[PATCH v5 12/17] fs: allow __generic_file_fsync to support both flavors of error reporting

[Jeff Layton]

For now, we add a FS_WB_ERRSEQ check to know how to handle it.

Signed-off-by: Jeff Layton <jlay...@redhat.com>
---
 fs/libfs.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/fs/libfs.c b/fs/libfs.c
index 1dec90819366..2ae58a252718 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -971,10 +971,18 @@ int __generic_file_fsync(struct file *file, loff_t start, 
loff_t end,
                                 int datasync)
 {
        struct inode *inode = file->f_mapping->host;
-       int err;
-       int ret;
-
-       err = filemap_write_and_wait_range(inode->i_mapping, start, end);
+       int err, ret;
+       bool use_errseq = inode->i_sb->s_type->fs_flags & FS_WB_ERRSEQ;
+       errseq_t since;
+
+       if (use_errseq) {
+               since = READ_ONCE(file->f_wb_err);
+               err = filemap_write_and_wait_range_since(inode->i_mapping,
+                               start, end, since);
+       } else {
+               err = filemap_write_and_wait_range(inode->i_mapping,
+                                                       start, end);
+       }
        if (err)
                return err;
 
@@ -988,11 +996,15 @@ int __generic_file_fsync(struct file *file, loff_t start, 
loff_t end,
        err = sync_inode_metadata(inode, 1);
        if (ret == 0)
                ret = err;
-
 out:
        inode_unlock(inode);
-       err = filemap_check_errors(inode->i_mapping);
-       return ret ? ret : err;
+       if (ret == 0) {
+               if (use_errseq)
+                       err = filemap_check_wb_err(inode->i_mapping, since);
+               else
+                       err = filemap_check_errors(inode->i_mapping);
+       }
+       return ret;
 }
 EXPORT_SYMBOL(__generic_file_fsync);
 
-- 
2.9.4