diff options
Diffstat (limited to 'fs/btrfs/ctree.c')
| -rw-r--r-- | fs/btrfs/ctree.c | 1920 |
1 files changed, 1309 insertions, 611 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 8206b390058..aeab453b8e2 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -37,17 +37,10 @@ static int balance_node_right(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *dst_buf, struct extent_buffer *src_buf); -static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, - struct btrfs_path *path, int level, int slot, - int tree_mod_log); -static void tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, +static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, + int level, int slot); +static int tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, struct extent_buffer *eb); -struct extent_buffer *read_old_tree_block(struct btrfs_root *root, u64 bytenr, - u32 blocksize, u64 parent_transid, - u64 time_seq); -struct extent_buffer *btrfs_find_old_tree_block(struct btrfs_root *root, - u64 bytenr, u32 blocksize, - u64 time_seq); struct btrfs_path *btrfs_alloc_path(void) { @@ -209,7 +202,7 @@ struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) * tree until you end up with a lock on the root. A locked buffer * is returned, with a reference held. */ -struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root) +static struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root) { struct extent_buffer *eb; @@ -231,7 +224,8 @@ struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root) static void add_root_to_dirty_list(struct btrfs_root *root) { spin_lock(&root->fs_info->trans_lock); - if (root->track_dirty && list_empty(&root->dirty_list)) { + if (test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state) && + list_empty(&root->dirty_list)) { list_add(&root->dirty_list, &root->fs_info->dirty_cowonly_roots); } @@ -253,9 +247,10 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans, int level; struct btrfs_disk_key disk_key; - WARN_ON(root->ref_cows && trans->transid != - root->fs_info->running_transaction->transid); - WARN_ON(root->ref_cows && trans->transid != root->last_trans); + WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && + trans->transid != root->fs_info->running_transaction->transid); + WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && + trans->transid != root->last_trans); level = btrfs_header_level(buf); if (level == 0) @@ -280,8 +275,7 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans, else btrfs_set_header_owner(cow, new_root_objectid); - write_extent_buffer(cow, root->fs_info->fsid, - (unsigned long)btrfs_header_fsid(cow), + write_extent_buffer(cow, root->fs_info->fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE); WARN_ON(btrfs_header_generation(buf) > trans->transid); @@ -321,7 +315,7 @@ struct tree_mod_root { struct tree_mod_elem { struct rb_node node; u64 index; /* shifted logical */ - struct seq_list elem; + u64 seq; enum mod_log_op op; /* this is used for MOD_LOG_KEY_* and MOD_LOG_MOVE_KEYS operations */ @@ -341,20 +335,55 @@ struct tree_mod_elem { struct tree_mod_root old_root; }; -static inline void -__get_tree_mod_seq(struct btrfs_fs_info *fs_info, struct seq_list *elem) +static inline void tree_mod_log_read_lock(struct btrfs_fs_info *fs_info) { - elem->seq = atomic_inc_return(&fs_info->tree_mod_seq); - list_add_tail(&elem->list, &fs_info->tree_mod_seq_list); + read_lock(&fs_info->tree_mod_log_lock); } -void btrfs_get_tree_mod_seq(struct btrfs_fs_info *fs_info, - struct seq_list *elem) +static inline void tree_mod_log_read_unlock(struct btrfs_fs_info *fs_info) +{ + read_unlock(&fs_info->tree_mod_log_lock); +} + +static inline void tree_mod_log_write_lock(struct btrfs_fs_info *fs_info) +{ + write_lock(&fs_info->tree_mod_log_lock); +} + +static inline void tree_mod_log_write_unlock(struct btrfs_fs_info *fs_info) { - elem->flags = 1; + write_unlock(&fs_info->tree_mod_log_lock); +} + +/* + * Pull a new tree mod seq number for our operation. + */ +static inline u64 btrfs_inc_tree_mod_seq(struct btrfs_fs_info *fs_info) +{ + return atomic64_inc_return(&fs_info->tree_mod_seq); +} + +/* + * This adds a new blocker to the tree mod log's blocker list if the @elem + * passed does not already have a sequence number set. So when a caller expects + * to record tree modifications, it should ensure to set elem->seq to zero + * before calling btrfs_get_tree_mod_seq. + * Returns a fresh, unused tree log modification sequence number, even if no new + * blocker was added. + */ +u64 btrfs_get_tree_mod_seq(struct btrfs_fs_info *fs_info, + struct seq_list *elem) +{ + tree_mod_log_write_lock(fs_info); spin_lock(&fs_info->tree_mod_seq_lock); - __get_tree_mod_seq(fs_info, elem); + if (!elem->seq) { + elem->seq = btrfs_inc_tree_mod_seq(fs_info); + list_add_tail(&elem->list, &fs_info->tree_mod_seq_list); + } spin_unlock(&fs_info->tree_mod_seq_lock); + tree_mod_log_write_unlock(fs_info); + + return elem->seq; } void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info, @@ -371,41 +400,40 @@ void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info, if (!seq_putting) return; - BUG_ON(!(elem->flags & 1)); spin_lock(&fs_info->tree_mod_seq_lock); list_del(&elem->list); + elem->seq = 0; list_for_each_entry(cur_elem, &fs_info->tree_mod_seq_list, list) { - if ((cur_elem->flags & 1) && cur_elem->seq < min_seq) { + if (cur_elem->seq < min_seq) { if (seq_putting > cur_elem->seq) { /* * blocker with lower sequence number exists, we * cannot remove anything from the log */ - goto out; + spin_unlock(&fs_info->tree_mod_seq_lock); + return; } min_seq = cur_elem->seq; } } + spin_unlock(&fs_info->tree_mod_seq_lock); /* * anything that's lower than the lowest existing (read: blocked) * sequence number can be removed from the tree. */ - write_lock(&fs_info->tree_mod_log_lock); + tree_mod_log_write_lock(fs_info); tm_root = &fs_info->tree_mod_log; for (node = rb_first(tm_root); node; node = next) { next = rb_next(node); tm = container_of(node, struct tree_mod_elem, node); - if (tm->elem.seq > min_seq) + if (tm->seq > min_seq) continue; rb_erase(node, tm_root); - list_del(&tm->elem.list); kfree(tm); } - write_unlock(&fs_info->tree_mod_log_lock); -out: - spin_unlock(&fs_info->tree_mod_seq_lock); + tree_mod_log_write_unlock(fs_info); } /* @@ -415,6 +443,8 @@ out: * the index is the shifted logical of the *new* root node for root replace * operations, or the shifted logical of the affected block for all other * operations. + * + * Note: must be called with write lock (tree_mod_log_write_lock). */ static noinline int __tree_mod_log_insert(struct btrfs_fs_info *fs_info, struct tree_mod_elem *tm) @@ -423,11 +453,11 @@ __tree_mod_log_insert(struct btrfs_fs_info *fs_info, struct tree_mod_elem *tm) struct rb_node **new; struct rb_node *parent = NULL; struct tree_mod_elem *cur; - int ret = 0; - BUG_ON(!tm || !tm->elem.seq); + BUG_ON(!tm); + + tm->seq = btrfs_inc_tree_mod_seq(fs_info); - write_lock(&fs_info->tree_mod_log_lock); tm_root = &fs_info->tree_mod_log; new = &tm_root->rb_node; while (*new) { @@ -437,89 +467,64 @@ __tree_mod_log_insert(struct btrfs_fs_info *fs_info, struct tree_mod_elem *tm) new = &((*new)->rb_left); else if (cur->index > tm->index) new = &((*new)->rb_right); - else if (cur->elem.seq < tm->elem.seq) + else if (cur->seq < tm->seq) new = &((*new)->rb_left); - else if (cur->elem.seq > tm->elem.seq) + else if (cur->seq > tm->seq) new = &((*new)->rb_right); - else { - kfree(tm); - ret = -EEXIST; - goto unlock; - } + else + return -EEXIST; } rb_link_node(&tm->node, parent, new); rb_insert_color(&tm->node, tm_root); -unlock: - write_unlock(&fs_info->tree_mod_log_lock); - return ret; + return 0; } +/* + * Determines if logging can be omitted. Returns 1 if it can. Otherwise, it + * returns zero with the tree_mod_log_lock acquired. The caller must hold + * this until all tree mod log insertions are recorded in the rb tree and then + * call tree_mod_log_write_unlock() to release. + */ static inline int tree_mod_dont_log(struct btrfs_fs_info *fs_info, struct extent_buffer *eb) { smp_mb(); if (list_empty(&(fs_info)->tree_mod_seq_list)) return 1; - if (!eb) - return 0; - if (btrfs_header_level(eb) == 0) + if (eb && btrfs_header_level(eb) == 0) return 1; + + tree_mod_log_write_lock(fs_info); + if (list_empty(&(fs_info)->tree_mod_seq_list)) { + tree_mod_log_write_unlock(fs_info); + return 1; + } + return 0; } -/* - * This allocates memory and gets a tree modification sequence number when - * needed. - * - * Returns 0 when no sequence number is needed, < 0 on error. - * Returns 1 when a sequence number was added. In this case, - * fs_info->tree_mod_seq_lock was acquired and must be released by the caller - * after inserting into the rb tree. - */ -static inline int tree_mod_alloc(struct btrfs_fs_info *fs_info, gfp_t flags, - struct tree_mod_elem **tm_ret) +/* Similar to tree_mod_dont_log, but doesn't acquire any locks. */ +static inline int tree_mod_need_log(const struct btrfs_fs_info *fs_info, + struct extent_buffer *eb) { - struct tree_mod_elem *tm; - int seq; - - if (tree_mod_dont_log(fs_info, NULL)) + smp_mb(); + if (list_empty(&(fs_info)->tree_mod_seq_list)) + return 0; + if (eb && btrfs_header_level(eb) == 0) return 0; - tm = *tm_ret = kzalloc(sizeof(*tm), flags); - if (!tm) - return -ENOMEM; - - tm->elem.flags = 0; - spin_lock(&fs_info->tree_mod_seq_lock); - if (list_empty(&fs_info->tree_mod_seq_list)) { - /* - * someone emptied the list while we were waiting for the lock. - * we must not add to the list, because no blocker exists. items - * are removed from the list only when the existing blocker is - * removed from the list. - */ - kfree(tm); - seq = 0; - spin_unlock(&fs_info->tree_mod_seq_lock); - } else { - __get_tree_mod_seq(fs_info, &tm->elem); - seq = tm->elem.seq; - } - - return seq; + return 1; } -static noinline int -tree_mod_log_insert_key_mask(struct btrfs_fs_info *fs_info, - struct extent_buffer *eb, int slot, - enum mod_log_op op, gfp_t flags) +static struct tree_mod_elem * +alloc_tree_mod_elem(struct extent_buffer *eb, int slot, + enum mod_log_op op, gfp_t flags) { struct tree_mod_elem *tm; - int ret; - ret = tree_mod_alloc(fs_info, flags, &tm); - if (ret <= 0) - return ret; + tm = kzalloc(sizeof(*tm), flags); + if (!tm) + return NULL; tm->index = eb->start >> PAGE_CACHE_SHIFT; if (op != MOD_LOG_KEY_ADD) { @@ -529,17 +534,37 @@ tree_mod_log_insert_key_mask(struct btrfs_fs_info *fs_info, tm->op = op; tm->slot = slot; tm->generation = btrfs_node_ptr_generation(eb, slot); + RB_CLEAR_NODE(&tm->node); - ret = __tree_mod_log_insert(fs_info, tm); - spin_unlock(&fs_info->tree_mod_seq_lock); - return ret; + return tm; } static noinline int -tree_mod_log_insert_key(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, - int slot, enum mod_log_op op) +tree_mod_log_insert_key(struct btrfs_fs_info *fs_info, + struct extent_buffer *eb, int slot, + enum mod_log_op op, gfp_t flags) { - return tree_mod_log_insert_key_mask(fs_info, eb, slot, op, GFP_NOFS); + struct tree_mod_elem *tm; + int ret; + + if (!tree_mod_need_log(fs_info, eb)) + return 0; + + tm = alloc_tree_mod_elem(eb, slot, op, flags); + if (!tm) + return -ENOMEM; + + if (tree_mod_dont_log(fs_info, eb)) { + kfree(tm); + return 0; + } + + ret = __tree_mod_log_insert(fs_info, tm); + tree_mod_log_write_unlock(fs_info); + if (ret) + kfree(tm); + + return ret; } static noinline int @@ -547,22 +572,24 @@ tree_mod_log_insert_move(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, int dst_slot, int src_slot, int nr_items, gfp_t flags) { - struct tree_mod_elem *tm; - int ret; + struct tree_mod_elem *tm = NULL; + struct tree_mod_elem **tm_list = NULL; + int ret = 0; int i; + int locked = 0; - if (tree_mod_dont_log(fs_info, eb)) + if (!tree_mod_need_log(fs_info, eb)) return 0; - for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { - ret = tree_mod_log_insert_key(fs_info, eb, i + dst_slot, - MOD_LOG_KEY_REMOVE_WHILE_MOVING); - BUG_ON(ret < 0); - } + tm_list = kzalloc(nr_items * sizeof(struct tree_mod_elem *), flags); + if (!tm_list) + return -ENOMEM; - ret = tree_mod_alloc(fs_info, flags, &tm); - if (ret <= 0) - return ret; + tm = kzalloc(sizeof(*tm), flags); + if (!tm) { + ret = -ENOMEM; + goto free_tms; + } tm->index = eb->start >> PAGE_CACHE_SHIFT; tm->slot = src_slot; @@ -570,22 +597,110 @@ tree_mod_log_insert_move(struct btrfs_fs_info *fs_info, tm->move.nr_items = nr_items; tm->op = MOD_LOG_MOVE_KEYS; + for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { + tm_list[i] = alloc_tree_mod_elem(eb, i + dst_slot, + MOD_LOG_KEY_REMOVE_WHILE_MOVING, flags); + if (!tm_list[i]) { + ret = -ENOMEM; + goto free_tms; + } + } + + if (tree_mod_dont_log(fs_info, eb)) + goto free_tms; + locked = 1; + + /* + * When we override something during the move, we log these removals. + * This can only happen when we move towards the beginning of the + * buffer, i.e. dst_slot < src_slot. + */ + for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { + ret = __tree_mod_log_insert(fs_info, tm_list[i]); + if (ret) + goto free_tms; + } + ret = __tree_mod_log_insert(fs_info, tm); - spin_unlock(&fs_info->tree_mod_seq_lock); + if (ret) + goto free_tms; + tree_mod_log_write_unlock(fs_info); + kfree(tm_list); + + return 0; +free_tms: + for (i = 0; i < nr_items; i++) { + if (tm_list[i] && !RB_EMPTY_NODE(&tm_list[i]->node)) + rb_erase(&tm_list[i]->node, &fs_info->tree_mod_log); + kfree(tm_list[i]); + } + if (locked) + tree_mod_log_write_unlock(fs_info); + kfree(tm_list); + kfree(tm); + return ret; } +static inline int +__tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, + struct tree_mod_elem **tm_list, + int nritems) +{ + int i, j; + int ret; + + for (i = nritems - 1; i >= 0; i--) { + ret = __tree_mod_log_insert(fs_info, tm_list[i]); + if (ret) { + for (j = nritems - 1; j > i; j--) + rb_erase(&tm_list[j]->node, + &fs_info->tree_mod_log); + return ret; + } + } + + return 0; +} + static noinline int tree_mod_log_insert_root(struct btrfs_fs_info *fs_info, struct extent_buffer *old_root, - struct extent_buffer *new_root, gfp_t flags) + struct extent_buffer *new_root, gfp_t flags, + int log_removal) { - struct tree_mod_elem *tm; - int ret; + struct tree_mod_elem *tm = NULL; + struct tree_mod_elem **tm_list = NULL; + int nritems = 0; + int ret = 0; + int i; - ret = tree_mod_alloc(fs_info, flags, &tm); - if (ret <= 0) - return ret; + if (!tree_mod_need_log(fs_info, NULL)) + return 0; + + if (log_removal && btrfs_header_level(old_root) > 0) { + nritems = btrfs_header_nritems(old_root); + tm_list = kzalloc(nritems * sizeof(struct tree_mod_elem *), + flags); + if (!tm_list) { + ret = -ENOMEM; + goto free_tms; + } + for (i = 0; i < nritems; i++) { + tm_list[i] = alloc_tree_mod_elem(old_root, i, + MOD_LOG_KEY_REMOVE_WHILE_FREEING, flags); + if (!tm_list[i]) { + ret = -ENOMEM; + goto free_tms; + } + } + } + + tm = kzalloc(sizeof(*tm), flags); + if (!tm) { + ret = -ENOMEM; + goto free_tms; + } tm->index = new_root->start >> PAGE_CACHE_SHIFT; tm->old_root.logical = old_root->start; @@ -593,8 +708,29 @@ tree_mod_log_insert_root(struct btrfs_fs_info *fs_info, tm->generation = btrfs_header_generation(old_root); tm->op = MOD_LOG_ROOT_REPLACE; - ret = __tree_mod_log_insert(fs_info, tm); - spin_unlock(&fs_info->tree_mod_seq_lock); + if (tree_mod_dont_log(fs_info, NULL)) + goto free_tms; + + if (tm_list) + ret = __tree_mod_log_free_eb(fs_info, tm_list, nritems); + if (!ret) + ret = __tree_mod_log_insert(fs_info, tm); + + tree_mod_log_write_unlock(fs_info); + if (ret) + goto free_tms; + kfree(tm_list); + + return ret; + +free_tms: + if (tm_list) { + for (i = 0; i < nritems; i++) + kfree(tm_list[i]); + kfree(tm_list); + } + kfree(tm); + return ret; } @@ -608,7 +744,7 @@ __tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq, struct tree_mod_elem *found = NULL; u64 index = start >> PAGE_CACHE_SHIFT; - read_lock(&fs_info->tree_mod_log_lock); + tree_mod_log_read_lock(fs_info); tm_root = &fs_info->tree_mod_log; node = tm_root->rb_node; while (node) { @@ -617,18 +753,18 @@ __tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq, node = node->rb_left; } else if (cur->index > index) { node = node->rb_right; - } else if (cur->elem.seq < min_seq) { + } else if (cur->seq < min_seq) { node = node->rb_left; } else if (!smallest) { /* we want the node with the highest seq */ if (found) - BUG_ON(found->elem.seq > cur->elem.seq); + BUG_ON(found->seq > cur->seq); found = cur; node = node->rb_left; - } else if (cur->elem.seq > min_seq) { + } else if (cur->seq > min_seq) { /* we want the node with the smallest seq */ if (found) - BUG_ON(found->elem.seq < cur->elem.seq); + BUG_ON(found->seq < cur->seq); found = cur; node = node->rb_right; } else { @@ -636,7 +772,7 @@ __tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq, break; } } - read_unlock(&fs_info->tree_mod_log_lock); + tree_mod_log_read_unlock(fs_info); return found; } @@ -664,29 +800,75 @@ tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq) return __tree_mod_log_search(fs_info, start, min_seq, 0); } -static inline void +static noinline int tree_mod_log_eb_copy(struct btrfs_fs_info *fs_info, struct extent_buffer *dst, struct extent_buffer *src, unsigned long dst_offset, unsigned long src_offset, int nr_items) { - int ret; + int ret = 0; + struct tree_mod_elem **tm_list = NULL; + struct tree_mod_elem **tm_list_add, **tm_list_rem; int i; + int locked = 0; - if (tree_mod_dont_log(fs_info, NULL)) - return; + if (!tree_mod_need_log(fs_info, NULL)) + return 0; if (btrfs_header_level(dst) == 0 && btrfs_header_level(src) == 0) - return; + return 0; + + tm_list = kzalloc(nr_items * 2 * sizeof(struct tree_mod_elem *), + GFP_NOFS); + if (!tm_list) + return -ENOMEM; - /* speed this up by single seq for all operations? */ + tm_list_add = tm_list; + tm_list_rem = tm_list + nr_items; for (i = 0; i < nr_items; i++) { - ret = tree_mod_log_insert_key(fs_info, src, i + src_offset, - MOD_LOG_KEY_REMOVE); - BUG_ON(ret < 0); - ret = tree_mod_log_insert_key(fs_info, dst, i + dst_offset, - MOD_LOG_KEY_ADD); - BUG_ON(ret < 0); + tm_list_rem[i] = alloc_tree_mod_elem(src, i + src_offset, + MOD_LOG_KEY_REMOVE, GFP_NOFS); + if (!tm_list_rem[i]) { + ret = -ENOMEM; + goto free_tms; + } + + tm_list_add[i] = alloc_tree_mod_elem(dst, i + dst_offset, + MOD_LOG_KEY_ADD, GFP_NOFS); + if (!tm_list_add[i]) { + ret = -ENOMEM; + goto free_tms; + } + } + + if (tree_mod_dont_log(fs_info, NULL)) + goto free_tms; + locked = 1; + + for (i = 0; i < nr_items; i++) { + ret = __tree_mod_log_insert(fs_info, tm_list_rem[i]); + if (ret) + goto free_tms; + ret = __tree_mod_log_insert(fs_info, tm_list_add[i]); + if (ret) + goto free_tms; } + + tree_mod_log_write_unlock(fs_info); + kfree(tm_list); + + return 0; + +free_tms: + for (i = 0; i < nr_items * 2; i++) { + if (tm_list[i] && !RB_EMPTY_NODE(&tm_list[i]->node)) + rb_erase(&tm_list[i]->node, &fs_info->tree_mod_log); + kfree(tm_list[i]); + } + if (locked) + tree_mod_log_write_unlock(fs_info); + kfree(tm_list); + + return ret; } static inline void @@ -699,45 +881,74 @@ tree_mod_log_eb_move(struct btrfs_fs_info *fs_info, struct extent_buffer *dst, BUG_ON(ret < 0); } -static inline void +static noinline void tree_mod_log_set_node_key(struct btrfs_fs_info *fs_info, - struct extent_buffer *eb, - struct btrfs_disk_key *disk_key, int slot, int atomic) + struct extent_buffer *eb, int slot, int atomic) { int ret; - ret = tree_mod_log_insert_key_mask(fs_info, eb, slot, - MOD_LOG_KEY_REPLACE, - atomic ? GFP_ATOMIC : GFP_NOFS); + ret = tree_mod_log_insert_key(fs_info, eb, slot, + MOD_LOG_KEY_REPLACE, + atomic ? GFP_ATOMIC : GFP_NOFS); BUG_ON(ret < 0); } -static void tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, - struct extent_buffer *eb) +static noinline int +tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, struct extent_buffer *eb) { + struct tree_mod_elem **tm_list = NULL; + int nritems = 0; int i; - int ret; - u32 nritems; + int ret = 0; - if (tree_mod_dont_log(fs_info, eb)) - return; + if (btrfs_header_level(eb) == 0) + return 0; + + if (!tree_mod_need_log(fs_info, NULL)) + return 0; nritems = btrfs_header_nritems(eb); - for (i = nritems - 1; i >= 0; i--) { - ret = tree_mod_log_insert_key(fs_info, eb, i, - MOD_LOG_KEY_REMOVE_WHILE_FREEING); - BUG_ON(ret < 0); + tm_list = kzalloc(nritems * sizeof(struct tree_mod_elem *), + GFP_NOFS); + if (!tm_list) + return -ENOMEM; + + for (i = 0; i < nritems; i++) { + tm_list[i] = alloc_tree_mod_elem(eb, i, + MOD_LOG_KEY_REMOVE_WHILE_FREEING, GFP_NOFS); + if (!tm_list[i]) { + ret = -ENOMEM; + goto free_tms; + } } + + if (tree_mod_dont_log(fs_info, eb)) + goto free_tms; + + ret = __tree_mod_log_free_eb(fs_info, tm_list, nritems); + tree_mod_log_write_unlock(fs_info); + if (ret) + goto free_tms; + kfree(tm_list); + + return 0; + +free_tms: + for (i = 0; i < nritems; i++) + kfree(tm_list[i]); + kfree(tm_list); + + return ret; } -static inline void +static noinline void tree_mod_log_set_root_pointer(struct btrfs_root *root, - struct extent_buffer *new_root_node) + struct extent_buffer *new_root_node, + int log_removal) { int ret; - tree_mod_log_free_eb(root->fs_info, root->node); ret = tree_mod_log_insert_root(root->fs_info, root->node, - new_root_node, GFP_NOFS); + new_root_node, GFP_NOFS, log_removal); BUG_ON(ret < 0); } @@ -753,14 +964,14 @@ int btrfs_block_can_be_shared(struct btrfs_root *root, * snapshot and the block was not allocated by tree relocation, * we know the block is not shared. */ - if (root->ref_cows && + if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) && buf != root->node && buf != root->commit_root && (btrfs_header_generation(buf) <= btrfs_root_last_snapshot(&root->root_item) || btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) return 1; #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 - if (root->ref_cows && + if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) && btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) return 1; #endif @@ -798,7 +1009,8 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, if (btrfs_block_can_be_shared(root, buf)) { ret = btrfs_lookup_extent_info(trans, root, buf->start, - buf->len, &refs, &flags); + btrfs_header_level(buf), 1, + &refs, &flags); if (ret) return ret; if (refs == 0) { @@ -844,10 +1056,12 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, BUG_ON(ret); /* -ENOMEM */ } if (new_flags != 0) { + int level = btrfs_header_level(buf); + ret = btrfs_set_disk_extent_flags(trans, root, buf->start, buf->len, - new_flags, 0); + new_flags, level, 0); if (ret) return ret; } @@ -862,12 +1076,6 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, ret = btrfs_dec_ref(trans, root, buf, 1, 1); BUG_ON(ret); /* -ENOMEM */ } - /* - * don't log freeing in case we're freeing the root node, this - * is done by tree_mod_log_set_root_pointer later - */ - if (buf != root->node && btrfs_header_level(buf) != 0) - tree_mod_log_free_eb(root->fs_info, buf); clean_tree_block(trans, root, buf); *last_ref = 1; } @@ -905,9 +1113,10 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, btrfs_assert_tree_locked(buf); - WARN_ON(root->ref_cows && trans->transid != - root->fs_info->running_transaction->transid); - WARN_ON(root->ref_cows && trans->transid != root->last_trans); + WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && + trans->transid != root->fs_info->running_transaction->transid); + WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && + trans->transid != root->last_trans); level = btrfs_header_level(buf); @@ -943,8 +1152,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, else btrfs_set_header_owner(cow, root->root_key.objectid); - write_extent_buffer(cow, root->fs_info->fsid, - (unsigned long)btrfs_header_fsid(cow), + write_extent_buffer(cow, root->fs_info->fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE); ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); @@ -953,8 +1161,11 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, return ret; } - if (root->ref_cows) - btrfs_reloc_cow_block(trans, root, buf, cow); + if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) { + ret = btrfs_reloc_cow_block(trans, root, buf, cow); + if (ret) + return ret; + } if (buf == root->node) { WARN_ON(parent && parent != buf); @@ -965,7 +1176,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, parent_start = 0; extent_buffer_get(cow); - tree_mod_log_set_root_pointer(root, cow); + tree_mod_log_set_root_pointer(root, cow, 1); rcu_assign_pointer(root->node, cow); btrfs_free_tree_block(trans, root, buf, parent_start, @@ -980,12 +1191,19 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, WARN_ON(trans->transid != btrfs_header_generation(parent)); tree_mod_log_insert_key(root->fs_info, parent, parent_slot, - MOD_LOG_KEY_REPLACE); + MOD_LOG_KEY_REPLACE, GFP_NOFS); btrfs_set_node_blockptr(parent, parent_slot, cow->start); btrfs_set_node_ptr_generation(parent, parent_slot, trans->transid); btrfs_mark_buffer_dirty(parent); + if (last_ref) { + ret = tree_mod_log_free_eb(root->fs_info, buf); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + return ret; + } + } btrfs_free_tree_block(trans, root, buf, parent_start, last_ref); } @@ -1003,15 +1221,15 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, */ static struct tree_mod_elem * __tree_mod_log_oldest_root(struct btrfs_fs_info *fs_info, - struct btrfs_root *root, u64 time_seq) + struct extent_buffer *eb_root, u64 time_seq) { struct tree_mod_elem *tm; struct tree_mod_elem *found = NULL; - u64 root_logical = root->node->start; + u64 root_logical = eb_root->start; int looped = 0; if (!time_seq) - return 0; + return NULL; /* * the very last operation that's logged for a root is the replacement @@ -1022,7 +1240,7 @@ __tree_mod_log_oldest_root(struct btrfs_fs_info *fs_info, tm = tree_mod_log_search_oldest(fs_info, root_logical, time_seq); if (!looped && !tm) - return 0; + return NULL; /* * if there are no tree operation for the oldest root, we simply * return it. this should only happen if that (old) root is at @@ -1041,7 +1259,6 @@ __tree_mod_log_oldest_root(struct btrfs_fs_info *fs_info, found = tm; root_logical = tm->old_root.logical; - BUG_ON(root_logical == root->node->start); looped = 1; } @@ -1058,8 +1275,8 @@ __tree_mod_log_oldest_root(struct btrfs_fs_info *fs_info, * time_seq). */ static void -__tree_mod_log_rewind(struct extent_buffer *eb, u64 time_seq, - struct tree_mod_elem *first_tm) +__tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, + u64 time_seq, struct tree_mod_elem *first_tm) { u32 n; struct rb_node *next; @@ -1069,7 +1286,8 @@ __tree_mod_log_rewind(struct extent_buffer *eb, u64 time_seq, unsigned long p_size = sizeof(struct btrfs_key_ptr); n = btrfs_header_nritems(eb); - while (tm && tm->elem.seq >= time_seq) { + tree_mod_log_read_lock(fs_info); + while (tm && tm->seq >= time_seq) { /* * all the operations are recorded with the operator used for * the modification. as we're going backwards, we do the @@ -1078,6 +1296,7 @@ __tree_mod_log_rewind(struct extent_buffer *eb, u64 time_seq, switch (tm->op) { case MOD_LOG_KEY_REMOVE_WHILE_FREEING: BUG_ON(tm->slot < n); + /* Fallthrough */ case MOD_LOG_KEY_REMOVE_WHILE_MOVING: case MOD_LOG_KEY_REMOVE: btrfs_set_node_key(eb, &tm->key, tm->slot); @@ -1122,12 +1341,20 @@ __tree_mod_log_rewind(struct extent_buffer *eb, u64 time_seq, if (tm->index != first_tm->index) break; } + tree_mod_log_read_unlock(fs_info); btrfs_set_header_nritems(eb, n); } +/* + * Called with eb read locked. If the buffer cannot be rewinded, the same buffer + * is returned. If rewind operations happen, a fresh buffer is returned. The + * returned buffer is always read-locked. If the returned buffer is not the + * input buffer, the lock on the input buffer is released and the input buffer + * is freed (its refcount is decremented). + */ static struct extent_buffer * -tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, - u64 time_seq) +tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct btrfs_path *path, + struct extent_buffer *eb, u64 time_seq) { struct extent_buffer *eb_rewin; struct tree_mod_elem *tm; @@ -1142,11 +1369,18 @@ tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, if (!tm) return eb; + btrfs_set_path_blocking(path); + btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); + if (tm->op == MOD_LOG_KEY_REMOVE_WHILE_FREEING) { BUG_ON(tm->slot != 0); eb_rewin = alloc_dummy_extent_buffer(eb->start, fs_info->tree_root->nodesize); - BUG_ON(!eb_rewin); + if (!eb_rewin) { + btrfs_tree_read_unlock_blocking(eb); + free_extent_buffer(eb); + return NULL; + } btrfs_set_header_bytenr(eb_rewin, eb->start); btrfs_set_header_backref_rev(eb_rewin, btrfs_header_backref_rev(eb)); @@ -1154,13 +1388,22 @@ tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, btrfs_set_header_level(eb_rewin, btrfs_header_level(eb)); } else { eb_rewin = btrfs_clone_extent_buffer(eb); - BUG_ON(!eb_rewin); + if (!eb_rewin) { + btrfs_tree_read_unlock_blocking(eb); + free_extent_buffer(eb); + return NULL; + } } - extent_buffer_get(eb_rewin); + btrfs_clear_path_blocking(path, NULL, BTRFS_READ_LOCK); + btrfs_tree_read_unlock_blocking(eb); free_extent_buffer(eb); - __tree_mod_log_rewind(eb_rewin, time_seq, tm); + extent_buffer_get(eb_rewin); + btrfs_tree_read_lock(eb_rewin); + __tree_mod_log_rewind(fs_info, eb_rewin, time_seq, tm); + WARN_ON(btrfs_header_nritems(eb_rewin) > + BTRFS_NODEPTRS_PER_BLOCK(fs_info->tree_root)); return eb_rewin; } @@ -1176,54 +1419,97 @@ static inline struct extent_buffer * get_old_root(struct btrfs_root *root, u64 time_seq) { struct tree_mod_elem *tm; - struct extent_buffer *eb; + struct extent_buffer *eb = NULL; + struct extent_buffer *eb_root; + struct extent_buffer *old; struct tree_mod_root *old_root = NULL; u64 old_generation = 0; u64 logical; + u32 blocksize; - eb = btrfs_read_lock_root_node(root); - tm = __tree_mod_log_oldest_root(root->fs_info, root, time_seq); + eb_root = btrfs_read_lock_root_node(root); + tm = __tree_mod_log_oldest_root(root->fs_info, eb_root, time_seq); if (!tm) - return root->node; + return eb_root; if (tm->op == MOD_LOG_ROOT_REPLACE) { old_root = &tm->old_root; old_generation = tm->generation; logical = old_root->logical; } else { - logical = root->node->start; + logical = eb_root->start; } tm = tree_mod_log_search(root->fs_info, logical, time_seq); - if (old_root) + if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) { + btrfs_tree_read_unlock(eb_root); + free_extent_buffer(eb_root); + blocksize = btrfs_level_size(root, old_root->level); + old = read_tree_block(root, logical, blocksize, 0); + if (WARN_ON(!old || !extent_buffer_uptodate(old))) { + free_extent_buffer(old); + btrfs_warn(root->fs_info, + "failed to read tree block %llu from get_old_root", logical); + } else { + eb = btrfs_clone_extent_buffer(old); + free_extent_buffer(old); + } + } else if (old_root) { + btrfs_tree_read_unlock(eb_root); + free_extent_buffer(eb_root); eb = alloc_dummy_extent_buffer(logical, root->nodesize); - else - eb = btrfs_clone_extent_buffer(root->node); - btrfs_tree_read_unlock(root->node); - free_extent_buffer(root->node); + } else { + btrfs_set_lock_blocking_rw(eb_root, BTRFS_READ_LOCK); + eb = btrfs_clone_extent_buffer(eb_root); + btrfs_tree_read_unlock_blocking(eb_root); + free_extent_buffer(eb_root); + } + if (!eb) return NULL; + extent_buffer_get(eb); btrfs_tree_read_lock(eb); if (old_root) { btrfs_set_header_bytenr(eb, eb->start); btrfs_set_header_backref_rev(eb, BTRFS_MIXED_BACKREF_REV); - btrfs_set_header_owner(eb, root->root_key.objectid); + btrfs_set_header_owner(eb, btrfs_header_owner(eb_root)); btrfs_set_header_level(eb, old_root->level); btrfs_set_header_generation(eb, old_generation); } if (tm) - __tree_mod_log_rewind(eb, time_seq, tm); + __tree_mod_log_rewind(root->fs_info, eb, time_seq, tm); else WARN_ON(btrfs_header_level(eb) != 0); - extent_buffer_get(eb); + WARN_ON(btrfs_header_nritems(eb) > BTRFS_NODEPTRS_PER_BLOCK(root)); return eb; } +int btrfs_old_root_level(struct btrfs_root *root, u64 time_seq) +{ + struct tree_mod_elem *tm; + int level; + struct extent_buffer *eb_root = btrfs_root_node(root); + + tm = __tree_mod_log_oldest_root(root->fs_info, eb_root, time_seq); + if (tm && tm->op == MOD_LOG_ROOT_REPLACE) { + level = tm->old_root.level; + } else { + level = btrfs_header_level(eb_root); + } + free_extent_buffer(eb_root); + + return level; +} + static inline int should_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf) { +#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS + if (unlikely(test_bit(BTRFS_ROOT_DUMMY_ROOT, &root->state))) + return 0; +#endif /* ensure we can see the force_cow */ smp_rmb(); @@ -1242,7 +1528,7 @@ static inline int should_cow_block(struct btrfs_trans_handle *trans, !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && - !root->force_cow) + !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) return 0; return 1; } @@ -1260,19 +1546,14 @@ noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, u64 search_start; int ret; - if (trans->transaction != root->fs_info->running_transaction) { - printk(KERN_CRIT "trans %llu running %llu\n", - (unsigned long long)trans->transid, - (unsigned long long) + if (trans->transaction != root->fs_info->running_transaction) + WARN(1, KERN_CRIT "trans %llu running %llu\n", + trans->transid, root->fs_info->running_transaction->transid); - WARN_ON(1); - } - if (trans->transid != root->fs_info->generation) { - printk(KERN_CRIT "trans %llu running %llu\n", - (unsigned long long)trans->transid, - (unsigned long long)root->fs_info->generation); - WARN_ON(1); - } + + if (trans->transid != root->fs_info->generation) + WARN(1, KERN_CRIT "trans %llu running %llu\n", + trans->transid, root->fs_info->generation); if (!should_cow_block(trans, root, buf)) { *cow_ret = buf; @@ -1345,7 +1626,7 @@ int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) */ int btrfs_realloc_node(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *parent, - int start_slot, int cache_only, u64 *last_ret, + int start_slot, u64 *last_ret, struct btrfs_key *progress) { struct extent_buffer *cur; @@ -1365,13 +1646,9 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans, struct btrfs_disk_key disk_key; parent_level = btrfs_header_level(parent); - if (cache_only && parent_level != 1) - return 0; - if (trans->transaction != root->fs_info->running_transaction) - WARN_ON(1); - if (trans->transid != root->fs_info->generation) - WARN_ON(1); + WARN_ON(trans->transaction != root->fs_info->running_transaction); + WARN_ON(trans->transid != root->fs_info->generation); parent_nritems = btrfs_header_nritems(parent); blocksize = btrfs_level_size(root, parent_level - 1); @@ -1414,15 +1691,13 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans, else uptodate = 0; if (!cur || !uptodate) { - if (cache_only) { - free_extent_buffer(cur); - continue; - } if (!cur) { cur = read_tree_block(root, blocknr, blocksize, gen); - if (!cur) + if (!cur || !extent_buffer_uptodate(cur)) { + free_extent_buffer(cur); return -EIO; + } } else if (!uptodate) { err = btrfs_read_buffer(cur, gen); if (err) { @@ -1587,6 +1862,8 @@ static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, struct extent_buffer *parent, int slot) { int level = btrfs_header_level(parent); + struct extent_buffer *eb; + if (slot < 0) return NULL; if (slot >= btrfs_header_nritems(parent)) @@ -1594,9 +1871,15 @@ static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, BUG_ON(level == 0); - return read_tree_block(root, btrfs_node_blockptr(parent, slot), - btrfs_level_size(root, level - 1), - btrfs_node_ptr_generation(parent, slot)); + eb = read_tree_block(root, btrfs_node_blockptr(parent, slot), + btrfs_level_size(root, level - 1), + btrfs_node_ptr_generation(parent, slot)); + if (eb && !extent_buffer_uptodate(eb)) { + free_extent_buffer(eb); + eb = NULL; + } + + return eb; } /* @@ -1661,7 +1944,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, goto enospc; } - tree_mod_log_set_root_pointer(root, child); + tree_mod_log_set_root_pointer(root, child, 1); rcu_assign_pointer(root->node, child); add_root_to_dirty_list(root); @@ -1725,7 +2008,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, if (btrfs_header_nritems(right) == 0) { clean_tree_block(trans, root, right); btrfs_tree_unlock(right); - del_ptr(trans, root, path, level + 1, pslot + 1, 1); + del_ptr(root, path, level + 1, pslot + 1); root_sub_used(root, right->len); btrfs_free_tree_block(trans, root, right, 0, 1); free_extent_buffer_stale(right); @@ -1734,7 +2017,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, struct btrfs_disk_key right_key; btrfs_node_key(right, &right_key, 0); tree_mod_log_set_node_key(root->fs_info, parent, - &right_key, pslot + 1, 0); + pslot + 1, 0); btrfs_set_node_key(parent, &right_key, pslot + 1); btrfs_mark_buffer_dirty(parent); } @@ -1769,7 +2052,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, if (btrfs_header_nritems(mid) == 0) { clean_tree_block(trans, root, mid); btrfs_tree_unlock(mid); - del_ptr(trans, root, path, level + 1, pslot, 1); + del_ptr(root, path, level + 1, pslot); root_sub_used(root, mid->len); btrfs_free_tree_block(trans, root, mid, 0, 1); free_extent_buffer_stale(mid); @@ -1778,7 +2061,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, /* update the parent key to reflect our changes */ struct btrfs_disk_key mid_key; btrfs_node_key(mid, &mid_key, 0); - tree_mod_log_set_node_key(root->fs_info, parent, &mid_key, + tree_mod_log_set_node_key(root->fs_info, parent, pslot, 0); btrfs_set_node_key(parent, &mid_key, pslot); btrfs_mark_buffer_dirty(parent); @@ -1878,7 +2161,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, orig_slot += left_nr; btrfs_node_key(mid, &disk_key, 0); tree_mod_log_set_node_key(root->fs_info, parent, - &disk_key, pslot, 0); + pslot, 0); btrfs_set_node_key(parent, &disk_key, pslot); btrfs_mark_buffer_dirty(parent); if (btrfs_header_nritems(left) > orig_slot) { @@ -1931,7 +2214,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, btrfs_node_key(right, &disk_key, 0); tree_mod_log_set_node_key(root->fs_info, parent, - &disk_key, pslot + 1, 0); + pslot + 1, 0); btrfs_set_node_key(parent, &disk_key, pslot + 1); btrfs_mark_buffer_dirty(parent); @@ -2024,12 +2307,8 @@ static void reada_for_search(struct btrfs_root *root, } } -/* - * returns -EAGAIN if it had to drop the path, or zero if everything was in - * cache - */ -static noinline int reada_for_balance(struct btrfs_root *root, - struct btrfs_path *path, int level) +static noinline void reada_for_balance(struct btrfs_root *root, + struct btrfs_path *path, int level) { int slot; int nritems; @@ -2038,12 +2317,11 @@ static noinline int reada_for_balance(struct btrfs_root *root, u64 gen; u64 block1 = 0; u64 block2 = 0; - int ret = 0; int blocksize; parent = path->nodes[level + 1]; if (!parent) - return 0; + return; nritems = btrfs_header_nritems(parent); slot = path->slots[level + 1]; @@ -2070,28 +2348,11 @@ static noinline int reada_for_balance(struct btrfs_root *root, block2 = 0; free_extent_buffer(eb); } - if (block1 || block2) { - ret = -EAGAIN; - - /* release the whole path */ - btrfs_release_path(path); - - /* read the blocks */ - if (block1) - readahead_tree_block(root, block1, blocksize, 0); - if (block2) - readahead_tree_block(root, block2, blocksize, 0); - if (block1) { - eb = read_tree_block(root, block1, blocksize, 0); - free_extent_buffer(eb); - } - if (block2) { - eb = read_tree_block(root, block2, blocksize, 0); - free_extent_buffer(eb); - } - } - return ret; + if (block1) + readahead_tree_block(root, block1, blocksize, 0); + if (block2) + readahead_tree_block(root, block2, blocksize, 0); } @@ -2205,35 +2466,28 @@ read_block_for_search(struct btrfs_trans_handle *trans, tmp = btrfs_find_tree_block(root, blocknr, blocksize); if (tmp) { /* first we do an atomic uptodate check */ - if (btrfs_buffer_uptodate(tmp, 0, 1) > 0) { - if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { - /* - * we found an up to date block without - * sleeping, return - * right away - */ - *eb_ret = tmp; - return 0; - } - /* the pages were up to date, but we failed - * the generation number check. Do a full - * read for the generation number that is correct. - * We must do this without dropping locks so - * we can trust our generation number - */ - free_extent_buffer(tmp); - btrfs_set_path_blocking(p); + if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { + *eb_ret = tmp; + return 0; + } - /* now we're allowed to do a blocking uptodate check */ - tmp = read_tree_block(root, blocknr, blocksize, gen); - if (tmp && btrfs_buffer_uptodate(tmp, gen, 0) > 0) { - *eb_ret = tmp; - return 0; - } - free_extent_buffer(tmp); - btrfs_release_path(p); - return -EIO; + /* the pages were up to date, but we failed + * the generation number check. Do a full + * read for the generation number that is correct. + * We must do this without dropping locks so + * we can trust our generation number + */ + btrfs_set_path_blocking(p); + + /* now we're allowed to do a blocking uptodate check */ + ret = btrfs_read_buffer(tmp, gen); + if (!ret) { + *eb_ret = tmp; + return 0; } + free_extent_buffer(tmp); + btrfs_release_path(p); + return -EIO; } /* @@ -2294,11 +2548,8 @@ setup_nodes_for_search(struct btrfs_trans_handle *trans, goto again; } - sret = reada_for_balance(root, p, level); - if (sret) - goto again; - btrfs_set_path_blocking(p); + reada_for_balance(root, p, level); sret = split_node(trans, root, p, level); btrfs_clear_path_blocking(p, NULL, 0); @@ -2318,11 +2569,8 @@ setup_nodes_for_search(struct btrfs_trans_handle *trans, goto again; } - sret = reada_for_balance(root, p, level); - if (sret) - goto again; - btrfs_set_path_blocking(p); + reada_for_balance(root, p, level); sret = balance_level(trans, root, p, level); btrfs_clear_path_blocking(p, NULL, 0); @@ -2345,6 +2593,83 @@ done: return ret; } +static void key_search_validate(struct extent_buffer *b, + struct btrfs_key *key, + int level) +{ +#ifdef CONFIG_BTRFS_ASSERT + struct btrfs_disk_key disk_key; + + btrfs_cpu_key_to_disk(&disk_key, key); + + if (level == 0) + ASSERT(!memcmp_extent_buffer(b, &disk_key, + offsetof(struct btrfs_leaf, items[0].key), + sizeof(disk_key))); + else + ASSERT(!memcmp_extent_buffer(b, &disk_key, + offsetof(struct btrfs_node, ptrs[0].key), + sizeof(disk_key))); +#endif +} + +static int key_search(struct extent_buffer *b, struct btrfs_key *key, + int level, int *prev_cmp, int *slot) +{ + if (*prev_cmp != 0) { + *prev_cmp = bin_search(b, key, level, slot); + return *prev_cmp; + } + + key_search_validate(b, key, level); + *slot = 0; + + return 0; +} + +int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *found_path, + u64 iobjectid, u64 ioff, u8 key_type, + struct btrfs_key *found_key) +{ + int ret; + struct btrfs_key key; + struct extent_buffer *eb; + struct btrfs_path *path; + + key.type = key_type; + key.objectid = iobjectid; + key.offset = ioff; + + if (found_path == NULL) { + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + } else + path = found_path; + + ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); + if ((ret < 0) || (found_key == NULL)) { + if (path != found_path) + btrfs_free_path(path); + return ret; + } + + eb = path->nodes[0]; + if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { + ret = btrfs_next_leaf(fs_root, path); + if (ret) + return ret; + eb = path->nodes[0]; + } + + btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); + if (found_key->type != key.type || + found_key->objectid != key.objectid) + return 1; + + return 0; +} + /* * look for key in the tree. path is filled in with nodes along the way * if key is found, we return zero and you can find the item in the leaf @@ -2373,10 +2698,12 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root int write_lock_level = 0; u8 lowest_level = 0; int min_write_lock_level; + int prev_cmp; lowest_level = p->lowest_level; WARN_ON(lowest_level && ins_len > 0); WARN_ON(p->nodes[0] != NULL); + BUG_ON(!cow && ins_len); if (ins_len < 0) { lowest_unlock = 2; @@ -2403,6 +2730,7 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root min_write_lock_level = write_lock_level; again: + prev_cmp = -1; /* * we try very hard to do read locks on the root */ @@ -2413,9 +2741,13 @@ again: * the commit roots are read only * so we always do read locks */ + if (p->need_commit_sem) + down_read(&root->fs_info->commit_root_sem); b = root->commit_root; extent_buffer_get(b); level = btrfs_header_level(b); + if (p->need_commit_sem) + up_read(&root->fs_info->commit_root_sem); if (!p->skip_locking) btrfs_tree_read_lock(b); } else { @@ -2466,7 +2798,10 @@ again: * must have write locks on this node and the * parent */ - if (level + 1 > write_lock_level) { + if (level > write_lock_level || + (level + 1 > write_lock_level && + level + 1 < BTRFS_MAX_LEVEL && + p->nodes[level + 1])) { write_lock_level = level + 1; btrfs_release_path(p); goto again; @@ -2481,8 +2816,6 @@ again: } } cow_done: - BUG_ON(!cow && ins_len); - p->nodes[level] = b; btrfs_clear_path_blocking(p, NULL, 0); @@ -2492,15 +2825,21 @@ cow_done: * It is safe to drop the lock on our parent before we * go through the expensive btree search on b. * - * If cow is true, then we might be changing slot zero, - * which may require changing the parent. So, we can't - * drop the lock until after we know which slot we're - * operating on. + * If we're inserting or deleting (ins_len != 0), then we might + * be changing slot zero, which may require changing the parent. + * So, we can't drop the lock until after we know which slot + * we're operating on. */ - if (!cow) - btrfs_unlock_up_safe(p, level + 1); + if (!ins_len && !p->keep_locks) { + int u = level + 1; - ret = bin_search(b, key, level, &slot); + if (u < BTRFS_MAX_LEVEL && p->locks[u]) { + btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); + p->locks[u] = 0; + } + } + + ret = key_search(b, key, level, &prev_cmp, &slot); if (level != 0) { int dec = 0; @@ -2526,7 +2865,7 @@ cow_done: * which means we must have a write lock * on the parent */ - if (slot == 0 && cow && + if (slot == 0 && ins_len && write_lock_level < level + 1) { write_lock_level = level + 1; btrfs_release_path(p); @@ -2635,6 +2974,7 @@ int btrfs_search_old_slot(struct btrfs_root *root, struct btrfs_key *key, int level; int lowest_unlock = 1; u8 lowest_level = 0; + int prev_cmp = -1; lowest_level = p->lowest_level; WARN_ON(p->nodes[0] != NULL); @@ -2662,7 +3002,12 @@ again: */ btrfs_unlock_up_safe(p, level + 1); - ret = bin_search(b, key, level, &slot); + /* + * Since we can unwind eb's we want to do a real search every + * time. + */ + prev_cmp = -1; + ret = key_search(b, key, level, &prev_cmp, &slot); if (level != 0) { int dec = 0; @@ -2696,15 +3041,13 @@ again: btrfs_clear_path_blocking(p, b, BTRFS_READ_LOCK); } + b = tree_mod_log_rewind(root->fs_info, p, b, time_seq); + if (!b) { + ret = -ENOMEM; + goto done; + } p->locks[level] = BTRFS_READ_LOCK; p->nodes[level] = b; - b = tree_mod_log_rewind(root->fs_info, b, time_seq); - if (b != p->nodes[level]) { - btrfs_tree_unlock_rw(p->nodes[level], - p->locks[level]); - p->locks[level] = 0; - p->nodes[level] = b; - } } else { p->slots[level] = slot; unlock_up(p, level, lowest_unlock, 0, NULL); @@ -2722,6 +3065,82 @@ done: } /* + * helper to use instead of search slot if no exact match is needed but + * instead the next or previous item should be returned. + * When find_higher is true, the next higher item is returned, the next lower + * otherwise. + * When return_any and find_higher are both true, and no higher item is found, + * return the next lower instead. + * When return_any is true and find_higher is false, and no lower item is found, + * return the next higher instead. + * It returns 0 if any item is found, 1 if none is found (tree empty), and + * < 0 on error + */ +int btrfs_search_slot_for_read(struct btrfs_root *root, + struct btrfs_key *key, struct btrfs_path *p, + int find_higher, int return_any) +{ + int ret; + struct extent_buffer *leaf; + +again: + ret = btrfs_search_slot(NULL, root, key, p, 0, 0); + if (ret <= 0) + return ret; + /* + * a return value of 1 means the path is at the position where the + * item should be inserted. Normally this is the next bigger item, + * but in case the previous item is the last in a leaf, path points + * to the first free slot in the previous leaf, i.e. at an invalid + * item. + */ + leaf = p->nodes[0]; + + if (find_higher) { + if (p->slots[0] >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, p); + if (ret <= 0) + return ret; + if (!return_any) + return 1; + /* + * no higher item found, return the next + * lower instead + */ + return_any = 0; + find_higher = 0; + btrfs_release_path(p); + goto again; + } + } else { + if (p->slots[0] == 0) { + ret = btrfs_prev_leaf(root, p); + if (ret < 0) + return ret; + if (!ret) { + leaf = p->nodes[0]; + if (p->slots[0] == btrfs_header_nritems(leaf)) + p->slots[0]--; + return 0; + } + if (!return_any) + return 1; + /* + * no lower item found, return the next + * higher instead + */ + return_any = 0; + find_higher = 1; + btrfs_release_path(p); + goto again; + } else { + --p->slots[0]; + } + } + return 0; +} + +/* * adjust the pointers going up the tree, starting at level * making sure the right key of each node is points to 'key'. * This is used after shifting pointers to the left, so it stops @@ -2729,8 +3148,7 @@ done: * higher levels * */ -static void fixup_low_keys(struct btrfs_trans_handle *trans, - struct btrfs_root *root, struct btrfs_path *path, +static void fixup_low_keys(struct btrfs_root *root, struct btrfs_path *path, struct btrfs_disk_key *key, int level) { int i; @@ -2741,7 +3159,7 @@ static void fixup_low_keys(struct btrfs_trans_handle *trans, if (!path->nodes[i]) break; t = path->nodes[i]; - tree_mod_log_set_node_key(root->fs_info, t, key, tslot, 1); + tree_mod_log_set_node_key(root->fs_info, t, tslot, 1); btrfs_set_node_key(t, key, tslot); btrfs_mark_buffer_dirty(path->nodes[i]); if (tslot != 0) @@ -2755,8 +3173,7 @@ static void fixup_low_keys(struct btrfs_trans_handle *trans, * This function isn't completely safe. It's the caller's responsibility * that the new key won't break the order */ -void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, - struct btrfs_root *root, struct btrfs_path *path, +void btrfs_set_item_key_safe(struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *new_key) { struct btrfs_disk_key disk_key; @@ -2778,7 +3195,7 @@ void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, btrfs_set_item_key(eb, &disk_key, slot); btrfs_mark_buffer_dirty(eb); if (slot == 0) - fixup_low_keys(trans, root, path, &disk_key, 1); + fixup_low_keys(root, path, &disk_key, 1); } /* @@ -2824,16 +3241,22 @@ static int push_node_left(struct btrfs_trans_handle *trans, } else push_items = min(src_nritems - 8, push_items); - tree_mod_log_eb_copy(root->fs_info, dst, src, dst_nritems, 0, - push_items); + ret = tree_mod_log_eb_copy(root->fs_info, dst, src, dst_nritems, 0, + push_items); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + return ret; + } copy_extent_buffer(dst, src, btrfs_node_key_ptr_offset(dst_nritems), btrfs_node_key_ptr_offset(0), push_items * sizeof(struct btrfs_key_ptr)); if (push_items < src_nritems) { - tree_mod_log_eb_move(root->fs_info, src, 0, push_items, - src_nritems - push_items); + /* + * don't call tree_mod_log_eb_move here, key removal was already + * fully logged by tree_mod_log_eb_copy above. + */ memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), btrfs_node_key_ptr_offset(push_items), (src_nritems - push_items) * @@ -2893,8 +3316,12 @@ static int balance_node_right(struct btrfs_trans_handle *trans, (dst_nritems) * sizeof(struct btrfs_key_ptr)); - tree_mod_log_eb_copy(root->fs_info, dst, src, 0, - src_nritems - push_items, push_items); + ret = tree_mod_log_eb_copy(root->fs_info, dst, src, 0, + src_nritems - push_items, push_items); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + return ret; + } copy_extent_buffer(dst, src, btrfs_node_key_ptr_offset(0), btrfs_node_key_ptr_offset(src_nritems - push_items), @@ -2951,13 +3378,11 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans, btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); btrfs_set_header_owner(c, root->root_key.objectid); - write_extent_buffer(c, root->fs_info->fsid, - (unsigned long)btrfs_header_fsid(c), + write_extent_buffer(c, root->fs_info->fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE); write_extent_buffer(c, root->fs_info->chunk_tree_uuid, - (unsigned long)btrfs_header_chunk_tree_uuid(c), - BTRFS_UUID_SIZE); + btrfs_header_chunk_tree_uuid(c), BTRFS_UUID_SIZE); btrfs_set_node_key(c, &lower_key, 0); btrfs_set_node_blockptr(c, 0, lower->start); @@ -2969,7 +3394,7 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans, btrfs_mark_buffer_dirty(c); old = root->node; - tree_mod_log_set_root_pointer(root, c); + tree_mod_log_set_root_pointer(root, c, 0); rcu_assign_pointer(root->node, c); /* the super has an extra ref to root->node */ @@ -3016,7 +3441,7 @@ static void insert_ptr(struct btrfs_trans_handle *trans, } if (level) { ret = tree_mod_log_insert_key(root->fs_info, lower, slot, - MOD_LOG_KEY_ADD); + MOD_LOG_KEY_ADD, GFP_NOFS); BUG_ON(ret < 0); } btrfs_set_node_key(lower, key, slot); @@ -3050,7 +3475,16 @@ static noinline int split_node(struct btrfs_trans_handle *trans, c = path->nodes[level]; WARN_ON(btrfs_header_generation(c) != trans->transid); if (c == root->node) { - /* trying to split the root, lets make a new one */ + /* + * trying to split the root, lets make a new one + * + * tree mod log: We don't log_removal old root in + * insert_new_root, because that root buffer will be kept as a + * normal node. We are going to log removal of half of the + * elements below with tree_mod_log_eb_copy. We're holding a + * tree lock on the buffer, which is why we cannot race with + * other tree_mod_log users. + */ ret = insert_new_root(trans, root, path, level + 1); if (ret) return ret; @@ -3083,13 +3517,17 @@ static noinline int split_node(struct btrfs_trans_handle *trans, btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); btrfs_set_header_owner(split, root->root_key.objectid); write_extent_buffer(split, root->fs_info->fsid, - (unsigned long)btrfs_header_fsid(split), - BTRFS_FSID_SIZE); + btrfs_header_fsid(), BTRFS_FSID_SIZE); write_extent_buffer(split, root->fs_info->chunk_tree_uuid, - (unsigned long)btrfs_header_chunk_tree_uuid(split), + btrfs_header_chunk_tree_uuid(split), BTRFS_UUID_SIZE); - tree_mod_log_eb_copy(root->fs_info, split, c, 0, mid, c_nritems - mid); + ret = tree_mod_log_eb_copy(root->fs_info, split, c, 0, + mid, c_nritems - mid); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + return ret; + } copy_extent_buffer(split, c, btrfs_node_key_ptr_offset(0), btrfs_node_key_ptr_offset(mid), @@ -3124,14 +3562,21 @@ static noinline int split_node(struct btrfs_trans_handle *trans, */ static int leaf_space_used(struct extent_buffer *l, int start, int nr) { + struct btrfs_item *start_item; + struct btrfs_item *end_item; + struct btrfs_map_token token; int data_len; int nritems = btrfs_header_nritems(l); int end = min(nritems, start + nr) - 1; if (!nr) return 0; - data_len = btrfs_item_end_nr(l, start); - data_len = data_len - btrfs_item_offset_nr(l, end); + btrfs_init_map_token(&token); + start_item = btrfs_item_nr(start); + end_item = btrfs_item_nr(end); + data_len = btrfs_token_item_offset(l, start_item, &token) + + btrfs_token_item_size(l, start_item, &token); + data_len = data_len - btrfs_token_item_offset(l, end_item, &token); data_len += sizeof(struct btrfs_item) * nr; WARN_ON(data_len < 0); return data_len; @@ -3149,8 +3594,8 @@ noinline int btrfs_leaf_free_space(struct btrfs_root *root, int ret; ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); if (ret < 0) { - printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, " - "used %d nritems %d\n", + btrfs_crit(root->fs_info, + "leaf free space ret %d, leaf data size %lu, used %d nritems %d", ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), leaf_space_used(leaf, 0, nritems), nritems); } @@ -3196,7 +3641,7 @@ static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, slot = path->slots[1]; i = left_nritems - 1; while (i >= nr) { - item = btrfs_item_nr(left, i); + item = btrfs_item_nr(i); if (!empty && push_items > 0) { if (path->slots[0] > i) @@ -3225,8 +3670,7 @@ static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, if (push_items == 0) goto out_unlock; - if (!empty && push_items == left_nritems) - WARN_ON(1); + WARN_ON(!empty && push_items == left_nritems); /* push left to right */ right_nritems = btrfs_header_nritems(right); @@ -3261,7 +3705,7 @@ static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, btrfs_set_header_nritems(right, right_nritems); push_space = BTRFS_LEAF_DATA_SIZE(root); for (i = 0; i < right_nritems; i++) { - item = btrfs_item_nr(right, i); + item = btrfs_item_nr(i); push_space -= btrfs_token_item_size(right, item, &token); btrfs_set_token_item_offset(right, item, push_space, &token); } @@ -3359,6 +3803,19 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root if (left_nritems == 0) goto out_unlock; + if (path->slots[0] == left_nritems && !empty) { + /* Key greater than all keys in the leaf, right neighbor has + * enough room for it and we're not emptying our leaf to delete + * it, therefore use right neighbor to insert the new item and + * no need to touch/dirty our left leaft. */ + btrfs_tree_unlock(left); + free_extent_buffer(left); + path->nodes[0] = right; + path->slots[0] = 0; + path->slots[1]++; + return 0; + } + return __push_leaf_right(trans, root, path, min_data_size, empty, right, free_space, left_nritems, min_slot); out_unlock: @@ -3403,7 +3860,7 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, nr = min(right_nritems - 1, max_slot); for (i = 0; i < nr; i++) { - item = btrfs_item_nr(right, i); + item = btrfs_item_nr(i); if (!empty && push_items > 0) { if (path->slots[0] < i) @@ -3430,8 +3887,7 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, ret = 1; goto out; } - if (!empty && push_items == btrfs_header_nritems(right)) - WARN_ON(1); + WARN_ON(!empty && push_items == btrfs_header_nritems(right)); /* push data from right to left */ copy_extent_buffer(left, right, @@ -3454,7 +3910,7 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { u32 ioff; - item = btrfs_item_nr(left, i); + item = btrfs_item_nr(i); ioff = btrfs_token_item_offset(left, item, &token); btrfs_set_token_item_offset(left, item, @@ -3464,11 +3920,9 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, btrfs_set_header_nritems(left, old_left_nritems + push_items); /* fixup right node */ - if (push_items > right_nritems) { - printk(KERN_CRIT "push items %d nr %u\n", push_items, + if (push_items > right_nritems) + WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, right_nritems); - WARN_ON(1); - } if (push_items < right_nritems) { push_space = btrfs_item_offset_nr(right, push_items - 1) - @@ -3487,7 +3941,7 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, btrfs_set_header_nritems(right, right_nritems); push_space = BTRFS_LEAF_DATA_SIZE(root); for (i = 0; i < right_nritems; i++) { - item = btrfs_item_nr(right, i); + item = btrfs_item_nr(i); push_space = push_space - btrfs_token_item_size(right, item, &token); @@ -3501,7 +3955,7 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, clean_tree_block(trans, root, right); btrfs_item_key(right, &disk_key, 0); - fixup_low_keys(trans, root, path, &disk_key, 1); + fixup_low_keys(root, path, &disk_key, 1); /* then fixup the leaf pointer in the path */ if (path->slots[0] < push_items) { @@ -3628,7 +4082,7 @@ static noinline void copy_for_split(struct btrfs_trans_handle *trans, btrfs_item_end_nr(l, mid); for (i = 0; i < nritems; i++) { - struct btrfs_item *item = btrfs_item_nr(right, i); + struct btrfs_item *item = btrfs_item_nr(i); u32 ioff; ioff = btrfs_token_item_offset(right, item, &token); @@ -3678,14 +4132,17 @@ static noinline int push_for_double_split(struct btrfs_trans_handle *trans, int progress = 0; int slot; u32 nritems; + int space_needed = data_size; slot = path->slots[0]; + if (slot < btrfs_header_nritems(path->nodes[0])) + space_needed -= btrfs_leaf_free_space(root, path->nodes[0]); /* * try to push all the items after our slot into the * right leaf */ - ret = push_leaf_right(trans, root, path, 1, data_size, 0, slot); + ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot); if (ret < 0) return ret; @@ -3705,7 +4162,7 @@ static noinline int push_for_double_split(struct btrfs_trans_handle *trans, /* try to push all the items before our slot into the next leaf */ slot = path->slots[0]; - ret = push_leaf_left(trans, root, path, 1, data_size, 0, slot); + ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot); if (ret < 0) return ret; @@ -3748,14 +4205,19 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans, return -EOVERFLOW; /* first try to make some room by pushing left and right */ - if (data_size) { - wret = push_leaf_right(trans, root, path, data_size, - data_size, 0, 0); + if (data_size && path->nodes[1]) { + int space_needed = data_size; + + if (slot < btrfs_header_nritems(l)) + space_needed -= btrfs_leaf_free_space(root, l); + + wret = push_leaf_right(trans, root, path, space_needed, + space_needed, 0, 0); if (wret < 0) return wret; if (wret) { - wret = push_leaf_left(trans, root, path, data_size, - data_size, 0, (u32)-1); + wret = push_leaf_left(trans, root, path, space_needed, + space_needed, 0, (u32)-1); if (wret < 0) return wret; } @@ -3809,7 +4271,7 @@ again: data_size > BTRFS_LEAF_DATA_SIZE(root)) { if (data_size && !tried_avoid_double) goto push_for_double; - split = 2 ; + split = 2; } } } @@ -3835,11 +4297,10 @@ again: btrfs_set_header_owner(right, root->root_key.objectid); btrfs_set_header_level(right, 0); write_extent_buffer(right, root->fs_info->fsid, - (unsigned long)btrfs_header_fsid(right), - BTRFS_FSID_SIZE); + btrfs_header_fsid(), BTRFS_FSID_SIZE); write_extent_buffer(right, root->fs_info->chunk_tree_uuid, - (unsigned long)btrfs_header_chunk_tree_uuid(right), + btrfs_header_chunk_tree_uuid(right), BTRFS_UUID_SIZE); if (split == 0) { @@ -3861,8 +4322,7 @@ again: path->nodes[0] = right; path->slots[0] = 0; if (path->slots[1] == 0) - fixup_low_keys(trans, root, path, - &disk_key, 1); + fixup_low_keys(root, path, &disk_key, 1); } btrfs_mark_buffer_dirty(right); return ret; @@ -3972,7 +4432,7 @@ static noinline int split_item(struct btrfs_trans_handle *trans, btrfs_set_path_blocking(path); - item = btrfs_item_nr(leaf, path->slots[0]); + item = btrfs_item_nr(path->slots[0]); orig_offset = btrfs_item_offset(leaf, item); item_size = btrfs_item_size(leaf, item); @@ -3995,7 +4455,7 @@ static noinline int split_item(struct btrfs_trans_handle *trans, btrfs_cpu_key_to_disk(&disk_key, new_key); btrfs_set_item_key(leaf, &disk_key, slot); - new_item = btrfs_item_nr(leaf, slot); + new_item = btrfs_item_nr(slot); btrfs_set_item_offset(leaf, new_item, orig_offset); btrfs_set_item_size(leaf, new_item, item_size - split_offset); @@ -4078,7 +4538,7 @@ int btrfs_duplicate_item(struct btrfs_trans_handle *trans, return ret; path->slots[0]++; - setup_items_for_insert(trans, root, path, new_key, &item_size, + setup_items_for_insert(root, path, new_key, &item_size, item_size, item_size + sizeof(struct btrfs_item), 1); leaf = path->nodes[0]; @@ -4095,9 +4555,7 @@ int btrfs_duplicate_item(struct btrfs_trans_handle *trans, * off the end of the item or if we shift the item to chop bytes off * the front. */ -void btrfs_truncate_item(struct btrfs_trans_handle *trans, - struct btrfs_root *root, - struct btrfs_path *path, +void btrfs_truncate_item(struct btrfs_root *root, struct btrfs_path *path, u32 new_size, int from_end) { int slot; @@ -4136,7 +4594,7 @@ void btrfs_truncate_item(struct btrfs_trans_handle *trans, /* first correct the data pointers */ for (i = slot; i < nritems; i++) { u32 ioff; - item = btrfs_item_nr(leaf, i); + item = btrfs_item_nr(i); ioff = btrfs_token_item_offset(leaf, item, &token); btrfs_set_token_item_offset(leaf, item, @@ -4181,10 +4639,10 @@ void btrfs_truncate_item(struct btrfs_trans_handle *trans, btrfs_set_disk_key_offset(&disk_key, offset + size_diff); btrfs_set_item_key(leaf, &disk_key, slot); if (slot == 0) - fixup_low_keys(trans, root, path, &disk_key, 1); + fixup_low_keys(root, path, &disk_key, 1); } - item = btrfs_item_nr(leaf, slot); + item = btrfs_item_nr(slot); btrfs_set_item_size(leaf, item, new_size); btrfs_mark_buffer_dirty(leaf); @@ -4195,10 +4653,9 @@ void btrfs_truncate_item(struct btrfs_trans_handle *trans, } /* - * make the item pointed to by the path bigger, data_size is the new size. + * make the item pointed to by the path bigger, data_size is the added size. */ -void btrfs_extend_item(struct btrfs_trans_handle *trans, - struct btrfs_root *root, struct btrfs_path *path, +void btrfs_extend_item(struct btrfs_root *root, struct btrfs_path *path, u32 data_size) { int slot; @@ -4228,7 +4685,7 @@ void btrfs_extend_item(struct btrfs_trans_handle *trans, BUG_ON(slot < 0); if (slot >= nritems) { btrfs_print_leaf(root, leaf); - printk(KERN_CRIT "slot %d too large, nritems %d\n", + btrfs_crit(root->fs_info, "slot %d too large, nritems %d", slot, nritems); BUG_ON(1); } @@ -4239,7 +4696,7 @@ void btrfs_extend_item(struct btrfs_trans_handle *trans, /* first correct the data pointers */ for (i = slot; i < nritems; i++) { u32 ioff; - item = btrfs_item_nr(leaf, i); + item = btrfs_item_nr(i); ioff = btrfs_token_item_offset(leaf, item, &token); btrfs_set_token_item_offset(leaf, item, @@ -4253,7 +4710,7 @@ void btrfs_extend_item(struct btrfs_trans_handle *trans, data_end = old_data; old_size = btrfs_item_size_nr(leaf, slot); - item = btrfs_item_nr(leaf, slot); + item = btrfs_item_nr(slot); btrfs_set_item_size(leaf, item, old_size + data_size); btrfs_mark_buffer_dirty(leaf); @@ -4264,155 +4721,11 @@ void btrfs_extend_item(struct btrfs_trans_handle *trans, } /* - * Given a key and some data, insert items into the tree. - * This does all the path init required, making room in the tree if needed. - * Returns the number of keys that were inserted. - */ -int btrfs_insert_some_items(struct btrfs_trans_handle *trans, - struct btrfs_root *root, - struct btrfs_path *path, - struct btrfs_key *cpu_key, u32 *data_size, - int nr) -{ - struct extent_buffer *leaf; - struct btrfs_item *item; - int ret = 0; - int slot; - int i; - u32 nritems; - u32 total_data = 0; - u32 total_size = 0; - unsigned int data_end; - struct btrfs_disk_key disk_key; - struct btrfs_key found_key; - struct btrfs_map_token token; - - btrfs_init_map_token(&token); - - for (i = 0; i < nr; i++) { - if (total_size + data_size[i] + sizeof(struct btrfs_item) > - BTRFS_LEAF_DATA_SIZE(root)) { - break; - nr = i; - } - total_data += data_size[i]; - total_size += data_size[i] + sizeof(struct btrfs_item); - } - BUG_ON(nr == 0); - - ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); - if (ret == 0) - return -EEXIST; - if (ret < 0) - goto out; - - leaf = path->nodes[0]; - - nritems = btrfs_header_nritems(leaf); - data_end = leaf_data_end(root, leaf); - - if (btrfs_leaf_free_space(root, leaf) < total_size) { - for (i = nr; i >= 0; i--) { - total_data -= data_size[i]; - total_size -= data_size[i] + sizeof(struct btrfs_item); - if (total_size < btrfs_leaf_free_space(root, leaf)) - break; - } - nr = i; - } - - slot = path->slots[0]; - BUG_ON(slot < 0); - - if (slot != nritems) { - unsigned int old_data = btrfs_item_end_nr(leaf, slot); - - item = btrfs_item_nr(leaf, slot); - btrfs_item_key_to_cpu(leaf, &found_key, slot); - - /* figure out how many keys we can insert in here */ - total_data = data_size[0]; - for (i = 1; i < nr; i++) { - if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0) - break; - total_data += data_size[i]; - } - nr = i; - - if (old_data < data_end) { - btrfs_print_leaf(root, leaf); - printk(KERN_CRIT "slot %d old_data %d data_end %d\n", - slot, old_data, data_end); - BUG_ON(1); - } - /* - * item0..itemN ... dataN.offset..dataN.size .. data0.size - */ - /* first correct the data pointers */ - for (i = slot; i < nritems; i++) { - u32 ioff; - - item = btrfs_item_nr(leaf, i); - ioff = btrfs_token_item_offset(leaf, item, &token); - btrfs_set_token_item_offset(leaf, item, - ioff - total_data, &token); - } - /* shift the items */ - memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), - btrfs_item_nr_offset(slot), - (nritems - slot) * sizeof(struct btrfs_item)); - - /* shift the data */ - memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + - data_end - total_data, btrfs_leaf_data(leaf) + - data_end, old_data - data_end); - data_end = old_data; - } else { - /* - * this sucks but it has to be done, if we are inserting at - * the end of the leaf only insert 1 of the items, since we - * have no way of knowing whats on the next leaf and we'd have - * to drop our current locks to figure it out - */ - nr = 1; - } - - /* setup the item for the new data */ - for (i = 0; i < nr; i++) { - btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); - btrfs_set_item_key(leaf, &disk_key, slot + i); - item = btrfs_item_nr(leaf, slot + i); - btrfs_set_token_item_offset(leaf, item, - data_end - data_size[i], &token); - data_end -= data_size[i]; - btrfs_set_token_item_size(leaf, item, data_size[i], &token); - } - btrfs_set_header_nritems(leaf, nritems + nr); - btrfs_mark_buffer_dirty(leaf); - - ret = 0; - if (slot == 0) { - btrfs_cpu_key_to_disk(&disk_key, cpu_key); - fixup_low_keys(trans, root, path, &disk_key, 1); - } - - if (btrfs_leaf_free_space(root, leaf) < 0) { - btrfs_print_leaf(root, leaf); - BUG(); - } -out: - if (!ret) - ret = nr; - return ret; -} - -/* * this is a helper for btrfs_insert_empty_items, the main goal here is * to save stack depth by doing the bulk of the work in a function * that doesn't call btrfs_search_slot */ -void setup_items_for_insert(struct btrfs_trans_handle *trans, - struct btrfs_root *root, struct btrfs_path *path, +void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *cpu_key, u32 *data_size, u32 total_data, u32 total_size, int nr) { @@ -4435,7 +4748,7 @@ void setup_items_for_insert(struct btrfs_trans_handle *trans, if (btrfs_leaf_free_space(root, leaf) < total_size) { btrfs_print_leaf(root, leaf); - printk(KERN_CRIT "not enough freespace need %u have %d\n", + btrfs_crit(root->fs_info, "not enough freespace need %u have %d", total_size, btrfs_leaf_free_space(root, leaf)); BUG(); } @@ -4445,7 +4758,7 @@ void setup_items_for_insert(struct btrfs_trans_handle *trans, if (old_data < data_end) { btrfs_print_leaf(root, leaf); - printk(KERN_CRIT "slot %d old_data %d data_end %d\n", + btrfs_crit(root->fs_info, "slot %d old_data %d data_end %d", slot, old_data, data_end); BUG_ON(1); } @@ -4456,7 +4769,7 @@ void setup_items_for_insert(struct btrfs_trans_handle *trans, for (i = slot; i < nritems; i++) { u32 ioff; - item = btrfs_item_nr(leaf, i); + item = btrfs_item_nr( i); ioff = btrfs_token_item_offset(leaf, item, &token); btrfs_set_token_item_offset(leaf, item, ioff - total_data, &token); @@ -4477,7 +4790,7 @@ void setup_items_for_insert(struct btrfs_trans_handle *trans, for (i = 0; i < nr; i++) { btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); btrfs_set_item_key(leaf, &disk_key, slot + i); - item = btrfs_item_nr(leaf, slot + i); + item = btrfs_item_nr(slot + i); btrfs_set_token_item_offset(leaf, item, data_end - data_size[i], &token); data_end -= data_size[i]; @@ -4488,7 +4801,7 @@ void setup_items_for_insert(struct btrfs_trans_handle *trans, if (slot == 0) { btrfs_cpu_key_to_disk(&disk_key, cpu_key); - fixup_low_keys(trans, root, path, &disk_key, 1); + fixup_low_keys(root, path, &disk_key, 1); } btrfs_unlock_up_safe(path, 1); btrfs_mark_buffer_dirty(leaf); @@ -4528,7 +4841,7 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, slot = path->slots[0]; BUG_ON(slot < 0); - setup_items_for_insert(trans, root, path, cpu_key, data_size, + setup_items_for_insert(root, path, cpu_key, data_size, total_data, total_size, nr); return 0; } @@ -4566,9 +4879,8 @@ int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root * the tree should have been previously balanced so the deletion does not * empty a node. */ -static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, - struct btrfs_path *path, int level, int slot, - int tree_mod_log) +static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, + int level, int slot) { struct extent_buffer *parent = path->nodes[level]; u32 nritems; @@ -4576,7 +4888,7 @@ static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, nritems = btrfs_header_nritems(parent); if (slot != nritems - 1) { - if (tree_mod_log && level) + if (level) tree_mod_log_eb_move(root->fs_info, parent, slot, slot + 1, nritems - slot - 1); memmove_extent_buffer(parent, @@ -4584,9 +4896,9 @@ static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, btrfs_node_key_ptr_offset(slot + 1), sizeof(struct btrfs_key_ptr) * (nritems - slot - 1)); - } else if (tree_mod_log && level) { + } else if (level) { ret = tree_mod_log_insert_key(root->fs_info, parent, slot, - MOD_LOG_KEY_REMOVE); + MOD_LOG_KEY_REMOVE, GFP_NOFS); BUG_ON(ret < 0); } @@ -4600,7 +4912,7 @@ static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_disk_key disk_key; btrfs_node_key(parent, &disk_key, 0); - fixup_low_keys(trans, root, path, &disk_key, level + 1); + fixup_low_keys(root, path, &disk_key, level + 1); } btrfs_mark_buffer_dirty(parent); } @@ -4621,7 +4933,7 @@ static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, struct extent_buffer *leaf) { WARN_ON(btrfs_header_generation(leaf) != trans->transid); - del_ptr(trans, root, path, 1, path->slots[1], 1); + del_ptr(root, path, 1, path->slots[1]); /* * btrfs_free_extent is expensive, we want to make sure we @@ -4673,7 +4985,7 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, for (i = slot + nr; i < nritems; i++) { u32 ioff; - item = btrfs_item_nr(leaf, i); + item = btrfs_item_nr(i); ioff = btrfs_token_item_offset(leaf, item, &token); btrfs_set_token_item_offset(leaf, item, ioff + dsize, &token); @@ -4702,7 +5014,7 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_disk_key disk_key; btrfs_item_key(leaf, &disk_key, 0); - fixup_low_keys(trans, root, path, &disk_key, 1); + fixup_low_keys(root, path, &disk_key, 1); } /* delete the leaf if it is mostly empty */ @@ -4766,14 +5078,18 @@ int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) btrfs_item_key_to_cpu(path->nodes[0], &key, 0); - if (key.offset > 0) + if (key.offset > 0) { key.offset--; - else if (key.type > 0) + } else if (key.type > 0) { key.type--; - else if (key.objectid > 0) + key.offset = (u64)-1; + } else if (key.objectid > 0) { key.objectid--; - else + key.type = (u8)-1; + key.offset = (u64)-1; + } else { return 1; + } btrfs_release_path(path); ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); @@ -4781,15 +5097,25 @@ int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) return ret; btrfs_item_key(path->nodes[0], &found_key, 0); ret = comp_keys(&found_key, &key); - if (ret < 0) + /* + * We might have had an item with the previous key in the tree right + * before we released our path. And after we released our path, that + * item might have been pushed to the first slot (0) of the leaf we + * were holding due to a tree balance. Alternatively, an item with the + * previous key can exist as the only element of a leaf (big fat item). + * Therefore account for these 2 cases, so that our callers (like + * btrfs_previous_item) don't miss an existing item with a key matching + * the previous key we computed above. + */ + if (ret <= 0) return 0; return 1; } /* * A helper function to walk down the tree starting at min_key, and looking - * for nodes or leaves that are either in cache or have a minimum - * transaction id. This is used by the btree defrag code, and tree logging + * for nodes or leaves that are have a minimum transaction id. + * This is used by the btree defrag code, and tree logging * * This does not cow, but it does stuff the starting key it finds back * into min_key, so you can call btrfs_search_slot with cow=1 on the @@ -4809,8 +5135,7 @@ int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) * was nothing in the tree that matched the search criteria. */ int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, - struct btrfs_key *max_key, - struct btrfs_path *path, int cache_only, + struct btrfs_path *path, u64 min_trans) { struct extent_buffer *cur; @@ -4850,43 +5175,18 @@ again: if (sret && slot > 0) slot--; /* - * check this node pointer against the cache_only and - * min_trans parameters. If it isn't in cache or is too - * old, skip to the next one. + * check this node pointer against the min_trans parameters. + * If it is too old, old, skip to the next one. */ while (slot < nritems) { - u64 blockptr; u64 gen; - struct extent_buffer *tmp; - struct btrfs_disk_key disk_key; - blockptr = btrfs_node_blockptr(cur, slot); gen = btrfs_node_ptr_generation(cur, slot); if (gen < min_trans) { slot++; continue; } - if (!cache_only) - break; - - if (max_key) { - btrfs_node_key(cur, &disk_key, slot); - if (comp_keys(&disk_key, max_key) >= 0) { - ret = 1; - goto out; - } - } - - tmp = btrfs_find_tree_block(root, blockptr, - btrfs_level_size(root, level - 1)); - - if (tmp && btrfs_buffer_uptodate(tmp, gen, 1) > 0) { - free_extent_buffer(tmp); - break; - } - if (tmp) - free_extent_buffer(tmp); - slot++; + break; } find_next_key: /* @@ -4897,7 +5197,7 @@ find_next_key: path->slots[level] = slot; btrfs_set_path_blocking(path); sret = btrfs_find_next_key(root, path, min_key, level, - cache_only, min_trans); + min_trans); if (sret == 0) { btrfs_release_path(path); goto again; @@ -4931,11 +5231,362 @@ out: return ret; } +static void tree_move_down(struct btrfs_root *root, + struct btrfs_path *path, + int *level, int root_level) +{ + BUG_ON(*level == 0); + path->nodes[*level - 1] = read_node_slot(root, path->nodes[*level], + path->slots[*level]); + path->slots[*level - 1] = 0; + (*level)--; +} + +static int tree_move_next_or_upnext(struct btrfs_root *root, + struct btrfs_path *path, + int *level, int root_level) +{ + int ret = 0; + int nritems; + nritems = btrfs_header_nritems(path->nodes[*level]); + + path->slots[*level]++; + + while (path->slots[*level] >= nritems) { + if (*level == root_level) + return -1; + + /* move upnext */ + path->slots[*level] = 0; + free_extent_buffer(path->nodes[*level]); + path->nodes[*level] = NULL; + (*level)++; + path->slots[*level]++; + + nritems = btrfs_header_nritems(path->nodes[*level]); + ret = 1; + } + return ret; +} + +/* + * Returns 1 if it had to move up and next. 0 is returned if it moved only next + * or down. + */ +static int tree_advance(struct btrfs_root *root, + struct btrfs_path *path, + int *level, int root_level, + int allow_down, + struct btrfs_key *key) +{ + int ret; + + if (*level == 0 || !allow_down) { + ret = tree_move_next_or_upnext(root, path, level, root_level); + } else { + tree_move_down(root, path, level, root_level); + ret = 0; + } + if (ret >= 0) { + if (*level == 0) + btrfs_item_key_to_cpu(path->nodes[*level], key, + path->slots[*level]); + else + btrfs_node_key_to_cpu(path->nodes[*level], key, + path->slots[*level]); + } + return ret; +} + +static int tree_compare_item(struct btrfs_root *left_root, + struct btrfs_path *left_path, + struct btrfs_path *right_path, + char *tmp_buf) +{ + int cmp; + int len1, len2; + unsigned long off1, off2; + + len1 = btrfs_item_size_nr(left_path->nodes[0], left_path->slots[0]); + len2 = btrfs_item_size_nr(right_path->nodes[0], right_path->slots[0]); + if (len1 != len2) + return 1; + + off1 = btrfs_item_ptr_offset(left_path->nodes[0], left_path->slots[0]); + off2 = btrfs_item_ptr_offset(right_path->nodes[0], + right_path->slots[0]); + + read_extent_buffer(left_path->nodes[0], tmp_buf, off1, len1); + + cmp = memcmp_extent_buffer(right_path->nodes[0], tmp_buf, off2, len1); + if (cmp) + return 1; + return 0; +} + +#define ADVANCE 1 +#define ADVANCE_ONLY_NEXT -1 + +/* + * This function compares two trees and calls the provided callback for + * every changed/new/deleted item it finds. + * If shared tree blocks are encountered, whole subtrees are skipped, making + * the compare pretty fast on snapshotted subvolumes. + * + * This currently works on commit roots only. As commit roots are read only, + * we don't do any locking. The commit roots are protected with transactions. + * Transactions are ended and rejoined when a commit is tried in between. + * + * This function checks for modifications done to the trees while comparing. + * If it detects a change, it aborts immediately. + */ +int btrfs_compare_trees(struct btrfs_root *left_root, + struct btrfs_root *right_root, + btrfs_changed_cb_t changed_cb, void *ctx) +{ + int ret; + int cmp; + struct btrfs_path *left_path = NULL; + struct btrfs_path *right_path = NULL; + struct btrfs_key left_key; + struct btrfs_key right_key; + char *tmp_buf = NULL; + int left_root_level; + int right_root_level; + int left_level; + int right_level; + int left_end_reached; + int right_end_reached; + int advance_left; + int advance_right; + u64 left_blockptr; + u64 right_blockptr; + u64 left_gen; + u64 right_gen; + + left_path = btrfs_alloc_path(); + if (!left_path) { + ret = -ENOMEM; + goto out; + } + right_path = btrfs_alloc_path(); + if (!right_path) { + ret = -ENOMEM; + goto out; + } + + tmp_buf = kmalloc(left_root->leafsize, GFP_NOFS); + if (!tmp_buf) { + ret = -ENOMEM; + goto out; + } + + left_path->search_commit_root = 1; + left_path->skip_locking = 1; + right_path->search_commit_root = 1; + right_path->skip_locking = 1; + + /* + * Strategy: Go to the first items of both trees. Then do + * + * If both trees are at level 0 + * Compare keys of current items + * If left < right treat left item as new, advance left tree + * and repeat + * If left > right treat right item as deleted, advance right tree + * and repeat + * If left == right do deep compare of items, treat as changed if + * needed, advance both trees and repeat + * If both trees are at the same level but not at level 0 + * Compare keys of current nodes/leafs + * If left < right advance left tree and repeat + * If left > right advance right tree and repeat + * If left == right compare blockptrs of the next nodes/leafs + * If they match advance both trees but stay at the same level + * and repeat + * If they don't match advance both trees while allowing to go + * deeper and repeat + * If tree levels are different + * Advance the tree that needs it and repeat + * + * Advancing a tree means: + * If we are at level 0, try to go to the next slot. If that's not + * possible, go one level up and repeat. Stop when we found a level + * where we could go to the next slot. We may at this point be on a + * node or a leaf. + * + * If we are not at level 0 and not on shared tree blocks, go one + * level deeper. + * + * If we are not at level 0 and on shared tree blocks, go one slot to + * the right if possible or go up and right. + */ + + down_read(&left_root->fs_info->commit_root_sem); + left_level = btrfs_header_level(left_root->commit_root); + left_root_level = left_level; + left_path->nodes[left_level] = left_root->commit_root; + extent_buffer_get(left_path->nodes[left_level]); + + right_level = btrfs_header_level(right_root->commit_root); + right_root_level = right_level; + right_path->nodes[right_level] = right_root->commit_root; + extent_buffer_get(right_path->nodes[right_level]); + up_read(&left_root->fs_info->commit_root_sem); + + if (left_level == 0) + btrfs_item_key_to_cpu(left_path->nodes[left_level], + &left_key, left_path->slots[left_level]); + else + btrfs_node_key_to_cpu(left_path->nodes[left_level], + &left_key, left_path->slots[left_level]); + if (right_level == 0) + btrfs_item_key_to_cpu(right_path->nodes[right_level], + &right_key, right_path->slots[right_level]); + else + btrfs_node_key_to_cpu(right_path->nodes[right_level], + &right_key, right_path->slots[right_level]); + + left_end_reached = right_end_reached = 0; + advance_left = advance_right = 0; + + while (1) { + if (advance_left && !left_end_reached) { + ret = tree_advance(left_root, left_path, &left_level, + left_root_level, + advance_left != ADVANCE_ONLY_NEXT, + &left_key); + if (ret < 0) + left_end_reached = ADVANCE; + advance_left = 0; + } + if (advance_right && !right_end_reached) { + ret = tree_advance(right_root, right_path, &right_level, + right_root_level, + advance_right != ADVANCE_ONLY_NEXT, + &right_key); + if (ret < 0) + right_end_reached = ADVANCE; + advance_right = 0; + } + + if (left_end_reached && right_end_reached) { + ret = 0; + goto out; + } else if (left_end_reached) { + if (right_level == 0) { + ret = changed_cb(left_root, right_root, + left_path, right_path, + &right_key, + BTRFS_COMPARE_TREE_DELETED, + ctx); + if (ret < 0) + goto out; + } + advance_right = ADVANCE; + continue; + } else if (right_end_reached) { + if (left_level == 0) { + ret = changed_cb(left_root, right_root, + left_path, right_path, + &left_key, + BTRFS_COMPARE_TREE_NEW, + ctx); + if (ret < 0) + goto out; + } + advance_left = ADVANCE; + continue; + } + + if (left_level == 0 && right_level == 0) { + cmp = btrfs_comp_cpu_keys(&left_key, &right_key); + if (cmp < 0) { + ret = changed_cb(left_root, right_root, + left_path, right_path, + &left_key, + BTRFS_COMPARE_TREE_NEW, + ctx); + if (ret < 0) + goto out; + advance_left = ADVANCE; + } else if (cmp > 0) { + ret = changed_cb(left_root, right_root, + left_path, right_path, + &right_key, + BTRFS_COMPARE_TREE_DELETED, + ctx); + if (ret < 0) + goto out; + advance_right = ADVANCE; + } else { + enum btrfs_compare_tree_result cmp; + + WARN_ON(!extent_buffer_uptodate(left_path->nodes[0])); + ret = tree_compare_item(left_root, left_path, + right_path, tmp_buf); + if (ret) + cmp = BTRFS_COMPARE_TREE_CHANGED; + else + cmp = BTRFS_COMPARE_TREE_SAME; + ret = changed_cb(left_root, right_root, + left_path, right_path, + &left_key, cmp, ctx); + if (ret < 0) + goto out; + advance_left = ADVANCE; + advance_right = ADVANCE; + } + } else if (left_level == right_level) { + cmp = btrfs_comp_cpu_keys(&left_key, &right_key); + if (cmp < 0) { + advance_left = ADVANCE; + } else if (cmp > 0) { + advance_right = ADVANCE; + } else { + left_blockptr = btrfs_node_blockptr( + left_path->nodes[left_level], + left_path->slots[left_level]); + right_blockptr = btrfs_node_blockptr( + right_path->nodes[right_level], + right_path->slots[right_level]); + left_gen = btrfs_node_ptr_generation( + left_path->nodes[left_level], + left_path->slots[left_level]); + right_gen = btrfs_node_ptr_generation( + right_path->nodes[right_level], + right_path->slots[right_level]); + if (left_blockptr == right_blockptr && + left_gen == right_gen) { + /* + * As we're on a shared block, don't + * allow to go deeper. + */ + advance_left = ADVANCE_ONLY_NEXT; + advance_right = ADVANCE_ONLY_NEXT; + } else { + advance_left = ADVANCE; + advance_right = ADVANCE; + } + } + } else if (left_level < right_level) { + advance_right = ADVANCE; + } else { + advance_left = ADVANCE; + } + } + +out: + btrfs_free_path(left_path); + btrfs_free_path(right_path); + kfree(tmp_buf); + return ret; +} + /* * this is similar to btrfs_next_leaf, but does not try to preserve * and fixup the path. It looks for and returns the next key in the - * tree based on the current path and the cache_only and min_trans - * parameters. + * tree based on the current path and the min_trans parameters. * * 0 is returned if another key is found, < 0 if there are any errors * and 1 is returned if there are no higher keys in the tree @@ -4944,8 +5595,7 @@ out: * calling this function. */ int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, - struct btrfs_key *key, int level, - int cache_only, u64 min_trans) + struct btrfs_key *key, int level, u64 min_trans) { int slot; struct extent_buffer *c; @@ -4996,22 +5646,8 @@ next: if (level == 0) btrfs_item_key_to_cpu(c, key, slot); else { - u64 blockptr = btrfs_node_blockptr(c, slot); u64 gen = btrfs_node_ptr_generation(c, slot); - if (cache_only) { - struct extent_buffer *cur; - cur = btrfs_find_tree_block(root, blockptr, - btrfs_level_size(root, level - 1)); - if (!cur || - btrfs_buffer_uptodate(cur, gen, 1) <= 0) { - slot++; - if (cur) - free_extent_buffer(cur); - goto next; - } - free_extent_buffer(cur); - } if (gen < min_trans) { slot++; goto next; @@ -5082,6 +5718,24 @@ again: ret = 0; goto done; } + /* + * So the above check misses one case: + * - after releasing the path above, someone has removed the item that + * used to be at the very end of the block, and balance between leafs + * gets another one with bigger key.offset to replace it. + * + * This one should be returned as well, or we can get leaf corruption + * later(esp. in __btrfs_drop_extents()). + * + * And a bit more explanation about this check, + * with ret > 0, the key isn't found, the path points to the slot + * where it should be inserted, so the path->slots[0] item must be the + * bigger one. + */ + if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) { + ret = 0; + goto done; + } while (level < BTRFS_MAX_LEVEL) { if (!path->nodes[level]) { @@ -5127,6 +5781,7 @@ again: * locked. To solve this situation, we give up * on our lock and cycle. */ + free_extent_buffer(next); btrfs_release_path(path); cond_resched(); goto again; @@ -5229,3 +5884,46 @@ int btrfs_previous_item(struct btrfs_root *root, } return 1; } + +/* + * search in extent tree to find a previous Metadata/Data extent item with + * min objecitd. + * + * returns 0 if something is found, 1 if nothing was found and < 0 on error + */ +int btrfs_previous_extent_item(struct btrfs_root *root, + struct btrfs_path *path, u64 min_objectid) +{ + struct btrfs_key found_key; + struct extent_buffer *leaf; + u32 nritems; + int ret; + + while (1) { + if (path->slots[0] == 0) { + btrfs_set_path_blocking(path); + ret = btrfs_prev_leaf(root, path); + if (ret != 0) + return ret; + } else { + path->slots[0]--; + } + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + if (nritems == 0) + return 1; + if (path->slots[0] == nritems) + path->slots[0]--; + + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + if (found_key.objectid < min_objectid) + break; + if (found_key.type == BTRFS_EXTENT_ITEM_KEY || + found_key.type == BTRFS_METADATA_ITEM_KEY) + return 0; + if (found_key.objectid == min_objectid && + found_key.type < BTRFS_EXTENT_ITEM_KEY) + break; + } + return 1; +} |