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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [fs/] [proc/] [link.c] - Blame information for rev 1777

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/*
 *  linux/fs/proc/link.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  /proc link-file handling code
 */
 
/*
 * uClinux revisions for NO_MM
 * Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>,
 *                     The Silver Hammer Group, Ltd.
 */
 
#include <asm/segment.h>
 
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
 
static int proc_readlink(struct inode *, char *, int);
static int proc_follow_link(struct inode *, struct inode *, int, int,
                            struct inode **);
 
/*
 * PLAN9_SEMANTICS won't work any more: it used an ugly hack that broke
 * when the files[] array was updated only after the open code
 */
#undef PLAN9_SEMANTICS
 
/*
 * links can't do much...
 */
static struct file_operations proc_fd_link_operations = {
        NULL,                   /* lseek - default */
        NULL,                   /* read - bad */
        NULL,                   /* write - bad */
        NULL,                   /* readdir - bad */
        NULL,                   /* select - default */
        NULL,                   /* ioctl - default */
        NULL,                   /* mmap */
        NULL,                   /* very special open code */
        NULL,                   /* no special release code */
        NULL                    /* can't fsync */
};
 
struct inode_operations proc_link_inode_operations = {
        &proc_fd_link_operations,/* file-operations */
        NULL,                   /* create */
        NULL,                   /* lookup */
        NULL,                   /* link */
        NULL,                   /* unlink */
        NULL,                   /* symlink */
        NULL,                   /* mkdir */
        NULL,                   /* rmdir */
        NULL,                   /* mknod */
        NULL,                   /* rename */
        proc_readlink,          /* readlink */
        proc_follow_link,       /* follow_link */
        NULL,                   /* readpage */
        NULL,                   /* writepage */
        NULL,                   /* bmap */
        NULL,                   /* truncate */
        NULL                    /* permission */
};
 
 
static int proc_follow_link(struct inode * dir, struct inode * inode,
        int flag, int mode, struct inode ** res_inode)
{
        unsigned int pid, ino;
        struct task_struct * p;
        struct inode * new_inode;
        int i, error;
 
        *res_inode = NULL;
        if (dir)
                iput(dir);
        if (!inode)
                return -ENOENT;
        if ((error = permission(inode, MAY_EXEC)) != 0){
                iput(inode);
                return error;
        }
        ino = inode->i_ino;
        pid = ino >> 16;
        ino &= 0x0000ffff;
        for (i = 0 ; i < NR_TASKS ; i++)
                if ((p = task[i]) && p->pid == pid)
                        break;
        if (i >= NR_TASKS) {
                iput(inode);
                return -ENOENT;
        }
        new_inode = NULL;
        switch (ino) {
                case PROC_PID_CWD:
                        if (!p->fs)
                                break;
                        new_inode = p->fs->pwd;
                        break;
                case PROC_PID_ROOT:
                        if (!p->fs)
                                break;
                        new_inode = p->fs->root;
                        break;
#ifndef NO_MM
                case PROC_PID_EXE: {
                        struct vm_area_struct * vma;
                        if (!p->mm)
                                break;
                        vma = p->mm->mmap;
                        while (vma) {
                                if (vma->vm_flags & VM_EXECUTABLE) {
                                        new_inode = vma->vm_inode;
                                        break;
                                }
                                vma = vma->vm_next;
                        }
                        break;
                }
#else /* NO_MM */
                case PROC_PID_EXE: {
                        new_inode = p->mm->executable;
                        break;
                }
#endif /* NO_MM */
                default:
                        switch (ino >> 8) {
                        case PROC_PID_FD_DIR:
                                if (!p->files)
                                        break;
                                ino &= 0xff;
                                if (ino < NR_OPEN && p->files && p->files->fd[ino]) {
                                        new_inode = p->files->fd[ino]->f_inode;
                                }
                                break;
                        }
        }
        iput(inode);
        if (!new_inode)
                return -ENOENT;
        *res_inode = new_inode;
        new_inode->i_count++;
        return 0;
}
 
static int proc_readlink(struct inode * inode, char * buffer, int buflen)
{
        int i;
        unsigned int dev,ino;
        char buf[64];
 
        if (!S_ISLNK(inode->i_mode)) {
                iput(inode);
                return -EINVAL;
        }
        i = proc_follow_link(NULL, inode, 0, 0, &inode);
        if (i)
                return i;
        if (!inode)
                return -EIO;
        dev = kdev_t_to_nr(inode->i_dev);
        ino = inode->i_ino;
        iput(inode);
        i = sprintf(buf,"[%04x]:%u", dev, ino);
        if (buflen > i)
                buflen = i;
        i = 0;
        while (i < buflen)
                put_user(buf[i++],buffer++);
        return i;
}

Line No.	Rev	Author	Line
1	1628	jcastillo	`/*`
2			`* linux/fs/proc/link.c`
3			`*`
4			`* Copyright (C) 1991, 1992 Linus Torvalds`
5			`*`
6			`* /proc link-file handling code`
7			`*/`
8
9			`/*`
10			`* uClinux revisions for NO_MM`
11			`* Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com>,`
12			`* The Silver Hammer Group, Ltd.`
13			`*/`
14
15			`#include <asm/segment.h>`
16
17			`#include <linux/errno.h>`
18			`#include <linux/sched.h>`
19			`#include <linux/fs.h>`
20			`#include <linux/mm.h>`
21			`#include <linux/proc_fs.h>`
22			`#include <linux/stat.h>`
23
24			`static int proc_readlink(struct inode , char , int);`
25			`static int proc_follow_link(struct inode , struct inode , int, int,`
26			`struct inode **);`
27
28			`/*`
29			`* PLAN9_SEMANTICS won't work any more: it used an ugly hack that broke`
30			`* when the files[] array was updated only after the open code`
31			`*/`
32			`#undef PLAN9_SEMANTICS`
33
34			`/*`
35			`* links can't do much...`
36			`*/`
37			`static struct file_operations proc_fd_link_operations = {`
38			`NULL, /* lseek - default */`
39			`NULL, /* read - bad */`
40			`NULL, /* write - bad */`
41			`NULL, /* readdir - bad */`
42			`NULL, /* select - default */`
43			`NULL, /* ioctl - default */`
44			`NULL, /* mmap */`
45			`NULL, /* very special open code */`
46			`NULL, /* no special release code */`
47			`NULL /* can't fsync */`
48			`};`
49
50			`struct inode_operations proc_link_inode_operations = {`
51			`&proc_fd_link_operations,/* file-operations */`
52			`NULL, /* create */`
53			`NULL, /* lookup */`
54			`NULL, /* link */`
55			`NULL, /* unlink */`
56			`NULL, /* symlink */`
57			`NULL, /* mkdir */`
58			`NULL, /* rmdir */`
59			`NULL, /* mknod */`
60			`NULL, /* rename */`
61			`proc_readlink, /* readlink */`
62			`proc_follow_link, /* follow_link */`
63			`NULL, /* readpage */`
64			`NULL, /* writepage */`
65			`NULL, /* bmap */`
66			`NULL, /* truncate */`
67			`NULL /* permission */`
68			`};`
69
70
71			`static int proc_follow_link(struct inode * dir, struct inode * inode,`
72			`int flag, int mode, struct inode ** res_inode)`
73			`{`
74			`unsigned int pid, ino;`
75			`struct task_struct * p;`
76			`struct inode * new_inode;`
77			`int i, error;`
78
79			`*res_inode = NULL;`
80			`if (dir)`
81			`iput(dir);`
82			`if (!inode)`
83			`return -ENOENT;`
84			`if ((error = permission(inode, MAY_EXEC)) != 0){`
85			`iput(inode);`
86			`return error;`
87			`}`
88			`ino = inode->i_ino;`
89			`pid = ino >> 16;`
90			`ino &= 0x0000ffff;`
91			`for (i = 0 ; i < NR_TASKS ; i++)`
92			`if ((p = task[i]) && p->pid == pid)`
93			`break;`
94			`if (i >= NR_TASKS) {`
95			`iput(inode);`
96			`return -ENOENT;`
97			`}`
98			`new_inode = NULL;`
99			`switch (ino) {`
100			`case PROC_PID_CWD:`
101			`if (!p->fs)`
102			`break;`
103			`new_inode = p->fs->pwd;`
104			`break;`
105			`case PROC_PID_ROOT:`
106			`if (!p->fs)`
107			`break;`
108			`new_inode = p->fs->root;`
109			`break;`
110			`#ifndef NO_MM`
111			`case PROC_PID_EXE: {`
112			`struct vm_area_struct * vma;`
113			`if (!p->mm)`
114			`break;`
115			`vma = p->mm->mmap;`
116			`while (vma) {`
117			`if (vma->vm_flags & VM_EXECUTABLE) {`
118			`new_inode = vma->vm_inode;`
119			`break;`
120			`}`
121			`vma = vma->vm_next;`
122			`}`
123			`break;`
124			`}`
125			`#else /* NO_MM */`
126			`case PROC_PID_EXE: {`
127			`new_inode = p->mm->executable;`
128			`break;`
129			`}`
130			`#endif /* NO_MM */`
131			`default:`
132			`switch (ino >> 8) {`
133			`case PROC_PID_FD_DIR:`
134			`if (!p->files)`
135			`break;`
136			`ino &= 0xff;`
137			`if (ino < NR_OPEN && p->files && p->files->fd[ino]) {`
138			`new_inode = p->files->fd[ino]->f_inode;`
139			`}`
140			`break;`
141			`}`
142			`}`
143			`iput(inode);`
144			`if (!new_inode)`
145			`return -ENOENT;`
146			`*res_inode = new_inode;`
147			`new_inode->i_count++;`
148			`return 0;`
149			`}`
150
151			`static int proc_readlink(struct inode * inode, char * buffer, int buflen)`
152			`{`
153			`int i;`
154			`unsigned int dev,ino;`
155			`char buf[64];`
156
157			`if (!S_ISLNK(inode->i_mode)) {`
158			`iput(inode);`
159			`return -EINVAL;`
160			`}`
161			`i = proc_follow_link(NULL, inode, 0, 0, &inode);`
162			`if (i)`
163			`return i;`
164			`if (!inode)`
165			`return -EIO;`
166			`dev = kdev_t_to_nr(inode->i_dev);`
167			`ino = inode->i_ino;`
168			`iput(inode);`
169			`i = sprintf(buf,"[%04x]:%u", dev, ino);`
170			`if (buflen > i)`
171			`buflen = i;`
172			`i = 0;`
173			`while (i < buflen)`
174			`put_user(buf[i++],buffer++);`
175			`return i;`
176			`}`

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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [fs/] [proc/] [link.c] - Blame information for rev 1777