On 2019/3/20 下午7:51, Johannes Thumshirn wrote:
> On 20/03/2019 07:37, Qu Wenruo wrote:
> [...]
>
>> +static int check_dev_item(struct btrfs_fs_info *fs_info,
>> + struct extent_buffer *leaf,
>> + struct btrfs_key *key, int slot)
>> +{
>> + struct btrfs_dev_item *ditem;
>> + u64 max_devid = max(BTRFS_MAX_DEVS(fs_info), BTRFS_MAX_DEVS_SYS_CHUNK);
>> +
>> + if (key->objectid != BTRFS_DEV_ITEMS_OBJECTID) {
>> + dev_item_err(fs_info, leaf, slot,
>> + "invalid objectid: has=%llu expect=%llu",
>> + key->objectid, BTRFS_DEV_ITEMS_OBJECTID);
>> + goto error;
>> + }
>> + if (key->offset > max_devid) {
>> + dev_item_err(fs_info, leaf, slot,
>> + "invalid devid: has=%llu expect=[0, %llu]",
>> + key->offset, max_devid);
>> + goto error;
>> + }
>> + ditem = btrfs_item_ptr(leaf, slot, struct btrfs_dev_item);
>> + if (btrfs_device_id(leaf, ditem) != key->offset) {
>> + dev_item_err(fs_info, leaf, slot,
>> + "devid mismatch: key has=%llu item has=%llu",
>> + key->offset, btrfs_device_id(leaf, ditem));
>> + goto error;
>> + }
>> +
>> + /*
>> + * Since btrfs device add doesn't check device size at all, we could
>> + * have device item whose size is smaller than 1M which is useless, but
>> + * still valid.
>> + * So here we can only check the obviously wrong case.
>> + */
>> + if (btrfs_device_total_bytes(leaf, ditem) == 0) {
>> + dev_item_err(fs_info, leaf, slot,
>> + "invalid total bytes: have 0");
>> + goto error;
>> + }
>> + if (btrfs_device_bytes_used(leaf, ditem) >
>> + btrfs_device_total_bytes(leaf, ditem)) {
>> + dev_item_err(fs_info, leaf, slot,
>> + "invalid bytes used: have %llu expect [0, %llu]",
>> + btrfs_device_bytes_used(leaf, ditem),
>> + btrfs_device_total_bytes(leaf, ditem));
>> + goto error;
>> + }
>> + /*
>> + * Remaining members like io_align/type/gen/dev_group aren't really
>> + * utilized.
>> + * Skip them to make later usage of them easier.
>> + */
>> + return 0;
>> +error:
>> + return -EUCLEAN;
>> +}
>> +
>
> Why aren't you directly returning -EUCLEAN instead of the gotos? There's
> no cleanup pending so the additional jump label is unnecessary.
Just a coding preference.
Will it impact the performance or compiler is clever enough to change
the goto line to return -EUCLEAN?
Thanks,
Qu
