qemu/migration
Fabiano Rosas 8b1eac90bb block-migration: Ensure we don't crash during migration cleanup
We can fail the blk_insert_bs() at init_blk_migration(), leaving the
BlkMigDevState without a dirty_bitmap and BlockDriverState. Account
for the possibly missing elements when doing cleanup.

Fix the following crashes:

Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x0000555555ec83ef in bdrv_release_dirty_bitmap (bitmap=0x0) at ../block/dirty-bitmap.c:359
359         BlockDriverState *bs = bitmap->bs;
 #0  0x0000555555ec83ef in bdrv_release_dirty_bitmap (bitmap=0x0) at ../block/dirty-bitmap.c:359
 #1  0x0000555555bba331 in unset_dirty_tracking () at ../migration/block.c:371
 #2  0x0000555555bbad98 in block_migration_cleanup_bmds () at ../migration/block.c:681

Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x0000555555e971ff in bdrv_op_unblock (bs=0x0, op=BLOCK_OP_TYPE_BACKUP_SOURCE, reason=0x0) at ../block.c:7073
7073        QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) {
 #0  0x0000555555e971ff in bdrv_op_unblock (bs=0x0, op=BLOCK_OP_TYPE_BACKUP_SOURCE, reason=0x0) at ../block.c:7073
 #1  0x0000555555e9734a in bdrv_op_unblock_all (bs=0x0, reason=0x0) at ../block.c:7095
 #2  0x0000555555bbae13 in block_migration_cleanup_bmds () at ../migration/block.c:690

Signed-off-by: Fabiano Rosas <farosas@suse.de>
Message-id: 20230731203338.27581-1-farosas@suse.de
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit f187609f27)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2023-09-11 10:53:50 +03:00
..
block-dirty-bitmap.c
block.c block-migration: Ensure we don't crash during migration cleanup 2023-09-11 10:53:50 +03:00
block.h
channel-block.c
channel-block.h
channel.c
channel.h
colo-failover.c
colo.c
dirtyrate.c
dirtyrate.h
exec.c
exec.h
fd.c
fd.h
global_state.c
meson.build
migration.c
migration.h
multifd-zlib.c
multifd-zstd.c
multifd.c
multifd.h
page_cache.c
page_cache.h
postcopy-ram.c
postcopy-ram.h
qemu-file.c
qemu-file.h
ram.c
ram.h
rdma.c
rdma.h
savevm.c
savevm.h
socket.c
socket.h
target.c
tls.c
tls.h
trace-events
trace.h
vmstate-types.c
vmstate.c
xbzrle.c
xbzrle.h
yank_functions.c
yank_functions.h