diff options
Diffstat (limited to 'kernel/fs/btrfs/tree-log.c')
| -rw-r--r-- | kernel/fs/btrfs/tree-log.c | 161 |
1 files changed, 145 insertions, 16 deletions
diff --git a/kernel/fs/btrfs/tree-log.c b/kernel/fs/btrfs/tree-log.c index 323e12cc9..ee7832e2d 100644 --- a/kernel/fs/btrfs/tree-log.c +++ b/kernel/fs/btrfs/tree-log.c @@ -1923,12 +1923,11 @@ static noinline int find_dir_range(struct btrfs_root *root, next: /* check the next slot in the tree to see if it is a valid item */ nritems = btrfs_header_nritems(path->nodes[0]); + path->slots[0]++; if (path->slots[0] >= nritems) { ret = btrfs_next_leaf(root, path); if (ret) goto out; - } else { - path->slots[0]++; } btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); @@ -2696,14 +2695,12 @@ static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root, int index, int error) { struct btrfs_log_ctx *ctx; + struct btrfs_log_ctx *safe; - if (!error) { - INIT_LIST_HEAD(&root->log_ctxs[index]); - return; - } - - list_for_each_entry(ctx, &root->log_ctxs[index], list) + list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) { + list_del_init(&ctx->list); ctx->log_ret = error; + } INIT_LIST_HEAD(&root->log_ctxs[index]); } @@ -2850,6 +2847,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) { blk_finish_plug(&plug); + list_del_init(&root_log_ctx.list); mutex_unlock(&log_root_tree->log_mutex); ret = root_log_ctx.log_ret; goto out; @@ -2943,13 +2941,9 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, mutex_unlock(&root->log_mutex); out_wake_log_root: - /* - * We needn't get log_mutex here because we are sure all - * the other tasks are blocked. - */ + mutex_lock(&log_root_tree->log_mutex); btrfs_remove_all_log_ctxs(log_root_tree, index2, ret); - mutex_lock(&log_root_tree->log_mutex); log_root_tree->log_transid_committed++; atomic_set(&log_root_tree->log_commit[index2], 0); mutex_unlock(&log_root_tree->log_mutex); @@ -2960,10 +2954,8 @@ out_wake_log_root: if (waitqueue_active(&log_root_tree->log_commit_wait[index2])) wake_up(&log_root_tree->log_commit_wait[index2]); out: - /* See above. */ - btrfs_remove_all_log_ctxs(root, index1, ret); - mutex_lock(&root->log_mutex); + btrfs_remove_all_log_ctxs(root, index1, ret); root->log_transid_committed++; atomic_set(&root->log_commit[index1], 0); mutex_unlock(&root->log_mutex); @@ -4406,6 +4398,127 @@ static int btrfs_log_trailing_hole(struct btrfs_trans_handle *trans, return ret; } +/* + * When we are logging a new inode X, check if it doesn't have a reference that + * matches the reference from some other inode Y created in a past transaction + * and that was renamed in the current transaction. If we don't do this, then at + * log replay time we can lose inode Y (and all its files if it's a directory): + * + * mkdir /mnt/x + * echo "hello world" > /mnt/x/foobar + * sync + * mv /mnt/x /mnt/y + * mkdir /mnt/x # or touch /mnt/x + * xfs_io -c fsync /mnt/x + * <power fail> + * mount fs, trigger log replay + * + * After the log replay procedure, we would lose the first directory and all its + * files (file foobar). + * For the case where inode Y is not a directory we simply end up losing it: + * + * echo "123" > /mnt/foo + * sync + * mv /mnt/foo /mnt/bar + * echo "abc" > /mnt/foo + * xfs_io -c fsync /mnt/foo + * <power fail> + * + * We also need this for cases where a snapshot entry is replaced by some other + * entry (file or directory) otherwise we end up with an unreplayable log due to + * attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as + * if it were a regular entry: + * + * mkdir /mnt/x + * btrfs subvolume snapshot /mnt /mnt/x/snap + * btrfs subvolume delete /mnt/x/snap + * rmdir /mnt/x + * mkdir /mnt/x + * fsync /mnt/x or fsync some new file inside it + * <power fail> + * + * The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in + * the same transaction. + */ +static int btrfs_check_ref_name_override(struct extent_buffer *eb, + const int slot, + const struct btrfs_key *key, + struct inode *inode) +{ + int ret; + struct btrfs_path *search_path; + char *name = NULL; + u32 name_len = 0; + u32 item_size = btrfs_item_size_nr(eb, slot); + u32 cur_offset = 0; + unsigned long ptr = btrfs_item_ptr_offset(eb, slot); + + search_path = btrfs_alloc_path(); + if (!search_path) + return -ENOMEM; + search_path->search_commit_root = 1; + search_path->skip_locking = 1; + + while (cur_offset < item_size) { + u64 parent; + u32 this_name_len; + u32 this_len; + unsigned long name_ptr; + struct btrfs_dir_item *di; + + if (key->type == BTRFS_INODE_REF_KEY) { + struct btrfs_inode_ref *iref; + + iref = (struct btrfs_inode_ref *)(ptr + cur_offset); + parent = key->offset; + this_name_len = btrfs_inode_ref_name_len(eb, iref); + name_ptr = (unsigned long)(iref + 1); + this_len = sizeof(*iref) + this_name_len; + } else { + struct btrfs_inode_extref *extref; + + extref = (struct btrfs_inode_extref *)(ptr + + cur_offset); + parent = btrfs_inode_extref_parent(eb, extref); + this_name_len = btrfs_inode_extref_name_len(eb, extref); + name_ptr = (unsigned long)&extref->name; + this_len = sizeof(*extref) + this_name_len; + } + + if (this_name_len > name_len) { + char *new_name; + + new_name = krealloc(name, this_name_len, GFP_NOFS); + if (!new_name) { + ret = -ENOMEM; + goto out; + } + name_len = this_name_len; + name = new_name; + } + + read_extent_buffer(eb, name, name_ptr, this_name_len); + di = btrfs_lookup_dir_item(NULL, BTRFS_I(inode)->root, + search_path, parent, + name, this_name_len, 0); + if (di && !IS_ERR(di)) { + ret = 1; + goto out; + } else if (IS_ERR(di)) { + ret = PTR_ERR(di); + goto out; + } + btrfs_release_path(search_path); + + cur_offset += this_len; + } + ret = 0; +out: + btrfs_free_path(search_path); + kfree(name); + return ret; +} + /* log a single inode in the tree log. * At least one parent directory for this inode must exist in the tree * or be logged already. @@ -4578,6 +4691,22 @@ again: if (min_key.type == BTRFS_INODE_ITEM_KEY) need_log_inode_item = false; + if ((min_key.type == BTRFS_INODE_REF_KEY || + min_key.type == BTRFS_INODE_EXTREF_KEY) && + BTRFS_I(inode)->generation == trans->transid) { + ret = btrfs_check_ref_name_override(path->nodes[0], + path->slots[0], + &min_key, inode); + if (ret < 0) { + err = ret; + goto out_unlock; + } else if (ret > 0) { + err = 1; + btrfs_set_log_full_commit(root->fs_info, trans); + goto out_unlock; + } + } + /* Skip xattrs, we log them later with btrfs_log_all_xattrs() */ if (min_key.type == BTRFS_XATTR_ITEM_KEY) { if (ins_nr == 0) |