quota: Push dqio_sem down to ->read_file_info()

Push down acquisition of dqio_sem into ->read_file_info() callback. This
is for consistency with other operations and it also allows us to get
rid of an ugliness in OCFS2.

Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Jan Kara <jack@suse.cz>

fs/ocfs2/quota_local.c

@@ -691,9 +691,6 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
 	struct ocfs2_quota_recovery *rec;
 	int locked = 0;
 
-	/* We don't need the lock and we have to acquire quota file locks
-	 * which will later depend on this lock */
-	up_read(&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 +769,6 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
 		goto out_err;
 	}
 
-	down_read(&sb_dqopt(sb)->dqio_sem);
 	return 0;
 out_err:
 	if (oinfo) {
@@ -786,7 +782,6 @@ out_err:
 		kfree(oinfo);
 	}
 	brelse(bh);
-	down_read(&sb_dqopt(sb)->dqio_sem);
 	return -1;
 }
 

fs/quota/dquot.c

@@ -2313,15 +2313,11 @@ 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);
-	down_read(&dqopt->dqio_sem);
 	error = dqopt->ops[type]->read_file_info(sb, type);
-	if (error < 0) {
-		up_read(&dqopt->dqio_sem);
+	if (error < 0)
 		goto out_file_init;
-	}
 	if (dqopt->flags & DQUOT_QUOTA_SYS_FILE)
 		dqopt->info[type].dqi_flags |= DQF_SYS_FILE;
-	up_read(&dqopt->dqio_sem);
 	spin_lock(&dq_state_lock);
 	dqopt->flags |= dquot_state_flag(flags, type);
 	spin_unlock(&dq_state_lock);

fs/quota/quota_v1.c

@@ -161,6 +161,7 @@ static int v1_read_file_info(struct super_block *sb, int type)
 	struct v1_disk_dqblk dqblk;
 	int ret;
 
+	down_read(&dqopt->dqio_sem);
 	ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
 				sizeof(struct v1_disk_dqblk), v1_dqoff(0));
 	if (ret != sizeof(struct v1_disk_dqblk)) {
@@ -177,6 +178,7 @@ static int v1_read_file_info(struct super_block *sb, int type)
 	dqopt->info[type].dqi_bgrace =
 			dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
 out:
+	up_read(&dqopt->dqio_sem);
 	return ret;
 }
 

fs/quota/quota_v2.c

@@ -90,29 +90,38 @@ static int v2_read_file_info(struct super_block *sb, int type)
 {
 	struct v2_disk_dqinfo dinfo;
 	struct v2_disk_dqheader dqhead;
-	struct mem_dqinfo *info = sb_dqinfo(sb, type);
+	struct quota_info *dqopt = sb_dqopt(sb);
+	struct mem_dqinfo *info = &dqopt->info[type];
 	struct qtree_mem_dqinfo *qinfo;
 	ssize_t size;
 	unsigned int version;
+	int ret;
 
-	if (!v2_read_header(sb, type, &dqhead))
-		return -1;
+	down_read(&dqopt->dqio_sem);
+	if (!v2_read_header(sb, type, &dqhead)) {
+		ret = -1;
+		goto out;
+	}
 	version = le32_to_cpu(dqhead.dqh_version);
 	if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) ||
-	    (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1))
-		return -1;
+	    (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1)) {
+		ret = -1;
+		goto out;
+	}
 
 	size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
 	       sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 	if (size != sizeof(struct v2_disk_dqinfo)) {
 		quota_error(sb, "Can't read info structure");
-		return -1;
+		ret = -1;
+		goto out;
 	}
 	info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
 	if (!info->dqi_priv) {
 		printk(KERN_WARNING
 		       "Not enough memory for quota information structure.\n");
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out;
 	}
 	qinfo = info->dqi_priv;
 	if (version == 0) {
@@ -147,7 +156,10 @@ static int v2_read_file_info(struct super_block *sb, int type)
 		qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
 		qinfo->dqi_ops = &v2r1_qtree_ops;
 	}
-	return 0;
+	ret = 0;
+out:
+	up_read(&dqopt->dqio_sem);
+	return ret;
 }
 
 /* Write information header to quota file */