From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Tue, 07 Oct 2008 00:16:03 -0700 (PDT) Received: from relay.sgi.com (netops-testserver-3.corp.sgi.com [192.26.57.72]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id m977G1ko006789 for ; Tue, 7 Oct 2008 00:16:01 -0700 Message-ID: <48EB1ABD.3020503@sgi.com> Date: Tue, 07 Oct 2008 18:15:57 +1000 From: Lachlan McIlroy Reply-To: lachlan@sgi.com MIME-Version: 1.0 Subject: [PATCH V2] Re-dirty pages on ENOSPC when converting delayed allocations Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: xfs-oss , xfs-dev If we get an error in xfs_page_state_convert() - and it's not EAGAIN - then we throw away the dirty page without converting the delayed allocation. This leaves delayed allocations that can never be removed and confuses code that expects a flush of the file to clear them. We need to re-dirty the page on error so we can try again later or report that the flush failed. This change is needed to handle the condition where we are at ENOSPC and we exhaust the reserved block pool (because many transactions are executing concurrently) and calls to xfs_trans_reserve() start failing with ENOSPC errors. Version 2 wont return EAGAIN from xfs_vm_writepage() and also converts an ENOSPC error to an EAGAIN for asynchronous writeback to avoid setting an error in the inode mapping when we don't need to. --- a/fs/xfs/linux-2.6/xfs_aops.c 2008-10-07 17:02:04.000000000 +1000 +++ b/fs/xfs/linux-2.6/xfs_aops.c 2008-10-07 17:58:04.000000000 +1000 @@ -1147,16 +1147,6 @@ error: if (iohead) xfs_cancel_ioend(iohead); - /* - * If it's delalloc and we have nowhere to put it, - * throw it away, unless the lower layers told - * us to try again. - */ - if (err != -EAGAIN) { - if (!unmapped) - block_invalidatepage(page, 0); - ClearPageUptodate(page); - } return err; } @@ -1185,7 +1175,7 @@ xfs_vm_writepage( struct page *page, struct writeback_control *wbc) { - int error; + int error = 0; int need_trans; int delalloc, unmapped, unwritten; struct inode *inode = page->mapping->host; @@ -1231,19 +1221,16 @@ xfs_vm_writepage( * to real space and flush out to disk. */ error = xfs_page_state_convert(inode, page, wbc, 1, unmapped); - if (error == -EAGAIN) - goto out_fail; if (unlikely(error < 0)) - goto out_unlock; + goto out_fail; return 0; out_fail: redirty_page_for_writepage(wbc, page); unlock_page(page); - return 0; -out_unlock: - unlock_page(page); + if (error == -EAGAIN) + error = 0; return error; } --- a/fs/xfs/xfs_iomap.c 2008-10-07 17:02:04.000000000 +1000 +++ b/fs/xfs/xfs_iomap.c 2008-10-07 17:58:04.000000000 +1000 @@ -269,6 +269,8 @@ xfs_iomap( error = xfs_iomap_write_allocate(ip, offset, count, &imap, &nimaps); + if ((flags & BMAPI_TRYLOCK) && error == ENOSPC) + error = EAGAIN; break; }