From 98474236f72e5a8b89c14cd7c74f0bb77a4b1a99 Mon Sep 17 00:00:00 2001 From: Waiman Long Date: Wed, 28 Aug 2013 18:24:59 -0700 Subject: vfs: make the dentry cache use the lockref infrastructure This just replaces the dentry count/lock combination with the lockref structure that contains both a count and a spinlock, and does the mechanical conversion to use the lockref infrastructure. There are no semantic changes here, it's purely syntactic. The reference lockref implementation uses the spinlock exactly the same way that the old dcache code did, and the bulk of this patch is just expanding the internal "d_count" use in the dcache code to use "d_lockref.count" instead. This is purely preparation for the real change to make the reference count updates be lockless during the 3.12 merge window. [ As with the previous commit, this is a rewritten version of a concept originally from Waiman, so credit goes to him, blame for any errors goes to me. Waiman's patch had some semantic differences for taking advantage of the lockless update in dget_parent(), while this patch is intentionally a pure search-and-replace change with no semantic changes. - Linus ] Signed-off-by: Waiman Long Signed-off-by: Linus Torvalds --- fs/namei.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'fs/namei.c') diff --git a/fs/namei.c b/fs/namei.c index 8b61d103a8a7..7720fbd5277b 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -536,8 +536,8 @@ static int unlazy_walk(struct nameidata *nd, struct dentry *dentry) * a reference at this point. */ BUG_ON(!IS_ROOT(dentry) && dentry->d_parent != parent); - BUG_ON(!parent->d_count); - parent->d_count++; + BUG_ON(!parent->d_lockref.count); + parent->d_lockref.count++; spin_unlock(&dentry->d_lock); } spin_unlock(&parent->d_lock); @@ -3327,7 +3327,7 @@ void dentry_unhash(struct dentry *dentry) { shrink_dcache_parent(dentry); spin_lock(&dentry->d_lock); - if (dentry->d_count == 1) + if (dentry->d_lockref.count == 1) __d_drop(dentry); spin_unlock(&dentry->d_lock); } -- cgit v1.2.3