From efceab1d563153a2b1a6e7d35376241a48126989 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Tue, 24 Aug 2010 11:44:56 +1000 Subject: xfs: handle negative wbc->nr_to_write during sync writeback During data integrity (WB_SYNC_ALL) writeback, wbc->nr_to_write will go negative on inodes with more than 1024 dirty pages due to implementation details of write_cache_pages(). Currently XFS will abort page clustering in writeback once nr_to_write drops below zero, and so for data integrity writeback we will do very inefficient page at a time allocation and IO submission for inodes with large numbers of dirty pages. Fix this by only aborting the page clustering code when wbc->nr_to_write is negative and the sync mode is WB_SYNC_NONE. Cc: Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig --- fs/xfs/linux-2.6/xfs_aops.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/xfs/linux-2.6/xfs_aops.c') diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c index 15412fe15c3a..528be1ba1402 100644 --- a/fs/xfs/linux-2.6/xfs_aops.c +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -852,8 +852,8 @@ xfs_convert_page( SetPageUptodate(page); if (count) { - wbc->nr_to_write--; - if (wbc->nr_to_write <= 0) + if (--wbc->nr_to_write <= 0 && + wbc->sync_mode == WB_SYNC_NONE) done = 1; } xfs_start_page_writeback(page, !page_dirty, count); -- cgit v1.2.3 From b5420f235953448eeae615b3361584dc5e414f34 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 24 Aug 2010 11:47:51 +1000 Subject: xfs: do not discard page cache data on EAGAIN If xfs_map_blocks returns EAGAIN because of lock contention we must redirty the page and not disard the pagecache content and return an error from writepage. We used to do this correctly, but the logic got lost during the recent reshuffle of the writepage code. Signed-off-by: Christoph Hellwig Reported-by: Mike Gao Tested-by: Mike Gao Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- fs/xfs/linux-2.6/xfs_aops.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'fs/xfs/linux-2.6/xfs_aops.c') diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c index 528be1ba1402..b552f816de15 100644 --- a/fs/xfs/linux-2.6/xfs_aops.c +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -1068,7 +1068,7 @@ xfs_vm_writepage( * by themselves. */ if ((current->flags & (PF_MEMALLOC|PF_KSWAPD)) == PF_MEMALLOC) - goto out_fail; + goto redirty; /* * We need a transaction if there are delalloc or unwritten buffers @@ -1080,7 +1080,7 @@ xfs_vm_writepage( */ xfs_count_page_state(page, &delalloc, &unwritten); if ((current->flags & PF_FSTRANS) && (delalloc || unwritten)) - goto out_fail; + goto redirty; /* Is this page beyond the end of the file? */ offset = i_size_read(inode); @@ -1245,12 +1245,15 @@ error: if (iohead) xfs_cancel_ioend(iohead); + if (err == -EAGAIN) + goto redirty; + xfs_aops_discard_page(page); ClearPageUptodate(page); unlock_page(page); return err; -out_fail: +redirty: redirty_page_for_writepage(wbc, page); unlock_page(page); return 0; -- cgit v1.2.3