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/drop_caches.c b/fs/drop_caches.c
index 6c6f73b..98b77c8 100644
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -8,6 +8,7 @@
#include <linux/writeback.h>
#include <linux/sysctl.h>
#include <linux/gfp.h>
+#include "internal.h"
/* A global variable is a bit ugly, but it keeps the code simple */
int sysctl_drop_caches;
@@ -16,7 +17,7 @@
{
struct inode *inode, *toput_inode = NULL;
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
spin_lock(&inode->i_lock);
if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
@@ -26,13 +27,13 @@
}
__iget(inode);
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
invalidate_mapping_pages(inode->i_mapping, 0, -1);
iput(toput_inode);
toput_inode = inode;
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
iput(toput_inode);
}