V2: 1: all fail case will goto fail section. 2: add the goto code. v3: Address Stefan's comments: 2: don't goto fail after allocation failure. 3: use sn->l1size correctly in qcow2_free_cluster(). 4-7: add test case to verify the error paths. Other: 1: new patch fix a existing bug, which will be exposed in error path test.
v4: General change: rebased on upstream since error path for qcow2_write_snapshots() already exist in upstream. removed old patch 1 since it is fixed by Max in upstream. 5: moved the snapshot_l1_update event just before write operation, instead of before overlap check, since it is more straight. 6: remove a duplicated error path test about flush after snapshot list update, add a filter which replace number to X, since now in error in report detailed message including error cluster number. Address Stefan's comments: 1, 2, 4: add *errp to store detailed error message, instead of error_report() and compile time determined debug printf message. 3: do not free cluster when fail in header update for safety reason. Address Eric's comments: 1, 2, 4: add *errp to store detailed error message, instead of error_report() and compile time determined debug printf message. 5: squashed patches that add and use debug events. 6: added comments about test only on Linux. v5: General change: 6: rebased on upstream, use case number 070, adjust 070.out due to error message change in this version. Address Max's comments: 1 use error_setg_errno() when possible, remove "ret =" in functions when possible since the function does not need to return int value, fix 32bit/ 64bit issue in printf for "sizeof" and "offse", typo fix. 2 use error_setg_errno() when possible, fix 32bit/64bit issue in printf for "sizeof" and "offse", typo fix. 3 typo fix in comments. 5 typo fix in commit message. Address Eric's comments: 2 fix 32bit/64bit issue in printf for "sizeof" and "offse". v6: Address Jeff's comments: 6: add quote for image name in test case. Wenchao Xia (6): 1 snapshot: add parameter *errp in snapshot create 2 qcow2: add error message in qcow2_write_snapshots() 3 qcow2: do not free clusters when fail in header update in qcow2_write_snapshots 4 qcow2: cancel the modification on fail in qcow2_snapshot_create() 5 blkdebug: add debug events for snapshot 6 qemu-iotests: add test for qcow2 snapshot block/blkdebug.c | 4 + block/qcow2-snapshot.c | 105 ++++++++++++++++--- block/qcow2.h | 4 +- block/rbd.c | 19 ++-- block/sheepdog.c | 28 +++-- block/snapshot.c | 19 +++- blockdev.c | 10 +- include/block/block.h | 4 + include/block/block_int.h | 5 +- include/block/snapshot.h | 5 +- qemu-img.c | 10 +- savevm.c | 12 ++- tests/qemu-iotests/070 | 216 ++++++++++++++++++++++++++++++++++++++ tests/qemu-iotests/070.out | 35 ++++++ tests/qemu-iotests/common.filter | 7 ++ tests/qemu-iotests/group | 1 + 16 files changed, 427 insertions(+), 57 deletions(-) create mode 100755 tests/qemu-iotests/070 create mode 100644 tests/qemu-iotests/070.out