Currently dq_state_lock is global, which is bad for scalability.
In fact different super_blocks has no shared quota's data.
So we may simply convert global lock to per-sb lock.
Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxx>
---
fs/quota/dquot.c | 31 +++++++++++++++----------------
fs/super.c | 1 +
include/linux/quota.h | 1 +
3 files changed, 17 insertions(+), 16 deletions(-)
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index ce542e2..eddf5cf 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -128,7 +128,6 @@
*/
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
-static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock);
__cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock);
EXPORT_SYMBOL(dq_data_lock);
@@ -819,13 +818,13 @@ struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
return NULL;
we_slept:
spin_lock(&dq_list_lock);
- spin_lock(&dq_state_lock);
+ spin_lock(&sb_dqopt(sb)->dq_state_lock);
if (!sb_has_quota_active(sb, type)) {
- spin_unlock(&dq_state_lock);
+ spin_unlock(&sb_dqopt(sb)->dq_state_lock);
spin_unlock(&dq_list_lock);
goto out;
}
- spin_unlock(&dq_state_lock);
+ spin_unlock(&sb_dqopt(sb)->dq_state_lock);
dquot = find_dquot(hashent, sb, id, type);
if (!dquot) {
@@ -1918,24 +1917,24 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags)
continue;
if (flags & DQUOT_SUSPENDED) {
- spin_lock(&dq_state_lock);
+ spin_lock(&dqopt->dq_state_lock);
dqopt->flags |=
dquot_state_flag(DQUOT_SUSPENDED, cnt);
- spin_unlock(&dq_state_lock);
+ spin_unlock(&dqopt->dq_state_lock);
} else {
- spin_lock(&dq_state_lock);
+ spin_lock(&dqopt->dq_state_lock);
dqopt->flags &= ~dquot_state_flag(flags, cnt);
/* Turning off suspended quotas? */
if (!sb_has_quota_loaded(sb, cnt) &&
sb_has_quota_suspended(sb, cnt)) {
dqopt->flags &= ~dquot_state_flag(
DQUOT_SUSPENDED, cnt);
- spin_unlock(&dq_state_lock);
+ spin_unlock(&dqopt->dq_state_lock);
iput(dqopt->files[cnt]);
dqopt->files[cnt] = NULL;
continue;
}
- spin_unlock(&dq_state_lock);
+ spin_unlock(&dqopt->dq_state_lock);
}
/* We still have to keep quota loaded? */
@@ -2112,9 +2111,9 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
goto out_file_init;
}
mutex_unlock(&dqopt->dqio_mutex);
- spin_lock(&dq_state_lock);
+ spin_lock(&dqopt->dq_state_lock);
dqopt->flags |= dquot_state_flag(flags, type);
- spin_unlock(&dq_state_lock);
+ spin_unlock(&dqopt->dq_state_lock);
add_dquot_ref(sb, type);
mutex_unlock(&dqopt->dqonoff_mutex);
@@ -2159,12 +2158,12 @@ int dquot_resume(struct super_block *sb, int type)
}
inode = dqopt->files[cnt];
dqopt->files[cnt] = NULL;
- spin_lock(&dq_state_lock);
+ spin_lock(&dqopt->dq_state_lock);
flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
DQUOT_LIMITS_ENABLED,
cnt);
dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt);
- spin_unlock(&dq_state_lock);
+ spin_unlock(&dqopt->dq_state_lock);
mutex_unlock(&dqopt->dqonoff_mutex);
flags = dquot_generic_flag(flags, cnt);
@@ -2228,9 +2227,9 @@ int dquot_enable(struct inode *inode, int type, int format_id,
ret = -EBUSY;
goto out_lock;
}
- spin_lock(&dq_state_lock);
- sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);
- spin_unlock(&dq_state_lock);
+ spin_lock(&dqopt->dq_state_lock);
+ dqopt->flags |= dquot_state_flag(flags, type);
+ spin_unlock(&dqopt->dq_state_lock);
out_lock:
mutex_unlock(&dqopt->dqonoff_mutex);
return ret;
diff --git a/fs/super.c b/fs/super.c
index 8819e3a..b54cb8b 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -105,6 +105,7 @@ static struct super_block *alloc_super(struct file_system_type *type)
lockdep_set_class(&s->s_vfs_rename_mutex, &type->s_vfs_rename_key);
mutex_init(&s->s_dquot.dqio_mutex);
mutex_init(&s->s_dquot.dqonoff_mutex);
+ spin_lock_init(&s->s_dquot.dq_state_lock);
init_rwsem(&s->s_dquot.dqptr_sem);
init_waitqueue_head(&s->s_wait_unfrozen);
s->s_maxbytes = MAX_NON_LFS;
diff --git a/include/linux/quota.h b/include/linux/quota.h
index 00e1b3d..e39b01c 100644
--- a/include/linux/quota.h
+++ b/include/linux/quota.h
@@ -398,6 +398,7 @@ struct quota_info {
struct mutex dqio_mutex; /* lock device while I/O in progress */
struct mutex dqonoff_mutex; /* Serialize quotaon & quotaoff */
struct rw_semaphore dqptr_sem; /* serialize ops using quota_info struct, pointers from inode to dquots */
+ spinlock_t dq_state_lock; /* serialize quota state changes*/
struct inode *files[MAXQUOTAS]; /* inodes of quotafiles */
struct mem_dqinfo info[MAXQUOTAS]; /* Information for each quota type */
const struct quota_format_ops *ops[MAXQUOTAS]; /* Operations for each type */
--
1.6.6.1
--
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