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linux/fs/btrfs/transaction.h
Li Zefan b83cc9693f Btrfs: Add readonly snapshots support
Usage:

Set BTRFS_SUBVOL_RDONLY of btrfs_ioctl_vol_arg_v2->flags, and call
ioctl(BTRFS_I0CTL_SNAP_CREATE_V2).

Implementation:

- Set readonly bit of btrfs_root_item->flags.
- Add readonly checks in btrfs_permission (inode_permission),
btrfs_setattr, btrfs_set/remove_xattr and some ioctls.

Changelog for v3:

- Eliminate btrfs_root->readonly, but check btrfs_root->root_item.flags.
- Rename BTRFS_ROOT_SNAP_RDONLY to BTRFS_ROOT_SUBVOL_RDONLY.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-23 08:49:17 +08:00

132 lines
4.5 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"
struct btrfs_transaction {
u64 transid;
/*
* total writers in this transaction, it must be zero before the
* transaction can end
*/
unsigned long num_writers;
unsigned long num_joined;
int in_commit;
int use_count;
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 btrfs_delayed_ref_root delayed_refs;
};
struct btrfs_trans_handle {
u64 transid;
u64 block_group;
u64 bytes_reserved;
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_pending_snapshot {
struct dentry *dentry;
struct btrfs_root *root;
struct btrfs_root *snap;
/* 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_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;
BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
}
int btrfs_end_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_end_transaction_nolock(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_join_transaction(struct btrfs_root *root,
int num_blocks);
struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root,
int num_blocks);
struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r,
int num_blocks);
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_commit_tree_roots(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_add_dead_root(struct btrfs_root *root);
int btrfs_drop_dead_root(struct btrfs_root *root);
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_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_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);
#endif