| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 2007 Oracle. All rights reserved. |
| */ |
| |
| #include <linux/fs.h> |
| #include <linux/slab.h> |
| #include <linux/sched.h> |
| #include <linux/writeback.h> |
| #include <linux/pagemap.h> |
| #include <linux/blkdev.h> |
| #include <linux/uuid.h> |
| #include "misc.h" |
| #include "ctree.h" |
| #include "disk-io.h" |
| #include "transaction.h" |
| #include "locking.h" |
| #include "tree-log.h" |
| #include "volumes.h" |
| #include "dev-replace.h" |
| #include "qgroup.h" |
| #include "block-group.h" |
| #include "space-info.h" |
| #include "zoned.h" |
| |
| #define BTRFS_ROOT_TRANS_TAG XA_MARK_0 |
| |
| /* |
| * Transaction states and transitions |
| * |
| * No running transaction (fs tree blocks are not modified) |
| * | |
| * | To next stage: |
| * | Call start_transaction() variants. Except btrfs_join_transaction_nostart(). |
| * V |
| * Transaction N [[TRANS_STATE_RUNNING]] |
| * | |
| * | New trans handles can be attached to transaction N by calling all |
| * | start_transaction() variants. |
| * | |
| * | To next stage: |
| * | Call btrfs_commit_transaction() on any trans handle attached to |
| * | transaction N |
| * V |
| * Transaction N [[TRANS_STATE_COMMIT_START]] |
| * | |
| * | Will wait for previous running transaction to completely finish if there |
| * | is one |
| * | |
| * | Then one of the following happes: |
| * | - Wait for all other trans handle holders to release. |
| * | The btrfs_commit_transaction() caller will do the commit work. |
| * | - Wait for current transaction to be committed by others. |
| * | Other btrfs_commit_transaction() caller will do the commit work. |
| * | |
| * | At this stage, only btrfs_join_transaction*() variants can attach |
| * | to this running transaction. |
| * | All other variants will wait for current one to finish and attach to |
| * | transaction N+1. |
| * | |
| * | To next stage: |
| * | Caller is chosen to commit transaction N, and all other trans handle |
| * | haven been released. |
| * V |
| * Transaction N [[TRANS_STATE_COMMIT_DOING]] |
| * | |
| * | The heavy lifting transaction work is started. |
| * | From running delayed refs (modifying extent tree) to creating pending |
| * | snapshots, running qgroups. |
| * | In short, modify supporting trees to reflect modifications of subvolume |
| * | trees. |
| * | |
| * | At this stage, all start_transaction() calls will wait for this |
| * | transaction to finish and attach to transaction N+1. |
| * | |
| * | To next stage: |
| * | Until all supporting trees are updated. |
| * V |
| * Transaction N [[TRANS_STATE_UNBLOCKED]] |
| * | Transaction N+1 |
| * | All needed trees are modified, thus we only [[TRANS_STATE_RUNNING]] |
| * | need to write them back to disk and update | |
| * | super blocks. | |
| * | | |
| * | At this stage, new transaction is allowed to | |
| * | start. | |
| * | All new start_transaction() calls will be | |
| * | attached to transid N+1. | |
| * | | |
| * | To next stage: | |
| * | Until all tree blocks are super blocks are | |
| * | written to block devices | |
| * V | |
| * Transaction N [[TRANS_STATE_COMPLETED]] V |
| * All tree blocks and super blocks are written. Transaction N+1 |
| * This transaction is finished and all its [[TRANS_STATE_COMMIT_START]] |
| * data structures will be cleaned up. | Life goes on |
| */ |
| static const unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = { |
| [TRANS_STATE_RUNNING] = 0U, |
| [TRANS_STATE_COMMIT_START] = (__TRANS_START | __TRANS_ATTACH), |
| [TRANS_STATE_COMMIT_DOING] = (__TRANS_START | |
| __TRANS_ATTACH | |
| __TRANS_JOIN | |
| __TRANS_JOIN_NOSTART), |
| [TRANS_STATE_UNBLOCKED] = (__TRANS_START | |
| __TRANS_ATTACH | |
| __TRANS_JOIN | |
| __TRANS_JOIN_NOLOCK | |
| __TRANS_JOIN_NOSTART), |
| [TRANS_STATE_SUPER_COMMITTED] = (__TRANS_START | |
| __TRANS_ATTACH | |
| __TRANS_JOIN | |
| __TRANS_JOIN_NOLOCK | |
| __TRANS_JOIN_NOSTART), |
| [TRANS_STATE_COMPLETED] = (__TRANS_START | |
| __TRANS_ATTACH | |
| __TRANS_JOIN | |
| __TRANS_JOIN_NOLOCK | |
| __TRANS_JOIN_NOSTART), |
| }; |
| |
| void btrfs_put_transaction(struct btrfs_transaction *transaction) |
| { |
| WARN_ON(refcount_read(&transaction->use_count) == 0); |
| if (refcount_dec_and_test(&transaction->use_count)) { |
| BUG_ON(!list_empty(&transaction->list)); |
| WARN_ON(!RB_EMPTY_ROOT( |
| &transaction->delayed_refs.href_root.rb_root)); |
| WARN_ON(!RB_EMPTY_ROOT( |
| &transaction->delayed_refs.dirty_extent_root)); |
| if (transaction->delayed_refs.pending_csums) |
| btrfs_err(transaction->fs_info, |
| "pending csums is %llu", |
| transaction->delayed_refs.pending_csums); |
| /* |
| * If any block groups are found in ->deleted_bgs then it's |
| * because the transaction was aborted and a commit did not |
| * happen (things failed before writing the new superblock |
| * and calling btrfs_finish_extent_commit()), so we can not |
| * discard the physical locations of the block groups. |
| */ |
| while (!list_empty(&transaction->deleted_bgs)) { |
| struct btrfs_block_group *cache; |
| |
| cache = list_first_entry(&transaction->deleted_bgs, |
| struct btrfs_block_group, |
| bg_list); |
| list_del_init(&cache->bg_list); |
| btrfs_unfreeze_block_group(cache); |
| btrfs_put_block_group(cache); |
| } |
| WARN_ON(!list_empty(&transaction->dev_update_list)); |
| kfree(transaction); |
| } |
| } |
| |
| static noinline void switch_commit_roots(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_transaction *cur_trans = trans->transaction; |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_root *root, *tmp; |
| struct btrfs_caching_control *caching_ctl, *next; |
| |
| /* |
| * At this point no one can be using this transaction to modify any tree |
| * and no one can start another transaction to modify any tree either. |
| */ |
| ASSERT(cur_trans->state == TRANS_STATE_COMMIT_DOING); |
| |
| down_write(&fs_info->commit_root_sem); |
| |
| if (test_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags)) |
| fs_info->last_reloc_trans = trans->transid; |
| |
| list_for_each_entry_safe(root, tmp, &cur_trans->switch_commits, |
| dirty_list) { |
| list_del_init(&root->dirty_list); |
| free_extent_buffer(root->commit_root); |
| root->commit_root = btrfs_root_node(root); |
| extent_io_tree_release(&root->dirty_log_pages); |
| btrfs_qgroup_clean_swapped_blocks(root); |
| } |
| |
| /* We can free old roots now. */ |
| spin_lock(&cur_trans->dropped_roots_lock); |
| while (!list_empty(&cur_trans->dropped_roots)) { |
| root = list_first_entry(&cur_trans->dropped_roots, |
| struct btrfs_root, root_list); |
| list_del_init(&root->root_list); |
| spin_unlock(&cur_trans->dropped_roots_lock); |
| btrfs_free_log(trans, root); |
| btrfs_drop_and_free_fs_root(fs_info, root); |
| spin_lock(&cur_trans->dropped_roots_lock); |
| } |
| spin_unlock(&cur_trans->dropped_roots_lock); |
| |
| /* |
| * We have to update the last_byte_to_unpin under the commit_root_sem, |
| * at the same time we swap out the commit roots. |
| * |
| * This is because we must have a real view of the last spot the caching |
| * kthreads were while caching. Consider the following views of the |
| * extent tree for a block group |
| * |
| * commit root |
| * +----+----+----+----+----+----+----+ |
| * |\\\\| |\\\\|\\\\| |\\\\|\\\\| |
| * +----+----+----+----+----+----+----+ |
| * 0 1 2 3 4 5 6 7 |
| * |
| * new commit root |
| * +----+----+----+----+----+----+----+ |
| * | | | |\\\\| | |\\\\| |
| * +----+----+----+----+----+----+----+ |
| * 0 1 2 3 4 5 6 7 |
| * |
| * If the cache_ctl->progress was at 3, then we are only allowed to |
| * unpin [0,1) and [2,3], because the caching thread has already |
| * processed those extents. We are not allowed to unpin [5,6), because |
| * the caching thread will re-start it's search from 3, and thus find |
| * the hole from [4,6) to add to the free space cache. |
| */ |
| write_lock(&fs_info->block_group_cache_lock); |
| list_for_each_entry_safe(caching_ctl, next, |
| &fs_info->caching_block_groups, list) { |
| struct btrfs_block_group *cache = caching_ctl->block_group; |
| |
| if (btrfs_block_group_done(cache)) { |
| cache->last_byte_to_unpin = (u64)-1; |
| list_del_init(&caching_ctl->list); |
| btrfs_put_caching_control(caching_ctl); |
| } else { |
| cache->last_byte_to_unpin = caching_ctl->progress; |
| } |
| } |
| write_unlock(&fs_info->block_group_cache_lock); |
| up_write(&fs_info->commit_root_sem); |
| } |
| |
| static inline void extwriter_counter_inc(struct btrfs_transaction *trans, |
| unsigned int type) |
| { |
| if (type & TRANS_EXTWRITERS) |
| atomic_inc(&trans->num_extwriters); |
| } |
| |
| static inline void extwriter_counter_dec(struct btrfs_transaction *trans, |
| unsigned int type) |
| { |
| if (type & TRANS_EXTWRITERS) |
| atomic_dec(&trans->num_extwriters); |
| } |
| |
| static inline void extwriter_counter_init(struct btrfs_transaction *trans, |
| unsigned int type) |
| { |
| atomic_set(&trans->num_extwriters, ((type & TRANS_EXTWRITERS) ? 1 : 0)); |
| } |
| |
| static inline int extwriter_counter_read(struct btrfs_transaction *trans) |
| { |
| return atomic_read(&trans->num_extwriters); |
| } |
| |
| /* |
| * To be called after doing the chunk btree updates right after allocating a new |
| * chunk (after btrfs_chunk_alloc_add_chunk_item() is called), when removing a |
| * chunk after all chunk btree updates and after finishing the second phase of |
| * chunk allocation (btrfs_create_pending_block_groups()) in case some block |
| * group had its chunk item insertion delayed to the second phase. |
| */ |
| void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| |
| if (!trans->chunk_bytes_reserved) |
| return; |
| |
| btrfs_block_rsv_release(fs_info, &fs_info->chunk_block_rsv, |
| trans->chunk_bytes_reserved, NULL); |
| trans->chunk_bytes_reserved = 0; |
| } |
| |
| /* |
| * either allocate a new transaction or hop into the existing one |
| */ |
| static noinline int join_transaction(struct btrfs_fs_info *fs_info, |
| unsigned int type) |
| { |
| struct btrfs_transaction *cur_trans; |
| |
| spin_lock(&fs_info->trans_lock); |
| loop: |
| /* The file system has been taken offline. No new transactions. */ |
| if (BTRFS_FS_ERROR(fs_info)) { |
| spin_unlock(&fs_info->trans_lock); |
| return -EROFS; |
| } |
| |
| cur_trans = fs_info->running_transaction; |
| if (cur_trans) { |
| if (TRANS_ABORTED(cur_trans)) { |
| spin_unlock(&fs_info->trans_lock); |
| return cur_trans->aborted; |
| } |
| if (btrfs_blocked_trans_types[cur_trans->state] & type) { |
| spin_unlock(&fs_info->trans_lock); |
| return -EBUSY; |
| } |
| refcount_inc(&cur_trans->use_count); |
| atomic_inc(&cur_trans->num_writers); |
| extwriter_counter_inc(cur_trans, type); |
| spin_unlock(&fs_info->trans_lock); |
| return 0; |
| } |
| spin_unlock(&fs_info->trans_lock); |
| |
| /* |
| * If we are ATTACH, we just want to catch the current transaction, |
| * and commit it. If there is no transaction, just return ENOENT. |
| */ |
| if (type == TRANS_ATTACH) |
| return -ENOENT; |
| |
| /* |
| * JOIN_NOLOCK only happens during the transaction commit, so |
| * it is impossible that ->running_transaction is NULL |
| */ |
| BUG_ON(type == TRANS_JOIN_NOLOCK); |
| |
| cur_trans = kmalloc(sizeof(*cur_trans), GFP_NOFS); |
| if (!cur_trans) |
| return -ENOMEM; |
| |
| spin_lock(&fs_info->trans_lock); |
| if (fs_info->running_transaction) { |
| /* |
| * someone started a transaction after we unlocked. Make sure |
| * to redo the checks above |
| */ |
| kfree(cur_trans); |
| goto loop; |
| } else if (BTRFS_FS_ERROR(fs_info)) { |
| spin_unlock(&fs_info->trans_lock); |
| kfree(cur_trans); |
| return -EROFS; |
| } |
| |
| cur_trans->fs_info = fs_info; |
| atomic_set(&cur_trans->pending_ordered, 0); |
| init_waitqueue_head(&cur_trans->pending_wait); |
| atomic_set(&cur_trans->num_writers, 1); |
| extwriter_counter_init(cur_trans, type); |
| init_waitqueue_head(&cur_trans->writer_wait); |
| init_waitqueue_head(&cur_trans->commit_wait); |
| cur_trans->state = TRANS_STATE_RUNNING; |
| /* |
| * One for this trans handle, one so it will live on until we |
| * commit the transaction. |
| */ |
| refcount_set(&cur_trans->use_count, 2); |
| cur_trans->flags = 0; |
| cur_trans->start_time = ktime_get_seconds(); |
| |
| memset(&cur_trans->delayed_refs, 0, sizeof(cur_trans->delayed_refs)); |
| |
| cur_trans->delayed_refs.href_root = RB_ROOT_CACHED; |
| cur_trans->delayed_refs.dirty_extent_root = RB_ROOT; |
| atomic_set(&cur_trans->delayed_refs.num_entries, 0); |
| |
| /* |
| * although the tree mod log is per file system and not per transaction, |
| * the log must never go across transaction boundaries. |
| */ |
| smp_mb(); |
| if (!list_empty(&fs_info->tree_mod_seq_list)) |
| WARN(1, KERN_ERR "BTRFS: tree_mod_seq_list not empty when creating a fresh transaction\n"); |
| if (!RB_EMPTY_ROOT(&fs_info->tree_mod_log)) |
| WARN(1, KERN_ERR "BTRFS: tree_mod_log rb tree not empty when creating a fresh transaction\n"); |
| atomic64_set(&fs_info->tree_mod_seq, 0); |
| |
| spin_lock_init(&cur_trans->delayed_refs.lock); |
| |
| INIT_LIST_HEAD(&cur_trans->pending_snapshots); |
| INIT_LIST_HEAD(&cur_trans->dev_update_list); |
| INIT_LIST_HEAD(&cur_trans->switch_commits); |
| INIT_LIST_HEAD(&cur_trans->dirty_bgs); |
| INIT_LIST_HEAD(&cur_trans->io_bgs); |
| INIT_LIST_HEAD(&cur_trans->dropped_roots); |
| mutex_init(&cur_trans->cache_write_mutex); |
| spin_lock_init(&cur_trans->dirty_bgs_lock); |
| INIT_LIST_HEAD(&cur_trans->deleted_bgs); |
| spin_lock_init(&cur_trans->dropped_roots_lock); |
| INIT_LIST_HEAD(&cur_trans->releasing_ebs); |
| spin_lock_init(&cur_trans->releasing_ebs_lock); |
| list_add_tail(&cur_trans->list, &fs_info->trans_list); |
| extent_io_tree_init(fs_info, &cur_trans->dirty_pages, |
| IO_TREE_TRANS_DIRTY_PAGES, fs_info->btree_inode); |
| extent_io_tree_init(fs_info, &cur_trans->pinned_extents, |
| IO_TREE_FS_PINNED_EXTENTS, NULL); |
| fs_info->generation++; |
| cur_trans->transid = fs_info->generation; |
| fs_info->running_transaction = cur_trans; |
| cur_trans->aborted = 0; |
| spin_unlock(&fs_info->trans_lock); |
| |
| return 0; |
| } |
| |
| /* |
| * This does all the record keeping required to make sure that a shareable root |
| * is properly recorded in a given transaction. This is required to make sure |
| * the old root from before we joined the transaction is deleted when the |
| * transaction commits. |
| */ |
| static int record_root_in_trans(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| int force) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| int ret = 0; |
| |
| if ((test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && |
| root->last_trans < trans->transid) || force) { |
| WARN_ON(!force && root->commit_root != root->node); |
| |
| /* |
| * see below for IN_TRANS_SETUP usage rules |
| * we have the reloc mutex held now, so there |
| * is only one writer in this function |
| */ |
| set_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state); |
| |
| /* make sure readers find IN_TRANS_SETUP before |
| * they find our root->last_trans update |
| */ |
| smp_wmb(); |
| |
| spin_lock(&fs_info->fs_roots_lock); |
| if (root->last_trans == trans->transid && !force) { |
| spin_unlock(&fs_info->fs_roots_lock); |
| return 0; |
| } |
| xa_set_mark(&fs_info->fs_roots, |
| (unsigned long)root->root_key.objectid, |
| BTRFS_ROOT_TRANS_TAG); |
| spin_unlock(&fs_info->fs_roots_lock); |
| root->last_trans = trans->transid; |
| |
| /* this is pretty tricky. We don't want to |
| * take the relocation lock in btrfs_record_root_in_trans |
| * unless we're really doing the first setup for this root in |
| * this transaction. |
| * |
| * Normally we'd use root->last_trans as a flag to decide |
| * if we want to take the expensive mutex. |
| * |
| * But, we have to set root->last_trans before we |
| * init the relocation root, otherwise, we trip over warnings |
| * in ctree.c. The solution used here is to flag ourselves |
| * with root IN_TRANS_SETUP. When this is 1, we're still |
| * fixing up the reloc trees and everyone must wait. |
| * |
| * When this is zero, they can trust root->last_trans and fly |
| * through btrfs_record_root_in_trans without having to take the |
| * lock. smp_wmb() makes sure that all the writes above are |
| * done before we pop in the zero below |
| */ |
| ret = btrfs_init_reloc_root(trans, root); |
| smp_mb__before_atomic(); |
| clear_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state); |
| } |
| return ret; |
| } |
| |
| |
| void btrfs_add_dropped_root(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct btrfs_transaction *cur_trans = trans->transaction; |
| |
| /* Add ourselves to the transaction dropped list */ |
| spin_lock(&cur_trans->dropped_roots_lock); |
| list_add_tail(&root->root_list, &cur_trans->dropped_roots); |
| spin_unlock(&cur_trans->dropped_roots_lock); |
| |
| /* Make sure we don't try to update the root at commit time */ |
| xa_clear_mark(&fs_info->fs_roots, |
| (unsigned long)root->root_key.objectid, |
| BTRFS_ROOT_TRANS_TAG); |
| } |
| |
| int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| int ret; |
| |
| if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) |
| return 0; |
| |
| /* |
| * see record_root_in_trans for comments about IN_TRANS_SETUP usage |
| * and barriers |
| */ |
| smp_rmb(); |
| if (root->last_trans == trans->transid && |
| !test_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state)) |
| return 0; |
| |
| mutex_lock(&fs_info->reloc_mutex); |
| ret = record_root_in_trans(trans, root, 0); |
| mutex_unlock(&fs_info->reloc_mutex); |
| |
| return ret; |
| } |
| |
| static inline int is_transaction_blocked(struct btrfs_transaction *trans) |
| { |
| return (trans->state >= TRANS_STATE_COMMIT_START && |
| trans->state < TRANS_STATE_UNBLOCKED && |
| !TRANS_ABORTED(trans)); |
| } |
| |
| /* wait for commit against the current transaction to become unblocked |
| * when this is done, it is safe to start a new transaction, but the current |
| * transaction might not be fully on disk. |
| */ |
| static void wait_current_trans(struct btrfs_fs_info *fs_info) |
| { |
| struct btrfs_transaction *cur_trans; |
| |
| spin_lock(&fs_info->trans_lock); |
| cur_trans = fs_info->running_transaction; |
| if (cur_trans && is_transaction_blocked(cur_trans)) { |
| refcount_inc(&cur_trans->use_count); |
| spin_unlock(&fs_info->trans_lock); |
| |
| wait_event(fs_info->transaction_wait, |
| cur_trans->state >= TRANS_STATE_UNBLOCKED || |
| TRANS_ABORTED(cur_trans)); |
| btrfs_put_transaction(cur_trans); |
| } else { |
| spin_unlock(&fs_info->trans_lock); |
| } |
| } |
| |
| static int may_wait_transaction(struct btrfs_fs_info *fs_info, int type) |
| { |
| if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) |
| return 0; |
| |
| if (type == TRANS_START) |
| return 1; |
| |
| return 0; |
| } |
| |
| static inline bool need_reserve_reloc_root(struct btrfs_root *root) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| |
| if (!fs_info->reloc_ctl || |
| !test_bit(BTRFS_ROOT_SHAREABLE, &root->state) || |
| root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
| root->reloc_root) |
| return false; |
| |
| return true; |
| } |
| |
| static struct btrfs_trans_handle * |
| start_transaction(struct btrfs_root *root, unsigned int num_items, |
| unsigned int type, enum btrfs_reserve_flush_enum flush, |
| bool enforce_qgroups) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv; |
| struct btrfs_trans_handle *h; |
| struct btrfs_transaction *cur_trans; |
| u64 num_bytes = 0; |
| u64 qgroup_reserved = 0; |
| bool reloc_reserved = false; |
| bool do_chunk_alloc = false; |
| int ret; |
| |
| if (BTRFS_FS_ERROR(fs_info)) |
| return ERR_PTR(-EROFS); |
| |
| if (current->journal_info) { |
| WARN_ON(type & TRANS_EXTWRITERS); |
| h = current->journal_info; |
| refcount_inc(&h->use_count); |
| WARN_ON(refcount_read(&h->use_count) > 2); |
| h->orig_rsv = h->block_rsv; |
| h->block_rsv = NULL; |
| goto got_it; |
| } |
| |
| /* |
| * Do the reservation before we join the transaction so we can do all |
| * the appropriate flushing if need be. |
| */ |
| if (num_items && root != fs_info->chunk_root) { |
| struct btrfs_block_rsv *rsv = &fs_info->trans_block_rsv; |
| u64 delayed_refs_bytes = 0; |
| |
| qgroup_reserved = num_items * fs_info->nodesize; |
| ret = btrfs_qgroup_reserve_meta_pertrans(root, qgroup_reserved, |
| enforce_qgroups); |
| if (ret) |
| return ERR_PTR(ret); |
| |
| /* |
| * We want to reserve all the bytes we may need all at once, so |
| * we only do 1 enospc flushing cycle per transaction start. We |
| * accomplish this by simply assuming we'll do 2 x num_items |
| * worth of delayed refs updates in this trans handle, and |
| * refill that amount for whatever is missing in the reserve. |
| */ |
| num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_items); |
| if (flush == BTRFS_RESERVE_FLUSH_ALL && |
| delayed_refs_rsv->full == 0) { |
| delayed_refs_bytes = num_bytes; |
| num_bytes <<= 1; |
| } |
| |
| /* |
| * Do the reservation for the relocation root creation |
| */ |
| if (need_reserve_reloc_root(root)) { |
| num_bytes += fs_info->nodesize; |
| reloc_reserved = true; |
| } |
| |
| ret = btrfs_block_rsv_add(fs_info, rsv, num_bytes, flush); |
| if (ret) |
| goto reserve_fail; |
| if (delayed_refs_bytes) { |
| btrfs_migrate_to_delayed_refs_rsv(fs_info, rsv, |
| delayed_refs_bytes); |
| num_bytes -= delayed_refs_bytes; |
| } |
| |
| if (rsv->space_info->force_alloc) |
| do_chunk_alloc = true; |
| } else if (num_items == 0 && flush == BTRFS_RESERVE_FLUSH_ALL && |
| !delayed_refs_rsv->full) { |
| /* |
| * Some people call with btrfs_start_transaction(root, 0) |
| * because they can be throttled, but have some other mechanism |
| * for reserving space. We still want these guys to refill the |
| * delayed block_rsv so just add 1 items worth of reservation |
| * here. |
| */ |
| ret = btrfs_delayed_refs_rsv_refill(fs_info, flush); |
| if (ret) |
| goto reserve_fail; |
| } |
| again: |
| h = kmem_cache_zalloc(btrfs_trans_handle_cachep, GFP_NOFS); |
| if (!h) { |
| ret = -ENOMEM; |
| goto alloc_fail; |
| } |
| |
| /* |
| * If we are JOIN_NOLOCK we're already committing a transaction and |
| * waiting on this guy, so we don't need to do the sb_start_intwrite |
| * because we're already holding a ref. We need this because we could |
| * have raced in and did an fsync() on a file which can kick a commit |
| * and then we deadlock with somebody doing a freeze. |
| * |
| * If we are ATTACH, it means we just want to catch the current |
| * transaction and commit it, so we needn't do sb_start_intwrite(). |
| */ |
| if (type & __TRANS_FREEZABLE) |
| sb_start_intwrite(fs_info->sb); |
| |
| if (may_wait_transaction(fs_info, type)) |
| wait_current_trans(fs_info); |
| |
| do { |
| ret = join_transaction(fs_info, type); |
| if (ret == -EBUSY) { |
| wait_current_trans(fs_info); |
| if (unlikely(type == TRANS_ATTACH || |
| type == TRANS_JOIN_NOSTART)) |
| ret = -ENOENT; |
| } |
| } while (ret == -EBUSY); |
| |
| if (ret < 0) |
| goto join_fail; |
| |
| cur_trans = fs_info->running_transaction; |
| |
| h->transid = cur_trans->transid; |
| h->transaction = cur_trans; |
| refcount_set(&h->use_count, 1); |
| h->fs_info = root->fs_info; |
| |
| h->type = type; |
| INIT_LIST_HEAD(&h->new_bgs); |
| |
| smp_mb(); |
| if (cur_trans->state >= TRANS_STATE_COMMIT_START && |
| may_wait_transaction(fs_info, type)) { |
| current->journal_info = h; |
| btrfs_commit_transaction(h); |
| goto again; |
| } |
| |
| if (num_bytes) { |
| trace_btrfs_space_reservation(fs_info, "transaction", |
| h->transid, num_bytes, 1); |
| h->block_rsv = &fs_info->trans_block_rsv; |
| h->bytes_reserved = num_bytes; |
| h->reloc_reserved = reloc_reserved; |
| } |
| |
| got_it: |
| if (!current->journal_info) |
| current->journal_info = h; |
| |
| /* |
| * If the space_info is marked ALLOC_FORCE then we'll get upgraded to |
| * ALLOC_FORCE the first run through, and then we won't allocate for |
| * anybody else who races in later. We don't care about the return |
| * value here. |
| */ |
| if (do_chunk_alloc && num_bytes) { |
| u64 flags = h->block_rsv->space_info->flags; |
| |
| btrfs_chunk_alloc(h, btrfs_get_alloc_profile(fs_info, flags), |
| CHUNK_ALLOC_NO_FORCE); |
| } |
| |
| /* |
| * btrfs_record_root_in_trans() needs to alloc new extents, and may |
| * call btrfs_join_transaction() while we're also starting a |
| * transaction. |
| * |
| * Thus it need to be called after current->journal_info initialized, |
| * or we can deadlock. |
| */ |
| ret = btrfs_record_root_in_trans(h, root); |
| if (ret) { |
| /* |
| * The transaction handle is fully initialized and linked with |
| * other structures so it needs to be ended in case of errors, |
| * not just freed. |
| */ |
| btrfs_end_transaction(h); |
| return ERR_PTR(ret); |
| } |
| |
| return h; |
| |
| join_fail: |
| if (type & __TRANS_FREEZABLE) |
| sb_end_intwrite(fs_info->sb); |
| kmem_cache_free(btrfs_trans_handle_cachep, h); |
| alloc_fail: |
| if (num_bytes) |
| btrfs_block_rsv_release(fs_info, &fs_info->trans_block_rsv, |
| num_bytes, NULL); |
| reserve_fail: |
| btrfs_qgroup_free_meta_pertrans(root, qgroup_reserved); |
| return ERR_PTR(ret); |
| } |
| |
| struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, |
| unsigned int num_items) |
| { |
| return start_transaction(root, num_items, TRANS_START, |
| BTRFS_RESERVE_FLUSH_ALL, true); |
| } |
| |
| struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv( |
| struct btrfs_root *root, |
| unsigned int num_items) |
| { |
| return start_transaction(root, num_items, TRANS_START, |
| BTRFS_RESERVE_FLUSH_ALL_STEAL, false); |
| } |
| |
| struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root) |
| { |
| return start_transaction(root, 0, TRANS_JOIN, BTRFS_RESERVE_NO_FLUSH, |
| true); |
| } |
| |
| struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root) |
| { |
| return start_transaction(root, 0, TRANS_JOIN_NOLOCK, |
| BTRFS_RESERVE_NO_FLUSH, true); |
| } |
| |
| /* |
| * Similar to regular join but it never starts a transaction when none is |
| * running or after waiting for the current one to finish. |
| */ |
| struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root) |
| { |
| return start_transaction(root, 0, TRANS_JOIN_NOSTART, |
| BTRFS_RESERVE_NO_FLUSH, true); |
| } |
| |
| /* |
| * btrfs_attach_transaction() - catch the running transaction |
| * |
| * It is used when we want to commit the current the transaction, but |
| * don't want to start a new one. |
| * |
| * Note: If this function return -ENOENT, it just means there is no |
| * running transaction. But it is possible that the inactive transaction |
| * is still in the memory, not fully on disk. If you hope there is no |
| * inactive transaction in the fs when -ENOENT is returned, you should |
| * invoke |
| * btrfs_attach_transaction_barrier() |
| */ |
| struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root) |
| { |
| return start_transaction(root, 0, TRANS_ATTACH, |
| BTRFS_RESERVE_NO_FLUSH, true); |
| } |
| |
| /* |
| * btrfs_attach_transaction_barrier() - catch the running transaction |
| * |
| * It is similar to the above function, the difference is this one |
| * will wait for all the inactive transactions until they fully |
| * complete. |
| */ |
| struct btrfs_trans_handle * |
| btrfs_attach_transaction_barrier(struct btrfs_root *root) |
| { |
| struct btrfs_trans_handle *trans; |
| |
| trans = start_transaction(root, 0, TRANS_ATTACH, |
| BTRFS_RESERVE_NO_FLUSH, true); |
| if (trans == ERR_PTR(-ENOENT)) |
| btrfs_wait_for_commit(root->fs_info, 0); |
| |
| return trans; |
| } |
| |
| /* Wait for a transaction commit to reach at least the given state. */ |
| static noinline void wait_for_commit(struct btrfs_transaction *commit, |
| const enum btrfs_trans_state min_state) |
| { |
| struct btrfs_fs_info *fs_info = commit->fs_info; |
| u64 transid = commit->transid; |
| bool put = false; |
| |
| while (1) { |
| wait_event(commit->commit_wait, commit->state >= min_state); |
| if (put) |
| btrfs_put_transaction(commit); |
| |
| if (min_state < TRANS_STATE_COMPLETED) |
| break; |
| |
| /* |
| * A transaction isn't really completed until all of the |
| * previous transactions are completed, but with fsync we can |
| * end up with SUPER_COMMITTED transactions before a COMPLETED |
| * transaction. Wait for those. |
| */ |
| |
| spin_lock(&fs_info->trans_lock); |
| commit = list_first_entry_or_null(&fs_info->trans_list, |
| struct btrfs_transaction, |
| list); |
| if (!commit || commit->transid > transid) { |
| spin_unlock(&fs_info->trans_lock); |
| break; |
| } |
| refcount_inc(&commit->use_count); |
| put = true; |
| spin_unlock(&fs_info->trans_lock); |
| } |
| } |
| |
| int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid) |
| { |
| struct btrfs_transaction *cur_trans = NULL, *t; |
| int ret = 0; |
| |
| if (transid) { |
| if (transid <= fs_info->last_trans_committed) |
| goto out; |
| |
| /* find specified transaction */ |
| spin_lock(&fs_info->trans_lock); |
| list_for_each_entry(t, &fs_info->trans_list, list) { |
| if (t->transid == transid) { |
| cur_trans = t; |
| refcount_inc(&cur_trans->use_count); |
| ret = 0; |
| break; |
| } |
| if (t->transid > transid) { |
| ret = 0; |
| break; |
| } |
| } |
| spin_unlock(&fs_info->trans_lock); |
| |
| /* |
| * The specified transaction doesn't exist, or we |
| * raced with btrfs_commit_transaction |
| */ |
| if (!cur_trans) { |
| if (transid > fs_info->last_trans_committed) |
| ret = -EINVAL; |
| goto out; |
| } |
| } else { |
| /* find newest transaction that is committing | committed */ |
| spin_lock(&fs_info->trans_lock); |
| list_for_each_entry_reverse(t, &fs_info->trans_list, |
| list) { |
| if (t->state >= TRANS_STATE_COMMIT_START) { |
| if (t->state == TRANS_STATE_COMPLETED) |
| break; |
| cur_trans = t; |
| refcount_inc(&cur_trans->use_count); |
| break; |
| } |
| } |
| spin_unlock(&fs_info->trans_lock); |
| if (!cur_trans) |
| goto out; /* nothing committing|committed */ |
| } |
| |
| wait_for_commit(cur_trans, TRANS_STATE_COMPLETED); |
| btrfs_put_transaction(cur_trans); |
| out: |
| return ret; |
| } |
| |
| void btrfs_throttle(struct btrfs_fs_info *fs_info) |
| { |
| wait_current_trans(fs_info); |
| } |
| |
| static bool should_end_transaction(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| |
| if (btrfs_check_space_for_delayed_refs(fs_info)) |
| return true; |
| |
| return !!btrfs_block_rsv_check(&fs_info->global_block_rsv, 5); |
| } |
| |
| bool btrfs_should_end_transaction(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_transaction *cur_trans = trans->transaction; |
| |
| if (cur_trans->state >= TRANS_STATE_COMMIT_START || |
| test_bit(BTRFS_DELAYED_REFS_FLUSHING, &cur_trans->delayed_refs.flags)) |
| return true; |
| |
| return should_end_transaction(trans); |
| } |
| |
| static void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans) |
| |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| |
| if (!trans->block_rsv) { |
| ASSERT(!trans->bytes_reserved); |
| return; |
| } |
| |
| if (!trans->bytes_reserved) |
| return; |
| |
| ASSERT(trans->block_rsv == &fs_info->trans_block_rsv); |
| trace_btrfs_space_reservation(fs_info, "transaction", |
| trans->transid, trans->bytes_reserved, 0); |
| btrfs_block_rsv_release(fs_info, trans->block_rsv, |
| trans->bytes_reserved, NULL); |
| trans->bytes_reserved = 0; |
| } |
| |
| static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, |
| int throttle) |
| { |
| struct btrfs_fs_info *info = trans->fs_info; |
| struct btrfs_transaction *cur_trans = trans->transaction; |
| int err = 0; |
| |
| if (refcount_read(&trans->use_count) > 1) { |
| refcount_dec(&trans->use_count); |
| trans->block_rsv = trans->orig_rsv; |
| return 0; |
| } |
| |
| btrfs_trans_release_metadata(trans); |
| trans->block_rsv = NULL; |
| |
| btrfs_create_pending_block_groups(trans); |
| |
| btrfs_trans_release_chunk_metadata(trans); |
| |
| if (trans->type & __TRANS_FREEZABLE) |
| sb_end_intwrite(info->sb); |
| |
| WARN_ON(cur_trans != info->running_transaction); |
| WARN_ON(atomic_read(&cur_trans->num_writers) < 1); |
| atomic_dec(&cur_trans->num_writers); |
| extwriter_counter_dec(cur_trans, trans->type); |
| |
| cond_wake_up(&cur_trans->writer_wait); |
| btrfs_put_transaction(cur_trans); |
| |
| if (current->journal_info == trans) |
| current->journal_info = NULL; |
| |
| if (throttle) |
| btrfs_run_delayed_iputs(info); |
| |
| if (TRANS_ABORTED(trans) || BTRFS_FS_ERROR(info)) { |
| wake_up_process(info->transaction_kthread); |
| if (TRANS_ABORTED(trans)) |
| err = trans->aborted; |
| else |
| err = -EROFS; |
| } |
| |
| kmem_cache_free(btrfs_trans_handle_cachep, trans); |
| return err; |
| } |
| |
| int btrfs_end_transaction(struct btrfs_trans_handle *trans) |
| { |
| return __btrfs_end_transaction(trans, 0); |
| } |
| |
| int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans) |
| { |
| return __btrfs_end_transaction(trans, 1); |
| } |
| |
| /* |
| * when btree blocks are allocated, they have some corresponding bits set for |
| * them in one of two extent_io trees. This is used to make sure all of |
| * those extents are sent to disk but does not wait on them |
| */ |
| int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info, |
| struct extent_io_tree *dirty_pages, int mark) |
| { |
| int err = 0; |
| int werr = 0; |
| struct address_space *mapping = fs_info->btree_inode->i_mapping; |
| struct extent_state *cached_state = NULL; |
| u64 start = 0; |
| u64 end; |
| |
| atomic_inc(&BTRFS_I(fs_info->btree_inode)->sync_writers); |
| while (!find_first_extent_bit(dirty_pages, start, &start, &end, |
| mark, &cached_state)) { |
| bool wait_writeback = false; |
| |
| err = convert_extent_bit(dirty_pages, start, end, |
| EXTENT_NEED_WAIT, |
| mark, &cached_state); |
| /* |
| * convert_extent_bit can return -ENOMEM, which is most of the |
| * time a temporary error. So when it happens, ignore the error |
| * and wait for writeback of this range to finish - because we |
| * failed to set the bit EXTENT_NEED_WAIT for the range, a call |
| * to __btrfs_wait_marked_extents() would not know that |
| * writeback for this range started and therefore wouldn't |
| * wait for it to finish - we don't want to commit a |
| * superblock that points to btree nodes/leafs for which |
| * writeback hasn't finished yet (and without errors). |
| * We cleanup any entries left in the io tree when committing |
| * the transaction (through extent_io_tree_release()). |
| */ |
| if (err == -ENOMEM) { |
| err = 0; |
| wait_writeback = true; |
| } |
| if (!err) |
| err = filemap_fdatawrite_range(mapping, start, end); |
| if (err) |
| werr = err; |
| else if (wait_writeback) |
| werr = filemap_fdatawait_range(mapping, start, end); |
| free_extent_state(cached_state); |
| cached_state = NULL; |
| cond_resched(); |
| start = end + 1; |
| } |
| atomic_dec(&BTRFS_I(fs_info->btree_inode)->sync_writers); |
| return werr; |
| } |
| |
| /* |
| * when btree blocks are allocated, they have some corresponding bits set for |
| * them in one of two extent_io trees. This is used to make sure all of |
| * those extents are on disk for transaction or log commit. We wait |
| * on all the pages and clear them from the dirty pages state tree |
| */ |
| static int __btrfs_wait_marked_extents(struct btrfs_fs_info *fs_info, |
| struct extent_io_tree *dirty_pages) |
| { |
| int err = 0; |
| int werr = 0; |
| struct address_space *mapping = fs_info->btree_inode->i_mapping; |
| struct extent_state *cached_state = NULL; |
| u64 start = 0; |
| u64 end; |
| |
| while (!find_first_extent_bit(dirty_pages, start, &start, &end, |
| EXTENT_NEED_WAIT, &cached_state)) { |
| /* |
| * Ignore -ENOMEM errors returned by clear_extent_bit(). |
| * When committing the transaction, we'll remove any entries |
| * left in the io tree. For a log commit, we don't remove them |
| * after committing the log because the tree can be accessed |
| * concurrently - we do it only at transaction commit time when |
| * it's safe to do it (through extent_io_tree_release()). |
| */ |
| err = clear_extent_bit(dirty_pages, start, end, |
| EXTENT_NEED_WAIT, 0, 0, &cached_state); |
| if (err == -ENOMEM) |
| err = 0; |
| if (!err) |
| err = filemap_fdatawait_range(mapping, start, end); |
| if (err) |
| werr = err; |
| free_extent_state(cached_state); |
| cached_state = NULL; |
| cond_resched(); |
| start = end + 1; |
| } |
| if (err) |
| werr = err; |
| return werr; |
| } |
| |
| static int btrfs_wait_extents(struct btrfs_fs_info *fs_info, |
| struct extent_io_tree *dirty_pages) |
| { |
| bool errors = false; |
| int err; |
| |
| err = __btrfs_wait_marked_extents(fs_info, dirty_pages); |
| if (test_and_clear_bit(BTRFS_FS_BTREE_ERR, &fs_info->flags)) |
| errors = true; |
| |
| if (errors && !err) |
| err = -EIO; |
| return err; |
| } |
| |
| int btrfs_wait_tree_log_extents(struct btrfs_root *log_root, int mark) |
| { |
| struct btrfs_fs_info *fs_info = log_root->fs_info; |
| struct extent_io_tree *dirty_pages = &log_root->dirty_log_pages; |
| bool errors = false; |
| int err; |
| |
| ASSERT(log_root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID); |
| |
| err = __btrfs_wait_marked_extents(fs_info, dirty_pages); |
| if ((mark & EXTENT_DIRTY) && |
| test_and_clear_bit(BTRFS_FS_LOG1_ERR, &fs_info->flags)) |
| errors = true; |
| |
| if ((mark & EXTENT_NEW) && |
| test_and_clear_bit(BTRFS_FS_LOG2_ERR, &fs_info->flags)) |
| errors = true; |
| |
| if (errors && !err) |
| err = -EIO; |
| return err; |
| } |
| |
| /* |
| * When btree blocks are allocated the corresponding extents are marked dirty. |
| * This function ensures such extents are persisted on disk for transaction or |
| * log commit. |
| * |
| * @trans: transaction whose dirty pages we'd like to write |
| */ |
| static int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans) |
| { |
| int ret; |
| int ret2; |
| struct extent_io_tree *dirty_pages = &trans->transaction->dirty_pages; |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct blk_plug plug; |
| |
| blk_start_plug(&plug); |
| ret = btrfs_write_marked_extents(fs_info, dirty_pages, EXTENT_DIRTY); |
| blk_finish_plug(&plug); |
| ret2 = btrfs_wait_extents(fs_info, dirty_pages); |
| |
| extent_io_tree_release(&trans->transaction->dirty_pages); |
| |
| if (ret) |
| return ret; |
| else if (ret2) |
| return ret2; |
| else |
| return 0; |
| } |
| |
| /* |
| * this is used to update the root pointer in the tree of tree roots. |
| * |
| * But, in the case of the extent allocation tree, updating the root |
| * pointer may allocate blocks which may change the root of the extent |
| * allocation tree. |
| * |
| * So, this loops and repeats and makes sure the cowonly root didn't |
| * change while the root pointer was being updated in the metadata. |
| */ |
| static int update_cowonly_root(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| int ret; |
| u64 old_root_bytenr; |
| u64 old_root_used; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct btrfs_root *tree_root = fs_info->tree_root; |
| |
| old_root_used = btrfs_root_used(&root->root_item); |
| |
| while (1) { |
| old_root_bytenr = btrfs_root_bytenr(&root->root_item); |
| if (old_root_bytenr == root->node->start && |
| old_root_used == btrfs_root_used(&root->root_item)) |
| break; |
| |
| btrfs_set_root_node(&root->root_item, root->node); |
| ret = btrfs_update_root(trans, tree_root, |
| &root->root_key, |
| &root->root_item); |
| if (ret) |
| return ret; |
| |
| old_root_used = btrfs_root_used(&root->root_item); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * update all the cowonly tree roots on disk |
| * |
| * The error handling in this function may not be obvious. Any of the |
| * failures will cause the file system to go offline. We still need |
| * to clean up the delayed refs. |
| */ |
| static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct list_head *dirty_bgs = &trans->transaction->dirty_bgs; |
| struct list_head *io_bgs = &trans->transaction->io_bgs; |
| struct list_head *next; |
| struct extent_buffer *eb; |
| int ret; |
| |
| /* |
| * At this point no one can be using this transaction to modify any tree |
| * and no one can start another transaction to modify any tree either. |
| */ |
| ASSERT(trans->transaction->state == TRANS_STATE_COMMIT_DOING); |
| |
| eb = btrfs_lock_root_node(fs_info->tree_root); |
| ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, |
| 0, &eb, BTRFS_NESTING_COW); |
| btrfs_tree_unlock(eb); |
| free_extent_buffer(eb); |
| |
| if (ret) |
| return ret; |
| |
| ret = btrfs_run_dev_stats(trans); |
| if (ret) |
| return ret; |
| ret = btrfs_run_dev_replace(trans); |
| if (ret) |
| return ret; |
| ret = btrfs_run_qgroups(trans); |
| if (ret) |
| return ret; |
| |
| ret = btrfs_setup_space_cache(trans); |
| if (ret) |
| return ret; |
| |
| again: |
| while (!list_empty(&fs_info->dirty_cowonly_roots)) { |
| struct btrfs_root *root; |
| next = fs_info->dirty_cowonly_roots.next; |
| list_del_init(next); |
| root = list_entry(next, struct btrfs_root, dirty_list); |
| clear_bit(BTRFS_ROOT_DIRTY, &root->state); |
| |
| list_add_tail(&root->dirty_list, |
| &trans->transaction->switch_commits); |
| ret = update_cowonly_root(trans, root); |
| if (ret) |
| return ret; |
| } |
| |
| /* Now flush any delayed refs generated by updating all of the roots */ |
| ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); |
| if (ret) |
| return ret; |
| |
| while (!list_empty(dirty_bgs) || !list_empty(io_bgs)) { |
| ret = btrfs_write_dirty_block_groups(trans); |
| if (ret) |
| return ret; |
| |
| /* |
| * We're writing the dirty block groups, which could generate |
| * delayed refs, which could generate more dirty block groups, |
| * so we want to keep this flushing in this loop to make sure |
| * everything gets run. |
| */ |
| ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); |
| if (ret) |
| return ret; |
| } |
| |
| if (!list_empty(&fs_info->dirty_cowonly_roots)) |
| goto again; |
| |
| /* Update dev-replace pointer once everything is committed */ |
| fs_info->dev_replace.committed_cursor_left = |
| fs_info->dev_replace.cursor_left_last_write_of_item; |
| |
| return 0; |
| } |
| |
| /* |
| * If we had a pending drop we need to see if there are any others left in our |
| * dead roots list, and if not clear our bit and wake any waiters. |
| */ |
| void btrfs_maybe_wake_unfinished_drop(struct btrfs_fs_info *fs_info) |
| { |
| /* |
| * We put the drop in progress roots at the front of the list, so if the |
| * first entry doesn't have UNFINISHED_DROP set we can wake everybody |
| * up. |
| */ |
| spin_lock(&fs_info->trans_lock); |
| if (!list_empty(&fs_info->dead_roots)) { |
| struct btrfs_root *root = list_first_entry(&fs_info->dead_roots, |
| struct btrfs_root, |
| root_list); |
| if (test_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state)) { |
| spin_unlock(&fs_info->trans_lock); |
| return; |
| } |
| } |
| spin_unlock(&fs_info->trans_lock); |
| |
| btrfs_wake_unfinished_drop(fs_info); |
| } |
| |
| /* |
| * dead roots are old snapshots that need to be deleted. This allocates |
| * a dirty root struct and adds it into the list of dead roots that need to |
| * be deleted |
| */ |
| void btrfs_add_dead_root(struct btrfs_root *root) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| |
| spin_lock(&fs_info->trans_lock); |
| if (list_empty(&root->root_list)) { |
| btrfs_grab_root(root); |
| |
| /* We want to process the partially complete drops first. */ |
| if (test_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state)) |
| list_add(&root->root_list, &fs_info->dead_roots); |
| else |
| list_add_tail(&root->root_list, &fs_info->dead_roots); |
| } |
| spin_unlock(&fs_info->trans_lock); |
| } |
| |
| /* |
| * Update each subvolume root and its relocation root, if it exists, in the tree |
| * of tree roots. Also free log roots if they exist. |
| */ |
| static noinline int commit_fs_roots(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_root *root; |
| unsigned long index; |
| |
| /* |
| * At this point no one can be using this transaction to modify any tree |
| * and no one can start another transaction to modify any tree either. |
| */ |
| ASSERT(trans->transaction->state == TRANS_STATE_COMMIT_DOING); |
| |
| spin_lock(&fs_info->fs_roots_lock); |
| xa_for_each_marked(&fs_info->fs_roots, index, root, BTRFS_ROOT_TRANS_TAG) { |
| int ret; |
| |
| /* |
| * At this point we can neither have tasks logging inodes |
| * from a root nor trying to commit a log tree. |
| */ |
| ASSERT(atomic_read(&root->log_writers) == 0); |
| ASSERT(atomic_read(&root->log_commit[0]) == 0); |
| ASSERT(atomic_read(&root->log_commit[1]) == 0); |
| |
| xa_clear_mark(&fs_info->fs_roots, |
| (unsigned long)root->root_key.objectid, |
| BTRFS_ROOT_TRANS_TAG); |
| spin_unlock(&fs_info->fs_roots_lock); |
| |
| btrfs_free_log(trans, root); |
| ret = btrfs_update_reloc_root(trans, root); |
| if (ret) |
| return ret; |
| |
| /* See comments in should_cow_block() */ |
| clear_bit(BTRFS_ROOT_FORCE_COW, &root->state); |
| smp_mb__after_atomic(); |
| |
| if (root->commit_root != root->node) { |
| list_add_tail(&root->dirty_list, |
| &trans->transaction->switch_commits); |
| btrfs_set_root_node(&root->root_item, root->node); |
| } |
| |
| ret = btrfs_update_root(trans, fs_info->tree_root, |
| &root->root_key, &root->root_item); |
| if (ret) |
| return ret; |
| spin_lock(&fs_info->fs_roots_lock); |
| btrfs_qgroup_free_meta_all_pertrans(root); |
| } |
| spin_unlock(&fs_info->fs_roots_lock); |
| return 0; |
| } |
| |
| /* |
| * defrag a given btree. |
| * Every leaf in the btree is read and defragged. |
| */ |
| int btrfs_defrag_root(struct btrfs_root *root) |
| { |
| struct btrfs_fs_info *info = root->fs_info; |
| struct btrfs_trans_handle *trans; |
| int ret; |
| |
| if (test_and_set_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state)) |
| return 0; |
| |
| while (1) { |
| trans = btrfs_start_transaction(root, 0); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| break; |
| } |
| |
| ret = btrfs_defrag_leaves(trans, root); |
| |
| btrfs_end_transaction(trans); |
| btrfs_btree_balance_dirty(info); |
| cond_resched(); |
| |
| if (btrfs_fs_closing(info) || ret != -EAGAIN) |
| break; |
| |
| if (btrfs_defrag_cancelled(info)) { |
| btrfs_debug(info, "defrag_root cancelled"); |
| ret = -EAGAIN; |
| break; |
| } |
| } |
| clear_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state); |
| return ret; |
| } |
| |
| /* |
| * Do all special snapshot related qgroup dirty hack. |
| * |
| * Will do all needed qgroup inherit and dirty hack like switch commit |
| * roots inside one transaction and write all btree into disk, to make |
| * qgroup works. |
| */ |
| static int qgroup_account_snapshot(struct btrfs_trans_handle *trans, |
| struct btrfs_root *src, |
| struct btrfs_root *parent, |
| struct btrfs_qgroup_inherit *inherit, |
| u64 dst_objectid) |
| { |
| struct btrfs_fs_info *fs_info = src->fs_info; |
| int ret; |
| |
| /* |
| * Save some performance in the case that qgroups are not |
| * enabled. If this check races with the ioctl, rescan will |
| * kick in anyway. |
| */ |
| if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) |
| return 0; |
| |
| /* |
| * Ensure dirty @src will be committed. Or, after coming |
| * commit_fs_roots() and switch_commit_roots(), any dirty but not |
| * recorded root will never be updated again, causing an outdated root |
| * item. |
| */ |
| ret = record_root_in_trans(trans, src, 1); |
| if (ret) |
| return ret; |
| |
| /* |
| * btrfs_qgroup_inherit relies on a consistent view of the usage for the |
| * src root, so we must run the delayed refs here. |
| * |
| * However this isn't particularly fool proof, because there's no |
| * synchronization keeping us from changing the tree after this point |
| * before we do the qgroup_inherit, or even from making changes while |
| * we're doing the qgroup_inherit. But that's a problem for the future, |
| * for now flush the delayed refs to narrow the race window where the |
| * qgroup counters could end up wrong. |
| */ |
| ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| return ret; |
| } |
| |
| ret = commit_fs_roots(trans); |
| if (ret) |
| goto out; |
| ret = btrfs_qgroup_account_extents(trans); |
| if (ret < 0) |
| goto out; |
| |
| /* Now qgroup are all updated, we can inherit it to new qgroups */ |
| ret = btrfs_qgroup_inherit(trans, src->root_key.objectid, dst_objectid, |
| inherit); |
| if (ret < 0) |
| goto out; |
| |
| /* |
| * Now we do a simplified commit transaction, which will: |
| * 1) commit all subvolume and extent tree |
| * To ensure all subvolume and extent tree have a valid |
| * commit_root to accounting later insert_dir_item() |
| * 2) write all btree blocks onto disk |
| * This is to make sure later btree modification will be cowed |
| * Or commit_root can be populated and cause wrong qgroup numbers |
| * In this simplified commit, we don't really care about other trees |
| * like chunk and root tree, as they won't affect qgroup. |
| * And we don't write super to avoid half committed status. |
| */ |
| ret = commit_cowonly_roots(trans); |
| if (ret) |
| goto out; |
| switch_commit_roots(trans); |
| ret = btrfs_write_and_wait_transaction(trans); |
| if (ret) |
| btrfs_handle_fs_error(fs_info, ret, |
| "Error while writing out transaction for qgroup"); |
| |
| out: |
| /* |
| * Force parent root to be updated, as we recorded it before so its |
| * last_trans == cur_transid. |
| * Or it won't be committed again onto disk after later |
| * insert_dir_item() |
| */ |
| if (!ret) |
| ret = record_root_in_trans(trans, parent, 1); |
| return ret; |
| } |
| |
| /* |
| * new snapshots need to be created at a very specific time in the |
| * transaction commit. This does the actual creation. |
| * |
| * Note: |
| * If the error which may affect the commitment of the current transaction |
| * happens, we should return the error number. If the error which just affect |
| * the creation of the pending snapshots, just return 0. |
| */ |
| static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, |
| struct btrfs_pending_snapshot *pending) |
| { |
| |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_key key; |
| struct btrfs_root_item *new_root_item; |
| struct btrfs_root *tree_root = fs_info->tree_root; |
| struct btrfs_root *root = pending->root; |
| struct btrfs_root *parent_root; |
| struct btrfs_block_rsv *rsv; |
| struct inode *parent_inode; |
| struct btrfs_path *path; |
| struct btrfs_dir_item *dir_item; |
| struct dentry *dentry; |
| struct extent_buffer *tmp; |
| struct extent_buffer *old; |
| struct timespec64 cur_time; |
| int ret = 0; |
| u64 to_reserve = 0; |
| u64 index = 0; |
| u64 objectid; |
| u64 root_flags; |
| |
| ASSERT(pending->path); |
| path = pending->path; |
| |
| ASSERT(pending->root_item); |
| new_root_item = pending->root_item; |
| |
| pending->error = btrfs_get_free_objectid(tree_root, &objectid); |
| if (pending->error) |
| goto no_free_objectid; |
| |
| /* |
| * Make qgroup to skip current new snapshot's qgroupid, as it is |
| * accounted by later btrfs_qgroup_inherit(). |
| */ |
| btrfs_set_skip_qgroup(trans, objectid); |
| |
| btrfs_reloc_pre_snapshot(pending, &to_reserve); |
| |
| if (to_reserve > 0) { |
| pending->error = btrfs_block_rsv_add(fs_info, |
| &pending->block_rsv, |
| to_reserve, |
| BTRFS_RESERVE_NO_FLUSH); |
| if (pending->error) |
| goto clear_skip_qgroup; |
| } |
| |
| key.objectid = objectid; |
| key.offset = (u64)-1; |
| key.type = BTRFS_ROOT_ITEM_KEY; |
| |
| rsv = trans->block_rsv; |
| trans->block_rsv = &pending->block_rsv; |
| trans->bytes_reserved = trans->block_rsv->reserved; |
| trace_btrfs_space_reservation(fs_info, "transaction", |
| trans->transid, |
| trans->bytes_reserved, 1); |
| dentry = pending->dentry; |
| parent_inode = pending->dir; |
| parent_root = BTRFS_I(parent_inode)->root; |
| ret = record_root_in_trans(trans, parent_root, 0); |
| if (ret) |
| goto fail; |
| cur_time = current_time(parent_inode); |
| |
| /* |
| * insert the directory item |
| */ |
| ret = btrfs_set_inode_index(BTRFS_I(parent_inode), &index); |
| BUG_ON(ret); /* -ENOMEM */ |
| |
| /* check if there is a file/dir which has the same name. */ |
| dir_item = btrfs_lookup_dir_item(NULL, parent_root, path, |
| btrfs_ino(BTRFS_I(parent_inode)), |
| dentry->d_name.name, |
| dentry->d_name.len, 0); |
| if (dir_item != NULL && !IS_ERR(dir_item)) { |
| pending->error = -EEXIST; |
| goto dir_item_existed; |
| } else if (IS_ERR(dir_item)) { |
| ret = PTR_ERR(dir_item); |
| btrfs_abort_transaction(trans, ret); |
| goto fail; |
| } |
| btrfs_release_path(path); |
| |
| /* |
| * pull in the delayed directory update |
| * and the delayed inode item |
| * otherwise we corrupt the FS during |
| * snapshot |
| */ |
| ret = btrfs_run_delayed_items(trans); |
| if (ret) { /* Transaction aborted */ |
| btrfs_abort_transaction(trans, ret); |
| goto fail; |
| } |
| |
| ret = record_root_in_trans(trans, root, 0); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto fail; |
| } |
| btrfs_set_root_last_snapshot(&root->root_item, trans->transid); |
| memcpy(new_root_item, &root->root_item, sizeof(*new_root_item)); |
| btrfs_check_and_init_root_item(new_root_item); |
| |
| root_flags = btrfs_root_flags(new_root_item); |
| if (pending->readonly) |
| root_flags |= BTRFS_ROOT_SUBVOL_RDONLY; |
| else |
| root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY; |
| btrfs_set_root_flags(new_root_item, root_flags); |
| |
| btrfs_set_root_generation_v2(new_root_item, |
| trans->transid); |
| generate_random_guid(new_root_item->uuid); |
| memcpy(new_root_item->parent_uuid, root->root_item.uuid, |
| BTRFS_UUID_SIZE); |
| if (!(root_flags & BTRFS_ROOT_SUBVOL_RDONLY)) { |
| memset(new_root_item->received_uuid, 0, |
| sizeof(new_root_item->received_uuid)); |
| memset(&new_root_item->stime, 0, sizeof(new_root_item->stime)); |
| memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime)); |
| btrfs_set_root_stransid(new_root_item, 0); |
| btrfs_set_root_rtransid(new_root_item, 0); |
| } |
| btrfs_set_stack_timespec_sec(&new_root_item->otime, cur_time.tv_sec); |
| btrfs_set_stack_timespec_nsec(&new_root_item->otime, cur_time.tv_nsec); |
| btrfs_set_root_otransid(new_root_item, trans->transid); |
| |
| old = btrfs_lock_root_node(root); |
| ret = btrfs_cow_block(trans, root, old, NULL, 0, &old, |
| BTRFS_NESTING_COW); |
| if (ret) { |
| btrfs_tree_unlock(old); |
| free_extent_buffer(old); |
| btrfs_abort_transaction(trans, ret); |
| goto fail; |
| } |
| |
| ret = btrfs_copy_root(trans, root, old, &tmp, objectid); |
| /* clean up in any case */ |
| btrfs_tree_unlock(old); |
| free_extent_buffer(old); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto fail; |
| } |
| /* see comments in should_cow_block() */ |
| set_bit(BTRFS_ROOT_FORCE_COW, &root->state); |
| smp_wmb(); |
| |
| btrfs_set_root_node(new_root_item, tmp); |
| /* record when the snapshot was created in key.offset */ |
| key.offset = trans->transid; |
| ret = btrfs_insert_root(trans, tree_root, &key, new_root_item); |
| btrfs_tree_unlock(tmp); |
| free_extent_buffer(tmp); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto fail; |
| } |
| |
| /* |
| * insert root back/forward references |
| */ |
| ret = btrfs_add_root_ref(trans, objectid, |
| parent_root->root_key.objectid, |
| btrfs_ino(BTRFS_I(parent_inode)), index, |
| dentry->d_name.name, dentry->d_name.len); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto fail; |
| } |
| |
| key.offset = (u64)-1; |
| pending->snap = btrfs_get_new_fs_root(fs_info, objectid, pending->anon_dev); |
| if (IS_ERR(pending->snap)) { |
| ret = PTR_ERR(pending->snap); |
| pending->snap = NULL; |
| btrfs_abort_transaction(trans, ret); |
| goto fail; |
| } |
| |
| ret = btrfs_reloc_post_snapshot(trans, pending); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto fail; |
| } |
| |
| /* |
| * Do special qgroup accounting for snapshot, as we do some qgroup |
| * snapshot hack to do fast snapshot. |
| * To co-operate with that hack, we do hack again. |
| * Or snapshot will be greatly slowed down by a subtree qgroup rescan |
| */ |
| ret = qgroup_account_snapshot(trans, root, parent_root, |
| pending->inherit, objectid); |
| if (ret < 0) |
| goto fail; |
| |
| ret = btrfs_insert_dir_item(trans, dentry->d_name.name, |
| dentry->d_name.len, BTRFS_I(parent_inode), |
| &key, BTRFS_FT_DIR, index); |
| /* We have check then name at the beginning, so it is impossible. */ |
| BUG_ON(ret == -EEXIST || ret == -EOVERFLOW); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto fail; |
| } |
| |
| btrfs_i_size_write(BTRFS_I(parent_inode), parent_inode->i_size + |
| dentry->d_name.len * 2); |
| parent_inode->i_mtime = parent_inode->i_ctime = |
| current_time(parent_inode); |
| ret = btrfs_update_inode_fallback(trans, parent_root, BTRFS_I(parent_inode)); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto fail; |
| } |
| ret = btrfs_uuid_tree_add(trans, new_root_item->uuid, |
| BTRFS_UUID_KEY_SUBVOL, |
| objectid); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto fail; |
| } |
| if (!btrfs_is_empty_uuid(new_root_item->received_uuid)) { |
| ret = btrfs_uuid_tree_add(trans, new_root_item->received_uuid, |
| BTRFS_UUID_KEY_RECEIVED_SUBVOL, |
| objectid); |
| if (ret && ret != -EEXIST) { |
| btrfs_abort_transaction(trans, ret); |
| goto fail; |
| } |
| } |
| |
| fail: |
| pending->error = ret; |
| dir_item_existed: |
| trans->block_rsv = rsv; |
| trans->bytes_reserved = 0; |
| clear_skip_qgroup: |
| btrfs_clear_skip_qgroup(trans); |
| no_free_objectid: |
| kfree(new_root_item); |
| pending->root_item = NULL; |
| btrfs_free_path(path); |
| pending->path = NULL; |
| |
| return ret; |
| } |
| |
| /* |
| * create all the snapshots we've scheduled for creation |
| */ |
| static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_pending_snapshot *pending, *next; |
| struct list_head *head = &trans->transaction->pending_snapshots; |
| int ret = 0; |
| |
| list_for_each_entry_safe(pending, next, head, list) { |
| list_del(&pending->list); |
| ret = create_pending_snapshot(trans, pending); |
| if (ret) |
| break; |
| } |
| return ret; |
| } |
| |
| static void update_super_roots(struct btrfs_fs_info *fs_info) |
| { |
| struct btrfs_root_item *root_item; |
| struct btrfs_super_block *super; |
| |
| super = fs_info->super_copy; |
| |
| root_item = &fs_info->chunk_root->root_item; |
| super->chunk_root = root_item->bytenr; |
| super->chunk_root_generation = root_item->generation; |
| super->chunk_root_level = root_item->level; |
| |
| root_item = &fs_info->tree_root->root_item; |
| super->root = root_item->bytenr; |
| super->generation = root_item->generation; |
| super->root_level = root_item->level; |
| if (btrfs_test_opt(fs_info, SPACE_CACHE)) |
| super->cache_generation = root_item->generation; |
| else if (test_bit(BTRFS_FS_CLEANUP_SPACE_CACHE_V1, &fs_info->flags)) |
| super->cache_generation = 0; |
| if (test_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags)) |
| super->uuid_tree_generation = root_item->generation; |
| |
| if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) { |
| root_item = &fs_info->block_group_root->root_item; |
| |
| super->block_group_root = root_item->bytenr; |
| super->block_group_root_generation = root_item->generation; |
| super->block_group_root_level = root_item->level; |
| } |
| } |
| |
| int btrfs_transaction_in_commit(struct btrfs_fs_info *info) |
| { |
| struct btrfs_transaction *trans; |
| int ret = 0; |
| |
| spin_lock(&info->trans_lock); |
| trans = info->running_transaction; |
| if (trans) |
| ret = (trans->state >= TRANS_STATE_COMMIT_START); |
| spin_unlock(&info->trans_lock); |
| return ret; |
| } |
| |
| int btrfs_transaction_blocked(struct btrfs_fs_info *info) |
| { |
| struct btrfs_transaction *trans; |
| int ret = 0; |
| |
| spin_lock(&info->trans_lock); |
| trans = info->running_transaction; |
| if (trans) |
| ret = is_transaction_blocked(trans); |
| spin_unlock(&info->trans_lock); |
| return ret; |
| } |
| |
| void btrfs_commit_transaction_async(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_transaction *cur_trans; |
| |
| /* Kick the transaction kthread. */ |
| set_bit(BTRFS_FS_COMMIT_TRANS, &fs_info->flags); |
| wake_up_process(fs_info->transaction_kthread); |
| |
| /* take transaction reference */ |
| cur_trans = trans->transaction; |
| refcount_inc(&cur_trans->use_count); |
| |
| btrfs_end_transaction(trans); |
| |
| /* |
| * Wait for the current transaction commit to start and block |
| * subsequent transaction joins |
| */ |
| wait_event(fs_info->transaction_blocked_wait, |
| cur_trans->state >= TRANS_STATE_COMMIT_START || |
| TRANS_ABORTED(cur_trans)); |
| btrfs_put_transaction(cur_trans); |
| } |
| |
| static void cleanup_transaction(struct btrfs_trans_handle *trans, int err) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_transaction *cur_trans = trans->transaction; |
| |
| WARN_ON(refcount_read(&trans->use_count) > 1); |
| |
| btrfs_abort_transaction(trans, err); |
| |
| spin_lock(&fs_info->trans_lock); |
| |
| /* |
| * If the transaction is removed from the list, it means this |
| * transaction has been committed successfully, so it is impossible |
| * to call the cleanup function. |
| */ |
| BUG_ON(list_empty(&cur_trans->list)); |
| |
| if (cur_trans == fs_info->running_transaction) { |
| cur_trans->state = TRANS_STATE_COMMIT_DOING; |
| spin_unlock(&fs_info->trans_lock); |
| wait_event(cur_trans->writer_wait, |
| atomic_read(&cur_trans->num_writers) == 1); |
| |
| spin_lock(&fs_info->trans_lock); |
| } |
| |
| /* |
| * Now that we know no one else is still using the transaction we can |
| * remove the transaction from the list of transactions. This avoids |
| * the transaction kthread from cleaning up the transaction while some |
| * other task is still using it, which could result in a use-after-free |
| * on things like log trees, as it forces the transaction kthread to |
| * wait for this transaction to be cleaned up by us. |
| */ |
| list_del_init(&cur_trans->list); |
| |
| spin_unlock(&fs_info->trans_lock); |
| |
| btrfs_cleanup_one_transaction(trans->transaction, fs_info); |
| |
| spin_lock(&fs_info->trans_lock); |
| if (cur_trans == fs_info->running_transaction) |
| fs_info->running_transaction = NULL; |
| spin_unlock(&fs_info->trans_lock); |
| |
| if (trans->type & __TRANS_FREEZABLE) |
| sb_end_intwrite(fs_info->sb); |
| btrfs_put_transaction(cur_trans); |
| btrfs_put_transaction(cur_trans); |
| |
| trace_btrfs_transaction_commit(fs_info); |
| |
| if (current->journal_info == trans) |
| current->journal_info = NULL; |
| btrfs_scrub_cancel(fs_info); |
| |
| kmem_cache_free(btrfs_trans_handle_cachep, trans); |
| } |
| |
| /* |
| * Release reserved delayed ref space of all pending block groups of the |
| * transaction and remove them from the list |
| */ |
| static void btrfs_cleanup_pending_block_groups(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_block_group *block_group, *tmp; |
| |
| list_for_each_entry_safe(block_group, tmp, &trans->new_bgs, bg_list) { |
| btrfs_delayed_refs_rsv_release(fs_info, 1); |
| list_del_init(&block_group->bg_list); |
| } |
| } |
| |
| static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info) |
| { |
| /* |
| * We use try_to_writeback_inodes_sb() here because if we used |
| * btrfs_start_delalloc_roots we would deadlock with fs freeze. |
| * Currently are holding the fs freeze lock, if we do an async flush |
| * we'll do btrfs_join_transaction() and deadlock because we need to |
| * wait for the fs freeze lock. Using the direct flushing we benefit |
| * from already being in a transaction and our join_transaction doesn't |
| * have to re-take the fs freeze lock. |
| * |
| * Note that try_to_writeback_inodes_sb() will only trigger writeback |
| * if it can read lock sb->s_umount. It will always be able to lock it, |
| * except when the filesystem is being unmounted or being frozen, but in |
| * those cases sync_filesystem() is called, which results in calling |
| * writeback_inodes_sb() while holding a write lock on sb->s_umount. |
| * Note that we don't call writeback_inodes_sb() directly, because it |
| * will emit a warning if sb->s_umount is not locked. |
| */ |
| if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) |
| try_to_writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); |
| return 0; |
| } |
| |
| static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info) |
| { |
| if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) |
| btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); |
| } |
| |
| /* |
| * Add a pending snapshot associated with the given transaction handle to the |
| * respective handle. This must be called after the transaction commit started |
| * and while holding fs_info->trans_lock. |
| * This serves to guarantee a caller of btrfs_commit_transaction() that it can |
| * safely free the pending snapshot pointer in case btrfs_commit_transaction() |
| * returns an error. |
| */ |
| static void add_pending_snapshot(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_transaction *cur_trans = trans->transaction; |
| |
| if (!trans->pending_snapshot) |
| return; |
| |
| lockdep_assert_held(&trans->fs_info->trans_lock); |
| ASSERT(cur_trans->state >= TRANS_STATE_COMMIT_START); |
| |
| list_add(&trans->pending_snapshot->list, &cur_trans->pending_snapshots); |
| } |
| |
| int btrfs_commit_transaction(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_transaction *cur_trans = trans->transaction; |
| struct btrfs_transaction *prev_trans = NULL; |
| int ret; |
| |
| ASSERT(refcount_read(&trans->use_count) == 1); |
| |
| /* Stop the commit early if ->aborted is set */ |
| if (TRANS_ABORTED(cur_trans)) { |
| ret = cur_trans->aborted; |
| btrfs_end_transaction(trans); |
| return ret; |
| } |
| |
| btrfs_trans_release_metadata(trans); |
| trans->block_rsv = NULL; |
| |
| /* |
| * We only want one transaction commit doing the flushing so we do not |
| * waste a bunch of time on lock contention on the extent root node. |
| */ |
| if (!test_and_set_bit(BTRFS_DELAYED_REFS_FLUSHING, |
| &cur_trans->delayed_refs.flags)) { |
| /* |
| * Make a pass through all the delayed refs we have so far. |
| * Any running threads may add more while we are here. |
| */ |
| ret = btrfs_run_delayed_refs(trans, 0); |
| if (ret) { |
| btrfs_end_transaction(trans); |
| return ret; |
| } |
| } |
| |
| btrfs_create_pending_block_groups(trans); |
| |
| if (!test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &cur_trans->flags)) { |
| int run_it = 0; |
| |
| /* this mutex is also taken before trying to set |
| * block groups readonly. We need to make sure |
| * that nobody has set a block group readonly |
| * after a extents from that block group have been |
| * allocated for cache files. btrfs_set_block_group_ro |
| * will wait for the transaction to commit if it |
| * finds BTRFS_TRANS_DIRTY_BG_RUN set. |
| * |
| * The BTRFS_TRANS_DIRTY_BG_RUN flag is also used to make sure |
| * only one process starts all the block group IO. It wouldn't |
| * hurt to have more than one go through, but there's no |
| * real advantage to it either. |
| */ |
| mutex_lock(&fs_info->ro_block_group_mutex); |
| if (!test_and_set_bit(BTRFS_TRANS_DIRTY_BG_RUN, |
| &cur_trans->flags)) |
| run_it = 1; |
| mutex_unlock(&fs_info->ro_block_group_mutex); |
| |
| if (run_it) { |
| ret = btrfs_start_dirty_block_groups(trans); |
| if (ret) { |
| btrfs_end_transaction(trans); |
| return ret; |
| } |
| } |
| } |
| |
| spin_lock(&fs_info->trans_lock); |
| if (cur_trans->state >= TRANS_STATE_COMMIT_START) { |
| enum btrfs_trans_state want_state = TRANS_STATE_COMPLETED; |
| |
| add_pending_snapshot(trans); |
| |
| spin_unlock(&fs_info->trans_lock); |
| refcount_inc(&cur_trans->use_count); |
| |
| if (trans->in_fsync) |
| want_state = TRANS_STATE_SUPER_COMMITTED; |
| ret = btrfs_end_transaction(trans); |
| wait_for_commit(cur_trans, want_state); |
| |
| if (TRANS_ABORTED(cur_trans)) |
| ret = cur_trans->aborted; |
| |
| btrfs_put_transaction(cur_trans); |
| |
| return ret; |
| } |
| |
| cur_trans->state = TRANS_STATE_COMMIT_START; |
| wake_up(&fs_info->transaction_blocked_wait); |
| |
| if (cur_trans->list.prev != &fs_info->trans_list) { |
| enum btrfs_trans_state want_state = TRANS_STATE_COMPLETED; |
| |
| if (trans->in_fsync) |
| want_state = TRANS_STATE_SUPER_COMMITTED; |
| |
| prev_trans = list_entry(cur_trans->list.prev, |
| struct btrfs_transaction, list); |
| if (prev_trans->state < want_state) { |
| refcount_inc(&prev_trans->use_count); |
| spin_unlock(&fs_info->trans_lock); |
| |
| wait_for_commit(prev_trans, want_state); |
| |
| ret = READ_ONCE(prev_trans->aborted); |
| |
| btrfs_put_transaction(prev_trans); |
| if (ret) |
| goto cleanup_transaction; |
| } else { |
| spin_unlock(&fs_info->trans_lock); |
| } |
| } else { |
| spin_unlock(&fs_info->trans_lock); |
| /* |
| * The previous transaction was aborted and was already removed |
| * from the list of transactions at fs_info->trans_list. So we |
| * abort to prevent writing a new superblock that reflects a |
| * corrupt state (pointing to trees with unwritten nodes/leafs). |
| */ |
| if (BTRFS_FS_ERROR(fs_info)) { |
| ret = -EROFS; |
| goto cleanup_transaction; |
| } |
| } |
| |
| extwriter_counter_dec(cur_trans, trans->type); |
| |
| ret = btrfs_start_delalloc_flush(fs_info); |
| if (ret) |
| goto cleanup_transaction; |
| |
| ret = btrfs_run_delayed_items(trans); |
| if (ret) |
| goto cleanup_transaction; |
| |
| wait_event(cur_trans->writer_wait, |
| extwriter_counter_read(cur_trans) == 0); |
| |
| /* some pending stuffs might be added after the previous flush. */ |
| ret = btrfs_run_delayed_items(trans); |
| if (ret) |
| goto cleanup_transaction; |
| |
| btrfs_wait_delalloc_flush(fs_info); |
| |
| /* |
| * Wait for all ordered extents started by a fast fsync that joined this |
| * transaction. Otherwise if this transaction commits before the ordered |
| * extents complete we lose logged data after a power failure. |
| */ |
| wait_event(cur_trans->pending_wait, |
| atomic_read(&cur_trans->pending_ordered) == 0); |
| |
| btrfs_scrub_pause(fs_info); |
| /* |
| * Ok now we need to make sure to block out any other joins while we |
| * commit the transaction. We could have started a join before setting |
| * COMMIT_DOING so make sure to wait for num_writers to == 1 again. |
| */ |
| spin_lock(&fs_info->trans_lock); |
| add_pending_snapshot(trans); |
| cur_trans->state = TRANS_STATE_COMMIT_DOING; |
| spin_unlock(&fs_info->trans_lock); |
| wait_event(cur_trans->writer_wait, |
| atomic_read(&cur_trans->num_writers) == 1); |
| |
| /* |
| * We've started the commit, clear the flag in case we were triggered to |
| * do an async commit but somebody else started before the transaction |
| * kthread could do the work. |
| */ |
| clear_bit(BTRFS_FS_COMMIT_TRANS, &fs_info->flags); |
| |
| if (TRANS_ABORTED(cur_trans)) { |
| ret = cur_trans->aborted; |
| goto scrub_continue; |
| } |
| /* |
| * the reloc mutex makes sure that we stop |
| * the balancing code from coming in and moving |
| * extents around in the middle of the commit |
| */ |
| mutex_lock(&fs_info->reloc_mutex); |
| |
| /* |
| * We needn't worry about the delayed items because we will |
| * deal with them in create_pending_snapshot(), which is the |
| * core function of the snapshot creation. |
| */ |
| ret = create_pending_snapshots(trans); |
| if (ret) |
| goto unlock_reloc; |
| |
| /* |
| * We insert the dir indexes of the snapshots and update the inode |
| * of the snapshots' parents after the snapshot creation, so there |
| * are some delayed items which are not dealt with. Now deal with |
| * them. |
| * |
| * We needn't worry that this operation will corrupt the snapshots, |
| * because all the tree which are snapshoted will be forced to COW |
| * the nodes and leaves. |
| */ |
| ret = btrfs_run_delayed_items(trans); |
| if (ret) |
| goto unlock_reloc; |
| |
| ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); |
| if (ret) |
| goto unlock_reloc; |
| |
| /* |
| * make sure none of the code above managed to slip in a |
| * delayed item |
| */ |
| btrfs_assert_delayed_root_empty(fs_info); |
| |
| WARN_ON(cur_trans != trans->transaction); |
| |
| ret = commit_fs_roots(trans); |
| if (ret) |
| goto unlock_reloc; |
| |
| /* |
| * Since the transaction is done, we can apply the pending changes |
| * before the next transaction. |
| */ |
| btrfs_apply_pending_changes(fs_info); |
| |
| /* commit_fs_roots gets rid of all the tree log roots, it is now |
| * safe to free the root of tree log roots |
| */ |
| btrfs_free_log_root_tree(trans, fs_info); |
| |
| /* |
| * Since fs roots are all committed, we can get a quite accurate |
| * new_roots. So let's do quota accounting. |
| */ |
| ret = btrfs_qgroup_account_extents(trans); |
| if (ret < 0) |
| goto unlock_reloc; |
| |
| ret = commit_cowonly_roots(trans); |
| if (ret) |
| goto unlock_reloc; |
| |
| /* |
| * The tasks which save the space cache and inode cache may also |
| * update ->aborted, check it. |
| */ |
| if (TRANS_ABORTED(cur_trans)) { |
| ret = cur_trans->aborted; |
| goto unlock_reloc; |
| } |
| |
| cur_trans = fs_info->running_transaction; |
| |
| btrfs_set_root_node(&fs_info->tree_root->root_item, |
| fs_info->tree_root->node); |
| list_add_tail(&fs_info->tree_root->dirty_list, |
| &cur_trans->switch_commits); |
| |
| btrfs_set_root_node(&fs_info->chunk_root->root_item, |
| fs_info->chunk_root->node); |
| list_add_tail(&fs_info->chunk_root->dirty_list, |
| &cur_trans->switch_commits); |
| |
| if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) { |
| btrfs_set_root_node(&fs_info->block_group_root->root_item, |
| fs_info->block_group_root->node); |
| list_add_tail(&fs_info->block_group_root->dirty_list, |
| &cur_trans->switch_commits); |
| } |
| |
| switch_commit_roots(trans); |
| |
| ASSERT(list_empty(&cur_trans->dirty_bgs)); |
| ASSERT(list_empty(&cur_trans->io_bgs)); |
| update_super_roots(fs_info); |
| |
| btrfs_set_super_log_root(fs_info->super_copy, 0); |
| btrfs_set_super_log_root_level(fs_info->super_copy, 0); |
| memcpy(fs_info->super_for_commit, fs_info->super_copy, |
| sizeof(*fs_info->super_copy)); |
| |
| btrfs_commit_device_sizes(cur_trans); |
| |
| clear_bit(BTRFS_FS_LOG1_ERR, &fs_info->flags); |
| clear_bit(BTRFS_FS_LOG2_ERR, &fs_info->flags); |
| |
| btrfs_trans_release_chunk_metadata(trans); |
| |
| /* |
| * Before changing the transaction state to TRANS_STATE_UNBLOCKED and |
| * setting fs_info->running_transaction to NULL, lock tree_log_mutex to |
| * make sure that before we commit our superblock, no other task can |
| * start a new transaction and commit a log tree before we commit our |
| * superblock. Anyone trying to commit a log tree locks this mutex before |
| * writing its superblock. |
| */ |
| mutex_lock(&fs_info->tree_log_mutex); |
| |
| spin_lock(&fs_info->trans_lock); |
| cur_trans->state = TRANS_STATE_UNBLOCKED; |
| fs_info->running_transaction = NULL; |
| spin_unlock(&fs_info->trans_lock); |
| mutex_unlock(&fs_info->reloc_mutex); |
| |
| wake_up(&fs_info->transaction_wait); |
| |
| ret = btrfs_write_and_wait_transaction(trans); |
| if (ret) { |
| btrfs_handle_fs_error(fs_info, ret, |
| "Error while writing out transaction"); |
| mutex_unlock(&fs_info->tree_log_mutex); |
| goto scrub_continue; |
| } |
| |
| /* |
| * At this point, we should have written all the tree blocks allocated |
| * in this transaction. So it's now safe to free the redirtyied extent |
| * buffers. |
| */ |
| btrfs_free_redirty_list(cur_trans); |
| |
| ret = write_all_supers(fs_info, 0); |
| /* |
| * the super is written, we can safely allow the tree-loggers |
| * to go about their business |
| */ |
| mutex_unlock(&fs_info->tree_log_mutex); |
| if (ret) |
| goto scrub_continue; |
| |
| /* |
| * We needn't acquire the lock here because there is no other task |
| * which can change it. |
| */ |
| cur_trans->state = TRANS_STATE_SUPER_COMMITTED; |
| wake_up(&cur_trans->commit_wait); |
| |
| btrfs_finish_extent_commit(trans); |
| |
| if (test_bit(BTRFS_TRANS_HAVE_FREE_BGS, &cur_trans->flags)) |
| btrfs_clear_space_info_full(fs_info); |
| |
| fs_info->last_trans_committed = cur_trans->transid; |
| /* |
| * We needn't acquire the lock here because there is no other task |
| * which can change it. |
| */ |
| cur_trans->state = TRANS_STATE_COMPLETED; |
| wake_up(&cur_trans->commit_wait); |
| |
| spin_lock(&fs_info->trans_lock); |
| list_del_init(&cur_trans->list); |
| spin_unlock(&fs_info->trans_lock); |
| |
| btrfs_put_transaction(cur_trans); |
| btrfs_put_transaction(cur_trans); |
| |
| if (trans->type & __TRANS_FREEZABLE) |
| sb_end_intwrite(fs_info->sb); |
| |
| trace_btrfs_transaction_commit(fs_info); |
| |
| btrfs_scrub_continue(fs_info); |
| |
| if (current->journal_info == trans) |
| current->journal_info = NULL; |
| |
| kmem_cache_free(btrfs_trans_handle_cachep, trans); |
| |
| return ret; |
| |
| unlock_reloc: |
| mutex_unlock(&fs_info->reloc_mutex); |
| scrub_continue: |
| btrfs_scrub_continue(fs_info); |
| cleanup_transaction: |
| btrfs_trans_release_metadata(trans); |
| btrfs_cleanup_pending_block_groups(trans); |
| btrfs_trans_release_chunk_metadata(trans); |
| trans->block_rsv = NULL; |
| btrfs_warn(fs_info, "Skipping commit of aborted transaction."); |
| if (current->journal_info == trans) |
| current->journal_info = NULL; |
| cleanup_transaction(trans, ret); |
| |
| return ret; |
| } |
| |
| /* |
| * return < 0 if error |
| * 0 if there are no more dead_roots at the time of call |
| * 1 there are more to be processed, call me again |
| * |
| * The return value indicates there are certainly more snapshots to delete, but |
| * if there comes a new one during processing, it may return 0. We don't mind, |
| * because btrfs_commit_super will poke cleaner thread and it will process it a |
| * few seconds later. |
| */ |
| int btrfs_clean_one_deleted_snapshot(struct btrfs_fs_info *fs_info) |
| { |
| struct btrfs_root *root; |
| int ret; |
| |
| spin_lock(&fs_info->trans_lock); |
| if (list_empty(&fs_info->dead_roots)) { |
| spin_unlock(&fs_info->trans_lock); |
| return 0; |
| } |
| root = list_first_entry(&fs_info->dead_roots, |
| struct btrfs_root, root_list); |
| list_del_init(&root->root_list); |
| spin_unlock(&fs_info->trans_lock); |
| |
| btrfs_debug(fs_info, "cleaner removing %llu", root->root_key.objectid); |
| |
| btrfs_kill_all_delayed_nodes(root); |
| |
| if (btrfs_header_backref_rev(root->node) < |
| BTRFS_MIXED_BACKREF_REV) |
| ret = btrfs_drop_snapshot(root, 0, 0); |
| else |
| ret = btrfs_drop_snapshot(root, 1, 0); |
| |
| btrfs_put_root(root); |
| return (ret < 0) ? 0 : 1; |
| } |
| |
| void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info) |
| { |
| unsigned long prev; |
| unsigned long bit; |
| |
| prev = xchg(&fs_info->pending_changes, 0); |
| if (!prev) |
| return; |
| |
| bit = 1 << BTRFS_PENDING_COMMIT; |
| if (prev & bit) |
| btrfs_debug(fs_info, "pending commit done"); |
| prev &= ~bit; |
| |
| if (prev) |
| btrfs_warn(fs_info, |
| "unknown pending changes left 0x%lx, ignoring", prev); |
| } |