ext4: check return value of blkdev_issue_flush()

    
blkdev_issue_flush() can fail; make sure the error gets properly
propagated.
    
This is a port of the equivalent ext3 patch from commit 44f4f729e7a1.
    
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 6 insertions, 3 deletions

diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index 2a1dcea4f12e..323eb15c2d94 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -203,7 +203,7 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
         struct inode *inode = file->f_mapping->host;
         struct ext4_inode_info *ei = EXT4_I(inode);
         journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
-        int ret;
+        int ret, err;
         tid_t commit_tid;
         bool needs_barrier = false;
 
@@ -255,8 +255,11 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
                 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);
+        if (needs_barrier) {
+                err = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
+                if (!ret)
+                        ret = err;
+        }
  out:
         mutex_unlock(&inode->i_mutex);
         trace_ext4_sync_file_exit(inode, ret);