kernel-ark/fs/btrfs/transaction.h
Josef Bacik 569e0f358c Btrfs: place ordered operations on a per transaction list
Miao made the ordered operations stuff run async, which introduced a
deadlock where we could get somebody (sync) racing in and committing the
transaction while a commit was already happening.  The new committer would
try and flush ordered operations which would hang waiting for the commit to
finish because it is done asynchronously and no longer inherits the callers
trans handle.  To fix this we need to make the ordered operations list a per
transaction list.  We can get new inodes added to the ordered operation list
by truncating them and then having another process writing to them, so this
makes it so that anybody trying to add an ordered operation _must_ start a
transaction in order to add itself to the list, which will keep new inodes
from getting added to the ordered operations list after we start committing.
This should fix the deadlock and also keeps us from doing a lot more work
than we need to during commit.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-02-20 12:59:57 -05:00

147 lines
4.9 KiB
C

/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#ifndef __BTRFS_TRANSACTION__
#define __BTRFS_TRANSACTION__
#include "btrfs_inode.h"
#include "delayed-ref.h"
#include "ctree.h"
struct btrfs_transaction {
u64 transid;
/*
* total writers in this transaction, it must be zero before the
* transaction can end
*/
atomic_t num_writers;
atomic_t use_count;
unsigned long num_joined;
spinlock_t commit_lock;
int in_commit;
int commit_done;
int blocked;
struct list_head list;
struct extent_io_tree dirty_pages;
unsigned long start_time;
wait_queue_head_t writer_wait;
wait_queue_head_t commit_wait;
struct list_head pending_snapshots;
struct list_head ordered_operations;
struct btrfs_delayed_ref_root delayed_refs;
int aborted;
};
enum btrfs_trans_type {
TRANS_START,
TRANS_JOIN,
TRANS_USERSPACE,
TRANS_JOIN_NOLOCK,
TRANS_ATTACH,
};
struct btrfs_trans_handle {
u64 transid;
u64 bytes_reserved;
u64 qgroup_reserved;
unsigned long use_count;
unsigned long blocks_reserved;
unsigned long blocks_used;
unsigned long delayed_ref_updates;
struct btrfs_transaction *transaction;
struct btrfs_block_rsv *block_rsv;
struct btrfs_block_rsv *orig_rsv;
short aborted;
short adding_csums;
bool allocating_chunk;
enum btrfs_trans_type type;
/*
* this root is only needed to validate that the root passed to
* start_transaction is the same as the one passed to end_transaction.
* Subvolume quota depends on this
*/
struct btrfs_root *root;
struct seq_list delayed_ref_elem;
struct list_head qgroup_ref_list;
struct list_head new_bgs;
};
struct btrfs_pending_snapshot {
struct dentry *dentry;
struct btrfs_root *root;
struct btrfs_root *snap;
struct btrfs_qgroup_inherit *inherit;
/* block reservation for the operation */
struct btrfs_block_rsv block_rsv;
/* extra metadata reseration for relocation */
int error;
bool readonly;
struct list_head list;
};
static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
struct inode *inode)
{
BTRFS_I(inode)->last_trans = trans->transaction->transid;
BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
}
int btrfs_end_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
int num_items);
struct btrfs_trans_handle *btrfs_start_transaction_lflush(
struct btrfs_root *root, int num_items);
struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root);
struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root);
int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid);
int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_add_dead_root(struct btrfs_root *root);
int btrfs_defrag_root(struct btrfs_root *root);
int btrfs_clean_old_snapshots(struct btrfs_root *root);
int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
int wait_for_unblock);
int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_end_transaction_dmeta(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
void btrfs_throttle(struct btrfs_root *root);
int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
struct extent_io_tree *dirty_pages, int mark);
int btrfs_write_marked_extents(struct btrfs_root *root,
struct extent_io_tree *dirty_pages, int mark);
int btrfs_wait_marked_extents(struct btrfs_root *root,
struct extent_io_tree *dirty_pages, int mark);
int btrfs_transaction_blocked(struct btrfs_fs_info *info);
int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
void put_transaction(struct btrfs_transaction *transaction);
#endif