[Qemu-devel] [PATCH V11 7/8] blkdebug: add debug events for snapshot

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

Some code in qcow2-snapshot.c directly accesses bs->file, so in those
places errors can't be injected by other events. Since the code in
qcow2-snapshot.c is similar to the other qcow2 internal code (in regards
to e.g. the L1 table), add some debug events.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 block/blkdebug.c       |    4 ++++
 block/qcow2-snapshot.c |    3 +++
 include/block/block.h  |    4 ++++
 3 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/block/blkdebug.c b/block/blkdebug.c
index 56c4cd0..6a94dfd 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -194,6 +194,10 @@ static const char *event_names[BLKDBG_EVENT_MAX] = {
     [BLKDBG_PWRITEV]                        = "pwritev",
     [BLKDBG_PWRITEV_ZERO]                   = "pwritev_zero",
     [BLKDBG_PWRITEV_DONE]                   = "pwritev_done",
+
+    [BLKDBG_SNAPSHOT_L1_UPDATE]             = "snapshot_l1_update",
+    [BLKDBG_SNAPSHOT_LIST_UPDATE]           = "snapshot_list_update",
+    [BLKDBG_SNAPSHOT_HEADER_UPDATE]         = "snapshot_header_update",
 };
 
 static int get_event_by_name(const char *name, BlkDebugEvent *event)
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index 12938a0..4746f80 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -209,6 +209,7 @@ static int qcow2_write_snapshots(BlockDriverState *bs,
     }
 
 
+    BLKDBG_EVENT(bs->file, BLKDBG_SNAPSHOT_LIST_UPDATE);
     /* Write all snapshots to the new list */
     for(i = 0; i < s->nb_snapshots; i++) {
         sn = s->snapshots + i;
@@ -305,6 +306,7 @@ static int qcow2_write_snapshots(BlockDriverState *bs,
     header_data.nb_snapshots        = cpu_to_be32(s->nb_snapshots);
     header_data.snapshots_offset    = cpu_to_be64(snapshots_offset);
 
+    BLKDBG_EVENT(bs->file, BLKDBG_SNAPSHOT_HEADER_UPDATE);
     ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, nb_snapshots),
                            &header_data, sizeof(header_data));
     if (ret < 0) {
@@ -475,6 +477,7 @@ void qcow2_snapshot_create(BlockDriverState *bs,
         goto dealloc_l1_table;
     }
 
+    BLKDBG_EVENT(bs->file, BLKDBG_SNAPSHOT_L1_UPDATE);
     ret = bdrv_pwrite(bs->file, sn->l1_table_offset, l1_table,
                       s->l1_size * sizeof(uint64_t));
     if (ret < 0) {
diff --git a/include/block/block.h b/include/block/block.h
index 963a61f..25bcdad 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -535,6 +535,10 @@ typedef enum {
     BLKDBG_PWRITEV_ZERO,
     BLKDBG_PWRITEV_DONE,
 
+    BLKDBG_SNAPSHOT_L1_UPDATE,
+    BLKDBG_SNAPSHOT_LIST_UPDATE,
+    BLKDBG_SNAPSHOT_HEADER_UPDATE,
+
     BLKDBG_EVENT_MAX,
 } BlkDebugEvent;
 
-- 
1.7.1