block: Convert bs->backing_hd to BdrvChild
This is the final step in converting all of the BlockDriverState
pointers that block drivers use to BdrvChild.
After this patch, bs->children contains the full list of child nodes
that are referenced by a given BDS, and these children are only
referenced through BdrvChild, so that updating the pointer in there is
enough for changing edges in the graph.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/block.c b/block.c
index 33ecd93..ecc0885 100644
--- a/block.c
+++ b/block.c
@@ -721,7 +721,7 @@
};
/*
- * Returns the flags that bs->backing_hd should get, based on the given flags
+ * Returns the flags that bs->backing should get, based on the given flags
* for the parent BDS
*/
static int bdrv_backing_flags(int flags)
@@ -1115,32 +1115,31 @@
void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd)
{
- if (bs->backing_hd) {
+ if (bs->backing) {
assert(bs->backing_blocker);
- bdrv_op_unblock_all(bs->backing_hd, bs->backing_blocker);
- bdrv_detach_child(bs->backing_child);
+ bdrv_op_unblock_all(bs->backing->bs, bs->backing_blocker);
+ bdrv_detach_child(bs->backing);
} else if (backing_hd) {
error_setg(&bs->backing_blocker,
"node is used as backing hd of '%s'",
bdrv_get_device_or_node_name(bs));
}
- bs->backing_hd = backing_hd;
if (!backing_hd) {
error_free(bs->backing_blocker);
bs->backing_blocker = NULL;
- bs->backing_child = NULL;
+ bs->backing = NULL;
goto out;
}
- bs->backing_child = bdrv_attach_child(bs, backing_hd, &child_backing);
+ bs->backing = bdrv_attach_child(bs, backing_hd, &child_backing);
bs->open_flags &= ~BDRV_O_NO_BACKING;
pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename);
pstrcpy(bs->backing_format, sizeof(bs->backing_format),
backing_hd->drv ? backing_hd->drv->format_name : "");
- bdrv_op_block_all(bs->backing_hd, bs->backing_blocker);
+ bdrv_op_block_all(backing_hd, bs->backing_blocker);
/* Otherwise we won't be able to commit due to check in bdrv_commit */
- bdrv_op_unblock(bs->backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET,
+ bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET,
bs->backing_blocker);
out:
bdrv_refresh_limits(bs, NULL);
@@ -1161,7 +1160,7 @@
BlockDriverState *backing_hd;
Error *local_err = NULL;
- if (bs->backing_hd != NULL) {
+ if (bs->backing != NULL) {
QDECREF(options);
goto free_exit;
}
@@ -1201,7 +1200,7 @@
qdict_put(options, "driver", qstring_from_str(bs->backing_format));
}
- assert(bs->backing_hd == NULL);
+ assert(bs->backing == NULL);
ret = bdrv_open_inherit(&backing_hd,
*backing_filename ? backing_filename : NULL,
NULL, options, 0, bs, &child_backing, &local_err);
@@ -1892,8 +1891,8 @@
bs->drv->bdrv_close(bs);
bs->drv = NULL;
- if (bs->backing_hd) {
- BlockDriverState *backing_hd = bs->backing_hd;
+ if (bs->backing) {
+ BlockDriverState *backing_hd = bs->backing->bs;
bdrv_set_backing_hd(bs, NULL);
bdrv_unref(backing_hd);
}
@@ -2205,20 +2204,20 @@
if (!drv)
return -ENOMEDIUM;
- if (!bs->backing_hd) {
+ if (!bs->backing) {
return -ENOTSUP;
}
if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, NULL) ||
- bdrv_op_is_blocked(bs->backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET, NULL)) {
+ bdrv_op_is_blocked(bs->backing->bs, BLOCK_OP_TYPE_COMMIT_TARGET, NULL)) {
return -EBUSY;
}
- ro = bs->backing_hd->read_only;
- open_flags = bs->backing_hd->open_flags;
+ ro = bs->backing->bs->read_only;
+ open_flags = bs->backing->bs->open_flags;
if (ro) {
- if (bdrv_reopen(bs->backing_hd, open_flags | BDRV_O_RDWR, NULL)) {
+ if (bdrv_reopen(bs->backing->bs, open_flags | BDRV_O_RDWR, NULL)) {
return -EACCES;
}
}
@@ -2229,7 +2228,7 @@
goto ro_cleanup;
}
- backing_length = bdrv_getlength(bs->backing_hd);
+ backing_length = bdrv_getlength(bs->backing->bs);
if (backing_length < 0) {
ret = backing_length;
goto ro_cleanup;
@@ -2239,7 +2238,7 @@
* grow the backing file image if possible. If not possible,
* we must return an error */
if (length > backing_length) {
- ret = bdrv_truncate(bs->backing_hd, length);
+ ret = bdrv_truncate(bs->backing->bs, length);
if (ret < 0) {
goto ro_cleanup;
}
@@ -2248,7 +2247,7 @@
total_sectors = length >> BDRV_SECTOR_BITS;
/* qemu_try_blockalign() for bs will choose an alignment that works for
- * bs->backing_hd as well, so no need to compare the alignment manually. */
+ * bs->backing->bs as well, so no need to compare the alignment manually. */
buf = qemu_try_blockalign(bs, COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
if (buf == NULL) {
ret = -ENOMEM;
@@ -2266,7 +2265,7 @@
goto ro_cleanup;
}
- ret = bdrv_write(bs->backing_hd, sector, buf, n);
+ ret = bdrv_write(bs->backing->bs, sector, buf, n);
if (ret < 0) {
goto ro_cleanup;
}
@@ -2285,8 +2284,8 @@
* Make sure all data we wrote to the backing device is actually
* stable on disk.
*/
- if (bs->backing_hd) {
- bdrv_flush(bs->backing_hd);
+ if (bs->backing) {
+ bdrv_flush(bs->backing->bs);
}
ret = 0;
@@ -2295,7 +2294,7 @@
if (ro) {
/* ignoring error return here */
- bdrv_reopen(bs->backing_hd, open_flags & ~BDRV_O_RDWR, NULL);
+ bdrv_reopen(bs->backing->bs, open_flags & ~BDRV_O_RDWR, NULL);
}
return ret;
@@ -2309,7 +2308,7 @@
AioContext *aio_context = bdrv_get_aio_context(bs);
aio_context_acquire(aio_context);
- if (bs->drv && bs->backing_hd) {
+ if (bs->drv && bs->backing) {
int ret = bdrv_commit(bs);
if (ret < 0) {
aio_context_release(aio_context);
@@ -2366,8 +2365,8 @@
BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
BlockDriverState *bs)
{
- while (active && bs != active->backing_hd) {
- active = active->backing_hd;
+ while (active && bs != backing_bs(active)) {
+ active = backing_bs(active);
}
return active;
@@ -2437,9 +2436,9 @@
goto exit;
}
- /* special case of new_top_bs->backing_hd already pointing to base - nothing
+ /* special case of new_top_bs->backing->bs already pointing to base - nothing
* to do, no intermediate images */
- if (new_top_bs->backing_hd == base) {
+ if (backing_bs(new_top_bs) == base) {
ret = 0;
goto exit;
}
@@ -2454,11 +2453,11 @@
intermediate_state->bs = intermediate;
QSIMPLEQ_INSERT_TAIL(&states_to_delete, intermediate_state, entry);
- if (intermediate->backing_hd == base) {
- base_bs = intermediate->backing_hd;
+ if (backing_bs(intermediate) == base) {
+ base_bs = backing_bs(intermediate);
break;
}
- intermediate = intermediate->backing_hd;
+ intermediate = backing_bs(intermediate);
}
if (base_bs == NULL) {
/* something went wrong, we did not end at the base. safely
@@ -2677,25 +2676,27 @@
int bdrv_is_encrypted(BlockDriverState *bs)
{
- if (bs->backing_hd && bs->backing_hd->encrypted)
+ if (bs->backing && bs->backing->bs->encrypted) {
return 1;
+ }
return bs->encrypted;
}
int bdrv_key_required(BlockDriverState *bs)
{
- BlockDriverState *backing_hd = bs->backing_hd;
+ BdrvChild *backing = bs->backing;
- if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
+ if (backing && backing->bs->encrypted && !backing->bs->valid_key) {
return 1;
+ }
return (bs->encrypted && !bs->valid_key);
}
int bdrv_set_key(BlockDriverState *bs, const char *key)
{
int ret;
- if (bs->backing_hd && bs->backing_hd->encrypted) {
- ret = bdrv_set_key(bs->backing_hd, key);
+ if (bs->backing && bs->backing->bs->encrypted) {
+ ret = bdrv_set_key(bs->backing->bs, key);
if (ret < 0)
return ret;
if (!bs->encrypted)
@@ -2862,7 +2863,7 @@
bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base)
{
while (top && top != base) {
- top = top->backing_hd;
+ top = backing_bs(top);
}
return top != NULL;
@@ -2920,7 +2921,7 @@
/* If BS is a copy on write image, it is initialized to
the contents of the base image, which may not be zeroes. */
- if (bs->backing_hd) {
+ if (bs->backing) {
return 0;
}
if (bs->drv->bdrv_has_zero_init) {
@@ -2935,7 +2936,7 @@
{
BlockDriverInfo bdi;
- if (bs->backing_hd) {
+ if (bs->backing) {
return false;
}
@@ -2950,7 +2951,7 @@
{
BlockDriverInfo bdi;
- if (bs->backing_hd || !(bs->open_flags & BDRV_O_UNMAP)) {
+ if (bs->backing || !(bs->open_flags & BDRV_O_UNMAP)) {
return false;
}
@@ -2963,7 +2964,7 @@
const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
{
- if (bs->backing_hd && bs->backing_hd->encrypted)
+ if (bs->backing && bs->backing->bs->encrypted)
return bs->backing_file;
else if (bs->encrypted)
return bs->filename;
@@ -3088,13 +3089,13 @@
is_protocol = path_has_protocol(backing_file);
- for (curr_bs = bs; curr_bs->backing_hd; curr_bs = curr_bs->backing_hd) {
+ for (curr_bs = bs; curr_bs->backing; curr_bs = curr_bs->backing->bs) {
/* If either of the filename paths is actually a protocol, then
* compare unmodified paths; otherwise make paths relative */
if (is_protocol || path_has_protocol(curr_bs->backing_file)) {
if (strcmp(backing_file, curr_bs->backing_file) == 0) {
- retval = curr_bs->backing_hd;
+ retval = curr_bs->backing->bs;
break;
}
} else {
@@ -3118,7 +3119,7 @@
}
if (strcmp(backing_file_full, filename_full) == 0) {
- retval = curr_bs->backing_hd;
+ retval = curr_bs->backing->bs;
break;
}
}
@@ -3136,11 +3137,11 @@
return 0;
}
- if (!bs->backing_hd) {
+ if (!bs->backing) {
return 0;
}
- return 1 + bdrv_get_backing_file_depth(bs->backing_hd);
+ return 1 + bdrv_get_backing_file_depth(bs->backing->bs);
}
void bdrv_init(void)
@@ -3903,8 +3904,8 @@
if (bs->file) {
bdrv_detach_aio_context(bs->file->bs);
}
- if (bs->backing_hd) {
- bdrv_detach_aio_context(bs->backing_hd);
+ if (bs->backing) {
+ bdrv_detach_aio_context(bs->backing->bs);
}
bs->aio_context = NULL;
@@ -3921,8 +3922,8 @@
bs->aio_context = new_context;
- if (bs->backing_hd) {
- bdrv_attach_aio_context(bs->backing_hd, new_context);
+ if (bs->backing) {
+ bdrv_attach_aio_context(bs->backing->bs, new_context);
}
if (bs->file) {
bdrv_attach_aio_context(bs->file->bs, new_context);
