1 /*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright © 2001-2007 Red Hat, Inc.
5 *
6 * Created by David Woodhouse <dwmw2@infradead.org>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/fs.h>
15 #include <linux/time.h>
16 #include <linux/pagemap.h>
17 #include <linux/highmem.h>
18 #include <linux/crc32.h>
19 #include <linux/jffs2.h>
20 #include "nodelist.h"
21
22 static int jffs2_write_end(struct file *filp, struct address_space *mapping,
23 loff_t pos, unsigned len, unsigned copied,
24 struct page *pg, void *fsdata);
25 static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
26 loff_t pos, unsigned len, unsigned flags,
27 struct page **pagep, void **fsdata);
28 static int jffs2_readpage (struct file *filp, struct page *pg);
29
30 int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync)
31 {
32 struct inode *inode = dentry->d_inode;
33 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
34
35 /* Trigger GC to flush any pending writes for this inode */
36 jffs2_flush_wbuf_gc(c, inode->i_ino);
37
38 return 0;
39 }
40
41 const struct file_operations jffs2_file_operations =
42 {
43 .llseek = generic_file_llseek,
44 .open = generic_file_open,
45 .read = do_sync_read,
46 .aio_read = generic_file_aio_read,
47 .write = do_sync_write,
48 .aio_write = generic_file_aio_write,
49 .ioctl = jffs2_ioctl,
50 .mmap = generic_file_readonly_mmap,
51 .fsync = jffs2_fsync,
52 .splice_read = generic_file_splice_read,
53 };
54
55 /* jffs2_file_inode_operations */
56
57 const struct inode_operations jffs2_file_inode_operations =
58 {
59 .permission = jffs2_permission,
60 .setattr = jffs2_setattr,
61 .setxattr = jffs2_setxattr,
62 .getxattr = jffs2_getxattr,
63 .listxattr = jffs2_listxattr,
64 .removexattr = jffs2_removexattr
65 };
66
67 const struct address_space_operations jffs2_file_address_operations =
68 {
69 .readpage = jffs2_readpage,
70 .write_begin = jffs2_write_begin,
71 .write_end = jffs2_write_end,
72 };
73
74 static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
75 {
76 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
77 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
78 unsigned char *pg_buf;
79 int ret;
80
81 D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT));
82
83 BUG_ON(!PageLocked(pg));
84
85 pg_buf = kmap(pg);
86 /* FIXME: Can kmap fail? */
87
88 ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
89
90 if (ret) {
91 ClearPageUptodate(pg);
92 SetPageError(pg);
93 } else {
94 SetPageUptodate(pg);
95 ClearPageError(pg);
96 }
97
98 flush_dcache_page(pg);
99 kunmap(pg);
100
101 D2(printk(KERN_DEBUG "readpage finished\n"));
102 return 0;
103 }
104
105 int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg)
106 {
107 int ret = jffs2_do_readpage_nolock(inode, pg);
108 unlock_page(pg);
109 return ret;
110 }
111
112
113 static int jffs2_readpage (struct file *filp, struct page *pg)
114 {
115 struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
116 int ret;
117
118 down(&f->sem);
119 ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
120 up(&f->sem);
121 return ret;
122 }
123
124 static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
125 loff_t pos, unsigned len, unsigned flags,
126 struct page **pagep, void **fsdata)
127 {
128 struct page *pg;
129 struct inode *inode = mapping->host;
130 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
131 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
132 uint32_t pageofs = index << PAGE_CACHE_SHIFT;
133 int ret = 0;
134
135 pg = __grab_cache_page(mapping, index);
136 if (!pg)
137 return -ENOMEM;
138 *pagep = pg;
139
140 D1(printk(KERN_DEBUG "jffs2_write_begin()\n"));
141
142 if (pageofs > inode->i_size) {
143 /* Make new hole frag from old EOF to new page */
144 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
145 struct jffs2_raw_inode ri;
146 struct jffs2_full_dnode *fn;
147 uint32_t alloc_len;
148
149 D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
150 (unsigned int)inode->i_size, pageofs));
151
152 ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
153 ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
154 if (ret)
155 goto out_page;
156
157 down(&f->sem);
158 memset(&ri, 0, sizeof(ri));
159
160 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
161 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
162 ri.totlen = cpu_to_je32(sizeof(ri));
163 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
164
165 ri.ino = cpu_to_je32(f->inocache->ino);
166 ri.version = cpu_to_je32(++f->highest_version);
167 ri.mode = cpu_to_jemode(inode->i_mode);
168 ri.uid = cpu_to_je16(inode->i_uid);
169 ri.gid = cpu_to_je16(inode->i_gid);
170 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
171 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
172 ri.offset = cpu_to_je32(inode->i_size);
173 ri.dsize = cpu_to_je32(pageofs - inode->i_size);
174 ri.csize = cpu_to_je32(0);
175 ri.compr = JFFS2_COMPR_ZERO;
176 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
177 ri.data_crc = cpu_to_je32(0);
178
179 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL);
180
181 if (IS_ERR(fn)) {
182 ret = PTR_ERR(fn);
183 jffs2_complete_reservation(c);
184 up(&f->sem);
185 goto out_page;
186 }
187 ret = jffs2_add_full_dnode_to_inode(c, f, fn);
188 if (f->metadata) {
189 jffs2_mark_node_obsolete(c, f->metadata->raw);
190 jffs2_free_full_dnode(f->metadata);
191 f->metadata = NULL;
192 }
193 if (ret) {
194 D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n", ret));
195 jffs2_mark_node_obsolete(c, fn->raw);
196 jffs2_free_full_dnode(fn);
197 jffs2_complete_reservation(c);
198 up(&f->sem);
199 goto out_page;
200 }
201 jffs2_complete_reservation(c);
202 inode->i_size = pageofs;
203 up(&f->sem);
204 }
205
206 /*
207 * Read in the page if it wasn't already present. Cannot optimize away
208 * the whole page write case until jffs2_write_end can handle the
209 * case of a short-copy.
210 */
211 if (!PageUptodate(pg)) {
212 down(&f->sem);
213 ret = jffs2_do_readpage_nolock(inode, pg);
214 up(&f->sem);
215 if (ret)
216 goto out_page;
217 }
218 D1(printk(KERN_DEBUG "end write_begin(). pg->flags %lx\n", pg->flags));
219 return ret;
220
221 out_page:
222 unlock_page(pg);
223 page_cache_release(pg);
224 return ret;
225 }
226
227 static int jffs2_write_end(struct file *filp, struct address_space *mapping,
228 loff_t pos, unsigned len, unsigned copied,
229 struct page *pg, void *fsdata)
230 {
231 /* Actually commit the write from the page cache page we're looking at.
232 * For now, we write the full page out each time. It sucks, but it's simple
233 */
234 struct inode *inode = mapping->host;
235 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
236 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
237 struct jffs2_raw_inode *ri;
238 unsigned start = pos & (PAGE_CACHE_SIZE - 1);
239 unsigned end = start + copied;
240 unsigned aligned_start = start & ~3;
241 int ret = 0;
242 uint32_t writtenlen = 0;
243
244 D1(printk(KERN_DEBUG "jffs2_write_end(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
245 inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags));
246
247 /* We need to avoid deadlock with page_cache_read() in
248 jffs2_garbage_collect_pass(). So the page must be
249 up to date to prevent page_cache_read() from trying
250 to re-lock it. */
251 BUG_ON(!PageUptodate(pg));
252
253 if (end == PAGE_CACHE_SIZE) {
254 /* When writing out the end of a page, write out the
255 _whole_ page. This helps to reduce the number of
256 nodes in files which have many short writes, like
257 syslog files. */
258 aligned_start = 0;
259 }
260
261 ri = jffs2_alloc_raw_inode();
262
263 if (!ri) {
264 D1(printk(KERN_DEBUG "jffs2_write_end(): Allocation of raw inode failed\n"));
265 unlock_page(pg);
266 page_cache_release(pg);
267 return -ENOMEM;
268 }
269
270 /* Set the fields that the generic jffs2_write_inode_range() code can't find */
271 ri->ino = cpu_to_je32(inode->i_ino);
272 ri->mode = cpu_to_jemode(inode->i_mode);
273 ri->uid = cpu_to_je16(inode->i_uid);
274 ri->gid = cpu_to_je16(inode->i_gid);
275 ri->isize = cpu_to_je32((uint32_t)inode->i_size);
276 ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
277
278 /* In 2.4, it was already kmapped by generic_file_write(). Doesn't
279 hurt to do it again. The alternative is ifdefs, which are ugly. */
280 kmap(pg);
281
282 ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start,
283 (pg->index << PAGE_CACHE_SHIFT) + aligned_start,
284 end - aligned_start, &writtenlen);
285
286 kunmap(pg);
287
288 if (ret) {
289 /* There was an error writing. */
290 SetPageError(pg);
291 }
292
293 /* Adjust writtenlen for the padding we did, so we don't confuse our caller */
294 writtenlen -= min(writtenlen, (start - aligned_start));
295
296 if (writtenlen) {
297 if (inode->i_size < pos + writtenlen) {
298 inode->i_size = pos + writtenlen;
299 inode->i_blocks = (inode->i_size + 511) >> 9;
300
301 inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
302 }
303 }
304
305 jffs2_free_raw_inode(ri);
306
307 if (start+writtenlen < end) {
308 /* generic_file_write has written more to the page cache than we've
309 actually written to the medium. Mark the page !Uptodate so that
310 it gets reread */
311 D1(printk(KERN_DEBUG "jffs2_write_end(): Not all bytes written. Marking page !uptodate\n"));
312 SetPageError(pg);
313 ClearPageUptodate(pg);
314 }
315
316 D1(printk(KERN_DEBUG "jffs2_write_end() returning %d\n",
317 writtenlen > 0 ? writtenlen : ret));
318 unlock_page(pg);
319 page_cache_release(pg);
320 return writtenlen > 0 ? writtenlen : ret;
321 }
322
|
This page was automatically generated by the
LXR engine.
|