[LU-11703] sigbus on shared mapping memset

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Labels: patch
• Severity: 3
• Assignee: Vladimir Saveliev
• Reporter: Vladimir Saveliev

Description

The following test

    addr = mmap(.., MAP_SHARED, ..);

    for(;;)
        memcpy(addr, ...);

leads to sigbus signal as vvp_io_fault_start() runs out of grants.

static int vvp_io_fault_start(const struct lu_env *env,
                              const struct cl_io_slice *ios)
...
                        result = cl_io_commit_async(env, io, plist, 0, to,
                                                    mkwrite_commit_callback);
...
                                /* we're in big trouble, what can we do now? */
                                if (result == -EDQUOT)
                                        result = -ENOSPC;