Linux-libre 4.6.2-gnu

4 files changed, 200 insertions, 7 deletions

diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 850d17fa0..ff21980d0 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -411,6 +411,8 @@ int dquot_acquire(struct dquot *dquot)
 		ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot);
 	if (ret < 0)
 		goto out_iolock;
+	/* Make sure flags update is visible after dquot has been filled */
+	smp_mb__before_atomic();
 	set_bit(DQ_READ_B, &dquot->dq_flags);
 	/* Instantiate dquot if needed */
 	if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) {
@@ -427,6 +429,11 @@ int dquot_acquire(struct dquot *dquot)
 			goto out_iolock;
 		}
 	}
+	/*
+	 * Make sure flags update is visible after on-disk struct has been
+	 * allocated. Paired with smp_rmb() in dqget().
+	 */
+	smp_mb__before_atomic();
 	set_bit(DQ_ACTIVE_B, &dquot->dq_flags);
 out_iolock:
 	mutex_unlock(&dqopt->dqio_mutex);
@@ -887,6 +894,11 @@ we_slept:
 			goto out;
 		}
 	}
+	/*
+	 * Make sure following reads see filled structure - paired with
+	 * smp_mb__before_atomic() in dquot_acquire().
+	 */
+	smp_rmb();
 #ifdef CONFIG_QUOTA_DEBUG
 	BUG_ON(!dquot->dq_sb);	/* Has somebody invalidated entry under us? */
 #endif
@@ -2030,6 +2042,30 @@ int dquot_commit_info(struct super_block *sb, int 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;
+
+	mutex_lock(&dqopt->dqonoff_mutex);
+	if (!sb_has_quota_active(sb, qid->type)) {
+		err = -ESRCH;
+		goto out;
+	}
+	if (!dqopt->ops[qid->type]->get_next_id) {
+		err = -ENOSYS;
+		goto out;
+	}
+	mutex_lock(&dqopt->dqio_mutex);
+	err = dqopt->ops[qid->type]->get_next_id(sb, qid);
+	mutex_unlock(&dqopt->dqio_mutex);
+out:
+	mutex_unlock(&dqopt->dqonoff_mutex);
+
+	return err;
+}
+EXPORT_SYMBOL(dquot_get_next_id);
+
 /*
  * Definitions of diskquota operations.
  */
@@ -2041,6 +2077,7 @@ const struct dquot_operations dquot_operations = {
 	.write_info	= dquot_commit_info,
 	.alloc_dquot	= dquot_alloc,
 	.destroy_dquot	= dquot_destroy,
+	.get_next_id	= dquot_get_next_id,
 };
 EXPORT_SYMBOL(dquot_operations);
 
@@ -2429,9 +2466,7 @@ int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
 	struct dentry *dentry;
 	int error;
 
-	inode_lock(d_inode(sb->s_root));
-	dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name));
-	inode_unlock(d_inode(sb->s_root));
+	dentry = lookup_one_len_unlocked(qf_name, sb->s_root, strlen(qf_name));
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
 
@@ -2564,6 +2599,27 @@ int dquot_get_dqblk(struct super_block *sb, struct kqid qid,
 }
 EXPORT_SYMBOL(dquot_get_dqblk);
 
+int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid,
+			 struct qc_dqblk *di)
+{
+	struct dquot *dquot;
+	int err;
+
+	if (!sb->dq_op->get_next_id)
+		return -ENOSYS;
+	err = sb->dq_op->get_next_id(sb, qid);
+	if (err < 0)
+		return err;
+	dquot = dqget(sb, *qid);
+	if (IS_ERR(dquot))
+		return PTR_ERR(dquot);
+	do_get_dqblk(dquot, di);
+	dqput(dquot);
+
+	return 0;
+}
+EXPORT_SYMBOL(dquot_get_next_dqblk);
+
 #define VFS_QC_MASK \
 	(QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \
 	 QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \
@@ -2764,6 +2820,7 @@ const struct quotactl_ops dquot_quotactl_ops = {
 	.get_state	= dquot_get_state,
 	.set_info	= dquot_set_dqinfo,
 	.get_dqblk	= dquot_get_dqblk,
+	.get_nextdqblk	= dquot_get_next_dqblk,
 	.set_dqblk	= dquot_set_dqblk
 };
 EXPORT_SYMBOL(dquot_quotactl_ops);
@@ -2775,6 +2832,7 @@ const struct quotactl_ops dquot_quotactl_sysfile_ops = {
 	.get_state	= dquot_get_state,
 	.set_info	= dquot_set_dqinfo,
 	.get_dqblk	= dquot_get_dqblk,
+	.get_nextdqblk	= dquot_get_next_dqblk,
 	.set_dqblk	= dquot_set_dqblk
 };
 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops);
diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 374636709..0f10ee989 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -79,7 +79,7 @@ unsigned int qtype_enforce_flag(int type)
 	return 0;
 }
 
-static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
+static int quota_quotaon(struct super_block *sb, int type, qid_t id,
 		         struct path *path)
 {
 	if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_enable)
@@ -222,6 +222,34 @@ static int quota_getquota(struct super_block *sb, int type, qid_t id,
 	return 0;
 }
 
+/*
+ * Return quota for next active quota >= this id, if any exists,
+ * otherwise return -ENOENT via ->get_nextdqblk
+ */
+static int quota_getnextquota(struct super_block *sb, int type, qid_t id,
+			  void __user *addr)
+{
+	struct kqid qid;
+	struct qc_dqblk fdq;
+	struct if_nextdqblk idq;
+	int ret;
+
+	if (!sb->s_qcop->get_nextdqblk)
+		return -ENOSYS;
+	qid = make_kqid(current_user_ns(), type, id);
+	if (!qid_valid(qid))
+		return -EINVAL;
+	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &fdq);
+	if (ret)
+		return ret;
+	/* struct if_nextdqblk is a superset of struct if_dqblk */
+	copy_to_if_dqblk((struct if_dqblk *)&idq, &fdq);
+	idq.dqb_id = from_kqid(current_user_ns(), qid);
+	if (copy_to_user(addr, &idq, sizeof(idq)))
+		return -EFAULT;
+	return 0;
+}
+
 static void copy_from_if_dqblk(struct qc_dqblk *dst, struct if_dqblk *src)
 {
 	dst->d_spc_hardlimit = qbtos(src->dqb_bhardlimit);
@@ -625,6 +653,34 @@ static int quota_getxquota(struct super_block *sb, int type, qid_t id,
 	return ret;
 }
 
+/*
+ * Return quota for next active quota >= this id, if any exists,
+ * otherwise return -ENOENT via ->get_nextdqblk.
+ */
+static int quota_getnextxquota(struct super_block *sb, int type, qid_t id,
+			    void __user *addr)
+{
+	struct fs_disk_quota fdq;
+	struct qc_dqblk qdq;
+	struct kqid qid;
+	qid_t id_out;
+	int ret;
+
+	if (!sb->s_qcop->get_nextdqblk)
+		return -ENOSYS;
+	qid = make_kqid(current_user_ns(), type, id);
+	if (!qid_valid(qid))
+		return -EINVAL;
+	ret = sb->s_qcop->get_nextdqblk(sb, &qid, &qdq);
+	if (ret)
+		return ret;
+	id_out = from_kqid(current_user_ns(), qid);
+	copy_to_xfs_dqblk(&fdq, &qdq, type, id_out);
+	if (copy_to_user(addr, &fdq, sizeof(fdq)))
+		return -EFAULT;
+	return ret;
+}
+
 static int quota_rmxquota(struct super_block *sb, void __user *addr)
 {
 	__u32 flags;
@@ -659,7 +715,7 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 
 	switch (cmd) {
 	case Q_QUOTAON:
-		return quota_quotaon(sb, type, cmd, id, path);
+		return quota_quotaon(sb, type, id, path);
 	case Q_QUOTAOFF:
 		return quota_quotaoff(sb, type);
 	case Q_GETFMT:
@@ -670,6 +726,8 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 		return quota_setinfo(sb, type, addr);
 	case Q_GETQUOTA:
 		return quota_getquota(sb, type, id, addr);
+	case Q_GETNEXTQUOTA:
+		return quota_getnextquota(sb, type, id, addr);
 	case Q_SETQUOTA:
 		return quota_setquota(sb, type, id, addr);
 	case Q_SYNC:
@@ -690,6 +748,8 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 		return quota_setxquota(sb, type, id, addr);
 	case Q_XGETQUOTA:
 		return quota_getxquota(sb, type, id, addr);
+	case Q_XGETNEXTQUOTA:
+		return quota_getnextxquota(sb, type, id, addr);
 	case Q_XQUOTASYNC:
 		if (sb->s_flags & MS_RDONLY)
 			return -EROFS;
@@ -705,6 +765,11 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
 /* Return 1 if 'cmd' will block on frozen filesystem */
 static int quotactl_cmd_write(int cmd)
 {
+	/*
+	 * We cannot allow Q_GETQUOTA and Q_GETNEXTQUOTA without write access
+	 * as dquot_acquire() may allocate space for new structure and OCFS2
+	 * needs to increment on-disk use count.
+	 */
 	switch (cmd) {
 	case Q_GETFMT:
 	case Q_GETINFO:
@@ -712,6 +777,7 @@ static int quotactl_cmd_write(int cmd)
 	case Q_XGETQSTAT:
 	case Q_XGETQSTATV:
 	case Q_XGETQUOTA:
+	case Q_XGETNEXTQUOTA:
 	case Q_XQUOTASYNC:
 		return 0;
 	}
diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c
index 58efb83de..0738972e8 100644
--- a/fs/quota/quota_tree.c
+++ b/fs/quota/quota_tree.c
@@ -22,10 +22,9 @@ MODULE_LICENSE("GPL");
 
 #define __QUOTA_QT_PARANOIA
 
-static int get_index(struct qtree_mem_dqinfo *info, struct kqid qid, int depth)
+static int __get_index(struct qtree_mem_dqinfo *info, qid_t id, int depth)
 {
 	unsigned int epb = info->dqi_usable_bs >> 2;
-	qid_t id = from_kqid(&init_user_ns, qid);
 
 	depth = info->dqi_qtree_depth - depth - 1;
 	while (depth--)
@@ -33,6 +32,13 @@ static int get_index(struct qtree_mem_dqinfo *info, struct kqid qid, int depth)
 	return id % epb;
 }
 
+static int get_index(struct qtree_mem_dqinfo *info, struct kqid qid, int depth)
+{
+	qid_t id = from_kqid(&init_user_ns, qid);
+
+	return __get_index(info, id, depth);
+}
+
 /* Number of entries in one blocks */
 static int qtree_dqstr_in_blk(struct qtree_mem_dqinfo *info)
 {
@@ -668,3 +674,60 @@ int qtree_release_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
 	return 0;
 }
 EXPORT_SYMBOL(qtree_release_dquot);
+
+static int find_next_id(struct qtree_mem_dqinfo *info, qid_t *id,
+			unsigned int blk, int depth)
+{
+	char *buf = getdqbuf(info->dqi_usable_bs);
+	__le32 *ref = (__le32 *)buf;
+	ssize_t ret;
+	unsigned int epb = info->dqi_usable_bs >> 2;
+	unsigned int level_inc = 1;
+	int i;
+
+	if (!buf)
+		return -ENOMEM;
+
+	for (i = depth; i < info->dqi_qtree_depth - 1; i++)
+		level_inc *= epb;
+
+	ret = read_blk(info, blk, buf);
+	if (ret < 0) {
+		quota_error(info->dqi_sb,
+			    "Can't read quota tree block %u", blk);
+		goto out_buf;
+	}
+	for (i = __get_index(info, *id, depth); i < epb; i++) {
+		if (ref[i] == cpu_to_le32(0)) {
+			*id += level_inc;
+			continue;
+		}
+		if (depth == info->dqi_qtree_depth - 1) {
+			ret = 0;
+			goto out_buf;
+		}
+		ret = find_next_id(info, id, le32_to_cpu(ref[i]), depth + 1);
+		if (ret != -ENOENT)
+			break;
+	}
+	if (i == epb) {
+		ret = -ENOENT;
+		goto out_buf;
+	}
+out_buf:
+	kfree(buf);
+	return ret;
+}
+
+int qtree_get_next_id(struct qtree_mem_dqinfo *info, struct kqid *qid)
+{
+	qid_t id = from_kqid(&init_user_ns, *qid);
+	int ret;
+
+	ret = find_next_id(info, &id, QT_TREEOFF, 0);
+	if (ret < 0)
+		return ret;
+	*qid = make_kqid(&init_user_ns, qid->type, id);
+	return 0;
+}
+EXPORT_SYMBOL(qtree_get_next_id);
diff --git a/fs/quota/quota_v2.c b/fs/quota/quota_v2.c
index ed85d4f35..ca71bf881 100644
--- a/fs/quota/quota_v2.c
+++ b/fs/quota/quota_v2.c
@@ -304,6 +304,11 @@ static int v2_free_file_info(struct super_block *sb, int type)
 	return 0;
 }
 
+static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
+{
+	return qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
+}
+
 static const struct quota_format_ops v2_format_ops = {
 	.check_quota_file	= v2_check_quota_file,
 	.read_file_info		= v2_read_file_info,
@@ -312,6 +317,7 @@ static const struct quota_format_ops v2_format_ops = {
 	.read_dqblk		= v2_read_dquot,
 	.commit_dqblk		= v2_write_dquot,
 	.release_dqblk		= v2_release_dquot,
+	.get_next_id		= v2_get_next_id,
 };
 
 static struct quota_format_type v2r0_quota_format = {