Commit c3b00446 authored by Jan Kara's avatar Jan Kara
Browse files

quota: Remove dqonoff_mutex 



The only places that were grabbing dqonoff_mutex are functions turning
quotas on and off and these are properly serialized using s_umount
semaphore. Remove dqonoff_mutex.

Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 5f530de6

fs/quota/dquot.c

+23 −57
Original line number Diff line number Diff line
@@ -119,8 +119,7 @@ 
 * spinlock to internal buffers before writing.

 *

 * Lock ordering (including related VFS locks) is the following:

 *   dqonoff_mutex > i_mutex > journal_lock > dquot->dq_lock > dqio_mutex

 * dqonoff_mutex > i_mutex comes from dquot_quota_sync, dquot_enable, etc.

 *   s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_mutex

 */



static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock);
@@ -933,7 +932,7 @@ static int dqinit_needed(struct inode *inode, int type) 
	return 0;

}



/* This routine is guarded by dqonoff_mutex mutex */

/* This routine is guarded by s_umount semaphore */

static void add_dquot_ref(struct super_block *sb, int type)

{

	struct inode *inode, *old_inode = NULL;
@@ -2108,18 +2107,14 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags) 
	    DQUOT_USAGE_ENABLED)))

		return -EINVAL;



	/* We need to serialize quota_off() for device */

	mutex_lock(&dqopt->dqonoff_mutex);



	/*

	 * Skip everything if there's nothing to do. We have to do this because

	 * sometimes we are called when fill_super() failed and calling

	 * sync_fs() in such cases does no good.

	 */

	if (!sb_any_quota_loaded(sb)) {

		mutex_unlock(&dqopt->dqonoff_mutex);

	if (!sb_any_quota_loaded(sb))

		return 0;

	}



	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {

		toputinode[cnt] = NULL;

		if (type != -1 && cnt != type)
@@ -2173,7 +2168,6 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags) 
		dqopt->info[cnt].dqi_bgrace = 0;

		dqopt->ops[cnt] = NULL;

	}

	mutex_unlock(&dqopt->dqonoff_mutex);



	/* Skip syncing and setting flags if quota files are hidden */

	if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
@@ -2191,20 +2185,14 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags) 
	 * changes done by userspace on the next quotaon() */

	for (cnt = 0; cnt < MAXQUOTAS; cnt++)

		if (toputinode[cnt]) {

			mutex_lock(&dqopt->dqonoff_mutex);

			/* If quota was reenabled in the meantime, we have

			 * nothing to do */

			if (!sb_has_quota_loaded(sb, cnt)) {

			WARN_ON_ONCE(sb_has_quota_loaded(sb, cnt));

			inode_lock(toputinode[cnt]);

			toputinode[cnt]->i_flags &= ~(S_IMMUTABLE |

				  S_NOATIME | S_NOQUOTA);

				truncate_inode_pages(&toputinode[cnt]->i_data,

						     0);

			truncate_inode_pages(&toputinode[cnt]->i_data, 0);

			inode_unlock(toputinode[cnt]);

			mark_inode_dirty_sync(toputinode[cnt]);

		}

			mutex_unlock(&dqopt->dqonoff_mutex);

		}

	if (sb->s_bdev)

		invalidate_bdev(sb->s_bdev);

put_inodes:
@@ -2275,6 +2263,10 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 
		error = -EINVAL;

		goto out_fmt;

	}

	if (sb_has_quota_loaded(sb, type)) {

		error = -EBUSY;

		goto out_fmt;

	}



	if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {

		/* As we bypass the pagecache we must now flush all the
@@ -2286,11 +2278,6 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 
		sync_filesystem(sb);

		invalidate_bdev(sb->s_bdev);

	}

	mutex_lock(&dqopt->dqonoff_mutex);

	if (sb_has_quota_loaded(sb, type)) {

		error = -EBUSY;

		goto out_lock;

	}



	if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) {

		/* We don't want quota and atime on quota files (deadlocks
@@ -2311,7 +2298,7 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 
	error = -EIO;

	dqopt->files[type] = igrab(inode);

	if (!dqopt->files[type])

		goto out_lock;

		goto out_file_flags;

	error = -EINVAL;

	if (!fmt->qf_ops->check_quota_file(sb, type))

		goto out_file_init;
@@ -2334,14 +2321,13 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 
	spin_unlock(&dq_state_lock);



	add_dquot_ref(sb, type);

	mutex_unlock(&dqopt->dqonoff_mutex);



	return 0;



out_file_init:

	dqopt->files[type] = NULL;

	iput(inode);

out_lock:

out_file_flags:

	if (oldflags != -1) {

		inode_lock(inode);

		/* Set the flags back (in the case of accidental quotaon()
@@ -2350,7 +2336,6 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 
		inode->i_flags |= oldflags;

		inode_unlock(inode);

	}

	mutex_unlock(&dqopt->dqonoff_mutex);

out_fmt:

	put_quota_format(fmt);
@@ -2372,12 +2357,9 @@ int dquot_resume(struct super_block *sb, int type) 
	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {

		if (type != -1 && cnt != type)

			continue;



		mutex_lock(&dqopt->dqonoff_mutex);

		if (!sb_has_quota_suspended(sb, cnt)) {

			mutex_unlock(&dqopt->dqonoff_mutex);

		if (!sb_has_quota_suspended(sb, cnt))

			continue;

		}



		inode = dqopt->files[cnt];

		dqopt->files[cnt] = NULL;

		spin_lock(&dq_state_lock);
@@ -2386,7 +2368,6 @@ int dquot_resume(struct super_block *sb, int type) 
							cnt);

		dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt);

		spin_unlock(&dq_state_lock);

		mutex_unlock(&dqopt->dqonoff_mutex);



		flags = dquot_generic_flag(flags, cnt);

		ret = vfs_load_quota_inode(inode, cnt,
@@ -2422,9 +2403,7 @@ EXPORT_SYMBOL(dquot_quota_on); 
int dquot_enable(struct inode *inode, int type, int format_id,

		 unsigned int flags)

{

	int ret = 0;

	struct super_block *sb = inode->i_sb;

	struct quota_info *dqopt = sb_dqopt(sb);



	/* Just unsuspend quotas? */

	BUG_ON(flags & DQUOT_SUSPENDED);
@@ -2436,31 +2415,18 @@ int dquot_enable(struct inode *inode, int type, int format_id, 
		return 0;

	/* Just updating flags needed? */

	if (sb_has_quota_loaded(sb, type)) {

		mutex_lock(&dqopt->dqonoff_mutex);

		/* Now do a reliable test... */

		if (!sb_has_quota_loaded(sb, type)) {

			mutex_unlock(&dqopt->dqonoff_mutex);

			goto load_quota;

		}

		if (flags & DQUOT_USAGE_ENABLED &&

		    sb_has_quota_usage_enabled(sb, type)) {

			ret = -EBUSY;

			goto out_lock;

		}

		    sb_has_quota_usage_enabled(sb, type))

			return -EBUSY;

		if (flags & DQUOT_LIMITS_ENABLED &&

		    sb_has_quota_limits_enabled(sb, type)) {

			ret = -EBUSY;

			goto out_lock;

		}

		    sb_has_quota_limits_enabled(sb, type))

			return -EBUSY;

		spin_lock(&dq_state_lock);

		sb_dqopt(sb)->flags |= dquot_state_flag(flags, type);

		spin_unlock(&dq_state_lock);

out_lock:

		mutex_unlock(&dqopt->dqonoff_mutex);

		return ret;

		return 0;

	}



load_quota:

	return vfs_load_quota_inode(inode, type, format_id, flags);

}

EXPORT_SYMBOL(dquot_enable);

fs/super.c

+0 −1
Original line number Diff line number Diff line
@@ -244,7 +244,6 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags, 
	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);

	mutex_init(&s->s_dquot.dqonoff_mutex);

	s->s_maxbytes = MAX_NON_LFS;

	s->s_op = &default_op;

	s->s_time_gran = 1000000000;

include/linux/quota.h

+0 −1
Original line number Diff line number Diff line
@@ -520,7 +520,6 @@ 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 mutex dqonoff_mutex;		/* Serialize quotaon & quotaoff */

	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 */