diff options
author | Qu Wenruo <wqu@suse.com> | 2021-08-13 17:55:26 +0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-08-15 13:08:05 +0200 |
commit | 5c79287c2b6d3be01c5ba0b1306e8529137ae28d (patch) | |
tree | 3f51595eb1e55b800494a0edf6cc7fb8666680cd /fs/btrfs/disk-io.c | |
parent | b7a722fd75a1701011056b76da5020ec4b295a4e (diff) |
btrfs: qgroup: allow to unreserve range without releasing other ranges
commit 263da812e87bac4098a4778efaa32c54275641db upstream
[PROBLEM]
Before this patch, when btrfs_qgroup_reserve_data() fails, we free all
reserved space of the changeset.
For example:
ret = btrfs_qgroup_reserve_data(inode, changeset, 0, SZ_1M);
ret = btrfs_qgroup_reserve_data(inode, changeset, SZ_1M, SZ_1M);
ret = btrfs_qgroup_reserve_data(inode, changeset, SZ_2M, SZ_1M);
If the last btrfs_qgroup_reserve_data() failed, it will release the
entire [0, 3M) range.
This behavior is kind of OK for now, as when we hit -EDQUOT, we normally
go error handling and need to release all reserved ranges anyway.
But this also means the following call is not possible:
ret = btrfs_qgroup_reserve_data();
if (ret == -EDQUOT) {
/* Do something to free some qgroup space */
ret = btrfs_qgroup_reserve_data();
}
As if the first btrfs_qgroup_reserve_data() fails, it will free all
reserved qgroup space.
[CAUSE]
This is because we release all reserved ranges when
btrfs_qgroup_reserve_data() fails.
[FIX]
This patch will implement a new function, qgroup_unreserve_range(), to
iterate through the ulist nodes, to find any nodes in the failure range,
and remove the EXTENT_QGROUP_RESERVED bits from the io_tree, and
decrease the extent_changeset::bytes_changed, so that we can revert to
previous state.
This allows later patches to retry btrfs_qgroup_reserve_data() if EDQUOT
happens.
Suggested-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/btrfs/disk-io.c')
0 files changed, 0 insertions, 0 deletions