From 357f8e658bba8a085c4a5d4331e30894be8096b8 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 7 Jan 2011 17:49:42 +1100 Subject: [PATCH] fs: dcache reduce dcache_inode_lock dcache_inode_lock can be avoided in d_delete() and d_materialise_unique() in cases where it is not required. Signed-off-by: Nick Piggin --- fs/dcache.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index ccdc5c2512df..01f016799fd4 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1828,10 +1828,15 @@ void d_delete(struct dentry * dentry) /* * Are we the only user? */ - spin_lock(&dcache_inode_lock); +again: spin_lock(&dentry->d_lock); isdir = S_ISDIR(dentry->d_inode->i_mode); if (dentry->d_count == 1) { + if (!spin_trylock(&dcache_inode_lock)) { + spin_unlock(&dentry->d_lock); + cpu_relax(); + goto again; + } dentry->d_flags &= ~DCACHE_CANT_MOUNT; dentry_iput(dentry); fsnotify_nameremove(dentry, isdir); @@ -1842,7 +1847,6 @@ void d_delete(struct dentry * dentry) __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_inode_lock); fsnotify_nameremove(dentry, isdir); } @@ -2164,14 +2168,15 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode) BUG_ON(!d_unhashed(dentry)); - spin_lock(&dcache_inode_lock); - if (!inode) { actual = dentry; __d_instantiate(dentry, NULL); - goto found_lock; + d_rehash(actual); + goto out_nolock; } + spin_lock(&dcache_inode_lock); + if (S_ISDIR(inode->i_mode)) { struct dentry *alias; @@ -2198,10 +2203,9 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode) actual = __d_instantiate_unique(dentry, inode); if (!actual) actual = dentry; - else if (unlikely(!d_unhashed(actual))) - goto shouldnt_be_hashed; + else + BUG_ON(!d_unhashed(actual)); -found_lock: spin_lock(&actual->d_lock); found: spin_lock(&dcache_hash_lock); @@ -2217,10 +2221,6 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode) iput(inode); return actual; - -shouldnt_be_hashed: - spin_unlock(&dcache_inode_lock); - BUG(); } EXPORT_SYMBOL_GPL(d_materialise_unique); -- GitLab