From e2c7617ae36b27f97643bfa08aabe27e630c1a76 Mon Sep 17 00:00:00 2001 From: Andreas Rohner Date: Mon, 13 Oct 2014 15:53:20 -0700 Subject: nilfs2: add missing blkdev_issue_flush() to nilfs_sync_fs() Under normal circumstances nilfs_sync_fs() writes out the super block, which causes a flush of the underlying block device. But this depends on the THE_NILFS_SB_DIRTY flag, which is only set if the pointer to the last segment crosses a segment boundary. So if only a small amount of data is written before the call to nilfs_sync_fs(), no flush of the block device occurs. In the above case an additional call to blkdev_issue_flush() is needed. To prevent unnecessary overhead, the new flag nilfs->ns_flushed_device is introduced, which is cleared whenever new logs are written and set whenever the block device is flushed. For convenience the function nilfs_flush_device() is added, which contains the above logic. Signed-off-by: Andreas Rohner Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nilfs2/super.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'fs/nilfs2/super.c') diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index 228f5bdf0772..2e5b3ec85b8f 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -310,6 +310,9 @@ int nilfs_commit_super(struct super_block *sb, int flag) nilfs->ns_sbsize)); } clear_nilfs_sb_dirty(nilfs); + nilfs->ns_flushed_device = 1; + /* make sure store to ns_flushed_device cannot be reordered */ + smp_wmb(); return nilfs_sync_super(sb, flag); } @@ -514,6 +517,9 @@ static int nilfs_sync_fs(struct super_block *sb, int wait) } up_write(&nilfs->ns_sem); + if (!err) + err = nilfs_flush_device(nilfs); + return err; } -- cgit v1.2.3-59-g8ed1b