diff options
Diffstat (limited to 'fs/btrfs/ctree.c')
| -rw-r--r-- | fs/btrfs/ctree.c | 4899 |
1 files changed, 3324 insertions, 1575 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 37f31b5529a..aeab453b8e2 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -17,6 +17,8 @@ */ #include <linux/sched.h> +#include <linux/slab.h> +#include <linux/rbtree.h> #include "ctree.h" #include "disk-io.h" #include "transaction.h" @@ -35,15 +37,15 @@ 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 int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, - struct btrfs_path *path, int level, int slot); +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 btrfs_path *btrfs_alloc_path(void) { struct btrfs_path *path; path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); - if (path) - path->reada = 1; return path; } @@ -55,8 +57,13 @@ noinline void btrfs_set_path_blocking(struct btrfs_path *p) { int i; for (i = 0; i < BTRFS_MAX_LEVEL; i++) { - if (p->nodes[i] && p->locks[i]) - btrfs_set_lock_blocking(p->nodes[i]); + if (!p->nodes[i] || !p->locks[i]) + continue; + btrfs_set_lock_blocking_rw(p->nodes[i], p->locks[i]); + if (p->locks[i] == BTRFS_READ_LOCK) + p->locks[i] = BTRFS_READ_LOCK_BLOCKING; + else if (p->locks[i] == BTRFS_WRITE_LOCK) + p->locks[i] = BTRFS_WRITE_LOCK_BLOCKING; } } @@ -69,7 +76,7 @@ noinline void btrfs_set_path_blocking(struct btrfs_path *p) * for held */ noinline void btrfs_clear_path_blocking(struct btrfs_path *p, - struct extent_buffer *held) + struct extent_buffer *held, int held_rw) { int i; @@ -80,26 +87,38 @@ noinline void btrfs_clear_path_blocking(struct btrfs_path *p, * really sure by forcing the path to blocking before we clear * the path blocking. */ - if (held) - btrfs_set_lock_blocking(held); + if (held) { + btrfs_set_lock_blocking_rw(held, held_rw); + if (held_rw == BTRFS_WRITE_LOCK) + held_rw = BTRFS_WRITE_LOCK_BLOCKING; + else if (held_rw == BTRFS_READ_LOCK) + held_rw = BTRFS_READ_LOCK_BLOCKING; + } btrfs_set_path_blocking(p); #endif for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) { - if (p->nodes[i] && p->locks[i]) - btrfs_clear_lock_blocking(p->nodes[i]); + if (p->nodes[i] && p->locks[i]) { + btrfs_clear_lock_blocking_rw(p->nodes[i], p->locks[i]); + if (p->locks[i] == BTRFS_WRITE_LOCK_BLOCKING) + p->locks[i] = BTRFS_WRITE_LOCK; + else if (p->locks[i] == BTRFS_READ_LOCK_BLOCKING) + p->locks[i] = BTRFS_READ_LOCK; + } } #ifdef CONFIG_DEBUG_LOCK_ALLOC if (held) - btrfs_clear_lock_blocking(held); + btrfs_clear_lock_blocking_rw(held, held_rw); #endif } /* this also releases the path */ void btrfs_free_path(struct btrfs_path *p) { - btrfs_release_path(NULL, p); + if (!p) + return; + btrfs_release_path(p); kmem_cache_free(btrfs_path_cachep, p); } @@ -109,7 +128,7 @@ void btrfs_free_path(struct btrfs_path *p) * * It is safe to call this on paths that no locks or extent buffers held. */ -noinline void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) +noinline void btrfs_release_path(struct btrfs_path *p) { int i; @@ -118,7 +137,7 @@ noinline void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) if (!p->nodes[i]) continue; if (p->locks[i]) { - btrfs_tree_unlock(p->nodes[i]); + btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); p->locks[i] = 0; } free_extent_buffer(p->nodes[i]); @@ -139,10 +158,24 @@ noinline void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) struct extent_buffer *btrfs_root_node(struct btrfs_root *root) { struct extent_buffer *eb; - spin_lock(&root->node_lock); - eb = root->node; - extent_buffer_get(eb); - spin_unlock(&root->node_lock); + + while (1) { + rcu_read_lock(); + eb = rcu_dereference(root->node); + + /* + * RCU really hurts here, we could free up the root node because + * it was cow'ed but we may not get the new root node yet so do + * the inc_not_zero dance and if it doesn't work then + * synchronize_rcu and try again. + */ + if (atomic_inc_not_zero(&eb->refs)) { + rcu_read_unlock(); + break; + } + rcu_read_unlock(); + synchronize_rcu(); + } return eb; } @@ -157,30 +190,46 @@ struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) while (1) { eb = btrfs_root_node(root); btrfs_tree_lock(eb); - - spin_lock(&root->node_lock); - if (eb == root->node) { - spin_unlock(&root->node_lock); + if (eb == root->node) break; - } - spin_unlock(&root->node_lock); - btrfs_tree_unlock(eb); free_extent_buffer(eb); } return eb; } +/* loop around taking references on and locking the root node of the + * tree until you end up with a lock on the root. A locked buffer + * is returned, with a reference held. + */ +static struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root) +{ + struct extent_buffer *eb; + + while (1) { + eb = btrfs_root_node(root); + btrfs_tree_read_lock(eb); + if (eb == root->node) + break; + btrfs_tree_read_unlock(eb); + free_extent_buffer(eb); + } + return eb; +} + /* cowonly root (everything not a reference counted cow subvolume), just get * put onto a simple dirty list. transaction.c walks this to make sure they * get properly updated on disk. */ static void add_root_to_dirty_list(struct btrfs_root *root) { - if (root->track_dirty && list_empty(&root->dirty_list)) { + spin_lock(&root->fs_info->trans_lock); + 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); } + spin_unlock(&root->fs_info->trans_lock); } /* @@ -194,46 +243,46 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans, struct extent_buffer **cow_ret, u64 new_root_objectid) { struct extent_buffer *cow; - u32 nritems; int ret = 0; int level; - struct btrfs_root *new_root; - - new_root = kmalloc(sizeof(*new_root), GFP_NOFS); - if (!new_root) - return -ENOMEM; - - memcpy(new_root, root, sizeof(*new_root)); - new_root->root_key.objectid = new_root_objectid; + 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); - nritems = btrfs_header_nritems(buf); + if (level == 0) + btrfs_item_key(buf, &disk_key, 0); + else + btrfs_node_key(buf, &disk_key, 0); - cow = btrfs_alloc_free_block(trans, new_root, buf->len, 0, - new_root_objectid, trans->transid, - level, buf->start, 0); - if (IS_ERR(cow)) { - kfree(new_root); + cow = btrfs_alloc_free_block(trans, root, buf->len, 0, + new_root_objectid, &disk_key, level, + buf->start, 0); + if (IS_ERR(cow)) return PTR_ERR(cow); - } copy_extent_buffer(cow, buf, 0, 0, cow->len); btrfs_set_header_bytenr(cow, cow->start); btrfs_set_header_generation(cow, trans->transid); - btrfs_set_header_owner(cow, new_root_objectid); - btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN); + btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); + btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | + BTRFS_HEADER_FLAG_RELOC); + if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) + btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); + 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); - ret = btrfs_inc_ref(trans, new_root, buf, cow, NULL); - kfree(new_root); + if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) + ret = btrfs_inc_ref(trans, root, cow, 1, 1); + else + ret = btrfs_inc_ref(trans, root, cow, 0, 1); if (ret) return ret; @@ -243,6 +292,796 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans, return 0; } +enum mod_log_op { + MOD_LOG_KEY_REPLACE, + MOD_LOG_KEY_ADD, + MOD_LOG_KEY_REMOVE, + MOD_LOG_KEY_REMOVE_WHILE_FREEING, + MOD_LOG_KEY_REMOVE_WHILE_MOVING, + MOD_LOG_MOVE_KEYS, + MOD_LOG_ROOT_REPLACE, +}; + +struct tree_mod_move { + int dst_slot; + int nr_items; +}; + +struct tree_mod_root { + u64 logical; + u8 level; +}; + +struct tree_mod_elem { + struct rb_node node; + u64 index; /* shifted logical */ + u64 seq; + enum mod_log_op op; + + /* this is used for MOD_LOG_KEY_* and MOD_LOG_MOVE_KEYS operations */ + int slot; + + /* this is used for MOD_LOG_KEY* and MOD_LOG_ROOT_REPLACE */ + u64 generation; + + /* those are used for op == MOD_LOG_KEY_{REPLACE,REMOVE} */ + struct btrfs_disk_key key; + u64 blockptr; + + /* this is used for op == MOD_LOG_MOVE_KEYS */ + struct tree_mod_move move; + + /* this is used for op == MOD_LOG_ROOT_REPLACE */ + struct tree_mod_root old_root; +}; + +static inline void tree_mod_log_read_lock(struct btrfs_fs_info *fs_info) +{ + read_lock(&fs_info->tree_mod_log_lock); +} + +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) +{ + 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); + 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, + struct seq_list *elem) +{ + struct rb_root *tm_root; + struct rb_node *node; + struct rb_node *next; + struct seq_list *cur_elem; + struct tree_mod_elem *tm; + u64 min_seq = (u64)-1; + u64 seq_putting = elem->seq; + + if (!seq_putting) + return; + + 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->seq < min_seq) { + if (seq_putting > cur_elem->seq) { + /* + * blocker with lower sequence number exists, we + * cannot remove anything from the log + */ + 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. + */ + 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->seq > min_seq) + continue; + rb_erase(node, tm_root); + kfree(tm); + } + tree_mod_log_write_unlock(fs_info); +} + +/* + * key order of the log: + * index -> sequence + * + * 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) +{ + struct rb_root *tm_root; + struct rb_node **new; + struct rb_node *parent = NULL; + struct tree_mod_elem *cur; + + BUG_ON(!tm); + + tm->seq = btrfs_inc_tree_mod_seq(fs_info); + + tm_root = &fs_info->tree_mod_log; + new = &tm_root->rb_node; + while (*new) { + cur = container_of(*new, struct tree_mod_elem, node); + parent = *new; + if (cur->index < tm->index) + new = &((*new)->rb_left); + else if (cur->index > tm->index) + new = &((*new)->rb_right); + else if (cur->seq < tm->seq) + new = &((*new)->rb_left); + else if (cur->seq > tm->seq) + new = &((*new)->rb_right); + else + return -EEXIST; + } + + rb_link_node(&tm->node, parent, new); + rb_insert_color(&tm->node, tm_root); + 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 && 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; +} + +/* 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) +{ + smp_mb(); + if (list_empty(&(fs_info)->tree_mod_seq_list)) + return 0; + if (eb && btrfs_header_level(eb) == 0) + return 0; + + return 1; +} + +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; + + tm = kzalloc(sizeof(*tm), flags); + if (!tm) + return NULL; + + tm->index = eb->start >> PAGE_CACHE_SHIFT; + if (op != MOD_LOG_KEY_ADD) { + btrfs_node_key(eb, &tm->key, slot); + tm->blockptr = btrfs_node_blockptr(eb, slot); + } + tm->op = op; + tm->slot = slot; + tm->generation = btrfs_node_ptr_generation(eb, slot); + RB_CLEAR_NODE(&tm->node); + + 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, gfp_t flags) +{ + 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 +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 = NULL; + struct tree_mod_elem **tm_list = NULL; + int ret = 0; + int i; + int locked = 0; + + if (!tree_mod_need_log(fs_info, eb)) + return 0; + + tm_list = kzalloc(nr_items * sizeof(struct tree_mod_elem *), flags); + if (!tm_list) + return -ENOMEM; + + tm = kzalloc(sizeof(*tm), flags); + if (!tm) { + ret = -ENOMEM; + goto free_tms; + } + + tm->index = eb->start >> PAGE_CACHE_SHIFT; + tm->slot = src_slot; + tm->move.dst_slot = dst_slot; + 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); + 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, + int log_removal) +{ + struct tree_mod_elem *tm = NULL; + struct tree_mod_elem **tm_list = NULL; + int nritems = 0; + int ret = 0; + int i; + + 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; + tm->old_root.level = btrfs_header_level(old_root); + tm->generation = btrfs_header_generation(old_root); + tm->op = MOD_LOG_ROOT_REPLACE; + + 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; +} + +static struct tree_mod_elem * +__tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq, + int smallest) +{ + struct rb_root *tm_root; + struct rb_node *node; + struct tree_mod_elem *cur = NULL; + struct tree_mod_elem *found = NULL; + u64 index = start >> PAGE_CACHE_SHIFT; + + tree_mod_log_read_lock(fs_info); + tm_root = &fs_info->tree_mod_log; + node = tm_root->rb_node; + while (node) { + cur = container_of(node, struct tree_mod_elem, node); + if (cur->index < index) { + node = node->rb_left; + } else if (cur->index > index) { + node = node->rb_right; + } 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->seq > cur->seq); + found = cur; + node = node->rb_left; + } else if (cur->seq > min_seq) { + /* we want the node with the smallest seq */ + if (found) + BUG_ON(found->seq < cur->seq); + found = cur; + node = node->rb_right; + } else { + found = cur; + break; + } + } + tree_mod_log_read_unlock(fs_info); + + return found; +} + +/* + * this returns the element from the log with the smallest time sequence + * value that's in the log (the oldest log item). any element with a time + * sequence lower than min_seq will be ignored. + */ +static struct tree_mod_elem * +tree_mod_log_search_oldest(struct btrfs_fs_info *fs_info, u64 start, + u64 min_seq) +{ + return __tree_mod_log_search(fs_info, start, min_seq, 1); +} + +/* + * this returns the element from the log with the largest time sequence + * value that's in the log (the most recent log item). any element with + * a time sequence lower than min_seq will be ignored. + */ +static struct tree_mod_elem * +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 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 = 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_need_log(fs_info, NULL)) + return 0; + + if (btrfs_header_level(dst) == 0 && btrfs_header_level(src) == 0) + return 0; + + tm_list = kzalloc(nr_items * 2 * sizeof(struct tree_mod_elem *), + GFP_NOFS); + if (!tm_list) + return -ENOMEM; + + tm_list_add = tm_list; + tm_list_rem = tm_list + nr_items; + for (i = 0; i < nr_items; i++) { + 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 +tree_mod_log_eb_move(struct btrfs_fs_info *fs_info, struct extent_buffer *dst, + int dst_offset, int src_offset, int nr_items) +{ + int ret; + ret = tree_mod_log_insert_move(fs_info, dst, dst_offset, src_offset, + nr_items, GFP_NOFS); + BUG_ON(ret < 0); +} + +static noinline void +tree_mod_log_set_node_key(struct btrfs_fs_info *fs_info, + struct extent_buffer *eb, int slot, int atomic) +{ + int ret; + + ret = tree_mod_log_insert_key(fs_info, eb, slot, + MOD_LOG_KEY_REPLACE, + atomic ? GFP_ATOMIC : GFP_NOFS); + BUG_ON(ret < 0); +} + +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 = 0; + + if (btrfs_header_level(eb) == 0) + return 0; + + if (!tree_mod_need_log(fs_info, NULL)) + return 0; + + nritems = btrfs_header_nritems(eb); + 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 noinline void +tree_mod_log_set_root_pointer(struct btrfs_root *root, + struct extent_buffer *new_root_node, + int log_removal) +{ + int ret; + ret = tree_mod_log_insert_root(root->fs_info, root->node, + new_root_node, GFP_NOFS, log_removal); + BUG_ON(ret < 0); +} + +/* + * check if the tree block can be shared by multiple trees + */ +int btrfs_block_can_be_shared(struct btrfs_root *root, + struct extent_buffer *buf) +{ + /* + * Tree blocks not in refernece counted trees and tree roots + * are never shared. If a block was allocated after the last + * snapshot and the block was not allocated by tree relocation, + * we know the block is not shared. + */ + 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 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) && + btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) + return 1; +#endif + return 0; +} + +static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_buffer *buf, + struct extent_buffer *cow, + int *last_ref) +{ + u64 refs; + u64 owner; + u64 flags; + u64 new_flags = 0; + int ret; + + /* + * Backrefs update rules: + * + * Always use full backrefs for extent pointers in tree block + * allocated by tree relocation. + * + * If a shared tree block is no longer referenced by its owner + * tree (btrfs_header_owner(buf) == root->root_key.objectid), + * use full backrefs for extent pointers in tree block. + * + * If a tree block is been relocating + * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), + * use full backrefs for extent pointers in tree block. + * The reason for this is some operations (such as drop tree) + * are only allowed for blocks use full backrefs. + */ + + if (btrfs_block_can_be_shared(root, buf)) { + ret = btrfs_lookup_extent_info(trans, root, buf->start, + btrfs_header_level(buf), 1, + &refs, &flags); + if (ret) + return ret; + if (refs == 0) { + ret = -EROFS; + btrfs_std_error(root->fs_info, ret); + return ret; + } + } else { + refs = 1; + if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || + btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) + flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; + else + flags = 0; + } + + owner = btrfs_header_owner(buf); + BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && + !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); + + if (refs > 1) { + if ((owner == root->root_key.objectid || + root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && + !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { + ret = btrfs_inc_ref(trans, root, buf, 1, 1); + BUG_ON(ret); /* -ENOMEM */ + + if (root->root_key.objectid == + BTRFS_TREE_RELOC_OBJECTID) { + ret = btrfs_dec_ref(trans, root, buf, 0, 1); + BUG_ON(ret); /* -ENOMEM */ + ret = btrfs_inc_ref(trans, root, cow, 1, 1); + BUG_ON(ret); /* -ENOMEM */ + } + new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; + } else { + + if (root->root_key.objectid == + BTRFS_TREE_RELOC_OBJECTID) + ret = btrfs_inc_ref(trans, root, cow, 1, 1); + else + ret = btrfs_inc_ref(trans, root, cow, 0, 1); + 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, level, 0); + if (ret) + return ret; + } + } else { + if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { + if (root->root_key.objectid == + BTRFS_TREE_RELOC_OBJECTID) + ret = btrfs_inc_ref(trans, root, cow, 1, 1); + else + ret = btrfs_inc_ref(trans, root, cow, 0, 1); + BUG_ON(ret); /* -ENOMEM */ + ret = btrfs_dec_ref(trans, root, buf, 1, 1); + BUG_ON(ret); /* -ENOMEM */ + } + clean_tree_block(trans, root, buf); + *last_ref = 1; + } + return 0; +} + /* * does the dirty work in cow of a single block. The parent block (if * supplied) is updated to point to the new cow copy. The new buffer is marked @@ -254,63 +1093,49 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans, * empty_size -- a hint that you plan on doing more cow. This is the size in * bytes the allocator should try to find free next to the block it returns. * This is just a hint and may be ignored by the allocator. - * - * prealloc_dest -- if you have already reserved a destination for the cow, - * this uses that block instead of allocating a new one. - * btrfs_alloc_reserved_extent is used to finish the allocation. */ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, struct extent_buffer *parent, int parent_slot, struct extent_buffer **cow_ret, - u64 search_start, u64 empty_size, - u64 prealloc_dest) + u64 search_start, u64 empty_size) { - u64 parent_start; + struct btrfs_disk_key disk_key; struct extent_buffer *cow; - u32 nritems; - int ret = 0; - int level; + int level, ret; + int last_ref = 0; int unlock_orig = 0; + u64 parent_start; if (*cow_ret == buf) unlock_orig = 1; btrfs_assert_tree_locked(buf); - if (parent) - parent_start = parent->start; - else - parent_start = 0; - - 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); - nritems = btrfs_header_nritems(buf); - if (prealloc_dest) { - struct btrfs_key ins; + if (level == 0) + btrfs_item_key(buf, &disk_key, 0); + else + btrfs_node_key(buf, &disk_key, 0); - ins.objectid = prealloc_dest; - ins.offset = buf->len; - ins.type = BTRFS_EXTENT_ITEM_KEY; + if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { + if (parent) + parent_start = parent->start; + else + parent_start = 0; + } else + parent_start = 0; - ret = btrfs_alloc_reserved_extent(trans, root, parent_start, - root->root_key.objectid, - trans->transid, level, &ins); - BUG_ON(ret); - cow = btrfs_init_new_buffer(trans, root, prealloc_dest, - buf->len, level); - } else { - cow = btrfs_alloc_free_block(trans, root, buf->len, - parent_start, - root->root_key.objectid, - trans->transid, level, - search_start, empty_size); - } + cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start, + root->root_key.objectid, &disk_key, + level, search_start, empty_size); if (IS_ERR(cow)) return PTR_ERR(cow); @@ -319,93 +1144,396 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, copy_extent_buffer(cow, buf, 0, 0, cow->len); btrfs_set_header_bytenr(cow, cow->start); btrfs_set_header_generation(cow, trans->transid); - btrfs_set_header_owner(cow, root->root_key.objectid); - btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN); + btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); + btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | + BTRFS_HEADER_FLAG_RELOC); + if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) + btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); + 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); - WARN_ON(btrfs_header_generation(buf) > trans->transid); - if (btrfs_header_generation(buf) != trans->transid) { - u32 nr_extents; - ret = btrfs_inc_ref(trans, root, buf, cow, &nr_extents); - if (ret) - return ret; + ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + return ret; + } - ret = btrfs_cache_ref(trans, root, buf, nr_extents); - WARN_ON(ret); - } else if (btrfs_header_owner(buf) == BTRFS_TREE_RELOC_OBJECTID) { - /* - * There are only two places that can drop reference to - * tree blocks owned by living reloc trees, one is here, - * the other place is btrfs_drop_subtree. In both places, - * we check reference count while tree block is locked. - * Furthermore, if reference count is one, it won't get - * increased by someone else. - */ - u32 refs; - ret = btrfs_lookup_extent_ref(trans, root, buf->start, - buf->len, &refs); - BUG_ON(ret); - if (refs == 1) { - ret = btrfs_update_ref(trans, root, buf, cow, - 0, nritems); - clean_tree_block(trans, root, buf); - } else { - ret = btrfs_inc_ref(trans, root, buf, cow, NULL); - } - BUG_ON(ret); - } else { - ret = btrfs_update_ref(trans, root, buf, cow, 0, nritems); + if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) { + ret = btrfs_reloc_cow_block(trans, root, buf, cow); if (ret) return ret; - clean_tree_block(trans, root, buf); - } - - if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { - ret = btrfs_reloc_tree_cache_ref(trans, root, cow, buf->start); - WARN_ON(ret); } if (buf == root->node) { WARN_ON(parent && parent != buf); + if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || + btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) + parent_start = buf->start; + else + parent_start = 0; - spin_lock(&root->node_lock); - root->node = cow; extent_buffer_get(cow); - spin_unlock(&root->node_lock); - - if (buf != root->commit_root) { - btrfs_free_extent(trans, root, buf->start, - buf->len, buf->start, - root->root_key.objectid, - btrfs_header_generation(buf), - level, 1); - } + tree_mod_log_set_root_pointer(root, cow, 1); + rcu_assign_pointer(root->node, cow); + + btrfs_free_tree_block(trans, root, buf, parent_start, + last_ref); free_extent_buffer(buf); add_root_to_dirty_list(root); } else { + if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) + parent_start = parent->start; + else + parent_start = 0; + + WARN_ON(trans->transid != btrfs_header_generation(parent)); + tree_mod_log_insert_key(root->fs_info, parent, parent_slot, + MOD_LOG_KEY_REPLACE, GFP_NOFS); btrfs_set_node_blockptr(parent, parent_slot, cow->start); - WARN_ON(trans->transid == 0); btrfs_set_node_ptr_generation(parent, parent_slot, trans->transid); btrfs_mark_buffer_dirty(parent); - WARN_ON(btrfs_header_generation(parent) != trans->transid); - btrfs_free_extent(trans, root, buf->start, buf->len, - parent_start, btrfs_header_owner(parent), - btrfs_header_generation(parent), level, 1); + 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); } if (unlock_orig) btrfs_tree_unlock(buf); - free_extent_buffer(buf); + free_extent_buffer_stale(buf); btrfs_mark_buffer_dirty(cow); *cow_ret = cow; return 0; } /* + * returns the logical address of the oldest predecessor of the given root. + * entries older than time_seq are ignored. + */ +static struct tree_mod_elem * +__tree_mod_log_oldest_root(struct btrfs_fs_info *fs_info, + struct extent_buffer *eb_root, u64 time_seq) +{ + struct tree_mod_elem *tm; + struct tree_mod_elem *found = NULL; + u64 root_logical = eb_root->start; + int looped = 0; + + if (!time_seq) + return NULL; + + /* + * the very last operation that's logged for a root is the replacement + * operation (if it is replaced at all). this has the index of the *new* + * root, making it the very first operation that's logged for this root. + */ + while (1) { + tm = tree_mod_log_search_oldest(fs_info, root_logical, + time_seq); + if (!looped && !tm) + 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 + * level 0. + */ + if (!tm) + break; + + /* + * if there's an operation that's not a root replacement, we + * found the oldest version of our root. normally, we'll find a + * MOD_LOG_KEY_REMOVE_WHILE_FREEING operation here. + */ + if (tm->op != MOD_LOG_ROOT_REPLACE) + break; + + found = tm; + root_logical = tm->old_root.logical; + looped = 1; + } + + /* if there's no old root to return, return what we found instead */ + if (!found) + found = tm; + + return found; +} + +/* + * tm is a pointer to the first operation to rewind within eb. then, all + * previous operations will be rewinded (until we reach something older than + * time_seq). + */ +static void +__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; + struct tree_mod_elem *tm = first_tm; + unsigned long o_dst; + unsigned long o_src; + unsigned long p_size = sizeof(struct btrfs_key_ptr); + + n = btrfs_header_nritems(eb); + 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 + * opposite of each operation here. + */ + 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); + btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); + btrfs_set_node_ptr_generation(eb, tm->slot, + tm->generation); + n++; + break; + case MOD_LOG_KEY_REPLACE: + BUG_ON(tm->slot >= n); + btrfs_set_node_key(eb, &tm->key, tm->slot); + btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); + btrfs_set_node_ptr_generation(eb, tm->slot, + tm->generation); + break; + case MOD_LOG_KEY_ADD: + /* if a move operation is needed it's in the log */ + n--; + break; + case MOD_LOG_MOVE_KEYS: + o_dst = btrfs_node_key_ptr_offset(tm->slot); + o_src = btrfs_node_key_ptr_offset(tm->move.dst_slot); + memmove_extent_buffer(eb, o_dst, o_src, + tm->move.nr_items * p_size); + break; + case MOD_LOG_ROOT_REPLACE: + /* + * this operation is special. for roots, this must be + * handled explicitly before rewinding. + * for non-roots, this operation may exist if the node + * was a root: root A -> child B; then A gets empty and + * B is promoted to the new root. in the mod log, we'll + * have a root-replace operation for B, a tree block + * that is no root. we simply ignore that operation. + */ + break; + } + next = rb_next(&tm->node); + if (!next) + break; + tm = container_of(next, struct tree_mod_elem, node); + 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 btrfs_path *path, + struct extent_buffer *eb, u64 time_seq) +{ + struct extent_buffer *eb_rewin; + struct tree_mod_elem *tm; + + if (!time_seq) + return eb; + + if (btrfs_header_level(eb) == 0) + return eb; + + tm = tree_mod_log_search(fs_info, eb->start, time_seq); + 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); + 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)); + btrfs_set_header_owner(eb_rewin, btrfs_header_owner(eb)); + btrfs_set_header_level(eb_rewin, btrfs_header_level(eb)); + } else { + eb_rewin = btrfs_clone_extent_buffer(eb); + if (!eb_rewin) { + btrfs_tree_read_unlock_blocking(eb); + free_extent_buffer(eb); + return NULL; + } + } + + btrfs_clear_path_blocking(path, NULL, BTRFS_READ_LOCK); + btrfs_tree_read_unlock_blocking(eb); + free_extent_buffer(eb); + + 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; +} + +/* + * get_old_root() rewinds the state of @root's root node to the given @time_seq + * value. If there are no changes, the current root->root_node is returned. If + * anything changed in between, there's a fresh buffer allocated on which the + * rewind operations are done. In any case, the returned buffer is read locked. + * Returns NULL on error (with no locks held). + */ +static inline struct extent_buffer * +get_old_root(struct btrfs_root *root, u64 time_seq) +{ + struct tree_mod_elem *tm; + 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_root = btrfs_read_lock_root_node(root); + tm = __tree_mod_log_oldest_root(root->fs_info, eb_root, time_seq); + if (!tm) + 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 = eb_root->start; + } + + tm = tree_mod_log_search(root->fs_info, logical, time_seq); + 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 { + 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, 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(root->fs_info, eb, time_seq, tm); + else + WARN_ON(btrfs_header_level(eb) != 0); + 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(); + + /* + * We do not need to cow a block if + * 1) this block is not created or changed in this transaction; + * 2) this block does not belong to TREE_RELOC tree; + * 3) the root is not forced COW. + * + * What is forced COW: + * when we create snapshot during commiting the transaction, + * after we've finished coping src root, we must COW the shared + * block to ensure the metadata consistency. + */ + if (btrfs_header_generation(buf) == trans->transid && + !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && + !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && + btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && + !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) + return 0; + return 1; +} + +/* * cows a single block, see __btrfs_cow_block for the real work. * This version of it has extra checks so that a block isn't cow'd more than * once per transaction, as long as it hasn't been written yet @@ -413,30 +1541,22 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, struct extent_buffer *parent, int parent_slot, - struct extent_buffer **cow_ret, u64 prealloc_dest) + struct extent_buffer **cow_ret) { 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 (btrfs_header_generation(buf) == trans->transid && - btrfs_header_owner(buf) == root->root_key.objectid && - !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) { + 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; - WARN_ON(prealloc_dest); return 0; } @@ -447,8 +1567,10 @@ noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, btrfs_set_lock_blocking(buf); ret = __btrfs_cow_block(trans, root, buf, parent, - parent_slot, cow_ret, search_start, 0, - prealloc_dest); + parent_slot, cow_ret, search_start, 0); + + trace_btrfs_cow_block(root, buf, *cow_ret); + return ret; } @@ -474,25 +1596,13 @@ static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) btrfs_disk_key_to_cpu(&k1, disk); - if (k1.objectid > k2->objectid) - return 1; - if (k1.objectid < k2->objectid) - return -1; - if (k1.type > k2->type) - return 1; - if (k1.type < k2->type) - return -1; - if (k1.offset > k2->offset) - return 1; - if (k1.offset < k2->offset) - return -1; - return 0; + return btrfs_comp_cpu_keys(&k1, k2); } /* * same as comp_keys only with two btrfs_key's */ -static int comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) +int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) { if (k1->objectid > k2->objectid) return 1; @@ -516,7 +1626,7 @@ static int 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; @@ -536,13 +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); @@ -556,14 +1662,6 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans, for (i = start_slot; i < end_slot; i++) { int close = 1; - if (!parent->map_token) { - map_extent_buffer(parent, - btrfs_node_key_ptr_offset(i), - sizeof(struct btrfs_key_ptr), - &parent->map_token, &parent->kaddr, - &parent->map_start, &parent->map_len, - KM_USER1); - } btrfs_node_key(parent, &disk_key, i); if (!progress_passed && comp_keys(&disk_key, progress) < 0) continue; @@ -586,27 +1684,26 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans, last_block = blocknr; continue; } - if (parent->map_token) { - unmap_extent_buffer(parent, parent->map_token, - KM_USER1); - parent->map_token = NULL; - } cur = btrfs_find_tree_block(root, blocknr, blocksize); if (cur) - uptodate = btrfs_buffer_uptodate(cur, gen); + uptodate = btrfs_buffer_uptodate(cur, gen, 0); 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 || !extent_buffer_uptodate(cur)) { + free_extent_buffer(cur); + return -EIO; + } } else if (!uptodate) { - btrfs_read_buffer(cur, gen); + err = btrfs_read_buffer(cur, gen); + if (err) { + free_extent_buffer(cur); + return err; + } } } if (search_start == 0) @@ -617,7 +1714,7 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans, err = __btrfs_cow_block(trans, root, cur, parent, i, &cur, search_start, min(16 * blocksize, - (end_slot - i) * blocksize), 0); + (end_slot - i) * blocksize)); if (err) { btrfs_tree_unlock(cur); free_extent_buffer(cur); @@ -629,11 +1726,6 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans, btrfs_tree_unlock(cur); free_extent_buffer(cur); } - if (parent->map_token) { - unmap_extent_buffer(parent, parent->map_token, - KM_USER1); - parent->map_token = NULL; - } return err; } @@ -651,122 +1743,6 @@ static inline unsigned int leaf_data_end(struct btrfs_root *root, return btrfs_item_offset_nr(leaf, nr - 1); } -/* - * extra debugging checks to make sure all the items in a key are - * well formed and in the proper order - */ -static int check_node(struct btrfs_root *root, struct btrfs_path *path, - int level) -{ - struct extent_buffer *parent = NULL; - struct extent_buffer *node = path->nodes[level]; - struct btrfs_disk_key parent_key; - struct btrfs_disk_key node_key; - int parent_slot; - int slot; - struct btrfs_key cpukey; - u32 nritems = btrfs_header_nritems(node); - - if (path->nodes[level + 1]) - parent = path->nodes[level + 1]; - - slot = path->slots[level]; - BUG_ON(nritems == 0); - if (parent) { - parent_slot = path->slots[level + 1]; - btrfs_node_key(parent, &parent_key, parent_slot); - btrfs_node_key(node, &node_key, 0); - BUG_ON(memcmp(&parent_key, &node_key, - sizeof(struct btrfs_disk_key))); - BUG_ON(btrfs_node_blockptr(parent, parent_slot) != - btrfs_header_bytenr(node)); - } - BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root)); - if (slot != 0) { - btrfs_node_key_to_cpu(node, &cpukey, slot - 1); - btrfs_node_key(node, &node_key, slot); - BUG_ON(comp_keys(&node_key, &cpukey) <= 0); - } - if (slot < nritems - 1) { - btrfs_node_key_to_cpu(node, &cpukey, slot + 1); - btrfs_node_key(node, &node_key, slot); - BUG_ON(comp_keys(&node_key, &cpukey) >= 0); - } - return 0; -} - -/* - * extra checking to make sure all the items in a leaf are - * well formed and in the proper order - */ -static int check_leaf(struct btrfs_root *root, struct btrfs_path *path, - int level) -{ - struct extent_buffer *leaf = path->nodes[level]; - struct extent_buffer *parent = NULL; - int parent_slot; - struct btrfs_key cpukey; - struct btrfs_disk_key parent_key; - struct btrfs_disk_key leaf_key; - int slot = path->slots[0]; - - u32 nritems = btrfs_header_nritems(leaf); - - if (path->nodes[level + 1]) - parent = path->nodes[level + 1]; - - if (nritems == 0) - return 0; - - if (parent) { - parent_slot = path->slots[level + 1]; - btrfs_node_key(parent, &parent_key, parent_slot); - btrfs_item_key(leaf, &leaf_key, 0); - - BUG_ON(memcmp(&parent_key, &leaf_key, - sizeof(struct btrfs_disk_key))); - BUG_ON(btrfs_node_blockptr(parent, parent_slot) != - btrfs_header_bytenr(leaf)); - } - if (slot != 0 && slot < nritems - 1) { - btrfs_item_key(leaf, &leaf_key, slot); - btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1); - if (comp_keys(&leaf_key, &cpukey) <= 0) { - btrfs_print_leaf(root, leaf); - printk(KERN_CRIT "slot %d offset bad key\n", slot); - BUG_ON(1); - } - if (btrfs_item_offset_nr(leaf, slot - 1) != - btrfs_item_end_nr(leaf, slot)) { - btrfs_print_leaf(root, leaf); - printk(KERN_CRIT "slot %d offset bad\n", slot); - BUG_ON(1); - } - } - if (slot < nritems - 1) { - btrfs_item_key(leaf, &leaf_key, slot); - btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1); - BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0); - if (btrfs_item_offset_nr(leaf, slot) != - btrfs_item_end_nr(leaf, slot + 1)) { - btrfs_print_leaf(root, leaf); - printk(KERN_CRIT "slot %d offset bad\n", slot); - BUG_ON(1); - } - } - BUG_ON(btrfs_item_offset_nr(leaf, 0) + - btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root)); - return 0; -} - -static noinline int check_block(struct btrfs_root *root, - struct btrfs_path *path, int level) -{ - return 0; - if (level == 0) - return check_leaf(root, path, level); - return check_node(root, path, level); -} /* * search for key in the extent_buffer. The items start at offset p, @@ -790,7 +1766,6 @@ static noinline int generic_bin_search(struct extent_buffer *eb, struct btrfs_disk_key *tmp = NULL; struct btrfs_disk_key unaligned; unsigned long offset; - char *map_token = NULL; char *kaddr = NULL; unsigned long map_start = 0; unsigned long map_len = 0; @@ -800,18 +1775,13 @@ static noinline int generic_bin_search(struct extent_buffer *eb, mid = (low + high) / 2; offset = p + mid * item_size; - if (!map_token || offset < map_start || + if (!kaddr || offset < map_start || (offset + sizeof(struct btrfs_disk_key)) > map_start + map_len) { - if (map_token) { - unmap_extent_buffer(eb, map_token, KM_USER0); - map_token = NULL; - } err = map_private_extent_buffer(eb, offset, sizeof(struct btrfs_disk_key), - &map_token, &kaddr, - &map_start, &map_len, KM_USER0); + &kaddr, &map_start, &map_len); if (!err) { tmp = (struct btrfs_disk_key *)(kaddr + offset - @@ -834,14 +1804,10 @@ static noinline int generic_bin_search(struct extent_buffer *eb, high = mid; else { *slot = mid; - if (map_token) - unmap_extent_buffer(eb, map_token, KM_USER0); return 0; } } *slot = low; - if (map_token) - unmap_extent_buffer(eb, map_token, KM_USER0); return 1; } @@ -852,20 +1818,40 @@ static noinline int generic_bin_search(struct extent_buffer *eb, static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, int level, int *slot) { - if (level == 0) { + if (level == 0) return generic_bin_search(eb, offsetof(struct btrfs_leaf, items), sizeof(struct btrfs_item), key, btrfs_header_nritems(eb), slot); - } else { + else return generic_bin_search(eb, offsetof(struct btrfs_node, ptrs), sizeof(struct btrfs_key_ptr), key, btrfs_header_nritems(eb), slot); - } - return -1; +} + +int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key, + int level, int *slot) +{ + return bin_search(eb, key, level, slot); +} + +static void root_add_used(struct btrfs_root *root, u32 size) +{ + spin_lock(&root->accounting_lock); + btrfs_set_root_used(&root->root_item, + btrfs_root_used(&root->root_item) + size); + spin_unlock(&root->accounting_lock); +} + +static void root_sub_used(struct btrfs_root *root, u32 size) +{ + spin_lock(&root->accounting_lock); + btrfs_set_root_used(&root->root_item, + btrfs_root_used(&root->root_item) - size); + spin_unlock(&root->accounting_lock); } /* given a node and slot number, this reads the blocks it points to. The @@ -876,6 +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)) @@ -883,9 +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; } /* @@ -905,7 +1899,6 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, int wret; int pslot; int orig_slot = path->slots[level]; - int err_on_enospc = 0; u64 orig_ptr; if (level == 0) @@ -913,14 +1906,16 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, mid = path->nodes[level]; - WARN_ON(!path->locks[level]); + WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK && + path->locks[level] != BTRFS_WRITE_LOCK_BLOCKING); WARN_ON(btrfs_header_generation(mid) != trans->transid); orig_ptr = btrfs_node_blockptr(mid, orig_slot); - if (level < BTRFS_MAX_LEVEL - 1) + if (level < BTRFS_MAX_LEVEL - 1) { parent = path->nodes[level + 1]; - pslot = path->slots[level + 1]; + pslot = path->slots[level + 1]; + } /* * deal with the case where there is only one pointer in the root @@ -934,21 +1929,23 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, /* promote the child to a root */ child = read_node_slot(root, mid, 0); - BUG_ON(!child); + if (!child) { + ret = -EROFS; + btrfs_std_error(root->fs_info, ret); + goto enospc; + } + btrfs_tree_lock(child); btrfs_set_lock_blocking(child); - ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 0); - BUG_ON(ret); - - spin_lock(&root->node_lock); - root->node = child; - spin_unlock(&root->node_lock); + ret = btrfs_cow_block(trans, root, child, mid, 0, &child); + if (ret) { + btrfs_tree_unlock(child); + free_extent_buffer(child); + goto enospc; + } - ret = btrfs_update_extent_ref(trans, root, child->start, - mid->start, child->start, - root->root_key.objectid, - trans->transid, level - 1); - BUG_ON(ret); + tree_mod_log_set_root_pointer(root, child, 1); + rcu_assign_pointer(root->node, child); add_root_to_dirty_list(root); btrfs_tree_unlock(child); @@ -959,27 +1956,23 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, btrfs_tree_unlock(mid); /* once for the path */ free_extent_buffer(mid); - ret = btrfs_free_extent(trans, root, mid->start, mid->len, - mid->start, root->root_key.objectid, - btrfs_header_generation(mid), - level, 1); + + root_sub_used(root, mid->len); + btrfs_free_tree_block(trans, root, mid, 0, 1); /* once for the root ptr */ - free_extent_buffer(mid); - return ret; + free_extent_buffer_stale(mid); + return 0; } if (btrfs_header_nritems(mid) > BTRFS_NODEPTRS_PER_BLOCK(root) / 4) return 0; - if (btrfs_header_nritems(mid) < 2) - err_on_enospc = 1; - left = read_node_slot(root, parent, pslot - 1); if (left) { btrfs_tree_lock(left); btrfs_set_lock_blocking(left); wret = btrfs_cow_block(trans, root, left, - parent, pslot - 1, &left, 0); + parent, pslot - 1, &left); if (wret) { ret = wret; goto enospc; @@ -990,7 +1983,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, btrfs_tree_lock(right); btrfs_set_lock_blocking(right); wret = btrfs_cow_block(trans, root, right, - parent, pslot + 1, &right, 0); + parent, pslot + 1, &right); if (wret) { ret = wret; goto enospc; @@ -1003,8 +1996,6 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, wret = push_node_left(trans, root, left, mid, 1); if (wret < 0) ret = wret; - if (btrfs_header_nritems(mid) < 2) - err_on_enospc = 1; } /* @@ -1015,27 +2006,18 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, if (wret < 0 && wret != -ENOSPC) ret = wret; if (btrfs_header_nritems(right) == 0) { - u64 bytenr = right->start; - u64 generation = btrfs_header_generation(parent); - u32 blocksize = right->len; - clean_tree_block(trans, root, right); btrfs_tree_unlock(right); - free_extent_buffer(right); + 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); right = NULL; - wret = del_ptr(trans, root, path, level + 1, pslot + - 1); - if (wret) - ret = wret; - wret = btrfs_free_extent(trans, root, bytenr, - blocksize, parent->start, - btrfs_header_owner(parent), - generation, level, 1); - if (wret) - ret = wret; } else { struct btrfs_disk_key right_key; btrfs_node_key(right, &right_key, 0); + tree_mod_log_set_node_key(root->fs_info, parent, + pslot + 1, 0); btrfs_set_node_key(parent, &right_key, pslot + 1); btrfs_mark_buffer_dirty(parent); } @@ -1050,7 +2032,11 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, * otherwise we would have pulled some pointers from the * right */ - BUG_ON(!left); + if (!left) { + ret = -EROFS; + btrfs_std_error(root->fs_info, ret); + goto enospc; + } wret = balance_node_right(trans, root, mid, left); if (wret < 0) { ret = wret; @@ -1064,28 +2050,19 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, BUG_ON(wret == 1); } if (btrfs_header_nritems(mid) == 0) { - /* we've managed to empty the middle node, drop it */ - u64 root_gen = btrfs_header_generation(parent); - u64 bytenr = mid->start; - u32 blocksize = mid->len; - clean_tree_block(trans, root, mid); btrfs_tree_unlock(mid); - free_extent_buffer(mid); + 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); mid = NULL; - wret = del_ptr(trans, root, path, level + 1, pslot); - if (wret) - ret = wret; - wret = btrfs_free_extent(trans, root, bytenr, blocksize, - parent->start, - btrfs_header_owner(parent), - root_gen, level, 1); - if (wret) - ret = wret; } else { /* 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, + pslot, 0); btrfs_set_node_key(parent, &mid_key, pslot); btrfs_mark_buffer_dirty(parent); } @@ -1108,7 +2085,6 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, } } /* double check we haven't messed things up */ - check_block(root, path, level); if (orig_ptr != btrfs_node_blockptr(path->nodes[level], path->slots[level])) BUG(); @@ -1141,18 +2117,17 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, int wret; int pslot; int orig_slot = path->slots[level]; - u64 orig_ptr; if (level == 0) return 1; mid = path->nodes[level]; WARN_ON(btrfs_header_generation(mid) != trans->transid); - orig_ptr = btrfs_node_blockptr(mid, orig_slot); - if (level < BTRFS_MAX_LEVEL - 1) + if (level < BTRFS_MAX_LEVEL - 1) { parent = path->nodes[level + 1]; - pslot = path->slots[level + 1]; + pslot = path->slots[level + 1]; + } if (!parent) return 1; @@ -1171,7 +2146,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, wret = 1; } else { ret = btrfs_cow_block(trans, root, left, parent, - pslot - 1, &left, 0); + pslot - 1, &left); if (ret) wret = 1; else { @@ -1185,6 +2160,8 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, struct btrfs_disk_key disk_key; orig_slot += left_nr; btrfs_node_key(mid, &disk_key, 0); + tree_mod_log_set_node_key(root->fs_info, parent, + pslot, 0); btrfs_set_node_key(parent, &disk_key, pslot); btrfs_mark_buffer_dirty(parent); if (btrfs_header_nritems(left) > orig_slot) { @@ -1222,7 +2199,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, } else { ret = btrfs_cow_block(trans, root, right, parent, pslot + 1, - &right, 0); + &right); if (ret) wret = 1; else { @@ -1236,6 +2213,8 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, struct btrfs_disk_key disk_key; btrfs_node_key(right, &disk_key, 0); + tree_mod_log_set_node_key(root->fs_info, parent, + pslot + 1, 0); btrfs_set_node_key(parent, &disk_key, pslot + 1); btrfs_mark_buffer_dirty(parent); @@ -1262,9 +2241,9 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, * readahead one full node of leaves, finding things that are close * to the block in 'slot', and triggering ra on them. */ -static noinline void reada_for_search(struct btrfs_root *root, - struct btrfs_path *path, - int level, int slot, u64 objectid) +static void reada_for_search(struct btrfs_root *root, + struct btrfs_path *path, + int level, int slot, u64 objectid) { struct extent_buffer *node; struct btrfs_disk_key disk_key; @@ -1272,6 +2251,7 @@ static noinline void reada_for_search(struct btrfs_root *root, u64 search; u64 target; u64 nread = 0; + u64 gen; int direction = path->reada; struct extent_buffer *eb; u32 nr; @@ -1298,6 +2278,7 @@ static noinline void reada_for_search(struct btrfs_root *root, nritems = btrfs_header_nritems(node); nr = slot; + while (1) { if (direction < 0) { if (nr == 0) @@ -1316,8 +2297,8 @@ static noinline void reada_for_search(struct btrfs_root *root, search = btrfs_node_blockptr(node, nr); if ((search <= target && target - search <= 65536) || (search > target && search - target <= 65536)) { - readahead_tree_block(root, search, blocksize, - btrfs_node_ptr_generation(node, nr)); + gen = btrfs_node_ptr_generation(node, nr); + readahead_tree_block(root, search, blocksize, gen); nread += blocksize; } nscan++; @@ -1326,12 +2307,8 @@ static noinline 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; @@ -1340,51 +2317,42 @@ 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]; + parent = path->nodes[level + 1]; if (!parent) - return 0; + return; nritems = btrfs_header_nritems(parent); - slot = path->slots[level]; + slot = path->slots[level + 1]; blocksize = btrfs_level_size(root, level); if (slot > 0) { block1 = btrfs_node_blockptr(parent, slot - 1); gen = btrfs_node_ptr_generation(parent, slot - 1); eb = btrfs_find_tree_block(root, block1, blocksize); - if (eb && btrfs_buffer_uptodate(eb, gen)) + /* + * if we get -eagain from btrfs_buffer_uptodate, we + * don't want to return eagain here. That will loop + * forever + */ + if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0) block1 = 0; free_extent_buffer(eb); } - if (slot < nritems) { + if (slot + 1 < nritems) { block2 = btrfs_node_blockptr(parent, slot + 1); gen = btrfs_node_ptr_generation(parent, slot + 1); eb = btrfs_find_tree_block(root, block2, blocksize); - if (eb && btrfs_buffer_uptodate(eb, gen)) + if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0) block2 = 0; free_extent_buffer(eb); } - if (block1 || block2) { - ret = -EAGAIN; - btrfs_release_path(root, path); - 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 (block1) { - 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); } @@ -1402,7 +2370,8 @@ static noinline int reada_for_balance(struct btrfs_root *root, * if lowest_unlock is 1, level 0 won't be unlocked */ static noinline void unlock_up(struct btrfs_path *path, int level, - int lowest_unlock) + int lowest_unlock, int min_write_lock_level, + int *write_lock_level) { int i; int skip_level = level; @@ -1432,8 +2401,13 @@ static noinline void unlock_up(struct btrfs_path *path, int level, t = path->nodes[i]; if (i >= lowest_unlock && i > skip_level && path->locks[i]) { - btrfs_tree_unlock(t); + btrfs_tree_unlock_rw(t, path->locks[i]); path->locks[i] = 0; + if (write_lock_level && + i > min_write_lock_level && + i <= *write_lock_level) { + *write_lock_level = i - 1; + } } } } @@ -1451,7 +2425,7 @@ noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) { int i; - if (path->keep_locks || path->lowest_level) + if (path->keep_locks) return; for (i = level; i < BTRFS_MAX_LEVEL; i++) { @@ -1459,12 +2433,244 @@ noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) continue; if (!path->locks[i]) continue; - btrfs_tree_unlock(path->nodes[i]); + btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); path->locks[i] = 0; } } /* + * helper function for btrfs_search_slot. The goal is to find a block + * in cache without setting the path to blocking. If we find the block + * we return zero and the path is unchanged. + * + * If we can't find the block, we set the path blocking and do some + * reada. -EAGAIN is returned and the search must be repeated. + */ +static int +read_block_for_search(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct btrfs_path *p, + struct extent_buffer **eb_ret, int level, int slot, + struct btrfs_key *key, u64 time_seq) +{ + u64 blocknr; + u64 gen; + u32 blocksize; + struct extent_buffer *b = *eb_ret; + struct extent_buffer *tmp; + int ret; + + blocknr = btrfs_node_blockptr(b, slot); + gen = btrfs_node_ptr_generation(b, slot); + blocksize = btrfs_level_size(root, level - 1); + + tmp = btrfs_find_tree_block(root, blocknr, blocksize); + if (tmp) { + /* first we do an atomic uptodate check */ + if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { + *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 + */ + 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; + } + + /* + * reduce lock contention at high levels + * of the btree by dropping locks before + * we read. Don't release the lock on the current + * level because we need to walk this node to figure + * out which blocks to read. + */ + btrfs_unlock_up_safe(p, level + 1); + btrfs_set_path_blocking(p); + + free_extent_buffer(tmp); + if (p->reada) + reada_for_search(root, p, level, slot, key->objectid); + + btrfs_release_path(p); + + ret = -EAGAIN; + tmp = read_tree_block(root, blocknr, blocksize, 0); + if (tmp) { + /* + * If the read above didn't mark this buffer up to date, + * it will never end up being up to date. Set ret to EIO now + * and give up so that our caller doesn't loop forever + * on our EAGAINs. + */ + if (!btrfs_buffer_uptodate(tmp, 0, 0)) + ret = -EIO; + free_extent_buffer(tmp); + } + return ret; +} + +/* + * helper function for btrfs_search_slot. This does all of the checks + * for node-level blocks and does any balancing required based on + * the ins_len. + * + * If no extra work was required, zero is returned. If we had to + * drop the path, -EAGAIN is returned and btrfs_search_slot must + * start over + */ +static int +setup_nodes_for_search(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct btrfs_path *p, + struct extent_buffer *b, int level, int ins_len, + int *write_lock_level) +{ + int ret; + if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= + BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { + int sret; + + if (*write_lock_level < level + 1) { + *write_lock_level = level + 1; + btrfs_release_path(p); + 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); + + BUG_ON(sret > 0); + if (sret) { + ret = sret; + goto done; + } + b = p->nodes[level]; + } else if (ins_len < 0 && btrfs_header_nritems(b) < + BTRFS_NODEPTRS_PER_BLOCK(root) / 2) { + int sret; + + if (*write_lock_level < level + 1) { + *write_lock_level = level + 1; + btrfs_release_path(p); + 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); + + if (sret) { + ret = sret; + goto done; + } + b = p->nodes[level]; + if (!b) { + btrfs_release_path(p); + goto again; + } + BUG_ON(btrfs_header_nritems(b) == 1); + } + return 0; + +again: + ret = -EAGAIN; +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 * level of the path (level 0) @@ -1482,32 +2688,93 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root ins_len, int cow) { struct extent_buffer *b; - struct extent_buffer *tmp; int slot; int ret; + int err; int level; - int should_reada = p->reada; int lowest_unlock = 1; - int blocksize; + int root_lock; + /* everything at write_lock_level or lower must be write locked */ + int write_lock_level = 0; u8 lowest_level = 0; - u64 blocknr; - u64 gen; - struct btrfs_key prealloc_block; + 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) + if (ins_len < 0) { lowest_unlock = 2; - prealloc_block.objectid = 0; + /* when we are removing items, we might have to go up to level + * two as we update tree pointers Make sure we keep write + * for those levels as well + */ + write_lock_level = 2; + } else if (ins_len > 0) { + /* + * for inserting items, make sure we have a write lock on + * level 1 so we can update keys + */ + write_lock_level = 1; + } + + if (!cow) + write_lock_level = -1; + + if (cow && (p->keep_locks || p->lowest_level)) + write_lock_level = BTRFS_MAX_LEVEL; + + min_write_lock_level = write_lock_level; again: - if (p->skip_locking) - b = btrfs_root_node(root); - else - b = btrfs_lock_root_node(root); + prev_cmp = -1; + /* + * we try very hard to do read locks on the root + */ + root_lock = BTRFS_READ_LOCK; + level = 0; + if (p->search_commit_root) { + /* + * 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 { + if (p->skip_locking) { + b = btrfs_root_node(root); + level = btrfs_header_level(b); + } else { + /* we don't know the level of the root node + * until we actually have it read locked + */ + b = btrfs_read_lock_root_node(root); + level = btrfs_header_level(b); + if (level <= write_lock_level) { + /* whoops, must trade for write lock */ + btrfs_tree_read_unlock(b); + free_extent_buffer(b); + b = btrfs_lock_root_node(root); + root_lock = BTRFS_WRITE_LOCK; + + /* the level might have changed, check again */ + level = btrfs_header_level(b); + } + } + } + p->nodes[level] = b; + if (!p->skip_locking) + p->locks[level] = root_lock; while (b) { level = btrfs_header_level(b); @@ -1516,74 +2783,41 @@ again: * setup the path here so we can release it under lock * contention with the cow code */ - p->nodes[level] = b; - if (!p->skip_locking) - p->locks[level] = 1; - if (cow) { - int wret; - - /* is a cow on this block not required */ - if (btrfs_header_generation(b) == trans->transid && - btrfs_header_owner(b) == root->root_key.objectid && - !btrfs_header_flag(b, BTRFS_HEADER_FLAG_WRITTEN)) { + /* + * if we don't really need to cow this block + * then we don't want to set the path blocking, + * so we test it here + */ + if (!should_cow_block(trans, root, b)) goto cow_done; - } - /* ok, we have to cow, is our old prealloc the right - * size? - */ - if (prealloc_block.objectid && - prealloc_block.offset != b->len) { - btrfs_release_path(root, p); - btrfs_free_reserved_extent(root, - prealloc_block.objectid, - prealloc_block.offset); - prealloc_block.objectid = 0; - goto again; - } + btrfs_set_path_blocking(p); /* - * for higher level blocks, try not to allocate blocks - * with the block and the parent locks held. + * must have write locks on this node and the + * parent */ - if (level > 0 && !prealloc_block.objectid) { - u32 size = b->len; - u64 hint = b->start; - - btrfs_release_path(root, p); - ret = btrfs_reserve_extent(trans, root, - size, size, 0, - hint, (u64)-1, - &prealloc_block, 0); - BUG_ON(ret); + 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; } - btrfs_set_path_blocking(p); - - wret = btrfs_cow_block(trans, root, b, - p->nodes[level + 1], - p->slots[level + 1], - &b, prealloc_block.objectid); - prealloc_block.objectid = 0; - if (wret) { - free_extent_buffer(b); - ret = wret; + err = btrfs_cow_block(trans, root, b, + p->nodes[level + 1], + p->slots[level + 1], &b); + if (err) { + ret = err; goto done; } } cow_done: - BUG_ON(!cow && ins_len); - if (level != btrfs_header_level(b)) - WARN_ON(1); - level = btrfs_header_level(b); - p->nodes[level] = b; - if (!p->skip_locking) - p->locks[level] = 1; - - btrfs_clear_path_blocking(p, NULL); + btrfs_clear_path_blocking(p, NULL, 0); /* * we have a lock on b and as long as we aren't changing @@ -1591,148 +2825,118 @@ 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 = check_block(root, p, level); - if (ret) { - ret = -1; - goto done; + if (u < BTRFS_MAX_LEVEL && p->locks[u]) { + btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); + p->locks[u] = 0; + } } - ret = bin_search(b, key, level, &slot); + ret = key_search(b, key, level, &prev_cmp, &slot); if (level != 0) { - if (ret && slot > 0) + int dec = 0; + if (ret && slot > 0) { + dec = 1; slot -= 1; + } p->slots[level] = slot; - if ((p->search_for_split || ins_len > 0) && - btrfs_header_nritems(b) >= - BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { - int sret; - - sret = reada_for_balance(root, p, level); - if (sret) - goto again; - - btrfs_set_path_blocking(p); - sret = split_node(trans, root, p, level); - btrfs_clear_path_blocking(p, NULL); - - BUG_ON(sret > 0); - if (sret) { - ret = sret; - goto done; - } - b = p->nodes[level]; - slot = p->slots[level]; - } else if (ins_len < 0 && - btrfs_header_nritems(b) < - BTRFS_NODEPTRS_PER_BLOCK(root) / 4) { - int sret; - - sret = reada_for_balance(root, p, level); - if (sret) - goto again; - - btrfs_set_path_blocking(p); - sret = balance_level(trans, root, p, level); - btrfs_clear_path_blocking(p, NULL); + err = setup_nodes_for_search(trans, root, p, b, level, + ins_len, &write_lock_level); + if (err == -EAGAIN) + goto again; + if (err) { + ret = err; + goto done; + } + b = p->nodes[level]; + slot = p->slots[level]; - if (sret) { - ret = sret; - goto done; - } - b = p->nodes[level]; - if (!b) { - btrfs_release_path(NULL, p); - goto again; - } - slot = p->slots[level]; - BUG_ON(btrfs_header_nritems(b) == 1); + /* + * slot 0 is special, if we change the key + * we have to update the parent pointer + * which means we must have a write lock + * on the parent + */ + if (slot == 0 && ins_len && + write_lock_level < level + 1) { + write_lock_level = level + 1; + btrfs_release_path(p); + goto again; } - unlock_up(p, level, lowest_unlock); - /* this is only true while dropping a snapshot */ + unlock_up(p, level, lowest_unlock, + min_write_lock_level, &write_lock_level); + if (level == lowest_level) { - ret = 0; + if (dec) + p->slots[level]++; goto done; } - blocknr = btrfs_node_blockptr(b, slot); - gen = btrfs_node_ptr_generation(b, slot); - blocksize = btrfs_level_size(root, level - 1); - - tmp = btrfs_find_tree_block(root, blocknr, blocksize); - if (tmp && btrfs_buffer_uptodate(tmp, gen)) { - b = tmp; - } else { - /* - * reduce lock contention at high levels - * of the btree by dropping locks before - * we read. - */ - if (level > 0) { - btrfs_release_path(NULL, p); - if (tmp) - free_extent_buffer(tmp); - if (should_reada) - reada_for_search(root, p, - level, slot, - key->objectid); - - tmp = read_tree_block(root, blocknr, - blocksize, gen); - if (tmp) - free_extent_buffer(tmp); - goto again; - } else { - btrfs_set_path_blocking(p); - if (tmp) - free_extent_buffer(tmp); - if (should_reada) - reada_for_search(root, p, - level, slot, - key->objectid); - b = read_node_slot(root, b, slot); - } + err = read_block_for_search(trans, root, p, + &b, level, slot, key, 0); + if (err == -EAGAIN) + goto again; + if (err) { + ret = err; + goto done; } - if (!p->skip_locking) { - int lret; - - btrfs_clear_path_blocking(p, NULL); - lret = btrfs_try_spin_lock(b); - if (!lret) { - btrfs_set_path_blocking(p); - btrfs_tree_lock(b); - btrfs_clear_path_blocking(p, b); + if (!p->skip_locking) { + level = btrfs_header_level(b); + if (level <= write_lock_level) { + err = btrfs_try_tree_write_lock(b); + if (!err) { + btrfs_set_path_blocking(p); + btrfs_tree_lock(b); + btrfs_clear_path_blocking(p, b, + BTRFS_WRITE_LOCK); + } + p->locks[level] = BTRFS_WRITE_LOCK; + } else { + err = btrfs_try_tree_read_lock(b); + if (!err) { + btrfs_set_path_blocking(p); + btrfs_tree_read_lock(b); + btrfs_clear_path_blocking(p, b, + BTRFS_READ_LOCK); + } + p->locks[level] = BTRFS_READ_LOCK; } + p->nodes[level] = b; } } else { p->slots[level] = slot; if (ins_len > 0 && btrfs_leaf_free_space(root, b) < ins_len) { - int sret; + if (write_lock_level < 1) { + write_lock_level = 1; + btrfs_release_path(p); + goto again; + } btrfs_set_path_blocking(p); - sret = split_leaf(trans, root, key, - p, ins_len, ret == 0); - btrfs_clear_path_blocking(p, NULL); + err = split_leaf(trans, root, key, + p, ins_len, ret == 0); + btrfs_clear_path_blocking(p, NULL, 0); - BUG_ON(sret > 0); - if (sret) { - ret = sret; + BUG_ON(err > 0); + if (err) { + ret = err; goto done; } } if (!p->search_for_split) - unlock_up(p, level, lowest_unlock); + unlock_up(p, level, lowest_unlock, + min_write_lock_level, &write_lock_level); goto done; } } @@ -1742,144 +2946,197 @@ done: * we don't really know what they plan on doing with the path * from here on, so for now just mark it as blocking */ - btrfs_set_path_blocking(p); - if (prealloc_block.objectid) { - btrfs_free_reserved_extent(root, - prealloc_block.objectid, - prealloc_block.offset); - } + if (!p->leave_spinning) + btrfs_set_path_blocking(p); + if (ret < 0) + btrfs_release_path(p); return ret; } -int btrfs_merge_path(struct btrfs_trans_handle *trans, - struct btrfs_root *root, - struct btrfs_key *node_keys, - u64 *nodes, int lowest_level) +/* + * Like btrfs_search_slot, this looks for a key in the given tree. It uses the + * current state of the tree together with the operations recorded in the tree + * modification log to search for the key in a previous version of this tree, as + * denoted by the time_seq parameter. + * + * Naturally, there is no support for insert, delete or cow operations. + * + * The resulting path and return value will be set up as if we called + * btrfs_search_slot at that point in time with ins_len and cow both set to 0. + */ +int btrfs_search_old_slot(struct btrfs_root *root, struct btrfs_key *key, + struct btrfs_path *p, u64 time_seq) { - struct extent_buffer *eb; - struct extent_buffer *parent; - struct btrfs_key key; - u64 bytenr; - u64 generation; - u32 blocksize; - int level; + struct extent_buffer *b; int slot; - int key_match; int ret; + int err; + int level; + int lowest_unlock = 1; + u8 lowest_level = 0; + int prev_cmp = -1; - eb = btrfs_lock_root_node(root); - ret = btrfs_cow_block(trans, root, eb, NULL, 0, &eb, 0); - BUG_ON(ret); - - btrfs_set_lock_blocking(eb); - - parent = eb; - while (1) { - level = btrfs_header_level(parent); - if (level == 0 || level <= lowest_level) - break; + lowest_level = p->lowest_level; + WARN_ON(p->nodes[0] != NULL); - ret = bin_search(parent, &node_keys[lowest_level], level, - &slot); - if (ret && slot > 0) - slot--; + if (p->search_commit_root) { + BUG_ON(time_seq); + return btrfs_search_slot(NULL, root, key, p, 0, 0); + } - bytenr = btrfs_node_blockptr(parent, slot); - if (nodes[level - 1] == bytenr) - break; +again: + b = get_old_root(root, time_seq); + level = btrfs_header_level(b); + p->locks[level] = BTRFS_READ_LOCK; - blocksize = btrfs_level_size(root, level - 1); - generation = btrfs_node_ptr_generation(parent, slot); - btrfs_node_key_to_cpu(eb, &key, slot); - key_match = !memcmp(&key, &node_keys[level - 1], sizeof(key)); + while (b) { + level = btrfs_header_level(b); + p->nodes[level] = b; + btrfs_clear_path_blocking(p, NULL, 0); - if (generation == trans->transid) { - eb = read_tree_block(root, bytenr, blocksize, - generation); - btrfs_tree_lock(eb); - btrfs_set_lock_blocking(eb); - } + /* + * we have a lock on b and as long as we aren't changing + * the tree, there is no way to for the items in b to change. + * It is safe to drop the lock on our parent before we + * go through the expensive btree search on b. + */ + btrfs_unlock_up_safe(p, level + 1); /* - * if node keys match and node pointer hasn't been modified - * in the running transaction, we can merge the path. for - * blocks owened by reloc trees, the node pointer check is - * skipped, this is because these blocks are fully controlled - * by the space balance code, no one else can modify them. + * Since we can unwind eb's we want to do a real search every + * time. */ - if (!nodes[level - 1] || !key_match || - (generation == trans->transid && - btrfs_header_owner(eb) != BTRFS_TREE_RELOC_OBJECTID)) { - if (level == 1 || level == lowest_level + 1) { - if (generation == trans->transid) { - btrfs_tree_unlock(eb); - free_extent_buffer(eb); - } - break; - } + prev_cmp = -1; + ret = key_search(b, key, level, &prev_cmp, &slot); - if (generation != trans->transid) { - eb = read_tree_block(root, bytenr, blocksize, - generation); - btrfs_tree_lock(eb); - btrfs_set_lock_blocking(eb); + if (level != 0) { + int dec = 0; + if (ret && slot > 0) { + dec = 1; + slot -= 1; } + p->slots[level] = slot; + unlock_up(p, level, lowest_unlock, 0, NULL); - ret = btrfs_cow_block(trans, root, eb, parent, slot, - &eb, 0); - BUG_ON(ret); + if (level == lowest_level) { + if (dec) + p->slots[level]++; + goto done; + } - if (root->root_key.objectid == - BTRFS_TREE_RELOC_OBJECTID) { - if (!nodes[level - 1]) { - nodes[level - 1] = eb->start; - memcpy(&node_keys[level - 1], &key, - sizeof(node_keys[0])); - } else { - WARN_ON(1); - } + err = read_block_for_search(NULL, root, p, &b, level, + slot, key, time_seq); + if (err == -EAGAIN) + goto again; + if (err) { + ret = err; + goto done; } - btrfs_tree_unlock(parent); - free_extent_buffer(parent); - parent = eb; - continue; + level = btrfs_header_level(b); + err = btrfs_try_tree_read_lock(b); + if (!err) { + btrfs_set_path_blocking(p); + btrfs_tree_read_lock(b); + 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; + } else { + p->slots[level] = slot; + unlock_up(p, level, lowest_unlock, 0, NULL); + goto done; } + } + ret = 1; +done: + if (!p->leave_spinning) + btrfs_set_path_blocking(p); + if (ret < 0) + btrfs_release_path(p); - btrfs_set_node_blockptr(parent, slot, nodes[level - 1]); - btrfs_set_node_ptr_generation(parent, slot, trans->transid); - btrfs_mark_buffer_dirty(parent); + return ret; +} - ret = btrfs_inc_extent_ref(trans, root, - nodes[level - 1], - blocksize, parent->start, - btrfs_header_owner(parent), - btrfs_header_generation(parent), - level - 1); - BUG_ON(ret); +/* + * 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; - /* - * If the block was created in the running transaction, - * it's possible this is the last reference to it, so we - * should drop the subtree. - */ - if (generation == trans->transid) { - ret = btrfs_drop_subtree(trans, root, eb, parent); - BUG_ON(ret); - btrfs_tree_unlock(eb); - free_extent_buffer(eb); +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 { - ret = btrfs_free_extent(trans, root, bytenr, - blocksize, parent->start, - btrfs_header_owner(parent), - btrfs_header_generation(parent), - level - 1, 1); - BUG_ON(ret); + --p->slots[0]; } - break; } - btrfs_tree_unlock(parent); - free_extent_buffer(parent); return 0; } @@ -1890,15 +3147,11 @@ int btrfs_merge_path(struct btrfs_trans_handle *trans, * fixing up pointers when a given leaf/node is not in slot 0 of the * higher levels * - * If this fails to write a tree block, it returns -1, but continues - * fixing up the blocks in ram so the tree is consistent. */ -static int fixup_low_keys(struct btrfs_trans_handle *trans, - struct btrfs_root *root, struct btrfs_path *path, - struct btrfs_disk_key *key, int level) +static void fixup_low_keys(struct btrfs_root *root, struct btrfs_path *path, + struct btrfs_disk_key *key, int level) { int i; - int ret = 0; struct extent_buffer *t; for (i = level; i < BTRFS_MAX_LEVEL; i++) { @@ -1906,12 +3159,12 @@ static int 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, tslot, 1); btrfs_set_node_key(t, key, tslot); btrfs_mark_buffer_dirty(path->nodes[i]); if (tslot != 0) break; } - return ret; } /* @@ -1920,9 +3173,8 @@ static int 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 */ -int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, - struct btrfs_root *root, struct btrfs_path *path, - struct btrfs_key *new_key) +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; struct extent_buffer *eb; @@ -1932,21 +3184,18 @@ int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, slot = path->slots[0]; if (slot > 0) { btrfs_item_key(eb, &disk_key, slot - 1); - if (comp_keys(&disk_key, new_key) >= 0) - return -1; + BUG_ON(comp_keys(&disk_key, new_key) >= 0); } if (slot < btrfs_header_nritems(eb) - 1) { btrfs_item_key(eb, &disk_key, slot + 1); - if (comp_keys(&disk_key, new_key) <= 0) - return -1; + BUG_ON(comp_keys(&disk_key, new_key) <= 0); } btrfs_cpu_key_to_disk(&disk_key, new_key); 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); - return 0; + fixup_low_keys(root, path, &disk_key, 1); } /* @@ -1992,12 +3241,22 @@ static int push_node_left(struct btrfs_trans_handle *trans, } else push_items = min(src_nritems - 8, 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) { + /* + * 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) * @@ -2008,9 +3267,6 @@ static int push_node_left(struct btrfs_trans_handle *trans, btrfs_mark_buffer_dirty(src); btrfs_mark_buffer_dirty(dst); - ret = btrfs_update_ref(trans, root, src, dst, dst_nritems, push_items); - BUG_ON(ret); - return ret; } @@ -2054,11 +3310,18 @@ static int balance_node_right(struct btrfs_trans_handle *trans, if (max_push < push_items) push_items = max_push; + tree_mod_log_eb_move(root->fs_info, dst, push_items, 0, dst_nritems); memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), btrfs_node_key_ptr_offset(0), (dst_nritems) * sizeof(struct btrfs_key_ptr)); + 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), @@ -2070,9 +3333,6 @@ static int balance_node_right(struct btrfs_trans_handle *trans, btrfs_mark_buffer_dirty(src); btrfs_mark_buffer_dirty(dst); - ret = btrfs_update_ref(trans, root, src, dst, 0, push_items); - BUG_ON(ret); - return ret; } @@ -2092,7 +3352,6 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans, struct extent_buffer *c; struct extent_buffer *old; struct btrfs_disk_key lower_key; - int ret; BUG_ON(path->nodes[level]); BUG_ON(path->nodes[level-1] != root->node); @@ -2104,25 +3363,26 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans, btrfs_node_key(lower, &lower_key, 0); c = btrfs_alloc_free_block(trans, root, root->nodesize, 0, - root->root_key.objectid, trans->transid, + root->root_key.objectid, &lower_key, level, root->node->start, 0); if (IS_ERR(c)) return PTR_ERR(c); - memset_extent_buffer(c, 0, 0, root->nodesize); + root_add_used(root, root->nodesize); + + memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); btrfs_set_header_nritems(c, 1); btrfs_set_header_level(c, level); btrfs_set_header_bytenr(c, c->start); btrfs_set_header_generation(c, trans->transid); + 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); @@ -2133,16 +3393,9 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans, btrfs_mark_buffer_dirty(c); - spin_lock(&root->node_lock); old = root->node; - root->node = c; - spin_unlock(&root->node_lock); - - ret = btrfs_update_extent_ref(trans, root, lower->start, - lower->start, c->start, - root->root_key.objectid, - trans->transid, level - 1); - BUG_ON(ret); + tree_mod_log_set_root_pointer(root, c, 0); + rcu_assign_pointer(root->node, c); /* the super has an extra ref to root->node */ free_extent_buffer(old); @@ -2150,7 +3403,7 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans, add_root_to_dirty_list(root); extent_buffer_get(c); path->nodes[level] = c; - path->locks[level] = 1; + path->locks[level] = BTRFS_WRITE_LOCK; path->slots[level] = 0; return 0; } @@ -2161,36 +3414,42 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans, * * slot and level indicate where you want the key to go, and * blocknr is the block the key points to. - * - * returns zero on success and < 0 on any error */ -static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root - *root, struct btrfs_path *path, struct btrfs_disk_key - *key, u64 bytenr, int slot, int level) +static void insert_ptr(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct btrfs_path *path, + struct btrfs_disk_key *key, u64 bytenr, + int slot, int level) { struct extent_buffer *lower; int nritems; + int ret; BUG_ON(!path->nodes[level]); + btrfs_assert_tree_locked(path->nodes[level]); lower = path->nodes[level]; nritems = btrfs_header_nritems(lower); - if (slot > nritems) - BUG(); - if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) - BUG(); + BUG_ON(slot > nritems); + BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(root)); if (slot != nritems) { + if (level) + tree_mod_log_eb_move(root->fs_info, lower, slot + 1, + slot, nritems - slot); memmove_extent_buffer(lower, btrfs_node_key_ptr_offset(slot + 1), btrfs_node_key_ptr_offset(slot), (nritems - slot) * sizeof(struct btrfs_key_ptr)); } + if (level) { + ret = tree_mod_log_insert_key(root->fs_info, lower, slot, + MOD_LOG_KEY_ADD, GFP_NOFS); + BUG_ON(ret < 0); + } btrfs_set_node_key(lower, key, slot); btrfs_set_node_blockptr(lower, slot, bytenr); WARN_ON(trans->transid == 0); btrfs_set_node_ptr_generation(lower, slot, trans->transid); btrfs_set_header_nritems(lower, nritems + 1); btrfs_mark_buffer_dirty(lower); - return 0; } /* @@ -2211,13 +3470,21 @@ static noinline int split_node(struct btrfs_trans_handle *trans, struct btrfs_disk_key disk_key; int mid; int ret; - int wret; u32 c_nritems; 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; @@ -2232,29 +3499,35 @@ static noinline int split_node(struct btrfs_trans_handle *trans, } c_nritems = btrfs_header_nritems(c); + mid = (c_nritems + 1) / 2; + btrfs_node_key(c, &disk_key, mid); - split = btrfs_alloc_free_block(trans, root, root->nodesize, - path->nodes[level + 1]->start, + split = btrfs_alloc_free_block(trans, root, root->nodesize, 0, root->root_key.objectid, - trans->transid, level, c->start, 0); + &disk_key, level, c->start, 0); if (IS_ERR(split)) return PTR_ERR(split); - btrfs_set_header_flags(split, btrfs_header_flags(c)); + root_add_used(root, root->nodesize); + + memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); btrfs_set_header_level(split, btrfs_header_level(c)); btrfs_set_header_bytenr(split, split->start); btrfs_set_header_generation(split, trans->transid); + btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); btrfs_set_header_owner(split, root->root_key.objectid); - btrfs_set_header_flags(split, 0); 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); - mid = (c_nritems + 1) / 2; - + 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), @@ -2266,15 +3539,8 @@ static noinline int split_node(struct btrfs_trans_handle *trans, btrfs_mark_buffer_dirty(c); btrfs_mark_buffer_dirty(split); - btrfs_node_key(split, &disk_key, 0); - wret = insert_ptr(trans, root, path, &disk_key, split->start, - path->slots[level + 1] + 1, - level + 1); - if (wret) - ret = wret; - - ret = btrfs_update_ref(trans, root, c, split, 0, c_nritems - mid); - BUG_ON(ret); + insert_ptr(trans, root, path, &disk_key, split->start, + path->slots[level + 1] + 1, level + 1); if (path->slots[level] >= mid) { path->slots[level] -= mid; @@ -2296,14 +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; @@ -2321,8 +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); } @@ -2330,76 +3603,45 @@ noinline int btrfs_leaf_free_space(struct btrfs_root *root, } /* - * push some data in the path leaf to the right, trying to free up at - * least data_size bytes. returns zero if the push worked, nonzero otherwise - * - * returns 1 if the push failed because the other node didn't have enough - * room, 0 if everything worked out and < 0 if there were major errors. + * min slot controls the lowest index we're willing to push to the + * right. We'll push up to and including min_slot, but no lower */ -static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root - *root, struct btrfs_path *path, int data_size, - int empty) +static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + int data_size, int empty, + struct extent_buffer *right, + int free_space, u32 left_nritems, + u32 min_slot) { struct extent_buffer *left = path->nodes[0]; - struct extent_buffer *right; - struct extent_buffer *upper; + struct extent_buffer *upper = path->nodes[1]; + struct btrfs_map_token token; struct btrfs_disk_key disk_key; int slot; u32 i; - int free_space; int push_space = 0; int push_items = 0; struct btrfs_item *item; - u32 left_nritems; u32 nr; u32 right_nritems; u32 data_end; u32 this_item_size; - int ret; - slot = path->slots[1]; - if (!path->nodes[1]) - return 1; - - upper = path->nodes[1]; - if (slot >= btrfs_header_nritems(upper) - 1) - return 1; - - btrfs_assert_tree_locked(path->nodes[1]); - - right = read_node_slot(root, upper, slot + 1); - btrfs_tree_lock(right); - btrfs_set_lock_blocking(right); - - free_space = btrfs_leaf_free_space(root, right); - if (free_space < data_size) - goto out_unlock; - - /* cow and double check */ - ret = btrfs_cow_block(trans, root, right, upper, - slot + 1, &right, 0); - if (ret) - goto out_unlock; - - free_space = btrfs_leaf_free_space(root, right); - if (free_space < data_size) - goto out_unlock; - - left_nritems = btrfs_header_nritems(left); - if (left_nritems == 0) - goto out_unlock; + btrfs_init_map_token(&token); if (empty) nr = 0; else - nr = 1; + nr = max_t(u32, 1, min_slot); if (path->slots[0] >= left_nritems) push_space += data_size; + 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) @@ -2414,14 +3656,6 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root if (path->slots[0] == i) push_space += data_size; - if (!left->map_token) { - map_extent_buffer(left, (unsigned long)item, - sizeof(struct btrfs_item), - &left->map_token, &left->kaddr, - &left->map_start, &left->map_len, - KM_USER1); - } - this_item_size = btrfs_item_size(left, item); if (this_item_size + sizeof(*item) + push_space > free_space) break; @@ -2432,16 +3666,11 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root break; i--; } - if (left->map_token) { - unmap_extent_buffer(left, left->map_token, KM_USER1); - left->map_token = NULL; - } 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); @@ -2476,31 +3705,20 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root 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); - if (!right->map_token) { - map_extent_buffer(right, (unsigned long)item, - sizeof(struct btrfs_item), - &right->map_token, &right->kaddr, - &right->map_start, &right->map_len, - KM_USER1); - } - push_space -= btrfs_item_size(right, item); - btrfs_set_item_offset(right, item, push_space); + item = btrfs_item_nr(i); + push_space -= btrfs_token_item_size(right, item, &token); + btrfs_set_token_item_offset(right, item, push_space, &token); } - if (right->map_token) { - unmap_extent_buffer(right, right->map_token, KM_USER1); - right->map_token = NULL; - } left_nritems -= push_items; btrfs_set_header_nritems(left, left_nritems); if (left_nritems) btrfs_mark_buffer_dirty(left); - btrfs_mark_buffer_dirty(right); + else + clean_tree_block(trans, root, left); - ret = btrfs_update_ref(trans, root, left, right, 0, push_items); - BUG_ON(ret); + btrfs_mark_buffer_dirty(right); btrfs_item_key(right, &disk_key, 0); btrfs_set_node_key(upper, &disk_key, slot + 1); @@ -2528,81 +3746,121 @@ out_unlock: } /* - * push some data in the path leaf to the left, trying to free up at + * push some data in the path leaf to the right, trying to free up at * least data_size bytes. returns zero if the push worked, nonzero otherwise + * + * returns 1 if the push failed because the other node didn't have enough + * room, 0 if everything worked out and < 0 if there were major errors. + * + * this will push starting from min_slot to the end of the leaf. It won't + * push any slot lower than min_slot */ -static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root - *root, struct btrfs_path *path, int data_size, - int empty) +static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root + *root, struct btrfs_path *path, + int min_data_size, int data_size, + int empty, u32 min_slot) { - struct btrfs_disk_key disk_key; - struct extent_buffer *right = path->nodes[0]; - struct extent_buffer *left; + struct extent_buffer *left = path->nodes[0]; + struct extent_buffer *right; + struct extent_buffer *upper; int slot; - int i; int free_space; - int push_space = 0; - int push_items = 0; - struct btrfs_item *item; - u32 old_left_nritems; - u32 right_nritems; - u32 nr; - int ret = 0; - int wret; - u32 this_item_size; - u32 old_left_item_size; + u32 left_nritems; + int ret; - slot = path->slots[1]; - if (slot == 0) - return 1; if (!path->nodes[1]) return 1; - right_nritems = btrfs_header_nritems(right); - if (right_nritems == 0) + slot = path->slots[1]; + upper = path->nodes[1]; + if (slot >= btrfs_header_nritems(upper) - 1) return 1; btrfs_assert_tree_locked(path->nodes[1]); - left = read_node_slot(root, path->nodes[1], slot - 1); - btrfs_tree_lock(left); - btrfs_set_lock_blocking(left); + right = read_node_slot(root, upper, slot + 1); + if (right == NULL) + return 1; - free_space = btrfs_leaf_free_space(root, left); - if (free_space < data_size) { - ret = 1; - goto out; - } + btrfs_tree_lock(right); + btrfs_set_lock_blocking(right); + + free_space = btrfs_leaf_free_space(root, right); + if (free_space < data_size) + goto out_unlock; /* cow and double check */ - ret = btrfs_cow_block(trans, root, left, - path->nodes[1], slot - 1, &left, 0); - if (ret) { - /* we hit -ENOSPC, but it isn't fatal here */ - ret = 1; - goto out; - } + ret = btrfs_cow_block(trans, root, right, upper, + slot + 1, &right); + if (ret) + goto out_unlock; - free_space = btrfs_leaf_free_space(root, left); - if (free_space < data_size) { - ret = 1; - goto out; + free_space = btrfs_leaf_free_space(root, right); + if (free_space < data_size) + goto out_unlock; + + left_nritems = btrfs_header_nritems(left); + 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: + btrfs_tree_unlock(right); + free_extent_buffer(right); + return 1; +} + +/* + * push some data in the path leaf to the left, trying to free up at + * least data_size bytes. returns zero if the push worked, nonzero otherwise + * + * max_slot can put a limit on how far into the leaf we'll push items. The + * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the + * items + */ +static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, int data_size, + int empty, struct extent_buffer *left, + int free_space, u32 right_nritems, + u32 max_slot) +{ + struct btrfs_disk_key disk_key; + struct extent_buffer *right = path->nodes[0]; + int i; + int push_space = 0; + int push_items = 0; + struct btrfs_item *item; + u32 old_left_nritems; + u32 nr; + int ret = 0; + u32 this_item_size; + u32 old_left_item_size; + struct btrfs_map_token token; + + btrfs_init_map_token(&token); + if (empty) - nr = right_nritems; + nr = min(right_nritems, max_slot); else - nr = right_nritems - 1; + nr = min(right_nritems - 1, max_slot); for (i = 0; i < nr; i++) { - item = btrfs_item_nr(right, i); - if (!right->map_token) { - map_extent_buffer(right, (unsigned long)item, - sizeof(struct btrfs_item), - &right->map_token, &right->kaddr, - &right->map_start, &right->map_len, - KM_USER1); - } + item = btrfs_item_nr(i); if (!empty && push_items > 0) { if (path->slots[0] < i) @@ -2625,17 +3883,11 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root push_space += this_item_size + sizeof(*item); } - if (right->map_token) { - unmap_extent_buffer(right, right->map_token, KM_USER1); - right->map_token = NULL; - } - if (push_items == 0) { 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, @@ -2658,31 +3910,19 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { u32 ioff; - item = btrfs_item_nr(left, i); - if (!left->map_token) { - map_extent_buffer(left, (unsigned long)item, - sizeof(struct btrfs_item), - &left->map_token, &left->kaddr, - &left->map_start, &left->map_len, - KM_USER1); - } + item = btrfs_item_nr(i); - ioff = btrfs_item_offset(left, item); - btrfs_set_item_offset(left, item, - ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size)); + ioff = btrfs_token_item_offset(left, item, &token); + btrfs_set_token_item_offset(left, item, + ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size), + &token); } btrfs_set_header_nritems(left, old_left_nritems + push_items); - if (left->map_token) { - unmap_extent_buffer(left, left->map_token, KM_USER1); - left->map_token = NULL; - } /* 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) - @@ -2701,42 +3941,25 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root 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); - - if (!right->map_token) { - map_extent_buffer(right, (unsigned long)item, - sizeof(struct btrfs_item), - &right->map_token, &right->kaddr, - &right->map_start, &right->map_len, - KM_USER1); - } + item = btrfs_item_nr(i); - push_space = push_space - btrfs_item_size(right, item); - btrfs_set_item_offset(right, item, push_space); - } - if (right->map_token) { - unmap_extent_buffer(right, right->map_token, KM_USER1); - right->map_token = NULL; + push_space = push_space - btrfs_token_item_size(right, + item, &token); + btrfs_set_token_item_offset(right, item, push_space, &token); } btrfs_mark_buffer_dirty(left); if (right_nritems) btrfs_mark_buffer_dirty(right); - - ret = btrfs_update_ref(trans, root, right, left, - old_left_nritems, push_items); - BUG_ON(ret); + else + clean_tree_block(trans, root, right); btrfs_item_key(right, &disk_key, 0); - wret = fixup_low_keys(trans, root, path, &disk_key, 1); - if (wret) - ret = wret; + fixup_low_keys(root, path, &disk_key, 1); /* then fixup the leaf pointer in the path */ if (path->slots[0] < push_items) { path->slots[0] += old_left_nritems; - if (btrfs_header_nritems(path->nodes[0]) == 0) - clean_tree_block(trans, root, path->nodes[0]); btrfs_tree_unlock(path->nodes[0]); free_extent_buffer(path->nodes[0]); path->nodes[0] = left; @@ -2755,6 +3978,203 @@ out: } /* + * push some data in the path leaf to the left, trying to free up at + * least data_size bytes. returns zero if the push worked, nonzero otherwise + * + * max_slot can put a limit on how far into the leaf we'll push items. The + * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the + * items + */ +static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root + *root, struct btrfs_path *path, int min_data_size, + int data_size, int empty, u32 max_slot) +{ + struct extent_buffer *right = path->nodes[0]; + struct extent_buffer *left; + int slot; + int free_space; + u32 right_nritems; + int ret = 0; + + slot = path->slots[1]; + if (slot == 0) + return 1; + if (!path->nodes[1]) + return 1; + + right_nritems = btrfs_header_nritems(right); + if (right_nritems == 0) + return 1; + + btrfs_assert_tree_locked(path->nodes[1]); + + left = read_node_slot(root, path->nodes[1], slot - 1); + if (left == NULL) + return 1; + + btrfs_tree_lock(left); + btrfs_set_lock_blocking(left); + + free_space = btrfs_leaf_free_space(root, left); + if (free_space < data_size) { + ret = 1; + goto out; + } + + /* cow and double check */ + ret = btrfs_cow_block(trans, root, left, + path->nodes[1], slot - 1, &left); + if (ret) { + /* we hit -ENOSPC, but it isn't fatal here */ + if (ret == -ENOSPC) + ret = 1; + goto out; + } + + free_space = btrfs_leaf_free_space(root, left); + if (free_space < data_size) { + ret = 1; + goto out; + } + + return __push_leaf_left(trans, root, path, min_data_size, + empty, left, free_space, right_nritems, + max_slot); +out: + btrfs_tree_unlock(left); + free_extent_buffer(left); + return ret; +} + +/* + * split the path's leaf in two, making sure there is at least data_size + * available for the resulting leaf level of the path. + */ +static noinline void copy_for_split(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct extent_buffer *l, + struct extent_buffer *right, + int slot, int mid, int nritems) +{ + int data_copy_size; + int rt_data_off; + int i; + struct btrfs_disk_key disk_key; + struct btrfs_map_token token; + + btrfs_init_map_token(&token); + + nritems = nritems - mid; + btrfs_set_header_nritems(right, nritems); + data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); + + copy_extent_buffer(right, l, btrfs_item_nr_offset(0), + btrfs_item_nr_offset(mid), + nritems * sizeof(struct btrfs_item)); + + copy_extent_buffer(right, l, + btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - + data_copy_size, btrfs_leaf_data(l) + + leaf_data_end(root, l), data_copy_size); + + rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - + btrfs_item_end_nr(l, mid); + + for (i = 0; i < nritems; i++) { + struct btrfs_item *item = btrfs_item_nr(i); + u32 ioff; + + ioff = btrfs_token_item_offset(right, item, &token); + btrfs_set_token_item_offset(right, item, + ioff + rt_data_off, &token); + } + + btrfs_set_header_nritems(l, mid); + btrfs_item_key(right, &disk_key, 0); + insert_ptr(trans, root, path, &disk_key, right->start, + path->slots[1] + 1, 1); + + btrfs_mark_buffer_dirty(right); + btrfs_mark_buffer_dirty(l); + BUG_ON(path->slots[0] != slot); + + if (mid <= slot) { + btrfs_tree_unlock(path->nodes[0]); + free_extent_buffer(path->nodes[0]); + path->nodes[0] = right; + path->slots[0] -= mid; + path->slots[1] += 1; + } else { + btrfs_tree_unlock(right); + free_extent_buffer(right); + } + + BUG_ON(path->slots[0] < 0); +} + +/* + * double splits happen when we need to insert a big item in the middle + * of a leaf. A double split can leave us with 3 mostly empty leaves: + * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] + * A B C + * + * We avoid this by trying to push the items on either side of our target + * into the adjacent leaves. If all goes well we can avoid the double split + * completely. + */ +static noinline int push_for_double_split(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + int data_size) +{ + int ret; + 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, space_needed, 0, slot); + if (ret < 0) + return ret; + + if (ret == 0) + progress++; + + nritems = btrfs_header_nritems(path->nodes[0]); + /* + * our goal is to get our slot at the start or end of a leaf. If + * we've done so we're done + */ + if (path->slots[0] == 0 || path->slots[0] == nritems) + return 0; + + if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) + return 0; + + /* 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, space_needed, 0, slot); + if (ret < 0) + return ret; + + if (ret == 0) + progress++; + + if (progress) + return 0; + return 1; +} + +/* * split the path's leaf in two, making sure there is at least data_size * available for the resulting leaf level of the path. * @@ -2766,27 +4186,38 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_path *path, int data_size, int extend) { + struct btrfs_disk_key disk_key; struct extent_buffer *l; u32 nritems; int mid; int slot; struct extent_buffer *right; - int data_copy_size; - int rt_data_off; - int i; int ret = 0; int wret; - int double_split; + int split; int num_doubles = 0; - struct btrfs_disk_key disk_key; + int tried_avoid_double = 0; + + l = path->nodes[0]; + slot = path->slots[0]; + if (extend && data_size + btrfs_item_size_nr(l, slot) + + sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) + return -EOVERFLOW; /* first try to make some room by pushing left and right */ - if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) { - wret = push_leaf_right(trans, root, path, data_size, 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, 0); + wret = push_leaf_left(trans, root, path, space_needed, + space_needed, 0, (u32)-1); if (wret < 0) return wret; } @@ -2803,85 +4234,34 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans, return ret; } again: - double_split = 0; + split = 1; l = path->nodes[0]; slot = path->slots[0]; nritems = btrfs_header_nritems(l); mid = (nritems + 1) / 2; - right = btrfs_alloc_free_block(trans, root, root->leafsize, - path->nodes[1]->start, - root->root_key.objectid, - trans->transid, 0, l->start, 0); - if (IS_ERR(right)) { - BUG_ON(1); - return PTR_ERR(right); - } - - memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); - btrfs_set_header_bytenr(right, right->start); - btrfs_set_header_generation(right, trans->transid); - 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); - - write_extent_buffer(right, root->fs_info->chunk_tree_uuid, - (unsigned long)btrfs_header_chunk_tree_uuid(right), - BTRFS_UUID_SIZE); if (mid <= slot) { if (nritems == 1 || leaf_space_used(l, mid, nritems - mid) + data_size > BTRFS_LEAF_DATA_SIZE(root)) { if (slot >= nritems) { - btrfs_cpu_key_to_disk(&disk_key, ins_key); - btrfs_set_header_nritems(right, 0); - wret = insert_ptr(trans, root, path, - &disk_key, right->start, - path->slots[1] + 1, 1); - if (wret) - ret = wret; - - btrfs_tree_unlock(path->nodes[0]); - free_extent_buffer(path->nodes[0]); - path->nodes[0] = right; - path->slots[0] = 0; - path->slots[1] += 1; - btrfs_mark_buffer_dirty(right); - return ret; - } - mid = slot; - if (mid != nritems && - leaf_space_used(l, mid, nritems - mid) + - data_size > BTRFS_LEAF_DATA_SIZE(root)) { - double_split = 1; + split = 0; + } else { + mid = slot; + if (mid != nritems && + leaf_space_used(l, mid, nritems - mid) + + data_size > BTRFS_LEAF_DATA_SIZE(root)) { + if (data_size && !tried_avoid_double) + goto push_for_double; + split = 2; + } } } } else { if (leaf_space_used(l, 0, mid) + data_size > BTRFS_LEAF_DATA_SIZE(root)) { if (!extend && data_size && slot == 0) { - btrfs_cpu_key_to_disk(&disk_key, ins_key); - btrfs_set_header_nritems(right, 0); - wret = insert_ptr(trans, root, path, - &disk_key, - right->start, - path->slots[1], 1); - if (wret) - ret = wret; - btrfs_tree_unlock(path->nodes[0]); - free_extent_buffer(path->nodes[0]); - path->nodes[0] = right; - path->slots[0] = 0; - if (path->slots[1] == 0) { - wret = fixup_low_keys(trans, root, - path, &disk_key, 1); - if (wret) - ret = wret; - } - btrfs_mark_buffer_dirty(right); - return ret; + split = 0; } else if ((extend || !data_size) && slot == 0) { mid = 1; } else { @@ -2889,178 +4269,193 @@ again: if (mid != nritems && leaf_space_used(l, mid, nritems - mid) + data_size > BTRFS_LEAF_DATA_SIZE(root)) { - double_split = 1; + if (data_size && !tried_avoid_double) + goto push_for_double; + split = 2; } } } } - nritems = nritems - mid; - btrfs_set_header_nritems(right, nritems); - data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); - copy_extent_buffer(right, l, btrfs_item_nr_offset(0), - btrfs_item_nr_offset(mid), - nritems * sizeof(struct btrfs_item)); - - copy_extent_buffer(right, l, - btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - - data_copy_size, btrfs_leaf_data(l) + - leaf_data_end(root, l), data_copy_size); - - rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - - btrfs_item_end_nr(l, mid); - - for (i = 0; i < nritems; i++) { - struct btrfs_item *item = btrfs_item_nr(right, i); - u32 ioff; - - if (!right->map_token) { - map_extent_buffer(right, (unsigned long)item, - sizeof(struct btrfs_item), - &right->map_token, &right->kaddr, - &right->map_start, &right->map_len, - KM_USER1); - } - - ioff = btrfs_item_offset(right, item); - btrfs_set_item_offset(right, item, ioff + rt_data_off); - } + if (split == 0) + btrfs_cpu_key_to_disk(&disk_key, ins_key); + else + btrfs_item_key(l, &disk_key, mid); - if (right->map_token) { - unmap_extent_buffer(right, right->map_token, KM_USER1); - right->map_token = NULL; - } + right = btrfs_alloc_free_block(trans, root, root->leafsize, 0, + root->root_key.objectid, + &disk_key, 0, l->start, 0); + if (IS_ERR(right)) + return PTR_ERR(right); - btrfs_set_header_nritems(l, mid); - ret = 0; - btrfs_item_key(right, &disk_key, 0); - wret = insert_ptr(trans, root, path, &disk_key, right->start, - path->slots[1] + 1, 1); - if (wret) - ret = wret; + root_add_used(root, root->leafsize); - btrfs_mark_buffer_dirty(right); - btrfs_mark_buffer_dirty(l); - BUG_ON(path->slots[0] != slot); + memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); + btrfs_set_header_bytenr(right, right->start); + btrfs_set_header_generation(right, trans->transid); + btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); + btrfs_set_header_owner(right, root->root_key.objectid); + btrfs_set_header_level(right, 0); + write_extent_buffer(right, root->fs_info->fsid, + btrfs_header_fsid(), BTRFS_FSID_SIZE); - ret = btrfs_update_ref(trans, root, l, right, 0, nritems); - BUG_ON(ret); + write_extent_buffer(right, root->fs_info->chunk_tree_uuid, + btrfs_header_chunk_tree_uuid(right), + BTRFS_UUID_SIZE); - if (mid <= slot) { - btrfs_tree_unlock(path->nodes[0]); - free_extent_buffer(path->nodes[0]); - path->nodes[0] = right; - path->slots[0] -= mid; - path->slots[1] += 1; - } else { - btrfs_tree_unlock(right); - free_extent_buffer(right); + if (split == 0) { + if (mid <= slot) { + btrfs_set_header_nritems(right, 0); + insert_ptr(trans, root, path, &disk_key, right->start, + path->slots[1] + 1, 1); + btrfs_tree_unlock(path->nodes[0]); + free_extent_buffer(path->nodes[0]); + path->nodes[0] = right; + path->slots[0] = 0; + path->slots[1] += 1; + } else { + btrfs_set_header_nritems(right, 0); + insert_ptr(trans, root, path, &disk_key, right->start, + path->slots[1], 1); + btrfs_tree_unlock(path->nodes[0]); + free_extent_buffer(path->nodes[0]); + path->nodes[0] = right; + path->slots[0] = 0; + if (path->slots[1] == 0) + fixup_low_keys(root, path, &disk_key, 1); + } + btrfs_mark_buffer_dirty(right); + return ret; } - BUG_ON(path->slots[0] < 0); + copy_for_split(trans, root, path, l, right, slot, mid, nritems); - if (double_split) { + if (split == 2) { BUG_ON(num_doubles != 0); num_doubles++; goto again; } - return ret; + + return 0; + +push_for_double: + push_for_double_split(trans, root, path, data_size); + tried_avoid_double = 1; + if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) + return 0; + goto again; } -/* - * This function splits a single item into two items, - * giving 'new_key' to the new item and splitting the - * old one at split_offset (from the start of the item). - * - * The path may be released by this operation. After - * the split, the path is pointing to the old item. The - * new item is going to be in the same node as the old one. - * - * Note, the item being split must be smaller enough to live alone on - * a tree block with room for one extra struct btrfs_item - * - * This allows us to split the item in place, keeping a lock on the - * leaf the entire time. - */ -int btrfs_split_item(struct btrfs_trans_handle *trans, - struct btrfs_root *root, - struct btrfs_path *path, - struct btrfs_key *new_key, - unsigned long split_offset) +static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, int ins_len) { - u32 item_size; + struct btrfs_key key; struct extent_buffer *leaf; - struct btrfs_key orig_key; - struct btrfs_item *item; - struct btrfs_item *new_item; - int ret = 0; - int slot; - u32 nritems; - u32 orig_offset; - struct btrfs_disk_key disk_key; - char *buf; + struct btrfs_file_extent_item *fi; + u64 extent_len = 0; + u32 item_size; + int ret; leaf = path->nodes[0]; - btrfs_item_key_to_cpu(leaf, &orig_key, path->slots[0]); - if (btrfs_leaf_free_space(root, leaf) >= sizeof(struct btrfs_item)) - goto split; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + + BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && + key.type != BTRFS_EXTENT_CSUM_KEY); + + if (btrfs_leaf_free_space(root, leaf) >= ins_len) + return 0; item_size = btrfs_item_size_nr(leaf, path->slots[0]); - btrfs_release_path(root, path); + if (key.type == BTRFS_EXTENT_DATA_KEY) { + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + extent_len = btrfs_file_extent_num_bytes(leaf, fi); + } + btrfs_release_path(path); - path->search_for_split = 1; path->keep_locks = 1; - - ret = btrfs_search_slot(trans, root, &orig_key, path, 0, 1); + path->search_for_split = 1; + ret = btrfs_search_slot(trans, root, &key, path, 0, 1); path->search_for_split = 0; + if (ret < 0) + goto err; + ret = -EAGAIN; + leaf = path->nodes[0]; /* if our item isn't there or got smaller, return now */ - if (ret != 0 || item_size != btrfs_item_size_nr(path->nodes[0], - path->slots[0])) { - path->keep_locks = 0; - return -EAGAIN; + if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0])) + goto err; + + /* the leaf has changed, it now has room. return now */ + if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len) + goto err; + + if (key.type == BTRFS_EXTENT_DATA_KEY) { + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) + goto err; } - ret = split_leaf(trans, root, &orig_key, path, - sizeof(struct btrfs_item), 1); + btrfs_set_path_blocking(path); + ret = split_leaf(trans, root, &key, path, ins_len, 1); + if (ret) + goto err; + path->keep_locks = 0; - BUG_ON(ret); + btrfs_unlock_up_safe(path, 1); + return 0; +err: + path->keep_locks = 0; + return ret; +} - /* - * make sure any changes to the path from split_leaf leave it - * in a blocking state - */ - btrfs_set_path_blocking(path); +static noinline int split_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_key *new_key, + unsigned long split_offset) +{ + struct extent_buffer *leaf; + struct btrfs_item *item; + struct btrfs_item *new_item; + int slot; + char *buf; + u32 nritems; + u32 item_size; + u32 orig_offset; + struct btrfs_disk_key disk_key; leaf = path->nodes[0]; BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); -split: - item = btrfs_item_nr(leaf, path->slots[0]); + btrfs_set_path_blocking(path); + + item = btrfs_item_nr(path->slots[0]); orig_offset = btrfs_item_offset(leaf, item); item_size = btrfs_item_size(leaf, item); - buf = kmalloc(item_size, GFP_NOFS); + if (!buf) + return -ENOMEM; + read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, path->slots[0]), item_size); - slot = path->slots[0] + 1; - leaf = path->nodes[0]; + slot = path->slots[0] + 1; nritems = btrfs_header_nritems(leaf); - if (slot != nritems) { /* shift the items */ memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), - btrfs_item_nr_offset(slot), - (nritems - slot) * sizeof(struct btrfs_item)); - + btrfs_item_nr_offset(slot), + (nritems - slot) * sizeof(struct btrfs_item)); } 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); @@ -3082,29 +4477,88 @@ split: item_size - split_offset); btrfs_mark_buffer_dirty(leaf); - ret = 0; - if (btrfs_leaf_free_space(root, leaf) < 0) { - btrfs_print_leaf(root, leaf); - BUG(); - } + BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); kfree(buf); + return 0; +} + +/* + * This function splits a single item into two items, + * giving 'new_key' to the new item and splitting the + * old one at split_offset (from the start of the item). + * + * The path may be released by this operation. After + * the split, the path is pointing to the old item. The + * new item is going to be in the same node as the old one. + * + * Note, the item being split must be smaller enough to live alone on + * a tree block with room for one extra struct btrfs_item + * + * This allows us to split the item in place, keeping a lock on the + * leaf the entire time. + */ +int btrfs_split_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_key *new_key, + unsigned long split_offset) +{ + int ret; + ret = setup_leaf_for_split(trans, root, path, + sizeof(struct btrfs_item)); + if (ret) + return ret; + + ret = split_item(trans, root, path, new_key, split_offset); return ret; } /* + * This function duplicate a item, giving 'new_key' to the new item. + * It guarantees both items live in the same tree leaf and the new item + * is contiguous with the original item. + * + * This allows us to split file extent in place, keeping a lock on the + * leaf the entire time. + */ +int btrfs_duplicate_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_key *new_key) +{ + struct extent_buffer *leaf; + int ret; + u32 item_size; + + leaf = path->nodes[0]; + item_size = btrfs_item_size_nr(leaf, path->slots[0]); + ret = setup_leaf_for_split(trans, root, path, + item_size + sizeof(struct btrfs_item)); + if (ret) + return ret; + + path->slots[0]++; + setup_items_for_insert(root, path, new_key, &item_size, + item_size, item_size + + sizeof(struct btrfs_item), 1); + leaf = path->nodes[0]; + memcpy_extent_buffer(leaf, + btrfs_item_ptr_offset(leaf, path->slots[0]), + btrfs_item_ptr_offset(leaf, path->slots[0] - 1), + item_size); + return 0; +} + +/* * make the item pointed to by the path smaller. new_size indicates * how small to make it, and from_end tells us if we just chop bytes * off the end of the item or if we shift the item to chop bytes off * the front. */ -int btrfs_truncate_item(struct btrfs_trans_handle *trans, - struct btrfs_root *root, - struct btrfs_path *path, - u32 new_size, int from_end) +void btrfs_truncate_item(struct btrfs_root *root, struct btrfs_path *path, + u32 new_size, int from_end) { - int ret = 0; int slot; - int slot_orig; struct extent_buffer *leaf; struct btrfs_item *item; u32 nritems; @@ -3113,14 +4567,16 @@ int btrfs_truncate_item(struct btrfs_trans_handle *trans, unsigned int old_size; unsigned int size_diff; int i; + struct btrfs_map_token token; + + btrfs_init_map_token(&token); - slot_orig = path->slots[0]; leaf = path->nodes[0]; slot = path->slots[0]; old_size = btrfs_item_size_nr(leaf, slot); if (old_size == new_size) - return 0; + return; nritems = btrfs_header_nritems(leaf); data_end = leaf_data_end(root, leaf); @@ -3138,23 +4594,11 @@ int 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); - - if (!leaf->map_token) { - map_extent_buffer(leaf, (unsigned long)item, - sizeof(struct btrfs_item), - &leaf->map_token, &leaf->kaddr, - &leaf->map_start, &leaf->map_len, - KM_USER1); - } + item = btrfs_item_nr(i); - ioff = btrfs_item_offset(leaf, item); - btrfs_set_item_offset(leaf, item, ioff + size_diff); - } - - if (leaf->map_token) { - unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); - leaf->map_token = NULL; + ioff = btrfs_token_item_offset(leaf, item, &token); + btrfs_set_token_item_offset(leaf, item, + ioff + size_diff, &token); } /* shift the data */ @@ -3195,31 +4639,26 @@ int 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); - ret = 0; if (btrfs_leaf_free_space(root, leaf) < 0) { btrfs_print_leaf(root, leaf); BUG(); } - return ret; } /* - * 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. */ -int btrfs_extend_item(struct btrfs_trans_handle *trans, - struct btrfs_root *root, struct btrfs_path *path, - u32 data_size) +void btrfs_extend_item(struct btrfs_root *root, struct btrfs_path *path, + u32 data_size) { - int ret = 0; int slot; - int slot_orig; struct extent_buffer *leaf; struct btrfs_item *item; u32 nritems; @@ -3227,8 +4666,10 @@ int btrfs_extend_item(struct btrfs_trans_handle *trans, unsigned int old_data; unsigned int old_size; int i; + struct btrfs_map_token token; + + btrfs_init_map_token(&token); - slot_orig = path->slots[0]; leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); @@ -3244,7 +4685,7 @@ int 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); } @@ -3255,22 +4696,11 @@ int 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); - - if (!leaf->map_token) { - map_extent_buffer(leaf, (unsigned long)item, - sizeof(struct btrfs_item), - &leaf->map_token, &leaf->kaddr, - &leaf->map_start, &leaf->map_len, - KM_USER1); - } - ioff = btrfs_item_offset(leaf, item); - btrfs_set_item_offset(leaf, item, ioff - data_size); - } + item = btrfs_item_nr(i); - if (leaf->map_token) { - unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); - leaf->map_token = NULL; + ioff = btrfs_token_item_offset(leaf, item, &token); + btrfs_set_token_item_offset(leaf, item, + ioff - data_size, &token); } /* shift the data */ @@ -3280,94 +4710,55 @@ int 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); - ret = 0; if (btrfs_leaf_free_space(root, leaf) < 0) { btrfs_print_leaf(root, leaf); BUG(); } - return ret; } /* - * 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. + * 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 */ -int btrfs_insert_some_items(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, - int nr) + u32 total_data, u32 total_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 extent_buffer *leaf; + int slot; + struct btrfs_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; + btrfs_init_map_token(&token); leaf = path->nodes[0]; + slot = path->slots[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; + btrfs_print_leaf(root, leaf); + btrfs_crit(root->fs_info, "not enough freespace need %u have %d", + total_size, btrfs_leaf_free_space(root, leaf)); + BUG(); } - 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 (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", + btrfs_crit(root->fs_info, "slot %d old_data %d data_end %d", slot, old_data, data_end); BUG_ON(1); } @@ -3375,27 +4766,14 @@ int btrfs_insert_some_items(struct btrfs_trans_handle *trans, * item0..itemN ... dataN.offset..dataN.size .. data0.size */ /* first correct the data pointers */ - WARN_ON(leaf->map_token); for (i = slot; i < nritems; i++) { u32 ioff; - item = btrfs_item_nr(leaf, i); - if (!leaf->map_token) { - map_extent_buffer(leaf, (unsigned long)item, - sizeof(struct btrfs_item), - &leaf->map_token, &leaf->kaddr, - &leaf->map_start, &leaf->map_len, - KM_USER1); - } - - ioff = btrfs_item_offset(leaf, item); - btrfs_set_item_offset(leaf, item, ioff - total_data); - } - if (leaf->map_token) { - unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); - leaf->map_token = NULL; + item = btrfs_item_nr( 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), @@ -3406,42 +4784,32 @@ int btrfs_insert_some_items(struct btrfs_trans_handle *trans, 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_item_offset(leaf, item, data_end - data_size[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]; - btrfs_set_item_size(leaf, item, 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); - ret = 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); if (btrfs_leaf_free_space(root, leaf) < 0) { btrfs_print_leaf(root, leaf); BUG(); } -out: - if (!ret) - ret = nr; - return ret; } /* @@ -3454,17 +4822,11 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, struct btrfs_key *cpu_key, u32 *data_size, int nr) { - struct extent_buffer *leaf; - struct btrfs_item *item; int ret = 0; int slot; - int slot_orig; int i; - u32 nritems; u32 total_size = 0; u32 total_data = 0; - unsigned int data_end; - struct btrfs_disk_key disk_key; for (i = 0; i < nr; i++) total_data += data_size[i]; @@ -3474,95 +4836,14 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, if (ret == 0) return -EEXIST; if (ret < 0) - goto out; - - slot_orig = path->slots[0]; - 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) { - btrfs_print_leaf(root, leaf); - printk(KERN_CRIT "not enough freespace need %u have %d\n", - total_size, btrfs_leaf_free_space(root, leaf)); - BUG(); - } + return ret; slot = path->slots[0]; BUG_ON(slot < 0); - if (slot != nritems) { - unsigned int old_data = btrfs_item_end_nr(leaf, slot); - - 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 */ - WARN_ON(leaf->map_token); - for (i = slot; i < nritems; i++) { - u32 ioff; - - item = btrfs_item_nr(leaf, i); - if (!leaf->map_token) { - map_extent_buffer(leaf, (unsigned long)item, - sizeof(struct btrfs_item), - &leaf->map_token, &leaf->kaddr, - &leaf->map_start, &leaf->map_len, - KM_USER1); - } - - ioff = btrfs_item_offset(leaf, item); - btrfs_set_item_offset(leaf, item, ioff - total_data); - } - if (leaf->map_token) { - unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); - leaf->map_token = NULL; - } - - /* 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; - } - - /* 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_item_offset(leaf, item, data_end - data_size[i]); - data_end -= data_size[i]; - btrfs_set_item_size(leaf, item, data_size[i]); - } - 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); - ret = fixup_low_keys(trans, root, path, &disk_key, 1); - } - - if (btrfs_leaf_free_space(root, leaf) < 0) { - btrfs_print_leaf(root, leaf); - BUG(); - } -out: - btrfs_unlock_up_safe(path, 1); - return ret; + setup_items_for_insert(root, path, cpu_key, data_size, + total_data, total_size, nr); + return 0; } /* @@ -3579,7 +4860,8 @@ int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root unsigned long ptr; path = btrfs_alloc_path(); - BUG_ON(!path); + if (!path) + return -ENOMEM; ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); if (!ret) { leaf = path->nodes[0]; @@ -3597,22 +4879,29 @@ 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 int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, - struct btrfs_path *path, int level, int slot) +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; - int ret = 0; - int wret; + int ret; nritems = btrfs_header_nritems(parent); if (slot != nritems - 1) { + if (level) + tree_mod_log_eb_move(root->fs_info, parent, slot, + slot + 1, nritems - slot - 1); memmove_extent_buffer(parent, btrfs_node_key_ptr_offset(slot), btrfs_node_key_ptr_offset(slot + 1), sizeof(struct btrfs_key_ptr) * (nritems - slot - 1)); + } else if (level) { + ret = tree_mod_log_insert_key(root->fs_info, parent, slot, + MOD_LOG_KEY_REMOVE, GFP_NOFS); + BUG_ON(ret < 0); } + nritems--; btrfs_set_header_nritems(parent, nritems); if (nritems == 0 && parent == root->node) { @@ -3623,19 +4912,14 @@ static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_disk_key disk_key; btrfs_node_key(parent, &disk_key, 0); - wret = fixup_low_keys(trans, root, path, &disk_key, level + 1); - if (wret) - ret = wret; + fixup_low_keys(root, path, &disk_key, level + 1); } btrfs_mark_buffer_dirty(parent); - return ret; } /* * a helper function to delete the leaf pointed to by path->slots[1] and - * path->nodes[1]. bytenr is the node block pointer, but since the callers - * already know it, it is faster to have them pass it down than to - * read it out of the node again. + * path->nodes[1]. * * This deletes the pointer in path->nodes[1] and frees the leaf * block extent. zero is returned if it all worked out, < 0 otherwise. @@ -3643,18 +4927,13 @@ static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, * The path must have already been setup for deleting the leaf, including * all the proper balancing. path->nodes[1] must be locked. */ -noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, - struct btrfs_root *root, - struct btrfs_path *path, u64 bytenr) +static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct extent_buffer *leaf) { - int ret; - u64 root_gen = btrfs_header_generation(path->nodes[1]); - u64 parent_start = path->nodes[1]->start; - u64 parent_owner = btrfs_header_owner(path->nodes[1]); - - ret = del_ptr(trans, root, path, 1, path->slots[1]); - if (ret) - return ret; + WARN_ON(btrfs_header_generation(leaf) != trans->transid); + del_ptr(root, path, 1, path->slots[1]); /* * btrfs_free_extent is expensive, we want to make sure we @@ -3662,11 +4941,11 @@ noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, */ btrfs_unlock_up_safe(path, 0); - ret = btrfs_free_extent(trans, root, bytenr, - btrfs_level_size(root, 0), - parent_start, parent_owner, - root_gen, 0, 1); - return ret; + root_sub_used(root, leaf->len); + + extent_buffer_get(leaf); + btrfs_free_tree_block(trans, root, leaf, 0, 1); + free_extent_buffer_stale(leaf); } /* * delete the item at the leaf level in path. If that empties @@ -3683,6 +4962,9 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, int wret; int i; u32 nritems; + struct btrfs_map_token token; + + btrfs_init_map_token(&token); leaf = path->nodes[0]; last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); @@ -3703,21 +4985,10 @@ 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); - if (!leaf->map_token) { - map_extent_buffer(leaf, (unsigned long)item, - sizeof(struct btrfs_item), - &leaf->map_token, &leaf->kaddr, - &leaf->map_start, &leaf->map_len, - KM_USER1); - } - ioff = btrfs_item_offset(leaf, item); - btrfs_set_item_offset(leaf, item, ioff + dsize); - } - - if (leaf->map_token) { - unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); - leaf->map_token = NULL; + item = btrfs_item_nr(i); + ioff = btrfs_token_item_offset(leaf, item, &token); + btrfs_set_token_item_offset(leaf, item, + ioff + dsize, &token); } memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), @@ -3733,8 +5004,9 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, if (leaf == root->node) { btrfs_set_header_level(leaf, 0); } else { - ret = btrfs_del_leaf(trans, root, path, leaf->start); - BUG_ON(ret); + btrfs_set_path_blocking(path); + clean_tree_block(trans, root, leaf); + btrfs_del_leaf(trans, root, path, leaf); } } else { int used = leaf_space_used(leaf, 0, nritems); @@ -3742,14 +5014,11 @@ 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); - wret = fixup_low_keys(trans, root, path, - &disk_key, 1); - if (wret) - ret = wret; + fixup_low_keys(root, path, &disk_key, 1); } /* delete the leaf if it is mostly empty */ - if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) { + if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { /* push_leaf_left fixes the path. * make sure the path still points to our leaf * for possible call to del_ptr below @@ -3757,23 +5026,25 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, slot = path->slots[1]; extent_buffer_get(leaf); - wret = push_leaf_left(trans, root, path, 1, 1); + btrfs_set_path_blocking(path); + wret = push_leaf_left(trans, root, path, 1, 1, + 1, (u32)-1); if (wret < 0 && wret != -ENOSPC) ret = wret; if (path->nodes[0] == leaf && btrfs_header_nritems(leaf)) { - wret = push_leaf_right(trans, root, path, 1, 1); + wret = push_leaf_right(trans, root, path, 1, + 1, 1, 0); if (wret < 0 && wret != -ENOSPC) ret = wret; } if (btrfs_header_nritems(leaf) == 0) { path->slots[1] = slot; - ret = btrfs_del_leaf(trans, root, path, - leaf->start); - BUG_ON(ret); + btrfs_del_leaf(trans, root, path, leaf); free_extent_buffer(leaf); + ret = 0; } else { /* if we're still in the path, make sure * we're dirty. Otherwise, one of the @@ -3807,30 +5078,44 @@ 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(root, path); + btrfs_release_path(path); ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) 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 @@ -3850,8 +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; @@ -3864,11 +5148,11 @@ int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, WARN_ON(!path->keep_locks); again: - cur = btrfs_lock_root_node(root); + cur = btrfs_read_lock_root_node(root); level = btrfs_header_level(cur); WARN_ON(path->nodes[level]); path->nodes[level] = cur; - path->locks[level] = 1; + path->locks[level] = BTRFS_READ_LOCK; if (btrfs_header_generation(cur) < min_trans) { ret = 1; @@ -3891,43 +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)) { - free_extent_buffer(tmp); - break; - } - if (tmp) - free_extent_buffer(tmp); - slot++; + break; } find_next_key: /* @@ -3938,9 +5197,9 @@ 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(root, path); + btrfs_release_path(path); goto again; } else { goto out; @@ -3951,18 +5210,19 @@ find_next_key: path->slots[level] = slot; if (level == path->lowest_level) { ret = 0; - unlock_up(path, level, 1); + unlock_up(path, level, 1, 0, NULL); goto out; } btrfs_set_path_blocking(path); cur = read_node_slot(root, cur, slot); + BUG_ON(!cur); /* -ENOMEM */ - btrfs_tree_lock(cur); + btrfs_tree_read_lock(cur); - path->locks[level - 1] = 1; + path->locks[level - 1] = BTRFS_READ_LOCK; path->nodes[level - 1] = cur; - unlock_up(path, level, 1); - btrfs_clear_path_blocking(path, NULL); + unlock_up(path, level, 1, 0, NULL); + btrfs_clear_path_blocking(path, NULL, 0); } out: if (ret == 0) @@ -3971,11 +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 @@ -3984,10 +5595,8 @@ out: * calling this function. */ int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, - struct btrfs_key *key, int lowest_level, - int cache_only, u64 min_trans) + struct btrfs_key *key, int level, u64 min_trans) { - int level = lowest_level; int slot; struct extent_buffer *c; @@ -4000,29 +5609,45 @@ int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, c = path->nodes[level]; next: if (slot >= btrfs_header_nritems(c)) { - level++; - if (level == BTRFS_MAX_LEVEL) + int ret; + int orig_lowest; + struct btrfs_key cur_key; + if (level + 1 >= BTRFS_MAX_LEVEL || + !path->nodes[level + 1]) return 1; - continue; + + if (path->locks[level + 1]) { + level++; + continue; + } + + slot = btrfs_header_nritems(c) - 1; + if (level == 0) + btrfs_item_key_to_cpu(c, &cur_key, slot); + else + btrfs_node_key_to_cpu(c, &cur_key, slot); + + orig_lowest = path->lowest_level; + btrfs_release_path(path); + path->lowest_level = level; + ret = btrfs_search_slot(NULL, root, &cur_key, path, + 0, 0); + path->lowest_level = orig_lowest; + if (ret < 0) + return ret; + + c = path->nodes[level]; + slot = path->slots[level]; + if (ret == 0) + slot++; + goto 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)) { - slot++; - if (cur) - free_extent_buffer(cur); - goto next; - } - free_extent_buffer(cur); - } if (gen < min_trans) { slot++; goto next; @@ -4041,29 +5666,45 @@ next: */ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) { + return btrfs_next_old_leaf(root, path, 0); +} + +int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, + u64 time_seq) +{ int slot; - int level = 1; + int level; struct extent_buffer *c; - struct extent_buffer *next = NULL; + struct extent_buffer *next; struct btrfs_key key; u32 nritems; int ret; + int old_spinning = path->leave_spinning; + int next_rw_lock = 0; nritems = btrfs_header_nritems(path->nodes[0]); if (nritems == 0) return 1; btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); +again: + level = 1; + next = NULL; + next_rw_lock = 0; + btrfs_release_path(path); - btrfs_release_path(root, path); path->keep_locks = 1; - ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + path->leave_spinning = 1; + + if (time_seq) + ret = btrfs_search_old_slot(root, &key, path, time_seq); + else + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); path->keep_locks = 0; if (ret < 0) return ret; - btrfs_set_path_blocking(path); nritems = btrfs_header_nritems(path->nodes[0]); /* * by releasing the path above we dropped all our locks. A balance @@ -4072,38 +5713,86 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) * advance the path if there are now more items available. */ if (nritems > 0 && path->slots[0] < nritems - 1) { - path->slots[0]++; + if (ret == 0) + path->slots[0]++; + 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]) - return 1; + if (!path->nodes[level]) { + ret = 1; + goto done; + } slot = path->slots[level] + 1; c = path->nodes[level]; if (slot >= btrfs_header_nritems(c)) { level++; - if (level == BTRFS_MAX_LEVEL) - return 1; + if (level == BTRFS_MAX_LEVEL) { + ret = 1; + goto done; + } continue; } if (next) { - btrfs_tree_unlock(next); + btrfs_tree_unlock_rw(next, next_rw_lock); free_extent_buffer(next); } - /* the path was set to blocking above */ - if (level == 1 && (path->locks[1] || path->skip_locking) && - path->reada) - reada_for_search(root, path, level, slot, 0); + next = c; + next_rw_lock = path->locks[level]; + ret = read_block_for_search(NULL, root, path, &next, level, + slot, &key, 0); + if (ret == -EAGAIN) + goto again; + + if (ret < 0) { + btrfs_release_path(path); + goto done; + } - next = read_node_slot(root, c, slot); if (!path->skip_locking) { - btrfs_assert_tree_locked(c); - btrfs_tree_lock(next); - btrfs_set_lock_blocking(next); + ret = btrfs_try_tree_read_lock(next); + if (!ret && time_seq) { + /* + * If we don't get the lock, we may be racing + * with push_leaf_left, holding that lock while + * itself waiting for the leaf we've currently + * 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; + } + if (!ret) { + btrfs_set_path_blocking(path); + btrfs_tree_read_lock(next); + btrfs_clear_path_blocking(path, next, + BTRFS_READ_LOCK); + } + next_rw_lock = BTRFS_READ_LOCK; } break; } @@ -4112,28 +5801,45 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) level--; c = path->nodes[level]; if (path->locks[level]) - btrfs_tree_unlock(c); + btrfs_tree_unlock_rw(c, path->locks[level]); + free_extent_buffer(c); path->nodes[level] = next; path->slots[level] = 0; if (!path->skip_locking) - path->locks[level] = 1; + path->locks[level] = next_rw_lock; if (!level) break; - btrfs_set_path_blocking(path); - if (level == 1 && path->locks[1] && path->reada) - reada_for_search(root, path, level, slot, 0); - next = read_node_slot(root, next, 0); + ret = read_block_for_search(NULL, root, path, &next, level, + 0, &key, 0); + if (ret == -EAGAIN) + goto again; + + if (ret < 0) { + btrfs_release_path(path); + goto done; + } + if (!path->skip_locking) { - btrfs_assert_tree_locked(path->nodes[level]); - btrfs_tree_lock(next); - btrfs_set_lock_blocking(next); + ret = btrfs_try_tree_read_lock(next); + if (!ret) { + btrfs_set_path_blocking(path); + btrfs_tree_read_lock(next); + btrfs_clear_path_blocking(path, next, + BTRFS_READ_LOCK); + } + next_rw_lock = BTRFS_READ_LOCK; } } + ret = 0; done: - unlock_up(path, 0, 1); - return 0; + unlock_up(path, 0, 1, 0, NULL); + path->leave_spinning = old_spinning; + if (!old_spinning) + btrfs_set_path_blocking(path); + + return ret; } /* @@ -4168,12 +5874,55 @@ int btrfs_previous_item(struct btrfs_root *root, 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 == type) return 0; + if (found_key.objectid == min_objectid && + found_key.type < type) + break; + } + 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 < type) + found_key.type < BTRFS_EXTENT_ITEM_KEY) break; } return 1; |