diff options
| author | Qu Wenruo <wqu@suse.com> | 2021-09-16 20:43:29 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-30 10:09:22 +0200 |
| commit | 381c8ce0abc018934bf8d47df1880089e36c52de (patch) | |
| tree | c1cffcb81bc7b5f13681abf0ae4ff6e22cc9a9c9 | |
| parent | d4ec140e71585db72e83bbd6393a9ffc45b9565b (diff) | |
btrfs: prevent __btrfs_dump_space_info() to underflow its free space
commit 0619b7901473c380abc05d45cf9c70bee0707db3 upstream.
It's not uncommon where __btrfs_dump_space_info() gets called
under over-commit situations.
In that case free space would underflow as total allocated space is not
enough to handle all the over-committed space.
Such underflow values can sometimes cause confusion for users enabled
enospc_debug mount option, and takes some seconds for developers to
convert the underflow value to signed result.
Just output the free space as s64 to avoid such problem.
Reported-by: Eli V <eliventer@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CAJtFHUSy4zgyhf-4d9T+KdJp9w=UgzC2A0V=VtmaeEpcGgm1-Q@mail.gmail.com/
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Anand Jain <anand.jain@oracle.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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/btrfs/space-info.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c index 90500b6c41fc..1cd39f6a9c3a 100644 --- a/fs/btrfs/space-info.c +++ b/fs/btrfs/space-info.c @@ -262,9 +262,10 @@ static void __btrfs_dump_space_info(struct btrfs_fs_info *fs_info, { lockdep_assert_held(&info->lock); - btrfs_info(fs_info, "space_info %llu has %llu free, is %sfull", + /* The free space could be negative in case of overcommit */ + btrfs_info(fs_info, "space_info %llu has %lld free, is %sfull", info->flags, - info->total_bytes - btrfs_space_info_used(info, true), + (s64)(info->total_bytes - btrfs_space_info_used(info, true)), info->full ? "" : "not "); btrfs_info(fs_info, "space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu", |