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[/] [or1k/] [trunk/] [uclinux/] [uClinux-2.0.x/] [fs/] [fat/] [mmap.c] - Blame information for rev 1765

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/*
 *      linux/fs/fat/mmap.c
 *
 *      Written by Jacques Gelinas (jacques@solucorp.qc.ca)
 *      Inspired by fs/nfs/mmap.c (Jon Tombs 15 Aug 1993)
 *
 *      mmap handling for fat-based filesystems
 *
 * uClinux revisions for NO_MM
 * Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>,
 *                     The Silver Hammer Group, Ltd.
 */
 
#define ASC_LINUX_VERSION(V, P, S)      (((V) * 65536) + ((P) * 256) + (S))
#include <linux/version.h>
 
#include <linux/stat.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/shm.h>
#include <linux/errno.h>
#include <linux/mman.h>
#include <linux/string.h>
#include <linux/malloc.h>
#include <linux/msdos_fs.h>
 
#if LINUX_VERSION_CODE >= ASC_LINUX_VERSION(2,1,0)
#include <asm/uaccess.h>
#else
#include <asm/segment.h>
#endif
#include <asm/system.h>
 
#ifndef NO_MM
 
/*
 * Fill in the supplied page for mmap
 */
static unsigned long fat_file_mmap_nopage(
        struct vm_area_struct * area,
        unsigned long address,
        int error_code)
{
        struct inode * inode = area->vm_inode;
        unsigned long page;
        unsigned int clear;
        int pos;
        long gap;       /* distance from eof to pos */
 
        page = __get_free_page(GFP_KERNEL);
        if (!page)
                return page;
        address &= PAGE_MASK;
        pos = address - area->vm_start + area->vm_offset;
 
        clear = 0;
        gap = inode->i_size - pos;
        if (gap <= 0){
                /* mmaping beyond end of file */
                clear = PAGE_SIZE;
        }else{
                int cur_read;
                int need_read;
                struct file filp;
                if (gap < PAGE_SIZE){
                        clear = PAGE_SIZE - gap;
                }
                filp.f_reada = 0;
                filp.f_pos = pos;
                need_read = PAGE_SIZE - clear;
                {
                        unsigned long cur_fs = get_fs();
                        set_fs (KERNEL_DS);
                        cur_read = fat_file_read (inode,&filp,(char*)page
                                ,need_read);
                        set_fs (cur_fs);
                }
                if (cur_read != need_read){
                        printk ("MSDOS: Error while reading an mmap file %d <> %d\n"
                                ,cur_read,need_read);
                }
        }
        if (clear > 0){
                memset ((char*)page+PAGE_SIZE-clear,0,clear);
        }
        return page;
}
 
struct vm_operations_struct fat_file_mmap = {
        NULL,                   /* open */
        NULL,                   /* close */
        NULL,                   /* unmap */
        NULL,                   /* protect */
        NULL,                   /* sync */
        NULL,                   /* advise */
        fat_file_mmap_nopage,   /* nopage */
        NULL,                   /* wppage */
        NULL,                   /* swapout */
        NULL,                   /* swapin */
};
 
/*
 * This is used for a general mmap of an msdos file
 * Returns 0 if ok, or a negative error code if not.
 */
int fat_mmap(struct inode * inode, struct file * file, struct vm_area_struct * vma)
{
        if (vma->vm_flags & VM_SHARED)  /* only PAGE_COW or read-only supported now */
                return -EINVAL;
        if (vma->vm_offset & (inode->i_sb->s_blocksize - 1))
                return -EINVAL;
        if (!inode->i_sb || !S_ISREG(inode->i_mode))
                return -EACCES;
        if (!IS_RDONLY(inode)) {
                inode->i_atime = CURRENT_TIME;
                inode->i_dirt = 1;
        }
 
        vma->vm_inode = inode;
        inode->i_count++;
        vma->vm_ops = &fat_file_mmap;
        return 0;
}
 
#else /* NO_MM */
 
int fat_mmap()
{
        return -ENOSYS;
}
 
#endif /* NO_MM */
 

Line No.	Rev	Author	Line
1	199	simons	`/*`
2			`* linux/fs/fat/mmap.c`
3			`*`
4			`* Written by Jacques Gelinas (jacques@solucorp.qc.ca)`
5			`* Inspired by fs/nfs/mmap.c (Jon Tombs 15 Aug 1993)`
6			`*`
7			`* mmap handling for fat-based filesystems`
8			`*`
9			`* uClinux revisions for NO_MM`
10			`* Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com>,`
11			`* The Silver Hammer Group, Ltd.`
12			`*/`
13
14			`#define ASC_LINUX_VERSION(V, P, S) (((V) * 65536) + ((P) * 256) + (S))`
15			`#include <linux/version.h>`
16
17			`#include <linux/stat.h>`
18			`#include <linux/sched.h>`
19			`#include <linux/kernel.h>`
20			`#include <linux/mm.h>`
21			`#include <linux/shm.h>`
22			`#include <linux/errno.h>`
23			`#include <linux/mman.h>`
24			`#include <linux/string.h>`
25			`#include <linux/malloc.h>`
26			`#include <linux/msdos_fs.h>`
27
28			`#if LINUX_VERSION_CODE >= ASC_LINUX_VERSION(2,1,0)`
29			`#include <asm/uaccess.h>`
30			`#else`
31			`#include <asm/segment.h>`
32			`#endif`
33			`#include <asm/system.h>`
34
35			`#ifndef NO_MM`
36
37			`/*`
38			`* Fill in the supplied page for mmap`
39			`*/`
40			`static unsigned long fat_file_mmap_nopage(`
41			`struct vm_area_struct * area,`
42			`unsigned long address,`
43			`int error_code)`
44			`{`
45			`struct inode * inode = area->vm_inode;`
46			`unsigned long page;`
47			`unsigned int clear;`
48			`int pos;`
49			`long gap; /* distance from eof to pos */`
50
51			`page = __get_free_page(GFP_KERNEL);`
52			`if (!page)`
53			`return page;`
54			`address &= PAGE_MASK;`
55			`pos = address - area->vm_start + area->vm_offset;`
56
57			`clear = 0;`
58			`gap = inode->i_size - pos;`
59			`if (gap <= 0){`
60			`/* mmaping beyond end of file */`
61			`clear = PAGE_SIZE;`
62			`}else{`
63			`int cur_read;`
64			`int need_read;`
65			`struct file filp;`
66			`if (gap < PAGE_SIZE){`
67			`clear = PAGE_SIZE - gap;`
68			`}`
69			`filp.f_reada = 0;`
70			`filp.f_pos = pos;`
71			`need_read = PAGE_SIZE - clear;`
72			`{`
73			`unsigned long cur_fs = get_fs();`
74			`set_fs (KERNEL_DS);`
75			`cur_read = fat_file_read (inode,&filp,(char*)page`
76			`,need_read);`
77			`set_fs (cur_fs);`
78			`}`
79			`if (cur_read != need_read){`
80			`printk ("MSDOS: Error while reading an mmap file %d <> %d\n"`
81			`,cur_read,need_read);`
82			`}`
83			`}`
84			`if (clear > 0){`
85			`memset ((char*)page+PAGE_SIZE-clear,0,clear);`
86			`}`
87			`return page;`
88			`}`
89
90			`struct vm_operations_struct fat_file_mmap = {`
91			`NULL, /* open */`
92			`NULL, /* close */`
93			`NULL, /* unmap */`
94			`NULL, /* protect */`
95			`NULL, /* sync */`
96			`NULL, /* advise */`
97			`fat_file_mmap_nopage, /* nopage */`
98			`NULL, /* wppage */`
99			`NULL, /* swapout */`
100			`NULL, /* swapin */`
101			`};`
102
103			`/*`
104			`* This is used for a general mmap of an msdos file`
105			`* Returns 0 if ok, or a negative error code if not.`
106			`*/`
107			`int fat_mmap(struct inode * inode, struct file * file, struct vm_area_struct * vma)`
108			`{`
109			`if (vma->vm_flags & VM_SHARED) /* only PAGE_COW or read-only supported now */`
110			`return -EINVAL;`
111			`if (vma->vm_offset & (inode->i_sb->s_blocksize - 1))`
112			`return -EINVAL;`
113			`if (!inode->i_sb \|\| !S_ISREG(inode->i_mode))`
114			`return -EACCES;`
115			`if (!IS_RDONLY(inode)) {`
116			`inode->i_atime = CURRENT_TIME;`
117			`inode->i_dirt = 1;`
118			`}`
119
120			`vma->vm_inode = inode;`
121			`inode->i_count++;`
122			`vma->vm_ops = &fat_file_mmap;`
123			`return 0;`
124			`}`
125
126			`#else /* NO_MM */`
127
128			`int fat_mmap()`
129			`{`
130			`return -ENOSYS;`
131			`}`
132
133			`#endif /* NO_MM */`
134

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[/] [or1k/] [trunk/] [uclinux/] [uClinux-2.0.x/] [fs/] [fat/] [mmap.c] - Blame information for rev 1765