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block: Close a BlockDriverState completely even when bs->drv is NULL

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bdrv_close() skips much of its logic when bs->drv is NULL. This is
fine when we're closing a BlockDriverState that has just been created
(because e.g the initialization process failed), but it's not enough
in other cases.

For example, when a valid qcow2 image is found to be corrupted then
QEMU marks it as such in the file header and then sets bs->drv to
NULL in order to make the BlockDriverState unusable. When that BDS is
later closed then many of its data structures are not freed (leaking
their memory) and none of its children are detached. This results in
bdrv_close_all() failing to close all BDSs and making this assertion
fail when QEMU is being shut down:

   bdrv_close_all: Assertion `QTAILQ_EMPTY(&all_bdrv_states)' failed.

This patch makes bdrv_close() do the full uninitialization process
in all cases. This fixes the problem with corrupted images and still
works fine with freshly created BDSs.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 20171106145345.12038-1-berto@igalia.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Alberto Garcia 2017-11-06 16:53:45 +02:00 committed by Max Reitz
parent 70a5afedd6
commit 50a3efb0f0
3 changed files with 57 additions and 33 deletions
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65
block.c
View File

@ -3198,6 +3198,7 @@ void bdrv_reopen_abort(BDRVReopenState *reopen_state)
static void bdrv_close(BlockDriverState *bs)
{
BdrvAioNotifier *ban, *ban_next;
BdrvChild *child, *next;
assert(!bs->job);
assert(!bs->refcnt);
@ -3207,43 +3208,41 @@ static void bdrv_close(BlockDriverState *bs)
bdrv_drain(bs); /* in case flush left pending I/O */
if (bs->drv) {
BdrvChild *child, *next;
bs->drv->bdrv_close(bs);
bs->drv = NULL;
bdrv_set_backing_hd(bs, NULL, &error_abort);
if (bs->file != NULL) {
bdrv_unref_child(bs, bs->file);
bs->file = NULL;
}
QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
/* TODO Remove bdrv_unref() from drivers' close function and use
* bdrv_unref_child() here */
if (child->bs->inherits_from == bs) {
child->bs->inherits_from = NULL;
}
bdrv_detach_child(child);
}
g_free(bs->opaque);
bs->opaque = NULL;
atomic_set(&bs->copy_on_read, 0);
bs->backing_file[0] = '\0';
bs->backing_format[0] = '\0';
bs->total_sectors = 0;
bs->encrypted = false;
bs->sg = false;
QDECREF(bs->options);
QDECREF(bs->explicit_options);
bs->options = NULL;
bs->explicit_options = NULL;
QDECREF(bs->full_open_options);
bs->full_open_options = NULL;
}
bdrv_set_backing_hd(bs, NULL, &error_abort);
if (bs->file != NULL) {
bdrv_unref_child(bs, bs->file);
bs->file = NULL;
}
QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
/* TODO Remove bdrv_unref() from drivers' close function and use
* bdrv_unref_child() here */
if (child->bs->inherits_from == bs) {
child->bs->inherits_from = NULL;
}
bdrv_detach_child(child);
}
g_free(bs->opaque);
bs->opaque = NULL;
atomic_set(&bs->copy_on_read, 0);
bs->backing_file[0] = '\0';
bs->backing_format[0] = '\0';
bs->total_sectors = 0;
bs->encrypted = false;
bs->sg = false;
QDECREF(bs->options);
QDECREF(bs->explicit_options);
bs->options = NULL;
bs->explicit_options = NULL;
QDECREF(bs->full_open_options);
bs->full_open_options = NULL;
bdrv_release_named_dirty_bitmaps(bs);
assert(QLIST_EMPTY(&bs->dirty_bitmaps));

13
tests/qemu-iotests/060
View File

@ -426,6 +426,19 @@ echo '--- Repairing ---'
_check_test_img -q -r all
_check_test_img -r all
echo
echo "=== Testing the QEMU shutdown with a corrupted image ==="
echo
_make_test_img 64M
poke_file "$TEST_IMG" "$rt_offset" "\x00\x00\x00\x00\x00\x00\x00\x00"
echo "{'execute': 'qmp_capabilities'}
{'execute': 'human-monitor-command',
'arguments': {'command-line': 'qemu-io drive \"write 0 512\"'}}
{'execute': 'quit'}" \
| $QEMU -qmp stdio -nographic -nodefaults \
-drive if=none,node-name=drive,file="$TEST_IMG",driver=qcow2 \
| _filter_qmp | _filter_qemu_io
# success, all done
echo "*** done"
rm -f $seq.full

12
tests/qemu-iotests/060.out
View File

@ -399,4 +399,16 @@ The following inconsistencies were found and repaired:
Double checking the fixed image now...
No errors were found on the image.
=== Testing the QEMU shutdown with a corrupted image ===
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
qcow2: Marking image as corrupt: Preventing invalid write on metadata (overlaps with refcount table); further corruption events will be suppressed
QMP_VERSION
{"return": {}}
{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "BLOCK_IMAGE_CORRUPTED", "data": {"device": "none0", "msg": "Preventing invalid write on metadata (overlaps with refcount table)", "offset": 65536, "node-name": "drive", "fatal": true, "size": 65536}}
write failed: Input/output error
{"return": ""}
{"return": {}}
{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false}}
*** done