[REVIEW 3 of 4] Fix recalim handling in xfs_iget_core

[David Chinner <dgc@xxxxxxx>]

-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group


Fix the xfs_iget_core() handling of the XFS_IRECLAIMABLE flag so it
doesn't violate the guarantee we need to provide to xfs_iunpin()
w.r.t. the existence of a linux inode.

---
 fs/xfs/xfs_iget.c |   28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

Index: 2.6.x-xfs-new/fs/xfs/xfs_iget.c
===================================================================
--- 2.6.x-xfs-new.orig/fs/xfs/xfs_iget.c        2006-10-19 10:25:07.000000000 
+1000
+++ 2.6.x-xfs-new/fs/xfs/xfs_iget.c     2006-10-19 10:29:26.460972850 +1000
@@ -238,6 +238,34 @@ again:
                                        goto again;
                                }
 
+                               /*
+                                * If IRECLAIMABLE is set on this inode and 
lookup is
+                                * racing with unlink, then we should return an 
error
+                                * immediately so we don't remove it from the 
reclaim
+                                * list and potentially leak the inode.
+                                *
+                                * Also, there may be transactions sitting in 
the
+                                * incore log buffers or being flushed to disk 
at this
+                                * time.  We can't clear the XFS_IRECLAIMABLE 
flag
+                                * until these transactions have hit the disk,
+                                * otherwise we will void the guarantee the flag
+                                * provides xfs_iunpin()
+                                */
+                               if (xfs_iflags_test(ip, XFS_IRECLAIMABLE)) {
+                                       if ((ip->i_d.di_mode == 0) &&
+                                           !(flags & XFS_IGET_CREATE)) {
+                                               read_unlock(&ih->ih_lock);
+                                                       return ENOENT;
+                                       }
+                                       if (xfs_ipincount(ip)) {
+                                               read_unlock(&ih->ih_lock);
+                                               xfs_log_force(mp, 0,
+                                                       
XFS_LOG_FORCE|XFS_LOG_SYNC);
+                                               XFS_STATS_INC(xs_ig_frecycle);
+                                               goto again;
+                                       }
+                               }
+
                                vn_trace_exit(vp, "xfs_iget.alloc",
                                        (inst_t *)__return_address);