[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, 32 insertions, 11 deletions

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index bc33762abc49..99d9118c4a41 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -813,6 +813,16 @@ xfs_inode_alloc(
         ASSERT(!spin_is_locked(&ip->i_flags_lock));
         ASSERT(list_empty(&ip->i_reclaim));
 
+        /*
+         * initialise the VFS inode here to get failures
+         * out of the way early.
+         */
+        if (!inode_init_always(mp->m_super, VFS_I(ip))) {
+                kmem_zone_free(xfs_inode_zone, ip);
+                return NULL;
+        }
+
+        /* initialise the xfs inode */
         ip->i_ino = ino;
         ip->i_mount = mp;
         ip->i_blkno = 0;
@@ -1086,6 +1096,7 @@ xfs_ialloc(
         uint            flags;
         int             error;
         timespec_t      tv;
+        int             filestreams = 0;
 
         /*
          * Call the space management code to pick
@@ -1093,9 +1104,8 @@ xfs_ialloc(
          */
         error = xfs_dialloc(tp, pip ? pip->i_ino : 0, mode, okalloc,
                             ialloc_context, call_again, &ino);
-        if (error != 0) {
+        if (error)
                 return error;
-        }
         if (*call_again || ino == NULLFSINO) {
                 *ipp = NULL;
                 return 0;
@@ -1109,9 +1119,8 @@ xfs_ialloc(
          */
         error = xfs_trans_iget(tp->t_mountp, tp, ino,
                                 XFS_IGET_CREATE, XFS_ILOCK_EXCL, &ip);
-        if (error != 0) {
+        if (error)
                 return error;
-        }
         ASSERT(ip != NULL);
 
         ip->i_d.di_mode = (__uint16_t)mode;
@@ -1192,13 +1201,12 @@ xfs_ialloc(
                 flags |= XFS_ILOG_DEV;
                 break;
         case S_IFREG:
-                if (pip && xfs_inode_is_filestream(pip)) {
-                        error = xfs_filestream_associate(pip, ip);
-                        if (error < 0)
-                                return -error;
-                        if (!error)
-                                xfs_iflags_set(ip, XFS_IFILESTREAM);
-                }
+                /*
+                 * we can't set up filestreams until after the VFS inode
+                 * is set up properly.
+                 */
+                if (pip && xfs_inode_is_filestream(pip))
+                        filestreams = 1;
                 /* fall through */
         case S_IFDIR:
                 if (pip && (pip->i_d.di_flags & XFS_DIFLAG_ANY)) {
@@ -1264,6 +1272,15 @@ xfs_ialloc(
         /* now that we have an i_mode we can setup inode ops and unlock */
         xfs_setup_inode(ip);
 
+        /* now we have set up the vfs inode we can associate the filestream */
+        if (filestreams) {
+                error = xfs_filestream_associate(pip, ip);
+                if (error < 0)
+                        return -error;
+                if (!error)
+                        xfs_iflags_set(ip, XFS_IFILESTREAM);
+        }
+
         *ipp = ip;
         return 0;
 }
@@ -2650,6 +2667,10 @@ xfs_idestroy_fork(
  * It must free the inode itself and any buffers allocated for
  * if_extents/if_data and if_broot.  It must also free the lock
  * associated with the inode.
+ *
+ * Note: because we don't initialise everything on reallocation out
+ * of the zone, we must ensure we nullify everything correctly before
+ * freeing the structure.
  */
 void
 xfs_idestroy(