[REVIEW 3 of 4] Fix recalim handling in xfs_iget_core

David Chinner
2006-10-24T07:21:53Z

--
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);