Syzkaller reported BUG as follows:
BUG: sleeping function called from invalid context at
include/linux/sched/mm.h:274
Call Trace:
<TASK>
dump_stack_lvl+0xcd/0x134
__might_resched.cold+0x222/0x26b
kmem_cache_alloc+0x2e7/0x3c0
update_qgroup_limit_item+0xe1/0x390
btrfs_qgroup_inherit+0x147b/0x1ee0
create_subvol+0x4eb/0x1710
btrfs_mksubvol+0xfe5/0x13f0
__btrfs_ioctl_snap_create+0x2b0/0x430
btrfs_ioctl_snap_create_v2+0x25a/0x520
btrfs_ioctl+0x2a1c/0x5ce0
__x64_sys_ioctl+0x193/0x200
do_syscall_64+0x35/0x80
Fix this by delaying the limit item updates until unlock the spin lock.
Signed-off-by: ChenXiaoSong <[email protected]>
---
fs/btrfs/qgroup.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 9334c3157c22..0071b2be6785 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2860,6 +2860,8 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
bool need_rescan = false;
u32 level_size = 0;
u64 nums;
+ bool update_limit = false;
+ int err;
/*
* There are only two callers of this function.
@@ -2950,15 +2952,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
dstgroup->max_excl = inherit->lim.max_excl;
dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
dstgroup->rsv_excl = inherit->lim.rsv_excl;
-
- ret = update_qgroup_limit_item(trans, dstgroup);
- if (ret) {
- qgroup_mark_inconsistent(fs_info);
- btrfs_info(fs_info,
- "unable to update quota limit for %llu",
- dstgroup->qgroupid);
- goto unlock;
- }
+ update_limit = true;
}
if (srcid) {
@@ -2985,6 +2979,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
dstgroup->max_excl = srcgroup->max_excl;
dstgroup->rsv_rfer = srcgroup->rsv_rfer;
dstgroup->rsv_excl = srcgroup->rsv_excl;
+ update_limit = true;
qgroup_dirty(fs_info, dstgroup);
qgroup_dirty(fs_info, srcgroup);
@@ -3053,6 +3048,16 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
unlock:
spin_unlock(&fs_info->qgroup_lock);
+ if (update_limit) {
+ err = update_qgroup_limit_item(trans, dstgroup);
+ if (err) {
+ ret = err;
+ qgroup_mark_inconsistent(fs_info);
+ btrfs_info(fs_info,
+ "unable to update quota limit for %llu",
+ dstgroup->qgroupid);
+ }
+ }
if (!ret)
ret = btrfs_sysfs_add_one_qgroup(fs_info, dstgroup);
out:
--
2.31.1
Please ignore this v3 patch, I will try to send a new version patch
according to Qu Wenruo's suggestions:
https://lore.kernel.org/all/[email protected]/
在 2022/11/11 17:20, ChenXiaoSong 写道:
> Syzkaller reported BUG as follows:
>
> BUG: sleeping function called from invalid context at
> include/linux/sched/mm.h:274
> Call Trace:
> <TASK>
> dump_stack_lvl+0xcd/0x134
> __might_resched.cold+0x222/0x26b
> kmem_cache_alloc+0x2e7/0x3c0
> update_qgroup_limit_item+0xe1/0x390
> btrfs_qgroup_inherit+0x147b/0x1ee0
> create_subvol+0x4eb/0x1710
> btrfs_mksubvol+0xfe5/0x13f0
> __btrfs_ioctl_snap_create+0x2b0/0x430
> btrfs_ioctl_snap_create_v2+0x25a/0x520
> btrfs_ioctl+0x2a1c/0x5ce0
> __x64_sys_ioctl+0x193/0x200
> do_syscall_64+0x35/0x80
>
> Fix this by delaying the limit item updates until unlock the spin lock.
>
> Signed-off-by: ChenXiaoSong <[email protected]>
> ---
> fs/btrfs/qgroup.c | 23 ++++++++++++++---------
> 1 file changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
> index 9334c3157c22..0071b2be6785 100644
> --- a/fs/btrfs/qgroup.c
> +++ b/fs/btrfs/qgroup.c
> @@ -2860,6 +2860,8 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
> bool need_rescan = false;
> u32 level_size = 0;
> u64 nums;
> + bool update_limit = false;
> + int err;
>
> /*
> * There are only two callers of this function.
> @@ -2950,15 +2952,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
> dstgroup->max_excl = inherit->lim.max_excl;
> dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
> dstgroup->rsv_excl = inherit->lim.rsv_excl;
> -
> - ret = update_qgroup_limit_item(trans, dstgroup);
> - if (ret) {
> - qgroup_mark_inconsistent(fs_info);
> - btrfs_info(fs_info,
> - "unable to update quota limit for %llu",
> - dstgroup->qgroupid);
> - goto unlock;
> - }
> + update_limit = true;
> }
>
> if (srcid) {
> @@ -2985,6 +2979,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
> dstgroup->max_excl = srcgroup->max_excl;
> dstgroup->rsv_rfer = srcgroup->rsv_rfer;
> dstgroup->rsv_excl = srcgroup->rsv_excl;
> + update_limit = true;
>
> qgroup_dirty(fs_info, dstgroup);
> qgroup_dirty(fs_info, srcgroup);
> @@ -3053,6 +3048,16 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
>
> unlock:
> spin_unlock(&fs_info->qgroup_lock);
> + if (update_limit) {
> + err = update_qgroup_limit_item(trans, dstgroup);
> + if (err) {
> + ret = err;
> + qgroup_mark_inconsistent(fs_info);
> + btrfs_info(fs_info,
> + "unable to update quota limit for %llu",
> + dstgroup->qgroupid);
> + }
> + }
> if (!ret)
> ret = btrfs_sysfs_add_one_qgroup(fs_info, dstgroup);
> out:
>