fs: move i_wb_list out from under inode_lock
Protect the inode writeback list with a new global lock
inode_wb_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 785b1ab..239fdc0 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -26,6 +26,7 @@
#include <linux/posix_acl.h>
#include <linux/ima.h>
#include <linux/cred.h>
+#include "internal.h"
/*
* inode locking rules.
@@ -36,6 +37,8 @@
* inode_lru, inode->i_lru
* inode_sb_list_lock protects:
* sb->s_inodes, inode->i_sb_list
+ * inode_wb_list_lock protects:
+ * bdi->wb.b_{dirty,io,more_io}, inode->i_wb_list
*
* Lock ordering:
* inode_lock
@@ -44,6 +47,9 @@
* inode_sb_list_lock
* inode->i_lock
* inode_lru_lock
+ *
+ * inode_wb_list_lock
+ * inode->i_lock
*/
/*
@@ -105,6 +111,7 @@
DEFINE_SPINLOCK(inode_lock);
__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock);
+__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_wb_list_lock);
/*
* iprune_sem provides exclusion between the icache shrinking and the
@@ -483,10 +490,7 @@
BUG_ON(!(inode->i_state & I_FREEING));
BUG_ON(!list_empty(&inode->i_lru));
- spin_lock(&inode_lock);
- list_del_init(&inode->i_wb_list);
- spin_unlock(&inode_lock);
-
+ inode_wb_list_del(inode);
inode_sb_list_del(inode);
if (op->evict_inode) {