We need dqio_sem held just for reading when calling ->read_dqblk() in
dquot_acquire(). Also dqio_sem is not needed when manipulating dquot
flags (those are protected by dq_lock) so acquire and release it closer
to the place where it is needed. This reduces lock hold time and will
make locking changes easier.
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/quota/dquot.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 29d447598642..21358f31923d 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -406,9 +406,11 @@ int dquot_acquire(struct dquot *dquot)
struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
mutex_lock(&dquot->dq_lock);
- down_write(&dqopt->dqio_sem);
- if (!test_bit(DQ_READ_B, &dquot->dq_flags))
+ if (!test_bit(DQ_READ_B, &dquot->dq_flags)) {
+ down_read(&dqopt->dqio_sem);
ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot);
+ up_read(&dqopt->dqio_sem);
+ }
if (ret < 0)
goto out_iolock;
/* Make sure flags update is visible after dquot has been filled */
@@ -416,12 +418,14 @@ int dquot_acquire(struct dquot *dquot)
set_bit(DQ_READ_B, &dquot->dq_flags);
/* Instantiate dquot if needed */
if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
+ down_write(&dqopt->dqio_sem);
ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
/* Write the info if needed */
if (info_dirty(&dqopt->info[dquot->dq_id.type])) {
ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info(
dquot->dq_sb, dquot->dq_id.type);
}
+ up_write(&dqopt->dqio_sem);
if (ret < 0)
goto out_iolock;
if (ret2 < 0) {
@@ -436,7 +440,6 @@ int dquot_acquire(struct dquot *dquot)
smp_mb__before_atomic();
set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
out_iolock:
- up_write(&dqopt->dqio_sem);
mutex_unlock(&dquot->dq_lock);
return ret;
}
--
2.12.3
