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/quota/dquot.c b/fs/quota/dquot.c
index a1470fd..fcc8ae7 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -76,7 +76,7 @@
#include <linux/buffer_head.h>
#include <linux/capability.h>
#include <linux/quotaops.h>
-#include <linux/writeback.h> /* for inode_lock, oddly enough.. */
+#include "../internal.h" /* ugh */
#include <asm/uaccess.h>
@@ -900,7 +900,7 @@
int reserved = 0;
#endif
- 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)) ||
@@ -915,19 +915,23 @@
#endif
__iget(inode);
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
iput(old_inode);
__dquot_initialize(inode, type);
- /* We hold a reference to 'inode' so it couldn't have been
- * removed from s_inodes list while we dropped the inode_lock.
- * We cannot iput the inode now as we can be holding the last
- * reference and we cannot iput it under inode_lock. So we
- * keep the reference and iput it later. */
+
+ /*
+ * We hold a reference to 'inode' so it couldn't have been
+ * removed from s_inodes list while we dropped the
+ * inode_sb_list_lock We cannot iput the inode now as we can be
+ * holding the last reference and we cannot iput it under
+ * inode_sb_list_lock. So we keep the reference and iput it
+ * later.
+ */
old_inode = inode;
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
iput(old_inode);
#ifdef CONFIG_QUOTA_DEBUG
@@ -1008,7 +1012,7 @@
struct inode *inode;
int reserved = 0;
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
/*
* We have to scan also I_NEW inodes because they can already
@@ -1022,7 +1026,7 @@
remove_inode_dquot_ref(inode, type, tofree_head);
}
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
#ifdef CONFIG_QUOTA_DEBUG
if (reserved) {
printk(KERN_WARNING "VFS (%s): Writes happened after quota"