Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull misc vfs updates from Al Viro:
 "All kinds of misc stuff, without any unifying topic, from various
  people.

  Neil's d_anon patch, several bugfixes, introduction of kvmalloc
  analogue of kmemdup_user(), extending bitfield.h to deal with
  fixed-endians, assorted cleanups all over the place..."

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
  alpha: osf_sys.c: use timespec64 where appropriate
  alpha: osf_sys.c: fix put_tv32 regression
  jffs2: Fix use-after-free bug in jffs2_iget()'s error handling path
  dcache: delete unused d_hash_mask
  dcache: subtract d_hash_shift from 32 in advance
  fs/buffer.c: fold init_buffer() into init_page_buffers()
  fs: fold __inode_permission() into inode_permission()
  fs: add RWF_APPEND
  sctp: use vmemdup_user() rather than badly open-coding memdup_user()
  snd_ctl_elem_init_enum_names(): switch to vmemdup_user()
  replace_user_tlv(): switch to vmemdup_user()
  new primitive: vmemdup_user()
  memdup_user(): switch to GFP_USER
  eventfd: fold eventfd_ctx_get() into eventfd_ctx_fileget()
  eventfd: fold eventfd_ctx_read() into eventfd_read()
  eventfd: convert to use anon_inode_getfd()
  nfs4file: get rid of pointless include of btrfs.h
  uvc_v4l2: clean copyin/copyout up
  vme_user: don't use __copy_..._user()
  usx2y: don't bother with memdup_user() for 16-byte structure
  ...

fs/dcache.c

@@ -32,7 +32,6 @@
 #include <linux/swap.h>
 #include <linux/bootmem.h>
 #include <linux/fs_struct.h>
-#include <linux/hardirq.h>
 #include <linux/bit_spinlock.h>
 #include <linux/rculist_bl.h>
 #include <linux/prefetch.h>
@@ -49,8 +48,8 @@
  *   - i_dentry, d_u.d_alias, d_inode of aliases
  * dcache_hash_bucket lock protects:
  *   - the dcache hash table
- * s_anon bl list spinlock protects:
- *   - the s_anon list (see __d_drop)
+ * s_roots bl list spinlock protects:
+ *   - the s_roots list (see __d_drop)
  * dentry->d_sb->s_dentry_lru_lock protects:
  *   - the dcache lru lists and counters
  * d_lock protects:
@@ -68,7 +67,7 @@
  *   dentry->d_lock
  *     dentry->d_sb->s_dentry_lru_lock
  *     dcache_hash_bucket lock
- *     s_anon lock
+ *     s_roots lock
  *
  * If there is an ancestor relationship:
  * dentry->d_parent->...->d_parent->d_lock
@@ -104,14 +103,13 @@ EXPORT_SYMBOL(slash_name);
  * information, yet avoid using a prime hash-size or similar.
  */
 
-static unsigned int d_hash_mask __read_mostly;
 static unsigned int d_hash_shift __read_mostly;
 
 static struct hlist_bl_head *dentry_hashtable __read_mostly;
 
 static inline struct hlist_bl_head *d_hash(unsigned int hash)
 {
-	return dentry_hashtable + (hash >> (32 - d_hash_shift));
+	return dentry_hashtable + (hash >> d_hash_shift);
 }
 
 #define IN_LOOKUP_SHIFT 10
@@ -477,10 +475,10 @@ void __d_drop(struct dentry *dentry)
 		/*
 		 * Hashed dentries are normally on the dentry hashtable,
 		 * with the exception of those newly allocated by
-		 * d_obtain_alias, which are always IS_ROOT:
+		 * d_obtain_root, which are always IS_ROOT:
 		 */
 		if (unlikely(IS_ROOT(dentry)))
-			b = &dentry->d_sb->s_anon;
+			b = &dentry->d_sb->s_roots;
 		else
 			b = d_hash(dentry->d_name.hash);
 
@@ -1500,8 +1498,8 @@ void shrink_dcache_for_umount(struct super_block *sb)
 	sb->s_root = NULL;
 	do_one_tree(dentry);
 
-	while (!hlist_bl_empty(&sb->s_anon)) {
-		dentry = dget(hlist_bl_entry(hlist_bl_first(&sb->s_anon), struct dentry, d_hash));
+	while (!hlist_bl_empty(&sb->s_roots)) {
+		dentry = dget(hlist_bl_entry(hlist_bl_first(&sb->s_roots), struct dentry, d_hash));
 		do_one_tree(dentry);
 	}
 }
@@ -1964,9 +1962,11 @@ static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected)
 	spin_lock(&tmp->d_lock);
 	__d_set_inode_and_type(tmp, inode, add_flags);
 	hlist_add_head(&tmp->d_u.d_alias, &inode->i_dentry);
-	hlist_bl_lock(&tmp->d_sb->s_anon);
-	hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon);
-	hlist_bl_unlock(&tmp->d_sb->s_anon);
+	if (!disconnected) {
+		hlist_bl_lock(&tmp->d_sb->s_roots);
+		hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_roots);
+		hlist_bl_unlock(&tmp->d_sb->s_roots);
+	}
 	spin_unlock(&tmp->d_lock);
 	spin_unlock(&inode->i_lock);
 
@@ -3585,9 +3585,10 @@ static void __init dcache_init_early(void)
 					13,
 					HASH_EARLY | HASH_ZERO,
 					&d_hash_shift,
-					&d_hash_mask,
+					NULL,
 					0,
 					0);
+	d_hash_shift = 32 - d_hash_shift;
 }
 
 static void __init dcache_init(void)
@@ -3611,9 +3612,10 @@ static void __init dcache_init(void)
 					13,
 					HASH_ZERO,
 					&d_hash_shift,
-					&d_hash_mask,
+					NULL,
 					0,
 					0);
+	d_hash_shift = 32 - d_hash_shift;
 }
 
 /* SLAB cache for __getname() consumers */