In case of cow fault when there is no page mapped at cow location, we return VM_FAULT_LOCKED despite we don't return any page from the fault. The code in do_cow_fault() carefully handled the case when no page was actually returned so no harm was done but still this is a bug waiting to happen. Signed-off-by: Jan Kara <jack@xxxxxxx> --- fs/dax.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/dax.c b/fs/dax.c index 4aa440f9305b..bf39f16e5390 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -680,7 +680,9 @@ int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, if (error) goto unlock_page; vmf->page = page; - return VM_FAULT_LOCKED; + if (page) + return VM_FAULT_LOCKED; + return 0; } /* Check we didn't race with a read fault installing a new page */ -- 2.6.2 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
