354aa0fb6d
With the following debug patch:
static int btrfs_freeze(struct super_block *sb)
{
+ struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+ struct btrfs_transaction *trans;
+
+ spin_lock(&fs_info->trans_lock);
+ trans = fs_info->running_transaction;
+ if (trans) {
+ printk("Transid %llu, use_count %d, num_writer %d\n",
+ trans->transid, atomic_read(&trans->use_count),
+ atomic_read(&trans->num_writers));
+ }
+ spin_unlock(&fs_info->trans_lock);
return 0;
}
I found there was a orphan transaction after the freeze operation was done.
It is because the transaction may not be committed when the transaction handle
end even though it is the last handle of the current transaction. This design
avoid committing the transaction frequently, but also introduce the above
problem.
So I add btrfs_attach_transaction() which can catch the current transaction
and commit it. If there is no transaction, it will return ENOENT, and do not
anything.
This function also can be used to instead of btrfs_join_transaction_freeze()
because it don't increase the writer counter and don't start a new transaction,
so it also can fix the deadlock between sync and freeze.
Besides that, it is used to instead of btrfs_join_transaction() in
transaction_kthread(), because if there is no transaction, the transaction
kthread needn't anything.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
145 lines
4.8 KiB
C
145 lines
4.8 KiB
C
/*
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* Copyright (C) 2007 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#ifndef __BTRFS_TRANSACTION__
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#define __BTRFS_TRANSACTION__
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#include "btrfs_inode.h"
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#include "delayed-ref.h"
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#include "ctree.h"
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struct btrfs_transaction {
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u64 transid;
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/*
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* total writers in this transaction, it must be zero before the
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* transaction can end
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*/
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atomic_t num_writers;
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atomic_t use_count;
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unsigned long num_joined;
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spinlock_t commit_lock;
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int in_commit;
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int commit_done;
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int blocked;
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struct list_head list;
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struct extent_io_tree dirty_pages;
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unsigned long start_time;
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wait_queue_head_t writer_wait;
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wait_queue_head_t commit_wait;
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struct list_head pending_snapshots;
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struct btrfs_delayed_ref_root delayed_refs;
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int aborted;
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};
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enum btrfs_trans_type {
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TRANS_START,
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TRANS_JOIN,
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TRANS_USERSPACE,
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TRANS_JOIN_NOLOCK,
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TRANS_ATTACH,
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};
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struct btrfs_trans_handle {
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u64 transid;
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u64 bytes_reserved;
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u64 qgroup_reserved;
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unsigned long use_count;
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unsigned long blocks_reserved;
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unsigned long blocks_used;
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unsigned long delayed_ref_updates;
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struct btrfs_transaction *transaction;
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struct btrfs_block_rsv *block_rsv;
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struct btrfs_block_rsv *orig_rsv;
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short aborted;
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short adding_csums;
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enum btrfs_trans_type type;
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/*
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* this root is only needed to validate that the root passed to
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* start_transaction is the same as the one passed to end_transaction.
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* Subvolume quota depends on this
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*/
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struct btrfs_root *root;
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struct seq_list delayed_ref_elem;
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struct list_head qgroup_ref_list;
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struct list_head new_bgs;
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};
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struct btrfs_pending_snapshot {
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struct dentry *dentry;
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struct btrfs_root *root;
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struct btrfs_root *snap;
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struct btrfs_qgroup_inherit *inherit;
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/* block reservation for the operation */
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struct btrfs_block_rsv block_rsv;
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/* extra metadata reseration for relocation */
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int error;
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bool readonly;
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struct list_head list;
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};
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static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
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struct inode *inode)
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{
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BTRFS_I(inode)->last_trans = trans->transaction->transid;
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BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
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BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
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}
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int btrfs_end_transaction(struct btrfs_trans_handle *trans,
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struct btrfs_root *root);
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struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
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int num_items);
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struct btrfs_trans_handle *btrfs_start_transaction_noflush(
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struct btrfs_root *root, int num_items);
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struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
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struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root);
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struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
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struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root);
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int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid);
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int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
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struct btrfs_root *root);
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int btrfs_add_dead_root(struct btrfs_root *root);
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int btrfs_defrag_root(struct btrfs_root *root, int cacheonly);
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int btrfs_clean_old_snapshots(struct btrfs_root *root);
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int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
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struct btrfs_root *root);
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int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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int wait_for_unblock);
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int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
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struct btrfs_root *root);
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int btrfs_end_transaction_dmeta(struct btrfs_trans_handle *trans,
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struct btrfs_root *root);
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int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
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struct btrfs_root *root);
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void btrfs_throttle(struct btrfs_root *root);
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int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
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struct btrfs_root *root);
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int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
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struct extent_io_tree *dirty_pages, int mark);
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int btrfs_write_marked_extents(struct btrfs_root *root,
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struct extent_io_tree *dirty_pages, int mark);
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int btrfs_wait_marked_extents(struct btrfs_root *root,
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struct extent_io_tree *dirty_pages, int mark);
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int btrfs_transaction_blocked(struct btrfs_fs_info *info);
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int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
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void put_transaction(struct btrfs_transaction *transaction);
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#endif
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