[Libguestfs] [libnbd PATCH 0/4] Work towards fixing nbdcopy silent corruption

These are the trivial patches modeled after Nir's commit 7ba6ef67, fixing further places that fail to check *error during callbacks. nbdcopy still has a bigger bug in that it is NOT properly checking for *error in the pread/pwrite completion handlers, but fixing that gracefully (rather than just quitting the process immediately, as we can do in the examples), requires more invasive patches which I will be posting separately for review, while the ones posted here are trivial enough that I'm pushing them now (commits 23bcea4a..1373d423). I also audited other uses of completion callbacks: - in tests, closure-lifetimes, errors, server-death, and shutdown-flags are all safe (either the callback returns 0 and the code later calls nbd_aio_command_completed, or we are explicitly testing aspects of completion callbacks) - in fuse/operations.c, the completion callback returns 0 and calls nbd_aio_command_completed later - in examples/strict-structured-reads.c, the completion callback properly checks *error I also checked that nbdkit's nbd plugin properly checks *error. Eric Blake (4): examples: aio-connect-read.c: Fix error handling examples: glib-main-loop: don't strand commands when gsource disappears examples: glib-main-loop: Fix error handling copy: Ignore extents if we encountered earlier error examples/aio-connect-read.c | 7 +++++++ examples/glib-main-loop.c | 14 ++++++++++++-- copy/nbd-ops.c | 4 ++-- 3 files changed, 21 insertions(+), 4 deletions(-) -- 2.34.1