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btrfs: qgroup: prealloc btrfs_qgroup_list for __add_relation_rb()

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Currently we go GFP_ATOMIC allocation for qgroup relation add, this
includes the following 3 call sites:

- btrfs_read_qgroup_config()
  This is not really needed, as at that time we're still in single
  thread mode, and no spin lock is held.

- btrfs_add_qgroup_relation()
  This one is holding a spinlock, but we're ensured to add at most one
  relation, thus we can easily do a preallocation and use the
  preallocated memory to avoid GFP_ATOMIC.

- btrfs_qgroup_inherit()
  This is a little more tricky, as we may have as many relationships as
  inherit::num_qgroups.
  Thus we have to properly allocate an array then preallocate all the
  memory.

This patch would remove the GFP_ATOMIC allocation for above involved
call sites, by doing preallocation before holding the spinlock, and let
__add_relation_rb() to handle the freeing of the structure.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2023-09-01 10:11:16 +08:00 committed by David Sterba
parent 8d54518b5e
commit 79ace7b807
1 changed files with 59 additions and 19 deletions
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78
fs/btrfs/qgroup.c
View File

@ -266,27 +266,26 @@ static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
/*
* Add relation specified by two qgroups.
*
* Must be called with qgroup_lock held.
* Must be called with qgroup_lock held, the ownership of @prealloc is
* transferred to this function and caller should not touch it anymore.
*
* Return: 0 on success
* -ENOENT if one of the qgroups is NULL
* <0 other errors
*/
static int __add_relation_rb(struct btrfs_qgroup *member, struct btrfs_qgroup *parent)
static int __add_relation_rb(struct btrfs_qgroup_list *prealloc,
struct btrfs_qgroup *member,
struct btrfs_qgroup *parent)
{
struct btrfs_qgroup_list *list;
if (!member || !parent)
if (!member || !parent) {
kfree(prealloc);
return -ENOENT;
}
list = kzalloc(sizeof(*list), GFP_ATOMIC);
if (!list)
return -ENOMEM;
list->group = parent;
list->member = member;
list_add_tail(&list->next_group, &member->groups);
list_add_tail(&list->next_member, &parent->members);
prealloc->group = parent;
prealloc->member = member;
list_add_tail(&prealloc->next_group, &member->groups);
list_add_tail(&prealloc->next_member, &parent->members);
return 0;
}
@ -300,7 +299,9 @@ static int __add_relation_rb(struct btrfs_qgroup *member, struct btrfs_qgroup *p
* -ENOENT if one of the ids does not exist
* <0 other errors
*/
static int add_relation_rb(struct btrfs_fs_info *fs_info, u64 memberid, u64 parentid)
static int add_relation_rb(struct btrfs_fs_info *fs_info,
struct btrfs_qgroup_list *prealloc,
u64 memberid, u64 parentid)
{
struct btrfs_qgroup *member;
struct btrfs_qgroup *parent;
@ -308,7 +309,7 @@ static int add_relation_rb(struct btrfs_fs_info *fs_info, u64 memberid, u64 pare
member = find_qgroup_rb(fs_info, memberid);
parent = find_qgroup_rb(fs_info, parentid);
return __add_relation_rb(member, parent);
return __add_relation_rb(prealloc, member, parent);
}
/* Must be called with qgroup_lock held */
@ -504,6 +505,8 @@ next1:
if (ret)
goto out;
while (1) {
struct btrfs_qgroup_list *list = NULL;
slot = path->slots[0];
l = path->nodes[0];
btrfs_item_key_to_cpu(l, &found_key, slot);
@ -517,8 +520,14 @@ next1:
goto next2;
}
ret = add_relation_rb(fs_info, found_key.objectid,
list = kzalloc(sizeof(*list), GFP_KERNEL);
if (!list) {
ret = -ENOMEM;
goto out;
}
ret = add_relation_rb(fs_info, list, found_key.objectid,
found_key.offset);
list = NULL;
if (ret == -ENOENT) {
btrfs_warn(fs_info,
"orphan qgroup relation 0x%llx->0x%llx",
@ -1486,6 +1495,7 @@ int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
struct btrfs_qgroup *parent;
struct btrfs_qgroup *member;
struct btrfs_qgroup_list *list;
struct btrfs_qgroup_list *prealloc = NULL;
int ret = 0;
/* Check the level of src and dst first */
@ -1512,6 +1522,11 @@ int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
}
}
prealloc = kzalloc(sizeof(*list), GFP_NOFS);
if (!prealloc) {
ret = -ENOMEM;
goto out;
}
ret = add_qgroup_relation_item(trans, src, dst);
if (ret)
goto out;
@ -1523,7 +1538,8 @@ int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
}
spin_lock(&fs_info->qgroup_lock);
ret = __add_relation_rb(member, parent);
ret = __add_relation_rb(prealloc, member, parent);
prealloc = NULL;
if (ret < 0) {
spin_unlock(&fs_info->qgroup_lock);
goto out;
@ -1531,6 +1547,7 @@ int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
ret = quick_update_accounting(fs_info, src, dst, 1);
spin_unlock(&fs_info->qgroup_lock);
out:
kfree(prealloc);
mutex_unlock(&fs_info->qgroup_ioctl_lock);
return ret;
}
@ -2887,6 +2904,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
struct btrfs_qgroup *srcgroup;
struct btrfs_qgroup *dstgroup;
struct btrfs_qgroup *prealloc;
struct btrfs_qgroup_list **qlist_prealloc = NULL;
bool need_rescan = false;
u32 level_size = 0;
u64 nums;
@ -2967,8 +2985,23 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
goto out;
}
ret = 0;
}
qlist_prealloc = kcalloc(inherit->num_qgroups,
sizeof(struct btrfs_qgroup_list *),
GFP_NOFS);
if (!qlist_prealloc) {
ret = -ENOMEM;
goto out;
}
for (int i = 0; i < inherit->num_qgroups; i++) {
qlist_prealloc[i] = kzalloc(sizeof(struct btrfs_qgroup_list),
GFP_NOFS);
if (!qlist_prealloc[i]) {
ret = -ENOMEM;
goto out;
}
}
}
spin_lock(&fs_info->qgroup_lock);
@ -3020,7 +3053,9 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
i_qgroups = (u64 *)(inherit + 1);
for (i = 0; i < inherit->num_qgroups; ++i) {
if (*i_qgroups) {
ret = add_relation_rb(fs_info, objectid, *i_qgroups);
ret = add_relation_rb(fs_info, qlist_prealloc[i], objectid,
*i_qgroups);
qlist_prealloc[i] = NULL;
if (ret)
goto unlock;
}
@ -3084,6 +3119,11 @@ out:
mutex_unlock(&fs_info->qgroup_ioctl_lock);
if (need_rescan)
qgroup_mark_inconsistent(fs_info);
if (qlist_prealloc) {
for (int i = 0; i < inherit->num_qgroups; i++)
kfree(qlist_prealloc[i]);
kfree(qlist_prealloc);
}
kfree(prealloc);
return ret;
}