From f59c0347d4be22dad5812b5b14bf94ac0efd371a Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@suse.com>
Date: Tue, 12 Dec 2017 15:34:24 +0800
Patch-mainline: v4.17-rc1
Git-commit: f59c0347d4be22dad5812b5b14bf94ac0efd371a
References: bsc#1031392
Subject: [PATCH 08/16] btrfs: qgroup: Introduce helpers to update and access
new qgroup rsv
Introduce helpers to:
1) Get total reserved space
For limit calculation
2) Add/release reserved space for given type
With underflow detection and warning
3) Add/release reserved space according to child qgroup
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
fs/btrfs/qgroup.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 68 insertions(+)
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index d6ab07f40f82..252af87340cc 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -47,6 +47,74 @@
* - check all ioctl parameters
*/
+/*
+ * Helpers to access qgroup reservation
+ *
+ * Callers should ensure the lock context and type are valid
+ */
+
+static u64 qgroup_rsv_total(const struct btrfs_qgroup *qgroup)
+{
+ u64 ret = 0;
+ int i;
+
+ for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
+ ret += qgroup->rsv.values[i];
+
+ return ret;
+}
+
+#ifdef CONFIG_BTRFS_DEBUG
+static const char *qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type)
+{
+ if (type == BTRFS_QGROUP_RSV_DATA)
+ return "data";
+ if (type == BTRFS_QGROUP_RSV_META)
+ return "meta";
+ return NULL;
+}
+#endif
+
+static void qgroup_rsv_add(struct btrfs_qgroup *qgroup, u64 num_bytes,
+ enum btrfs_qgroup_rsv_type type)
+{
+ qgroup->rsv.values[type] += num_bytes;
+}
+
+static void qgroup_rsv_release(struct btrfs_qgroup *qgroup, u64 num_bytes,
+ enum btrfs_qgroup_rsv_type type)
+{
+ if (qgroup->rsv.values[type] >= num_bytes) {
+ qgroup->rsv.values[type] -= num_bytes;
+ return;
+ }
+#ifdef CONFIG_BTRFS_DEBUG
+ WARN_RATELIMIT(1,
+ "qgroup %llu %s reserved space underflow, have %llu to free %llu",
+ qgroup->qgroupid, qgroup_rsv_type_str(type),
+ qgroup->rsv.values[type], num_bytes);
+#endif
+ qgroup->rsv.values[type] = 0;
+}
+
+static void qgroup_rsv_add_by_qgroup(struct btrfs_qgroup *dest,
+ struct btrfs_qgroup *src)
+{
+ int i;
+
+ for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
+ qgroup_rsv_add(dest, src->rsv.values[i], i);
+}
+
+static void qgroup_rsv_release_by_qgroup(struct btrfs_qgroup *dest,
+ struct btrfs_qgroup *src)
+{
+ int i;
+
+ for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
+ qgroup_rsv_release(dest, src->rsv.values[i], i);
+}
+
static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
int mod)
{
--
2.19.0