fs: move i_sb_list out from under inode_lock
Protect the per-sb inode list with a new global lock
inode_sb_list_lock and use it to protect the list manipulations and
traversals. This lock replaces the inode_lock as the inodes on the
list can be validity checked while holding the inode->i_lock and
hence the inode_lock is no longer needed to protect the list.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/inode.c b/fs/inode.c
index 389f5a2..785b1ab 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -34,10 +34,15 @@
* inode->i_state, inode->i_hash, __iget()
* inode_lru_lock protects:
* inode_lru, inode->i_lru
+ * inode_sb_list_lock protects:
+ * sb->s_inodes, inode->i_sb_list
*
* Lock ordering:
* inode_lock
* inode->i_lock
+ *
+ * inode_sb_list_lock
+ * inode->i_lock
* inode_lru_lock
*/
@@ -99,6 +104,8 @@
*/
DEFINE_SPINLOCK(inode_lock);
+__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock);
+
/*
* iprune_sem provides exclusion between the icache shrinking and the
* umount path.
@@ -378,26 +385,23 @@
spin_unlock(&inode_lru_lock);
}
-static inline void __inode_sb_list_add(struct inode *inode)
-{
- list_add(&inode->i_sb_list, &inode->i_sb->s_inodes);
-}
-
/**
* inode_sb_list_add - add inode to the superblock list of inodes
* @inode: inode to add
*/
void inode_sb_list_add(struct inode *inode)
{
- spin_lock(&inode_lock);
- __inode_sb_list_add(inode);
- spin_unlock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
+ list_add(&inode->i_sb_list, &inode->i_sb->s_inodes);
+ spin_unlock(&inode_sb_list_lock);
}
EXPORT_SYMBOL_GPL(inode_sb_list_add);
-static inline void __inode_sb_list_del(struct inode *inode)
+static inline void inode_sb_list_del(struct inode *inode)
{
+ spin_lock(&inode_sb_list_lock);
list_del_init(&inode->i_sb_list);
+ spin_unlock(&inode_sb_list_lock);
}
static unsigned long hash(struct super_block *sb, unsigned long hashval)
@@ -481,9 +485,10 @@
spin_lock(&inode_lock);
list_del_init(&inode->i_wb_list);
- __inode_sb_list_del(inode);
spin_unlock(&inode_lock);
+ inode_sb_list_del(inode);
+
if (op->evict_inode) {
op->evict_inode(inode);
} else {
@@ -539,7 +544,7 @@
struct inode *inode, *next;
LIST_HEAD(dispose);
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) {
if (atomic_read(&inode->i_count))
continue;
@@ -555,7 +560,7 @@
spin_unlock(&inode->i_lock);
list_add(&inode->i_lru, &dispose);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
dispose_list(&dispose);
@@ -584,7 +589,7 @@
struct inode *inode, *next;
LIST_HEAD(dispose);
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) {
spin_lock(&inode->i_lock);
if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) {
@@ -607,7 +612,7 @@
spin_unlock(&inode->i_lock);
list_add(&inode->i_lru, &dispose);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
dispose_list(&dispose);
@@ -867,16 +872,14 @@
{
struct inode *inode;
- spin_lock_prefetch(&inode_lock);
+ spin_lock_prefetch(&inode_sb_list_lock);
inode = alloc_inode(sb);
if (inode) {
- spin_lock(&inode_lock);
spin_lock(&inode->i_lock);
inode->i_state = 0;
spin_unlock(&inode->i_lock);
- __inode_sb_list_add(inode);
- spin_unlock(&inode_lock);
+ inode_sb_list_add(inode);
}
return inode;
}
@@ -945,7 +948,7 @@
inode->i_state = I_NEW;
hlist_add_head(&inode->i_hash, head);
spin_unlock(&inode->i_lock);
- __inode_sb_list_add(inode);
+ inode_sb_list_add(inode);
spin_unlock(&inode_lock);
/* Return the locked inode with I_NEW set, the
@@ -994,7 +997,7 @@
inode->i_state = I_NEW;
hlist_add_head(&inode->i_hash, head);
spin_unlock(&inode->i_lock);
- __inode_sb_list_add(inode);
+ inode_sb_list_add(inode);
spin_unlock(&inode_lock);
/* Return the locked inode with I_NEW set, the