On Wed, Oct 02, 2013 at 09:38:43PM +0400, Maxim Patlasov wrote: > BDI_WRITTEN counter is used to estimate bdi bandwidth. It must be incremented > every time as bdi ends page writeback. No matter whether it was fulfilled by > actual write or by discarding the request (e.g. due to shrunk i_size). > > Note that even before writepages patches, the case "Got truncated off > completely" was handled in fuse_send_writepage() by calling > fuse_writepage_finish() which updated BDI_WRITTEN unconditionally.
Hmm, I'm not sure I can agree with this. If BDI_WRITTEN is used for bandwidth estimation, then I think it's more correct not to count rewrites and truncated pages. But I don't see this matter either way since this is just used as a heuristic and the occasional extra or lack of count shouldn't make a significant difference. Thanks, Miklos > > Signed-off-by: Maxim Patlasov <[email protected]> > --- > fs/fuse/file.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/fs/fuse/file.c b/fs/fuse/file.c > index a3c7123..5d323bd 100644 > --- a/fs/fuse/file.c > +++ b/fs/fuse/file.c > @@ -1536,6 +1536,7 @@ static void fuse_writepage_end(struct fuse_conn *fc, > struct fuse_req *req) > drop->inode->i_mapping->backing_dev_info; > dec_bdi_stat(bdi, BDI_WRITEBACK); > dec_zone_page_state(drop->pages[0], NR_WRITEBACK_TEMP); > + bdi_writeout_inc(bdi); > fuse_writepage_free(fc, drop); > fuse_put_request(fc, drop); > drop = next; > @@ -1706,11 +1707,14 @@ static bool fuse_writepage_in_flight(struct fuse_req > *new_req, > > if (old_req->num_pages == 1 && (old_req->state == FUSE_REQ_INIT || > old_req->state == FUSE_REQ_PENDING)) { > + struct backing_dev_info *bdi = page->mapping->backing_dev_info; > + > copy_highpage(old_req->pages[0], page); > spin_unlock(&fc->lock); > > - dec_bdi_stat(page->mapping->backing_dev_info, BDI_WRITEBACK); > + dec_bdi_stat(bdi, BDI_WRITEBACK); > dec_zone_page_state(page, NR_WRITEBACK_TEMP); > + bdi_writeout_inc(bdi); > fuse_writepage_free(fc, new_req); > fuse_request_free(new_req); > goto out; > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
