block: Always set writeback mode in blk_new_open()

All callers of blk_new_open() either don't rely on the WCE bit set after
blk_new_open() because they explicitly set it anyway, or they pass
BDRV_O_CACHE_WB unconditionally.

This patch changes blk_new_open() so that it always enables writeback
mode and asserts that BDRV_O_CACHE_WB is clear. For those callers that
used to pass BDRV_O_CACHE_WB unconditionally, the flag is removed now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>

12 files changed, 20 insertions, 28 deletions

diff --git a/block/block-backend.c b/block/block-backend.c
index e578a2d..048f48e 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -148,6 +148,8 @@ BlockBackend *blk_new_open(const char *filename, const char *reference,
     BlockBackend *blk;
     int ret;
 
+    assert((flags & BDRV_O_CACHE_WB) == 0);
+
     blk = blk_new_with_bs(errp);
     if (!blk) {
         QDECREF(options);
@@ -160,6 +162,8 @@ BlockBackend *blk_new_open(const char *filename, const char *reference,
         return NULL;
     }
 
+    blk_set_enable_write_cache(blk, true);
+
     return blk;
 }
 
diff --git a/block/crypto.c b/block/crypto.c
index 3db0965..be34985 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -121,8 +121,7 @@ static ssize_t block_crypto_init_func(QCryptoBlock *block,
     }
 
     data->blk = blk_new_open(data->filename, NULL, NULL,
-                             BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
-                             errp);
+                             BDRV_O_RDWR | BDRV_O_PROTOCOL, errp);
     if (!data->blk) {
         return -1;
     }
diff --git a/block/parallels.c b/block/parallels.c
index 9bba8b3..324ed43 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -480,8 +480,7 @@ static int parallels_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     file = blk_new_open(filename, NULL, NULL,
-                        BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
-                        &local_err);
+                        BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
     if (file == NULL) {
         error_propagate(errp, local_err);
         return -EIO;
diff --git a/block/qcow.c b/block/qcow.c
index b6c2e6e..60ddb12 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -804,8 +804,7 @@ static int qcow_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     qcow_blk = blk_new_open(filename, NULL, NULL,
-                            BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
-                            &local_err);
+                            BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
     if (qcow_blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;
diff --git a/block/qcow2.c b/block/qcow2.c
index 73c4f6b..056525c 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2168,8 +2168,7 @@ static int qcow2_create2(const char *filename, int64_t total_size,
     }
 
     blk = blk_new_open(filename, NULL, NULL,
-                       BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
-                       &local_err);
+                       BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         return -EIO;
@@ -2233,8 +2232,7 @@ static int qcow2_create2(const char *filename, int64_t total_size,
     options = qdict_new();
     qdict_put(options, "driver", qstring_from_str("qcow2"));
     blk = blk_new_open(filename, NULL, options,
-                       BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH,
-                       &local_err);
+                       BDRV_O_RDWR | BDRV_O_NO_FLUSH, &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;
@@ -2295,8 +2293,7 @@ static int qcow2_create2(const char *filename, int64_t total_size,
     options = qdict_new();
     qdict_put(options, "driver", qstring_from_str("qcow2"));
     blk = blk_new_open(filename, NULL, options,
-                       BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_BACKING,
-                       &local_err);
+                       BDRV_O_RDWR | BDRV_O_NO_BACKING, &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;
diff --git a/block/qed.c b/block/qed.c
index c1cc625..0af5274 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -576,8 +576,7 @@ static int qed_create(const char *filename, uint32_t cluster_size,
     }
 
     blk = blk_new_open(filename, NULL, NULL,
-                       BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
-                       &local_err);
+                       BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         return -EIO;
diff --git a/block/sheepdog.c b/block/sheepdog.c
index 48fc165..33e0a33 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -1648,8 +1648,7 @@ static int sd_prealloc(const char *filename, Error **errp)
     int ret;
 
     blk = blk_new_open(filename, NULL, NULL,
-                       BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
-                       errp);
+                       BDRV_O_RDWR | BDRV_O_PROTOCOL, errp);
     if (blk == NULL) {
         ret = -EIO;
         goto out_with_err_set;
@@ -1845,7 +1844,7 @@ static int sd_create(const char *filename, QemuOpts *opts,
         }
 
         blk = blk_new_open(backing_file, NULL, NULL,
-                           BDRV_O_PROTOCOL | BDRV_O_CACHE_WB, errp);
+                           BDRV_O_PROTOCOL, errp);
         if (blk == NULL) {
             ret = -EIO;
             goto out;
diff --git a/block/vdi.c b/block/vdi.c
index 71f417c..75d4819 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -770,8 +770,7 @@ static int vdi_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     blk = blk_new_open(filename, NULL, NULL,
-                       BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
-                       &local_err);
+                       BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;
diff --git a/block/vhdx.c b/block/vhdx.c
index 59426d6..2b7b332 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -1840,8 +1840,7 @@ static int vhdx_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     blk = blk_new_open(filename, NULL, NULL,
-                       BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
-                       &local_err);
+                       BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;
diff --git a/block/vmdk.c b/block/vmdk.c
index a1a9371..45f9d3c 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1663,8 +1663,7 @@ static int vmdk_create_extent(const char *filename, int64_t filesize,
     }
 
     blk = blk_new_open(filename, NULL, NULL,
-                       BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
-                       &local_err);
+                       BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;
@@ -1948,7 +1947,7 @@ static int vmdk_create(const char *filename, QemuOpts *opts, Error **errp)
         }
 
         blk = blk_new_open(full_backing, NULL, NULL,
-                           BDRV_O_NO_BACKING | BDRV_O_CACHE_WB, errp);
+                           BDRV_O_NO_BACKING, errp);
         g_free(full_backing);
         if (blk == NULL) {
             ret = -EIO;
@@ -2020,8 +2019,7 @@ static int vmdk_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     new_blk = blk_new_open(filename, NULL, NULL,
-                           BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
-                           &local_err);
+                           BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
     if (new_blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;
diff --git a/block/vpc.c b/block/vpc.c
index 912dfc1..8830b5b 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -890,8 +890,7 @@ static int vpc_create(const char *filename, QemuOpts *opts, Error **errp)
     }
 
     blk = blk_new_open(filename, NULL, NULL,
-                       BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL,
-                       &local_err);
+                       BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
     if (blk == NULL) {
         error_propagate(errp, local_err);
         ret = -EIO;
diff --git a/blockdev.c b/blockdev.c
index b658913..00a77dc 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -598,6 +598,7 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
         qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_WB, writethrough ? "off" : "on");
         qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_DIRECT, "off");
         qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_NO_FLUSH, "off");
+        assert((bdrv_flags & BDRV_O_CACHE_MASK) == 0);
 
         if (runstate_check(RUN_STATE_INMIGRATE)) {
             bdrv_flags |= BDRV_O_INACTIVE;