[patch 45/52] fs: icache RCU hash lookups

npiggin
2010-06-24T03:16:43Z

[-- Attachment #1: fs-inode-hash-rcu.patch --]
[-- Type: text/plain, Size: 2029 bytes --]

Signed-off-by: Nick Piggin <npiggin@suse.de>
---
fs/inode.c | 38 ++++++++++++++++++++------------------
1 file changed, 20 insertions(+), 18 deletions(-)

Index: linux-2.6/fs/inode.c
===================================================================
--- linux-2.6.orig/fs/inode.c
+++ linux-2.6/fs/inode.c
@@ -603,27 +603,27 @@ static struct inode *find_inode(struct s
struct inode *inode = NULL;

repeat:
- spin_lock_bucket(b);
- hlist_bl_for_each_entry(inode, node, &b->head, i_hash) {
+ rcu_read_lock();
+ hlist_bl_for_each_entry_rcu(inode, node, &b->head, i_hash) {
if (inode->i_sb != sb)
continue;
- if (!spin_trylock(&inode->i_lock)) {
- spin_unlock_bucket(b);
- cpu_relax();
- goto repeat;
+ spin_lock(&inode->i_lock);
+ if (hlist_bl_unhashed(&inode->i_hash)) {
+ spin_unlock(&inode->i_lock);
+ continue;
}
if (!test(inode, data)) {
spin_unlock(&inode->i_lock);
continue;
}
if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) {
- spin_unlock_bucket(b);
+ rcu_read_unlock();
__wait_on_freeing_inode(inode);
goto repeat;
}
break;
}
- spin_unlock_bucket(b);
+ rcu_read_unlock();
return node ? inode : NULL;
}

@@ -639,25 +639,25 @@ static struct inode *find_inode_fast(str
struct inode *inode = NULL;

repeat:
- spin_lock_bucket(b);
- hlist_bl_for_each_entry(inode, node, &b->head, i_hash) {
+ rcu_read_lock();
+ hlist_bl_for_each_entry_rcu(inode, node, &b->head, i_hash) {
if (inode->i_ino != ino)
continue;
if (inode->i_sb != sb)
continue;
- if (!spin_trylock(&inode->i_lock)) {
- spin_unlock_bucket(b);
- cpu_relax();
- goto repeat;
+ spin_lock(&inode->i_lock);
+ if (hlist_bl_unhashed(&inode->i_hash)) {
+ spin_unlock(&inode->i_lock);
+ continue;
}
if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) {
- spin_unlock_bucket(b);
+ rcu_read_unlock();
__wait_on_freeing_inode(inode);
goto repeat;
}
break;
}
- spin_unlock_bucket(b);
+ rcu_read_unlock();
return node ? inode : NULL;
}