5 files changed, 234 insertions, 41 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index ccb4dbf..b491576 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -127,10 +127,11 @@ struct mpage_da_data {
 	int pages_written;
 	int retval;
 };
-
+#define	DIO_AIO_UNWRITTEN	0x1
 typedef struct ext4_io_end {
+	struct list_head	list;		/* per-file finished AIO list */
 	struct inode		*inode;		/* file being written to */
-	unsigned int		flag;		/* sync IO or AIO */
+	unsigned int		flag;		/* unwritten or not */
 	int			error;		/* I/O error code */
 	ext4_lblk_t		offset;		/* offset in the file */
 	size_t			size;		/* size of the extent */
@@ -690,6 +691,11 @@ struct ext4_inode_info {
 	__u16 i_extra_isize;
 
 	spinlock_t i_block_reservation_lock;
+
+	/* completed async DIOs that might need unwritten extents handling */
+	struct list_head i_aio_dio_complete_list;
+	/* current io_end structure for async DIO write*/
+	ext4_io_end_t *cur_aio_dio;
 };
 
 /*
@@ -1419,7 +1425,7 @@ extern int ext4_block_truncate_page(handle_t *handle,
 		struct address_space *mapping, loff_t from);
 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
 extern qsize_t ext4_get_reserved_space(struct inode *inode);
-
+extern int flush_aio_dio_completed_IO(struct inode *inode);
 /* ioctl.c */
 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index a38e651..10a6309 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3033,6 +3033,7 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
 {
 	int ret = 0;
 	int err = 0;
+	ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
 
 	ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical"
 		  "block %llu, max_blocks %u, flags %d, allocated %u",
@@ -3045,6 +3046,9 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
 		ret = ext4_split_unwritten_extents(handle,
 						inode, path, iblock,
 						max_blocks, flags);
+		/* flag the io_end struct that we need convert when IO done */
+		if (io)
+			io->flag = DIO_AIO_UNWRITTEN;
 		goto out;
 	}
 	/* DIO end_io complete, convert the filled extent to written */
@@ -3130,6 +3134,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 	int err = 0, depth, ret, cache_type;
 	unsigned int allocated = 0;
 	struct ext4_allocation_request ar;
+	ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
 
 	__clear_bit(BH_New, &bh_result->b_state);
 	ext_debug("blocks %u/%u requested for inode %lu\n",
@@ -3279,8 +3284,20 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 	/* try to insert new extent into found leaf and return */
 	ext4_ext_store_pblock(&newex, newblock);
 	newex.ee_len = cpu_to_le16(ar.len);
-	if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)  /* Mark uninitialized */
+	/* Mark uninitialized */
+	if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){
 		ext4_ext_mark_uninitialized(&newex);
+		/*
+		 * io_end structure was created for every async
+		 * direct IO write to the middle of the file.
+		 * To avoid unecessary convertion for every aio dio rewrite
+		 * to the mid of file, here we flag the IO that is really
+		 * need the convertion.
+		 *
+		 */
+		if (io && flags == EXT4_GET_BLOCKS_DIO_CREATE_EXT)
+			io->flag = DIO_AIO_UNWRITTEN;
+	}
 	err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
 	if (err) {
 		/* free data blocks we just allocated */
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index 0747574..2b15312 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -44,6 +44,8 @@
  *
  * What we do is just kick off a commit and wait on it.  This will snapshot the
  * inode to disk.
+ *
+ * i_mutex lock is held when entering and exiting this function
  */
 
 int ext4_sync_file(struct file *file, struct dentry *dentry, int datasync)
@@ -56,6 +58,9 @@ int ext4_sync_file(struct file *file, struct dentry *dentry, int datasync)
 
 	trace_ext4_sync_file(file, dentry, datasync);
 
+	ret = flush_aio_dio_completed_IO(inode);
+	if (ret < 0)
+		goto out;
 	/*
 	 * data=writeback:
 	 *  The caller's filemap_fdatawrite()/wait will sync the data.
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 5633af6..118e16c 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3451,6 +3451,8 @@ static int ext4_get_block_dio_write(struct inode *inode, sector_t iblock,
 	unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
 	int dio_credits;
 
+	ext4_debug("ext4_get_block_dio_write: inode %lu, create flag %d\n",
+		   inode->i_ino, create);
 	/*
 	 * DIO VFS code passes create = 0 flag for write to
 	 * the middle of file. It does this to avoid block
@@ -3491,55 +3493,152 @@ out:
 	return ret;
 }
 
-#define		DIO_AIO		0x1
-
 static void ext4_free_io_end(ext4_io_end_t *io)
 {
+	BUG_ON(!io);
+	iput(io->inode);
 	kfree(io);
 }
+static void dump_aio_dio_list(struct inode * inode)
+{
+#ifdef	EXT4_DEBUG
+	struct list_head *cur, *before, *after;
+	ext4_io_end_t *io, *io0, *io1;
+
+	if (list_empty(&EXT4_I(inode)->i_aio_dio_complete_list)){
+		ext4_debug("inode %lu aio dio list is empty\n", inode->i_ino);
+		return;
+	}
+
+	ext4_debug("Dump inode %lu aio_dio_completed_IO list \n", inode->i_ino);
+	list_for_each_entry(io, &EXT4_I(inode)->i_aio_dio_complete_list, list){
+		cur = &io->list;
+		before = cur->prev;
+		io0 = container_of(before, ext4_io_end_t, list);
+		after = cur->next;
+		io1 = container_of(after, ext4_io_end_t, list);
+
+		ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n",
+			    io, inode->i_ino, io0, io1);
+	}
+#endif
+}
 
 /*
- * IO write completion for unwritten extents.
- *
  * check a range of space and convert unwritten extents to written.
  */
-static void ext4_end_dio_unwritten(struct work_struct *work)
+static int ext4_end_aio_dio_nolock(ext4_io_end_t *io)
 {
-	ext4_io_end_t *io = container_of(work, ext4_io_end_t, work);
 	struct inode *inode = io->inode;
 	loff_t offset = io->offset;
 	size_t size = io->size;
 	int ret = 0;
-	int aio = io->flag & DIO_AIO;
 
-	if (aio)
-		mutex_lock(&inode->i_mutex);
+	ext4_debug("end_aio_dio_onlock: io 0x%p from inode %lu,list->next 0x%p,"
+		   "list->prev 0x%p\n",
+	           io, inode->i_ino, io->list.next, io->list.prev);
+
+	if (list_empty(&io->list))
+		return ret;
+
+	if (io->flag != DIO_AIO_UNWRITTEN)
+		return ret;
+
 	if (offset + size <= i_size_read(inode))
 		ret = ext4_convert_unwritten_extents(inode, offset, size);
 
-	if (ret < 0)
+	if (ret < 0) {
 		printk(KERN_EMERG "%s: failed to convert unwritten"
-			"extents to written extents, error is %d\n",
-                       __func__, ret);
+			"extents to written extents, error is %d"
+			" io is still on inode %lu aio dio list\n",
+                       __func__, ret, inode->i_ino);
+		return ret;
+	}
+
+	/* clear the DIO AIO unwritten flag */
+	io->flag = 0;
+	return ret;
+}
+/*
+ * work on completed aio dio IO, to convert unwritten extents to extents
+ */
+static void ext4_end_aio_dio_work(struct work_struct *work)
+{
+	ext4_io_end_t *io  = container_of(work, ext4_io_end_t, work);
+	struct inode *inode = io->inode;
+	int ret = 0;
+
+	mutex_lock(&inode->i_mutex);
+	ret = ext4_end_aio_dio_nolock(io);
+	if (ret >= 0) {
+		if (!list_empty(&io->list))
+			list_del_init(&io->list);
+		ext4_free_io_end(io);
+	}
+	mutex_unlock(&inode->i_mutex);
+}
+/*
+ * This function is called from ext4_sync_file().
+ *
+ * When AIO DIO IO is completed, the work to convert unwritten
+ * extents to written is queued on workqueue but may not get immediately
+ * scheduled. When fsync is called, we need to ensure the
+ * conversion is complete before fsync returns.
+ * The inode keeps track of a list of completed AIO from DIO path
+ * that might needs to do the conversion. This function walks through
+ * the list and convert the related unwritten extents to written.
+ */
+int flush_aio_dio_completed_IO(struct inode *inode)
+{
+	ext4_io_end_t *io;
+	int ret = 0;
+	int ret2 = 0;
 
-	ext4_free_io_end(io);
-	if (aio)
-		mutex_unlock(&inode->i_mutex);
+	if (list_empty(&EXT4_I(inode)->i_aio_dio_complete_list))
+		return ret;
+
+	dump_aio_dio_list(inode);
+	while (!list_empty(&EXT4_I(inode)->i_aio_dio_complete_list)){
+		io = list_entry(EXT4_I(inode)->i_aio_dio_complete_list.next,
+				ext4_io_end_t, list);
+		/*
+		 * Calling ext4_end_aio_dio_nolock() to convert completed
+		 * IO to written.
+		 *
+		 * When ext4_sync_file() is called, run_queue() may already
+		 * about to flush the work corresponding to this io structure.
+		 * It will be upset if it founds the io structure related
+		 * to the work-to-be schedule is freed.
+		 *
+		 * Thus we need to keep the io structure still valid here after
+		 * convertion finished. The io structure has a flag to
+		 * avoid double converting from both fsync and background work
+		 * queue work.
+		 */
+		ret = ext4_end_aio_dio_nolock(io);
+		if (ret < 0)
+			ret2 = ret;
+		else
+			list_del_init(&io->list);
+	}
+	return (ret2 < 0) ? ret2 : 0;
 }
 
-static ext4_io_end_t *ext4_init_io_end (struct inode *inode, unsigned int flag)
+static ext4_io_end_t *ext4_init_io_end (struct inode *inode)
 {
 	ext4_io_end_t *io = NULL;
 
 	io = kmalloc(sizeof(*io), GFP_NOFS);
 
 	if (io) {
+		igrab(inode);
 		io->inode = inode;
-		io->flag = flag;
+		io->flag = 0;
 		io->offset = 0;
 		io->size = 0;
 		io->error = 0;
-		INIT_WORK(&io->work, ext4_end_dio_unwritten);
+		INIT_WORK(&io->work, ext4_end_aio_dio_work);
+		INIT_LIST_HEAD(&io->list);
 	}
 
 	return io;
@@ -3551,19 +3650,31 @@ static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
         ext4_io_end_t *io_end = iocb->private;
 	struct workqueue_struct *wq;
 
-	/* if not hole or unwritten extents, just simple return */
-	if (!io_end || !size || !iocb->private)
+	ext_debug("ext4_end_io_dio(): io_end 0x%p"
+		  "for inode %lu, iocb 0x%p, offset %llu, size %llu\n",
+ 		  iocb->private, io_end->inode->i_ino, iocb, offset,
+		  size);
+	/* if not async direct IO or dio with 0 bytes write, just return */
+	if (!io_end || !size)
 		return;
+
+	/* if not aio dio with unwritten extents, just free io and return */
+	if (io_end->flag != DIO_AIO_UNWRITTEN){
+		ext4_free_io_end(io_end);
+		iocb->private = NULL;
+		return;
+	}
+
 	io_end->offset = offset;
 	io_end->size = size;
 	wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq;
 
-	/* We need to convert unwritten extents to written */
+	/* queue the work to convert unwritten extents to written */
 	queue_work(wq, &io_end->work);
 
-        if (is_sync_kiocb(iocb))
-		flush_workqueue(wq);
-
+	/* Add the io_end to per-inode completed aio dio list*/
+	list_add_tail(&io_end->list,
+		 &EXT4_I(io_end->inode)->i_aio_dio_complete_list);
 	iocb->private = NULL;
 }
 /*
@@ -3575,8 +3686,10 @@ static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
  * If those blocks were preallocated, we mark sure they are splited, but
  * still keep the range to write as unintialized.
  *
- * When end_io call back function called at the last IO complete time,
- * those extents will be converted to written extents.
+ * The unwrritten extents will be converted to written when DIO is completed.
+ * For async direct IO, since the IO may still pending when return, we
+ * set up an end_io call back function, which will do the convertion
+ * when async direct IO completed.
  *
  * If the O_DIRECT write will extend the file then add this inode to the
  * orphan list.  So recovery will truncate it back to the original size
@@ -3595,28 +3708,76 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
 	loff_t final_size = offset + count;
 	if (rw == WRITE && final_size <= inode->i_size) {
 		/*
- 		 * For DIO we fallocate blocks for holes, we fallocate blocks
- 		 * The fallocated extent for hole is marked as uninitialized
+ 		 * We could direct write to holes and fallocate.
+		 *
+ 		 * Allocated blocks to fill the hole are marked as uninitialized
  		 * to prevent paralel buffered read to expose the stale data
  		 * before DIO complete the data IO.
- 		 * as for previously fallocated extents, ext4 get_block
+		 *
+ 		 * As to previously fallocated extents, ext4 get_block
  		 * will just simply mark the buffer mapped but still
  		 * keep the extents uninitialized.
  		 *
- 		 * At the end of IO, the ext4 end_io callback function
- 		 * will convert those unwritten extents to written,
- 		 *
+		 * for non AIO case, we will convert those unwritten extents
+		 * to written after return back from blockdev_direct_IO.
+		 *
+		 * for async DIO, the conversion needs to be defered when
+		 * the IO is completed. The ext4 end_io callback function
+		 * will be called to take care of the conversion work.
+		 * Here for async case, we allocate an io_end structure to
+		 * hook to the iocb.
  		 */
-		iocb->private = ext4_init_io_end(inode, !is_sync_kiocb(iocb));
-		if (!iocb->private)
-			return -ENOMEM;
+		iocb->private = NULL;
+		EXT4_I(inode)->cur_aio_dio = NULL;
+		if (!is_sync_kiocb(iocb)) {
+			iocb->private = ext4_init_io_end(inode);
+			if (!iocb->private)
+				return -ENOMEM;
+			/*
+			 * we save the io structure for current async
+			 * direct IO, so that later ext4_get_blocks()
+			 * could flag the io structure whether there
+			 * is a unwritten extents needs to be converted
+			 * when IO is completed.
+			 */
+			EXT4_I(inode)->cur_aio_dio = iocb->private;
+		}
+
 		ret = blockdev_direct_IO(rw, iocb, inode,
 					 inode->i_sb->s_bdev, iov,
 					 offset, nr_segs,
 					 ext4_get_block_dio_write,
 					 ext4_end_io_dio);
+		if (iocb->private)
+			EXT4_I(inode)->cur_aio_dio = NULL;
+		/*
+		 * The io_end structure takes a reference to the inode,
+		 * that structure needs to be destroyed and the
+		 * reference to the inode need to be dropped, when IO is
+		 * complete, even with 0 byte write, or failed.
+		 *
+		 * In the successful AIO DIO case, the io_end structure will be
+		 * desctroyed and the reference to the inode will be dropped
+		 * after the end_io call back function is called.
+		 *
+		 * In the case there is 0 byte write, or error case, since
+		 * VFS direct IO won't invoke the end_io call back function,
+		 * we need to free the end_io structure here.
+		 */
+		if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {
+			ext4_free_io_end(iocb->private);
+			iocb->private = NULL;
+		} else if (ret > 0)
+			/*
+			 * for non AIO case, since the IO is already
+			 * completed, we could do the convertion right here
+			 */
+			ret = ext4_convert_unwritten_extents(inode,
+								offset, ret);
 		return ret;
 	}
+
+	/* for write the the end of file case, we fall back to old way */
 	return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
 }
 
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 1a03ea9..f095c60 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -687,6 +687,8 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
 	ei->i_allocated_meta_blocks = 0;
 	ei->i_delalloc_reserved_flag = 0;
 	spin_lock_init(&(ei->i_block_reservation_lock));
+	INIT_LIST_HEAD(&ei->i_aio_dio_complete_list);
+	ei->cur_aio_dio = NULL;
 
 	return &ei->vfs_inode;
 }
@@ -3375,11 +3377,13 @@ static int ext4_sync_fs(struct super_block *sb, int wait)
 {
 	int ret = 0;
 	tid_t target;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
 
 	trace_ext4_sync_fs(sb, wait);
-	if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
+	flush_workqueue(sbi->dio_unwritten_wq);
+	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
 		if (wait)
-			jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
+			jbd2_log_wait_commit(sbi->s_journal, target);
 	}
 	return ret;
 }