5.4-stable review patch. If anyone has any objections, please let me know.
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From: Fedor Pchelkin pchelkin@ispras.ru
commit f03e274a8b29d1d1c1bbd7f764766cb5ca537ab7 upstream.
As clearing REF_VERIFY mount option indicates there were some errors in a ref-verify process, a ref cache is not relevant anymore and should be freed.
btrfs_free_ref_cache() requires REF_VERIFY option being set so call it just before clearing the mount option.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Reported-by: syzbot+be14ed7728594dc8bd42@syzkaller.appspotmail.com Fixes: fd708b81d972 ("Btrfs: add a extent ref verify tool") CC: stable@vger.kernel.org # 5.4+ Closes: https://lore.kernel.org/lkml/000000000000e5a65c05ee832054@google.com/ Reported-by: syzbot+c563a3c79927971f950f@syzkaller.appspotmail.com Closes: https://lore.kernel.org/lkml/0000000000007fe09705fdc6086c@google.com/ Reviewed-by: Anand Jain anand.jain@oracle.com Signed-off-by: Fedor Pchelkin pchelkin@ispras.ru Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/ref-verify.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/fs/btrfs/ref-verify.c +++ b/fs/btrfs/ref-verify.c @@ -888,8 +888,10 @@ int btrfs_ref_tree_mod(struct btrfs_fs_i out_unlock: spin_unlock(&fs_info->ref_verify_lock); out: - if (ret) + if (ret) { + btrfs_free_ref_cache(fs_info); btrfs_clear_opt(fs_info->mount_opt, REF_VERIFY); + } return ret; }
@@ -1018,8 +1020,8 @@ int btrfs_build_ref_tree(struct btrfs_fs } } if (ret) { - btrfs_clear_opt(fs_info->mount_opt, REF_VERIFY); btrfs_free_ref_cache(fs_info); + btrfs_clear_opt(fs_info->mount_opt, REF_VERIFY); } btrfs_free_path(path); return ret;