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-rw-r--r--fs/gfs2/glock.c83
-rw-r--r--fs/gfs2/glock.h2
-rw-r--r--fs/gfs2/glops.c4
-rw-r--r--fs/gfs2/incore.h5
-rw-r--r--include/linux/lockref.h6
-rw-r--r--lib/lockref.c1
6 files changed, 52 insertions, 49 deletions
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index c2f41b4..e66a800 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -31,6 +31,7 @@
#include <linux/bit_spinlock.h>
#include <linux/percpu.h>
#include <linux/list_sort.h>
+#include <linux/lockref.h>
#include "gfs2.h"
#include "incore.h"
@@ -129,10 +130,10 @@ void gfs2_glock_free(struct gfs2_glock *gl)
*
*/
-void gfs2_glock_hold(struct gfs2_glock *gl)
+static void gfs2_glock_hold(struct gfs2_glock *gl)
{
- GLOCK_BUG_ON(gl, atomic_read(&gl->gl_ref) == 0);
- atomic_inc(&gl->gl_ref);
+ GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
+ lockref_get(&gl->gl_lockref);
}
/**
@@ -187,20 +188,6 @@ static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl)
}
/**
- * gfs2_glock_put_nolock() - Decrement reference count on glock
- * @gl: The glock to put
- *
- * This function should only be used if the caller has its own reference
- * to the glock, in addition to the one it is dropping.
- */
-
-void gfs2_glock_put_nolock(struct gfs2_glock *gl)
-{
- if (atomic_dec_and_test(&gl->gl_ref))
- GLOCK_BUG_ON(gl, 1);
-}
-
-/**
* gfs2_glock_put() - Decrement reference count on glock
* @gl: The glock to put
*
@@ -211,17 +198,22 @@ void gfs2_glock_put(struct gfs2_glock *gl)
struct gfs2_sbd *sdp = gl->gl_sbd;
struct address_space *mapping = gfs2_glock2aspace(gl);
- if (atomic_dec_and_lock(&gl->gl_ref, &lru_lock)) {
- __gfs2_glock_remove_from_lru(gl);
- spin_unlock(&lru_lock);
- spin_lock_bucket(gl->gl_hash);
- hlist_bl_del_rcu(&gl->gl_list);
- spin_unlock_bucket(gl->gl_hash);
- GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
- GLOCK_BUG_ON(gl, mapping && mapping->nrpages);
- trace_gfs2_glock_put(gl);
- sdp->sd_lockstruct.ls_ops->lm_put_lock(gl);
- }
+ if (lockref_put_or_lock(&gl->gl_lockref))
+ return;
+
+ lockref_mark_dead(&gl->gl_lockref);
+
+ spin_lock(&lru_lock);
+ __gfs2_glock_remove_from_lru(gl);
+ spin_unlock(&lru_lock);
+ spin_unlock(&gl->gl_lockref.lock);
+ spin_lock_bucket(gl->gl_hash);
+ hlist_bl_del_rcu(&gl->gl_list);
+ spin_unlock_bucket(gl->gl_hash);
+ GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
+ GLOCK_BUG_ON(gl, mapping && mapping->nrpages);
+ trace_gfs2_glock_put(gl);
+ sdp->sd_lockstruct.ls_ops->lm_put_lock(gl);
}
/**
@@ -244,7 +236,7 @@ static struct gfs2_glock *search_bucket(unsigned int hash,
continue;
if (gl->gl_sbd != sdp)
continue;
- if (atomic_inc_not_zero(&gl->gl_ref))
+ if (lockref_get_not_dead(&gl->gl_lockref))
return gl;
}
@@ -396,10 +388,11 @@ static void state_change(struct gfs2_glock *gl, unsigned int new_state)
held2 = (new_state != LM_ST_UNLOCKED);
if (held1 != held2) {
+ GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref));
if (held2)
- gfs2_glock_hold(gl);
+ gl->gl_lockref.count++;
else
- gfs2_glock_put_nolock(gl);
+ gl->gl_lockref.count--;
}
if (held1 && held2 && list_empty(&gl->gl_holders))
clear_bit(GLF_QUEUED, &gl->gl_flags);
@@ -626,9 +619,9 @@ out:
out_sched:
clear_bit(GLF_LOCK, &gl->gl_flags);
smp_mb__after_clear_bit();
- gfs2_glock_hold(gl);
+ gl->gl_lockref.count++;
if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
- gfs2_glock_put_nolock(gl);
+ gl->gl_lockref.count--;
return;
out_unlock:
@@ -754,7 +747,7 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
gl->gl_sbd = sdp;
gl->gl_flags = 0;
gl->gl_name = name;
- atomic_set(&gl->gl_ref, 1);
+ gl->gl_lockref.count = 1;
gl->gl_state = LM_ST_UNLOCKED;
gl->gl_target = LM_ST_UNLOCKED;
gl->gl_demote_state = LM_ST_EXCLUSIVE;
@@ -1356,10 +1349,10 @@ void gfs2_glock_complete(struct gfs2_glock *gl, int ret)
}
}
- spin_unlock(&gl->gl_spin);
+ gl->gl_lockref.count++;
set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
- smp_wmb();
- gfs2_glock_hold(gl);
+ spin_unlock(&gl->gl_spin);
+
if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
gfs2_glock_put(gl);
}
@@ -1404,15 +1397,19 @@ __acquires(&lru_lock)
while(!list_empty(list)) {
gl = list_entry(list->next, struct gfs2_glock, gl_lru);
list_del_init(&gl->gl_lru);
+ if (!spin_trylock(&gl->gl_spin)) {
+ list_add(&gl->gl_lru, &lru_list);
+ atomic_inc(&lru_count);
+ continue;
+ }
clear_bit(GLF_LRU, &gl->gl_flags);
- gfs2_glock_hold(gl);
spin_unlock(&lru_lock);
- spin_lock(&gl->gl_spin);
+ gl->gl_lockref.count++;
if (demote_ok(gl))
handle_callback(gl, LM_ST_UNLOCKED, 0, false);
WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags));
if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
- gfs2_glock_put_nolock(gl);
+ gl->gl_lockref.count--;
spin_unlock(&gl->gl_spin);
spin_lock(&lru_lock);
}
@@ -1493,7 +1490,7 @@ static void examine_bucket(glock_examiner examiner, const struct gfs2_sbd *sdp,
rcu_read_lock();
hlist_bl_for_each_entry_rcu(gl, pos, head, gl_list) {
- if ((gl->gl_sbd == sdp) && atomic_inc_not_zero(&gl->gl_ref))
+ if ((gl->gl_sbd == sdp) && lockref_get_not_dead(&gl->gl_lockref))
examiner(gl);
}
rcu_read_unlock();
@@ -1746,7 +1743,7 @@ int gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
state2str(gl->gl_demote_state), dtime,
atomic_read(&gl->gl_ail_count),
atomic_read(&gl->gl_revokes),
- atomic_read(&gl->gl_ref), gl->gl_hold_time);
+ (int)gl->gl_lockref.count, gl->gl_hold_time);
list_for_each_entry(gh, &gl->gl_holders, gh_list) {
error = dump_holder(seq, gh);
@@ -1902,7 +1899,7 @@ static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
gi->nhash = 0;
}
/* Skip entries for other sb and dead entries */
- } while (gi->sdp != gi->gl->gl_sbd || atomic_read(&gi->gl->gl_ref) == 0);
+ } while (gi->sdp != gi->gl->gl_sbd || __lockref_is_dead(&gl->gl_lockref));
return 0;
}
diff --git a/fs/gfs2/glock.h b/fs/gfs2/glock.h
index 69f66e3..6647d77 100644
--- a/fs/gfs2/glock.h
+++ b/fs/gfs2/glock.h
@@ -181,8 +181,6 @@ static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl)
extern int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
const struct gfs2_glock_operations *glops,
int create, struct gfs2_glock **glp);
-extern void gfs2_glock_hold(struct gfs2_glock *gl);
-extern void gfs2_glock_put_nolock(struct gfs2_glock *gl);
extern void gfs2_glock_put(struct gfs2_glock *gl);
extern void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
unsigned flags, struct gfs2_holder *gh);
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index e2e0a90..db908f6 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -525,9 +525,9 @@ static void iopen_go_callback(struct gfs2_glock *gl, bool remote)
if (gl->gl_demote_state == LM_ST_UNLOCKED &&
gl->gl_state == LM_ST_SHARED && ip) {
- gfs2_glock_hold(gl);
+ gl->gl_lockref.count++;
if (queue_work(gfs2_delete_workqueue, &gl->gl_delete) == 0)
- gfs2_glock_put_nolock(gl);
+ gl->gl_lockref.count--;
}
}
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 2ab4f8d..bb88e41 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -21,6 +21,7 @@
#include <linux/rbtree.h>
#include <linux/ktime.h>
#include <linux/percpu.h>
+#include <linux/lockref.h>
#define DIO_WAIT 0x00000010
#define DIO_METADATA 0x00000020
@@ -321,9 +322,9 @@ struct gfs2_glock {
struct gfs2_sbd *gl_sbd;
unsigned long gl_flags; /* GLF_... */
struct lm_lockname gl_name;
- atomic_t gl_ref;
- spinlock_t gl_spin;
+ struct lockref gl_lockref;
+#define gl_spin gl_lockref.lock
/* State fields protected by gl_spin */
unsigned int gl_state:2, /* Current state */
diff --git a/include/linux/lockref.h b/include/linux/lockref.h
index f279ed9..13dfd36 100644
--- a/include/linux/lockref.h
+++ b/include/linux/lockref.h
@@ -36,4 +36,10 @@ extern int lockref_put_or_lock(struct lockref *);
extern void lockref_mark_dead(struct lockref *);
extern int lockref_get_not_dead(struct lockref *);
+/* Must be called under spinlock for reliable results */
+static inline int __lockref_is_dead(const struct lockref *l)
+{
+ return ((int)l->count < 0);
+}
+
#endif /* __LINUX_LOCKREF_H */
diff --git a/lib/lockref.c b/lib/lockref.c
index e2cd2c0..8ff162f 100644
--- a/lib/lockref.c
+++ b/lib/lockref.c
@@ -136,6 +136,7 @@ void lockref_mark_dead(struct lockref *lockref)
assert_spin_locked(&lockref->lock);
lockref->count = -128;
}
+EXPORT_SYMBOL(lockref_mark_dead);
/**
* lockref_get_not_dead - Increments count unless the ref is dead
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