vfs: factor out inode hash head calculation

In preparation for changing the inode hash table implementation.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: linux-fsdevel@vger.kernel.org

1 files changed, 25 insertions, 19 deletions

diff --git a/fs/inode.c b/fs/inode.c
index 4f8984b97df0..dee58838ec20 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -59,6 +59,22 @@ static unsigned int i_hash_shift __read_mostly;
 static struct hlist_head *inode_hashtable __read_mostly;
 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_hash_lock);
 
+static unsigned long hash(struct super_block *sb, unsigned long hashval)
+{
+	unsigned long tmp;
+
+	tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) /
+			L1_CACHE_BYTES;
+	tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> i_hash_shift);
+	return tmp & i_hash_mask;
+}
+
+static inline struct hlist_head *i_hash_head(struct super_block *sb,
+		unsigned int hashval)
+{
+	return inode_hashtable + hash(sb, hashval);
+}
+
 /*
  * Empty aops. Can be used for the cases where the user does not
  * define any of the address_space operations.
@@ -505,16 +521,6 @@ static inline void inode_sb_list_del(struct inode *inode)
 	}
 }
 
-static unsigned long hash(struct super_block *sb, unsigned long hashval)
-{
-	unsigned long tmp;
-
-	tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) /
-			L1_CACHE_BYTES;
-	tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> i_hash_shift);
-	return tmp & i_hash_mask;
-}
-
 /**
  *	__insert_inode_hash - hash an inode
  *	@inode: unhashed inode
@@ -1190,7 +1196,7 @@ struct inode *inode_insert5(struct inode *inode, unsigned long hashval,
 			    int (*test)(struct inode *, void *),
 			    int (*set)(struct inode *, void *), void *data)
 {
-	struct hlist_head *head = inode_hashtable + hash(inode->i_sb, hashval);
+	struct hlist_head *head = i_hash_head(inode->i_sb, hashval);
 	struct inode *old;
 
 again:
@@ -1294,7 +1300,7 @@ EXPORT_SYMBOL(iget5_locked);
  */
 struct inode *iget_locked(struct super_block *sb, unsigned long ino)
 {
-	struct hlist_head *head = inode_hashtable + hash(sb, ino);
+	struct hlist_head *head = i_hash_head(sb, ino);
 	struct inode *inode;
 again:
 	spin_lock(&inode_hash_lock);
@@ -1362,7 +1368,7 @@ EXPORT_SYMBOL(iget_locked);
  */
 static int test_inode_iunique(struct super_block *sb, unsigned long ino)
 {
-	struct hlist_head *b = inode_hashtable + hash(sb, ino);
+	struct hlist_head *b = i_hash_head(sb, ino);
 	struct inode *inode;
 
 	hlist_for_each_entry_rcu(inode, b, i_hash) {
@@ -1449,7 +1455,7 @@ EXPORT_SYMBOL(igrab);
 struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval,
 		int (*test)(struct inode *, void *), void *data)
 {
-	struct hlist_head *head = inode_hashtable + hash(sb, hashval);
+	struct hlist_head *head = i_hash_head(sb, hashval);
 	struct inode *inode;
 
 	spin_lock(&inode_hash_lock);
@@ -1504,7 +1510,7 @@ EXPORT_SYMBOL(ilookup5);
  */
 struct inode *ilookup(struct super_block *sb, unsigned long ino)
 {
-	struct hlist_head *head = inode_hashtable + hash(sb, ino);
+	struct hlist_head *head = i_hash_head(sb, ino);
 	struct inode *inode;
 again:
 	spin_lock(&inode_hash_lock);
@@ -1553,7 +1559,7 @@ struct inode *find_inode_nowait(struct super_block *sb,
 					     void *),
 				void *data)
 {
-	struct hlist_head *head = inode_hashtable + hash(sb, hashval);
+	struct hlist_head *head = i_hash_head(sb, hashval);
 	struct inode *inode, *ret_inode = NULL;
 	int mval;
 
@@ -1598,7 +1604,7 @@ EXPORT_SYMBOL(find_inode_nowait);
 struct inode *find_inode_rcu(struct super_block *sb, unsigned long hashval,
 			     int (*test)(struct inode *, void *), void *data)
 {
-	struct hlist_head *head = inode_hashtable + hash(sb, hashval);
+	struct hlist_head *head = i_hash_head(sb, hashval);
 	struct inode *inode;
 
 	RCU_LOCKDEP_WARN(!rcu_read_lock_held(),
@@ -1636,7 +1642,7 @@ EXPORT_SYMBOL(find_inode_rcu);
 struct inode *find_inode_by_ino_rcu(struct super_block *sb,
 				    unsigned long ino)
 {
-	struct hlist_head *head = inode_hashtable + hash(sb, ino);
+	struct hlist_head *head = i_hash_head(sb, ino);
 	struct inode *inode;
 
 	RCU_LOCKDEP_WARN(!rcu_read_lock_held(),
@@ -1656,7 +1662,7 @@ int insert_inode_locked(struct inode *inode)
 {
 	struct super_block *sb = inode->i_sb;
 	ino_t ino = inode->i_ino;
-	struct hlist_head *head = inode_hashtable + hash(sb, ino);
+	struct hlist_head *head = i_hash_head(sb, ino);
 
 	while (1) {
 		struct inode *old = NULL;