179154b1bSChris Mason #include <linux/module.h> 279154b1bSChris Mason #include <linux/fs.h> 379154b1bSChris Mason #include "ctree.h" 479154b1bSChris Mason #include "disk-io.h" 579154b1bSChris Mason #include "transaction.h" 679154b1bSChris Mason 778fae27eSChris Mason static int total_trans = 0; 82c90e5d6SChris Mason extern struct kmem_cache *btrfs_trans_handle_cachep; 92c90e5d6SChris Mason extern struct kmem_cache *btrfs_transaction_cachep; 102c90e5d6SChris Mason 110f7d52f4SChris Mason #define BTRFS_ROOT_TRANS_TAG 0 120f7d52f4SChris Mason 132c90e5d6SChris Mason #define TRANS_MAGIC 0xE1E10E 1479154b1bSChris Mason static void put_transaction(struct btrfs_transaction *transaction) 1579154b1bSChris Mason { 162c90e5d6SChris Mason WARN_ON(transaction->use_count == 0); 1779154b1bSChris Mason transaction->use_count--; 182c90e5d6SChris Mason WARN_ON(transaction->magic != TRANS_MAGIC); 1978fae27eSChris Mason if (transaction->use_count == 0) { 2078fae27eSChris Mason WARN_ON(total_trans == 0); 2178fae27eSChris Mason total_trans--; 228fd17795SChris Mason list_del_init(&transaction->list); 232c90e5d6SChris Mason memset(transaction, 0, sizeof(*transaction)); 242c90e5d6SChris Mason kmem_cache_free(btrfs_transaction_cachep, transaction); 2579154b1bSChris Mason } 2678fae27eSChris Mason } 2779154b1bSChris Mason 2879154b1bSChris Mason static int join_transaction(struct btrfs_root *root) 2979154b1bSChris Mason { 3079154b1bSChris Mason struct btrfs_transaction *cur_trans; 3179154b1bSChris Mason cur_trans = root->fs_info->running_transaction; 3279154b1bSChris Mason if (!cur_trans) { 332c90e5d6SChris Mason cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, 342c90e5d6SChris Mason GFP_NOFS); 3578fae27eSChris Mason total_trans++; 3679154b1bSChris Mason BUG_ON(!cur_trans); 370f7d52f4SChris Mason root->fs_info->generation++; 3879154b1bSChris Mason root->fs_info->running_transaction = cur_trans; 3979154b1bSChris Mason cur_trans->num_writers = 0; 400f7d52f4SChris Mason cur_trans->transid = root->fs_info->generation; 4179154b1bSChris Mason init_waitqueue_head(&cur_trans->writer_wait); 4279154b1bSChris Mason init_waitqueue_head(&cur_trans->commit_wait); 432c90e5d6SChris Mason cur_trans->magic = TRANS_MAGIC; 4479154b1bSChris Mason cur_trans->in_commit = 0; 45d5719762SChris Mason cur_trans->use_count = 1; 4679154b1bSChris Mason cur_trans->commit_done = 0; 478fd17795SChris Mason list_add_tail(&cur_trans->list, &root->fs_info->trans_list); 487c4452b9SChris Mason init_bit_radix(&cur_trans->dirty_pages); 4979154b1bSChris Mason } 5079154b1bSChris Mason cur_trans->num_writers++; 5179154b1bSChris Mason return 0; 5279154b1bSChris Mason } 5379154b1bSChris Mason 5479154b1bSChris Mason struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, 5579154b1bSChris Mason int num_blocks) 5679154b1bSChris Mason { 572c90e5d6SChris Mason struct btrfs_trans_handle *h = 582c90e5d6SChris Mason kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS); 5979154b1bSChris Mason int ret; 600f7d52f4SChris Mason u64 running_trans_id; 6179154b1bSChris Mason 6279154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 6379154b1bSChris Mason ret = join_transaction(root); 6479154b1bSChris Mason BUG_ON(ret); 650f7d52f4SChris Mason running_trans_id = root->fs_info->running_transaction->transid; 660f7d52f4SChris Mason 670f7d52f4SChris Mason if (root != root->fs_info->tree_root && root->last_trans < 680f7d52f4SChris Mason running_trans_id) { 690f7d52f4SChris Mason radix_tree_tag_set(&root->fs_info->fs_roots_radix, 702619ba1fSChris Mason (unsigned long)root->root_key.objectid, 712619ba1fSChris Mason BTRFS_ROOT_TRANS_TAG); 720f7d52f4SChris Mason root->commit_root = root->node; 730f7d52f4SChris Mason get_bh(root->node); 740f7d52f4SChris Mason } 750f7d52f4SChris Mason root->last_trans = running_trans_id; 760f7d52f4SChris Mason h->transid = running_trans_id; 7779154b1bSChris Mason h->transaction = root->fs_info->running_transaction; 7879154b1bSChris Mason h->blocks_reserved = num_blocks; 7979154b1bSChris Mason h->blocks_used = 0; 8079154b1bSChris Mason root->fs_info->running_transaction->use_count++; 8179154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 822c90e5d6SChris Mason h->magic = h->magic2 = TRANS_MAGIC; 8379154b1bSChris Mason return h; 8479154b1bSChris Mason } 8579154b1bSChris Mason 8679154b1bSChris Mason int btrfs_end_transaction(struct btrfs_trans_handle *trans, 8779154b1bSChris Mason struct btrfs_root *root) 8879154b1bSChris Mason { 8979154b1bSChris Mason struct btrfs_transaction *cur_trans; 90d6e4a428SChris Mason 912c90e5d6SChris Mason WARN_ON(trans->magic != TRANS_MAGIC); 922c90e5d6SChris Mason WARN_ON(trans->magic2 != TRANS_MAGIC); 9379154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 9479154b1bSChris Mason cur_trans = root->fs_info->running_transaction; 95d5719762SChris Mason WARN_ON(cur_trans->num_writers < 1); 9679154b1bSChris Mason if (waitqueue_active(&cur_trans->writer_wait)) 9779154b1bSChris Mason wake_up(&cur_trans->writer_wait); 9879154b1bSChris Mason cur_trans->num_writers--; 9979154b1bSChris Mason put_transaction(cur_trans); 10079154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 101d6025579SChris Mason memset(trans, 0, sizeof(*trans)); 1022c90e5d6SChris Mason kmem_cache_free(btrfs_trans_handle_cachep, trans); 10379154b1bSChris Mason return 0; 10479154b1bSChris Mason } 10579154b1bSChris Mason 10679154b1bSChris Mason 10779154b1bSChris Mason int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans, 10879154b1bSChris Mason struct btrfs_root *root) 10979154b1bSChris Mason { 1107c4452b9SChris Mason unsigned long gang[16]; 1117c4452b9SChris Mason int ret; 1127c4452b9SChris Mason int i; 1137c4452b9SChris Mason int err; 1147c4452b9SChris Mason int werr = 0; 1157c4452b9SChris Mason struct page *page; 1167c4452b9SChris Mason struct radix_tree_root *dirty_pages; 1177c4452b9SChris Mason struct inode *btree_inode = root->fs_info->btree_inode; 1187c4452b9SChris Mason 1197c4452b9SChris Mason if (!trans || !trans->transaction) { 1207c4452b9SChris Mason return filemap_write_and_wait(btree_inode->i_mapping); 1217c4452b9SChris Mason } 1227c4452b9SChris Mason dirty_pages = &trans->transaction->dirty_pages; 1237c4452b9SChris Mason while(1) { 1247c4452b9SChris Mason ret = find_first_radix_bit(dirty_pages, gang, ARRAY_SIZE(gang)); 1257c4452b9SChris Mason if (!ret) 1267c4452b9SChris Mason break; 1277c4452b9SChris Mason for (i = 0; i < ret; i++) { 1287c4452b9SChris Mason /* FIXME EIO */ 1297c4452b9SChris Mason clear_radix_bit(dirty_pages, gang[i]); 1307c4452b9SChris Mason page = find_lock_page(btree_inode->i_mapping, 1317c4452b9SChris Mason gang[i]); 1327c4452b9SChris Mason if (!page) 1337c4452b9SChris Mason continue; 1347c4452b9SChris Mason err = write_one_page(page, 0); 1357c4452b9SChris Mason if (err) 1367c4452b9SChris Mason werr = err; 1377c4452b9SChris Mason page_cache_release(page); 1387c4452b9SChris Mason } 1397c4452b9SChris Mason } 1407c4452b9SChris Mason err = filemap_fdatawait(btree_inode->i_mapping); 1417c4452b9SChris Mason if (err) 1427c4452b9SChris Mason werr = err; 1437c4452b9SChris Mason return werr; 14479154b1bSChris Mason } 14579154b1bSChris Mason 14679154b1bSChris Mason int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans, 14779154b1bSChris Mason struct btrfs_root *root) 14879154b1bSChris Mason { 14979154b1bSChris Mason int ret; 15079154b1bSChris Mason u64 old_extent_block; 15179154b1bSChris Mason struct btrfs_fs_info *fs_info = root->fs_info; 15279154b1bSChris Mason struct btrfs_root *tree_root = fs_info->tree_root; 15379154b1bSChris Mason struct btrfs_root *extent_root = fs_info->extent_root; 1548352d8a4SChris Mason struct btrfs_root *dev_root = fs_info->dev_root; 15579154b1bSChris Mason 1568352d8a4SChris Mason if (btrfs_super_device_root(fs_info->disk_super) != 1578352d8a4SChris Mason bh_blocknr(dev_root->node)) { 1588352d8a4SChris Mason btrfs_set_super_device_root(fs_info->disk_super, 1598352d8a4SChris Mason bh_blocknr(dev_root->node)); 1608352d8a4SChris Mason } 1619078a3e1SChris Mason btrfs_write_dirty_block_groups(trans, extent_root); 16279154b1bSChris Mason while(1) { 16379154b1bSChris Mason old_extent_block = btrfs_root_blocknr(&extent_root->root_item); 1647eccb903SChris Mason if (old_extent_block == bh_blocknr(extent_root->node)) 16579154b1bSChris Mason break; 16679154b1bSChris Mason btrfs_set_root_blocknr(&extent_root->root_item, 1677eccb903SChris Mason bh_blocknr(extent_root->node)); 16879154b1bSChris Mason ret = btrfs_update_root(trans, tree_root, 16979154b1bSChris Mason &extent_root->root_key, 17079154b1bSChris Mason &extent_root->root_item); 17179154b1bSChris Mason BUG_ON(ret); 1729078a3e1SChris Mason btrfs_write_dirty_block_groups(trans, extent_root); 17379154b1bSChris Mason } 17479154b1bSChris Mason return 0; 17579154b1bSChris Mason } 17679154b1bSChris Mason 17779154b1bSChris Mason static int wait_for_commit(struct btrfs_root *root, 17879154b1bSChris Mason struct btrfs_transaction *commit) 17979154b1bSChris Mason { 18079154b1bSChris Mason DEFINE_WAIT(wait); 18179154b1bSChris Mason while(!commit->commit_done) { 18279154b1bSChris Mason prepare_to_wait(&commit->commit_wait, &wait, 18379154b1bSChris Mason TASK_UNINTERRUPTIBLE); 18479154b1bSChris Mason if (commit->commit_done) 18579154b1bSChris Mason break; 18679154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 18779154b1bSChris Mason schedule(); 18879154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 18979154b1bSChris Mason } 19079154b1bSChris Mason finish_wait(&commit->commit_wait, &wait); 19179154b1bSChris Mason return 0; 19279154b1bSChris Mason } 19379154b1bSChris Mason 1940f7d52f4SChris Mason struct dirty_root { 1950f7d52f4SChris Mason struct list_head list; 1960f7d52f4SChris Mason struct btrfs_key snap_key; 1970f7d52f4SChris Mason struct buffer_head *commit_root; 1980f7d52f4SChris Mason struct btrfs_root *root; 1990f7d52f4SChris Mason }; 2000f7d52f4SChris Mason 2010f7d52f4SChris Mason int add_dirty_roots(struct btrfs_trans_handle *trans, 2020f7d52f4SChris Mason struct radix_tree_root *radix, struct list_head *list) 2030f7d52f4SChris Mason { 2040f7d52f4SChris Mason struct dirty_root *dirty; 2050f7d52f4SChris Mason struct btrfs_root *gang[8]; 2060f7d52f4SChris Mason struct btrfs_root *root; 2070f7d52f4SChris Mason int i; 2080f7d52f4SChris Mason int ret; 2090f7d52f4SChris Mason int err; 2100f7d52f4SChris Mason while(1) { 2110f7d52f4SChris Mason ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0, 2120f7d52f4SChris Mason ARRAY_SIZE(gang), 2130f7d52f4SChris Mason BTRFS_ROOT_TRANS_TAG); 2140f7d52f4SChris Mason if (ret == 0) 2150f7d52f4SChris Mason break; 2160f7d52f4SChris Mason for (i = 0; i < ret; i++) { 2170f7d52f4SChris Mason root = gang[i]; 2182619ba1fSChris Mason radix_tree_tag_clear(radix, 2192619ba1fSChris Mason (unsigned long)root->root_key.objectid, 2200f7d52f4SChris Mason BTRFS_ROOT_TRANS_TAG); 2210f7d52f4SChris Mason if (root->commit_root == root->node) { 2227eccb903SChris Mason WARN_ON(bh_blocknr(root->node) != 2230f7d52f4SChris Mason btrfs_root_blocknr(&root->root_item)); 2240f7d52f4SChris Mason brelse(root->commit_root); 2250f7d52f4SChris Mason root->commit_root = NULL; 2260f7d52f4SChris Mason continue; 2270f7d52f4SChris Mason } 2280f7d52f4SChris Mason dirty = kmalloc(sizeof(*dirty), GFP_NOFS); 2290f7d52f4SChris Mason BUG_ON(!dirty); 2300f7d52f4SChris Mason memcpy(&dirty->snap_key, &root->root_key, 2310f7d52f4SChris Mason sizeof(root->root_key)); 2320f7d52f4SChris Mason dirty->commit_root = root->commit_root; 2330f7d52f4SChris Mason root->commit_root = NULL; 2340f7d52f4SChris Mason dirty->root = root; 2350f7d52f4SChris Mason root->root_key.offset = root->fs_info->generation; 2360f7d52f4SChris Mason btrfs_set_root_blocknr(&root->root_item, 2377eccb903SChris Mason bh_blocknr(root->node)); 2380f7d52f4SChris Mason err = btrfs_insert_root(trans, root->fs_info->tree_root, 2390f7d52f4SChris Mason &root->root_key, 2400f7d52f4SChris Mason &root->root_item); 2410f7d52f4SChris Mason BUG_ON(err); 2420f7d52f4SChris Mason list_add(&dirty->list, list); 2430f7d52f4SChris Mason } 2440f7d52f4SChris Mason } 2450f7d52f4SChris Mason return 0; 2460f7d52f4SChris Mason } 2470f7d52f4SChris Mason 2480f7d52f4SChris Mason int drop_dirty_roots(struct btrfs_root *tree_root, struct list_head *list) 2490f7d52f4SChris Mason { 2500f7d52f4SChris Mason struct dirty_root *dirty; 2510f7d52f4SChris Mason struct btrfs_trans_handle *trans; 2520f7d52f4SChris Mason int ret; 2530f7d52f4SChris Mason 2540f7d52f4SChris Mason while(!list_empty(list)) { 2550f7d52f4SChris Mason dirty = list_entry(list->next, struct dirty_root, list); 2560f7d52f4SChris Mason list_del_init(&dirty->list); 2570f7d52f4SChris Mason trans = btrfs_start_transaction(tree_root, 1); 2580f7d52f4SChris Mason ret = btrfs_drop_snapshot(trans, dirty->root, 2590f7d52f4SChris Mason dirty->commit_root); 2600f7d52f4SChris Mason BUG_ON(ret); 2610f7d52f4SChris Mason 2620f7d52f4SChris Mason ret = btrfs_del_root(trans, tree_root, &dirty->snap_key); 2630f7d52f4SChris Mason BUG_ON(ret); 2640f7d52f4SChris Mason ret = btrfs_end_transaction(trans, tree_root); 2650f7d52f4SChris Mason BUG_ON(ret); 2660f7d52f4SChris Mason kfree(dirty); 2670f7d52f4SChris Mason } 2680f7d52f4SChris Mason return 0; 2690f7d52f4SChris Mason } 2700f7d52f4SChris Mason 27179154b1bSChris Mason int btrfs_commit_transaction(struct btrfs_trans_handle *trans, 27279154b1bSChris Mason struct btrfs_root *root) 27379154b1bSChris Mason { 27479154b1bSChris Mason int ret = 0; 27579154b1bSChris Mason struct btrfs_transaction *cur_trans; 2768fd17795SChris Mason struct btrfs_transaction *prev_trans = NULL; 2770f7d52f4SChris Mason struct list_head dirty_fs_roots; 27879154b1bSChris Mason DEFINE_WAIT(wait); 27979154b1bSChris Mason 2800f7d52f4SChris Mason INIT_LIST_HEAD(&dirty_fs_roots); 281d6e4a428SChris Mason 28279154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 28379154b1bSChris Mason if (trans->transaction->in_commit) { 28479154b1bSChris Mason cur_trans = trans->transaction; 28579154b1bSChris Mason trans->transaction->use_count++; 28679154b1bSChris Mason btrfs_end_transaction(trans, root); 28779154b1bSChris Mason ret = wait_for_commit(root, cur_trans); 28879154b1bSChris Mason BUG_ON(ret); 28979154b1bSChris Mason put_transaction(cur_trans); 29079154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 29179154b1bSChris Mason return 0; 29279154b1bSChris Mason } 2932c90e5d6SChris Mason cur_trans = trans->transaction; 2942c90e5d6SChris Mason trans->transaction->in_commit = 1; 29579154b1bSChris Mason while (trans->transaction->num_writers > 1) { 2962c90e5d6SChris Mason WARN_ON(cur_trans != trans->transaction); 29779154b1bSChris Mason prepare_to_wait(&trans->transaction->writer_wait, &wait, 29879154b1bSChris Mason TASK_UNINTERRUPTIBLE); 29979154b1bSChris Mason if (trans->transaction->num_writers <= 1) 30079154b1bSChris Mason break; 30179154b1bSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 30279154b1bSChris Mason schedule(); 30379154b1bSChris Mason mutex_lock(&root->fs_info->trans_mutex); 3042c90e5d6SChris Mason finish_wait(&trans->transaction->writer_wait, &wait); 30579154b1bSChris Mason } 30679154b1bSChris Mason finish_wait(&trans->transaction->writer_wait, &wait); 3072c90e5d6SChris Mason WARN_ON(cur_trans != trans->transaction); 3080f7d52f4SChris Mason add_dirty_roots(trans, &root->fs_info->fs_roots_radix, &dirty_fs_roots); 30979154b1bSChris Mason ret = btrfs_commit_tree_roots(trans, root); 31079154b1bSChris Mason BUG_ON(ret); 31178fae27eSChris Mason cur_trans = root->fs_info->running_transaction; 31278fae27eSChris Mason root->fs_info->running_transaction = NULL; 3138fd17795SChris Mason if (cur_trans->list.prev != &root->fs_info->trans_list) { 3148fd17795SChris Mason prev_trans = list_entry(cur_trans->list.prev, 3158fd17795SChris Mason struct btrfs_transaction, list); 3168fd17795SChris Mason if (prev_trans->commit_done) 3178fd17795SChris Mason prev_trans = NULL; 3188fd17795SChris Mason else 3198fd17795SChris Mason prev_trans->use_count++; 3208fd17795SChris Mason } 32178fae27eSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 3228fd17795SChris Mason mutex_unlock(&root->fs_info->fs_mutex); 32379154b1bSChris Mason ret = btrfs_write_and_wait_transaction(trans, root); 3248fd17795SChris Mason if (prev_trans) { 3258fd17795SChris Mason mutex_lock(&root->fs_info->trans_mutex); 3268fd17795SChris Mason wait_for_commit(root, prev_trans); 3278fd17795SChris Mason put_transaction(prev_trans); 3288fd17795SChris Mason mutex_unlock(&root->fs_info->trans_mutex); 3298fd17795SChris Mason } 3308fd17795SChris Mason btrfs_set_super_generation(root->fs_info->disk_super, 3318fd17795SChris Mason cur_trans->transid); 33279154b1bSChris Mason BUG_ON(ret); 33379154b1bSChris Mason write_ctree_super(trans, root); 3348fd17795SChris Mason 3358fd17795SChris Mason mutex_lock(&root->fs_info->fs_mutex); 33678fae27eSChris Mason btrfs_finish_extent_commit(trans, root); 33778fae27eSChris Mason mutex_lock(&root->fs_info->trans_mutex); 3382c90e5d6SChris Mason cur_trans->commit_done = 1; 3392c90e5d6SChris Mason wake_up(&cur_trans->commit_wait); 34079154b1bSChris Mason put_transaction(cur_trans); 34178fae27eSChris Mason put_transaction(cur_trans); 34278fae27eSChris Mason mutex_unlock(&root->fs_info->trans_mutex); 3432c90e5d6SChris Mason kmem_cache_free(btrfs_trans_handle_cachep, trans); 34479154b1bSChris Mason 3450f7d52f4SChris Mason drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots); 34679154b1bSChris Mason return ret; 34779154b1bSChris Mason } 34879154b1bSChris Mason 349