Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

Block pull request

# gpg: Signature made Thu 13 Mar 2014 13:50:49 GMT using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/block-pull-request: (24 commits)
  block/raw-win32: bdrv_parse_filename() for hdev
  block/raw-posix: Strip protocol prefix on creation
  block/raw-posix: bdrv_parse_filename() for cdrom
  block/raw-posix: bdrv_parse_filename() for floppy
  block/raw-posix: bdrv_parse_filename() for hdev
  qemu-io: Fix warnings from static code analysis
  block: Unlink temporary file
  qcow2: Don't write with BDRV_O_INCOMING
  qcow2: Keep option in qcow2_invalidate_cache()
  qmp: add query-iothreads command
  iothread: stash thread ID away
  dataplane: replace internal thread with IOThread
  iothread: add "iothread" qdev property type
  qdev: make get_pointer() handle temporary strings
  iothread: add I/O thread object
  aio: add aio_context_acquire() and aio_context_release()
  rfifolock: add recursive FIFO lock
  object: add object_get_canonical_path_component()
  block: Rewrite the snapshot authorization mechanism for block filters.
  iotests: Test corruption during COW request
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

5 files changed, 193 insertions, 0 deletions

diff --git a/tests/Makefile b/tests/Makefile
index 7bc3999ecc..471b4c8785 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -35,6 +35,7 @@ check-unit-y += tests/test-visitor-serialization$(EXESUF)
 check-unit-y += tests/test-iov$(EXESUF)
 gcov-files-test-iov-y = util/iov.c
 check-unit-y += tests/test-aio$(EXESUF)
+check-unit-y += tests/test-rfifolock$(EXESUF)
 check-unit-y += tests/test-throttle$(EXESUF)
 gcov-files-test-aio-$(CONFIG_WIN32) = aio-win32.c
 gcov-files-test-aio-$(CONFIG_POSIX) = aio-posix.c
@@ -193,6 +194,7 @@ tests/check-qjson$(EXESUF): tests/check-qjson.o libqemuutil.a libqemustub.a
 tests/check-qom-interface$(EXESUF): tests/check-qom-interface.o $(qom-core-obj) libqemuutil.a libqemustub.a
 tests/test-coroutine$(EXESUF): tests/test-coroutine.o $(block-obj-y) libqemuutil.a libqemustub.a
 tests/test-aio$(EXESUF): tests/test-aio.o $(block-obj-y) libqemuutil.a libqemustub.a
+tests/test-rfifolock$(EXESUF): tests/test-rfifolock.o libqemuutil.a libqemustub.a
 tests/test-throttle$(EXESUF): tests/test-throttle.o $(block-obj-y) libqemuutil.a libqemustub.a
 tests/test-thread-pool$(EXESUF): tests/test-thread-pool.o $(block-obj-y) libqemuutil.a libqemustub.a
 tests/test-iov$(EXESUF): tests/test-iov.o libqemuutil.a
diff --git a/tests/qemu-iotests/060 b/tests/qemu-iotests/060
index af8ed9f39a..f0116aab1d 100755
--- a/tests/qemu-iotests/060
+++ b/tests/qemu-iotests/060
@@ -138,6 +138,32 @@ $QEMU_IMG snapshot -a foo "$TEST_IMG"
 _check_test_img
 $QEMU_IO -c "$OPEN_RO" -c "read -P 1 0 512" | _filter_qemu_io
 
+echo
+echo "=== Testing overlap while COW is in flight ==="
+echo
+# compat=0.10 is required in order to make the following discard actually
+# unallocate the sector rather than make it a zero sector - we want COW, after
+# all.
+IMGOPTS='compat=0.10' _make_test_img 1G
+# Write two clusters, the second one enforces creation of an L2 table after
+# the first data cluster.
+$QEMU_IO -c 'write 0k 64k' -c 'write 512M 64k' "$TEST_IMG" | _filter_qemu_io
+# Discard the first cluster. This cluster will soon enough be reallocated and
+# used for COW.
+$QEMU_IO -c 'discard 0k 64k' "$TEST_IMG" | _filter_qemu_io
+# Now, corrupt the image by marking the second L2 table cluster as free.
+poke_file "$TEST_IMG" '131084' "\x00\x00" # 0x2000c
+# Start a write operation requiring COW on the image stopping it right before
+# doing the read; then, trigger the corruption prevention by writing anything to
+# any unallocated cluster, leading to an attempt to overwrite the second L2
+# table. Finally, resume the COW write and see it fail (but not crash).
+echo "open -o file.driver=blkdebug $TEST_IMG
+break cow_read 0
+aio_write 0k 1k
+wait_break 0
+write 64k 64k
+resume 0" | $QEMU_IO | _filter_qemu_io
+
 # success, all done
 echo "*** done"
 rm -f $seq.full
diff --git a/tests/qemu-iotests/060.out b/tests/qemu-iotests/060.out
index 6c7bdbb2f2..a517948036 100644
--- a/tests/qemu-iotests/060.out
+++ b/tests/qemu-iotests/060.out
@@ -78,4 +78,19 @@ read 512/512 bytes at offset 0
 No errors were found on the image.
 read 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+=== Testing overlap while COW is in flight ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 
+wrote 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 65536/65536 bytes at offset 536870912
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+discard 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+qcow2: Preventing invalid write on metadata (overlaps with active L2 table); image marked as corrupt.
+blkdebug: Suspended request '0'
+write failed: Input/output error
+blkdebug: Resuming request '0'
+aio_write failed: No medium found
 *** done
diff --git a/tests/test-aio.c b/tests/test-aio.c
index 592721ed3f..56f4288ca8 100644
--- a/tests/test-aio.c
+++ b/tests/test-aio.c
@@ -112,6 +112,64 @@ static void test_notify(void)
     g_assert(!aio_poll(ctx, false));
 }
 
+typedef struct {
+    QemuMutex start_lock;
+    bool thread_acquired;
+} AcquireTestData;
+
+static void *test_acquire_thread(void *opaque)
+{
+    AcquireTestData *data = opaque;
+
+    /* Wait for other thread to let us start */
+    qemu_mutex_lock(&data->start_lock);
+    qemu_mutex_unlock(&data->start_lock);
+
+    aio_context_acquire(ctx);
+    aio_context_release(ctx);
+
+    data->thread_acquired = true; /* success, we got here */
+
+    return NULL;
+}
+
+static void dummy_notifier_read(EventNotifier *unused)
+{
+    g_assert(false); /* should never be invoked */
+}
+
+static void test_acquire(void)
+{
+    QemuThread thread;
+    EventNotifier notifier;
+    AcquireTestData data;
+
+    /* Dummy event notifier ensures aio_poll() will block */
+    event_notifier_init(&notifier, false);
+    aio_set_event_notifier(ctx, &notifier, dummy_notifier_read);
+    g_assert(!aio_poll(ctx, false)); /* consume aio_notify() */
+
+    qemu_mutex_init(&data.start_lock);
+    qemu_mutex_lock(&data.start_lock);
+    data.thread_acquired = false;
+
+    qemu_thread_create(&thread, "test_acquire_thread",
+                       test_acquire_thread,
+                       &data, QEMU_THREAD_JOINABLE);
+
+    /* Block in aio_poll(), let other thread kick us and acquire context */
+    aio_context_acquire(ctx);
+    qemu_mutex_unlock(&data.start_lock); /* let the thread run */
+    g_assert(!aio_poll(ctx, true));
+    aio_context_release(ctx);
+
+    qemu_thread_join(&thread);
+    aio_set_event_notifier(ctx, &notifier, NULL);
+    event_notifier_cleanup(&notifier);
+
+    g_assert(data.thread_acquired);
+}
+
 static void test_bh_schedule(void)
 {
     BHTestData data = { .n = 0 };
@@ -775,6 +833,7 @@ int main(int argc, char **argv)
 
     g_test_init(&argc, &argv, NULL);
     g_test_add_func("/aio/notify",                  test_notify);
+    g_test_add_func("/aio/acquire",                 test_acquire);
     g_test_add_func("/aio/bh/schedule",             test_bh_schedule);
     g_test_add_func("/aio/bh/schedule10",           test_bh_schedule10);
     g_test_add_func("/aio/bh/cancel",               test_bh_cancel);
diff --git a/tests/test-rfifolock.c b/tests/test-rfifolock.c
new file mode 100644
index 0000000000..0572ebb42a
--- /dev/null
+++ b/tests/test-rfifolock.c
@@ -0,0 +1,91 @@
+/*
+ * RFifoLock tests
+ *
+ * Copyright Red Hat, Inc. 2013
+ *
+ * Authors:
+ *  Stefan Hajnoczi    <stefanha@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ */
+
+#include <glib.h>
+#include "qemu-common.h"
+#include "qemu/rfifolock.h"
+
+static void test_nesting(void)
+{
+    RFifoLock lock;
+
+    /* Trivial test, ensure the lock is recursive */
+    rfifolock_init(&lock, NULL, NULL);
+    rfifolock_lock(&lock);
+    rfifolock_lock(&lock);
+    rfifolock_lock(&lock);
+    rfifolock_unlock(&lock);
+    rfifolock_unlock(&lock);
+    rfifolock_unlock(&lock);
+    rfifolock_destroy(&lock);
+}
+
+typedef struct {
+    RFifoLock lock;
+    int fd[2];
+} CallbackTestData;
+
+static void rfifolock_cb(void *opaque)
+{
+    CallbackTestData *data = opaque;
+    int ret;
+    char c = 0;
+
+    ret = write(data->fd[1], &c, sizeof(c));
+    g_assert(ret == 1);
+}
+
+static void *callback_thread(void *opaque)
+{
+    CallbackTestData *data = opaque;
+
+    /* The other thread holds the lock so the contention callback will be
+     * invoked...
+     */
+    rfifolock_lock(&data->lock);
+    rfifolock_unlock(&data->lock);
+    return NULL;
+}
+
+static void test_callback(void)
+{
+    CallbackTestData data;
+    QemuThread thread;
+    int ret;
+    char c;
+
+    rfifolock_init(&data.lock, rfifolock_cb, &data);
+    ret = qemu_pipe(data.fd);
+    g_assert(ret == 0);
+
+    /* Hold lock but allow the callback to kick us by writing to the pipe */
+    rfifolock_lock(&data.lock);
+    qemu_thread_create(&thread, "callback_thread",
+                       callback_thread, &data, QEMU_THREAD_JOINABLE);
+    ret = read(data.fd[0], &c, sizeof(c));
+    g_assert(ret == 1);
+    rfifolock_unlock(&data.lock);
+    /* If we got here then the callback was invoked, as expected */
+
+    qemu_thread_join(&thread);
+    close(data.fd[0]);
+    close(data.fd[1]);
+    rfifolock_destroy(&data.lock);
+}
+
+int main(int argc, char **argv)
+{
+    g_test_init(&argc, &argv, NULL);
+    g_test_add_func("/nesting", test_nesting);
+    g_test_add_func("/callback", test_callback);
+    return g_test_run();
+}