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>
This commit is contained in:
Qu Wenruo 2015-10-12 16:05:40 +08:00 committed by Chris Mason
parent fefdc55702
commit 5247255370
3 changed files with 52 additions and 0 deletions

View file

@ -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)

View file

@ -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;
}

View file

@ -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__ */