mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-16 08:44:21 +08:00
7b7a8665ed
Add support to the core direct-io code to defer AIO completions to user context using a workqueue. This replaces opencoded and less efficient code in XFS and ext4 (we save a memory allocation for each direct IO) and will be needed to properly support O_(D)SYNC for AIO. The communication between the filesystem and the direct I/O code requires a new buffer head flag, which is a bit ugly but not avoidable until the direct I/O code stops abusing the buffer_head structure for communicating with the filesystems. Currently this creates a per-superblock unbound workqueue for these completions, which is taken from an earlier patch by Jan Kara. I'm not really convinced about this use and would prefer a "normal" global workqueue with a high concurrency limit, but this needs further discussion. JK: Fixed ext4 part, dynamic allocation of the workqueue. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
64 lines
2.3 KiB
C
64 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 mempool_t *xfs_ioend_pool;
|
|
|
|
/*
|
|
* Types of I/O for bmap clustering and I/O completion tracking.
|
|
*/
|
|
enum {
|
|
XFS_IO_DIRECT = 0, /* special case for direct I/O ioends */
|
|
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 \
|
|
{ 0, "" }, \
|
|
{ XFS_IO_DELALLOC, "delalloc" }, \
|
|
{ XFS_IO_UNWRITTEN, "unwritten" }, \
|
|
{ XFS_IO_OVERWRITE, "overwrite" }
|
|
|
|
/*
|
|
* xfs_ioend struct manages large extent writes for XFS.
|
|
* It can manage several multi-page bio's at once.
|
|
*/
|
|
typedef struct xfs_ioend {
|
|
struct xfs_ioend *io_list; /* next ioend in chain */
|
|
unsigned int io_type; /* delalloc / unwritten */
|
|
int io_error; /* I/O error code */
|
|
atomic_t io_remaining; /* hold count */
|
|
unsigned int io_isdirect : 1;/* direct I/O */
|
|
struct inode *io_inode; /* file being written to */
|
|
struct buffer_head *io_buffer_head;/* buffer linked list head */
|
|
struct buffer_head *io_buffer_tail;/* buffer linked list tail */
|
|
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 */
|
|
} xfs_ioend_t;
|
|
|
|
extern const struct address_space_operations xfs_address_space_operations;
|
|
extern int xfs_get_blocks(struct inode *, sector_t, struct buffer_head *, int);
|
|
|
|
extern void xfs_count_page_state(struct page *, int *, int *);
|
|
|
|
#endif /* __XFS_AOPS_H__ */
|