* sure they cannot race with quotaon which first sets S_NOQUOTA flag and
* then drops all pointers to dquots from an inode.
*
- * Each dquot has its dq_lock mutex. Locked dquots might not be referenced
- * from inodes (dquot_alloc_space() and such don't check the dq_lock).
- * Currently dquot is locked only when it is being read to memory (or space for
- * it is being allocated) on the first dqget() and when it is being released on
- * the last dqput(). The allocation and release oparations are serialized by
- * the dq_lock and by checking the use count in dquot_release(). Write
- * operations on dquots don't hold dq_lock as they copy data under dq_data_lock
- * spinlock to internal buffers before writing.
+ * Each dquot has its dq_lock mutex. Dquot is locked when it is being read to
+ * memory (or space for it is being allocated) on the first dqget(), when it is
+ * being written out, and when it is being released on the last dqput(). The
+ * allocation and release operations are serialized by the dq_lock and by
+ * checking the use count in dquot_release().
*
* Lock ordering (including related VFS locks) is the following:
- * s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_mutex
+ * s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_sem
*/
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
EXPORT_SYMBOL(dq_data_lock);
DEFINE_STATIC_SRCU(dquot_srcu);
+static DECLARE_WAIT_QUEUE_HEAD(dquot_ref_wq);
+
void __quota_error(struct super_block *sb, const char *func,
const char *fmt, ...)
{
{
int ret = 1;
+ if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
+ return 0;
+
+ if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY)
+ return test_and_set_bit(DQ_MOD_B, &dquot->dq_flags);
+
/* If quota is dirty already, we don't have to acquire dq_list_lock */
if (test_bit(DQ_MOD_B, &dquot->dq_flags))
return 1;
dqput(dquot[cnt]);
}
-/* This function needs dq_list_lock */
static inline int clear_dquot_dirty(struct dquot *dquot)
{
- if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags))
+ if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY)
+ return test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags);
+
+ spin_lock(&dq_list_lock);
+ if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) {
+ spin_unlock(&dq_list_lock);
return 0;
+ }
list_del_init(&dquot->dq_dirty);
+ spin_unlock(&dq_list_lock);
return 1;
}
void mark_info_dirty(struct super_block *sb, int type)
{
- set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags);
+ spin_lock(&dq_data_lock);
+ sb_dqopt(sb)->info[type].dqi_flags |= DQF_INFO_DIRTY;
+ spin_unlock(&dq_data_lock);
}
EXPORT_SYMBOL(mark_info_dirty);
struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
mutex_lock(&dquot->dq_lock);
- mutex_lock(&dqopt->dqio_mutex);
if (!test_bit(DQ_READ_B, &dquot->dq_flags))
ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot);
if (ret < 0)
smp_mb__before_atomic();
set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
out_iolock:
- mutex_unlock(&dqopt->dqio_mutex);
mutex_unlock(&dquot->dq_lock);
return ret;
}
int ret = 0;
struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
- mutex_lock(&dqopt->dqio_mutex);
- spin_lock(&dq_list_lock);
- if (!clear_dquot_dirty(dquot)) {
- spin_unlock(&dq_list_lock);
- goto out_sem;
- }
- spin_unlock(&dq_list_lock);
+ mutex_lock(&dquot->dq_lock);
+ if (!clear_dquot_dirty(dquot))
+ goto out_lock;
/* Inactive dquot can be only if there was error during read/init
* => we have better not writing it */
if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot);
else
ret = -EIO;
-out_sem:
- mutex_unlock(&dqopt->dqio_mutex);
+out_lock:
+ mutex_unlock(&dquot->dq_lock);
return ret;
}
EXPORT_SYMBOL(dquot_commit);
/* Check whether we are not racing with some other dqget() */
if (atomic_read(&dquot->dq_count) > 1)
goto out_dqlock;
- mutex_lock(&dqopt->dqio_mutex);
if (dqopt->ops[dquot->dq_id.type]->release_dqblk) {
ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot);
/* Write the info */
ret = ret2;
}
clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
- mutex_unlock(&dqopt->dqio_mutex);
out_dqlock:
mutex_unlock(&dquot->dq_lock);
return ret;
continue;
/* Wait for dquot users */
if (atomic_read(&dquot->dq_count)) {
- DEFINE_WAIT(wait);
-
dqgrab(dquot);
- prepare_to_wait(&dquot->dq_wait_unused, &wait,
- TASK_UNINTERRUPTIBLE);
spin_unlock(&dq_list_lock);
- /* Once dqput() wakes us up, we know it's time to free
+ /*
+ * Once dqput() wakes us up, we know it's time to free
* the dquot.
* IMPORTANT: we rely on the fact that there is always
* at most one process waiting for dquot to free.
* Otherwise dq_count would be > 1 and we would never
* wake up.
*/
- if (atomic_read(&dquot->dq_count) > 1)
- schedule();
- finish_wait(&dquot->dq_wait_unused, &wait);
+ wait_event(dquot_ref_wq,
+ atomic_read(&dquot->dq_count) == 1);
dqput(dquot);
/* At this moment dquot() need not exist (it could be
* reclaimed by prune_dqcache(). Hence we must
while (!list_empty(dirty)) {
dquot = list_first_entry(dirty, struct dquot,
dq_dirty);
- /* Dirty and inactive can be only bad dquot... */
- if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
- clear_dquot_dirty(dquot);
- continue;
- }
+
+ WARN_ON(!test_bit(DQ_ACTIVE_B, &dquot->dq_flags));
+
/* Now we have active dquot from which someone is
* holding reference so we can safely just increase
* use count */
/* Releasing dquot during quotaoff phase? */
if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) &&
atomic_read(&dquot->dq_count) == 1)
- wake_up(&dquot->dq_wait_unused);
+ wake_up(&dquot_ref_wq);
spin_unlock(&dq_list_lock);
return;
}
/* Need to release dquot? */
- if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) {
+ if (dquot_dirty(dquot)) {
spin_unlock(&dq_list_lock);
/* Commit dquot before releasing */
ret = dquot->dq_sb->dq_op->write_dquot(dquot);
* We clear dirty bit anyway, so that we avoid
* infinite loop here
*/
- spin_lock(&dq_list_lock);
clear_dquot_dirty(dquot);
- spin_unlock(&dq_list_lock);
}
goto we_slept;
}
- /* Clear flag in case dquot was inactive (something bad happened) */
- clear_dquot_dirty(dquot);
if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
spin_unlock(&dq_list_lock);
dquot->dq_sb->dq_op->release_dquot(dquot);
INIT_LIST_HEAD(&dquot->dq_inuse);
INIT_HLIST_NODE(&dquot->dq_hash);
INIT_LIST_HEAD(&dquot->dq_dirty);
- init_waitqueue_head(&dquot->dq_wait_unused);
dquot->dq_sb = sb;
dquot->dq_id = make_kqid_invalid(type);
atomic_set(&dquot->dq_count, 1);
*/
int dquot_commit_info(struct super_block *sb, int type)
{
- int ret;
struct quota_info *dqopt = sb_dqopt(sb);
- mutex_lock(&dqopt->dqio_mutex);
- ret = dqopt->ops[type]->write_file_info(sb, type);
- mutex_unlock(&dqopt->dqio_mutex);
- return ret;
+ return dqopt->ops[type]->write_file_info(sb, type);
}
EXPORT_SYMBOL(dquot_commit_info);
int dquot_get_next_id(struct super_block *sb, struct kqid *qid)
{
struct quota_info *dqopt = sb_dqopt(sb);
- int err;
if (!sb_has_quota_active(sb, qid->type))
return -ESRCH;
if (!dqopt->ops[qid->type]->get_next_id)
return -ENOSYS;
- mutex_lock(&dqopt->dqio_mutex);
- err = dqopt->ops[qid->type]->get_next_id(sb, qid);
- mutex_unlock(&dqopt->dqio_mutex);
- return err;
+ return dqopt->ops[qid->type]->get_next_id(sb, qid);
}
EXPORT_SYMBOL(dquot_get_next_id);
dqopt->info[type].dqi_format = fmt;
dqopt->info[type].dqi_fmt_id = format_id;
INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list);
- mutex_lock(&dqopt->dqio_mutex);
error = dqopt->ops[type]->read_file_info(sb, type);
- if (error < 0) {
- mutex_unlock(&dqopt->dqio_mutex);
+ if (error < 0)
goto out_file_init;
- }
- if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
+ if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) {
+ spin_lock(&dq_data_lock);
dqopt->info[type].dqi_flags |= DQF_SYS_FILE;
- mutex_unlock(&dqopt->dqio_mutex);
+ spin_unlock(&dq_data_lock);
+ }
spin_lock(&dq_state_lock);
dqopt->flags |= dquot_state_flag(flags, type);
spin_unlock(&dq_state_lock);
git.samba.org / sfrench / cifs-2.6.git / blobdiff