linux/fs/btrfs/transaction.h
Jeff Mahoney 64c12921e1 btrfs: account for non-CoW'd blocks in btrfs_abort_transaction
The test for !trans->blocks_used in btrfs_abort_transaction is
insufficient to determine whether it's safe to drop the transaction
handle on the floor.  btrfs_cow_block, informed by should_cow_block,
can return blocks that have already been CoW'd in the current
transaction.  trans->blocks_used is only incremented for new block
allocations. If an operation overlaps the blocks in the current
transaction entirely and must abort the transaction, we'll happily
let it clean up the trans handle even though it may have modified
the blocks and will commit an incomplete operation.

In the long-term, I'd like to do closer tracking of when the fs
is actually modified so we can still recover as gracefully as possible,
but that approach will need some discussion.  In the short term,
since this is the only code using trans->blocks_used, let's just
switch it to a bool indicating whether any blocks were used and set
it when should_cow_block returns false.

Cc: stable@vger.kernel.org # 3.4+
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-17 18:32:40 +02:00

231 lines
7.4 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"
enum btrfs_trans_state {
TRANS_STATE_RUNNING = 0,
TRANS_STATE_BLOCKED = 1,
TRANS_STATE_COMMIT_START = 2,
TRANS_STATE_COMMIT_DOING = 3,
TRANS_STATE_UNBLOCKED = 4,
TRANS_STATE_COMPLETED = 5,
TRANS_STATE_MAX = 6,
};
#define BTRFS_TRANS_HAVE_FREE_BGS 0
#define BTRFS_TRANS_DIRTY_BG_RUN 1
#define BTRFS_TRANS_CACHE_ENOSPC 2
struct btrfs_transaction {
u64 transid;
/*
* total external writers(USERSPACE/START/ATTACH) in this
* transaction, it must be zero before the transaction is
* being committed
*/
atomic_t num_extwriters;
/*
* total writers in this transaction, it must be zero before the
* transaction can end
*/
atomic_t num_writers;
atomic_t use_count;
atomic_t pending_ordered;
unsigned long flags;
/* Be protected by fs_info->trans_lock when we want to change it. */
enum btrfs_trans_state state;
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;
wait_queue_head_t pending_wait;
struct list_head pending_snapshots;
struct list_head pending_chunks;
struct list_head switch_commits;
struct list_head dirty_bgs;
struct list_head io_bgs;
struct list_head dropped_roots;
u64 num_dirty_bgs;
/*
* we need to make sure block group deletion doesn't race with
* free space cache writeout. This mutex keeps them from stomping
* on each other
*/
struct mutex cache_write_mutex;
spinlock_t dirty_bgs_lock;
/* Protected by spin lock fs_info->unused_bgs_lock. */
struct list_head deleted_bgs;
spinlock_t dropped_roots_lock;
struct btrfs_delayed_ref_root delayed_refs;
int aborted;
};
#define __TRANS_FREEZABLE (1U << 0)
#define __TRANS_USERSPACE (1U << 8)
#define __TRANS_START (1U << 9)
#define __TRANS_ATTACH (1U << 10)
#define __TRANS_JOIN (1U << 11)
#define __TRANS_JOIN_NOLOCK (1U << 12)
#define __TRANS_DUMMY (1U << 13)
#define TRANS_USERSPACE (__TRANS_USERSPACE | __TRANS_FREEZABLE)
#define TRANS_START (__TRANS_START | __TRANS_FREEZABLE)
#define TRANS_ATTACH (__TRANS_ATTACH)
#define TRANS_JOIN (__TRANS_JOIN | __TRANS_FREEZABLE)
#define TRANS_JOIN_NOLOCK (__TRANS_JOIN_NOLOCK)
#define TRANS_EXTWRITERS (__TRANS_USERSPACE | __TRANS_START | \
__TRANS_ATTACH)
#define BTRFS_SEND_TRANS_STUB ((void *)1)
struct btrfs_trans_handle {
u64 transid;
u64 bytes_reserved;
u64 chunk_bytes_reserved;
unsigned long use_count;
unsigned long blocks_reserved;
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;
bool can_flush_pending_bgs;
bool reloc_reserved;
bool sync;
bool dirty;
unsigned int 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 inode *dir;
struct btrfs_root *root;
struct btrfs_root_item *root_item;
struct btrfs_root *snap;
struct btrfs_qgroup_inherit *inherit;
struct btrfs_path *path;
/* block reservation for the operation */
struct btrfs_block_rsv block_rsv;
u64 qgroup_reserved;
/* extra metadata reservation 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)
{
spin_lock(&BTRFS_I(inode)->lock);
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;
spin_unlock(&BTRFS_I(inode)->lock);
}
/*
* Make qgroup codes to skip given qgroupid, means the old/new_roots for
* qgroup won't contain the qgroupid in it.
*/
static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
u64 qgroupid)
{
struct btrfs_delayed_ref_root *delayed_refs;
delayed_refs = &trans->transaction->delayed_refs;
WARN_ON(delayed_refs->qgroup_to_skip);
delayed_refs->qgroup_to_skip = qgroupid;
}
static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
{
struct btrfs_delayed_ref_root *delayed_refs;
delayed_refs = &trans->transaction->delayed_refs;
WARN_ON(!delayed_refs->qgroup_to_skip);
delayed_refs->qgroup_to_skip = 0;
}
int btrfs_end_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
unsigned int num_items);
struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
struct btrfs_root *root,
unsigned int num_items,
int min_factor);
struct btrfs_trans_handle *btrfs_start_transaction_lflush(
struct btrfs_root *root,
unsigned 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_attach_transaction_barrier(
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);
void btrfs_add_dead_root(struct btrfs_root *root);
int btrfs_defrag_root(struct btrfs_root *root);
int btrfs_clean_one_deleted_snapshot(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_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_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 btrfs_put_transaction(struct btrfs_transaction *transaction);
void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
#endif