Linux 3.11: Adapt to d_count changes

In preparation for upcoming changes in the 3.12 cycle, d_lockref
was introduced late in the 3.11 cycle.  The dentry's d_lock and
d_count are moved to this new structure.  A new d_lock macro makes
the change transparent for locking, but direct users of d_count
must adapt.  A new d_count() helper function is provided and
should now be used.

Use the new d_count() helper function if available, and move
some of the ifdef logic into a helper compatibility function.

Change-Id: I32a21a174d763fb7df8f1e04da3bb7260684571d
Reviewed-on: http://gerrit.openafs.org/10219
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>
Reviewed-by: Simon Wilkinson <simonxwilkinson@gmail.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>

diff --git a/acinclude.m4 b/acinclude.m4
index 15b5ad8..800333b 100644 (file)
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -897,6 +897,9 @@ case $AFS_SYSNAME in *_linux* | *_umlinux*)
                 AC_CHECK_LINUX_FUNC([d_alloc_anon],
                                     [#include <linux/fs.h>],
                                     [d_alloc_anon(NULL);])
+                AC_CHECK_LINUX_FUNC([d_count],
+                                    [#include <linux/dcache.h>],
+                                    [d_count(NULL);])
                 AC_CHECK_LINUX_FUNC([d_make_root],
                                     [#include <linux/fs.h>],
                                     [d_make_root(NULL);])

diff --git a/src/afs/LINUX/osi_compat.h b/src/afs/LINUX/osi_compat.h
index ce9178e..fdddf59 100644 (file)
--- a/src/afs/LINUX/osi_compat.h
+++ b/src/afs/LINUX/osi_compat.h
@@ -608,4 +608,32 @@ afs_proc_create(char *name, umode_t mode, struct proc_dir_entry *parent, struct
 #endif
 }
 
+static inline int
+afs_dentry_count(struct dentry *dp)
+{
+#if defined(HAVE_LINUX_D_COUNT)
+    return d_count(dp);
+#elif defined(D_COUNT_INT)
+    return dp->d_count;
+#else
+    return atomic_read(&dp->d_count);
+#endif
+}
+
+static inline void
+afs_maybe_shrink_dcache(struct dentry *dp)
+{
+#if defined(HAVE_LINUX_D_COUNT) || defined(D_COUNT_INT)
+    spin_lock(&dp->d_lock);
+    if (afs_dentry_count(dp) > 1) {
+       spin_unlock(&dp->d_lock);
+       shrink_dcache_parent(dp);
+    } else
+       spin_unlock(&dp->d_lock);
+#else
+    if (afs_dentry_count(dp) > 1)
+       shrink_dcache_parent(dp);
+#endif
+}
+
 #endif /* AFS_LINUX_OSI_COMPAT_H */

diff --git a/src/afs/LINUX/osi_vnodeops.c b/src/afs/LINUX/osi_vnodeops.c
index e9191ae..a60027e 100644 (file)
--- a/src/afs/LINUX/osi_vnodeops.c
+++ b/src/afs/LINUX/osi_vnodeops.c
@@ -1684,17 +1684,7 @@ afs_linux_rename(struct inode *oldip, struct dentry *olddp,
        rehash = newdp;
     }
 
-#if defined(D_COUNT_INT)
-    spin_lock(&olddp->d_lock);
-    if (olddp->d_count > 1) {
-       spin_unlock(&olddp->d_lock);
-       shrink_dcache_parent(olddp);
-    } else
-       spin_unlock(&olddp->d_lock);
-#else
-    if (atomic_read(&olddp->d_count) > 1)
-       shrink_dcache_parent(olddp);
-#endif
+    afs_maybe_shrink_dcache(olddp);
 
     AFS_GLOCK();
     code = afs_rename(VTOAFS(oldip), (char *)oldname, VTOAFS(newip), (char *)newname, credp);