diff options
Diffstat (limited to 'mm/filemap.c')
| -rw-r--r-- | mm/filemap.c | 94 |
1 files changed, 58 insertions, 36 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 462cda58a18e..26b992d169e5 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1301,40 +1301,38 @@ static int fastcall page_cache_read(struct file * file, unsigned long offset) #define MMAP_LOTSAMISS (100) /** - * filemap_nopage - read in file data for page fault handling - * @area: the applicable vm_area - * @address: target address to read in - * @type: returned with VM_FAULT_{MINOR,MAJOR} if not %NULL + * filemap_fault - read in file data for page fault handling + * @vma: user vma (not used) + * @fdata: the applicable fault_data * - * filemap_nopage() is invoked via the vma operations vector for a + * filemap_fault() is invoked via the vma operations vector for a * mapped memory region to read in file data during a page fault. * * The goto's are kind of ugly, but this streamlines the normal case of having * it in the page cache, and handles the special cases reasonably without * having a lot of duplicated code. */ -struct page *filemap_nopage(struct vm_area_struct *area, - unsigned long address, int *type) +struct page *filemap_fault(struct vm_area_struct *vma, struct fault_data *fdata) { int error; - struct file *file = area->vm_file; + struct file *file = vma->vm_file; struct address_space *mapping = file->f_mapping; struct file_ra_state *ra = &file->f_ra; struct inode *inode = mapping->host; struct page *page; - unsigned long size, pgoff; - int did_readaround = 0, majmin = VM_FAULT_MINOR; + unsigned long size; + int did_readaround = 0; - BUG_ON(!(area->vm_flags & VM_CAN_INVALIDATE)); + fdata->type = VM_FAULT_MINOR; - pgoff = ((address-area->vm_start) >> PAGE_CACHE_SHIFT) + area->vm_pgoff; + BUG_ON(!(vma->vm_flags & VM_CAN_INVALIDATE)); size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; - if (pgoff >= size) + if (fdata->pgoff >= size) goto outside_data_content; /* If we don't want any read-ahead, don't bother */ - if (VM_RandomReadHint(area)) + if (VM_RandomReadHint(vma)) goto no_cached_page; /* @@ -1343,19 +1341,19 @@ struct page *filemap_nopage(struct vm_area_struct *area, * * For sequential accesses, we use the generic readahead logic. */ - if (VM_SequentialReadHint(area)) - page_cache_readahead(mapping, ra, file, pgoff, 1); + if (VM_SequentialReadHint(vma)) + page_cache_readahead(mapping, ra, file, fdata->pgoff, 1); /* * Do we have something in the page cache already? */ retry_find: - page = find_lock_page(mapping, pgoff); + page = find_lock_page(mapping, fdata->pgoff); if (!page) { unsigned long ra_pages; - if (VM_SequentialReadHint(area)) { - handle_ra_miss(mapping, ra, pgoff); + if (VM_SequentialReadHint(vma)) { + handle_ra_miss(mapping, ra, fdata->pgoff); goto no_cached_page; } ra->mmap_miss++; @@ -1372,7 +1370,7 @@ retry_find: * check did_readaround, as this is an inner loop. */ if (!did_readaround) { - majmin = VM_FAULT_MAJOR; + fdata->type = VM_FAULT_MAJOR; count_vm_event(PGMAJFAULT); } did_readaround = 1; @@ -1380,11 +1378,11 @@ retry_find: if (ra_pages) { pgoff_t start = 0; - if (pgoff > ra_pages / 2) - start = pgoff - ra_pages / 2; + if (fdata->pgoff > ra_pages / 2) + start = fdata->pgoff - ra_pages / 2; do_page_cache_readahead(mapping, file, start, ra_pages); } - page = find_lock_page(mapping, pgoff); + page = find_lock_page(mapping, fdata->pgoff); if (!page) goto no_cached_page; } @@ -1401,7 +1399,7 @@ retry_find: /* Must recheck i_size under page lock */ size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; - if (unlikely(pgoff >= size)) { + if (unlikely(fdata->pgoff >= size)) { unlock_page(page); goto outside_data_content; } @@ -1410,8 +1408,6 @@ retry_find: * Found the page and have a reference on it. */ mark_page_accessed(page); - if (type) - *type = majmin; return page; outside_data_content: @@ -1419,15 +1415,17 @@ outside_data_content: * An external ptracer can access pages that normally aren't * accessible.. */ - if (area->vm_mm == current->mm) - return NOPAGE_SIGBUS; + if (vma->vm_mm == current->mm) { + fdata->type = VM_FAULT_SIGBUS; + return NULL; + } /* Fall through to the non-read-ahead case */ no_cached_page: /* * We're only likely to ever get here if MADV_RANDOM is in * effect. */ - error = page_cache_read(file, pgoff); + error = page_cache_read(file, fdata->pgoff); /* * The page we want has now been added to the page cache. @@ -1443,13 +1441,15 @@ no_cached_page: * to schedule I/O. */ if (error == -ENOMEM) - return NOPAGE_OOM; - return NOPAGE_SIGBUS; + fdata->type = VM_FAULT_OOM; + else + fdata->type = VM_FAULT_SIGBUS; + return NULL; page_not_uptodate: /* IO error path */ if (!did_readaround) { - majmin = VM_FAULT_MAJOR; + fdata->type = VM_FAULT_MAJOR; count_vm_event(PGMAJFAULT); } @@ -1468,7 +1468,30 @@ page_not_uptodate: /* Things didn't work out. Return zero to tell the mm layer so. */ shrink_readahead_size_eio(file, ra); - return NOPAGE_SIGBUS; + fdata->type = VM_FAULT_SIGBUS; + return NULL; +} +EXPORT_SYMBOL(filemap_fault); + +/* + * filemap_nopage and filemap_populate are legacy exports that are not used + * in tree. Scheduled for removal. + */ +struct page *filemap_nopage(struct vm_area_struct *area, + unsigned long address, int *type) +{ + struct page *page; + struct fault_data fdata; + fdata.address = address; + fdata.pgoff = ((address - area->vm_start) >> PAGE_CACHE_SHIFT) + + area->vm_pgoff; + fdata.flags = 0; + + page = filemap_fault(area, &fdata); + if (type) + *type = fdata.type; + + return page; } EXPORT_SYMBOL(filemap_nopage); @@ -1646,8 +1669,7 @@ repeat: EXPORT_SYMBOL(filemap_populate); struct vm_operations_struct generic_file_vm_ops = { - .nopage = filemap_nopage, - .populate = filemap_populate, + .fault = filemap_fault, }; /* This is used for a general mmap of a disk file */ @@ -1660,7 +1682,7 @@ int generic_file_mmap(struct file * file, struct vm_area_struct * vma) return -ENOEXEC; file_accessed(file); vma->vm_ops = &generic_file_vm_ops; - vma->vm_flags |= VM_CAN_INVALIDATE; + vma->vm_flags |= VM_CAN_INVALIDATE | VM_CAN_NONLINEAR; return 0; } |