X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Ffremap.c;h=95bcb5641c722b6f4d7eb49801320e0a266f7c83;hb=535131e6925b4a95f321148ad7293f496e0e58d7;hp=b77a002c3352f7c91898b75b6636cc60e3ceadc2;hpb=21b4e736922f546e0f1aa7b9d6c442f309a2444a;p=linux-2.6 diff --git a/mm/fremap.c b/mm/fremap.c index b77a002c33..95bcb5641c 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -20,83 +20,37 @@ #include #include -static int zap_pte(struct mm_struct *mm, struct vm_area_struct *vma, +static void zap_pte(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { pte_t pte = *ptep; - struct page *page = NULL; if (pte_present(pte)) { + struct page *page; + flush_cache_page(vma, addr, pte_pfn(pte)); pte = ptep_clear_flush(vma, addr, ptep); page = vm_normal_page(vma, addr, pte); if (page) { if (pte_dirty(pte)) set_page_dirty(page); - page_remove_rmap(page); + page_remove_rmap(page, vma); page_cache_release(page); + update_hiwater_rss(mm); + dec_mm_counter(mm, file_rss); } } else { if (!pte_file(pte)) free_swap_and_cache(pte_to_swp_entry(pte)); pte_clear_not_present_full(mm, addr, ptep, 0); } - return !!page; } -/* - * Install a file page to a given virtual memory address, release any - * previously existing mapping. - */ -int install_page(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, struct page *page, pgprot_t prot) -{ - struct inode *inode; - pgoff_t size; - int err = -ENOMEM; - pte_t *pte; - pte_t pte_val; - spinlock_t *ptl; - - pte = get_locked_pte(mm, addr, &ptl); - if (!pte) - goto out; - - /* - * This page may have been truncated. Tell the - * caller about it. - */ - err = -EINVAL; - inode = vma->vm_file->f_mapping->host; - size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; - if (!page->mapping || page->index >= size) - goto unlock; - err = -ENOMEM; - if (page_mapcount(page) > INT_MAX/2) - goto unlock; - - if (pte_none(*pte) || !zap_pte(mm, vma, addr, pte)) - inc_mm_counter(mm, file_rss); - - flush_icache_page(vma, page); - pte_val = mk_pte(page, prot); - set_pte_at(mm, addr, pte, pte_val); - page_add_file_rmap(page); - update_mmu_cache(vma, addr, pte_val); - lazy_mmu_prot_update(pte_val); - err = 0; -unlock: - pte_unmap_unlock(pte, ptl); -out: - return err; -} -EXPORT_SYMBOL(install_page); - /* * Install a file pte to a given virtual memory address, release any * previously existing mapping. */ -int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, +static int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, unsigned long pgoff, pgprot_t prot) { int err = -ENOMEM; @@ -107,10 +61,8 @@ int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, if (!pte) goto out; - if (!pte_none(*pte) && zap_pte(mm, vma, addr, pte)) { - update_hiwater_rss(mm); - dec_mm_counter(mm, file_rss); - } + if (!pte_none(*pte)) + zap_pte(mm, vma, addr, pte); set_pte_at(mm, addr, pte, pgoff_to_pte(pgoff)); /* @@ -126,6 +78,25 @@ out: return err; } +static int populate_range(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long addr, unsigned long size, pgoff_t pgoff) +{ + int err; + + do { + err = install_file_pte(mm, vma, addr, pgoff, vma->vm_page_prot); + if (err) + return err; + + size -= PAGE_SIZE; + addr += PAGE_SIZE; + pgoff++; + } while (size); + + return 0; + +} + /*** * sys_remap_file_pages - remap arbitrary pages of a shared backing store * file within an existing vma. @@ -183,41 +154,77 @@ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size, * the single existing vma. vm_private_data is used as a * swapout cursor in a VM_NONLINEAR vma. */ - if (vma && (vma->vm_flags & VM_SHARED) && - (!vma->vm_private_data || (vma->vm_flags & VM_NONLINEAR)) && - vma->vm_ops && vma->vm_ops->populate && - end > start && start >= vma->vm_start && - end <= vma->vm_end) { - - /* Must set VM_NONLINEAR before any pages are populated. */ - if (pgoff != linear_page_index(vma, start) && - !(vma->vm_flags & VM_NONLINEAR)) { - if (!has_write_lock) { - up_read(&mm->mmap_sem); - down_write(&mm->mmap_sem); - has_write_lock = 1; - goto retry; - } - mapping = vma->vm_file->f_mapping; - spin_lock(&mapping->i_mmap_lock); - flush_dcache_mmap_lock(mapping); - vma->vm_flags |= VM_NONLINEAR; - vma_prio_tree_remove(vma, &mapping->i_mmap); - vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear); - flush_dcache_mmap_unlock(mapping); - spin_unlock(&mapping->i_mmap_lock); - } + if (!vma || !(vma->vm_flags & VM_SHARED)) + goto out; - err = vma->vm_ops->populate(vma, start, size, - vma->vm_page_prot, - pgoff, flags & MAP_NONBLOCK); + if (vma->vm_private_data && !(vma->vm_flags & VM_NONLINEAR)) + goto out; + + if (!(vma->vm_flags & VM_CAN_NONLINEAR)) + goto out; + if (end <= start || start < vma->vm_start || end > vma->vm_end) + goto out; + + /* Must set VM_NONLINEAR before any pages are populated. */ + if (!(vma->vm_flags & VM_NONLINEAR)) { + /* Don't need a nonlinear mapping, exit success */ + if (pgoff == linear_page_index(vma, start)) { + err = 0; + goto out; + } + + if (!has_write_lock) { + up_read(&mm->mmap_sem); + down_write(&mm->mmap_sem); + has_write_lock = 1; + goto retry; + } + mapping = vma->vm_file->f_mapping; /* - * We can't clear VM_NONLINEAR because we'd have to do - * it after ->populate completes, and that would prevent - * downgrading the lock. (Locks can't be upgraded). + * page_mkclean doesn't work on nonlinear vmas, so if + * dirty pages need to be accounted, emulate with linear + * vmas. */ + if (mapping_cap_account_dirty(mapping)) { + unsigned long addr; + + flags &= MAP_NONBLOCK; + addr = mmap_region(vma->vm_file, start, size, + flags, vma->vm_flags, pgoff, 1); + if (IS_ERR_VALUE(addr)) { + err = addr; + } else { + BUG_ON(addr != start); + err = 0; + } + goto out; + } + spin_lock(&mapping->i_mmap_lock); + flush_dcache_mmap_lock(mapping); + vma->vm_flags |= VM_NONLINEAR; + vma_prio_tree_remove(vma, &mapping->i_mmap); + vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear); + flush_dcache_mmap_unlock(mapping); + spin_unlock(&mapping->i_mmap_lock); + } + + err = populate_range(mm, vma, start, size, pgoff); + if (!err && !(flags & MAP_NONBLOCK)) { + if (unlikely(has_write_lock)) { + downgrade_write(&mm->mmap_sem); + has_write_lock = 0; + } + make_pages_present(start, start+size); } + + /* + * We can't clear VM_NONLINEAR because we'd have to do + * it after ->populate completes, and that would prevent + * downgrading the lock. (Locks can't be upgraded). + */ + +out: if (likely(!has_write_lock)) up_read(&mm->mmap_sem); else