[Cluster-devel] [PATCH 01/15] GFS2: Use RCU for glock hash table
Steven Whitehouse
swhiteho at redhat.com
Tue Mar 15 09:11:31 UTC 2011
This has a number of advantages:
- Reduces contention on the hash table lock
- Makes the code smaller and simpler
- Should speed up glock dumps when under load
- Removes ref count changing in examine_bucket
- No longer need hash chain lock in glock_put() in common case
There are some further changes which this enables and which
we may do in the future. One is to look at using SLAB_RCU,
and another is to look at using a per-cpu counter for the
per-sb glock counter, since that is touched twice in the
lifetime of each glock (but only used at umount time).
Signed-off-by: Steven Whitehouse <swhiteho at redhat.com>
Cc: Paul E. McKenney <paulmck at linux.vnet.ibm.com>
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 08a8beb..c75d499 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -26,6 +26,9 @@
#include <linux/freezer.h>
#include <linux/workqueue.h>
#include <linux/jiffies.h>
+#include <linux/rcupdate.h>
+#include <linux/rculist_bl.h>
+#include <linux/bit_spinlock.h>
#include "gfs2.h"
#include "incore.h"
@@ -41,10 +44,6 @@
#define CREATE_TRACE_POINTS
#include "trace_gfs2.h"
-struct gfs2_gl_hash_bucket {
- struct hlist_head hb_list;
-};
-
struct gfs2_glock_iter {
int hash; /* hash bucket index */
struct gfs2_sbd *sdp; /* incore superblock */
@@ -54,7 +53,6 @@ struct gfs2_glock_iter {
typedef void (*glock_examiner) (struct gfs2_glock * gl);
-static int gfs2_dump_lockstate(struct gfs2_sbd *sdp);
static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl);
#define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0)
static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target);
@@ -70,57 +68,9 @@ static DEFINE_SPINLOCK(lru_lock);
#define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
#define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
-static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE];
+static struct hlist_bl_head gl_hash_table[GFS2_GL_HASH_SIZE];
static struct dentry *gfs2_root;
-/*
- * Despite what you might think, the numbers below are not arbitrary :-)
- * They are taken from the ipv4 routing hash code, which is well tested
- * and thus should be nearly optimal. Later on we might tweek the numbers
- * but for now this should be fine.
- *
- * The reason for putting the locks in a separate array from the list heads
- * is that we can have fewer locks than list heads and save memory. We use
- * the same hash function for both, but with a different hash mask.
- */
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
- defined(CONFIG_PROVE_LOCKING)
-
-#ifdef CONFIG_LOCKDEP
-# define GL_HASH_LOCK_SZ 256
-#else
-# if NR_CPUS >= 32
-# define GL_HASH_LOCK_SZ 4096
-# elif NR_CPUS >= 16
-# define GL_HASH_LOCK_SZ 2048
-# elif NR_CPUS >= 8
-# define GL_HASH_LOCK_SZ 1024
-# elif NR_CPUS >= 4
-# define GL_HASH_LOCK_SZ 512
-# else
-# define GL_HASH_LOCK_SZ 256
-# endif
-#endif
-
-/* We never want more locks than chains */
-#if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ
-# undef GL_HASH_LOCK_SZ
-# define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE
-#endif
-
-static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ];
-
-static inline rwlock_t *gl_lock_addr(unsigned int x)
-{
- return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)];
-}
-#else /* not SMP, so no spinlocks required */
-static inline rwlock_t *gl_lock_addr(unsigned int x)
-{
- return NULL;
-}
-#endif
-
/**
* gl_hash() - Turn glock number into hash bucket number
* @lock: The glock number
@@ -141,25 +91,30 @@ static unsigned int gl_hash(const struct gfs2_sbd *sdp,
return h;
}
-/**
- * glock_free() - Perform a few checks and then release struct gfs2_glock
- * @gl: The glock to release
- *
- * Also calls lock module to release its internal structure for this glock.
- *
- */
+static inline void spin_lock_bucket(unsigned int hash)
+{
+ struct hlist_bl_head *bl = &gl_hash_table[hash];
+ bit_spin_lock(0, (unsigned long *)bl);
+}
+
+static inline void spin_unlock_bucket(unsigned int hash)
+{
+ struct hlist_bl_head *bl = &gl_hash_table[hash];
+ __bit_spin_unlock(0, (unsigned long *)bl);
+}
-static void glock_free(struct gfs2_glock *gl)
+void gfs2_glock_free(struct rcu_head *rcu)
{
+ struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu);
struct gfs2_sbd *sdp = gl->gl_sbd;
- struct address_space *mapping = gfs2_glock2aspace(gl);
- struct kmem_cache *cachep = gfs2_glock_cachep;
- GLOCK_BUG_ON(gl, mapping && mapping->nrpages);
- trace_gfs2_glock_put(gl);
- if (mapping)
- cachep = gfs2_glock_aspace_cachep;
- sdp->sd_lockstruct.ls_ops->lm_put_lock(cachep, gl);
+ if (gl->gl_ops->go_flags & GLOF_ASPACE)
+ kmem_cache_free(gfs2_glock_aspace_cachep, gl);
+ else
+ kmem_cache_free(gfs2_glock_cachep, gl);
+
+ if (atomic_dec_and_test(&sdp->sd_glock_disposal))
+ wake_up(&sdp->sd_glock_wait);
}
/**
@@ -185,34 +140,49 @@ static int demote_ok(const struct gfs2_glock *gl)
{
const struct gfs2_glock_operations *glops = gl->gl_ops;
+ /* assert_spin_locked(&gl->gl_spin); */
+
if (gl->gl_state == LM_ST_UNLOCKED)
return 0;
- if (!list_empty(&gl->gl_holders))
+ if (test_bit(GLF_LFLUSH, &gl->gl_flags))
+ return 0;
+ if ((gl->gl_name.ln_type != LM_TYPE_INODE) &&
+ !list_empty(&gl->gl_holders))
return 0;
if (glops->go_demote_ok)
return glops->go_demote_ok(gl);
return 1;
}
+
/**
- * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
+ * __gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
* @gl: the glock
*
+ * If the glock is demotable, then we add it (or move it) to the end
+ * of the glock LRU list.
*/
-static void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
+static void __gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
{
- int may_reclaim;
- may_reclaim = (demote_ok(gl) &&
- (atomic_read(&gl->gl_ref) == 1 ||
- (gl->gl_name.ln_type == LM_TYPE_INODE &&
- atomic_read(&gl->gl_ref) <= 2)));
- spin_lock(&lru_lock);
- if (list_empty(&gl->gl_lru) && may_reclaim) {
+ if (demote_ok(gl)) {
+ spin_lock(&lru_lock);
+
+ if (!list_empty(&gl->gl_lru))
+ list_del_init(&gl->gl_lru);
+ else
+ atomic_inc(&lru_count);
+
list_add_tail(&gl->gl_lru, &lru_list);
- atomic_inc(&lru_count);
+ spin_unlock(&lru_lock);
}
- spin_unlock(&lru_lock);
+}
+
+void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
+{
+ spin_lock(&gl->gl_spin);
+ __gfs2_glock_schedule_for_reclaim(gl);
+ spin_unlock(&gl->gl_spin);
}
/**
@@ -227,7 +197,6 @@ void gfs2_glock_put_nolock(struct gfs2_glock *gl)
{
if (atomic_dec_and_test(&gl->gl_ref))
GLOCK_BUG_ON(gl, 1);
- gfs2_glock_schedule_for_reclaim(gl);
}
/**
@@ -236,30 +205,26 @@ void gfs2_glock_put_nolock(struct gfs2_glock *gl)
*
*/
-int gfs2_glock_put(struct gfs2_glock *gl)
+void gfs2_glock_put(struct gfs2_glock *gl)
{
- int rv = 0;
+ struct gfs2_sbd *sdp = gl->gl_sbd;
+ struct address_space *mapping = gfs2_glock2aspace(gl);
- write_lock(gl_lock_addr(gl->gl_hash));
- if (atomic_dec_and_lock(&gl->gl_ref, &lru_lock)) {
- hlist_del(&gl->gl_list);
+ if (atomic_dec_and_test(&gl->gl_ref)) {
+ spin_lock_bucket(gl->gl_hash);
+ hlist_bl_del_rcu(&gl->gl_list);
+ spin_unlock_bucket(gl->gl_hash);
+ spin_lock(&lru_lock);
if (!list_empty(&gl->gl_lru)) {
list_del_init(&gl->gl_lru);
atomic_dec(&lru_count);
}
spin_unlock(&lru_lock);
- write_unlock(gl_lock_addr(gl->gl_hash));
GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
- glock_free(gl);
- rv = 1;
- goto out;
+ GLOCK_BUG_ON(gl, mapping && mapping->nrpages);
+ trace_gfs2_glock_put(gl);
+ sdp->sd_lockstruct.ls_ops->lm_put_lock(gl);
}
- spin_lock(&gl->gl_spin);
- gfs2_glock_schedule_for_reclaim(gl);
- spin_unlock(&gl->gl_spin);
- write_unlock(gl_lock_addr(gl->gl_hash));
-out:
- return rv;
}
/**
@@ -275,17 +240,15 @@ static struct gfs2_glock *search_bucket(unsigned int hash,
const struct lm_lockname *name)
{
struct gfs2_glock *gl;
- struct hlist_node *h;
+ struct hlist_bl_node *h;
- hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) {
+ hlist_bl_for_each_entry_rcu(gl, h, &gl_hash_table[hash], gl_list) {
if (!lm_name_equal(&gl->gl_name, name))
continue;
if (gl->gl_sbd != sdp)
continue;
-
- atomic_inc(&gl->gl_ref);
-
- return gl;
+ if (atomic_inc_not_zero(&gl->gl_ref))
+ return gl;
}
return NULL;
@@ -743,10 +706,11 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
struct gfs2_glock *gl, *tmp;
unsigned int hash = gl_hash(sdp, &name);
struct address_space *mapping;
+ struct kmem_cache *cachep;
- read_lock(gl_lock_addr(hash));
+ rcu_read_lock();
gl = search_bucket(hash, sdp, &name);
- read_unlock(gl_lock_addr(hash));
+ rcu_read_unlock();
*glp = gl;
if (gl)
@@ -755,9 +719,10 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
return -ENOENT;
if (glops->go_flags & GLOF_ASPACE)
- gl = kmem_cache_alloc(gfs2_glock_aspace_cachep, GFP_KERNEL);
+ cachep = gfs2_glock_aspace_cachep;
else
- gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL);
+ cachep = gfs2_glock_cachep;
+ gl = kmem_cache_alloc(cachep, GFP_KERNEL);
if (!gl)
return -ENOMEM;
@@ -790,15 +755,15 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
mapping->writeback_index = 0;
}
- write_lock(gl_lock_addr(hash));
+ spin_lock_bucket(hash);
tmp = search_bucket(hash, sdp, &name);
if (tmp) {
- write_unlock(gl_lock_addr(hash));
- glock_free(gl);
+ spin_unlock_bucket(hash);
+ kmem_cache_free(cachep, gl);
gl = tmp;
} else {
- hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list);
- write_unlock(gl_lock_addr(hash));
+ hlist_bl_add_head_rcu(&gl->gl_list, &gl_hash_table[hash]);
+ spin_unlock_bucket(hash);
}
*glp = gl;
@@ -1113,6 +1078,7 @@ void gfs2_glock_dq(struct gfs2_holder *gh)
!test_bit(GLF_DEMOTE, &gl->gl_flags))
fast_path = 1;
}
+ __gfs2_glock_schedule_for_reclaim(gl);
trace_gfs2_glock_queue(gh, 0);
spin_unlock(&gl->gl_spin);
if (likely(fast_path))
@@ -1440,42 +1406,30 @@ static struct shrinker glock_shrinker = {
* @sdp: the filesystem
* @bucket: the bucket
*
- * Returns: 1 if the bucket has entries
*/
-static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp,
+static void examine_bucket(glock_examiner examiner, const struct gfs2_sbd *sdp,
unsigned int hash)
{
- struct gfs2_glock *gl, *prev = NULL;
- int has_entries = 0;
- struct hlist_head *head = &gl_hash_table[hash].hb_list;
+ struct gfs2_glock *gl;
+ struct hlist_bl_head *head = &gl_hash_table[hash];
+ struct hlist_bl_node *pos;
- read_lock(gl_lock_addr(hash));
- /* Can't use hlist_for_each_entry - don't want prefetch here */
- if (hlist_empty(head))
- goto out;
- gl = list_entry(head->first, struct gfs2_glock, gl_list);
- while(1) {
- if (!sdp || gl->gl_sbd == sdp) {
- gfs2_glock_hold(gl);
- read_unlock(gl_lock_addr(hash));
- if (prev)
- gfs2_glock_put(prev);
- prev = gl;
+ rcu_read_lock();
+ hlist_bl_for_each_entry_rcu(gl, pos, head, gl_list) {
+ if ((gl->gl_sbd == sdp) && atomic_read(&gl->gl_ref))
examiner(gl);
- has_entries = 1;
- read_lock(gl_lock_addr(hash));
- }
- if (gl->gl_list.next == NULL)
- break;
- gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list);
}
-out:
- read_unlock(gl_lock_addr(hash));
- if (prev)
- gfs2_glock_put(prev);
+ rcu_read_unlock();
cond_resched();
- return has_entries;
+}
+
+static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp)
+{
+ unsigned x;
+
+ for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
+ examine_bucket(examiner, sdp, x);
}
@@ -1529,10 +1483,21 @@ static void clear_glock(struct gfs2_glock *gl)
void gfs2_glock_thaw(struct gfs2_sbd *sdp)
{
- unsigned x;
+ glock_hash_walk(thaw_glock, sdp);
+}
- for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
- examine_bucket(thaw_glock, sdp, x);
+static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
+{
+ int ret;
+ spin_lock(&gl->gl_spin);
+ ret = __dump_glock(seq, gl);
+ spin_unlock(&gl->gl_spin);
+ return ret;
+}
+
+static void dump_glock_func(struct gfs2_glock *gl)
+{
+ dump_glock(NULL, gl);
}
/**
@@ -1545,13 +1510,10 @@ void gfs2_glock_thaw(struct gfs2_sbd *sdp)
void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
{
- unsigned int x;
-
- for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
- examine_bucket(clear_glock, sdp, x);
+ glock_hash_walk(clear_glock, sdp);
flush_workqueue(glock_workqueue);
wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0);
- gfs2_dump_lockstate(sdp);
+ glock_hash_walk(dump_glock_func, sdp);
}
void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
@@ -1717,66 +1679,15 @@ out:
return error;
}
-static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
-{
- int ret;
- spin_lock(&gl->gl_spin);
- ret = __dump_glock(seq, gl);
- spin_unlock(&gl->gl_spin);
- return ret;
-}
-
-/**
- * gfs2_dump_lockstate - print out the current lockstate
- * @sdp: the filesystem
- * @ub: the buffer to copy the information into
- *
- * If @ub is NULL, dump the lockstate to the console.
- *
- */
-
-static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
-{
- struct gfs2_glock *gl;
- struct hlist_node *h;
- unsigned int x;
- int error = 0;
-
- for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
-
- read_lock(gl_lock_addr(x));
-
- hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) {
- if (gl->gl_sbd != sdp)
- continue;
-
- error = dump_glock(NULL, gl);
- if (error)
- break;
- }
-
- read_unlock(gl_lock_addr(x));
-
- if (error)
- break;
- }
-
- return error;
-}
int __init gfs2_glock_init(void)
{
unsigned i;
for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
- INIT_HLIST_HEAD(&gl_hash_table[i].hb_list);
- }
-#ifdef GL_HASH_LOCK_SZ
- for(i = 0; i < GL_HASH_LOCK_SZ; i++) {
- rwlock_init(&gl_hash_locks[i]);
+ INIT_HLIST_BL_HEAD(&gl_hash_table[i]);
}
-#endif
glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM |
WQ_HIGHPRI | WQ_FREEZEABLE, 0);
@@ -1802,62 +1713,54 @@ void gfs2_glock_exit(void)
destroy_workqueue(gfs2_delete_workqueue);
}
+static inline struct gfs2_glock *glock_hash_chain(unsigned hash)
+{
+ return hlist_bl_entry(hlist_bl_first_rcu(&gl_hash_table[hash]),
+ struct gfs2_glock, gl_list);
+}
+
+static inline struct gfs2_glock *glock_hash_next(struct gfs2_glock *gl)
+{
+ return hlist_bl_entry(rcu_dereference_raw(gl->gl_list.next),
+ struct gfs2_glock, gl_list);
+}
+
static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
{
struct gfs2_glock *gl;
-restart:
- read_lock(gl_lock_addr(gi->hash));
- gl = gi->gl;
- if (gl) {
- gi->gl = hlist_entry(gl->gl_list.next,
- struct gfs2_glock, gl_list);
- } else {
- gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
- struct gfs2_glock, gl_list);
- }
- if (gi->gl)
- gfs2_glock_hold(gi->gl);
- read_unlock(gl_lock_addr(gi->hash));
- if (gl)
- gfs2_glock_put(gl);
- while (gi->gl == NULL) {
- gi->hash++;
- if (gi->hash >= GFS2_GL_HASH_SIZE)
- return 1;
- read_lock(gl_lock_addr(gi->hash));
- gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
- struct gfs2_glock, gl_list);
- if (gi->gl)
- gfs2_glock_hold(gi->gl);
- read_unlock(gl_lock_addr(gi->hash));
- }
-
- if (gi->sdp != gi->gl->gl_sbd)
- goto restart;
+ do {
+ gl = gi->gl;
+ if (gl) {
+ gi->gl = glock_hash_next(gl);
+ } else {
+ gi->gl = glock_hash_chain(gi->hash);
+ }
+ while (gi->gl == NULL) {
+ gi->hash++;
+ if (gi->hash >= GFS2_GL_HASH_SIZE) {
+ rcu_read_unlock();
+ return 1;
+ }
+ gi->gl = glock_hash_chain(gi->hash);
+ }
+ /* Skip entries for other sb and dead entries */
+ } while (gi->sdp != gi->gl->gl_sbd || atomic_read(&gi->gl->gl_ref) == 0);
return 0;
}
-static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi)
-{
- if (gi->gl)
- gfs2_glock_put(gi->gl);
- gi->gl = NULL;
-}
-
static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
{
struct gfs2_glock_iter *gi = seq->private;
loff_t n = *pos;
gi->hash = 0;
+ rcu_read_lock();
do {
- if (gfs2_glock_iter_next(gi)) {
- gfs2_glock_iter_free(gi);
+ if (gfs2_glock_iter_next(gi))
return NULL;
- }
} while (n--);
return gi->gl;
@@ -1870,10 +1773,8 @@ static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
(*pos)++;
- if (gfs2_glock_iter_next(gi)) {
- gfs2_glock_iter_free(gi);
+ if (gfs2_glock_iter_next(gi))
return NULL;
- }
return gi->gl;
}
@@ -1881,7 +1782,10 @@ static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
{
struct gfs2_glock_iter *gi = seq->private;
- gfs2_glock_iter_free(gi);
+
+ if (gi->gl)
+ rcu_read_unlock();
+ gi->gl = NULL;
}
static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
diff --git a/fs/gfs2/glock.h b/fs/gfs2/glock.h
index 691851c..afa8bfe 100644
--- a/fs/gfs2/glock.h
+++ b/fs/gfs2/glock.h
@@ -118,7 +118,7 @@ struct lm_lockops {
int (*lm_mount) (struct gfs2_sbd *sdp, const char *fsname);
void (*lm_unmount) (struct gfs2_sbd *sdp);
void (*lm_withdraw) (struct gfs2_sbd *sdp);
- void (*lm_put_lock) (struct kmem_cache *cachep, struct gfs2_glock *gl);
+ void (*lm_put_lock) (struct gfs2_glock *gl);
int (*lm_lock) (struct gfs2_glock *gl, unsigned int req_state,
unsigned int flags);
void (*lm_cancel) (struct gfs2_glock *gl);
@@ -174,7 +174,7 @@ int gfs2_glock_get(struct gfs2_sbd *sdp,
int create, struct gfs2_glock **glp);
void gfs2_glock_hold(struct gfs2_glock *gl);
void gfs2_glock_put_nolock(struct gfs2_glock *gl);
-int gfs2_glock_put(struct gfs2_glock *gl);
+void gfs2_glock_put(struct gfs2_glock *gl);
void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
struct gfs2_holder *gh);
void gfs2_holder_reinit(unsigned int state, unsigned flags,
@@ -223,25 +223,22 @@ static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
return error;
}
-/* Lock Value Block functions */
-
-int gfs2_lvb_hold(struct gfs2_glock *gl);
-void gfs2_lvb_unhold(struct gfs2_glock *gl);
-
-void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
-void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
-void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
-void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
-void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
-void gfs2_glock_thaw(struct gfs2_sbd *sdp);
-
-int __init gfs2_glock_init(void);
-void gfs2_glock_exit(void);
-
-int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
-void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
-int gfs2_register_debugfs(void);
-void gfs2_unregister_debugfs(void);
+extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
+extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
+extern void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
+extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
+extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
+extern void gfs2_glock_thaw(struct gfs2_sbd *sdp);
+extern void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
+extern void gfs2_glock_free(struct rcu_head *rcu);
+
+extern int __init gfs2_glock_init(void);
+extern void gfs2_glock_exit(void);
+
+extern int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
+extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
+extern int gfs2_register_debugfs(void);
+extern void gfs2_unregister_debugfs(void);
extern const struct lm_lockops gfs2_dlm_ops;
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index 263561b..ac5fac9 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -206,8 +206,17 @@ static void inode_go_inval(struct gfs2_glock *gl, int flags)
static int inode_go_demote_ok(const struct gfs2_glock *gl)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
+ struct gfs2_holder *gh;
+
if (sdp->sd_jindex == gl->gl_object || sdp->sd_rindex == gl->gl_object)
return 0;
+
+ if (!list_empty(&gl->gl_holders)) {
+ gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
+ if (gh->gh_list.next != &gl->gl_holders)
+ return 0;
+ }
+
return 1;
}
@@ -272,19 +281,6 @@ static int inode_go_dump(struct seq_file *seq, const struct gfs2_glock *gl)
}
/**
- * rgrp_go_demote_ok - Check to see if it's ok to unlock a RG's glock
- * @gl: the glock
- *
- * Returns: 1 if it's ok
- */
-
-static int rgrp_go_demote_ok(const struct gfs2_glock *gl)
-{
- const struct address_space *mapping = (const struct address_space *)(gl + 1);
- return !mapping->nrpages;
-}
-
-/**
* rgrp_go_lock - operation done after an rgrp lock is locked by
* a first holder on this node.
* @gl: the glock
@@ -410,7 +406,6 @@ const struct gfs2_glock_operations gfs2_inode_glops = {
const struct gfs2_glock_operations gfs2_rgrp_glops = {
.go_xmote_th = rgrp_go_sync,
.go_inval = rgrp_go_inval,
- .go_demote_ok = rgrp_go_demote_ok,
.go_lock = rgrp_go_lock,
.go_unlock = rgrp_go_unlock,
.go_dump = gfs2_rgrp_dump,
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index a79790c..720c1e6 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -15,6 +15,8 @@
#include <linux/workqueue.h>
#include <linux/dlm.h>
#include <linux/buffer_head.h>
+#include <linux/rcupdate.h>
+#include <linux/rculist_bl.h>
#define DIO_WAIT 0x00000010
#define DIO_METADATA 0x00000020
@@ -201,7 +203,7 @@ enum {
};
struct gfs2_glock {
- struct hlist_node gl_list;
+ struct hlist_bl_node gl_list;
unsigned long gl_flags; /* GLF_... */
struct lm_lockname gl_name;
atomic_t gl_ref;
@@ -234,6 +236,7 @@ struct gfs2_glock {
atomic_t gl_ail_count;
struct delayed_work gl_work;
struct work_struct gl_delete;
+ struct rcu_head gl_rcu;
};
#define GFS2_MIN_LVB_SIZE 32 /* Min size of LVB that gfs2 supports */
diff --git a/fs/gfs2/lock_dlm.c b/fs/gfs2/lock_dlm.c
index 6e493ae..c80485c 100644
--- a/fs/gfs2/lock_dlm.c
+++ b/fs/gfs2/lock_dlm.c
@@ -22,7 +22,6 @@ static void gdlm_ast(void *arg)
{
struct gfs2_glock *gl = arg;
unsigned ret = gl->gl_state;
- struct gfs2_sbd *sdp = gl->gl_sbd;
BUG_ON(gl->gl_lksb.sb_flags & DLM_SBF_DEMOTED);
@@ -31,12 +30,7 @@ static void gdlm_ast(void *arg)
switch (gl->gl_lksb.sb_status) {
case -DLM_EUNLOCK: /* Unlocked, so glock can be freed */
- if (gl->gl_ops->go_flags & GLOF_ASPACE)
- kmem_cache_free(gfs2_glock_aspace_cachep, gl);
- else
- kmem_cache_free(gfs2_glock_cachep, gl);
- if (atomic_dec_and_test(&sdp->sd_glock_disposal))
- wake_up(&sdp->sd_glock_wait);
+ call_rcu(&gl->gl_rcu, gfs2_glock_free);
return;
case -DLM_ECANCEL: /* Cancel while getting lock */
ret |= LM_OUT_CANCELED;
@@ -164,16 +158,14 @@ static int gdlm_lock(struct gfs2_glock *gl, unsigned int req_state,
GDLM_STRNAME_BYTES - 1, 0, gdlm_ast, gl, gdlm_bast);
}
-static void gdlm_put_lock(struct kmem_cache *cachep, struct gfs2_glock *gl)
+static void gdlm_put_lock(struct gfs2_glock *gl)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
struct lm_lockstruct *ls = &sdp->sd_lockstruct;
int error;
if (gl->gl_lksb.sb_lkid == 0) {
- kmem_cache_free(cachep, gl);
- if (atomic_dec_and_test(&sdp->sd_glock_disposal))
- wake_up(&sdp->sd_glock_wait);
+ call_rcu(&gl->gl_rcu, gfs2_glock_free);
return;
}
diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index bf33f82..11a73ef 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -91,7 +91,8 @@ static void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
}
bd->bd_ail = ai;
list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
- clear_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
+ if (test_and_clear_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags))
+ gfs2_glock_schedule_for_reclaim(bd->bd_gl);
trace_gfs2_pin(bd, 0);
gfs2_log_unlock(sdp);
unlock_buffer(bh);
diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
index ebef7ab..d850004 100644
--- a/fs/gfs2/main.c
+++ b/fs/gfs2/main.c
@@ -14,6 +14,8 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/gfs2_ondisk.h>
+#include <linux/rcupdate.h>
+#include <linux/rculist_bl.h>
#include <asm/atomic.h>
#include "gfs2.h"
@@ -45,7 +47,7 @@ static void gfs2_init_glock_once(void *foo)
{
struct gfs2_glock *gl = foo;
- INIT_HLIST_NODE(&gl->gl_list);
+ INIT_HLIST_BL_NODE(&gl->gl_list);
spin_lock_init(&gl->gl_spin);
INIT_LIST_HEAD(&gl->gl_holders);
INIT_LIST_HEAD(&gl->gl_lru);
@@ -198,6 +200,8 @@ static void __exit exit_gfs2_fs(void)
unregister_filesystem(&gfs2meta_fs_type);
destroy_workqueue(gfs_recovery_wq);
+ rcu_barrier();
+
kmem_cache_destroy(gfs2_quotad_cachep);
kmem_cache_destroy(gfs2_rgrpd_cachep);
kmem_cache_destroy(gfs2_bufdata_cachep);
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 777927c..a39c103 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -928,12 +928,9 @@ static const match_table_t nolock_tokens = {
{ Opt_err, NULL },
};
-static void nolock_put_lock(struct kmem_cache *cachep, struct gfs2_glock *gl)
+static void nolock_put_lock(struct gfs2_glock *gl)
{
- struct gfs2_sbd *sdp = gl->gl_sbd;
- kmem_cache_free(cachep, gl);
- if (atomic_dec_and_test(&sdp->sd_glock_disposal))
- wake_up(&sdp->sd_glock_wait);
+ call_rcu(&gl->gl_rcu, gfs2_glock_free);
}
static const struct lm_lockops nolock_ops = {
--
1.7.4
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