tree 948bd5a3b739d67377bd32e45d8d2ad69d481046
parent f0e0c46309dac41a8420bcb379b1cffa7da0f62c
author Kevin Wolf <kwolf@redhat.com> 1719511964 +0200
committer Kevin Wolf <kwolf@redhat.com> 1722967959 +0200

block-copy: Fix missing graph lock

The graph lock needs to be held when calling bdrv_co_pdiscard(). Fix
block_copy_task_entry() to take it for the call.

WITH_GRAPH_RDLOCK_GUARD() was implemented in a weak way because of
limitations in clang's Thread Safety Analysis at the time, so that it
only asserts that the lock is held (which allows calling functions that
require the lock), but we never deal with the unlocking (so even after
the scope of the guard, the compiler assumes that the lock is still
held). This is why the compiler didn't catch this locking error.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20240627181245.281403-2-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>