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12#include <linux/module.h>
13#include <linux/fs.h>
14#include <linux/mm.h>
15#include <linux/pagemap.h>
16#include <linux/highmem.h>
17#include <linux/init.h>
18#include <linux/string.h>
19#include <linux/backing-dev.h>
20#include <linux/ramfs.h>
21#include <linux/pagevec.h>
22#include <linux/mman.h>
23#include <linux/sched.h>
24#include <linux/slab.h>
25
26#include <asm/uaccess.h>
27#include "internal.h"
28
29static int ramfs_nommu_setattr(struct dentry *, struct iattr *);
30
31const struct address_space_operations ramfs_aops = {
32 .readpage = simple_readpage,
33 .write_begin = simple_write_begin,
34 .write_end = simple_write_end,
35 .set_page_dirty = __set_page_dirty_no_writeback,
36};
37
38const struct file_operations ramfs_file_operations = {
39 .mmap = ramfs_nommu_mmap,
40 .get_unmapped_area = ramfs_nommu_get_unmapped_area,
41 .read = do_sync_read,
42 .aio_read = generic_file_aio_read,
43 .write = do_sync_write,
44 .aio_write = generic_file_aio_write,
45 .fsync = noop_fsync,
46 .splice_read = generic_file_splice_read,
47 .splice_write = generic_file_splice_write,
48 .llseek = generic_file_llseek,
49};
50
51const struct inode_operations ramfs_file_inode_operations = {
52 .setattr = ramfs_nommu_setattr,
53 .getattr = simple_getattr,
54};
55
56
57
58
59
60
61
62int ramfs_nommu_expand_for_mapping(struct inode *inode, size_t newsize)
63{
64 unsigned long npages, xpages, loop;
65 struct page *pages;
66 unsigned order;
67 void *data;
68 int ret;
69
70
71 order = get_order(newsize);
72 if (unlikely(order >= MAX_ORDER))
73 return -EFBIG;
74
75 ret = inode_newsize_ok(inode, newsize);
76 if (ret)
77 return ret;
78
79 i_size_write(inode, newsize);
80
81
82
83 pages = alloc_pages(mapping_gfp_mask(inode->i_mapping), order);
84 if (!pages)
85 return -ENOMEM;
86
87
88 xpages = 1UL << order;
89 npages = (newsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
90
91 split_page(pages, order);
92
93
94 for (loop = npages; loop < xpages; loop++)
95 __free_page(pages + loop);
96
97
98 newsize = PAGE_SIZE * npages;
99 data = page_address(pages);
100 memset(data, 0, newsize);
101
102
103 for (loop = 0; loop < npages; loop++) {
104 struct page *page = pages + loop;
105
106 ret = add_to_page_cache_lru(page, inode->i_mapping, loop,
107 GFP_KERNEL);
108 if (ret < 0)
109 goto add_error;
110
111
112 SetPageDirty(page);
113
114 unlock_page(page);
115 }
116
117 return 0;
118
119add_error:
120 while (loop < npages)
121 __free_page(pages + loop++);
122 return ret;
123}
124
125
126
127
128
129static int ramfs_nommu_resize(struct inode *inode, loff_t newsize, loff_t size)
130{
131 int ret;
132
133
134
135 if (size == 0) {
136 if (unlikely(newsize >> 32))
137 return -EFBIG;
138
139 return ramfs_nommu_expand_for_mapping(inode, newsize);
140 }
141
142
143 if (newsize < size) {
144 ret = nommu_shrink_inode_mappings(inode, size, newsize);
145 if (ret < 0)
146 return ret;
147 }
148
149 truncate_setsize(inode, newsize);
150 return 0;
151}
152
153
154
155
156
157
158static int ramfs_nommu_setattr(struct dentry *dentry, struct iattr *ia)
159{
160 struct inode *inode = dentry->d_inode;
161 unsigned int old_ia_valid = ia->ia_valid;
162 int ret = 0;
163
164
165 ret = inode_change_ok(inode, ia);
166 if (ret)
167 return ret;
168
169
170 if (ia->ia_valid & ATTR_SIZE) {
171 loff_t size = inode->i_size;
172
173 if (ia->ia_size != size) {
174 ret = ramfs_nommu_resize(inode, ia->ia_size, size);
175 if (ret < 0 || ia->ia_valid == ATTR_SIZE)
176 goto out;
177 } else {
178
179
180
181 ia->ia_valid |= ATTR_MTIME|ATTR_CTIME;
182 }
183 }
184
185 setattr_copy(inode, ia);
186 out:
187 ia->ia_valid = old_ia_valid;
188 return ret;
189}
190
191
192
193
194
195
196
197
198unsigned long ramfs_nommu_get_unmapped_area(struct file *file,
199 unsigned long addr, unsigned long len,
200 unsigned long pgoff, unsigned long flags)
201{
202 unsigned long maxpages, lpages, nr, loop, ret;
203 struct inode *inode = file->f_path.dentry->d_inode;
204 struct page **pages = NULL, **ptr, *page;
205 loff_t isize;
206
207 if (!(flags & MAP_SHARED))
208 return addr;
209
210
211 lpages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
212 isize = i_size_read(inode);
213
214 ret = -EINVAL;
215 maxpages = (isize + PAGE_SIZE - 1) >> PAGE_SHIFT;
216 if (pgoff >= maxpages)
217 goto out;
218
219 if (maxpages - pgoff < lpages)
220 goto out;
221
222
223 ret = -ENOMEM;
224 pages = kzalloc(lpages * sizeof(struct page *), GFP_KERNEL);
225 if (!pages)
226 goto out_free;
227
228 nr = find_get_pages(inode->i_mapping, pgoff, lpages, pages);
229 if (nr != lpages)
230 goto out_free_pages;
231
232
233 ptr = pages;
234 page = *ptr++;
235 page++;
236 for (loop = lpages; loop > 1; loop--)
237 if (*ptr++ != page++)
238 goto out_free_pages;
239
240
241 ret = (unsigned long) page_address(pages[0]);
242
243out_free_pages:
244 ptr = pages;
245 for (loop = nr; loop > 0; loop--)
246 put_page(*ptr++);
247out_free:
248 kfree(pages);
249out:
250 return ret;
251}
252
253
254
255
256
257int ramfs_nommu_mmap(struct file *file, struct vm_area_struct *vma)
258{
259 if (!(vma->vm_flags & VM_SHARED))
260 return -ENOSYS;
261
262 file_accessed(file);
263 vma->vm_ops = &generic_file_vm_ops;
264 return 0;
265}
266