+/* Sharing code of page_mkwrite method for rhel5 and rhel6 */
+static int ll_page_mkwrite0(struct vm_area_struct *vma, struct page *vmpage,
+ bool *retry)
+{
+ struct lu_env *env;
+ struct cl_io *io;
+ struct vvp_io *vio;
+ struct cl_env_nest nest;
+ int result;
+ cfs_sigset_t set;
+ ENTRY;
+
+ LASSERT(vmpage != NULL);
+
+ io = ll_fault_io_init(vma, &env, &nest, vmpage->index, NULL);
+ if (IS_ERR(io))
+ GOTO(out, result = PTR_ERR(io));
+
+ result = io->ci_result;
+ if (result < 0)
+ GOTO(out, result);
+
+ /* Don't enqueue new locks for page_mkwrite().
+ * If the lock has been cancelled then page must have been
+ * truncated, in that case, kernel will handle it.
+ */
+ io->ci_lockreq = CILR_PEEK;
+ io->u.ci_fault.ft_mkwrite = 1;
+ io->u.ci_fault.ft_writable = 1;
+
+ vio = vvp_env_io(env);
+ vio->u.fault.ft_vma = vma;
+ vio->u.fault.ft_vmpage = vmpage;
+
+ set = cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM));
+ result = cl_io_loop(env, io);
+ cfs_restore_sigs(set);
+
+ if (result == -ENODATA) /* peek failed, no lock caching. */
+ CDEBUG(D_MMAP, "race on page_mkwrite: %lx (%lu %p)\n",
+ vma->vm_flags, io->u.ci_fault.ft_index, vmpage);
+
+ if (result == 0 || result == -ENODATA) {
+ lock_page(vmpage);
+ if (vmpage->mapping == NULL) {
+ unlock_page(vmpage);
+
+ /* page was truncated and lock was cancelled, return
+ * ENODATA so that VM_FAULT_NOPAGE will be returned
+ * to handle_mm_fault(). */
+ if (result == 0)
+ result = -ENODATA;
+ } else if (result == -ENODATA) {
+ /* Invalidate it if the cl_lock is being revoked.
+ * This piece of code is definitely needed for RHEL5,
+ * otherwise, SIGBUS will be wrongly returned to
+ * applications. */
+ write_one_page(vmpage, 1);
+ lock_page(vmpage);
+ if (vmpage->mapping != NULL) {
+ ll_invalidate_page(vmpage);
+ LASSERT(vmpage->mapping == NULL);
+ }
+ unlock_page(vmpage);
+ } else if (!PageDirty(vmpage)) {
+ /* race, the page has been cleaned by ptlrpcd after
+ * it was unlocked, it has to be added into dirty
+ * cache again otherwise this soon-to-dirty page won't
+ * consume any grants, even worse if this page is being
+ * transferred because it will break RPC checksum.
+ */
+ unlock_page(vmpage);
+
+ CDEBUG(D_MMAP, "Race on page_mkwrite %p/%lu, page has "
+ "been written out, retry.\n",
+ vmpage, vmpage->index);
+
+ *retry = true;
+ result = -EAGAIN;
+ }
+ }
+ EXIT;
+
+out:
+ cl_io_fini(env, io);
+ cl_env_nested_put(&nest, env);
+
+ CDEBUG(D_MMAP, "%s mkwrite with %d\n", cfs_current()->comm, result);
+
+ LASSERT(ergo(result == 0, PageLocked(vmpage)));
+ return(result);
+}
+
+