Commit d95b7aaf authored Dec 16, 2010 by Dave Chinner Committed by Dave Chinner Dec 16, 2010

xfs: rcu free inodes



Introduce RCU freeing of XFS inodes so that we can convert lookup
traversals to use rcu_read_lock() protection. This patch only
introduces the RCU freeing to minimise the potential conflicts with
mainline if this is merged into mainline via a VFS patchset. It
abuses the i_dentry list for the RCU callback structure because the
VFS patches make this a union so it is safe to use like this and
simplifies and merge issues.

This patch uses basic RCU freeing rather than SLAB_DESTROY_BY_RCU.
The later lookup patches need the same "found free inode" protection
regardless of the RCU freeing method used, so once again the RCU
freeing method can be dealt with apprpriately at merge time without
affecting any other code.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

parent 6e857567

fs/xfs/xfs_iget.c

+13 −1

Original line number	Diff line number	Diff line
		@@ -104,6 +104,18 @@ xfs_inode_alloc(
		return ip;
		}

		void
		__xfs_inode_free(
		struct rcu_head *head)
		{
		struct inode inode = container_of((void )head,
		struct inode, i_dentry);
		struct xfs_inode *ip = XFS_I(inode);

		INIT_LIST_HEAD(&inode->i_dentry);
		kmem_zone_free(xfs_inode_zone, ip);
		}

		void
		xfs_inode_free(
		struct xfs_inode *ip)
		@@ -147,7 +159,7 @@ xfs_inode_free(
		ASSERT(!spin_is_locked(&ip->i_flags_lock));
		ASSERT(completion_done(&ip->i_flush));

		kmem_zone_free(xfs_inode_zone, ip);
		call_rcu((struct rcu_head *)&VFS_I(ip)->i_dentry, __xfs_inode_free);
		}

		/*

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