ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/fs/btrfs/transaction.c b/marvell/linux/fs/btrfs/transaction.c
new file mode 100644
index 0000000..1d25bf0
--- /dev/null
+++ b/marvell/linux/fs/btrfs/transaction.c
@@ -0,0 +1,2409 @@
+// 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 "inode-map.h"
+#include "volumes.h"
+#include "dev-replace.h"
+#include "qgroup.h"
+#include "block-group.h"
+#include "space-info.h"
+
+#define BTRFS_ROOT_TRANS_TAG 0
+
+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_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;
+
+ cache = list_first_entry(&transaction->deleted_bgs,
+ struct btrfs_block_group_cache,
+ bg_list);
+ list_del_init(&cache->bg_list);
+ btrfs_put_block_group_trimming(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;
+
+ down_write(&fs_info->commit_root_sem);
+ 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);
+ if (is_fstree(root->root_key.objectid))
+ btrfs_unpin_free_ino(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);
+ 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 all the new block groups attached to the transaction
+ * handle have been created (btrfs_create_pending_block_groups()).
+ */
+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;
+
+ WARN_ON_ONCE(!list_empty(&trans->new_bgs));
+
+ btrfs_block_rsv_release(fs_info, &fs_info->chunk_block_rsv,
+ trans->chunk_bytes_reserved);
+ 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 (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
+ 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 or TRANS_JOIN_NOSTART, we just want to catch the
+ * current transaction, and commit it. If there is no transaction, just
+ * return ENOENT.
+ */
+ if (type == TRANS_ATTACH || type == TRANS_JOIN_NOSTART)
+ 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 (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
+ spin_unlock(&fs_info->trans_lock);
+ kfree(cur_trans);
+ return -EROFS;
+ }
+
+ cur_trans->fs_info = fs_info;
+ 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);
+ 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);
+ 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 reference
+ * counted 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;
+
+ if ((test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
+ root->last_trans < trans->transid) || force) {
+ WARN_ON(root == fs_info->extent_root);
+ 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_radix_lock);
+ if (root->last_trans == trans->transid && !force) {
+ spin_unlock(&fs_info->fs_roots_radix_lock);
+ return 0;
+ }
+ radix_tree_tag_set(&fs_info->fs_roots_radix,
+ (unsigned long)root->root_key.objectid,
+ BTRFS_ROOT_TRANS_TAG);
+ spin_unlock(&fs_info->fs_roots_radix_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
+ */
+ btrfs_init_reloc_root(trans, root);
+ smp_mb__before_atomic();
+ clear_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state);
+ }
+ return 0;
+}
+
+
+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 */
+ spin_lock(&fs_info->fs_roots_radix_lock);
+ radix_tree_tag_clear(&fs_info->fs_roots_radix,
+ (unsigned long)root->root_key.objectid,
+ BTRFS_ROOT_TRANS_TAG);
+ spin_unlock(&fs_info->fs_roots_radix_lock);
+}
+
+int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+
+ if (!test_bit(BTRFS_ROOT_REF_COWS, &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);
+ record_root_in_trans(trans, root, 0);
+ mutex_unlock(&fs_info->reloc_mutex);
+
+ return 0;
+}
+
+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_REF_COWS, &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;
+
+ /* Send isn't supposed to start transactions. */
+ ASSERT(current->journal_info != BTRFS_SEND_TRANS_STUB);
+
+ if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
+ 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(root, 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;
+ h->root = root;
+ refcount_set(&h->use_count, 1);
+ h->fs_info = root->fs_info;
+
+ h->type = type;
+ h->can_flush_pending_bgs = true;
+ 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.
+ */
+ btrfs_record_root_in_trans(h, root);
+
+ 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);
+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_nolock(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)) {
+ int ret;
+
+ ret = btrfs_wait_for_commit(root->fs_info, 0);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+
+ return trans;
+}
+
+/* wait for a transaction commit to be fully complete */
+static noinline void wait_for_commit(struct btrfs_transaction *commit)
+{
+ wait_event(commit->commit_wait, commit->state == TRANS_STATE_COMPLETED);
+}
+
+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);
+ ret = cur_trans->aborted;
+ btrfs_put_transaction(cur_trans);
+out:
+ return ret;
+}
+
+void btrfs_throttle(struct btrfs_fs_info *fs_info)
+{
+ wait_current_trans(fs_info);
+}
+
+static int 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 1;
+
+ return !!btrfs_block_rsv_check(&fs_info->global_block_rsv, 5);
+}
+
+int btrfs_should_end_transaction(struct btrfs_trans_handle *trans)
+{
+ struct btrfs_transaction *cur_trans = trans->transaction;
+
+ smp_mb();
+ if (cur_trans->state >= TRANS_STATE_COMMIT_START ||
+ cur_trans->delayed_refs.flushing)
+ return 1;
+
+ 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);
+ 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) ||
+ test_bit(BTRFS_FS_STATE_ERROR, &info->fs_state)) {
+ 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;
+}
+
+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;
+
+ eb = btrfs_lock_root_node(fs_info->tree_root);
+ ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL,
+ 0, &eb);
+ btrfs_tree_unlock(eb);
+ free_extent_buffer(eb);
+
+ if (ret)
+ return ret;
+
+ ret = btrfs_run_delayed_refs(trans, (unsigned long)-1);
+ 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;
+
+ /* run_qgroups might have added some more refs */
+ ret = btrfs_run_delayed_refs(trans, (unsigned long)-1);
+ 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);
+
+ if (root != fs_info->extent_root)
+ list_add_tail(&root->dirty_list,
+ &trans->transaction->switch_commits);
+ ret = update_cowonly_root(trans, root);
+ if (ret)
+ return ret;
+ 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;
+ ret = btrfs_run_delayed_refs(trans, (unsigned long)-1);
+ if (ret)
+ return ret;
+ }
+
+ if (!list_empty(&fs_info->dirty_cowonly_roots))
+ goto again;
+
+ list_add_tail(&fs_info->extent_root->dirty_list,
+ &trans->transaction->switch_commits);
+
+ /* 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;
+}
+
+/*
+ * 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))
+ list_add_tail(&root->root_list, &fs_info->dead_roots);
+ spin_unlock(&fs_info->trans_lock);
+}
+
+/*
+ * update all the cowonly tree roots on disk
+ */
+static noinline int commit_fs_roots(struct btrfs_trans_handle *trans)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ struct btrfs_root *gang[8];
+ int i;
+ int ret;
+
+ spin_lock(&fs_info->fs_roots_radix_lock);
+ while (1) {
+ ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix,
+ (void **)gang, 0,
+ ARRAY_SIZE(gang),
+ BTRFS_ROOT_TRANS_TAG);
+ if (ret == 0)
+ break;
+ for (i = 0; i < ret; i++) {
+ struct btrfs_root *root = gang[i];
+ int ret2;
+
+ radix_tree_tag_clear(&fs_info->fs_roots_radix,
+ (unsigned long)root->root_key.objectid,
+ BTRFS_ROOT_TRANS_TAG);
+ btrfs_qgroup_free_meta_all_pertrans(root);
+ spin_unlock(&fs_info->fs_roots_radix_lock);
+
+ btrfs_free_log(trans, root);
+ btrfs_update_reloc_root(trans, root);
+
+ btrfs_save_ino_cache(root, trans);
+
+ /* 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);
+ }
+
+ ret2 = btrfs_update_root(trans, fs_info->tree_root,
+ &root->root_key,
+ &root->root_item);
+ if (ret2)
+ return ret2;
+ spin_lock(&fs_info->fs_roots_radix_lock);
+ }
+ }
+ spin_unlock(&fs_info->fs_roots_radix_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.
+ */
+ record_root_in_trans(trans, src, 1);
+
+ /*
+ * We are going to commit transaction, see btrfs_commit_transaction()
+ * comment for reason locking tree_log_mutex
+ */
+ mutex_lock(&fs_info->tree_log_mutex);
+
+ 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:
+ mutex_unlock(&fs_info->tree_log_mutex);
+
+ /*
+ * 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)
+ 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;
+ uuid_le new_uuid;
+
+ ASSERT(pending->path);
+ path = pending->path;
+
+ ASSERT(pending->root_item);
+ new_root_item = pending->root_item;
+
+ pending->error = btrfs_find_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(root,
+ &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;
+ record_root_in_trans(trans, parent_root, 0);
+
+ 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;
+ }
+
+ record_root_in_trans(trans, root, 0);
+ 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);
+ uuid_le_gen(&new_uuid);
+ memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
+ 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);
+ if (ret) {
+ btrfs_tree_unlock(old);
+ free_extent_buffer(old);
+ btrfs_abort_transaction(trans, ret);
+ goto fail;
+ }
+
+ btrfs_set_lock_blocking_write(old);
+
+ 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_read_fs_root_no_name(fs_info, &key);
+ if (IS_ERR(pending->snap)) {
+ ret = PTR_ERR(pending->snap);
+ btrfs_abort_transaction(trans, ret);
+ goto fail;
+ }
+
+ ret = btrfs_reloc_post_snapshot(trans, pending);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ goto fail;
+ }
+
+ ret = btrfs_run_delayed_refs(trans, (unsigned long)-1);
+ 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, parent_inode);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ goto fail;
+ }
+ ret = btrfs_uuid_tree_add(trans, new_uuid.b, 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;
+ }
+ }
+
+ ret = btrfs_run_delayed_refs(trans, (unsigned long)-1);
+ if (ret) {
+ 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;
+ if (test_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags))
+ super->uuid_tree_generation = root_item->generation;
+}
+
+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;
+}
+
+/*
+ * wait for the current transaction commit to start and block subsequent
+ * transaction joins
+ */
+static void wait_current_trans_commit_start(struct btrfs_fs_info *fs_info,
+ struct btrfs_transaction *trans)
+{
+ wait_event(fs_info->transaction_blocked_wait,
+ trans->state >= TRANS_STATE_COMMIT_START ||
+ TRANS_ABORTED(trans));
+}
+
+/*
+ * wait for the current transaction to start and then become unblocked.
+ * caller holds ref.
+ */
+static void wait_current_trans_commit_start_and_unblock(
+ struct btrfs_fs_info *fs_info,
+ struct btrfs_transaction *trans)
+{
+ wait_event(fs_info->transaction_wait,
+ trans->state >= TRANS_STATE_UNBLOCKED ||
+ TRANS_ABORTED(trans));
+}
+
+/*
+ * commit transactions asynchronously. once btrfs_commit_transaction_async
+ * returns, any subsequent transaction will not be allowed to join.
+ */
+struct btrfs_async_commit {
+ struct btrfs_trans_handle *newtrans;
+ struct work_struct work;
+};
+
+static void do_async_commit(struct work_struct *work)
+{
+ struct btrfs_async_commit *ac =
+ container_of(work, struct btrfs_async_commit, work);
+
+ /*
+ * We've got freeze protection passed with the transaction.
+ * Tell lockdep about it.
+ */
+ if (ac->newtrans->type & __TRANS_FREEZABLE)
+ __sb_writers_acquired(ac->newtrans->fs_info->sb, SB_FREEZE_FS);
+
+ current->journal_info = ac->newtrans;
+
+ btrfs_commit_transaction(ac->newtrans);
+ kfree(ac);
+}
+
+int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
+ int wait_for_unblock)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ struct btrfs_async_commit *ac;
+ struct btrfs_transaction *cur_trans;
+
+ ac = kmalloc(sizeof(*ac), GFP_NOFS);
+ if (!ac)
+ return -ENOMEM;
+
+ INIT_WORK(&ac->work, do_async_commit);
+ ac->newtrans = btrfs_join_transaction(trans->root);
+ if (IS_ERR(ac->newtrans)) {
+ int err = PTR_ERR(ac->newtrans);
+ kfree(ac);
+ return err;
+ }
+
+ /* take transaction reference */
+ cur_trans = trans->transaction;
+ refcount_inc(&cur_trans->use_count);
+
+ btrfs_end_transaction(trans);
+
+ /*
+ * Tell lockdep we've released the freeze rwsem, since the
+ * async commit thread will be the one to unlock it.
+ */
+ if (ac->newtrans->type & __TRANS_FREEZABLE)
+ __sb_writers_release(fs_info->sb, SB_FREEZE_FS);
+
+ schedule_work(&ac->work);
+
+ /* wait for transaction to start and unblock */
+ if (wait_for_unblock)
+ wait_current_trans_commit_start_and_unblock(fs_info, cur_trans);
+ else
+ wait_current_trans_commit_start(fs_info, cur_trans);
+
+ if (current->journal_info == trans)
+ current->journal_info = NULL;
+
+ btrfs_put_transaction(cur_trans);
+ return 0;
+}
+
+
+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));
+
+ list_del_init(&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);
+ }
+ 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(trans->root);
+
+ 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_cache *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_trans_handle *trans)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+
+ /*
+ * We use 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.
+ */
+ if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) {
+ writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC);
+ } else {
+ struct btrfs_pending_snapshot *pending;
+ struct list_head *head = &trans->transaction->pending_snapshots;
+
+ /*
+ * Flush dellaloc for any root that is going to be snapshotted.
+ * This is done to avoid a corrupted version of files, in the
+ * snapshots, that had both buffered and direct IO writes (even
+ * if they were done sequentially) due to an unordered update of
+ * the inode's size on disk.
+ */
+ list_for_each_entry(pending, head, list) {
+ int ret;
+
+ ret = btrfs_start_delalloc_snapshot(pending->root);
+ if (ret)
+ return ret;
+ }
+ }
+ return 0;
+}
+
+static inline void btrfs_wait_delalloc_flush(struct btrfs_trans_handle *trans)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+
+ if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) {
+ btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
+ } else {
+ struct btrfs_pending_snapshot *pending;
+ struct list_head *head = &trans->transaction->pending_snapshots;
+
+ /*
+ * Wait for any dellaloc that we started previously for the roots
+ * that are going to be snapshotted. This is to avoid a corrupted
+ * version of files in the snapshots that had both buffered and
+ * direct IO writes (even if they were done sequentially).
+ */
+ list_for_each_entry(pending, head, list)
+ btrfs_wait_ordered_extents(pending->root,
+ U64_MAX, 0, U64_MAX);
+ }
+}
+
+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;
+
+ /*
+ * Some places just start a transaction to commit it. We need to make
+ * sure that if this commit fails that the abort code actually marks the
+ * transaction as failed, so set trans->dirty to make the abort code do
+ * the right thing.
+ */
+ trans->dirty = true;
+
+ /* 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;
+
+ /* make a pass through all the delayed refs we have so far
+ * any runnings procs may add more while we are here
+ */
+ ret = btrfs_run_delayed_refs(trans, 0);
+ if (ret) {
+ btrfs_end_transaction(trans);
+ return ret;
+ }
+
+ cur_trans = trans->transaction;
+
+ /*
+ * set the flushing flag so procs in this transaction have to
+ * start sending their work down.
+ */
+ cur_trans->delayed_refs.flushing = 1;
+ smp_wmb();
+
+ btrfs_create_pending_block_groups(trans);
+
+ ret = btrfs_run_delayed_refs(trans, 0);
+ if (ret) {
+ btrfs_end_transaction(trans);
+ return ret;
+ }
+
+ 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) {
+ spin_unlock(&fs_info->trans_lock);
+ refcount_inc(&cur_trans->use_count);
+ ret = btrfs_end_transaction(trans);
+
+ wait_for_commit(cur_trans);
+
+ 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) {
+ prev_trans = list_entry(cur_trans->list.prev,
+ struct btrfs_transaction, list);
+ if (prev_trans->state != TRANS_STATE_COMPLETED) {
+ refcount_inc(&prev_trans->use_count);
+ spin_unlock(&fs_info->trans_lock);
+
+ wait_for_commit(prev_trans);
+ 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 (test_bit(BTRFS_FS_STATE_TRANS_ABORTED, &fs_info->fs_state)) {
+ ret = -EROFS;
+ goto cleanup_transaction;
+ }
+ }
+
+ extwriter_counter_dec(cur_trans, trans->type);
+
+ ret = btrfs_start_delalloc_flush(trans);
+ 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(trans);
+
+ 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);
+ 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);
+
+ 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) {
+ mutex_unlock(&fs_info->reloc_mutex);
+ goto scrub_continue;
+ }
+
+ /*
+ * 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) {
+ mutex_unlock(&fs_info->reloc_mutex);
+ goto scrub_continue;
+ }
+
+ ret = btrfs_run_delayed_refs(trans, (unsigned long)-1);
+ if (ret) {
+ mutex_unlock(&fs_info->reloc_mutex);
+ goto scrub_continue;
+ }
+
+ /*
+ * 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);
+
+ /* btrfs_commit_tree_roots is responsible for getting the
+ * various roots consistent with each other. Every pointer
+ * in the tree of tree roots has to point to the most up to date
+ * root for every subvolume and other tree. So, we have to keep
+ * the tree logging code from jumping in and changing any
+ * of the trees.
+ *
+ * At this point in the commit, there can't be any tree-log
+ * writers, but a little lower down we drop the trans mutex
+ * and let new people in. By holding the tree_log_mutex
+ * from now until after the super is written, we avoid races
+ * with the tree-log code.
+ */
+ mutex_lock(&fs_info->tree_log_mutex);
+
+ ret = commit_fs_roots(trans);
+ if (ret) {
+ mutex_unlock(&fs_info->tree_log_mutex);
+ mutex_unlock(&fs_info->reloc_mutex);
+ goto scrub_continue;
+ }
+
+ /*
+ * 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);
+
+ /*
+ * commit_fs_roots() can call btrfs_save_ino_cache(), which generates
+ * new delayed refs. Must handle them or qgroup can be wrong.
+ */
+ ret = btrfs_run_delayed_refs(trans, (unsigned long)-1);
+ if (ret) {
+ mutex_unlock(&fs_info->tree_log_mutex);
+ mutex_unlock(&fs_info->reloc_mutex);
+ goto scrub_continue;
+ }
+
+ /*
+ * 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) {
+ mutex_unlock(&fs_info->tree_log_mutex);
+ mutex_unlock(&fs_info->reloc_mutex);
+ goto scrub_continue;
+ }
+
+ ret = commit_cowonly_roots(trans);
+ if (ret) {
+ mutex_unlock(&fs_info->tree_log_mutex);
+ mutex_unlock(&fs_info->reloc_mutex);
+ goto scrub_continue;
+ }
+
+ /*
+ * 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;
+ mutex_unlock(&fs_info->tree_log_mutex);
+ mutex_unlock(&fs_info->reloc_mutex);
+ goto scrub_continue;
+ }
+
+ btrfs_prepare_extent_commit(fs_info);
+
+ 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);
+
+ 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);
+
+ 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;
+ }
+
+ 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;
+
+ 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(trans->root);
+
+ btrfs_scrub_continue(fs_info);
+
+ if (current->journal_info == trans)
+ current->journal_info = NULL;
+
+ kmem_cache_free(btrfs_trans_handle_cachep, trans);
+
+ return ret;
+
+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_root *root)
+{
+ int ret;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+
+ 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, NULL, 0, 0);
+ else
+ ret = btrfs_drop_snapshot(root, NULL, 1, 0);
+
+ 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_SET_INODE_MAP_CACHE;
+ if (prev & bit)
+ btrfs_set_opt(fs_info->mount_opt, INODE_MAP_CACHE);
+ prev &= ~bit;
+
+ bit = 1 << BTRFS_PENDING_CLEAR_INODE_MAP_CACHE;
+ if (prev & bit)
+ btrfs_clear_opt(fs_info->mount_opt, INODE_MAP_CACHE);
+ prev &= ~bit;
+
+ 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);
+}