diff options
| -rw-r--r-- | fs/dcache.c | 133 | ||||
| -rw-r--r-- | fs/super.c | 3 | ||||
| -rw-r--r-- | include/linux/dcache.h | 3 | ||||
| -rw-r--r-- | include/linux/fs.h | 3 |
4 files changed, 89 insertions, 53 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 07d1f6862dc..9f04e1ba75b 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -33,14 +33,18 @@ #include <linux/bootmem.h> #include <linux/fs_struct.h> #include <linux/hardirq.h> +#include <linux/bit_spinlock.h> +#include <linux/rculist_bl.h> #include "internal.h" /* * Usage: * dcache_inode_lock protects: * - i_dentry, d_alias, d_inode - * dcache_hash_lock protects: - * - the dcache hash table, s_anon lists + * dcache_hash_bucket lock protects: + * - the dcache hash table + * s_anon bl list spinlock protects: + * - the s_anon list (see __d_drop) * dcache_lru_lock protects: * - the dcache lru lists and counters * d_lock protects: @@ -57,7 +61,8 @@ * dcache_inode_lock * dentry->d_lock * dcache_lru_lock - * dcache_hash_lock + * dcache_hash_bucket lock + * s_anon lock * * If there is an ancestor relationship: * dentry->d_parent->...->d_parent->d_lock @@ -74,7 +79,6 @@ int sysctl_vfs_cache_pressure __read_mostly = 100; EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure); __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_inode_lock); -static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_hash_lock); static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock); __cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock); @@ -96,7 +100,29 @@ static struct kmem_cache *dentry_cache __read_mostly; static unsigned int d_hash_mask __read_mostly; static unsigned int d_hash_shift __read_mostly; -static struct hlist_head *dentry_hashtable __read_mostly; + +struct dcache_hash_bucket { + struct hlist_bl_head head; +}; +static struct dcache_hash_bucket *dentry_hashtable __read_mostly; + +static inline struct dcache_hash_bucket *d_hash(struct dentry *parent, + unsigned long hash) +{ + hash += ((unsigned long) parent ^ GOLDEN_RATIO_PRIME) / L1_CACHE_BYTES; + hash = hash ^ ((hash ^ GOLDEN_RATIO_PRIME) >> D_HASHBITS); + return dentry_hashtable + (hash & D_HASHMASK); +} + +static inline void spin_lock_bucket(struct dcache_hash_bucket *b) +{ + bit_spin_lock(0, (unsigned long *)&b->head.first); +} + +static inline void spin_unlock_bucket(struct dcache_hash_bucket *b) +{ + __bit_spin_unlock(0, (unsigned long *)&b->head.first); +} /* Statistics gathering. */ struct dentry_stat_t dentry_stat = { @@ -144,7 +170,7 @@ static void d_free(struct dentry *dentry) dentry->d_op->d_release(dentry); /* if dentry was never inserted into hash, immediate free is OK */ - if (hlist_unhashed(&dentry->d_hash)) + if (hlist_bl_unhashed(&dentry->d_hash)) __d_free(&dentry->d_u.d_rcu); else call_rcu(&dentry->d_u.d_rcu, __d_free); @@ -302,11 +328,27 @@ static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent) void __d_drop(struct dentry *dentry) { if (!(dentry->d_flags & DCACHE_UNHASHED)) { - dentry->d_flags |= DCACHE_UNHASHED; - spin_lock(&dcache_hash_lock); - hlist_del_rcu(&dentry->d_hash); - spin_unlock(&dcache_hash_lock); - dentry_rcuwalk_barrier(dentry); + if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED)) { + bit_spin_lock(0, + (unsigned long *)&dentry->d_sb->s_anon.first); + dentry->d_flags |= DCACHE_UNHASHED; + hlist_bl_del_init(&dentry->d_hash); + __bit_spin_unlock(0, + (unsigned long *)&dentry->d_sb->s_anon.first); + } else { + struct dcache_hash_bucket *b; + b = d_hash(dentry->d_parent, dentry->d_name.hash); + spin_lock_bucket(b); + /* + * We may not actually need to put DCACHE_UNHASHED + * manipulations under the hash lock, but follow + * the principle of least surprise. + */ + dentry->d_flags |= DCACHE_UNHASHED; + hlist_bl_del_rcu(&dentry->d_hash); + spin_unlock_bucket(b); + dentry_rcuwalk_barrier(dentry); + } } } EXPORT_SYMBOL(__d_drop); @@ -961,8 +1003,8 @@ void shrink_dcache_for_umount(struct super_block *sb) spin_unlock(&dentry->d_lock); shrink_dcache_for_umount_subtree(dentry); - while (!hlist_empty(&sb->s_anon)) { - dentry = hlist_entry(sb->s_anon.first, struct dentry, d_hash); + while (!hlist_bl_empty(&sb->s_anon)) { + dentry = hlist_bl_entry(hlist_bl_first(&sb->s_anon), struct dentry, d_hash); shrink_dcache_for_umount_subtree(dentry); } } @@ -1263,7 +1305,7 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name) dentry->d_sb = NULL; dentry->d_op = NULL; dentry->d_fsdata = NULL; - INIT_HLIST_NODE(&dentry->d_hash); + INIT_HLIST_BL_NODE(&dentry->d_hash); INIT_LIST_HEAD(&dentry->d_lru); INIT_LIST_HEAD(&dentry->d_subdirs); INIT_LIST_HEAD(&dentry->d_alias); @@ -1459,14 +1501,6 @@ struct dentry * d_alloc_root(struct inode * root_inode) } EXPORT_SYMBOL(d_alloc_root); -static inline struct hlist_head *d_hash(struct dentry *parent, - unsigned long hash) -{ - hash += ((unsigned long) parent ^ GOLDEN_RATIO_PRIME) / L1_CACHE_BYTES; - hash = hash ^ ((hash ^ GOLDEN_RATIO_PRIME) >> D_HASHBITS); - return dentry_hashtable + (hash & D_HASHMASK); -} - /** * d_obtain_alias - find or allocate a dentry for a given inode * @inode: inode to allocate the dentry for @@ -1521,11 +1555,11 @@ struct dentry *d_obtain_alias(struct inode *inode) tmp->d_sb = inode->i_sb; tmp->d_inode = inode; tmp->d_flags |= DCACHE_DISCONNECTED; - tmp->d_flags &= ~DCACHE_UNHASHED; list_add(&tmp->d_alias, &inode->i_dentry); - spin_lock(&dcache_hash_lock); - hlist_add_head(&tmp->d_hash, &inode->i_sb->s_anon); - spin_unlock(&dcache_hash_lock); + bit_spin_lock(0, (unsigned long *)&tmp->d_sb->s_anon.first); + tmp->d_flags &= ~DCACHE_UNHASHED; + hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon); + __bit_spin_unlock(0, (unsigned long *)&tmp->d_sb->s_anon.first); spin_unlock(&tmp->d_lock); spin_unlock(&dcache_inode_lock); @@ -1567,7 +1601,7 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry) d_move(new, dentry); iput(inode); } else { - /* already taking dcache_inode_lock, so d_add() by hand */ + /* already got dcache_inode_lock, so d_add() by hand */ __d_instantiate(dentry, inode); spin_unlock(&dcache_inode_lock); security_d_instantiate(dentry, inode); @@ -1702,8 +1736,8 @@ struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name, unsigned int len = name->len; unsigned int hash = name->hash; const unsigned char *str = name->name; - struct hlist_head *head = d_hash(parent, hash); - struct hlist_node *node; + struct dcache_hash_bucket *b = d_hash(parent, hash); + struct hlist_bl_node *node; struct dentry *dentry; /* @@ -1726,7 +1760,7 @@ struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name, * * See Documentation/vfs/dcache-locking.txt for more details. */ - hlist_for_each_entry_rcu(dentry, node, head, d_hash) { + hlist_bl_for_each_entry_rcu(dentry, node, &b->head, d_hash) { struct inode *i; const char *tname; int tlen; @@ -1820,8 +1854,8 @@ struct dentry *__d_lookup(struct dentry *parent, struct qstr *name) unsigned int len = name->len; unsigned int hash = name->hash; const unsigned char *str = name->name; - struct hlist_head *head = d_hash(parent,hash); - struct hlist_node *node; + struct dcache_hash_bucket *b = d_hash(parent, hash); + struct hlist_bl_node *node; struct dentry *found = NULL; struct dentry *dentry; @@ -1847,7 +1881,7 @@ struct dentry *__d_lookup(struct dentry *parent, struct qstr *name) */ rcu_read_lock(); - hlist_for_each_entry_rcu(dentry, node, head, d_hash) { + hlist_bl_for_each_entry_rcu(dentry, node, &b->head, d_hash) { const char *tname; int tlen; @@ -1998,11 +2032,13 @@ again: } EXPORT_SYMBOL(d_delete); -static void __d_rehash(struct dentry * entry, struct hlist_head *list) +static void __d_rehash(struct dentry * entry, struct dcache_hash_bucket *b) { - + BUG_ON(!d_unhashed(entry)); + spin_lock_bucket(b); entry->d_flags &= ~DCACHE_UNHASHED; - hlist_add_head_rcu(&entry->d_hash, list); + hlist_bl_add_head_rcu(&entry->d_hash, &b->head); + spin_unlock_bucket(b); } static void _d_rehash(struct dentry * entry) @@ -2020,9 +2056,7 @@ static void _d_rehash(struct dentry * entry) void d_rehash(struct dentry * entry) { spin_lock(&entry->d_lock); - spin_lock(&dcache_hash_lock); _d_rehash(entry); - spin_unlock(&dcache_hash_lock); spin_unlock(&entry->d_lock); } EXPORT_SYMBOL(d_rehash); @@ -2165,15 +2199,16 @@ void d_move(struct dentry * dentry, struct dentry * target) write_seqcount_begin(&dentry->d_seq); write_seqcount_begin(&target->d_seq); - /* Move the dentry to the target hash queue, if on different bucket */ - spin_lock(&dcache_hash_lock); - if (!d_unhashed(dentry)) - hlist_del_rcu(&dentry->d_hash); + /* __d_drop does write_seqcount_barrier, but they're OK to nest. */ + + /* + * Move the dentry to the target hash queue. Don't bother checking + * for the same hash queue because of how unlikely it is. + */ + __d_drop(dentry); __d_rehash(dentry, d_hash(target->d_parent, target->d_name.hash)); - spin_unlock(&dcache_hash_lock); /* Unhash the target: dput() will then get rid of it */ - /* __d_drop does write_seqcount_barrier, but they're OK to nest. */ __d_drop(target); list_del(&dentry->d_u.d_child); @@ -2369,9 +2404,7 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode) spin_lock(&actual->d_lock); found: - spin_lock(&dcache_hash_lock); _d_rehash(actual); - spin_unlock(&dcache_hash_lock); spin_unlock(&actual->d_lock); spin_unlock(&dcache_inode_lock); out_nolock: @@ -2953,7 +2986,7 @@ static void __init dcache_init_early(void) dentry_hashtable = alloc_large_system_hash("Dentry cache", - sizeof(struct hlist_head), + sizeof(struct dcache_hash_bucket), dhash_entries, 13, HASH_EARLY, @@ -2962,7 +2995,7 @@ static void __init dcache_init_early(void) 0); for (loop = 0; loop < (1 << d_hash_shift); loop++) - INIT_HLIST_HEAD(&dentry_hashtable[loop]); + INIT_HLIST_BL_HEAD(&dentry_hashtable[loop].head); } static void __init dcache_init(void) @@ -2985,7 +3018,7 @@ static void __init dcache_init(void) dentry_hashtable = alloc_large_system_hash("Dentry cache", - sizeof(struct hlist_head), + sizeof(struct dcache_hash_bucket), dhash_entries, 13, 0, @@ -2994,7 +3027,7 @@ static void __init dcache_init(void) 0); for (loop = 0; loop < (1 << d_hash_shift); loop++) - INIT_HLIST_HEAD(&dentry_hashtable[loop]); + INIT_HLIST_BL_HEAD(&dentry_hashtable[loop].head); } /* SLAB cache for __getname() consumers */ diff --git a/fs/super.c b/fs/super.c index ca696155cd9..968ba013011 100644 --- a/fs/super.c +++ b/fs/super.c @@ -30,6 +30,7 @@ #include <linux/idr.h> #include <linux/mutex.h> #include <linux/backing-dev.h> +#include <linux/rculist_bl.h> #include "internal.h" @@ -71,7 +72,7 @@ static struct super_block *alloc_super(struct file_system_type *type) INIT_LIST_HEAD(&s->s_files); #endif INIT_LIST_HEAD(&s->s_instances); - INIT_HLIST_HEAD(&s->s_anon); + INIT_HLIST_BL_HEAD(&s->s_anon); INIT_LIST_HEAD(&s->s_inodes); INIT_LIST_HEAD(&s->s_dentry_lru); init_rwsem(&s->s_umount); diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 8b2064d0292..5f0392ef759 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -4,6 +4,7 @@ #include <asm/atomic.h> #include <linux/list.h> #include <linux/rculist.h> +#include <linux/rculist_bl.h> #include <linux/spinlock.h> #include <linux/seqlock.h> #include <linux/cache.h> @@ -95,7 +96,7 @@ struct dentry { /* RCU lookup touched fields */ unsigned int d_flags; /* protected by d_lock */ seqcount_t d_seq; /* per dentry seqlock */ - struct hlist_node d_hash; /* lookup hash list */ + struct hlist_bl_node d_hash; /* lookup hash list */ struct dentry *d_parent; /* parent directory */ struct qstr d_name; struct inode *d_inode; /* Where the name belongs to - NULL is diff --git a/include/linux/fs.h b/include/linux/fs.h index d5a4d42f655..baf3e556ff0 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -392,6 +392,7 @@ struct inodes_stat_t { #include <linux/capability.h> #include <linux/semaphore.h> #include <linux/fiemap.h> +#include <linux/rculist_bl.h> #include <asm/atomic.h> #include <asm/byteorder.h> @@ -1377,7 +1378,7 @@ struct super_block { const struct xattr_handler **s_xattr; struct list_head s_inodes; /* all inodes */ - struct hlist_head s_anon; /* anonymous dentries for (nfs) exporting */ + struct hlist_bl_head s_anon; /* anonymous dentries for (nfs) exporting */ #ifdef CONFIG_SMP struct list_head __percpu *s_files; #else |