15 files changed, 54 insertions, 48 deletions

diff --git a/drivers/usb/core/inode.c b/drivers/usb/core/inode.c
index c44bbedec817..4ddc453023a2 100644
--- a/drivers/usb/core/inode.c
+++ b/drivers/usb/core/inode.c
@@ -186,7 +186,7 @@ static void update_bus(struct dentry *bus)
 
         down(&bus->d_inode->i_sem);
 
-        list_for_each_entry(dev, &bus->d_subdirs, d_child)
+        list_for_each_entry(dev, &bus->d_subdirs, d_u.d_child)
                 if (dev->d_inode)
                         update_dev(dev);
 
@@ -203,7 +203,7 @@ static void update_sb(struct super_block *sb)
 
         down(&root->d_inode->i_sem);
 
-        list_for_each_entry(bus, &root->d_subdirs, d_child) {
+        list_for_each_entry(bus, &root->d_subdirs, d_u.d_child) {
                 if (bus->d_inode) {
                         switch (S_IFMT & bus->d_inode->i_mode) {
                         case S_IFDIR:
@@ -319,7 +319,7 @@ static int usbfs_empty (struct dentry *dentry)
         spin_lock(&dcache_lock);
 
         list_for_each(list, &dentry->d_subdirs) {
-                struct dentry *de = list_entry(list, struct dentry, d_child);
+                struct dentry *de = list_entry(list, struct dentry, d_u.d_child);
                 if (usbfs_positive(de)) {
                         spin_unlock(&dcache_lock);
                         return 0;
diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index fca83e28edcf..385bed09b0d8 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -209,7 +209,7 @@ static inline int simple_empty_nolock(struct dentry *dentry)
         struct dentry *child;
         int ret = 0;
 
-        list_for_each_entry(child, &dentry->d_subdirs, d_child)
+        list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
                 if (simple_positive(child))
                         goto out;
         ret = 1;
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index feb6ac427d05..dc39589df165 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -105,7 +105,7 @@ repeat:
         next = this_parent->d_subdirs.next;
 resume:
         while (next != &this_parent->d_subdirs) {
-                struct dentry *dentry = list_entry(next, struct dentry, d_child);
+                struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
 
                 /* Negative dentry - give up */
                 if (!simple_positive(dentry)) {
@@ -138,7 +138,7 @@ resume:
         }
 
         if (this_parent != top) {
-                next = this_parent->d_child.next;
+                next = this_parent->d_u.d_child.next;
                 this_parent = this_parent->d_parent;
                 goto resume;
         }
@@ -163,7 +163,7 @@ repeat:
         next = this_parent->d_subdirs.next;
 resume:
         while (next != &this_parent->d_subdirs) {
-                struct dentry *dentry = list_entry(next, struct dentry, d_child);
+                struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
 
                 /* Negative dentry - give up */
                 if (!simple_positive(dentry)) {
@@ -199,7 +199,7 @@ cont:
         }
 
         if (this_parent != parent) {
-                next = this_parent->d_child.next;
+                next = this_parent->d_u.d_child.next;
                 this_parent = this_parent->d_parent;
                 goto resume;
         }
@@ -238,7 +238,7 @@ static struct dentry *autofs4_expire(struct super_block *sb,
         /* On exit from the loop expire is set to a dgot dentry
          * to expire or it's NULL */
         while ( next != &root->d_subdirs ) {
-                struct dentry *dentry = list_entry(next, struct dentry, d_child);
+                struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
 
                 /* Negative dentry - give up */
                 if ( !simple_positive(dentry) ) {
@@ -302,7 +302,7 @@ next:
                         expired, (int)expired->d_name.len, expired->d_name.name);
                 spin_lock(&dcache_lock);
                 list_del(&expired->d_parent->d_subdirs);
-                list_add(&expired->d_parent->d_subdirs, &expired->d_child);
+                list_add(&expired->d_parent->d_subdirs, &expired->d_u.d_child);
                 spin_unlock(&dcache_lock);
                 return expired;
         }
diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c
index 818b37be5153..2d3082854a29 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -91,7 +91,7 @@ repeat:
         next = this_parent->d_subdirs.next;
 resume:
         while (next != &this_parent->d_subdirs) {
-                struct dentry *dentry = list_entry(next, struct dentry, d_child);
+                struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
 
                 /* Negative dentry - don`t care */
                 if (!simple_positive(dentry)) {
@@ -117,7 +117,7 @@ resume:
         if (this_parent != sbi->root) {
                 struct dentry *dentry = this_parent;
 
-                next = this_parent->d_child.next;
+                next = this_parent->d_u.d_child.next;
                 this_parent = this_parent->d_parent;
                 spin_unlock(&dcache_lock);
                 DPRINTK("parent dentry %p %.*s",
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 2a771ec66956..2241405ffc41 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -143,7 +143,8 @@ static int autofs4_dcache_readdir(struct file * filp, void * dirent, filldir_t f
                         }
 
                         while(1) {
-                                struct dentry *de = list_entry(list, struct dentry, d_child);
+                                struct dentry *de = list_entry(list,
+                                                struct dentry, d_u.d_child);
 
                                 if (!d_unhashed(de) && de->d_inode) {
                                         spin_unlock(&dcache_lock);
diff --git a/fs/coda/cache.c b/fs/coda/cache.c
index 80072fd9b7fa..c607d923350a 100644
--- a/fs/coda/cache.c
+++ b/fs/coda/cache.c
@@ -93,7 +93,7 @@ static void coda_flag_children(struct dentry *parent, int flag)
         spin_lock(&dcache_lock);
         list_for_each(child, &parent->d_subdirs)
         {
-                de = list_entry(child, struct dentry, d_child);
+                de = list_entry(child, struct dentry, d_u.d_child);
                 /* don't know what to do with negative dentries */
                 if ( ! de->d_inode ) 
                         continue;
diff --git a/fs/dcache.c b/fs/dcache.c
index 17e439138681..1536f15c4d4c 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -71,7 +71,7 @@ struct dentry_stat_t dentry_stat = {
 
 static void d_callback(struct rcu_head *head)
 {
-        struct dentry * dentry = container_of(head, struct dentry, d_rcu);
+        struct dentry * dentry = container_of(head, struct dentry, d_u.d_rcu);
 
         if (dname_external(dentry))
                 kfree(dentry->d_name.name);
@@ -86,7 +86,7 @@ static void d_free(struct dentry *dentry)
 {
         if (dentry->d_op && dentry->d_op->d_release)
                 dentry->d_op->d_release(dentry);
-        call_rcu(&dentry->d_rcu, d_callback);
+        call_rcu(&dentry->d_u.d_rcu, d_callback);
 }
 
 /*
@@ -193,7 +193,7 @@ kill_it: {
                         list_del(&dentry->d_lru);
                         dentry_stat.nr_unused--;
                 }
-                list_del(&dentry->d_child);
+                list_del(&dentry->d_u.d_child);
                 dentry_stat.nr_dentry--;        /* For d_free, below */
                 /*drops the locks, at that point nobody can reach this dentry */
                 dentry_iput(dentry);
@@ -367,7 +367,7 @@ static inline void prune_one_dentry(struct dentry * dentry)
         struct dentry * parent;
 
         __d_drop(dentry);
-        list_del(&dentry->d_child);
+        list_del(&dentry->d_u.d_child);
         dentry_stat.nr_dentry--;        /* For d_free, below */
         dentry_iput(dentry);
         parent = dentry->d_parent;
@@ -518,7 +518,7 @@ repeat:
 resume:
         while (next != &this_parent->d_subdirs) {
                 struct list_head *tmp = next;
-                struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
+                struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
                 next = tmp->next;
                 /* Have we found a mount point ? */
                 if (d_mountpoint(dentry))
@@ -532,7 +532,7 @@ resume:
          * All done at this level ... ascend and resume the search.
          */
         if (this_parent != parent) {
-                next = this_parent->d_child.next; 
+                next = this_parent->d_u.d_child.next;
                 this_parent = this_parent->d_parent;
                 goto resume;
         }
@@ -569,7 +569,7 @@ repeat:
 resume:
         while (next != &this_parent->d_subdirs) {
                 struct list_head *tmp = next;
-                struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
+                struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
                 next = tmp->next;
 
                 if (!list_empty(&dentry->d_lru)) {
@@ -610,7 +610,7 @@ dentry->d_parent->d_name.name, dentry->d_name.name, found);
          * All done at this level ... ascend and resume the search.
          */
         if (this_parent != parent) {
-                next = this_parent->d_child.next; 
+                next = this_parent->d_u.d_child.next;
                 this_parent = this_parent->d_parent;
 #ifdef DCACHE_DEBUG
 printk(KERN_DEBUG "select_parent: ascending to %s/%s, found=%d\n",
@@ -753,12 +753,12 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
                 dentry->d_parent = dget(parent);
                 dentry->d_sb = parent->d_sb;
         } else {
-                INIT_LIST_HEAD(&dentry->d_child);
+                INIT_LIST_HEAD(&dentry->d_u.d_child);
         }
 
         spin_lock(&dcache_lock);
         if (parent)
-                list_add(&dentry->d_child, &parent->d_subdirs);
+                list_add(&dentry->d_u.d_child, &parent->d_subdirs);
         dentry_stat.nr_dentry++;
         spin_unlock(&dcache_lock);
 
@@ -1310,8 +1310,8 @@ already_unhashed:
         /* Unhash the target: dput() will then get rid of it */
         __d_drop(target);
 
-        list_del(&dentry->d_child);
-        list_del(&target->d_child);
+        list_del(&dentry->d_u.d_child);
+        list_del(&target->d_u.d_child);
 
         /* Switch the names.. */
         switch_names(dentry, target);
@@ -1322,15 +1322,15 @@ already_unhashed:
         if (IS_ROOT(dentry)) {
                 dentry->d_parent = target->d_parent;
                 target->d_parent = target;
-                INIT_LIST_HEAD(&target->d_child);
+                INIT_LIST_HEAD(&target->d_u.d_child);
         } else {
                 do_switch(dentry->d_parent, target->d_parent);
 
                 /* And add them back to the (new) parent lists */
-                list_add(&target->d_child, &target->d_parent->d_subdirs);
+                list_add(&target->d_u.d_child, &target->d_parent->d_subdirs);
         }
 
-        list_add(&dentry->d_child, &dentry->d_parent->d_subdirs);
+        list_add(&dentry->d_u.d_child, &dentry->d_parent->d_subdirs);
         spin_unlock(&target->d_lock);
         spin_unlock(&dentry->d_lock);
         write_sequnlock(&rename_lock);
@@ -1568,7 +1568,7 @@ repeat:
 resume:
         while (next != &this_parent->d_subdirs) {
                 struct list_head *tmp = next;
-                struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
+                struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
                 next = tmp->next;
                 if (d_unhashed(dentry)||!dentry->d_inode)
                         continue;
@@ -1579,7 +1579,7 @@ resume:
                 atomic_dec(&dentry->d_count);
         }
         if (this_parent != root) {
-                next = this_parent->d_child.next; 
+                next = this_parent->d_u.d_child.next;
                 atomic_dec(&this_parent->d_count);
                 this_parent = this_parent->d_parent;
                 goto resume;
diff --git a/fs/libfs.c b/fs/libfs.c
index 58101dff2c66..9c50523382e7 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -93,16 +93,16 @@ loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin)
                         loff_t n = file->f_pos - 2;
 
                         spin_lock(&dcache_lock);
-                        list_del(&cursor->d_child);
+                        list_del(&cursor->d_u.d_child);
                         p = file->f_dentry->d_subdirs.next;
                         while (n && p != &file->f_dentry->d_subdirs) {
                                 struct dentry *next;
-                                next = list_entry(p, struct dentry, d_child);
+                                next = list_entry(p, struct dentry, d_u.d_child);
                                 if (!d_unhashed(next) && next->d_inode)
                                         n--;
                                 p = p->next;
                         }
-                        list_add_tail(&cursor->d_child, p);
+                        list_add_tail(&cursor->d_u.d_child, p);
                         spin_unlock(&dcache_lock);
                 }
         }
@@ -126,7 +126,7 @@ int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
 {
         struct dentry *dentry = filp->f_dentry;
         struct dentry *cursor = filp->private_data;
-        struct list_head *p, *q = &cursor->d_child;
+        struct list_head *p, *q = &cursor->d_u.d_child;
         ino_t ino;
         int i = filp->f_pos;
 
@@ -153,7 +153,7 @@ int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
                         }
                         for (p=q->next; p != &dentry->d_subdirs; p=p->next) {
                                 struct dentry *next;
-                                next = list_entry(p, struct dentry, d_child);
+                                next = list_entry(p, struct dentry, d_u.d_child);
                                 if (d_unhashed(next) || !next->d_inode)
                                         continue;
 
@@ -261,7 +261,7 @@ int simple_empty(struct dentry *dentry)
         int ret = 0;
 
         spin_lock(&dcache_lock);
-        list_for_each_entry(child, &dentry->d_subdirs, d_child)
+        list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
                 if (simple_positive(child))
                         goto out;
         ret = 1;
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index a9f7a8ab1d59..cfd76f431dc0 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -365,7 +365,7 @@ ncp_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos)
         spin_lock(&dcache_lock);
         next = parent->d_subdirs.next;
         while (next != &parent->d_subdirs) {
-                dent = list_entry(next, struct dentry, d_child);
+                dent = list_entry(next, struct dentry, d_u.d_child);
                 if ((unsigned long)dent->d_fsdata == fpos) {
                         if (dent->d_inode)
                                 dget_locked(dent);
diff --git a/fs/ncpfs/ncplib_kernel.h b/fs/ncpfs/ncplib_kernel.h
index 9e4dc30c2435..799e5c2bec55 100644
--- a/fs/ncpfs/ncplib_kernel.h
+++ b/fs/ncpfs/ncplib_kernel.h
@@ -196,7 +196,7 @@ ncp_renew_dentries(struct dentry *parent)
         spin_lock(&dcache_lock);
         next = parent->d_subdirs.next;
         while (next != &parent->d_subdirs) {
-                dentry = list_entry(next, struct dentry, d_child);
+                dentry = list_entry(next, struct dentry, d_u.d_child);
 
                 if (dentry->d_fsdata == NULL)
                         ncp_age_dentry(server, dentry);
@@ -218,7 +218,7 @@ ncp_invalidate_dircache_entries(struct dentry *parent)
         spin_lock(&dcache_lock);
         next = parent->d_subdirs.next;
         while (next != &parent->d_subdirs) {
-                dentry = list_entry(next, struct dentry, d_child);
+                dentry = list_entry(next, struct dentry, d_u.d_child);
                 dentry->d_fsdata = NULL;
                 ncp_age_dentry(server, dentry);
                 next = next->next;
diff --git a/fs/smbfs/cache.c b/fs/smbfs/cache.c
index f3e6b81288ab..74b86d9725a6 100644
--- a/fs/smbfs/cache.c
+++ b/fs/smbfs/cache.c
@@ -66,7 +66,7 @@ smb_invalidate_dircache_entries(struct dentry *parent)
         spin_lock(&dcache_lock);
         next = parent->d_subdirs.next;
         while (next != &parent->d_subdirs) {
-                dentry = list_entry(next, struct dentry, d_child);
+                dentry = list_entry(next, struct dentry, d_u.d_child);
                 dentry->d_fsdata = NULL;
                 smb_age_dentry(server, dentry);
                 next = next->next;
@@ -100,7 +100,7 @@ smb_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos)
         spin_lock(&dcache_lock);
         next = parent->d_subdirs.next;
         while (next != &parent->d_subdirs) {
-                dent = list_entry(next, struct dentry, d_child);
+                dent = list_entry(next, struct dentry, d_u.d_child);
                 if ((unsigned long)dent->d_fsdata == fpos) {
                         if (dent->d_inode)
                                 dget_locked(dent);
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 46a2ba617595..a3ed5e059d47 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -95,14 +95,19 @@ struct dentry {
         struct qstr d_name;
 
         struct list_head d_lru;         /* LRU list */
-        struct list_head d_child;       /* child of parent list */
+        /*
+         * d_child and d_rcu can share memory
+         */
+        union {
+                struct list_head d_child;       /* child of parent list */
+                struct rcu_head d_rcu;
+        } d_u;
         struct list_head d_subdirs;     /* our children */
         struct list_head d_alias;       /* inode alias list */
         unsigned long d_time;           /* used by d_revalidate */
         struct dentry_operations *d_op;
         struct super_block *d_sb;       /* The root of the dentry tree */
         void *d_fsdata;                 /* fs-specific data */
-        struct rcu_head d_rcu;
         struct dcookie_struct *d_cookie; /* cookie, if any */
         int d_mounted;
         unsigned char d_iname[DNAME_INLINE_LEN_MIN];    /* small names */
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index e04c2da9dadb..eab64e23bcae 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -331,7 +331,7 @@ static void cpuset_d_remove_dir(struct dentry *dentry)
         spin_lock(&dcache_lock);
         node = dentry->d_subdirs.next;
         while (node != &dentry->d_subdirs) {
-                struct dentry *d = list_entry(node, struct dentry, d_child);
+                struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
                 list_del_init(node);
                 if (d->d_inode) {
                         d = dget_locked(d);
@@ -343,7 +343,7 @@ static void cpuset_d_remove_dir(struct dentry *dentry)
                 }
                 node = dentry->d_subdirs.next;
         }
-        list_del_init(&dentry->d_child);
+        list_del_init(&dentry->d_u.d_child);
         spin_unlock(&dcache_lock);
         remove_dir(dentry);
 }
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 24cc23af9b95..e14c1cae7460 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -495,7 +495,7 @@ rpc_depopulate(struct dentry *parent)
 repeat:
         spin_lock(&dcache_lock);
         list_for_each_safe(pos, next, &parent->d_subdirs) {
-                dentry = list_entry(pos, struct dentry, d_child);
+                dentry = list_entry(pos, struct dentry, d_u.d_child);
                 spin_lock(&dentry->d_lock);
                 if (!d_unhashed(dentry)) {
                         dget_locked(dentry);
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index e59da6398d44..b5fa02d17b1e 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -889,7 +889,7 @@ static void sel_remove_bools(struct dentry *de)
         spin_lock(&dcache_lock);
         node = de->d_subdirs.next;
         while (node != &de->d_subdirs) {
-                struct dentry *d = list_entry(node, struct dentry, d_child);
+                struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
                 list_del_init(node);
 
                 if (d->d_inode) {