGLE_WRITER_VALUE,
+                            RWSEM_COUNT(SEM(&rwp->rw_rwlock)));
+               rc = -ENOLCK;
+               goto out;
+       }
+       rc = 0;
+       splat_vprint(file, SPLAT_RWLOCK_TEST6_NAME, "%s",
+                    "rwsem->count same as we assumed\n");
+out:
+       rw_exit(&rwp->rw_rwlock);
+       rw_destroy(&rwp->rw_rwlock);
+       kfree(rwp);
+
+       return rc;
+}
+
+static int
+splat_rwlock_test7(struct file *file, void *arg)
+{
+       rw_priv_t *rwp;
+       int rc;
+
+       rwp = (rw_priv_t *)kmalloc(sizeof(*rwp), GFP_KERNEL);
+       if (rwp == NULL)
+               return -ENOMEM;
+
+       splat_init_rw_priv(rwp, file);
+
+       rw_enter(&rwp->rw_rwlock, RW_READER);
+       if (!RW_READ_HELD(&rwp->rw_rwlock)) {
+               splat_vprint(file, SPLAT_RWLOCK_TEST7_NAME,
                             "rwlock should be read lock: %d\n",
                             RW_READ_HELD(&rwp->rw_rwlock));
                rc = -ENOLCK;
@@ -591,7 +642,7 @@ splat_rwlock_test6(struct file *file, void *arg)
        /* With one reader upgrade should never fail. */
        rc = rw_tryupgrade(&rwp->rw_rwlock);
        if (!rc) {
-               splat_vprint(file, SPLAT_RWLOCK_TEST6_NAME,
+               splat_vprint(file, SPLAT_RWLOCK_TEST7_NAME,
                             "rwlock failed upgrade from reader: %d\n",
                             RW_READ_HELD(&rwp->rw_rwlock));
                rc = -ENOLCK;
@@ -599,7 +650,7 @@ splat_rwlock_test6(struct file *file, void *arg)
        }
 
        if (RW_READ_HELD(&rwp->rw_rwlock) || !RW_WRITE_HELD(&rwp->rw_rwlock)) {
-               splat_vprint(file, SPLAT_RWLOCK_TEST6_NAME, "rwlock should "
+               splat_vprint(file, SPLAT_RWLOCK_TEST7_NAME, "rwlock should "
                           "have 0 (not %d) reader and 1 (not %d) writer\n",
                           RW_READ_HELD(&rwp->rw_rwlock),
                           RW_WRITE_HELD(&rwp->rw_rwlock));
@@ -607,7 +658,7 @@ splat_rwlock_test6(struct file *file, void *arg)
        }
 
        rc = 0;
-       splat_vprint(file, SPLAT_RWLOCK_TEST6_NAME, "%s",
+       splat_vprint(file, SPLAT_RWLOCK_TEST7_NAME, "%s",
                     "rwlock properly upgraded\n");
 out:
        rw_exit(&rwp->rw_rwlock);
@@ -646,6 +697,8 @@ splat_rwlock_init(void)
                      SPLAT_RWLOCK_TEST5_ID, splat_rwlock_test5);
        SPLAT_TEST_INIT(sub, SPLAT_RWLOCK_TEST6_NAME, SPLAT_RWLOCK_TEST6_DESC,
                      SPLAT_RWLOCK_TEST6_ID, splat_rwlock_test6);
+       SPLAT_TEST_INIT(sub, SPLAT_RWLOCK_TEST7_NAME, SPLAT_RWLOCK_TEST7_DESC,
+                     SPLAT_RWLOCK_TEST7_ID, splat_rwlock_test7);
 
        return sub;
 }
@@ -654,6 +707,7 @@ void
 splat_rwlock_fini(splat_subsystem_t *sub)
 {
        ASSERT(sub);
+       SPLAT_TEST_FINI(sub, SPLAT_RWLOCK_TEST7_ID);
        SPLAT_TEST_FINI(sub, SPLAT_RWLOCK_TEST6_ID);
        SPLAT_TEST_FINI(sub, SPLAT_RWLOCK_TEST5_ID);
        SPLAT_TEST_FINI(sub, SPLAT_RWLOCK_TEST4_ID);