diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-10-24 00:01:43 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-10-24 00:01:43 -0300 |
commit | 037d32aa8f748e39844d2a5b607fb063b4583843 (patch) | |
tree | b5fe973d42017b5d8888103b05be7a503fe95f0f /mm/filemap.c | |
parent | 670027c507e99521d416994a18a498def9ef2ea3 (diff) |
Linux-libre 4.8.4-gnupck-4.8.4-gnu
Diffstat (limited to 'mm/filemap.c')
-rw-r--r-- | mm/filemap.c | 51 |
1 files changed, 34 insertions, 17 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 4a31bad51..ea47a7de5 100644 --- 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); |