The only reader which use state_lock is dqget(), and is it serialized
with quota_disable via SRCU. And state_lock doesn't guaranties anything
for that case. All methods which modify quota flags already protected by
dqonoff_mutex. Get rid of useless state_lock.
Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>
---
fs/quota/dquot.c | 24 ++----------------------
1 files changed, 2 insertions(+), 22 deletions(-)
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 78e48f3..a1efacd 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -86,12 +86,9 @@
* dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and
* also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes.
* i_blocks and i_bytes updates itself are guarded by i_lock acquired directly
- * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects
- * modifications of quota state (on quotaon and quotaoff) and readers who care
- * about latest values take it as well.
+ * in inode_add_bytes() and inode_sub_bytes().
*
- * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock,
- * dq_list_lock > dq_state_lock
+ * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock.
*
* Note that some things (eg. sb pointer, type, id) doesn't change during
* the life of the dquot structure and so needn't to be protected by a lock
@@ -128,7 +125,6 @@
*/
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);
@@ -827,14 +823,10 @@ struct dquot *dqget(struct super_block *sb, unsigned int id, int type)
rcu_read_unlock();
we_slept:
spin_lock(&dq_list_lock);
- spin_lock(&dq_state_lock);
if (!sb_has_quota_active(sb, type)) {
- spin_unlock(&dq_state_lock);
spin_unlock(&dq_list_lock);
goto out;
}
- spin_unlock(&dq_state_lock);
-
dquot = find_dquot(hashent, sb, id, type);
if (!dquot) {
if (!empty) {
@@ -2022,24 +2014,19 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags)
continue;
if (flags & DQUOT_SUSPENDED) {
- spin_lock(&dq_state_lock);
qctl->flags |=
dquot_state_flag(DQUOT_SUSPENDED, cnt);
- spin_unlock(&dq_state_lock);
} else {
- spin_lock(&dq_state_lock);
qctl->flags &= ~dquot_state_flag(flags, cnt);
/* Turning off suspended quotas? */
if (!sb_has_quota_loaded(sb, cnt) &&
sb_has_quota_suspended(sb, cnt)) {
qctl->flags &= ~dquot_state_flag(
DQUOT_SUSPENDED, cnt);
- spin_unlock(&dq_state_lock);
iput(dqopt->files[cnt]);
dqopt->files[cnt] = NULL;
continue;
}
- spin_unlock(&dq_state_lock);
}
/* We still have to keep quota loaded? */
@@ -2235,10 +2222,7 @@ 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);
dqctl(sb)->flags |= dquot_state_flag(flags, type);
- spin_unlock(&dq_state_lock);
-
add_dquot_ref(sb, type);
mutex_unlock(&dqctl(sb)->dqonoff_mutex);
@@ -2290,12 +2274,10 @@ int dquot_resume(struct super_block *sb, int type)
}
inode = qctl->dq_opt->files[cnt];
qctl->dq_opt->files[cnt] = NULL;
- spin_lock(&dq_state_lock);
flags = qctl->flags & dquot_state_flag(DQUOT_USAGE_ENABLED |
DQUOT_LIMITS_ENABLED,
cnt);
qctl->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt);
- spin_unlock(&dq_state_lock);
mutex_unlock(&qctl->dqonoff_mutex);
flags = dquot_generic_flag(flags, cnt);
@@ -2369,9 +2351,7 @@ int dquot_enable(struct inode *inode, int type, int format_id,
ret = -EBUSY;
goto out_lock;
}
- spin_lock(&dq_state_lock);
qctl->flags |= dquot_state_flag(flags, type);
- spin_unlock(&dq_state_lock);
out_lock:
mutex_unlock(&qctl->dqonoff_mutex);
return ret;
--
1.6.5.2
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