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 0f9a977..484c879 100644 (file)
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -98,7 +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 */
        /*
@@ -106,6 +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;
 };
@@ -207,6 +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;
 
 /*
@@ -223,6 +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 *);
@@ -342,6 +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)