Merge branch 'hash' of git://ftp.sciencehorizons.net/linux

[cascardo/linux.git] / include / linux / dcache.h

diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 7e9422c..484c879 100644 (file)
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -10,6 +10,7 @@
 #include <linux/cache.h>
 #include <linux/rcupdate.h>
 #include <linux/lockref.h>
+#include <linux/stringhash.h>
 
 struct path;
 struct vfsmount;
@@ -52,9 +53,6 @@ struct qstr {
 };
 
 #define QSTR_INIT(n,l) { { { .len = l } }, .name = n }
-#define hashlen_hash(hashlen) ((u32) (hashlen))
-#define hashlen_len(hashlen)  ((u32)((hashlen) >> 32))
-#define hashlen_create(hash,len) (((u64)(len)<<32)|(u32)(hash))
 
 struct dentry_stat_t {
        long nr_dentry;
@@ -65,29 +63,6 @@ struct dentry_stat_t {
 };
 extern struct dentry_stat_t dentry_stat;
 
-/* Name hashing routines. Initial hash value */
-/* Hash courtesy of the R5 hash in reiserfs modulo sign bits */
-#define init_name_hash()               0
-
-/* partial hash update function. Assume roughly 4 bits per character */
-static inline unsigned long
-partial_name_hash(unsigned long c, unsigned long prevhash)
-{
-       return (prevhash + (c << 4) + (c >> 4)) * 11;
-}
-
-/*
- * Finally: cut down the number of bits to a int value (and try to avoid
- * losing bits)
- */
-static inline unsigned long end_name_hash(unsigned long hash)
-{
-       return (unsigned int) hash;
-}
-
-/* Compute the hash for a name string. */
-extern unsigned int full_name_hash(const unsigned char *, unsigned int);
-
 /*
  * Try to keep struct dentry aligned on 64 byte cachelines (this will
  * give reasonable cacheline footprint with larger lines without the
@@ -123,7 +98,10 @@ struct dentry {
        unsigned long d_time;           /* used by d_revalidate */
        void *d_fsdata;                 /* fs-specific data */
 
-       struct list_head d_lru;         /* LRU list */
+       union {
+               struct list_head d_lru;         /* LRU list */
+               wait_queue_head_t *d_wait;      /* in-lookup ones only */
+       };
        struct list_head d_child;       /* child of parent list */
        struct list_head d_subdirs;     /* our children */
        /*
@@ -131,6 +109,7 @@ struct dentry {
         */
        union {
                struct hlist_node d_alias;      /* inode alias list */
+               struct hlist_bl_node d_in_lookup_hash;  /* only for in-lookup ones */
                struct rcu_head d_rcu;
        } d_u;
 };
@@ -232,6 +211,8 @@ struct dentry_operations {
 #define DCACHE_ENCRYPTED_WITH_KEY      0x04000000 /* dir is encrypted with a valid key */
 #define DCACHE_OP_REAL                 0x08000000
 
+#define DCACHE_PAR_LOOKUP              0x10000000 /* being looked up (with parent locked shared) */
+
 extern seqlock_t rename_lock;
 
 /*
@@ -248,6 +229,8 @@ extern void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op
 /* allocate/de-allocate */
 extern struct dentry * d_alloc(struct dentry *, const struct qstr *);
 extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *);
+extern struct dentry * d_alloc_parallel(struct dentry *, const struct qstr *,
+                                       wait_queue_head_t *);
 extern struct dentry * d_splice_alias(struct inode *, struct dentry *);
 extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *);
 extern struct dentry * d_exact_alias(struct dentry *, struct inode *);
@@ -367,6 +350,22 @@ static inline void dont_mount(struct dentry *dentry)
        spin_unlock(&dentry->d_lock);
 }
 
+extern void __d_lookup_done(struct dentry *);
+
+static inline int d_in_lookup(struct dentry *dentry)
+{
+       return dentry->d_flags & DCACHE_PAR_LOOKUP;
+}
+
+static inline void d_lookup_done(struct dentry *dentry)
+{
+       if (unlikely(d_in_lookup(dentry))) {
+               spin_lock(&dentry->d_lock);
+               __d_lookup_done(dentry);
+               spin_unlock(&dentry->d_lock);
+       }
+}
+
 extern void dput(struct dentry *);
 
 static inline bool d_managed(const struct dentry *dentry)