Convert dqio_mutex to rwsem and call it dqio_sem. No functional changes
yet.
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/ext4/super.c | 13 ++++---------
fs/ocfs2/quota_global.c | 20 ++++++++++----------
fs/ocfs2/quota_local.c | 10 +++++-----
fs/quota/dquot.c | 28 ++++++++++++++--------------
fs/quota/quota_tree.c | 2 +-
fs/super.c | 2 +-
include/linux/quota.h | 2 +-
7 files changed, 36 insertions(+), 41 deletions(-)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index d61a70e2193a..4c168b90903c 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5263,18 +5263,13 @@ static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
return 0;
}
-/* Helper function for writing quotas on sync - we need to start transaction
- * before quota file is locked for write. Otherwise the are possible deadlocks:
- * Process 1 Process 2
- * ext4_create() quota_sync()
- * jbd2_journal_start() write_dquot()
- * dquot_initialize() down(dqio_mutex)
- * down(dqio_mutex) jbd2_journal_start()
- *
- */
#ifdef CONFIG_QUOTA
+/*
+ * Helper functions so that transaction is started before we acquire dqio_sem
+ * to keep correct lock ordering of transaction > dqio_sem
+ */
static inline struct inode *dquot_to_inode(struct dquot *dquot)
{
return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
index cec495a921e3..4134d557a8e5 100644
--- a/fs/ocfs2/quota_global.c
+++ b/fs/ocfs2/quota_global.c
@@ -33,7 +33,7 @@
* Locking of quotas with OCFS2 is rather complex. Here are rules that
* should be obeyed by all the functions:
* - any write of quota structure (either to local or global file) is protected
- * by dqio_mutex or dquot->dq_lock.
+ * by dqio_sem or dquot->dq_lock.
* - any modification of global quota file holds inode cluster lock, i_mutex,
* and ip_alloc_sem of the global quota file (achieved by
* ocfs2_lock_global_qf). It also has to hold qinfo_lock.
@@ -42,9 +42,9 @@
*
* A rough sketch of locking dependencies (lf = local file, gf = global file):
* Normal filesystem operation:
- * start_trans -> dqio_mutex -> write to lf
+ * start_trans -> dqio_sem -> write to lf
* Syncing of local and global file:
- * ocfs2_lock_global_qf -> start_trans -> dqio_mutex -> qinfo_lock ->
+ * ocfs2_lock_global_qf -> start_trans -> dqio_sem -> qinfo_lock ->
* write to gf
* -> write to lf
* Acquire dquot for the first time:
@@ -60,7 +60,7 @@
* Recovery:
* inode cluster lock of recovered lf
* -> read bitmaps -> ip_alloc_sem of lf
- * -> ocfs2_lock_global_qf -> start_trans -> dqio_mutex -> qinfo_lock ->
+ * -> ocfs2_lock_global_qf -> start_trans -> dqio_sem -> qinfo_lock ->
* write to gf
*/
@@ -611,7 +611,7 @@ static int ocfs2_sync_dquot_helper(struct dquot *dquot, unsigned long type)
mlog_errno(status);
goto out_ilock;
}
- mutex_lock(&sb_dqopt(sb)->dqio_mutex);
+ down_write(&sb_dqopt(sb)->dqio_sem);
status = ocfs2_sync_dquot(dquot);
if (status < 0)
mlog_errno(status);
@@ -619,7 +619,7 @@ static int ocfs2_sync_dquot_helper(struct dquot *dquot, unsigned long type)
status = ocfs2_local_write_dquot(dquot);
if (status < 0)
mlog_errno(status);
- mutex_unlock(&sb_dqopt(sb)->dqio_mutex);
+ up_write(&sb_dqopt(sb)->dqio_sem);
ocfs2_commit_trans(osb, handle);
out_ilock:
ocfs2_unlock_global_qf(oinfo, 1);
@@ -666,9 +666,9 @@ static int ocfs2_write_dquot(struct dquot *dquot)
mlog_errno(status);
goto out;
}
- mutex_lock(&sb_dqopt(dquot->dq_sb)->dqio_mutex);
+ down_write(&sb_dqopt(dquot->dq_sb)->dqio_sem);
status = ocfs2_local_write_dquot(dquot);
- mutex_unlock(&sb_dqopt(dquot->dq_sb)->dqio_mutex);
+ up_write(&sb_dqopt(dquot->dq_sb)->dqio_sem);
ocfs2_commit_trans(osb, handle);
out:
return status;
@@ -939,7 +939,7 @@ static int ocfs2_mark_dquot_dirty(struct dquot *dquot)
mlog_errno(status);
goto out_ilock;
}
- mutex_lock(&sb_dqopt(sb)->dqio_mutex);
+ down_write(&sb_dqopt(sb)->dqio_sem);
status = ocfs2_sync_dquot(dquot);
if (status < 0) {
mlog_errno(status);
@@ -948,7 +948,7 @@ static int ocfs2_mark_dquot_dirty(struct dquot *dquot)
/* Now write updated local dquot structure */
status = ocfs2_local_write_dquot(dquot);
out_dlock:
- mutex_unlock(&sb_dqopt(sb)->dqio_mutex);
+ up_write(&sb_dqopt(sb)->dqio_sem);
ocfs2_commit_trans(osb, handle);
out_ilock:
ocfs2_unlock_global_qf(oinfo, 1);
diff --git a/fs/ocfs2/quota_local.c b/fs/ocfs2/quota_local.c
index 32c5a40c1257..1311eff1c050 100644
--- a/fs/ocfs2/quota_local.c
+++ b/fs/ocfs2/quota_local.c
@@ -520,7 +520,7 @@ static int ocfs2_recover_local_quota_file(struct inode *lqinode,
mlog_errno(status);
goto out_drop_lock;
}
- mutex_lock(&sb_dqopt(sb)->dqio_mutex);
+ down_write(&sb_dqopt(sb)->dqio_sem);
spin_lock(&dq_data_lock);
/* Add usage from quota entry into quota changes
* of our node. Auxiliary variables are important
@@ -553,7 +553,7 @@ static int ocfs2_recover_local_quota_file(struct inode *lqinode,
unlock_buffer(qbh);
ocfs2_journal_dirty(handle, qbh);
out_commit:
- mutex_unlock(&sb_dqopt(sb)->dqio_mutex);
+ up_write(&sb_dqopt(sb)->dqio_sem);
ocfs2_commit_trans(OCFS2_SB(sb), handle);
out_drop_lock:
ocfs2_unlock_global_qf(oinfo, 1);
@@ -693,7 +693,7 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
/* We don't need the lock and we have to acquire quota file locks
* which will later depend on this lock */
- mutex_unlock(&sb_dqopt(sb)->dqio_mutex);
+ up_write(&sb_dqopt(sb)->dqio_sem);
info->dqi_max_spc_limit = 0x7fffffffffffffffLL;
info->dqi_max_ino_limit = 0x7fffffffffffffffLL;
oinfo = kmalloc(sizeof(struct ocfs2_mem_dqinfo), GFP_NOFS);
@@ -772,7 +772,7 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
goto out_err;
}
- mutex_lock(&sb_dqopt(sb)->dqio_mutex);
+ down_write(&sb_dqopt(sb)->dqio_sem);
return 0;
out_err:
if (oinfo) {
@@ -786,7 +786,7 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
kfree(oinfo);
}
brelse(bh);
- mutex_lock(&sb_dqopt(sb)->dqio_mutex);
+ down_write(&sb_dqopt(sb)->dqio_sem);
return -1;
}
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 53a17496c5c5..29d447598642 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -120,7 +120,7 @@
* spinlock to internal buffers before writing.
*
* 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);
@@ -406,7 +406,7 @@ int dquot_acquire(struct dquot *dquot)
struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
mutex_lock(&dquot->dq_lock);
- mutex_lock(&dqopt->dqio_mutex);
+ down_write(&dqopt->dqio_sem);
if (!test_bit(DQ_READ_B, &dquot->dq_flags))
ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot);
if (ret < 0)
@@ -436,7 +436,7 @@ int dquot_acquire(struct dquot *dquot)
smp_mb__before_atomic();
set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
out_iolock:
- mutex_unlock(&dqopt->dqio_mutex);
+ up_write(&dqopt->dqio_sem);
mutex_unlock(&dquot->dq_lock);
return ret;
}
@@ -450,7 +450,7 @@ int dquot_commit(struct dquot *dquot)
int ret = 0;
struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
- mutex_lock(&dqopt->dqio_mutex);
+ down_write(&dqopt->dqio_sem);
spin_lock(&dq_list_lock);
if (!clear_dquot_dirty(dquot)) {
spin_unlock(&dq_list_lock);
@@ -464,7 +464,7 @@ int dquot_commit(struct dquot *dquot)
else
ret = -EIO;
out_sem:
- mutex_unlock(&dqopt->dqio_mutex);
+ up_write(&dqopt->dqio_sem);
return ret;
}
EXPORT_SYMBOL(dquot_commit);
@@ -481,7 +481,7 @@ int dquot_release(struct dquot *dquot)
/* 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);
+ down_write(&dqopt->dqio_sem);
if (dqopt->ops[dquot->dq_id.type]->release_dqblk) {
ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot);
/* Write the info */
@@ -493,7 +493,7 @@ int dquot_release(struct dquot *dquot)
ret = ret2;
}
clear_bit(DQ_ACTIVE_B, &dquot->dq_flags);
- mutex_unlock(&dqopt->dqio_mutex);
+ up_write(&dqopt->dqio_sem);
out_dqlock:
mutex_unlock(&dquot->dq_lock);
return ret;
@@ -2060,9 +2060,9 @@ int dquot_commit_info(struct super_block *sb, int type)
int ret;
struct quota_info *dqopt = sb_dqopt(sb);
- mutex_lock(&dqopt->dqio_mutex);
+ down_write(&dqopt->dqio_sem);
ret = dqopt->ops[type]->write_file_info(sb, type);
- mutex_unlock(&dqopt->dqio_mutex);
+ up_write(&dqopt->dqio_sem);
return ret;
}
EXPORT_SYMBOL(dquot_commit_info);
@@ -2076,9 +2076,9 @@ int dquot_get_next_id(struct super_block *sb, struct kqid *qid)
return -ESRCH;
if (!dqopt->ops[qid->type]->get_next_id)
return -ENOSYS;
- mutex_lock(&dqopt->dqio_mutex);
+ down_write(&dqopt->dqio_sem);
err = dqopt->ops[qid->type]->get_next_id(sb, qid);
- mutex_unlock(&dqopt->dqio_mutex);
+ up_write(&dqopt->dqio_sem);
return err;
}
EXPORT_SYMBOL(dquot_get_next_id);
@@ -2328,15 +2328,15 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_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);
+ down_write(&dqopt->dqio_sem);
error = dqopt->ops[type]->read_file_info(sb, type);
if (error < 0) {
- mutex_unlock(&dqopt->dqio_mutex);
+ up_write(&dqopt->dqio_sem);
goto out_file_init;
}
if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
dqopt->info[type].dqi_flags |= DQF_SYS_FILE;
- mutex_unlock(&dqopt->dqio_mutex);
+ up_write(&dqopt->dqio_sem);
spin_lock(&dq_state_lock);
dqopt->flags |= dquot_state_flag(flags, type);
spin_unlock(&dq_state_lock);
diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c
index 0738972e8d3f..54f85eb2609c 100644
--- a/fs/quota/quota_tree.c
+++ b/fs/quota/quota_tree.c
@@ -379,7 +379,7 @@ int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
if (!ddquot)
return -ENOMEM;
- /* dq_off is guarded by dqio_mutex */
+ /* dq_off is guarded by dqio_sem */
if (!dquot->dq_off) {
ret = dq_insert_tree(info, dquot);
if (ret < 0) {
diff --git a/fs/super.c b/fs/super.c
index 6bc3352adcf3..221cfa1f4e92 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -242,7 +242,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags,
atomic_set(&s->s_active, 1);
mutex_init(&s->s_vfs_rename_mutex);
lockdep_set_class(&s->s_vfs_rename_mutex, &type->s_vfs_rename_key);
- mutex_init(&s->s_dquot.dqio_mutex);
+ init_rwsem(&s->s_dquot.dqio_sem);
s->s_maxbytes = MAX_NON_LFS;
s->s_op = &default_op;
s->s_time_gran = 1000000000;
diff --git a/include/linux/quota.h b/include/linux/quota.h
index bfd077ca6ac3..3a6df7461642 100644
--- a/include/linux/quota.h
+++ b/include/linux/quota.h
@@ -521,7 +521,7 @@ static inline void quota_send_warning(struct kqid qid, dev_t dev,
struct quota_info {
unsigned int flags; /* Flags for diskquotas on this device */
- struct mutex dqio_mutex; /* lock device while I/O in progress */
+ struct rw_semaphore dqio_sem; /* Lock quota file while I/O in progress */
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 */
--
2.12.3
