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[/] [test_project/] [trunk/] [linux_sd_driver/] [mm/] [fadvise.c] - Blame information for rev 82

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/*
 * mm/fadvise.c
 *
 * Copyright (C) 2002, Linus Torvalds
 *
 * 11Jan2003    akpm@digeo.com
 *              Initial version.
 */
 
#include <linux/kernel.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/backing-dev.h>
#include <linux/pagevec.h>
#include <linux/fadvise.h>
#include <linux/writeback.h>
#include <linux/syscalls.h>
 
#include <asm/unistd.h>
 
/*
 * POSIX_FADV_WILLNEED could set PG_Referenced, and POSIX_FADV_NOREUSE could
 * deactivate the pages and clear PG_Referenced.
 */
asmlinkage long sys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
{
        struct file *file = fget(fd);
        struct address_space *mapping;
        struct backing_dev_info *bdi;
        loff_t endbyte;                 /* inclusive */
        pgoff_t start_index;
        pgoff_t end_index;
        unsigned long nrpages;
        int ret = 0;
 
        if (!file)
                return -EBADF;
 
        if (S_ISFIFO(file->f_path.dentry->d_inode->i_mode)) {
                ret = -ESPIPE;
                goto out;
        }
 
        mapping = file->f_mapping;
        if (!mapping || len < 0) {
                ret = -EINVAL;
                goto out;
        }
 
        if (mapping->a_ops->get_xip_page)
                /* no bad return value, but ignore advice */
                goto out;
 
        /* Careful about overflows. Len == 0 means "as much as possible" */
        endbyte = offset + len;
        if (!len || endbyte < len)
                endbyte = -1;
        else
                endbyte--;              /* inclusive */
 
        bdi = mapping->backing_dev_info;
 
        switch (advice) {
        case POSIX_FADV_NORMAL:
                file->f_ra.ra_pages = bdi->ra_pages;
                break;
        case POSIX_FADV_RANDOM:
                file->f_ra.ra_pages = 0;
                break;
        case POSIX_FADV_SEQUENTIAL:
                file->f_ra.ra_pages = bdi->ra_pages * 2;
                break;
        case POSIX_FADV_WILLNEED:
                if (!mapping->a_ops->readpage) {
                        ret = -EINVAL;
                        break;
                }
 
                /* First and last PARTIAL page! */
                start_index = offset >> PAGE_CACHE_SHIFT;
                end_index = endbyte >> PAGE_CACHE_SHIFT;
 
                /* Careful about overflow on the "+1" */
                nrpages = end_index - start_index + 1;
                if (!nrpages)
                        nrpages = ~0UL;
 
                ret = force_page_cache_readahead(mapping, file,
                                start_index,
                                max_sane_readahead(nrpages));
                if (ret > 0)
                        ret = 0;
                break;
        case POSIX_FADV_NOREUSE:
                break;
        case POSIX_FADV_DONTNEED:
                if (!bdi_write_congested(mapping->backing_dev_info))
                        filemap_flush(mapping);
 
                /* First and last FULL page! */
                start_index = (offset+(PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;
                end_index = (endbyte >> PAGE_CACHE_SHIFT);
 
                if (end_index >= start_index)
                        invalidate_mapping_pages(mapping, start_index,
                                                end_index);
                break;
        default:
                ret = -EINVAL;
        }
out:
        fput(file);
        return ret;
}
 
#ifdef __ARCH_WANT_SYS_FADVISE64
 
asmlinkage long sys_fadvise64(int fd, loff_t offset, size_t len, int advice)
{
        return sys_fadvise64_64(fd, offset, len, advice);
}
 
#endif

Line No.	Rev	Author	Line
1	62	marcus.erl	`/*`
2			`* mm/fadvise.c`
3			`*`
4			`* Copyright (C) 2002, Linus Torvalds`
5			`*`
6			`* 11Jan2003 akpm@digeo.com`
7			`* Initial version.`
8			`*/`
9
10			`#include <linux/kernel.h>`
11			`#include <linux/file.h>`
12			`#include <linux/fs.h>`
13			`#include <linux/mm.h>`
14			`#include <linux/pagemap.h>`
15			`#include <linux/backing-dev.h>`
16			`#include <linux/pagevec.h>`
17			`#include <linux/fadvise.h>`
18			`#include <linux/writeback.h>`
19			`#include <linux/syscalls.h>`
20
21			`#include <asm/unistd.h>`
22
23			`/*`
24			`* POSIX_FADV_WILLNEED could set PG_Referenced, and POSIX_FADV_NOREUSE could`
25			`* deactivate the pages and clear PG_Referenced.`
26			`*/`
27			`asmlinkage long sys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)`
28			`{`
29			`struct file *file = fget(fd);`
30			`struct address_space *mapping;`
31			`struct backing_dev_info *bdi;`
32			`loff_t endbyte; /* inclusive */`
33			`pgoff_t start_index;`
34			`pgoff_t end_index;`
35			`unsigned long nrpages;`
36			`int ret = 0;`
37
38			`if (!file)`
39			`return -EBADF;`
40
41			`if (S_ISFIFO(file->f_path.dentry->d_inode->i_mode)) {`
42			`ret = -ESPIPE;`
43			`goto out;`
44			`}`
45
46			`mapping = file->f_mapping;`
47			`if (!mapping \|\| len < 0) {`
48			`ret = -EINVAL;`
49			`goto out;`
50			`}`
51
52			`if (mapping->a_ops->get_xip_page)`
53			`/* no bad return value, but ignore advice */`
54			`goto out;`
55
56			`/* Careful about overflows. Len == 0 means "as much as possible" */`
57			`endbyte = offset + len;`
58			`if (!len \|\| endbyte < len)`
59			`endbyte = -1;`
60			`else`
61			`endbyte--; /* inclusive */`
62
63			`bdi = mapping->backing_dev_info;`
64
65			`switch (advice) {`
66			`case POSIX_FADV_NORMAL:`
67			`file->f_ra.ra_pages = bdi->ra_pages;`
68			`break;`
69			`case POSIX_FADV_RANDOM:`
70			`file->f_ra.ra_pages = 0;`
71			`break;`
72			`case POSIX_FADV_SEQUENTIAL:`
73			`file->f_ra.ra_pages = bdi->ra_pages * 2;`
74			`break;`
75			`case POSIX_FADV_WILLNEED:`
76			`if (!mapping->a_ops->readpage) {`
77			`ret = -EINVAL;`
78			`break;`
79			`}`
80
81			`/* First and last PARTIAL page! */`
82			`start_index = offset >> PAGE_CACHE_SHIFT;`
83			`end_index = endbyte >> PAGE_CACHE_SHIFT;`
84
85			`/* Careful about overflow on the "+1" */`
86			`nrpages = end_index - start_index + 1;`
87			`if (!nrpages)`
88			`nrpages = ~0UL;`
89
90			`ret = force_page_cache_readahead(mapping, file,`
91			`start_index,`
92			`max_sane_readahead(nrpages));`
93			`if (ret > 0)`
94			`ret = 0;`
95			`break;`
96			`case POSIX_FADV_NOREUSE:`
97			`break;`
98			`case POSIX_FADV_DONTNEED:`
99			`if (!bdi_write_congested(mapping->backing_dev_info))`
100			`filemap_flush(mapping);`
101
102			`/* First and last FULL page! */`
103			`start_index = (offset+(PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;`
104			`end_index = (endbyte >> PAGE_CACHE_SHIFT);`
105
106			`if (end_index >= start_index)`
107			`invalidate_mapping_pages(mapping, start_index,`
108			`end_index);`
109			`break;`
110			`default:`
111			`ret = -EINVAL;`
112			`}`
113			`out:`
114			`fput(file);`
115			`return ret;`
116			`}`
117
118			`#ifdef __ARCH_WANT_SYS_FADVISE64`
119
120			`asmlinkage long sys_fadvise64(int fd, loff_t offset, size_t len, int advice)`
121			`{`
122			`return sys_fadvise64_64(fd, offset, len, advice);`
123			`}`
124
125			`#endif`

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[/] [test_project/] [trunk/] [linux_sd_driver/] [mm/] [fadvise.c] - Blame information for rev 82