diff options
Diffstat (limited to 'fs/btrfs/root-tree.c')
-rw-r--r-- | fs/btrfs/root-tree.c | 302 |
1 files changed, 180 insertions, 122 deletions
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index 24fb8ce4e071..ffb1036ef10d 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -16,58 +16,107 @@ * Boston, MA 021110-1307, USA. */ +#include <linux/uuid.h> #include "ctree.h" #include "transaction.h" #include "disk-io.h" #include "print-tree.h" /* - * lookup the root with the highest offset for a given objectid. The key we do - * find is copied into 'key'. If we find something return 0, otherwise 1, < 0 - * on error. + * Read a root item from the tree. In case we detect a root item smaller then + * sizeof(root_item), we know it's an old version of the root structure and + * initialize all new fields to zero. The same happens if we detect mismatching + * generation numbers as then we know the root was once mounted with an older + * kernel that was not aware of the root item structure change. */ -int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, - struct btrfs_root_item *item, struct btrfs_key *key) +void btrfs_read_root_item(struct extent_buffer *eb, int slot, + struct btrfs_root_item *item) +{ + uuid_le uuid; + int len; + int need_reset = 0; + + len = btrfs_item_size_nr(eb, slot); + read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot), + min_t(int, len, (int)sizeof(*item))); + if (len < sizeof(*item)) + need_reset = 1; + if (!need_reset && btrfs_root_generation(item) + != btrfs_root_generation_v2(item)) { + if (btrfs_root_generation_v2(item) != 0) { + printk(KERN_WARNING "btrfs: mismatching " + "generation and generation_v2 " + "found in root item. This root " + "was probably mounted with an " + "older kernel. Resetting all " + "new fields.\n"); + } + need_reset = 1; + } + if (need_reset) { + memset(&item->generation_v2, 0, + sizeof(*item) - offsetof(struct btrfs_root_item, + generation_v2)); + + uuid_le_gen(&uuid); + memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE); + } +} + +/* + * btrfs_find_root - lookup the root by the key. + * root: the root of the root tree + * search_key: the key to search + * path: the path we search + * root_item: the root item of the tree we look for + * root_key: the reak key of the tree we look for + * + * If ->offset of 'seach_key' is -1ULL, it means we are not sure the offset + * of the search key, just lookup the root with the highest offset for a + * given objectid. + * + * If we find something return 0, otherwise > 0, < 0 on error. + */ +int btrfs_find_root(struct btrfs_root *root, struct btrfs_key *search_key, + struct btrfs_path *path, struct btrfs_root_item *root_item, + struct btrfs_key *root_key) { - struct btrfs_path *path; - struct btrfs_key search_key; struct btrfs_key found_key; struct extent_buffer *l; int ret; int slot; - search_key.objectid = objectid; - search_key.type = BTRFS_ROOT_ITEM_KEY; - search_key.offset = (u64)-1; - - path = btrfs_alloc_path(); - if (!path) - return -ENOMEM; - ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); + ret = btrfs_search_slot(NULL, root, search_key, path, 0, 0); if (ret < 0) - goto out; + return ret; - BUG_ON(ret == 0); - if (path->slots[0] == 0) { - ret = 1; - goto out; + if (search_key->offset != -1ULL) { /* the search key is exact */ + if (ret > 0) + goto out; + } else { + BUG_ON(ret == 0); /* Logical error */ + if (path->slots[0] == 0) + goto out; + path->slots[0]--; + ret = 0; } + l = path->nodes[0]; - slot = path->slots[0] - 1; + slot = path->slots[0]; + btrfs_item_key_to_cpu(l, &found_key, slot); - if (found_key.objectid != objectid || + if (found_key.objectid != search_key->objectid || found_key.type != BTRFS_ROOT_ITEM_KEY) { ret = 1; goto out; } - if (item) - read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot), - sizeof(*item)); - if (key) - memcpy(key, &found_key, sizeof(found_key)); - ret = 0; + + if (root_item) + btrfs_read_root_item(l, slot, root_item); + if (root_key) + memcpy(root_key, &found_key, sizeof(found_key)); out: - btrfs_free_path(path); + btrfs_release_path(path); return ret; } @@ -91,6 +140,7 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root int ret; int slot; unsigned long ptr; + int old_len; path = btrfs_alloc_path(); if (!path) @@ -113,6 +163,45 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root l = path->nodes[0]; slot = path->slots[0]; ptr = btrfs_item_ptr_offset(l, slot); + old_len = btrfs_item_size_nr(l, slot); + + /* + * If this is the first time we update the root item which originated + * from an older kernel, we need to enlarge the item size to make room + * for the added fields. + */ + if (old_len < sizeof(*item)) { + btrfs_release_path(path); + ret = btrfs_search_slot(trans, root, key, path, + -1, 1); + if (ret < 0) { + btrfs_abort_transaction(trans, root, ret); + goto out; + } + + ret = btrfs_del_item(trans, root, path); + if (ret < 0) { + btrfs_abort_transaction(trans, root, ret); + goto out; + } + btrfs_release_path(path); + ret = btrfs_insert_empty_item(trans, root, path, + key, sizeof(*item)); + if (ret < 0) { + btrfs_abort_transaction(trans, root, ret); + goto out; + } + l = path->nodes[0]; + slot = path->slots[0]; + ptr = btrfs_item_ptr_offset(l, slot); + } + + /* + * Update generation_v2 so at the next mount we know the new root + * fields are valid. + */ + btrfs_set_root_generation_v2(item, btrfs_root_generation(item)); + write_extent_buffer(l, item, ptr, sizeof(*item)); btrfs_mark_buffer_dirty(path->nodes[0]); out: @@ -123,89 +212,13 @@ out: int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_key *key, struct btrfs_root_item *item) { + /* + * Make sure generation v1 and v2 match. See update_root for details. + */ + btrfs_set_root_generation_v2(item, btrfs_root_generation(item)); return btrfs_insert_item(trans, root, key, item, sizeof(*item)); } -/* - * at mount time we want to find all the old transaction snapshots that were in - * the process of being deleted if we crashed. This is any root item with an - * offset lower than the latest root. They need to be queued for deletion to - * finish what was happening when we crashed. - */ -int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid) -{ - struct btrfs_root *dead_root; - struct btrfs_root_item *ri; - struct btrfs_key key; - struct btrfs_key found_key; - struct btrfs_path *path; - int ret; - u32 nritems; - struct extent_buffer *leaf; - int slot; - - key.objectid = objectid; - btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); - key.offset = 0; - path = btrfs_alloc_path(); - if (!path) - return -ENOMEM; - -again: - ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); - if (ret < 0) - goto err; - while (1) { - leaf = path->nodes[0]; - nritems = btrfs_header_nritems(leaf); - slot = path->slots[0]; - if (slot >= nritems) { - ret = btrfs_next_leaf(root, path); - if (ret) - break; - leaf = path->nodes[0]; - nritems = btrfs_header_nritems(leaf); - slot = path->slots[0]; - } - btrfs_item_key_to_cpu(leaf, &key, slot); - if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY) - goto next; - - if (key.objectid < objectid) - goto next; - - if (key.objectid > objectid) - break; - - ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item); - if (btrfs_disk_root_refs(leaf, ri) != 0) - goto next; - - memcpy(&found_key, &key, sizeof(key)); - key.offset++; - btrfs_release_path(path); - dead_root = - btrfs_read_fs_root_no_radix(root->fs_info->tree_root, - &found_key); - if (IS_ERR(dead_root)) { - ret = PTR_ERR(dead_root); - goto err; - } - - ret = btrfs_add_dead_root(dead_root); - if (ret) - goto err; - goto again; -next: - slot++; - path->slots[0]++; - } - ret = 0; -err: - btrfs_free_path(path); - return ret; -} - int btrfs_find_orphan_roots(struct btrfs_root *tree_root) { struct extent_buffer *leaf; @@ -215,6 +228,10 @@ int btrfs_find_orphan_roots(struct btrfs_root *tree_root) struct btrfs_root *root; int err = 0; int ret; + bool can_recover = true; + + if (tree_root->fs_info->sb->s_flags & MS_RDONLY) + can_recover = false; path = btrfs_alloc_path(); if (!path) @@ -254,20 +271,52 @@ int btrfs_find_orphan_roots(struct btrfs_root *tree_root) root_key.objectid = key.offset; key.offset++; - root = btrfs_read_fs_root_no_name(tree_root->fs_info, - &root_key); - if (!IS_ERR(root)) + root = btrfs_read_fs_root(tree_root, &root_key); + err = PTR_RET(root); + if (err && err != -ENOENT) { + break; + } else if (err == -ENOENT) { + struct btrfs_trans_handle *trans; + + btrfs_release_path(path); + + trans = btrfs_join_transaction(tree_root); + if (IS_ERR(trans)) { + err = PTR_ERR(trans); + btrfs_error(tree_root->fs_info, err, + "Failed to start trans to delete " + "orphan item"); + break; + } + err = btrfs_del_orphan_item(trans, tree_root, + root_key.objectid); + btrfs_end_transaction(trans, tree_root); + if (err) { + btrfs_error(tree_root->fs_info, err, + "Failed to delete root orphan " + "item"); + break; + } continue; + } - ret = PTR_ERR(root); - if (ret != -ENOENT) { - err = ret; + if (btrfs_root_refs(&root->root_item) == 0) { + btrfs_add_dead_root(root); + continue; + } + + err = btrfs_init_fs_root(root); + if (err) { + btrfs_free_fs_root(root); break; } - ret = btrfs_find_dead_roots(tree_root, root_key.objectid); - if (ret) { - err = ret; + root->orphan_item_inserted = 1; + + err = btrfs_insert_fs_root(root->fs_info, root); + if (err) { + BUG_ON(err == -EEXIST); + btrfs_free_fs_root(root); break; } } @@ -282,8 +331,6 @@ int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, { struct btrfs_path *path; int ret; - struct btrfs_root_item *ri; - struct extent_buffer *leaf; path = btrfs_alloc_path(); if (!path) @@ -293,8 +340,6 @@ int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, goto out; BUG_ON(ret != 0); - leaf = path->nodes[0]; - ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item); ret = btrfs_del_item(trans, root, path); out: @@ -454,3 +499,16 @@ void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item) root_item->byte_limit = 0; } } + +void btrfs_update_root_times(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_root_item *item = &root->root_item; + struct timespec ct = CURRENT_TIME; + + spin_lock(&root->root_item_lock); + item->ctransid = cpu_to_le64(trans->transid); + item->ctime.sec = cpu_to_le64(ct.tv_sec); + item->ctime.nsec = cpu_to_le32(ct.tv_nsec); + spin_unlock(&root->root_item_lock); +} |