qcow2: Add qcow2_check_fix_snapshot_table()

qcow2_check_read_snapshot_table() can perform consistency checks, but it
cannot fix everything.  Specifically, it cannot allocate new clusters,
because that should wait until the refcount structures are known to be
consistent (i.e., after qcow2_check_refcounts()).  Thus, it cannot call
qcow2_write_snapshots().

Do that in qcow2_check_fix_snapshot_table(), which is called after
qcow2_check_refcounts().

Currently, there is nothing that would set result->corruptions, so this
is a no-op.  A follow-up patch will change that.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20191011152814.14791-10-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>

diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index d667bfd93543da1e65cc1c8d6be91c26c080f190..b526a8f8191bb8b81b54a522412477924aece6c4 100644 (file)
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -380,6 +380,31 @@ int coroutine_fn qcow2_check_read_snapshot_table(BlockDriverState *bs,
     return 0;
 }
 
+int coroutine_fn qcow2_check_fix_snapshot_table(BlockDriverState *bs,
+                                                BdrvCheckResult *result,
+                                                BdrvCheckMode fix)
+{
+    BDRVQcow2State *s = bs->opaque;
+    int ret;
+
+    if (result->corruptions && (fix & BDRV_FIX_ERRORS)) {
+        qemu_co_mutex_unlock(&s->lock);
+        ret = qcow2_write_snapshots(bs);
+        qemu_co_mutex_lock(&s->lock);
+        if (ret < 0) {
+            result->check_errors++;
+            fprintf(stderr, "ERROR failed to update snapshot table: %s\n",
+                    strerror(-ret));
+            return ret;
+        }
+
+        result->corruptions_fixed += result->corruptions;
+        result->corruptions = 0;
+    }
+
+    return 0;
+}
+
 static void find_new_snapshot_id(BlockDriverState *bs,
                                  char *id_str, int id_str_size)
 {

diff --git a/block/qcow2.c b/block/qcow2.c
index b0026e8a9a200bcbe9234001df70bba05c4acdf5..8d4f38ae744e63eee390730e7467e913dc608951 100644 (file)
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -597,13 +597,20 @@ static int coroutine_fn qcow2_co_check_locked(BlockDriverState *bs,
     memset(result, 0, sizeof(*result));
 
     ret = qcow2_check_read_snapshot_table(bs, &snapshot_res, fix);
-    qcow2_add_check_result(result, &snapshot_res, false);
     if (ret < 0) {
+        qcow2_add_check_result(result, &snapshot_res, false);
         return ret;
     }
 
     ret = qcow2_check_refcounts(bs, &refcount_res, fix);
     qcow2_add_check_result(result, &refcount_res, true);
+    if (ret < 0) {
+        qcow2_add_check_result(result, &snapshot_res, false);
+        return ret;
+    }
+
+    ret = qcow2_check_fix_snapshot_table(bs, &snapshot_res, fix);
+    qcow2_add_check_result(result, &snapshot_res, false);
     if (ret < 0) {
         return ret;
     }

diff --git a/block/qcow2.h b/block/qcow2.h
index adb5c3bc28e2ef1d32936123c1aafc634ba8a5ca..601c2e4c8257c2a1f4867b3e2d8c451586ac832a 100644 (file)
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -721,6 +721,9 @@ int qcow2_write_snapshots(BlockDriverState *bs);
 int coroutine_fn qcow2_check_read_snapshot_table(BlockDriverState *bs,
                                                  BdrvCheckResult *result,
                                                  BdrvCheckMode fix);
+int coroutine_fn qcow2_check_fix_snapshot_table(BlockDriverState *bs,
+                                                BdrvCheckResult *result,
+                                                BdrvCheckMode fix);
 
 /* qcow2-cache.c functions */
 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,