On 27/8/19 10:05 PM, Qu Wenruo wrote:
Btrfs doesn't reuse devid, thus if we add and delete device in a loop, we can increase devid to higher value, triggering tree checker to give a false alert.Furthermore, we have dev extent verification already (after tree-checker, at mount time). So even if user had bitflip on some dev items, we can still detect it and refuse to mount. Reported-by: Anand Jain <anand.j...@oracle.com> Fixes: ab4ba2e13346 ("btrfs: tree-checker: Verify dev item") Signed-off-by: Qu Wenruo <w...@suse.com> --- Changelog: v2: - Remove devid check completely As we already have verify_one_dev_extent(). --- fs/btrfs/tree-checker.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c index 43e488f5d063..076d5b8014fb 100644 --- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -686,9 +686,7 @@ static void dev_item_err(const struct extent_buffer *eb, int slot, static int check_dev_item(struct extent_buffer *leaf, struct btrfs_key *key, int slot) { - struct btrfs_fs_info *fs_info = leaf->fs_info; 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(leaf, slot, @@ -696,12 +694,6 @@ static int check_dev_item(struct extent_buffer *leaf, key->objectid, BTRFS_DEV_ITEMS_OBJECTID); return -EUCLEAN; } - if (key->offset > max_devid) { - dev_item_err(leaf, slot, - "invalid devid: has=%llu expect=[0, %llu]", - key->offset, max_devid); - return -EUCLEAN; - } ditem = btrfs_item_ptr(leaf, slot, struct btrfs_dev_item); if (btrfs_device_id(leaf, ditem) != key->offset) { dev_item_err(leaf, slot,
Though ab4ba2e13346 didn't add BTRFS_MAX_DEVS_SYS_CHUNK, BTRFS_MAX_DEVS_SYS_CHUNK is unused now, can be deleted. The reproducer script and logs should rather be in this change log. Thanks, Anand
