Messages in this thread Patch in this message | | | From | ChenXiaoSong <> | Subject | [PATCH v4 3/3] btrfs: qgroup: fix sleep from invalid context bug in update_qgroup_limit_item() | Date | Wed, 16 Nov 2022 01:17:09 +0800 |
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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 <chenxiaosong2@huawei.com> --- fs/btrfs/qgroup.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index ca609a70d067..f84507ca3b99 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -2867,6 +2867,8 @@ 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. @@ -2957,10 +2959,7 @@ 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 = btrfs_update_quoto_limit(trans, dstgroup, fs_info); - if (ret) - goto unlock; + update_limit = true; } if (srcid) { @@ -2987,6 +2986,7 @@ 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 = false; qgroup_dirty(fs_info, dstgroup); qgroup_dirty(fs_info, srcgroup); @@ -3055,6 +3055,11 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid, unlock: spin_unlock(&fs_info->qgroup_lock); + if (update_limit) { + err = btrfs_update_quoto_limit(trans, dstgroup, fs_info); + if (err) + ret = err; + } if (!ret) ret = btrfs_sysfs_add_one_qgroup(fs_info, dstgroup); out: -- 2.31.1
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