linux/fs/xfs/xfs_aops.h
Christoph Hellwig 0e51a8e191 xfs: optimize bio handling in the buffer writeback path
This patch implements two closely related changes:  First it embeds
a bio the ioend structure so that we don't have to allocate one
separately.  Second it uses the block layer bio chaining mechanism
to chain additional bios off this first one if needed instead of
manually accounting for multiple bio completions in the ioend
structure.  Together this removes a memory allocation per ioend and
greatly simplifies the ioend setup and I/O completion path.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-04-06 08:34:30 +10:00

67 lines
2.3 KiB
C

/*
* Copyright (c) 2005-2006 Silicon Graphics, Inc.
* 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 as
* published by the Free Software Foundation.
*
* 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_AOPS_H__
#define __XFS_AOPS_H__
extern struct bio_set *xfs_ioend_bioset;
/*
* Types of I/O for bmap clustering and I/O completion tracking.
*/
enum {
XFS_IO_INVALID, /* initial state */
XFS_IO_DELALLOC, /* covers delalloc region */
XFS_IO_UNWRITTEN, /* covers allocated but uninitialized data */
XFS_IO_OVERWRITE, /* covers already allocated extent */
};
#define XFS_IO_TYPES \
{ XFS_IO_INVALID, "invalid" }, \
{ XFS_IO_DELALLOC, "delalloc" }, \
{ XFS_IO_UNWRITTEN, "unwritten" }, \
{ XFS_IO_OVERWRITE, "overwrite" }
/*
* Structure for buffered I/O completions.
*/
struct xfs_ioend {
struct list_head io_list; /* next ioend in chain */
unsigned int io_type; /* delalloc / unwritten */
struct inode *io_inode; /* file being written to */
size_t io_size; /* size of the extent */
xfs_off_t io_offset; /* offset in the file */
struct work_struct io_work; /* xfsdatad work queue */
struct xfs_trans *io_append_trans;/* xact. for size update */
struct bio *io_bio; /* bio being built */
struct bio io_inline_bio; /* MUST BE LAST! */
};
extern const struct address_space_operations xfs_address_space_operations;
int xfs_get_blocks(struct inode *inode, sector_t offset,
struct buffer_head *map_bh, int create);
int xfs_get_blocks_direct(struct inode *inode, sector_t offset,
struct buffer_head *map_bh, int create);
int xfs_get_blocks_dax_fault(struct inode *inode, sector_t offset,
struct buffer_head *map_bh, int create);
extern void xfs_count_page_state(struct page *, int *, int *);
extern struct block_device *xfs_find_bdev_for_inode(struct inode *);
#endif /* __XFS_AOPS_H__ */