| Message ID | 1364298930-4507-4-git-send-email-wangshilong1991@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hello Arne, I have sent a patch-set about btrfs quota, would you please review them for me. Any comment is welcome. Thanks, Wang > From: Wang Shilong <wangsl-fnst@cn.fujitsu.com> > > This is one of most important reason why we introduce a mutex here, > the previous code dosen't check 'src' and 'dst' before assigning/removing > a qgroup relations. Without the mutex lock, and checks may leads > a race conditon. > > Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com> > Reviewed-by: Miao Xie <miaox@cn.fujitsu.com> > --- > fs/btrfs/ioctl.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++- > 1 files changed, 80 insertions(+), 1 deletions(-) > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index 8a01326..1cd96f6 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -3735,6 +3735,82 @@ drop_write: > return ret; > } > > +static int may_qgroup_assign(struct btrfs_root *root, > + struct btrfs_ioctl_qgroup_assign_args *sa) > +{ > + int ret = 0; > + struct btrfs_key key; > + struct btrfs_path *path; > + > + if (!root->fs_info->quota_root) > + return -EINVAL; > + > + path = btrfs_alloc_path(); > + if (!path) { > + ret = -ENOMEM; > + return ret; > + } > + > + key.objectid = 0; > + key.type = BTRFS_QGROUP_INFO_KEY; > + key.offset = sa->src; > + ret = btrfs_search_slot(NULL, root->fs_info->quota_root, > + &key, path, 0, 0); > + if (ret > 0) > + ret = -ENOENT; > + if (ret < 0) > + goto out; > + > + btrfs_release_path(path); > + key.objectid = 0; > + key.type = BTRFS_QGROUP_INFO_KEY; > + key.offset = sa->dst; > + ret = btrfs_search_slot(NULL, root->fs_info->quota_root, > + &key, path, 0, 0); > + if (ret > 0) > + ret = -ENOENT; > + if (ret < 0) > + goto out; > + > + btrfs_release_path(path); > + key.objectid = sa->src; > + key.type = BTRFS_QGROUP_RELATION_KEY; > + key.offset = sa->dst; > + ret = btrfs_search_slot(NULL, root->fs_info->quota_root, > + &key, path, 0, 0); > + if (sa->assign) { > + if (!ret) > + ret = -EEXIST; > + if (ret < 0) > + goto out; > + } else { > + if (ret > 0) > + ret = -ENOENT; > + if (ret < 0) > + goto out; > + } > + > + btrfs_release_path(path); > + key.objectid = sa->dst; > + key.type = BTRFS_QGROUP_RELATION_KEY; > + key.offset = sa->src; > + if (sa->assign) { > + if (!ret) > + ret = -EEXIST; > + if (ret < 0) > + goto out; > + } else { > + if (ret > 0) > + ret = -ENOENT; > + if (ret < 0) > + goto out; > + } > + ret = 0; > +out: > + btrfs_free_path(path); > + return ret; > +} > + > static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg) > { > struct btrfs_root *root = BTRFS_I(file_inode(file))->root; > @@ -3757,13 +3833,16 @@ static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg) > } > > mutex_lock(&root->fs_info->quota_lock); > + ret = may_qgroup_assign(root, sa); > + if (ret) > + goto out; > + > trans = btrfs_join_transaction(root); > if (IS_ERR(trans)) { > ret = PTR_ERR(trans); > goto out; > } > > - /* FIXME: check if the IDs really exist */ > if (sa->assign) { > ret = btrfs_add_qgroup_relation(trans, root->fs_info, > sa->src, sa->dst); > -- > 1.7.7.6 > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 8a01326..1cd96f6 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3735,6 +3735,82 @@ drop_write: return ret; } +static int may_qgroup_assign(struct btrfs_root *root, + struct btrfs_ioctl_qgroup_assign_args *sa) +{ + int ret = 0; + struct btrfs_key key; + struct btrfs_path *path; + + if (!root->fs_info->quota_root) + return -EINVAL; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + return ret; + } + + key.objectid = 0; + key.type = BTRFS_QGROUP_INFO_KEY; + key.offset = sa->src; + ret = btrfs_search_slot(NULL, root->fs_info->quota_root, + &key, path, 0, 0); + if (ret > 0) + ret = -ENOENT; + if (ret < 0) + goto out; + + btrfs_release_path(path); + key.objectid = 0; + key.type = BTRFS_QGROUP_INFO_KEY; + key.offset = sa->dst; + ret = btrfs_search_slot(NULL, root->fs_info->quota_root, + &key, path, 0, 0); + if (ret > 0) + ret = -ENOENT; + if (ret < 0) + goto out; + + btrfs_release_path(path); + key.objectid = sa->src; + key.type = BTRFS_QGROUP_RELATION_KEY; + key.offset = sa->dst; + ret = btrfs_search_slot(NULL, root->fs_info->quota_root, + &key, path, 0, 0); + if (sa->assign) { + if (!ret) + ret = -EEXIST; + if (ret < 0) + goto out; + } else { + if (ret > 0) + ret = -ENOENT; + if (ret < 0) + goto out; + } + + btrfs_release_path(path); + key.objectid = sa->dst; + key.type = BTRFS_QGROUP_RELATION_KEY; + key.offset = sa->src; + if (sa->assign) { + if (!ret) + ret = -EEXIST; + if (ret < 0) + goto out; + } else { + if (ret > 0) + ret = -ENOENT; + if (ret < 0) + goto out; + } + ret = 0; +out: + btrfs_free_path(path); + return ret; +} + static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg) { struct btrfs_root *root = BTRFS_I(file_inode(file))->root; @@ -3757,13 +3833,16 @@ static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg) } mutex_lock(&root->fs_info->quota_lock); + ret = may_qgroup_assign(root, sa); + if (ret) + goto out; + trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { ret = PTR_ERR(trans); goto out; } - /* FIXME: check if the IDs really exist */ if (sa->assign) { ret = btrfs_add_qgroup_relation(trans, root->fs_info, sa->src, sa->dst);