140dedb81c
was still possible to open for write from the lower filesystem. There is a symmetric situation where the binary could already has file descriptors opened for write, but it can be executed from the nullfs overlay. Handle the issue by passing one v_writecount reference to the lower vnode if nullfs vnode has non-zero v_writecount. Note that only one write reference can be donated, since nullfs only keeps one use reference on the lower vnode. Always use the lower vnode v_writecount for the checks. Introduce the VOP_GET_WRITECOUNT to read v_writecount, which is currently always bypassed to the lower vnode, and VOP_ADD_WRITECOUNT to manipulate the v_writecount value, which manages a single bypass reference to the lower vnode. Caling the VOPs instead of directly accessing v_writecount provide the fix described in the previous paragraph. Tested by: pho MFC after: 3 weeks |
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.. | ||
check_error.d | ||
check_internal_locks.d | ||
linux_dtrace.h | ||
linux_emul.c | ||
linux_emul.h | ||
linux_file.c | ||
linux_file.h | ||
linux_fork.c | ||
linux_futex.c | ||
linux_futex.h | ||
linux_getcwd.c | ||
linux_ioctl.c | ||
linux_ioctl.h | ||
linux_ipc.c | ||
linux_ipc.h | ||
linux_mib.c | ||
linux_mib.h | ||
linux_misc.c | ||
linux_misc.h | ||
linux_signal.c | ||
linux_signal.h | ||
linux_socket.c | ||
linux_socket.h | ||
linux_stats.c | ||
linux_sysctl.c | ||
linux_sysproto.h | ||
linux_time.c | ||
linux_uid16.c | ||
linux_util.c | ||
linux_util.h | ||
linux_videodev2_compat.h | ||
linux_videodev2.h | ||
linux_videodev_compat.h | ||
linux_videodev.h | ||
stats_timing.d | ||
trace_futexes.d |