1 files changed, 127 insertions, 80 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index 23acefe51808..ccea3b665c12 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -121,7 +121,6 @@ void __remove_from_page_cache(struct page *page)
 	mapping->nrpages--;
 	__dec_zone_page_state(page, NR_FILE_PAGES);
 	BUG_ON(page_mapped(page));
-	mem_cgroup_uncharge_cache_page(page);
 
 	/*
 	 * Some filesystems seem to re-dirty the page even after
@@ -145,6 +144,7 @@ void remove_from_page_cache(struct page *page)
 	spin_lock_irq(&mapping->tree_lock);
 	__remove_from_page_cache(page);
 	spin_unlock_irq(&mapping->tree_lock);
+	mem_cgroup_uncharge_cache_page(page);
 }
 
 static int sync_page(void *word)
@@ -441,6 +441,7 @@ int filemap_write_and_wait_range(struct address_space *mapping,
 	}
 	return err;
 }
+EXPORT_SYMBOL(filemap_write_and_wait_range);
 
 /**
  * add_to_page_cache_locked - add a locked page to the pagecache
@@ -475,13 +476,13 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
 		if (likely(!error)) {
 			mapping->nrpages++;
 			__inc_zone_page_state(page, NR_FILE_PAGES);
+			spin_unlock_irq(&mapping->tree_lock);
 		} else {
 			page->mapping = NULL;
+			spin_unlock_irq(&mapping->tree_lock);
 			mem_cgroup_uncharge_cache_page(page);
 			page_cache_release(page);
 		}
-
-		spin_unlock_irq(&mapping->tree_lock);
 		radix_tree_preload_end();
 	} else
 		mem_cgroup_uncharge_cache_page(page);
@@ -513,13 +514,14 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
 	}
 	return ret;
 }
+EXPORT_SYMBOL_GPL(add_to_page_cache_lru);
 
 #ifdef CONFIG_NUMA
 struct page *__page_cache_alloc(gfp_t gfp)
 {
 	if (cpuset_do_page_mem_spread()) {
 		int n = cpuset_mem_spread_node();
-		return alloc_pages_node(n, gfp, 0);
+		return alloc_pages_exact_node(n, gfp, 0);
 	}
 	return alloc_pages(gfp, 0);
 }
@@ -565,6 +567,24 @@ void wait_on_page_bit(struct page *page, int bit_nr)
 EXPORT_SYMBOL(wait_on_page_bit);
 
 /**
+ * add_page_wait_queue - Add an arbitrary waiter to a page's wait queue
+ * @page: Page defining the wait queue of interest
+ * @waiter: Waiter to add to the queue
+ *
+ * Add an arbitrary @waiter to the wait queue for the nominated @page.
+ */
+void add_page_wait_queue(struct page *page, wait_queue_t *waiter)
+{
+	wait_queue_head_t *q = page_waitqueue(page);
+	unsigned long flags;
+
+	spin_lock_irqsave(&q->lock, flags);
+	__add_wait_queue(q, waiter);
+	spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL_GPL(add_page_wait_queue);
+
+/**
  * unlock_page - unlock a locked page
  * @page: the page
  *
@@ -627,6 +647,7 @@ int __lock_page_killable(struct page *page)
 	return __wait_on_bit_lock(page_waitqueue(page), &wait,
 					sync_page_killable, TASK_KILLABLE);
 }
+EXPORT_SYMBOL_GPL(__lock_page_killable);
 
 /**
  * __lock_page_nosync - get a lock on the page, without calling sync_page()
@@ -983,9 +1004,6 @@ EXPORT_SYMBOL(grab_cache_page_nowait);
 static void shrink_readahead_size_eio(struct file *filp,
 					struct file_ra_state *ra)
 {
-	if (!ra->ra_pages)
-		return;
-
 	ra->ra_pages /= 4;
 }
 
@@ -1369,8 +1387,7 @@ do_readahead(struct address_space *mapping, struct file *filp,
 	if (!mapping || !mapping->a_ops || !mapping->a_ops->readpage)
 		return -EINVAL;
 
-	force_page_cache_readahead(mapping, filp, index,
-					max_sane_readahead(nr));
+	force_page_cache_readahead(mapping, filp, index, nr);
 	return 0;
 }
 
@@ -1436,6 +1453,73 @@ static int page_cache_read(struct file *file, pgoff_t offset)
 
 #define MMAP_LOTSAMISS  (100)
 
+/*
+ * Synchronous readahead happens when we don't even find
+ * a page in the page cache at all.
+ */
+static void do_sync_mmap_readahead(struct vm_area_struct *vma,
+				   struct file_ra_state *ra,
+				   struct file *file,
+				   pgoff_t offset)
+{
+	unsigned long ra_pages;
+	struct address_space *mapping = file->f_mapping;
+
+	/* If we don't want any read-ahead, don't bother */
+	if (VM_RandomReadHint(vma))
+		return;
+
+	if (VM_SequentialReadHint(vma) ||
+			offset - 1 == (ra->prev_pos >> PAGE_CACHE_SHIFT)) {
+		page_cache_sync_readahead(mapping, ra, file, offset,
+					  ra->ra_pages);
+		return;
+	}
+
+	if (ra->mmap_miss < INT_MAX)
+		ra->mmap_miss++;
+
+	/*
+	 * Do we miss much more than hit in this file? If so,
+	 * stop bothering with read-ahead. It will only hurt.
+	 */
+	if (ra->mmap_miss > MMAP_LOTSAMISS)
+		return;
+
+	/*
+	 * mmap read-around
+	 */
+	ra_pages = max_sane_readahead(ra->ra_pages);
+	if (ra_pages) {
+		ra->start = max_t(long, 0, offset - ra_pages/2);
+		ra->size = ra_pages;
+		ra->async_size = 0;
+		ra_submit(ra, mapping, file);
+	}
+}
+
+/*
+ * Asynchronous readahead happens when we find the page and PG_readahead,
+ * so we want to possibly extend the readahead further..
+ */
+static void do_async_mmap_readahead(struct vm_area_struct *vma,
+				    struct file_ra_state *ra,
+				    struct file *file,
+				    struct page *page,
+				    pgoff_t offset)
+{
+	struct address_space *mapping = file->f_mapping;
+
+	/* If we don't want any read-ahead, don't bother */
+	if (VM_RandomReadHint(vma))
+		return;
+	if (ra->mmap_miss > 0)
+		ra->mmap_miss--;
+	if (PageReadahead(page))
+		page_cache_async_readahead(mapping, ra, file,
+					   page, offset, ra->ra_pages);
+}
+
 /**
  * filemap_fault - read in file data for page fault handling
  * @vma:	vma in which the fault was taken
@@ -1455,78 +1539,44 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	struct address_space *mapping = file->f_mapping;
 	struct file_ra_state *ra = &file->f_ra;
 	struct inode *inode = mapping->host;
+	pgoff_t offset = vmf->pgoff;
 	struct page *page;
 	pgoff_t size;
-	int did_readaround = 0;
 	int ret = 0;
 
 	size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-	if (vmf->pgoff >= size)
+	if (offset >= size)
 		return VM_FAULT_SIGBUS;
 
-	/* If we don't want any read-ahead, don't bother */
-	if (VM_RandomReadHint(vma))
-		goto no_cached_page;
-
 	/*
 	 * Do we have something in the page cache already?
 	 */
-retry_find:
-	page = find_lock_page(mapping, vmf->pgoff);
-	/*
-	 * For sequential accesses, we use the generic readahead logic.
-	 */
-	if (VM_SequentialReadHint(vma)) {
-		if (!page) {
-			page_cache_sync_readahead(mapping, ra, file,
-							   vmf->pgoff, 1);
-			page = find_lock_page(mapping, vmf->pgoff);
-			if (!page)
-				goto no_cached_page;
-		}
-		if (PageReadahead(page)) {
-			page_cache_async_readahead(mapping, ra, file, page,
-							   vmf->pgoff, 1);
-		}
-	}
-
-	if (!page) {
-		unsigned long ra_pages;
-
-		ra->mmap_miss++;
-
+	page = find_get_page(mapping, offset);
+	if (likely(page)) {
 		/*
-		 * Do we miss much more than hit in this file? If so,
-		 * stop bothering with read-ahead. It will only hurt.
+		 * We found the page, so try async readahead before
+		 * waiting for the lock.
 		 */
-		if (ra->mmap_miss > MMAP_LOTSAMISS)
-			goto no_cached_page;
+		do_async_mmap_readahead(vma, ra, file, page, offset);
+		lock_page(page);
 
-		/*
-		 * To keep the pgmajfault counter straight, we need to
-		 * check did_readaround, as this is an inner loop.
-		 */
-		if (!did_readaround) {
-			ret = VM_FAULT_MAJOR;
-			count_vm_event(PGMAJFAULT);
-		}
-		did_readaround = 1;
-		ra_pages = max_sane_readahead(file->f_ra.ra_pages);
-		if (ra_pages) {
-			pgoff_t start = 0;
-
-			if (vmf->pgoff > ra_pages / 2)
-				start = vmf->pgoff - ra_pages / 2;
-			do_page_cache_readahead(mapping, file, start, ra_pages);
+		/* Did it get truncated? */
+		if (unlikely(page->mapping != mapping)) {
+			unlock_page(page);
+			put_page(page);
+			goto no_cached_page;
 		}
-		page = find_lock_page(mapping, vmf->pgoff);
+	} else {
+		/* No page in the page cache at all */
+		do_sync_mmap_readahead(vma, ra, file, offset);
+		count_vm_event(PGMAJFAULT);
+		ret = VM_FAULT_MAJOR;
+retry_find:
+		page = find_lock_page(mapping, offset);
 		if (!page)
 			goto no_cached_page;
 	}
 
-	if (!did_readaround)
-		ra->mmap_miss--;
-
 	/*
 	 * We have a locked page in the page cache, now we need to check
 	 * that it's up-to-date. If not, it is going to be due to an error.
@@ -1534,18 +1584,18 @@ retry_find:
 	if (unlikely(!PageUptodate(page)))
 		goto page_not_uptodate;
 
-	/* Must recheck i_size under page lock */
+	/*
+	 * Found the page and have a reference on it.
+	 * We must recheck i_size under page lock.
+	 */
 	size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-	if (unlikely(vmf->pgoff >= size)) {
+	if (unlikely(offset >= size)) {
 		unlock_page(page);
 		page_cache_release(page);
 		return VM_FAULT_SIGBUS;
 	}
 
-	/*
-	 * Found the page and have a reference on it.
-	 */
-	ra->prev_pos = (loff_t)page->index << PAGE_CACHE_SHIFT;
+	ra->prev_pos = (loff_t)offset << PAGE_CACHE_SHIFT;
 	vmf->page = page;
 	return ret | VM_FAULT_LOCKED;
 
@@ -1554,7 +1604,7 @@ no_cached_page:
 	 * We're only likely to ever get here if MADV_RANDOM is in
 	 * effect.
 	 */
-	error = page_cache_read(file, vmf->pgoff);
+	error = page_cache_read(file, offset);
 
 	/*
 	 * The page we want has now been added to the page cache.
@@ -1574,12 +1624,6 @@ no_cached_page:
 	return VM_FAULT_SIGBUS;
 
 page_not_uptodate:
-	/* IO error path */
-	if (!did_readaround) {
-		ret = VM_FAULT_MAJOR;
-		count_vm_event(PGMAJFAULT);
-	}
-
 	/*
 	 * Umm, take care of errors if the page isn't up-to-date.
 	 * Try to re-read it _once_. We do this synchronously,
@@ -1823,7 +1867,7 @@ static size_t __iovec_copy_from_user_inatomic(char *vaddr,
 		int copy = min(bytes, iov->iov_len - base);
 
 		base = 0;
-		left = __copy_from_user_inatomic_nocache(vaddr, buf, copy);
+		left = __copy_from_user_inatomic(vaddr, buf, copy);
 		copied += copy;
 		bytes -= copy;
 		vaddr += copy;
@@ -1851,8 +1895,7 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
 	if (likely(i->nr_segs == 1)) {
 		int left;
 		char __user *buf = i->iov->iov_base + i->iov_offset;
-		left = __copy_from_user_inatomic_nocache(kaddr + offset,
-							buf, bytes);
+		left = __copy_from_user_inatomic(kaddr + offset, buf, bytes);
 		copied = bytes - left;
 	} else {
 		copied = __iovec_copy_from_user_inatomic(kaddr + offset,
@@ -1880,7 +1923,7 @@ size_t iov_iter_copy_from_user(struct page *page,
 	if (likely(i->nr_segs == 1)) {
 		int left;
 		char __user *buf = i->iov->iov_base + i->iov_offset;
-		left = __copy_from_user_nocache(kaddr + offset, buf, bytes);
+		left = __copy_from_user(kaddr + offset, buf, bytes);
 		copied = bytes - left;
 	} else {
 		copied = __iovec_copy_from_user_inatomic(kaddr + offset,
@@ -2229,6 +2272,7 @@ again:
 		pagefault_enable();
 		flush_dcache_page(page);
 
+		mark_page_accessed(page);
 		status = a_ops->write_end(file, mapping, pos, bytes, copied,
 						page, fsdata);
 		if (unlikely(status < 0))
@@ -2464,6 +2508,9 @@ EXPORT_SYMBOL(generic_file_aio_write);
  * (presumably at page->private).  If the release was successful, return `1'.
  * Otherwise return zero.
  *
+ * This may also be called if PG_fscache is set on a page, indicating that the
+ * page is known to the local caching routines.
+ *
  * The @gfp_mask argument specifies whether I/O may be performed to release
  * this page (__GFP_IO), and whether the call may block (__GFP_WAIT & __GFP_FS).
  *