+
+static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate)
+{
+ ext4_io_end_t *io_end = bh->b_private;
+ struct workqueue_struct *wq;
+ struct inode *inode;
+ unsigned long flags;
+
+ if (!test_clear_buffer_uninit(bh) || !io_end)
+ goto out;
+
+ if (!(io_end->inode->i_sb->s_flags & MS_ACTIVE)) {
+ printk("sb umounted, discard end_io request for inode %lu\n",
+ io_end->inode->i_ino);
+ ext4_free_io_end(io_end);
+ goto out;
+ }
+
+ io_end->flag = EXT4_IO_UNWRITTEN;
+ inode = io_end->inode;
+
+ /* Add the io_end to per-inode completed io list*/
+ spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags);
+ list_add_tail(&io_end->list, &EXT4_I(inode)->i_completed_io_list);
+ spin_unlock_irqrestore(&EXT4_I(inode)->i_completed_io_lock, flags);
+
+ wq = EXT4_SB(inode->i_sb)->dio_unwritten_wq;
+ /* queue the work to convert unwritten extents to written */
+ queue_work(wq, &io_end->work);
+out:
+ bh->b_private = NULL;
+ bh->b_end_io = NULL;
+ clear_buffer_uninit(bh);
+ end_buffer_async_write(bh, uptodate);
+}
+
+static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode)
+{
+ ext4_io_end_t *io_end;
+ struct page *page = bh->b_page;
+ loff_t offset = (sector_t)page->index << PAGE_CACHE_SHIFT;
+ size_t size = bh->b_size;
+
+retry:
+ io_end = ext4_init_io_end(inode, GFP_ATOMIC);
+ if (!io_end) {
+ if (printk_ratelimit())
+ printk(KERN_WARNING "%s: allocation fail\n", __func__);
+ schedule();
+ goto retry;
+ }
+ io_end->offset = offset;
+ io_end->size = size;
+ /*
+ * We need to hold a reference to the page to make sure it
+ * doesn't get evicted before ext4_end_io_work() has a chance
+ * to convert the extent from written to unwritten.
+ */
+ io_end->page = page;
+ get_page(io_end->page);
+
+ bh->b_private = io_end;
+ bh->b_end_io = ext4_end_io_buffer_write;
+ return 0;
+}
+