backing-dev.h revision a27d2baa0c1a2ec70f47ea9199b1dd6762c8a349 
1/****************************************************************************
2 ****************************************************************************
3 ***
4 ***   This header was automatically generated from a Linux kernel header
5 ***   of the same name, to make information necessary for userspace to
6 ***   call into the kernel available to libc.  It contains only constants,
7 ***   structures, and macros generated from the original header, and thus,
8 ***   contains no copyrightable information.
9 ***
10 ****************************************************************************
11 ****************************************************************************/
12#ifndef _LINUX_BACKING_DEV_H
13#define _LINUX_BACKING_DEV_H
14
15#include <asm/atomic.h>
16
17enum bdi_state {
18 BDI_pdflush,
19 BDI_write_congested,
20 BDI_read_congested,
21 BDI_unused,
22};
23
24typedef int (congested_fn)(void *, int);
25
26struct backing_dev_info {
27 unsigned long ra_pages;
28 unsigned long state;
29 unsigned int capabilities;
30 congested_fn *congested_fn;
31 void *congested_data;
32 void (*unplug_io_fn)(struct backing_dev_info *, struct page *);
33 void *unplug_io_data;
34};
35
36#define BDI_CAP_NO_ACCT_DIRTY 0x00000001
37#define BDI_CAP_NO_WRITEBACK 0x00000002
38#define BDI_CAP_MAP_COPY 0x00000004
39#define BDI_CAP_MAP_DIRECT 0x00000008
40#define BDI_CAP_READ_MAP 0x00000010
41#define BDI_CAP_WRITE_MAP 0x00000020
42#define BDI_CAP_EXEC_MAP 0x00000040
43#define BDI_CAP_VMFLAGS   (BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP)
44
45#if defined(VM_MAYREAD) && BDI_CAP_READ_MAP != (VM_MAYREAD || BDI_CAP_WRITE_MAP != (VM_MAYWRITE || BDI_CAP_EXEC_MAP != VM_MAYEXEC))
46#error please change backing_dev_info::capabilities flags
47#endif
48
49#define bdi_cap_writeback_dirty(bdi)   (!((bdi)->capabilities & BDI_CAP_NO_WRITEBACK))
50#define bdi_cap_account_dirty(bdi)   (!((bdi)->capabilities & BDI_CAP_NO_ACCT_DIRTY))
51#define mapping_cap_writeback_dirty(mapping)   bdi_cap_writeback_dirty((mapping)->backing_dev_info)
52#define mapping_cap_account_dirty(mapping)   bdi_cap_account_dirty((mapping)->backing_dev_info)
53#endif
54