From c5860505a9b00e03d26d9e5a42884500402ac267 Mon Sep 17 00:00:00 2001
From: Qu Wenruo <quwenruo@cn.fujitsu.com>
Date: Mon, 12 Oct 2015 16:05:40 +0800
Subject: [PATCH] btrfs: qgroup: Introduce btrfs_qgroup_reserve_data function
Introduce a new function, btrfs_qgroup_reserve_data(), which will use
io_tree to accurate qgroup reserve, to avoid reserved space leaking.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
---
fs/btrfs/extent_io.h | 1 +
fs/btrfs/qgroup.c | 49 ++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/qgroup.h | 2 ++
3 files changed, 52 insertions(+)
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 51e1b71432564..f4c1ae11855f0 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -19,6 +19,7 @@
#define EXTENT_NEED_WAIT (1U << 13)
#define EXTENT_DAMAGED (1U << 14)
#define EXTENT_NORESERVE (1U << 15)
+#define EXTENT_QGROUP_RESERVED (1U << 16)
#define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
#define EXTENT_CTLBITS (EXTENT_DO_ACCOUNTING | EXTENT_FIRST_DELALLOC)
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index d904ee1c53497..50662748532a3 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2486,3 +2486,52 @@ btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
btrfs_queue_work(fs_info->qgroup_rescan_workers,
&fs_info->qgroup_rescan_work);
}
+
+/*
+ * Reserve qgroup space for range [start, start + len).
+ *
+ * This function will either reserve space from related qgroups or doing
+ * nothing if the range is already reserved.
+ *
+ * Return 0 for successful reserve
+ * Return <0 for error (including -EQUOT)
+ *
+ * NOTE: this function may sleep for memory allocation.
+ */
+int btrfs_qgroup_reserve_data(struct inode *inode, u64 start, u64 len)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_changeset changeset;
+ struct ulist_node *unode;
+ struct ulist_iterator uiter;
+ int ret;
+
+ if (!root->fs_info->quota_enabled || !is_fstree(root->objectid) ||
+ len == 0)
+ return 0;
+
+ changeset.bytes_changed = 0;
+ changeset.range_changed = ulist_alloc(GFP_NOFS);
+
+ ret = set_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
+ start + len -1, EXTENT_QGROUP_RESERVED, GFP_NOFS,
+ &changeset);
+ if (ret < 0)
+ goto cleanup;
+ ret = btrfs_qgroup_reserve(root, changeset.bytes_changed);
+ if (ret < 0)
+ goto cleanup;
+
+ ulist_free(changeset.range_changed);
+ return ret;
+
+cleanup:
+ /* cleanup already reserved ranges */
+ ULIST_ITER_INIT(&uiter);
+ while ((unode = ulist_next(changeset.range_changed, &uiter)))
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, unode->val,
+ unode->aux, EXTENT_QGROUP_RESERVED, 0, 0, NULL,
+ GFP_NOFS);
+ ulist_free(changeset.range_changed);
+ return ret;
+}
diff --git a/fs/btrfs/qgroup.h b/fs/btrfs/qgroup.h
index 6387dcfa354c6..bd17cc24335cf 100644
--- a/fs/btrfs/qgroup.h
+++ b/fs/btrfs/qgroup.h
@@ -81,4 +81,6 @@ int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
u64 rfer, u64 excl);
#endif
+/* New io_tree based accurate qgroup reserve API */
+int btrfs_qgroup_reserve_data(struct inode *inode, u64 start, u64 len);
#endif /* __BTRFS_QGROUP__ */
--
2.39.5