On Wed, May 31, 2017 at 08:45:31AM -0400, Jeff Layton wrote: > Jan's description for this patch is much better than mine, so I'm > quoting it verbatim here: > > -----------------8<----------------- > 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. > -----------------8<----------------- > > For now, only do this when the FS_WB_ERRSEQ flag is set. The > AS_EIO/AS_ENOSPC flags are not currently cleared in the older code when > writeback initiation fails, only when we discover an error after waiting > on writeback to complete, so we only want to do this with errseq_t based > error handling to prevent seeing duplicate errors on fsync. > > 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> Re-tested this version of the series with some injected DAX errors, and it looks good.
