Merge branch 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git...

[cascardo/linux.git] / mm / filemap.c

diff --git a/mm/filemap.c b/mm/filemap.c
index 2d0986a..849f459 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -169,33 +169,35 @@ static int page_cache_tree_insert(struct address_space *mapping,
 static void page_cache_tree_delete(struct address_space *mapping,
                                   struct page *page, void *shadow)
 {
-       struct radix_tree_node *node;
        int i, nr = PageHuge(page) ? 1 : hpage_nr_pages(page);
 
        VM_BUG_ON_PAGE(!PageLocked(page), page);
        VM_BUG_ON_PAGE(PageTail(page), page);
        VM_BUG_ON_PAGE(nr != 1 && shadow, page);
 
-       if (shadow) {
-               mapping->nrexceptional += nr;
-               /*
-                * Make sure the nrexceptional update is committed before
-                * the nrpages update so that final truncate racing
-                * with reclaim does not see both counters 0 at the
-                * same time and miss a shadow entry.
-                */
-               smp_wmb();
-       }
-       mapping->nrpages -= nr;
-
        for (i = 0; i < nr; i++) {
-               node = radix_tree_replace_clear_tags(&mapping->page_tree,
-                               page->index + i, shadow);
+               struct radix_tree_node *node;
+               void **slot;
+
+               __radix_tree_lookup(&mapping->page_tree, page->index + i,
+                                   &node, &slot);
+
+               radix_tree_clear_tags(&mapping->page_tree, node, slot);
+
                if (!node) {
                        VM_BUG_ON_PAGE(nr != 1, page);
-                       return;
+                       /*
+                        * We need a node to properly account shadow
+                        * entries. Don't plant any without. XXX
+                        */
+                       shadow = NULL;
                }
 
+               radix_tree_replace_slot(slot, shadow);
+
+               if (!node)
+                       break;
+
                workingset_node_pages_dec(node);
                if (shadow)
                        workingset_node_shadows_inc(node);
@@ -219,6 +221,18 @@ static void page_cache_tree_delete(struct address_space *mapping,
                                        &node->private_list);
                }
        }
+
+       if (shadow) {
+               mapping->nrexceptional += nr;
+               /*
+                * Make sure the nrexceptional update is committed before
+                * the nrpages update so that final truncate racing
+                * with reclaim does not see both counters 0 at the
+                * same time and miss a shadow entry.
+                */
+               smp_wmb();
+       }
+       mapping->nrpages -= nr;
 }
 
 /*
@@ -619,7 +633,6 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
                __delete_from_page_cache(old, NULL);
                error = page_cache_tree_insert(mapping, new, NULL);
                BUG_ON(error);
-               mapping->nrpages++;
 
                /*
                 * hugetlb pages do not participate in page cache accounting.
@@ -1674,6 +1687,10 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos,
        unsigned int prev_offset;
        int error = 0;
 
+       if (unlikely(*ppos >= inode->i_sb->s_maxbytes))
+               return -EINVAL;
+       iov_iter_truncate(iter, inode->i_sb->s_maxbytes);
+
        index = *ppos >> PAGE_SHIFT;
        prev_index = ra->prev_pos >> PAGE_SHIFT;
        prev_offset = ra->prev_pos & (PAGE_SIZE-1);
@@ -1708,7 +1725,9 @@ find_page:
                         * wait_on_page_locked is used to avoid unnecessarily
                         * serialisations and why it's safe.
                         */
-                       wait_on_page_locked_killable(page);
+                       error = wait_on_page_locked_killable(page);
+                       if (unlikely(error))
+                               goto readpage_error;
                        if (PageUptodate(page))
                                goto page_ok;
 
@@ -1910,17 +1929,19 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
        if (iocb->ki_flags & IOCB_DIRECT) {
                struct address_space *mapping = file->f_mapping;
                struct inode *inode = mapping->host;
+               struct iov_iter data = *iter;
                loff_t size;
 
                size = i_size_read(inode);
                retval = filemap_write_and_wait_range(mapping, iocb->ki_pos,
                                        iocb->ki_pos + count - 1);
-               if (!retval) {
-                       struct iov_iter data = *iter;
-                       retval = mapping->a_ops->direct_IO(iocb, &data);
-               }
+               if (retval < 0)
+                       goto out;
 
-               if (retval > 0) {
+               file_accessed(file);
+
+               retval = mapping->a_ops->direct_IO(iocb, &data);
+               if (retval >= 0) {
                        iocb->ki_pos += retval;
                        iov_iter_advance(iter, retval);
                }
@@ -1935,10 +1956,8 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
                 * DAX files, so don't bother trying.
                 */
                if (retval < 0 || !iov_iter_count(iter) || iocb->ki_pos >= size ||
-                   IS_DAX(inode)) {
-                       file_accessed(file);
+                   IS_DAX(inode))
                        goto out;
-               }
        }
 
        retval = do_generic_file_read(file, &iocb->ki_pos, iter, retval);