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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.. | ||
default_pager.c | ||
device_pager.c | ||
memguard.c | ||
memguard.h | ||
phys_pager.c | ||
pmap.h | ||
redzone.c | ||
redzone.h | ||
sg_pager.c | ||
swap_pager.c | ||
swap_pager.h | ||
uma_core.c | ||
uma_dbg.c | ||
uma_dbg.h | ||
uma_int.h | ||
uma.h | ||
vm_extern.h | ||
vm_fault.c | ||
vm_glue.c | ||
vm_init.c | ||
vm_kern.c | ||
vm_kern.h | ||
vm_map.c | ||
vm_map.h | ||
vm_meter.c | ||
vm_mmap.c | ||
vm_object.c | ||
vm_object.h | ||
vm_page.c | ||
vm_page.h | ||
vm_pageout.c | ||
vm_pageout.h | ||
vm_pager.c | ||
vm_pager.h | ||
vm_param.h | ||
vm_phys.c | ||
vm_phys.h | ||
vm_reserv.c | ||
vm_reserv.h | ||
vm_unix.c | ||
vm_zeroidle.c | ||
vm.h | ||
vnode_pager.c | ||
vnode_pager.h |