block/amend: refactor qcow2 amend options

[mirror_qemu.git] / block / copy-on-read.c

diff --git a/block/copy-on-read.c b/block/copy-on-read.c
index 6a972088889f0502bfed89e8ec2a4da1440004ab..a6e3c74a687e0a25b9e0be9499346a4784f8aed1 100644 (file)
--- a/block/copy-on-read.c
+++ b/block/copy-on-read.c
@@ -22,55 +22,49 @@
 
 #include "qemu/osdep.h"
 #include "block/block_int.h"
+#include "qemu/module.h"
 
 
 static int cor_open(BlockDriverState *bs, QDict *options, int flags,
                     Error **errp)
 {
-    bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, false,
-                               errp);
+    bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
+                               BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
+                               false, errp);
     if (!bs->file) {
         return -EINVAL;
     }
 
     bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
-                                (BDRV_REQ_FUA &
-                                    bs->file->bs->supported_write_flags);
+        (BDRV_REQ_FUA & bs->file->bs->supported_write_flags);
 
     bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
-                               ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
-                                    bs->file->bs->supported_zero_flags);
+        ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
+            bs->file->bs->supported_zero_flags);
 
     return 0;
 }
 
 
-static void cor_close(BlockDriverState *bs)
-{
-}
-
-
 #define PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \
                           | BLK_PERM_WRITE \
                           | BLK_PERM_RESIZE)
 #define PERM_UNCHANGED (BLK_PERM_ALL & ~PERM_PASSTHROUGH)
 
 static void cor_child_perm(BlockDriverState *bs, BdrvChild *c,
-                           const BdrvChildRole *role,
+                           BdrvChildRole role,
                            BlockReopenQueue *reopen_queue,
                            uint64_t perm, uint64_t shared,
                            uint64_t *nperm, uint64_t *nshared)
 {
-    if (c == NULL) {
-        *nperm = (perm & PERM_PASSTHROUGH) | BLK_PERM_WRITE_UNCHANGED;
-        *nshared = (shared & PERM_PASSTHROUGH) | PERM_UNCHANGED;
-        return;
-    }
+    *nperm = perm & PERM_PASSTHROUGH;
+    *nshared = (shared & PERM_PASSTHROUGH) | PERM_UNCHANGED;
 
-    *nperm = (perm & PERM_PASSTHROUGH) |
-             (c->perm & PERM_UNCHANGED);
-    *nshared = (shared & PERM_PASSTHROUGH) |
-               (c->shared_perm & PERM_UNCHANGED);
+    /* We must not request write permissions for an inactive node, the child
+     * cannot provide it. */
+    if (!(bs->open_flags & BDRV_O_INACTIVE)) {
+        *nperm |= BLK_PERM_WRITE_UNCHANGED;
+    }
 }
 
 
@@ -80,13 +74,6 @@ static int64_t cor_getlength(BlockDriverState *bs)
 }
 
 
-static int cor_truncate(BlockDriverState *bs, int64_t offset,
-                        PreallocMode prealloc, Error **errp)
-{
-    return bdrv_truncate(bs->file, offset, prealloc, errp);
-}
-
-
 static int coroutine_fn cor_co_preadv(BlockDriverState *bs,
                                       uint64_t offset, uint64_t bytes,
                                       QEMUIOVector *qiov, int flags)
@@ -116,7 +103,7 @@ static int coroutine_fn cor_co_pwrite_zeroes(BlockDriverState *bs,
 static int coroutine_fn cor_co_pdiscard(BlockDriverState *bs,
                                         int64_t offset, int bytes)
 {
-    return bdrv_co_pdiscard(bs->file->bs, offset, bytes);
+    return bdrv_co_pdiscard(bs->file, offset, bytes);
 }
 
 
@@ -132,22 +119,13 @@ static void cor_lock_medium(BlockDriverState *bs, bool locked)
 }
 
 
-static bool cor_recurse_is_first_non_filter(BlockDriverState *bs,
-                                            BlockDriverState *candidate)
-{
-    return bdrv_recurse_is_first_non_filter(bs->file->bs, candidate);
-}
-
-
-BlockDriver bdrv_copy_on_read = {
+static BlockDriver bdrv_copy_on_read = {
     .format_name                        = "copy-on-read",
 
     .bdrv_open                          = cor_open,
-    .bdrv_close                         = cor_close,
     .bdrv_child_perm                    = cor_child_perm,
 
     .bdrv_getlength                     = cor_getlength,
-    .bdrv_truncate                      = cor_truncate,
 
     .bdrv_co_preadv                     = cor_co_preadv,
     .bdrv_co_pwritev                    = cor_co_pwritev,
@@ -159,8 +137,6 @@ BlockDriver bdrv_copy_on_read = {
 
     .bdrv_co_block_status               = bdrv_co_block_status_from_file,
 
-    .bdrv_recurse_is_first_non_filter   = cor_recurse_is_first_non_filter,
-
     .has_variable_length                = true,
     .is_filter                          = true,
 };