1 files changed, 115 insertions, 27 deletions

diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index 592adf2e546e..ce66d2fe826c 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -34,6 +34,89 @@
 
 #include <trace/events/ext4.h>
 
+static void dump_completed_IO(struct inode * inode)
+{
+#ifdef  EXT4FS_DEBUG
+        struct list_head *cur, *before, *after;
+        ext4_io_end_t *io, *io0, *io1;
+        unsigned long flags;
+
+        if (list_empty(&EXT4_I(inode)->i_completed_io_list)){
+                ext4_debug("inode %lu completed_io list is empty\n", inode->i_ino);
+                return;
+        }
+
+        ext4_debug("Dump inode %lu completed_io list \n", inode->i_ino);
+        spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags);
+        list_for_each_entry(io, &EXT4_I(inode)->i_completed_io_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);
+        }
+        spin_unlock_irqrestore(&EXT4_I(inode)->i_completed_io_lock, flags);
+#endif
+}
+
+/*
+ * This function is called from ext4_sync_file().
+ *
+ * When 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 pending/completed IO that
+ * might needs to do the conversion. This function walks through
+ * the list and convert the related unwritten extents for completed IO
+ * to written.
+ * The function return the number of pending IOs on success.
+ */
+extern int ext4_flush_completed_IO(struct inode *inode)
+{
+        ext4_io_end_t *io;
+        struct ext4_inode_info *ei = EXT4_I(inode);
+        unsigned long flags;
+        int ret = 0;
+        int ret2 = 0;
+
+        if (list_empty(&ei->i_completed_io_list))
+                return ret;
+
+        dump_completed_IO(inode);
+        spin_lock_irqsave(&ei->i_completed_io_lock, flags);
+        while (!list_empty(&ei->i_completed_io_list)){
+                io = list_entry(ei->i_completed_io_list.next,
+                                ext4_io_end_t, list);
+                /*
+                 * Calling ext4_end_io_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
+                 * conversion finished. The io structure has a flag to
+                 * avoid double converting from both fsync and background work
+                 * queue work.
+                 */
+                spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
+                ret = ext4_end_io_nolock(io);
+                spin_lock_irqsave(&ei->i_completed_io_lock, flags);
+                if (ret < 0)
+                        ret2 = ret;
+                else
+                        list_del_init(&io->list);
+        }
+        spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
+        return (ret2 < 0) ? ret2 : 0;
+}
+
 /*
  * If we're not journaling and this is a just-created file, we have to
  * sync our parent directory (if it was freshly created) since
@@ -42,9 +125,11 @@
  * the parent directory's parent as well, and so on recursively, if
  * they are also freshly created.
  */
-static void ext4_sync_parent(struct inode *inode)
+static int ext4_sync_parent(struct inode *inode)
 {
+        struct writeback_control wbc;
         struct dentry *dentry = NULL;
+        int ret = 0;
 
         while (inode && ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) {
                 ext4_clear_inode_state(inode, EXT4_STATE_NEWENTRY);
@@ -53,8 +138,17 @@ static void ext4_sync_parent(struct inode *inode)
                 if (!dentry || !dentry->d_parent || !dentry->d_parent->d_inode)
                         break;
                 inode = dentry->d_parent->d_inode;
-                sync_mapping_buffers(inode->i_mapping);
+                ret = sync_mapping_buffers(inode->i_mapping);
+                if (ret)
+                        break;
+                memset(&wbc, 0, sizeof(wbc));
+                wbc.sync_mode = WB_SYNC_ALL;
+                wbc.nr_to_write = 0;         /* only write out the inode */
+                ret = sync_inode(inode, &wbc);
+                if (ret)
+                        break;
         }
+        return ret;
 }
 
 /*
@@ -78,23 +172,24 @@ int ext4_sync_file(struct file *file, int datasync)
         journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
         int ret;
         tid_t commit_tid;
+        bool needs_barrier = false;
 
         J_ASSERT(ext4_journal_current_handle() == NULL);
 
-        trace_ext4_sync_file(file, datasync);
+        trace_ext4_sync_file_enter(file, datasync);
 
         if (inode->i_sb->s_flags & MS_RDONLY)
                 return 0;
 
-        ret = flush_completed_IO(inode);
+        ret = ext4_flush_completed_IO(inode);
         if (ret < 0)
-                return ret;
+                goto out;
 
         if (!journal) {
                 ret = generic_file_fsync(file, datasync);
                 if (!ret && !list_empty(&inode->i_dentry))
-                        ext4_sync_parent(inode);
-                return ret;
+                        ret = ext4_sync_parent(inode);
+                goto out;
         }
 
         /*
@@ -111,27 +206,20 @@ int ext4_sync_file(struct file *file, int datasync)
          *  (they were dirtied by commit).  But that's OK - the blocks are
          *  safe in-journal, which is all fsync() needs to ensure.
          */
-        if (ext4_should_journal_data(inode))
-                return ext4_force_commit(inode->i_sb);
+        if (ext4_should_journal_data(inode)) {
+                ret = ext4_force_commit(inode->i_sb);
+                goto out;
+        }
 
         commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid;
-        if (jbd2_log_start_commit(journal, commit_tid)) {
-                /*
-                 * When the journal is on a different device than the
-                 * fs data disk, we need to issue the barrier in
-                 * writeback mode.  (In ordered mode, the jbd2 layer
-                 * will take care of issuing the barrier.  In
-                 * data=journal, all of the data blocks are written to
-                 * the journal device.)
-                 */
-                if (ext4_should_writeback_data(inode) &&
-                    (journal->j_fs_dev != journal->j_dev) &&
-                    (journal->j_flags & JBD2_BARRIER))
-                        blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL,
-                                        NULL, BLKDEV_IFL_WAIT);
-                ret = jbd2_log_wait_commit(journal, commit_tid);
-        } else if (journal->j_flags & JBD2_BARRIER)
-                blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL,
-                        BLKDEV_IFL_WAIT);
+        if (journal->j_flags & JBD2_BARRIER &&
+            !jbd2_trans_will_send_data_barrier(journal, commit_tid))
+                needs_barrier = true;
+        jbd2_log_start_commit(journal, commit_tid);
+        ret = jbd2_log_wait_commit(journal, commit_tid);
+        if (needs_barrier)
+                blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
+ out:
+        trace_ext4_sync_file_exit(inode, ret);
         return ret;
 }