From: Boris Burkov <boris@bur.io>
To: linux-btrfs@vger.kernel.org, kernel-team@fb.com
Subject: [PATCH 6/9] btrfs: auto hierarchy for simple qgroups of nested subvols
Date: Tue, 2 May 2023 17:59:27 -0700 [thread overview]
Message-ID: <b311f17d76094253b5b38be3ea845438628f17ad.1683075170.git.boris@bur.io> (raw)
In-Reply-To: <cover.1683075170.git.boris@bur.io>
Consider the following sequence:
- enable quotas
- create subvol S id 256 at dir outer/
- create a qgroup 1/100
- add 0/256 (S's auto qgroup) to 1/100
- create subvol T id 257 at dir outer/inner/
With full qgroups, there is no relationship between 0/257 and either of
0/256 or 1/100. There is an inherit feature that the creator of inner/
can use to specify it ought to be in 1/100.
Simple quotas are targeted at container isolation, where such automatic
inheritance for not necessarily trusted/controlled nested subvol
creation would be quite helpful. Therefore, add a new default behavior
for simple quotas: when you create a nested subvol, automatically
inherit as parents any parents of the qgroup of the subvol the new inode
is going in.
In our example, 257/0 would also be under 1/100, allowing easy control
of a total quota over an arbitrary hierarchy of subvolumes.
I think this _might_ be a generally useful behavior, so it could be
interesting to put it behind a new inheritance flag that simple quotas
always use while traditional quotas let the user specify, but this is a
minimally intrusive change to start.
Signed-off-by: Boris Burkov <boris@bur.io>
---
fs/btrfs/ioctl.c | 2 +-
fs/btrfs/qgroup.c | 46 +++++++++++++++++++++++++++++++++++++++---
fs/btrfs/qgroup.h | 6 +++---
fs/btrfs/transaction.c | 2 +-
4 files changed, 48 insertions(+), 8 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index ca7d2ef739c8..4d6d28feb5c6 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -652,7 +652,7 @@ static noinline int create_subvol(struct mnt_idmap *idmap,
/* Tree log can't currently deal with an inode which is a new root. */
btrfs_set_log_full_commit(trans);
- ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
+ ret = btrfs_qgroup_inherit(trans, 0, objectid, root->root_key.objectid, inherit);
if (ret)
goto out;
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index e3d0630fef0c..6816e01f00b5 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1504,8 +1504,7 @@ static int quick_update_accounting(struct btrfs_fs_info *fs_info,
return ret;
}
-int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
- u64 dst)
+int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, u64 dst)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_qgroup *parent;
@@ -2945,6 +2944,42 @@ int btrfs_run_qgroups(struct btrfs_trans_handle *trans)
return ret;
}
+static int qgroup_auto_inherit(struct btrfs_fs_info *fs_info,
+ u64 inode_rootid,
+ struct btrfs_qgroup_inherit **inherit)
+{
+ int i = 0;
+ u64 num_qgroups = 0;
+ struct btrfs_qgroup *inode_qg;
+ struct btrfs_qgroup_list *qg_list;
+
+ if (*inherit)
+ return -EEXIST;
+
+ inode_qg = find_qgroup_rb(fs_info, inode_rootid);
+ if (!inode_qg)
+ return -ENOENT;
+
+ list_for_each_entry(qg_list, &inode_qg->groups, next_group) {
+ ++num_qgroups;
+ }
+
+ if (!num_qgroups)
+ return 0;
+
+ *inherit = kzalloc(sizeof(**inherit) + num_qgroups * sizeof(u64), GFP_NOFS);
+ if (!*inherit)
+ return -ENOMEM;
+ (*inherit)->num_qgroups = num_qgroups;
+
+ list_for_each_entry(qg_list, &inode_qg->groups, next_group) {
+ u64 qg_id = qg_list->group->qgroupid;
+ *((u64 *)((*inherit)+1) + i) = qg_id;
+ }
+
+ return 0;
+}
+
/*
* Copy the accounting information between qgroups. This is necessary
* when a snapshot or a subvolume is created. Throwing an error will
@@ -2952,7 +2987,8 @@ int btrfs_run_qgroups(struct btrfs_trans_handle *trans)
* when a readonly fs is a reasonable outcome.
*/
int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
- u64 objectid, struct btrfs_qgroup_inherit *inherit)
+ u64 objectid, u64 inode_rootid,
+ struct btrfs_qgroup_inherit *inherit)
{
int ret = 0;
int i;
@@ -2994,6 +3030,9 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
goto out;
}
+ if (!inherit && btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE)
+ qgroup_auto_inherit(fs_info, inode_rootid, &inherit);
+
if (inherit) {
i_qgroups = (u64 *)(inherit + 1);
nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
@@ -3020,6 +3059,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
if (ret)
goto out;
+
/*
* add qgroup to all inherited groups
*/
diff --git a/fs/btrfs/qgroup.h b/fs/btrfs/qgroup.h
index b300998dcbc7..aecebe9d0d62 100644
--- a/fs/btrfs/qgroup.h
+++ b/fs/btrfs/qgroup.h
@@ -272,8 +272,7 @@ int btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info);
void btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info);
int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
bool interruptible);
-int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
- u64 dst);
+int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, u64 dst);
int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
u64 dst);
int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid);
@@ -367,7 +366,8 @@ int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans);
int btrfs_run_qgroups(struct btrfs_trans_handle *trans);
int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
- u64 objectid, struct btrfs_qgroup_inherit *inherit);
+ u64 objectid, u64 inode_rootid,
+ struct btrfs_qgroup_inherit *inherit);
void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
u64 ref_root, u64 num_bytes,
enum btrfs_qgroup_rsv_type type);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 0edfb58afd80..6befcf1b4b1f 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1557,7 +1557,7 @@ static int qgroup_account_snapshot(struct btrfs_trans_handle *trans,
/* Now qgroup are all updated, we can inherit it to new qgroups */
ret = btrfs_qgroup_inherit(trans, src->root_key.objectid, dst_objectid,
- inherit);
+ parent->root_key.objectid, inherit);
if (ret < 0)
goto out;
--
2.40.0
next prev parent reply other threads:[~2023-05-03 1:00 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-03 0:59 [PATCH RFC 0/9] btrfs: simple quotas Boris Burkov
2023-05-03 0:59 ` [PATCH 1/9] btrfs: simple quotas mode Boris Burkov
2023-05-03 2:38 ` Qu Wenruo
2023-05-03 0:59 ` [PATCH 2/9] btrfs: new function for recording simple quota usage Boris Burkov
2023-05-03 0:59 ` [PATCH 3/9] btrfs: track original extent subvol in a new inline ref Boris Burkov
2023-05-03 3:17 ` Qu Wenruo
2023-05-04 16:17 ` Boris Burkov
2023-05-04 21:49 ` Qu Wenruo
2023-05-09 23:58 ` David Sterba
2023-05-10 16:57 ` David Sterba
2023-05-11 0:07 ` Qu Wenruo
2023-05-13 6:31 ` Qu Wenruo
2023-05-03 0:59 ` [PATCH 4/9] btrfs: track metadata owning root in delayed refs Boris Burkov
2023-05-03 0:59 ` [PATCH 5/9] btrfs: record simple quota deltas Boris Burkov
2023-05-03 0:59 ` Boris Burkov [this message]
2023-05-03 4:47 ` [PATCH 6/9] btrfs: auto hierarchy for simple qgroups of nested subvols Qu Wenruo
2023-05-04 16:34 ` Boris Burkov
2023-05-04 21:55 ` Qu Wenruo
2023-05-03 0:59 ` [PATCH 7/9] btrfs: check generation when recording simple quota delta Boris Burkov
2023-05-03 0:59 ` [PATCH 8/9] btrfs: expose the qgroup mode via sysfs Boris Burkov
2023-05-03 0:59 ` [PATCH 9/9] btrfs: free qgroup rsv on io failure Boris Burkov
2023-05-05 4:13 ` [PATCH RFC 0/9] btrfs: simple quotas Anand Jain
2023-05-10 1:09 ` Boris Burkov
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