struct page *page;
pte_t _dst_pte, *dst_pte;
int ret;
+ pgoff_t offset, max_off;
ret = -ENOMEM;
if (!shmem_inode_acct_block(inode, 1))
__SetPageSwapBacked(page);
__SetPageUptodate(page);
+ ret = -EFAULT;
+ offset = linear_page_index(dst_vma, dst_addr);
+ max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
+ if (unlikely(offset >= max_off))
+ goto out_release;
+
ret = mem_cgroup_try_charge(page, dst_mm, gfp, &memcg, false);
if (ret)
goto out_release;
_dst_pte = mk_pte(page, dst_vma->vm_page_prot);
if (dst_vma->vm_flags & VM_WRITE)
_dst_pte = pte_mkwrite(pte_mkdirty(_dst_pte));
+ else {
+ /*
+ * We don't set the pte dirty if the vma has no
+ * VM_WRITE permission, so mark the page dirty or it
+ * could be freed from under us. We could do it
+ * unconditionally before unlock_page(), but doing it
+ * only if VM_WRITE is not set is faster.
+ */
+ set_page_dirty(page);
+ }
- ret = -EEXIST;
dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl);
+
+ ret = -EFAULT;
+ max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
+ if (unlikely(offset >= max_off))
+ goto out_release_uncharge_unlock;
+
+ ret = -EEXIST;
if (!pte_none(*dst_pte))
goto out_release_uncharge_unlock;
/* No need to invalidate - it was non-present before */
update_mmu_cache(dst_vma, dst_addr, dst_pte);
- unlock_page(page);
pte_unmap_unlock(dst_pte, ptl);
+ unlock_page(page);
ret = 0;
out:
return ret;
out_release_uncharge_unlock:
pte_unmap_unlock(dst_pte, ptl);
+ ClearPageDirty(page);
+ delete_from_page_cache(page);
out_release_uncharge:
mem_cgroup_cancel_charge(page, memcg, false);
out_release: