1 files changed, 37 insertions, 17 deletions

diff --git a/kernel/fs/direct-io.c b/kernel/fs/direct-io.c
index 745d23426..01171d8a6 100644
--- a/kernel/fs/direct-io.c
+++ b/kernel/fs/direct-io.c
@@ -109,6 +109,8 @@ struct dio_submit {
 struct dio {
 	int flags;			/* doesn't change */
 	int rw;
+	blk_qc_t bio_cookie;
+	struct block_device *bio_bdev;
 	struct inode *inode;
 	loff_t i_size;			/* i_size when submitted */
 	dio_iodone_t *end_io;		/* IO completion function */
@@ -120,6 +122,7 @@ struct dio {
 	int page_errors;		/* errno from get_user_pages() */
 	int is_async;			/* is IO async ? */
 	bool defer_completion;		/* defer AIO completion to workqueue? */
+	bool should_dirty;		/* if pages should be dirtied */
 	int io_error;			/* IO error in completion path */
 	unsigned long refcount;		/* direct_io_worker() and bios */
 	struct bio *bio_list;		/* singly linked via bi_private */
@@ -285,7 +288,7 @@ static int dio_bio_complete(struct dio *dio, struct bio *bio);
 /*
  * Asynchronous IO callback. 
  */
-static void dio_bio_end_aio(struct bio *bio, int error)
+static void dio_bio_end_aio(struct bio *bio)
 {
 	struct dio *dio = bio->bi_private;
 	unsigned long remaining;
@@ -318,7 +321,7 @@ static void dio_bio_end_aio(struct bio *bio, int error)
  * During I/O bi_private points at the dio.  After I/O, bi_private is used to
  * implement a singly-linked list of completed BIOs, at dio->bio_list.
  */
-static void dio_bio_end_io(struct bio *bio, int error)
+static void dio_bio_end_io(struct bio *bio)
 {
 	struct dio *dio = bio->bi_private;
 	unsigned long flags;
@@ -345,9 +348,9 @@ void dio_end_io(struct bio *bio, int error)
 	struct dio *dio = bio->bi_private;
 
 	if (dio->is_async)
-		dio_bio_end_aio(bio, error);
+		dio_bio_end_aio(bio);
 	else
-		dio_bio_end_io(bio, error);
+		dio_bio_end_io(bio);
 }
 EXPORT_SYMBOL_GPL(dio_end_io);
 
@@ -360,7 +363,7 @@ dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
 
 	/*
 	 * bio_alloc() is guaranteed to return a bio when called with
-	 * __GFP_WAIT and we request a valid number of vectors.
+	 * __GFP_RECLAIM and we request a valid number of vectors.
 	 */
 	bio = bio_alloc(GFP_KERNEL, nr_vecs);
 
@@ -393,14 +396,17 @@ static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)
 	dio->refcount++;
 	spin_unlock_irqrestore(&dio->bio_lock, flags);
 
-	if (dio->is_async && dio->rw == READ)
+	if (dio->is_async && dio->rw == READ && dio->should_dirty)
 		bio_set_pages_dirty(bio);
 
-	if (sdio->submit_io)
+	dio->bio_bdev = bio->bi_bdev;
+
+	if (sdio->submit_io) {
 		sdio->submit_io(dio->rw, bio, dio->inode,
 			       sdio->logical_offset_in_bio);
-	else
-		submit_bio(dio->rw, bio);
+		dio->bio_cookie = BLK_QC_T_NONE;
+	} else
+		dio->bio_cookie = submit_bio(dio->rw, bio);
 
 	sdio->bio = NULL;
 	sdio->boundary = 0;
@@ -439,7 +445,8 @@ static struct bio *dio_await_one(struct dio *dio)
 		__set_current_state(TASK_UNINTERRUPTIBLE);
 		dio->waiter = current;
 		spin_unlock_irqrestore(&dio->bio_lock, flags);
-		io_schedule();
+		if (!blk_poll(bdev_get_queue(dio->bio_bdev), dio->bio_cookie))
+			io_schedule();
 		/* wake up sets us TASK_RUNNING */
 		spin_lock_irqsave(&dio->bio_lock, flags);
 		dio->waiter = NULL;
@@ -457,26 +464,29 @@ static struct bio *dio_await_one(struct dio *dio)
  */
 static int dio_bio_complete(struct dio *dio, struct bio *bio)
 {
-	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 	struct bio_vec *bvec;
 	unsigned i;
+	int err;
 
-	if (!uptodate)
+	if (bio->bi_error)
 		dio->io_error = -EIO;
 
-	if (dio->is_async && dio->rw == READ) {
+	if (dio->is_async && dio->rw == READ && dio->should_dirty) {
+		err = bio->bi_error;
 		bio_check_pages_dirty(bio);	/* transfers ownership */
 	} else {
 		bio_for_each_segment_all(bvec, bio, i) {
 			struct page *page = bvec->bv_page;
 
-			if (dio->rw == READ && !PageCompound(page))
+			if (dio->rw == READ && !PageCompound(page) &&
+					dio->should_dirty)
 				set_page_dirty_lock(page);
 			page_cache_release(page);
 		}
+		err = bio->bi_error;
 		bio_put(bio);
 	}
-	return uptodate ? 0 : -EIO;
+	return err;
 }
 
 /*
@@ -653,7 +663,7 @@ static inline int dio_new_bio(struct dio *dio, struct dio_submit *sdio,
 	if (ret)
 		goto out;
 	sector = start_sector << (sdio->blkbits - 9);
-	nr_pages = min(sdio->pages_in_io, bio_get_nr_vecs(map_bh->b_bdev));
+	nr_pages = min(sdio->pages_in_io, BIO_MAX_PAGES);
 	BUG_ON(nr_pages <= 0);
 	dio_bio_alloc(dio, sdio, map_bh->b_bdev, sector, nr_pages);
 	sdio->boundary = 0;
@@ -1159,6 +1169,16 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
 		}
 	}
 
+	/* Once we sampled i_size check for reads beyond EOF */
+	dio->i_size = i_size_read(inode);
+	if (iov_iter_rw(iter) == READ && offset >= dio->i_size) {
+		if (dio->flags & DIO_LOCKING)
+			mutex_unlock(&inode->i_mutex);
+		kmem_cache_free(dio_cache, dio);
+		retval = 0;
+		goto out;
+	}
+
 	/*
 	 * For file extending writes updating i_size before data writeouts
 	 * complete can expose uninitialized blocks in dumb filesystems.
@@ -1212,11 +1232,11 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
 	sdio.next_block_for_io = -1;
 
 	dio->iocb = iocb;
-	dio->i_size = i_size_read(inode);
 
 	spin_lock_init(&dio->bio_lock);
 	dio->refcount = 1;
 
+	dio->should_dirty = (iter->type == ITER_IOVEC);
 	sdio.iter = iter;
 	sdio.final_block_in_request =
 		(offset + iov_iter_count(iter)) >> blkbits;