diff options
Diffstat (limited to 'fs/btrfs/tree-log.c')
-rw-r--r-- | fs/btrfs/tree-log.c | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 4920fceffacb..5c222f3c4841 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -4123,6 +4123,308 @@ static int logged_inode_size(struct btrfs_root *log, struct inode *inode, return 0; } +/* + * At the moment we always log all xattrs. This is to figure out at log replay + * time which xattrs must have their deletion replayed. If a xattr is missing + * in the log tree and exists in the fs/subvol tree, we delete it. This is + * because if a xattr is deleted, the inode is fsynced and a power failure + * happens, causing the log to be replayed the next time the fs is mounted, + * we want the xattr to not exist anymore (same behaviour as other filesystems + * with a journal, ext3/4, xfs, f2fs, etc). + */ +static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *inode, + struct btrfs_path *path, + struct btrfs_path *dst_path) +{ + int ret; + struct btrfs_key key; + const u64 ino = btrfs_ino(inode); + int ins_nr = 0; + int start_slot = 0; + + key.objectid = ino; + key.type = BTRFS_XATTR_ITEM_KEY; + key.offset = 0; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + return ret; + + while (true) { + int slot = path->slots[0]; + struct extent_buffer *leaf = path->nodes[0]; + int nritems = btrfs_header_nritems(leaf); + + if (slot >= nritems) { + if (ins_nr > 0) { + u64 last_extent = 0; + + ret = copy_items(trans, inode, dst_path, path, + &last_extent, start_slot, + ins_nr, 1, 0); + /* can't be 1, extent items aren't processed */ + ASSERT(ret <= 0); + if (ret < 0) + return ret; + ins_nr = 0; + } + ret = btrfs_next_leaf(root, path); + if (ret < 0) + return ret; + else if (ret > 0) + break; + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) + break; + + if (ins_nr == 0) + start_slot = slot; + ins_nr++; + path->slots[0]++; + cond_resched(); + } + if (ins_nr > 0) { + u64 last_extent = 0; + + ret = copy_items(trans, inode, dst_path, path, + &last_extent, start_slot, + ins_nr, 1, 0); + /* can't be 1, extent items aren't processed */ + ASSERT(ret <= 0); + if (ret < 0) + return ret; + } + + return 0; +} + +/* + * If the no holes feature is enabled we need to make sure any hole between the + * last extent and the i_size of our inode is explicitly marked in the log. This + * is to make sure that doing something like: + * + * 1) create file with 128Kb of data + * 2) truncate file to 64Kb + * 3) truncate file to 256Kb + * 4) fsync file + * 5) <crash/power failure> + * 6) mount fs and trigger log replay + * + * Will give us a file with a size of 256Kb, the first 64Kb of data match what + * the file had in its first 64Kb of data at step 1 and the last 192Kb of the + * file correspond to a hole. The presence of explicit holes in a log tree is + * what guarantees that log replay will remove/adjust file extent items in the + * fs/subvol tree. + * + * Here we do not need to care about holes between extents, that is already done + * by copy_items(). We also only need to do this in the full sync path, where we + * lookup for extents from the fs/subvol tree only. In the fast path case, we + * lookup the list of modified extent maps and if any represents a hole, we + * insert a corresponding extent representing a hole in the log tree. + */ +static int btrfs_log_trailing_hole(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *inode, + struct btrfs_path *path) +{ + int ret; + struct btrfs_key key; + u64 hole_start; + u64 hole_size; + struct extent_buffer *leaf; + struct btrfs_root *log = root->log_root; + const u64 ino = btrfs_ino(inode); + const u64 i_size = i_size_read(inode); + + if (!btrfs_fs_incompat(root->fs_info, NO_HOLES)) + return 0; + + key.objectid = ino; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = (u64)-1; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + ASSERT(ret != 0); + if (ret < 0) + return ret; + + ASSERT(path->slots[0] > 0); + path->slots[0]--; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + + if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) { + /* inode does not have any extents */ + hole_start = 0; + hole_size = i_size; + } else { + struct btrfs_file_extent_item *extent; + u64 len; + + /* + * If there's an extent beyond i_size, an explicit hole was + * already inserted by copy_items(). + */ + if (key.offset >= i_size) + return 0; + + extent = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + + if (btrfs_file_extent_type(leaf, extent) == + BTRFS_FILE_EXTENT_INLINE) { + len = btrfs_file_extent_inline_len(leaf, + path->slots[0], + extent); + ASSERT(len == i_size); + return 0; + } + + len = btrfs_file_extent_num_bytes(leaf, extent); + /* Last extent goes beyond i_size, no need to log a hole. */ + if (key.offset + len > i_size) + return 0; + hole_start = key.offset + len; + hole_size = i_size - hole_start; + } + btrfs_release_path(path); + + /* Last extent ends at i_size. */ + if (hole_size == 0) + return 0; + + hole_size = ALIGN(hole_size, root->sectorsize); + ret = btrfs_insert_file_extent(trans, log, ino, hole_start, 0, 0, + hole_size, 0, hole_size, 0, 0, 0); + 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. @@ -4295,6 +4597,41 @@ 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) + goto next_slot; + ret = copy_items(trans, inode, dst_path, path, + &last_extent, ins_start_slot, + ins_nr, inode_only, logged_isize); + if (ret < 0) { + err = ret; + goto out_unlock; + } + ins_nr = 0; + if (ret) { + btrfs_release_path(path); + continue; + } + goto next_slot; + } + src = path->nodes[0]; if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) { ins_nr++; @@ -4362,6 +4699,18 @@ next_slot: ins_nr = 0; } + btrfs_release_path(path); + btrfs_release_path(dst_path); + err = btrfs_log_all_xattrs(trans, root, inode, path, dst_path); + if (err) + goto out_unlock; + if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) { + btrfs_release_path(path); + btrfs_release_path(dst_path); + err = btrfs_log_trailing_hole(trans, root, inode, path); + if (err) + goto out_unlock; + } log_extents: btrfs_release_path(path); btrfs_release_path(dst_path); |