Jan Kara's description for this patch is much better than mine, so I'm quoting it verbatim here: DAX currently doesn't set errors in the mapping when cache flushing fails in dax_writeback_mapping_range(). Since this function can get called only from fsync(2) or sync(2), this is actually as good as it can currently get since we correctly propagate the error up from dax_writeback_mapping_range() to filemap_fdatawrite() However, in the future better writeback error handling will enable us to properly report these errors on fsync(2) even if there are multiple file descriptors open against the file or if sync(2) gets called before fsync(2). So convert DAX to using standard error reporting through the mapping. Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Reviewed-and-Tested-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> --- fs/dax.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/dax.c b/fs/dax.c index 9899f07acf72..c663e8cc2a76 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -856,8 +856,10 @@ int dax_writeback_mapping_range(struct address_space *mapping, ret = dax_writeback_one(bdev, dax_dev, mapping, indices[i], pvec.pages[i]); - if (ret < 0) + if (ret < 0) { + mapping_set_error(mapping, ret); goto out; + } } } out: -- 2.13.0