From jlayton@redhat.com  Wed Mar 21 11:42:20 2018
From: Jeff Layton <jlayton@redhat.com>
Subject: fs: convert __generic_file_fsync to use errseq_t based reporting
Git-commit: 383aa543c2f46f245d652c0e5c77390f07ece657
Patch-mainline: v4.13-rc1
References: bsc#1086149 bsc#1086285

Many simple, block-based filesystems use generic_file_fsync as their
fsync operation. Some others (ext* and fat) also call this function
to handle syncing out data.

Switch this code over to use errseq_t based error reporting so that
all of these filesystems get reliable error reporting via fsync,
fdatasync and msync.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Jeff Mahoney <jeffm@suse.com>
---
 fs/libfs.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/fs/libfs.c b/fs/libfs.c
index 1b76f29799bf..3aabe553fc45 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -974,7 +974,7 @@ int __generic_file_fsync(struct file *file, loff_t start, loff_t end,
 	int err;
 	int ret;
 
-	err = filemap_write_and_wait_range(inode->i_mapping, start, end);
+	err = file_write_and_wait_range(file, start, end);
 	if (err)
 		return err;
 
@@ -991,9 +991,11 @@ int __generic_file_fsync(struct file *file, loff_t start, loff_t end,
 
 out:
 	inode_unlock(inode);
-	/* must call this unconditionally as it clears AS_* error flags */
-	err = filemap_check_errors(inode->i_mapping);
-	return ret ? ret : err;
+	/* check and advance again to catch errors after syncing out buffers */
+	err = file_check_and_advance_wb_err(file);
+	if (ret == 0)
+		ret = err;
+	return ret;
 }
 EXPORT_SYMBOL(__generic_file_fsync);