[XFS] Combine the XFS and Linux inodes

To avoid issues with different lifecycles of XFS and Linux inodes, embedd
the linux inode inside the XFS inode. This means that the linux inode has
the same lifecycle as the XFS inode, even when it has been released by the
OS. XFS inodes don't live much longer than this (a short stint in reclaim
at most), so there isn't significant memory usage penalties here.

Version 3 o kill xfs_icount()

Version 2 o remove unused commented out code from xfs_iget(). o kill
useless cast in VFS_I()

SGI-PV: 988141

SGI-Modid: xfs-linux-melb:xfs-kern:32323a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>

1 files changed, 13 insertions, 4 deletions

diff --git a/fs/xfs/linux-2.6/xfs_iops.c b/fs/xfs/linux-2.6/xfs_iops.c
index 3bfb3c0f8e29..37bb1012aff1 100644
--- a/fs/xfs/linux-2.6/xfs_iops.c
+++ b/fs/xfs/linux-2.6/xfs_iops.c
@@ -64,14 +64,14 @@ xfs_synchronize_atime(
 {
 	struct inode	*inode = VFS_I(ip);
 
-	if (inode) {
+	if (!(inode->i_state & I_CLEAR)) {
 		ip->i_d.di_atime.t_sec = (__int32_t)inode->i_atime.tv_sec;
 		ip->i_d.di_atime.t_nsec = (__int32_t)inode->i_atime.tv_nsec;
 	}
 }
 
 /*
- * If the linux inode exists, mark it dirty.
+ * If the linux inode is valid, mark it dirty.
  * Used when commiting a dirty inode into a transaction so that
  * the inode will get written back by the linux code
  */
@@ -81,7 +81,7 @@ xfs_mark_inode_dirty_sync(
 {
 	struct inode	*inode = VFS_I(ip);
 
-	if (inode)
+	if (!(inode->i_state & (I_WILL_FREE|I_FREEING|I_CLEAR)))
 		mark_inode_dirty_sync(inode);
 }
 
@@ -766,12 +766,21 @@ xfs_diflags_to_iflags(
  * When reading existing inodes from disk this is called directly
  * from xfs_iget, when creating a new inode it is called from
  * xfs_ialloc after setting up the inode.
+ *
+ * We are always called with an uninitialised linux inode here.
+ * We need to initialise the necessary fields and take a reference
+ * on it.
  */
 void
 xfs_setup_inode(
 	struct xfs_inode	*ip)
 {
-	struct inode		*inode = ip->i_vnode;
+	struct inode		*inode = &ip->i_vnode;
+
+	inode->i_ino = ip->i_ino;
+	inode->i_state = I_NEW|I_LOCK;
+	inode_add_to_lists(ip->i_mount->m_super, inode);
+	ASSERT(atomic_read(&inode->i_count) == 1);
 
 	inode->i_mode	= ip->i_d.di_mode;
 	inode->i_nlink	= ip->i_d.di_nlink;