1 |
kumaneko |
111 |
/* |
2 |
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* fs/syaoran_2.6.c |
3 |
|
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* |
4 |
|
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* Implementation of the Tamper-Proof Device Filesystem. |
5 |
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* |
6 |
kumaneko |
856 |
* Portions Copyright (C) 2005-2008 NTT DATA CORPORATION |
7 |
kumaneko |
111 |
* |
8 |
kumaneko |
1817 |
* Version: 1.6.5 2008/11/11 |
9 |
kumaneko |
111 |
* |
10 |
|
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* This file is applicable to 2.6.11 and later. |
11 |
|
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* See README.ccs for ChangeLog. |
12 |
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* This filesystem is developed using the ramfs implementation. |
13 |
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* |
14 |
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*/ |
15 |
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/* |
16 |
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* Resizable simple ram filesystem for Linux. |
17 |
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* |
18 |
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* Copyright (C) 2000 Linus Torvalds. |
19 |
|
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* 2000 Transmeta Corp. |
20 |
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* |
21 |
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* Usage limits added by David Gibson, Linuxcare Australia. |
22 |
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* This file is released under the GPL. |
23 |
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*/ |
24 |
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|
25 |
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/* |
26 |
|
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* NOTE! This filesystem is probably most useful |
27 |
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* not as a real filesystem, but as an example of |
28 |
|
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* how virtual filesystems can be written. |
29 |
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* |
30 |
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* It doesn't get much simpler than this. Consider |
31 |
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* that this file implements the full semantics of |
32 |
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* a POSIX-compliant read-write filesystem. |
33 |
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* |
34 |
|
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* Note in particular how the filesystem does not |
35 |
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* need to implement any data structures of its own |
36 |
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* to keep track of the virtual data: using the VFS |
37 |
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* caches is sufficient. |
38 |
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*/ |
39 |
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|
40 |
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#include <linux/module.h> |
41 |
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#include <linux/fs.h> |
42 |
|
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#include <linux/pagemap.h> |
43 |
|
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#include <linux/highmem.h> |
44 |
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#include <linux/init.h> |
45 |
|
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#include <linux/string.h> |
46 |
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#include <linux/smp_lock.h> |
47 |
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#include <linux/backing-dev.h> |
48 |
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|
49 |
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#include <asm/uaccess.h> |
50 |
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|
51 |
|
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#include <linux/namei.h> |
52 |
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#include <linux/version.h> |
53 |
kumaneko |
442 |
#include <linux/sched.h> |
54 |
kumaneko |
614 |
#include <linux/mm.h> |
55 |
kumaneko |
111 |
|
56 |
|
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static struct super_operations syaoran_ops; |
57 |
|
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static struct address_space_operations syaoran_aops; |
58 |
|
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static struct inode_operations syaoran_file_inode_operations; |
59 |
|
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static struct inode_operations syaoran_dir_inode_operations; |
60 |
|
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static struct inode_operations syaoran_symlink_inode_operations; |
61 |
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static struct file_operations syaoran_file_operations; |
62 |
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|
63 |
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static struct backing_dev_info syaoran_backing_dev_info = { |
64 |
kumaneko |
1052 |
.ra_pages = 0, /* No readahead */ |
65 |
|
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#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 12) |
66 |
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.memory_backed = 1, /* Does not contribute to dirty memory */ |
67 |
kumaneko |
111 |
#else |
68 |
kumaneko |
1052 |
.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK | |
69 |
|
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BDI_CAP_MAP_DIRECT | BDI_CAP_MAP_COPY | |
70 |
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BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | |
71 |
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BDI_CAP_EXEC_MAP, |
72 |
kumaneko |
111 |
#endif |
73 |
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}; |
74 |
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|
75 |
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#include <linux/syaoran.h> |
76 |
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|
77 |
kumaneko |
1052 |
static struct inode *syaoran_get_inode(struct super_block *sb, int mode, |
78 |
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dev_t dev) |
79 |
kumaneko |
111 |
{ |
80 |
kumaneko |
1052 |
struct inode *inode = new_inode(sb); |
81 |
kumaneko |
111 |
|
82 |
|
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if (inode) { |
83 |
|
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inode->i_mode = mode; |
84 |
|
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inode->i_uid = current->fsuid; |
85 |
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inode->i_gid = current->fsgid; |
86 |
kumaneko |
1052 |
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 19) |
87 |
kumaneko |
1715 |
#ifndef HAVE_NO_I_BLKSIZE_IN_INODE |
88 |
kumaneko |
111 |
inode->i_blksize = PAGE_CACHE_SIZE; |
89 |
|
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#endif |
90 |
kumaneko |
1458 |
#endif |
91 |
kumaneko |
111 |
inode->i_blocks = 0; |
92 |
|
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inode->i_mapping->a_ops = &syaoran_aops; |
93 |
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inode->i_mapping->backing_dev_info = &syaoran_backing_dev_info; |
94 |
kumaneko |
1052 |
inode->i_ctime = CURRENT_TIME; |
95 |
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inode->i_mtime = inode->i_ctime; |
96 |
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inode->i_atime = inode->i_mtime; |
97 |
kumaneko |
111 |
switch (mode & S_IFMT) { |
98 |
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default: |
99 |
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init_special_inode(inode, mode, dev); |
100 |
kumaneko |
1052 |
if (S_ISBLK(mode)) |
101 |
|
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inode->i_fop = &wrapped_def_blk_fops; |
102 |
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else if (S_ISCHR(mode)) |
103 |
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inode->i_fop = &wrapped_def_chr_fops; |
104 |
kumaneko |
111 |
inode->i_op = &syaoran_file_inode_operations; |
105 |
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break; |
106 |
|
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case S_IFREG: |
107 |
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inode->i_op = &syaoran_file_inode_operations; |
108 |
|
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inode->i_fop = &syaoran_file_operations; |
109 |
|
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break; |
110 |
|
|
case S_IFDIR: |
111 |
|
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inode->i_op = &syaoran_dir_inode_operations; |
112 |
|
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inode->i_fop = &simple_dir_operations; |
113 |
kumaneko |
1052 |
/* |
114 |
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* directory inodes start off with i_nlink == 2 |
115 |
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* (for "." entry) |
116 |
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*/ |
117 |
kumaneko |
111 |
inode->i_nlink++; |
118 |
|
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break; |
119 |
|
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case S_IFLNK: |
120 |
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inode->i_op = &syaoran_symlink_inode_operations; |
121 |
|
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break; |
122 |
|
|
} |
123 |
|
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} |
124 |
|
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return inode; |
125 |
|
|
} |
126 |
|
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|
127 |
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/* |
128 |
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* File creation. Allocate an inode, and we're done.. |
129 |
|
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*/ |
130 |
|
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/* SMP-safe */ |
131 |
kumaneko |
1052 |
static int syaoran_mknod(struct inode *dir, struct dentry *dentry, int mode, |
132 |
|
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dev_t dev) |
133 |
kumaneko |
111 |
{ |
134 |
kumaneko |
1052 |
struct inode *inode; |
135 |
kumaneko |
111 |
int error = -ENOSPC; |
136 |
kumaneko |
1052 |
if (syaoran_may_create_node(dentry, mode, dev) < 0) |
137 |
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return -EPERM; |
138 |
kumaneko |
111 |
inode = syaoran_get_inode(dir->i_sb, mode, dev); |
139 |
|
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if (inode) { |
140 |
|
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if (dir->i_mode & S_ISGID) { |
141 |
|
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inode->i_gid = dir->i_gid; |
142 |
|
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if (S_ISDIR(mode)) |
143 |
|
|
inode->i_mode |= S_ISGID; |
144 |
|
|
} |
145 |
|
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d_instantiate(dentry, inode); |
146 |
|
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dget(dentry); /* Extra count - pin the dentry in core */ |
147 |
|
|
error = 0; |
148 |
|
|
} |
149 |
|
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return error; |
150 |
|
|
} |
151 |
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|
152 |
kumaneko |
1052 |
static int syaoran_mkdir(struct inode *dir, struct dentry *dentry, int mode) |
153 |
kumaneko |
111 |
{ |
154 |
|
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int retval = syaoran_mknod(dir, dentry, mode | S_IFDIR, 0); |
155 |
|
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if (!retval) |
156 |
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dir->i_nlink++; |
157 |
|
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return retval; |
158 |
|
|
} |
159 |
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|
160 |
kumaneko |
1052 |
static int syaoran_create(struct inode *dir, struct dentry *dentry, int mode, |
161 |
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struct nameidata *nd) |
162 |
kumaneko |
111 |
{ |
163 |
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return syaoran_mknod(dir, dentry, mode | S_IFREG, 0); |
164 |
|
|
} |
165 |
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|
166 |
kumaneko |
1052 |
static int syaoran_symlink(struct inode *dir, struct dentry *dentry, |
167 |
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const char *symname) |
168 |
kumaneko |
111 |
{ |
169 |
|
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struct inode *inode; |
170 |
|
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int error = -ENOSPC; |
171 |
kumaneko |
1052 |
if (syaoran_may_create_node(dentry, S_IFLNK, 0) < 0) |
172 |
|
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return -EPERM; |
173 |
kumaneko |
111 |
inode = syaoran_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0); |
174 |
|
|
if (inode) { |
175 |
|
|
int l = strlen(symname)+1; |
176 |
|
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error = page_symlink(inode, symname, l); |
177 |
|
|
if (!error) { |
178 |
|
|
if (dir->i_mode & S_ISGID) |
179 |
|
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inode->i_gid = dir->i_gid; |
180 |
|
|
d_instantiate(dentry, inode); |
181 |
|
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dget(dentry); |
182 |
|
|
} else |
183 |
|
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iput(inode); |
184 |
|
|
} |
185 |
|
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return error; |
186 |
|
|
} |
187 |
|
|
|
188 |
kumaneko |
1052 |
static int syaoran_link(struct dentry *old_dentry, struct inode *dir, |
189 |
|
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struct dentry *dentry) |
190 |
kumaneko |
111 |
{ |
191 |
|
|
struct inode *inode = old_dentry->d_inode; |
192 |
kumaneko |
1052 |
if (!inode || syaoran_may_create_node(dentry, inode->i_mode, |
193 |
|
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inode->i_rdev) < 0) |
194 |
|
|
return -EPERM; |
195 |
kumaneko |
111 |
return simple_link(old_dentry, dir, dentry); |
196 |
|
|
} |
197 |
|
|
|
198 |
kumaneko |
1052 |
static int syaoran_unlink(struct inode *dir, struct dentry *dentry) |
199 |
kumaneko |
111 |
{ |
200 |
kumaneko |
1052 |
if (syaoran_may_modify_node(dentry, MAY_DELETE) < 0) |
201 |
|
|
return -EPERM; |
202 |
kumaneko |
111 |
return simple_unlink(dir, dentry); |
203 |
|
|
} |
204 |
|
|
|
205 |
kumaneko |
1052 |
static int syaoran_rename(struct inode *old_dir, struct dentry *old_dentry, |
206 |
|
|
struct inode *new_dir, struct dentry *new_dentry) |
207 |
kumaneko |
111 |
{ |
208 |
|
|
struct inode *inode = old_dentry->d_inode; |
209 |
kumaneko |
1052 |
if (!inode || syaoran_may_modify_node(old_dentry, MAY_DELETE) < 0 || |
210 |
|
|
syaoran_may_create_node(new_dentry, inode->i_mode, |
211 |
|
|
inode->i_rdev) < 0) |
212 |
|
|
return -EPERM; |
213 |
kumaneko |
111 |
return simple_rename(old_dir, old_dentry, new_dir, new_dentry); |
214 |
|
|
} |
215 |
|
|
|
216 |
|
|
static int syaoran_rmdir(struct inode *dir, struct dentry *dentry) |
217 |
|
|
{ |
218 |
kumaneko |
1052 |
if (syaoran_may_modify_node(dentry, MAY_DELETE) < 0) |
219 |
|
|
return -EPERM; |
220 |
kumaneko |
111 |
return simple_rmdir(dir, dentry); |
221 |
|
|
} |
222 |
|
|
|
223 |
kumaneko |
1052 |
static int syaoran_setattr(struct dentry *dentry, struct iattr *attr) |
224 |
kumaneko |
111 |
{ |
225 |
|
|
struct inode *inode = dentry->d_inode; |
226 |
|
|
int error = inode_change_ok(inode, attr); |
227 |
|
|
if (!error) { |
228 |
|
|
unsigned int ia_valid = attr->ia_valid; |
229 |
|
|
unsigned int flags = 0; |
230 |
kumaneko |
1052 |
if (ia_valid & (ATTR_UID | ATTR_GID)) |
231 |
|
|
flags |= MAY_CHOWN; |
232 |
|
|
if (ia_valid & ATTR_MODE) |
233 |
|
|
flags |= MAY_CHMOD; |
234 |
|
|
if (syaoran_may_modify_node(dentry, flags) < 0) |
235 |
|
|
return -EPERM; |
236 |
|
|
if (!error) |
237 |
|
|
error = inode_setattr(inode, attr); |
238 |
kumaneko |
111 |
} |
239 |
|
|
return error; |
240 |
|
|
} |
241 |
|
|
|
242 |
kumaneko |
1052 |
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24) |
243 |
kumaneko |
111 |
static struct address_space_operations syaoran_aops = { |
244 |
|
|
.readpage = simple_readpage, |
245 |
|
|
.prepare_write = simple_prepare_write, |
246 |
|
|
.commit_write = simple_commit_write |
247 |
|
|
}; |
248 |
kumaneko |
614 |
#else |
249 |
kumaneko |
808 |
static int syaoran_set_page_dirty_no_writeback(struct page *page) |
250 |
|
|
{ |
251 |
|
|
if (!PageDirty(page)) |
252 |
|
|
SetPageDirty(page); |
253 |
|
|
return 0; |
254 |
|
|
} |
255 |
kumaneko |
614 |
static struct address_space_operations syaoran_aops = { |
256 |
kumaneko |
708 |
.readpage = simple_readpage, |
257 |
|
|
.write_begin = simple_write_begin, |
258 |
|
|
.write_end = simple_write_end, |
259 |
kumaneko |
808 |
.set_page_dirty = syaoran_set_page_dirty_no_writeback, |
260 |
kumaneko |
614 |
}; |
261 |
|
|
#endif |
262 |
kumaneko |
111 |
|
263 |
|
|
static struct file_operations syaoran_file_operations = { |
264 |
kumaneko |
1052 |
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 19) |
265 |
|
|
.read = generic_file_read, |
266 |
|
|
.write = generic_file_write, |
267 |
kumaneko |
111 |
#else |
268 |
kumaneko |
1052 |
.aio_read = generic_file_aio_read, |
269 |
|
|
.read = do_sync_read, |
270 |
|
|
.aio_write = generic_file_aio_write, |
271 |
|
|
.write = do_sync_write, |
272 |
kumaneko |
111 |
#endif |
273 |
kumaneko |
1052 |
.mmap = generic_file_mmap, |
274 |
|
|
.fsync = simple_sync_file, |
275 |
|
|
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 23) |
276 |
|
|
.sendfile = generic_file_sendfile, |
277 |
kumaneko |
316 |
#else |
278 |
kumaneko |
1052 |
.splice_read = generic_file_splice_read, |
279 |
kumaneko |
316 |
#endif |
280 |
kumaneko |
1052 |
.llseek = generic_file_llseek, |
281 |
kumaneko |
111 |
}; |
282 |
|
|
|
283 |
|
|
static struct inode_operations syaoran_file_inode_operations = { |
284 |
|
|
.getattr = simple_getattr, |
285 |
|
|
.setattr = syaoran_setattr, |
286 |
|
|
}; |
287 |
|
|
|
288 |
|
|
static struct inode_operations syaoran_dir_inode_operations = { |
289 |
|
|
.create = syaoran_create, |
290 |
|
|
.lookup = simple_lookup, |
291 |
|
|
.link = syaoran_link, |
292 |
|
|
.unlink = syaoran_unlink, |
293 |
|
|
.symlink = syaoran_symlink, |
294 |
|
|
.mkdir = syaoran_mkdir, |
295 |
|
|
.rmdir = syaoran_rmdir, |
296 |
|
|
.mknod = syaoran_mknod, |
297 |
|
|
.rename = syaoran_rename, |
298 |
|
|
.setattr = syaoran_setattr, |
299 |
|
|
}; |
300 |
|
|
|
301 |
|
|
static struct inode_operations syaoran_symlink_inode_operations = { |
302 |
|
|
.readlink = generic_readlink, |
303 |
|
|
.follow_link = page_follow_link_light, |
304 |
|
|
.put_link = page_put_link, |
305 |
|
|
.setattr = syaoran_setattr, |
306 |
|
|
}; |
307 |
|
|
|
308 |
|
|
static struct super_operations syaoran_ops = { |
309 |
|
|
.statfs = simple_statfs, |
310 |
|
|
.drop_inode = generic_delete_inode, |
311 |
|
|
.put_super = syaoran_put_super, |
312 |
|
|
}; |
313 |
|
|
|
314 |
kumaneko |
1052 |
static int syaoran_fill_super(struct super_block *sb, void *data, int silent) |
315 |
kumaneko |
111 |
{ |
316 |
kumaneko |
1052 |
struct inode *inode; |
317 |
|
|
struct dentry *root; |
318 |
kumaneko |
111 |
|
319 |
|
|
sb->s_maxbytes = MAX_LFS_FILESIZE; |
320 |
|
|
sb->s_blocksize = PAGE_CACHE_SIZE; |
321 |
|
|
sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
322 |
|
|
sb->s_magic = SYAORAN_MAGIC; |
323 |
|
|
sb->s_op = &syaoran_ops; |
324 |
kumaneko |
1052 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 9) |
325 |
kumaneko |
111 |
sb->s_time_gran = 1; |
326 |
|
|
#endif |
327 |
|
|
{ |
328 |
kumaneko |
1052 |
int error = syaoran_initialize(sb, data); |
329 |
|
|
if (error < 0) |
330 |
|
|
return error; |
331 |
kumaneko |
111 |
} |
332 |
|
|
inode = syaoran_get_inode(sb, S_IFDIR | 0755, 0); |
333 |
|
|
if (!inode) |
334 |
|
|
return -ENOMEM; |
335 |
|
|
|
336 |
|
|
root = d_alloc_root(inode); |
337 |
|
|
if (!root) { |
338 |
|
|
iput(inode); |
339 |
|
|
return -ENOMEM; |
340 |
|
|
} |
341 |
|
|
sb->s_root = root; |
342 |
kumaneko |
1052 |
syaoran_make_initial_nodes(sb); |
343 |
kumaneko |
111 |
return 0; |
344 |
|
|
} |
345 |
|
|
|
346 |
kumaneko |
1052 |
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 18) |
347 |
kumaneko |
808 |
static struct super_block *syaoran_get_sb(struct file_system_type *fs_type, |
348 |
kumaneko |
1052 |
int flags, const char *dev_name, |
349 |
|
|
void *data) |
350 |
kumaneko |
111 |
{ |
351 |
|
|
return get_sb_nodev(fs_type, flags, data, syaoran_fill_super); |
352 |
|
|
} |
353 |
|
|
#else |
354 |
kumaneko |
808 |
static int syaoran_get_sb(struct file_system_type *fs_type, |
355 |
kumaneko |
1052 |
int flags, const char *dev_name, void *data, |
356 |
|
|
struct vfsmount *mnt) |
357 |
kumaneko |
111 |
{ |
358 |
|
|
return get_sb_nodev(fs_type, flags, data, syaoran_fill_super, mnt); |
359 |
|
|
} |
360 |
|
|
#endif |
361 |
|
|
|
362 |
|
|
static struct file_system_type syaoran_fs_type = { |
363 |
|
|
.owner = THIS_MODULE, |
364 |
|
|
.name = "syaoran", |
365 |
|
|
.get_sb = syaoran_get_sb, |
366 |
|
|
.kill_sb = kill_litter_super, |
367 |
|
|
}; |
368 |
|
|
|
369 |
|
|
static int __init init_syaoran_fs(void) |
370 |
|
|
{ |
371 |
|
|
return register_filesystem(&syaoran_fs_type); |
372 |
|
|
} |
373 |
|
|
|
374 |
|
|
static void __exit exit_syaoran_fs(void) |
375 |
|
|
{ |
376 |
|
|
unregister_filesystem(&syaoran_fs_type); |
377 |
|
|
} |
378 |
|
|
|
379 |
kumaneko |
808 |
module_init(init_syaoran_fs); |
380 |
|
|
module_exit(exit_syaoran_fs); |
381 |
kumaneko |
111 |
|
382 |
|
|
MODULE_LICENSE("GPL"); |