Files
linux_media/fs/xfs/xfs_reflink.h
Darrick J. Wong 2a06705cd5 xfs: create delalloc extents in CoW fork
Wire up iomap_begin to detect shared extents and create delayed allocation
extents in the CoW fork:

 1) Check if we already have an extent in the COW fork for the area.
    If so nothing to do, we can move along.
 2) Look up block number for the current extent, and if there is none
    it's not shared move along.
 3) Unshare the current extent as far as we are going to write into it.
    For this we avoid an additional COW fork lookup and use the
    information we set aside in step 1) above.
 4) Goto 1) unless we've covered the whole range.

Last but not least, this updates the xfs_reflink_reserve_cow_range calling
convention to pass a byte offset and length, as that is what both callers
expect anyway.  This patch has been refactored considerably as part of the
iomap transition.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-10-04 18:06:40 -07:00

33 lines
1.3 KiB
C

/*
* Copyright (C) 2016 Oracle. All Rights Reserved.
*
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it would 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 the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#ifndef __XFS_REFLINK_H
#define __XFS_REFLINK_H 1
extern int xfs_reflink_find_shared(struct xfs_mount *mp, xfs_agnumber_t agno,
xfs_agblock_t agbno, xfs_extlen_t aglen, xfs_agblock_t *fbno,
xfs_extlen_t *flen, bool find_maximal);
extern int xfs_reflink_trim_around_shared(struct xfs_inode *ip,
struct xfs_bmbt_irec *irec, bool *shared, bool *trimmed);
extern int xfs_reflink_reserve_cow_range(struct xfs_inode *ip,
xfs_off_t offset, xfs_off_t count);
#endif /* __XFS_REFLINK_H */