From cb9bd1159c5fe8995e151fa7df10fa19f8c119cc Mon Sep 17 00:00:00 2001 From: Wu Fengguang Date: Wed, 21 Jul 2010 22:50:57 -0600 Subject: [PATCH] writeback: introduce writeback_control.inodes_written The flusher works on dirty inodes in batches, and may quit prematurely if the batch of inodes happen to be metadata-only dirtied: in this case wbc->nr_to_write won't be decreased at all, which stands for "no pages written" but also mis-interpreted as "no progress". So introduce writeback_control.inodes_written to count the inodes get cleaned from VFS POV. A non-zero value means there are some progress on writeback, in which case more writeback can be tried. Acked-by: Jan Kara Acked-by: Mel Gorman Signed-off-by: Wu Fengguang --- fs/fs-writeback.c | 4 ++++ include/linux/writeback.h | 1 + 2 files changed, 5 insertions(+) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index fe190a8..e450429 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -464,6 +464,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) * No need to add it back to the LRU. */ list_del_init(&inode->i_wb_list); + wbc->inodes_written++; } } inode_sync_complete(inode); @@ -725,6 +726,7 @@ static long wb_writeback(struct bdi_writeback *wb, wbc.more_io = 0; wbc.nr_to_write = write_chunk; wbc.pages_skipped = 0; + wbc.inodes_written = 0; trace_wbc_writeback_start(&wbc, wb->bdi); if (work->sb) @@ -741,6 +743,8 @@ static long wb_writeback(struct bdi_writeback *wb, */ if (wbc.nr_to_write <= 0) continue; + if (wbc.inodes_written) + continue; /* * Didn't write everything and we don't have more IO, bail */ diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 3f6542c..7df9026 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -34,6 +34,7 @@ struct writeback_control { long nr_to_write; /* Write this many pages, and decrement this for each page written */ long pages_skipped; /* Pages which were not written */ + long inodes_written; /* # of inodes written (at least) */ /* * For a_ops->writepages(): is start or end are non-zero then this is -- 2.7.4