fs/fs-writeback.c: inode writeback list tracking tracepoints
The per-sb inode writeback list tracks inodes currently under writeback
to facilitate efficient sync processing. In particular, it ensures that
sync only needs to walk through a list of inodes that were cleaned by
the sync.
Add a couple tracepoints to help identify when inodes are added/removed
to and from the writeback lists. Piggyback off of the writeback
lazytime tracepoint template as it already tracks the relevant inode
information.
Link: http://lkml.kernel.org/r/1466594593-6757-3-git-send-email-bfoster@redhat.com
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <dchinner@redhat.com>
cc: Josef Bacik <jbacik@fb.com>
Cc: Holger Hoffstätte <holger.hoffstaette@applied-asynchrony.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 1fcce834..6f9c9f6 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -990,8 +990,10 @@
if (list_empty(&inode->i_wb_list)) {
spin_lock_irqsave(&sb->s_inode_wblist_lock, flags);
- if (list_empty(&inode->i_wb_list))
+ if (list_empty(&inode->i_wb_list)) {
list_add_tail(&inode->i_wb_list, &sb->s_inodes_wb);
+ trace_sb_mark_inode_writeback(inode);
+ }
spin_unlock_irqrestore(&sb->s_inode_wblist_lock, flags);
}
}
@@ -1006,7 +1008,10 @@
if (!list_empty(&inode->i_wb_list)) {
spin_lock_irqsave(&sb->s_inode_wblist_lock, flags);
- list_del_init(&inode->i_wb_list);
+ if (!list_empty(&inode->i_wb_list)) {
+ list_del_init(&inode->i_wb_list);
+ trace_sb_clear_inode_writeback(inode);
+ }
spin_unlock_irqrestore(&sb->s_inode_wblist_lock, flags);
}
}