[PATCH 0/2] qemu: Improve opening and verifying save images

qemuSaveImageOpen does a lot of stuff. When bypass-cache is specified, it creates a virFileWrapperFd, which is not cleaned up in the subsequent failure paths. This results in errors from the iohelper, which can overwrite the actual error. E.g. consider libvirt attempting to restore an image saved in an unknown format # virsh restore --bypass-cache /data/test.sav.sparse error: Failed to restore domain from /data/test.sav.sparse error: internal error: Child process (LIBVIRT_LOG_OUTPUTS=1:stderr /usr/lib64/libvirt/libvirt_iohelper /data/test.sav.sparse 0) unexpected fatal signal 13 When not using the iohelper, and not creating a virFileWrapperFd, we see the real error: # virsh restore /data/test.sav.sparse error: Failed to restore domain from /data/test.sav.sparse error: operation failed: Invalid compressed save format 6 Although that error highlights a spot I missed when removing the "compression" implications around the 'foo_image_format' settings in qemu.conf with commit bd6d7ebf622 :-). IMO, the error message would be best fixed by checking for valid values when reading the save image metadata. Patch 1 decomposes qemuSaveImageOpen to allow for better error handling and more flexibility. Patch 2 checks for a valid format when checking the other header fields. Jim Fehlig (2): qemu: Decompose qemuSaveImageOpen qemu: Check for valid save image format when verifying image header src/qemu/qemu_driver.c | 37 +++++++-------- src/qemu/qemu_saveimage.c | 95 +++++++++++++++++++++++++-------------- src/qemu/qemu_saveimage.h | 16 ++++--- src/qemu/qemu_snapshot.c | 9 ++-- 4 files changed, 95 insertions(+), 62 deletions(-) -- 2.43.0