From 1f4692da951af4179a6522c6b48a09a43d37e614 Mon Sep 17 00:00:00 2001 From: Alexander Block Date: Sat, 28 Jul 2012 10:42:24 +0200 Subject: [PATCH] Btrfs: fix cur_ino < parent_ino case for send/receive When the current inodes inum is smaller then the inum of the parent directory strange things were happending due to wrong path resolution and other bugs. Fix this with a new approach for the problem. Reported-by: Alex Lyakas Signed-off-by: Alexander Block --- fs/btrfs/send.c | 390 ++++++++++++++++++------------------------------ 1 file changed, 146 insertions(+), 244 deletions(-) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 5721401548e8..a5fae484d4e1 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -107,7 +107,6 @@ struct send_ctx { int cur_inode_new; int cur_inode_new_gen; int cur_inode_deleted; - int cur_inode_first_ref_orphan; u64 cur_inode_size; u64 cur_inode_mode; @@ -2296,25 +2295,25 @@ out: * a valid path yet because we did not process the refs yet. So, the inode * is created as orphan. */ -static int send_create_inode(struct send_ctx *sctx, struct btrfs_path *path, - struct btrfs_key *key) +static int send_create_inode(struct send_ctx *sctx, u64 ino) { int ret = 0; - struct extent_buffer *eb = path->nodes[0]; - struct btrfs_inode_item *ii; struct fs_path *p; - int slot = path->slots[0]; int cmd; + u64 gen; u64 mode; + u64 rdev; -verbose_printk("btrfs: send_create_inode %llu\n", sctx->cur_ino); +verbose_printk("btrfs: send_create_inode %llu\n", ino); p = fs_path_alloc(sctx); if (!p) return -ENOMEM; - ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item); - mode = btrfs_inode_mode(eb, ii); + ret = get_inode_info(sctx->send_root, ino, NULL, &gen, &mode, NULL, + NULL, &rdev); + if (ret < 0) + goto out; if (S_ISREG(mode)) cmd = BTRFS_SEND_C_MKFILE; @@ -2339,22 +2338,22 @@ verbose_printk("btrfs: send_create_inode %llu\n", sctx->cur_ino); if (ret < 0) goto out; - ret = gen_unique_name(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); + ret = gen_unique_name(sctx, ino, gen, p); if (ret < 0) goto out; TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); - TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, sctx->cur_ino); + TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, ino); if (S_ISLNK(mode)) { fs_path_reset(p); - ret = read_symlink(sctx, sctx->send_root, sctx->cur_ino, p); + ret = read_symlink(sctx, sctx->send_root, ino, p); if (ret < 0) goto out; TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, p); } else if (S_ISCHR(mode) || S_ISBLK(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { - TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, btrfs_inode_rdev(eb, ii)); + TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, rdev); } ret = send_cmd(sctx); @@ -2368,6 +2367,92 @@ out: return ret; } +/* + * We need some special handling for inodes that get processed before the parent + * directory got created. See process_recorded_refs for details. + * This function does the check if we already created the dir out of order. + */ +static int did_create_dir(struct send_ctx *sctx, u64 dir) +{ + int ret = 0; + struct btrfs_path *path = NULL; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_key di_key; + struct extent_buffer *eb; + struct btrfs_dir_item *di; + int slot; + + path = alloc_path_for_send(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + key.objectid = dir; + key.type = BTRFS_DIR_INDEX_KEY; + key.offset = 0; + while (1) { + ret = btrfs_search_slot_for_read(sctx->send_root, &key, path, + 1, 0); + if (ret < 0) + goto out; + if (!ret) { + eb = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(eb, &found_key, slot); + } + if (ret || found_key.objectid != key.objectid || + found_key.type != key.type) { + ret = 0; + goto out; + } + + di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item); + btrfs_dir_item_key_to_cpu(eb, di, &di_key); + + if (di_key.objectid < sctx->send_progress) { + ret = 1; + goto out; + } + + key.offset = found_key.offset + 1; + btrfs_release_path(path); + } + +out: + btrfs_free_path(path); + return ret; +} + +/* + * Only creates the inode if it is: + * 1. Not a directory + * 2. Or a directory which was not created already due to out of order + * directories. See did_create_dir and process_recorded_refs for details. + */ +static int send_create_inode_if_needed(struct send_ctx *sctx) +{ + int ret; + + if (S_ISDIR(sctx->cur_inode_mode)) { + ret = did_create_dir(sctx, sctx->cur_ino); + if (ret < 0) + goto out; + if (ret) { + ret = 0; + goto out; + } + } + + ret = send_create_inode(sctx, sctx->cur_ino); + if (ret < 0) + goto out; + +out: + return ret; +} + struct recorded_ref { struct list_head list; char *dir_path; @@ -2517,160 +2602,6 @@ out: return ret; } -struct finish_unordered_dir_ctx { - struct send_ctx *sctx; - struct fs_path *cur_path; - struct fs_path *dir_path; - u64 dir_ino; - int need_delete; - int delete_pass; -}; - -int __finish_unordered_dir(int num, struct btrfs_key *di_key, - const char *name, int name_len, - const char *data, int data_len, - u8 type, void *ctx) -{ - int ret = 0; - struct finish_unordered_dir_ctx *fctx = ctx; - struct send_ctx *sctx = fctx->sctx; - u64 di_gen; - u64 di_mode; - int is_orphan = 0; - - if (di_key->objectid >= fctx->dir_ino) - goto out; - - fs_path_reset(fctx->cur_path); - - ret = get_inode_info(sctx->send_root, di_key->objectid, - NULL, &di_gen, &di_mode, NULL, NULL, NULL); - if (ret < 0) - goto out; - - ret = is_first_ref(sctx, sctx->send_root, di_key->objectid, - fctx->dir_ino, name, name_len); - if (ret < 0) - goto out; - if (ret) { - is_orphan = 1; - ret = gen_unique_name(sctx, di_key->objectid, di_gen, - fctx->cur_path); - } else { - ret = get_cur_path(sctx, di_key->objectid, di_gen, - fctx->cur_path); - } - if (ret < 0) - goto out; - - ret = fs_path_add(fctx->dir_path, name, name_len); - if (ret < 0) - goto out; - - if (!fctx->delete_pass) { - if (S_ISDIR(di_mode)) { - ret = send_rename(sctx, fctx->cur_path, - fctx->dir_path); - } else { - ret = send_link(sctx, fctx->dir_path, - fctx->cur_path); - if (is_orphan) - fctx->need_delete = 1; - } - } else if (!S_ISDIR(di_mode)) { - ret = send_unlink(sctx, fctx->cur_path); - } else { - ret = 0; - } - - fs_path_remove(fctx->dir_path); - -out: - return ret; -} - -/* - * Go through all dir items and see if we find refs which could not be created - * in the past because the dir did not exist at that time. - */ -static int finish_outoforder_dir(struct send_ctx *sctx, u64 dir, u64 dir_gen) -{ - int ret = 0; - struct btrfs_path *path = NULL; - struct btrfs_key key; - struct btrfs_key found_key; - struct extent_buffer *eb; - struct finish_unordered_dir_ctx fctx; - int slot; - - path = alloc_path_for_send(); - if (!path) { - ret = -ENOMEM; - goto out; - } - - memset(&fctx, 0, sizeof(fctx)); - fctx.sctx = sctx; - fctx.cur_path = fs_path_alloc(sctx); - fctx.dir_path = fs_path_alloc(sctx); - if (!fctx.cur_path || !fctx.dir_path) { - ret = -ENOMEM; - goto out; - } - fctx.dir_ino = dir; - - ret = get_cur_path(sctx, dir, dir_gen, fctx.dir_path); - if (ret < 0) - goto out; - - /* - * We do two passes. The first links in the new refs and the second - * deletes orphans if required. Deletion of orphans is not required for - * directory inodes, as we always have only one ref and use rename - * instead of link for those. - */ - -again: - key.objectid = dir; - key.type = BTRFS_DIR_ITEM_KEY; - key.offset = 0; - while (1) { - ret = btrfs_search_slot_for_read(sctx->send_root, &key, path, - 1, 0); - if (ret < 0) - goto out; - eb = path->nodes[0]; - slot = path->slots[0]; - btrfs_item_key_to_cpu(eb, &found_key, slot); - - if (found_key.objectid != key.objectid || - found_key.type != key.type) { - btrfs_release_path(path); - break; - } - - ret = iterate_dir_item(sctx, sctx->send_root, path, - &found_key, __finish_unordered_dir, - &fctx); - if (ret < 0) - goto out; - - key.offset = found_key.offset + 1; - btrfs_release_path(path); - } - - if (!fctx.delete_pass && fctx.need_delete) { - fctx.delete_pass = 1; - goto again; - } - -out: - btrfs_free_path(path); - fs_path_free(sctx, fctx.cur_path); - fs_path_free(sctx, fctx.dir_path); - return ret; -} - /* * This does all the move/link/unlink/rmdir magic. */ @@ -2678,6 +2609,7 @@ static int process_recorded_refs(struct send_ctx *sctx) { int ret = 0; struct recorded_ref *cur; + struct recorded_ref *cur2; struct ulist *check_dirs = NULL; struct ulist_iterator uit; struct ulist_node *un; @@ -2734,6 +2666,46 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino); } list_for_each_entry(cur, &sctx->new_refs, list) { + /* + * We may have refs where the parent directory does not exist + * yet. This happens if the parent directories inum is higher + * the the current inum. To handle this case, we create the + * parent directory out of order. But we need to check if this + * did already happen before due to other refs in the same dir. + */ + ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen); + if (ret < 0) + goto out; + if (ret == inode_state_will_create) { + ret = 0; + /* + * First check if any of the current inodes refs did + * already create the dir. + */ + list_for_each_entry(cur2, &sctx->new_refs, list) { + if (cur == cur2) + break; + if (cur2->dir == cur->dir) { + ret = 1; + break; + } + } + + /* + * If that did not happen, check if a previous inode + * did already create the dir. + */ + if (!ret) + ret = did_create_dir(sctx, cur->dir); + if (ret < 0) + goto out; + if (!ret) { + ret = send_create_inode(sctx, cur->dir); + if (ret < 0) + goto out; + } + } + /* * Check if this new ref would overwrite the first ref of * another unprocessed inode. If yes, orphanize the @@ -2768,7 +2740,7 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino); * inode, move it and update valid_path. If not, link or move * it depending on the inode mode. */ - if (is_orphan && !sctx->cur_inode_first_ref_orphan) { + if (is_orphan) { ret = send_rename(sctx, valid_path, cur->full_path); if (ret < 0) goto out; @@ -2844,35 +2816,9 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino); if (ret < 0) goto out; if (!ret) { - /* - * In case the inode was moved to a directory - * that was not created yet (see - * __record_new_ref), we can not unlink the ref - * as it will be needed later when the parent - * directory is created, so that we can move in - * the inode to the new dir. - */ - if (!is_orphan && - sctx->cur_inode_first_ref_orphan) { - ret = orphanize_inode(sctx, - sctx->cur_ino, - sctx->cur_inode_gen, - cur->full_path); - if (ret < 0) - goto out; - ret = gen_unique_name(sctx, - sctx->cur_ino, - sctx->cur_inode_gen, - valid_path); - if (ret < 0) - goto out; - is_orphan = 1; - - } else { - ret = send_unlink(sctx, cur->full_path); - if (ret < 0) - goto out; - } + ret = send_unlink(sctx, cur->full_path); + if (ret < 0) + goto out; } ret = ulist_add(check_dirs, cur->dir, cur->dir_gen, GFP_NOFS); @@ -2885,11 +2831,8 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino); * happen when a previous inode did overwrite the first ref * of this inode and no new refs were added for the current * inode. - * We can however not delete the orphan in case the inode relies - * in a directory that was not created yet (see - * __record_new_ref) */ - if (is_orphan && !sctx->cur_inode_first_ref_orphan) { + if (is_orphan) { ret = send_unlink(sctx, valid_path); if (ret < 0) goto out; @@ -2939,19 +2882,6 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino); */ sctx->send_progress = sctx->cur_ino + 1; - /* - * We may have a directory here that has pending refs which could not - * be created before (because the dir did not exist before, see - * __record_new_ref). finish_outoforder_dir will link/move the pending - * refs. - */ - if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_new) { - ret = finish_outoforder_dir(sctx, sctx->cur_ino, - sctx->cur_inode_gen); - if (ret < 0) - goto out; - } - ret = 0; out: @@ -2979,31 +2909,6 @@ static int __record_new_ref(int num, u64 dir, int index, if (ret < 0) goto out; - /* - * The parent may be non-existent at this point in time. This happens - * if the ino of the parent dir is higher then the current ino. In this - * case, we can not process this ref until the parent dir is finally - * created. If we reach the parent dir later, process_recorded_refs - * will go through all dir items and process the refs that could not be - * processed before. In case this is the first ref, we set - * cur_inode_first_ref_orphan to 1 to inform process_recorded_refs to - * keep an orphan of the inode so that it later can be used for - * link/move - */ - ret = is_inode_existent(sctx, dir, gen); - if (ret < 0) - goto out; - if (!ret) { - ret = is_first_ref(sctx, sctx->send_root, sctx->cur_ino, dir, - name->start, fs_path_len(name)); - if (ret < 0) - goto out; - if (ret) - sctx->cur_inode_first_ref_orphan = 1; - ret = 0; - goto out; - } - ret = get_cur_path(sctx, dir, gen, p); if (ret < 0) goto out; @@ -4078,7 +3983,6 @@ static int changed_inode(struct send_ctx *sctx, sctx->cur_ino = key->objectid; sctx->cur_inode_new_gen = 0; - sctx->cur_inode_first_ref_orphan = 0; sctx->send_progress = sctx->cur_ino; if (result == BTRFS_COMPARE_TREE_NEW || @@ -4115,8 +4019,7 @@ static int changed_inode(struct send_ctx *sctx, sctx->cur_inode_mode = btrfs_inode_mode( sctx->left_path->nodes[0], left_ii); if (sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) - ret = send_create_inode(sctx, sctx->left_path, - sctx->cmp_key); + ret = send_create_inode_if_needed(sctx); } else if (result == BTRFS_COMPARE_TREE_DELETED) { sctx->cur_inode_gen = right_gen; sctx->cur_inode_new = 0; @@ -4146,8 +4049,7 @@ static int changed_inode(struct send_ctx *sctx, sctx->left_path->nodes[0], left_ii); sctx->cur_inode_mode = btrfs_inode_mode( sctx->left_path->nodes[0], left_ii); - ret = send_create_inode(sctx, sctx->left_path, - sctx->cmp_key); + ret = send_create_inode_if_needed(sctx); if (ret < 0) goto out; -- 2.20.1