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Commit bc8230ee authored by Jan Kara's avatar Jan Kara
Browse files

quota: Convert dqio_mutex to rwsem 



Convert dqio_mutex to rwsem and call it dqio_sem. No functional changes
yet.

Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent aae4e7a8

fs/ext4/super.c

+4 −9
Original line number Diff line number Diff line
@@ -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];

fs/ocfs2/quota_global.c

+10 −10
Original line number Diff line number Diff line
@@ -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);

fs/ocfs2/quota_local.c

+5 −5
Original line number Diff line number Diff line
@@ -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;

}

fs/quota/dquot.c

+14 −14
Original line number Diff line number Diff line
@@ -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);

fs/quota/quota_tree.c

+1 −1
Original line number Diff line number Diff line
@@ -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) {