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linux/fs/btrfs/transaction.h
Chris Mason 89ce8a63d0 Add btrfs_end_transaction_throttle to force writers to wait for pending commits
The existing throttle mechanism was often not sufficient to prevent
new writers from coming in and making a given transaction run forever.
This adds an explicit wait at the end of most operations so they will
allow the current transaction to close.

There is no wait inside file_write, inode updates, or cow filling, all which
have different deadlock possibilities.

This is a temporary measure until better asynchronous commit support is
added.  This code leads to stalls as it waits for data=ordered
writeback, and it really needs to be fixed.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00

107 lines
3.3 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 "ordered-data.h"
struct btrfs_transaction {
u64 transid;
unsigned long num_writers;
unsigned long num_joined;
int in_commit;
int use_count;
int commit_done;
struct list_head list;
struct extent_io_tree dirty_pages;
unsigned long start_time;
struct btrfs_ordered_inode_tree ordered_inode_tree;
wait_queue_head_t writer_wait;
wait_queue_head_t commit_wait;
struct list_head pending_snapshots;
};
struct btrfs_trans_handle {
u64 transid;
unsigned long blocks_reserved;
unsigned long blocks_used;
struct btrfs_transaction *transaction;
struct btrfs_block_group_cache *block_group;
u64 alloc_exclude_start;
u64 alloc_exclude_nr;
};
struct btrfs_pending_snapshot {
struct btrfs_root *root;
char *name;
struct list_head list;
};
static inline void btrfs_set_trans_block_group(struct btrfs_trans_handle *trans,
struct inode *inode)
{
trans->block_group = BTRFS_I(inode)->block_group;
}
static inline void btrfs_update_inode_block_group(struct
btrfs_trans_handle *trans,
struct inode *inode)
{
BTRFS_I(inode)->block_group = trans->block_group;
}
static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
struct inode *inode)
{
BTRFS_I(inode)->last_trans = trans->transaction->transid;
}
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_blocks);
int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
void btrfs_transaction_cleaner(void *p);
#else
void btrfs_transaction_cleaner(struct work_struct *work);
#endif
void btrfs_transaction_flush_work(struct btrfs_root *root);
void btrfs_transaction_queue_work(struct btrfs_root *root, int delay);
void btrfs_init_transaction_sys(void);
void btrfs_exit_transaction_sys(void);
int btrfs_add_dead_root(struct btrfs_root *root, struct btrfs_root *latest,
struct list_head *dead_list);
int btrfs_defrag_dirty_roots(struct btrfs_fs_info *info);
int btrfs_defrag_root(struct btrfs_root *root, int cacheonly);
int btrfs_clean_old_snapshots(struct btrfs_root *root);
int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_write_ordered_inodes(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
#endif