On Thu, Apr 12, 2012 at 05:53:15PM +0200, Jan Schmidt wrote: > Hi Mark, > > While reading 3/3 I stumbled across one more thing in this one: > > On 05.04.2012 22:09, Mark Fasheh wrote: > > +int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, > > + u64 start_off, struct btrfs_path *path, > > + struct btrfs_inode_extref **ret_ref, u64 *found_off) > > +{ > > + int ret, slot; > > + struct btrfs_key key, found_key; > > + struct btrfs_inode_extref *ref; > > + struct extent_buffer *leaf; > > + struct btrfs_item *item; > > + unsigned long ptr; > > > > -/* > > - * There are a few corners where the link count of the file can't > > - * be properly maintained during replay. So, instead of adding > > - * lots of complexity to the log code, we just scan the backrefs > > - * for any file that has been through replay. > > - * > > - * The scan will update the link count on the inode to reflect the > > - * number of back refs found. If it goes down to zero, the iput > > - * will free the inode. > > - */ > > -static noinline int fixup_inode_link_count(struct btrfs_trans_handle > > *trans, > > - struct btrfs_root *root, > > - struct inode *inode) > > + key.objectid = inode_objectid; > > + btrfs_set_key_type(&key, BTRFS_INODE_EXTREF_KEY); > > + key.offset = start_off; > > + > > + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); > > + if (ret < 0) > > + goto out; > > + > > + while (1) { > > + leaf = path->nodes[0]; > > + slot = path->slots[0]; > > + if (slot >= btrfs_header_nritems(leaf)) { > > + /* > > + * If the item at offset is not found, > > + * btrfs_search_slot will point us to the slot > > + * where it should be inserted. In our case > > + * that will be the slot directly before the > > + * next INODE_REF_KEY_V2 item. In the case > > + * that we're pointing to the last slot in a > > + * leaf, we must move one leaf over. > > + */ > > + ret = btrfs_next_leaf(root, path); > > + if (ret) { > > + if (ret >= 1) > > + ret = -ENOENT; > > + break; > > + } > > + continue; > > + } > > + > > + item = btrfs_item_nr(leaf, slot); > > + btrfs_item_key_to_cpu(leaf, &found_key, slot); > > + > > + /* > > + * Check that we're still looking at an extended ref key for > > + * this particular objectid. If we have different > > + * objectid or type then there are no more to be found > > + * in the tree and we can exit. > > + */ > > + ret = -ENOENT; > > + if (found_key.objectid != inode_objectid) > > + break; > > + if (btrfs_key_type(&found_key) != BTRFS_INODE_EXTREF_KEY) > > + break; > > + > > + ret = 0; > > + ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); > > + ref = (struct btrfs_inode_extref *)ptr; > > + *ret_ref = ref; > > + if (found_off) > > + *found_off = found_key.offset + 1; > ^^^ > It's evil to call it "found offset" an then return one larger than the > offset found. No caller would ever expect this. > > > + break; > > + } > > + > > +out: > > + return ret; > > +} > > + > > +static int count_inode_extrefs(struct btrfs_root *root, > > + struct inode *inode, struct btrfs_path *path) > > +{ > > + int ret; > > + unsigned int nlink = 0; > > + u64 inode_objectid = btrfs_ino(inode); > > + u64 offset = 0; > > + struct btrfs_inode_extref *ref; > > + > > + while (1) { > > + ret = btrfs_find_one_extref(root, inode_objectid, offset, path, > > + &ref, &offset); > > + if (ret) > > + break; > > + > > + nlink++; > > + offset++; > ^^^^^^^^ > Huh. See? The caller expected to get the offset found from > btrfs_find_one_extref. As it stands you might be missing the very next key.
Oh yeah that was totally broken btw. Fixed now, but forgot to mention that :) btrfs_find_one_extref() now returns the actual found offset (and the callers can just increment if they're doing a search). --Mark -- Mark Fasheh -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html