| Message ID | 20170525104746.8032-1-jlayton@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, May 25, 2017 at 06:47:46AM -0400, Jeff Layton wrote: > Jan'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@redhat.com> > Reviewed-by: Jan Kara <jack@suse.cz> > Reviewed-by: Christoph Hellwig <hch@lst.de> > Reviewed-and-Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com> Is this still part of a larger series, or are you trying to submit it on its own? On it's own this patch still suffers from the issue I reported here: https://lkml.org/lkml/2017/3/6/976 > --- > fs/dax.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/fs/dax.c b/fs/dax.c > index c22eaf162f95..441280e15d5b 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: > -- > 2.9.4 >
On Fri, 2017-05-26 at 14:31 -0600, Ross Zwisler wrote: > On Thu, May 25, 2017 at 06:47:46AM -0400, Jeff Layton wrote: > > Jan'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@redhat.com> > > Reviewed-by: Jan Kara <jack@suse.cz> > > Reviewed-by: Christoph Hellwig <hch@lst.de> > > Reviewed-and-Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com> > > Is this still part of a larger series, or are you trying to submit it on its > own? I was trying to submit it on its own. Trying to get a series merged that sprawls over the tree like this is proving difficult, so I was hoping to get maintainers to pick up individual patches for their subsystems. > On it's own this patch still suffers from the issue I reported here: > > https://lkml.org/lkml/2017/3/6/976 > My bad. I remember seeing you mail this and then let it slip through the cracks. Let's see, you said: > I think maybe the missing piece is that our normal DAX fsync call stack > doesn't include a call to filemap_check_errors() if we return -EIO. I think the actual problem is in filemap_write_and_wait_range. When there is an error from __filemap_fdatawrite_range, we probably ought to go ahead and clear the AS_EIO/AS_ENOSPC flags as well even though we're not waiting on writeback. I think I had a patch to do that in an earlier iteration of this series, but I dropped it when I started pursuing the errseq_t based error tracking. Now that we're going to have to do this in a more piecemeal way, it may be worth resurrecting that patch as an interim step before merging this one. I'll see if I can dust that patch off after the holiday weekend. Thanks,
diff --git a/fs/dax.c b/fs/dax.c index c22eaf162f95..441280e15d5b 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: