inode: convert inode_sb_list_lock to per-sb
The process of reducing contention on per-superblock inode lists
starts with moving the locking to match the per-superblock inode
list. This takes the global lock out of the picture and reduces the
contention problems to within a single filesystem. This doesn't get
rid of contention as the locks still have global CPU scope, but it
does isolate operations on different superblocks form each other.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dave Chinner <dchinner@redhat.com>
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 20d1f74..2863ec6 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -923,7 +923,7 @@
int reserved = 0;
#endif
- spin_lock(&inode_sb_list_lock);
+ spin_lock(&sb->s_inode_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)) ||
@@ -934,7 +934,7 @@
}
__iget(inode);
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_sb_list_lock);
+ spin_unlock(&sb->s_inode_list_lock);
#ifdef CONFIG_QUOTA_DEBUG
if (unlikely(inode_get_rsv_space(inode) > 0))
@@ -946,15 +946,15 @@
/*
* 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
+ * s_inode_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
+ * s_inode_list_lock. So we keep the reference and iput it
* later.
*/
old_inode = inode;
- spin_lock(&inode_sb_list_lock);
+ spin_lock(&sb->s_inode_list_lock);
}
- spin_unlock(&inode_sb_list_lock);
+ spin_unlock(&sb->s_inode_list_lock);
iput(old_inode);
#ifdef CONFIG_QUOTA_DEBUG
@@ -1023,7 +1023,7 @@
struct inode *inode;
int reserved = 0;
- spin_lock(&inode_sb_list_lock);
+ spin_lock(&sb->s_inode_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
@@ -1039,7 +1039,7 @@
}
spin_unlock(&dq_data_lock);
}
- spin_unlock(&inode_sb_list_lock);
+ spin_unlock(&sb->s_inode_list_lock);
#ifdef CONFIG_QUOTA_DEBUG
if (reserved) {
printk(KERN_WARNING "VFS (%s): Writes happened after quota"