fs: dcache scale hash

Add a new lock, dcache_hash_lock, to protect the dcache hash table from
concurrent modification. d_hash is also protected by d_lock.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
This commit is contained in:
Nick Piggin
2011-01-07 17:49:30 +11:00
parent ec2447c278
commit 789680d1ee
2 changed files with 64 additions and 44 deletions

View File

@ -184,39 +184,6 @@ struct dentry_operations {
extern spinlock_t dcache_lock;
extern seqlock_t rename_lock;
/**
* d_drop - drop a dentry
* @dentry: dentry to drop
*
* d_drop() unhashes the entry from the parent dentry hashes, so that it won't
* be found through a VFS lookup any more. Note that this is different from
* deleting the dentry - d_delete will try to mark the dentry negative if
* possible, giving a successful _negative_ lookup, while d_drop will
* just make the cache lookup fail.
*
* d_drop() is used mainly for stuff that wants to invalidate a dentry for some
* reason (NFS timeouts or autofs deletes).
*
* __d_drop requires dentry->d_lock.
*/
static inline void __d_drop(struct dentry *dentry)
{
if (!(dentry->d_flags & DCACHE_UNHASHED)) {
dentry->d_flags |= DCACHE_UNHASHED;
hlist_del_rcu(&dentry->d_hash);
}
}
static inline void d_drop(struct dentry *dentry)
{
spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
}
static inline int dname_external(struct dentry *dentry)
{
return dentry->d_name.name != dentry->d_iname;
@ -228,6 +195,8 @@ static inline int dname_external(struct dentry *dentry)
extern void d_instantiate(struct dentry *, struct inode *);
extern struct dentry * d_instantiate_unique(struct dentry *, struct inode *);
extern struct dentry * d_materialise_unique(struct dentry *, struct inode *);
extern void __d_drop(struct dentry *dentry);
extern void d_drop(struct dentry *dentry);
extern void d_delete(struct dentry *);
/* allocate/de-allocate */