1 /*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright © 2001-2007 Red Hat, Inc.
5 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
6 *
7 * Created by David Woodhouse <dwmw2@infradead.org>
8 *
9 * For licensing information, see the file 'LICENCE' in this directory.
10 *
11 */
12
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15 #include <linux/kernel.h>
16 #include <linux/fs.h>
17 #include <linux/time.h>
18 #include <linux/pagemap.h>
19 #include <linux/highmem.h>
20 #include <linux/crc32.h>
21 #include <linux/jffs2.h>
22 #include "nodelist.h"
23
24 static int jffs2_write_end(struct file *filp, struct address_space *mapping,
25 loff_t pos, unsigned len, unsigned copied,
26 struct page *pg, void *fsdata);
27 static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
28 loff_t pos, unsigned len, unsigned flags,
29 struct page **pagep, void **fsdata);
30 static int jffs2_readpage (struct file *filp, struct page *pg);
31
jffs2_fsync(struct file * filp,loff_t start,loff_t end,int datasync)32 int jffs2_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
33 {
34 struct inode *inode = filp->f_mapping->host;
35 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
36 int ret;
37
38 ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
39 if (ret)
40 return ret;
41
42 mutex_lock(&inode->i_mutex);
43 /* Trigger GC to flush any pending writes for this inode */
44 jffs2_flush_wbuf_gc(c, inode->i_ino);
45 mutex_unlock(&inode->i_mutex);
46
47 return 0;
48 }
49
50 const struct file_operations jffs2_file_operations =
51 {
52 .llseek = generic_file_llseek,
53 .open = generic_file_open,
54 .read = do_sync_read,
55 .aio_read = generic_file_aio_read,
56 .write = do_sync_write,
57 .aio_write = generic_file_aio_write,
58 .unlocked_ioctl=jffs2_ioctl,
59 .mmap = generic_file_readonly_mmap,
60 .fsync = jffs2_fsync,
61 .splice_read = generic_file_splice_read,
62 };
63
64 /* jffs2_file_inode_operations */
65
66 const struct inode_operations jffs2_file_inode_operations =
67 {
68 .get_acl = jffs2_get_acl,
69 .setattr = jffs2_setattr,
70 .setxattr = jffs2_setxattr,
71 .getxattr = jffs2_getxattr,
72 .listxattr = jffs2_listxattr,
73 .removexattr = jffs2_removexattr
74 };
75
76 const struct address_space_operations jffs2_file_address_operations =
77 {
78 .readpage = jffs2_readpage,
79 .write_begin = jffs2_write_begin,
80 .write_end = jffs2_write_end,
81 };
82
jffs2_do_readpage_nolock(struct inode * inode,struct page * pg)83 static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
84 {
85 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
86 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
87 unsigned char *pg_buf;
88 int ret;
89
90 jffs2_dbg(2, "%s(): ino #%lu, page at offset 0x%lx\n",
91 __func__, inode->i_ino, pg->index << PAGE_CACHE_SHIFT);
92
93 BUG_ON(!PageLocked(pg));
94
95 pg_buf = kmap(pg);
96 /* FIXME: Can kmap fail? */
97
98 ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
99
100 if (ret) {
101 ClearPageUptodate(pg);
102 SetPageError(pg);
103 } else {
104 SetPageUptodate(pg);
105 ClearPageError(pg);
106 }
107
108 flush_dcache_page(pg);
109 kunmap(pg);
110
111 jffs2_dbg(2, "readpage finished\n");
112 return ret;
113 }
114
jffs2_do_readpage_unlock(struct inode * inode,struct page * pg)115 int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg)
116 {
117 int ret = jffs2_do_readpage_nolock(inode, pg);
118 unlock_page(pg);
119 return ret;
120 }
121
122
jffs2_readpage(struct file * filp,struct page * pg)123 static int jffs2_readpage (struct file *filp, struct page *pg)
124 {
125 struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
126 int ret;
127
128 mutex_lock(&f->sem);
129 ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
130 mutex_unlock(&f->sem);
131 return ret;
132 }
133
jffs2_write_begin(struct file * filp,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)134 static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
135 loff_t pos, unsigned len, unsigned flags,
136 struct page **pagep, void **fsdata)
137 {
138 struct page *pg;
139 struct inode *inode = mapping->host;
140 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
141 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
142 struct jffs2_raw_inode ri;
143 uint32_t alloc_len = 0;
144 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
145 uint32_t pageofs = index << PAGE_CACHE_SHIFT;
146 int ret = 0;
147
148 jffs2_dbg(1, "%s()\n", __func__);
149
150 if (pageofs > inode->i_size) {
151 ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
152 ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
153 if (ret)
154 return ret;
155 }
156
157 mutex_lock(&f->sem);
158 pg = grab_cache_page_write_begin(mapping, index, flags);
159 if (!pg) {
160 if (alloc_len)
161 jffs2_complete_reservation(c);
162 mutex_unlock(&f->sem);
163 return -ENOMEM;
164 }
165 *pagep = pg;
166
167 if (alloc_len) {
168 /* Make new hole frag from old EOF to new page */
169 struct jffs2_full_dnode *fn;
170
171 jffs2_dbg(1, "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
172 (unsigned int)inode->i_size, pageofs);
173
174 memset(&ri, 0, sizeof(ri));
175
176 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
177 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
178 ri.totlen = cpu_to_je32(sizeof(ri));
179 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
180
181 ri.ino = cpu_to_je32(f->inocache->ino);
182 ri.version = cpu_to_je32(++f->highest_version);
183 ri.mode = cpu_to_jemode(inode->i_mode);
184 ri.uid = cpu_to_je16(inode->i_uid);
185 ri.gid = cpu_to_je16(inode->i_gid);
186 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
187 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
188 ri.offset = cpu_to_je32(inode->i_size);
189 ri.dsize = cpu_to_je32(pageofs - inode->i_size);
190 ri.csize = cpu_to_je32(0);
191 ri.compr = JFFS2_COMPR_ZERO;
192 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
193 ri.data_crc = cpu_to_je32(0);
194
195 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL);
196
197 if (IS_ERR(fn)) {
198 ret = PTR_ERR(fn);
199 jffs2_complete_reservation(c);
200 goto out_page;
201 }
202 ret = jffs2_add_full_dnode_to_inode(c, f, fn);
203 if (f->metadata) {
204 jffs2_mark_node_obsolete(c, f->metadata->raw);
205 jffs2_free_full_dnode(f->metadata);
206 f->metadata = NULL;
207 }
208 if (ret) {
209 jffs2_dbg(1, "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n",
210 ret);
211 jffs2_mark_node_obsolete(c, fn->raw);
212 jffs2_free_full_dnode(fn);
213 jffs2_complete_reservation(c);
214 goto out_page;
215 }
216 jffs2_complete_reservation(c);
217 inode->i_size = pageofs;
218 }
219
220 /*
221 * Read in the page if it wasn't already present. Cannot optimize away
222 * the whole page write case until jffs2_write_end can handle the
223 * case of a short-copy.
224 */
225 if (!PageUptodate(pg)) {
226 ret = jffs2_do_readpage_nolock(inode, pg);
227 if (ret)
228 goto out_page;
229 }
230 mutex_unlock(&f->sem);
231 jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags);
232 return ret;
233
234 out_page:
235 unlock_page(pg);
236 page_cache_release(pg);
237 mutex_unlock(&f->sem);
238 return ret;
239 }
240
jffs2_write_end(struct file * filp,struct address_space * mapping,loff_t pos,unsigned len,unsigned copied,struct page * pg,void * fsdata)241 static int jffs2_write_end(struct file *filp, struct address_space *mapping,
242 loff_t pos, unsigned len, unsigned copied,
243 struct page *pg, void *fsdata)
244 {
245 /* Actually commit the write from the page cache page we're looking at.
246 * For now, we write the full page out each time. It sucks, but it's simple
247 */
248 struct inode *inode = mapping->host;
249 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
250 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
251 struct jffs2_raw_inode *ri;
252 unsigned start = pos & (PAGE_CACHE_SIZE - 1);
253 unsigned end = start + copied;
254 unsigned aligned_start = start & ~3;
255 int ret = 0;
256 uint32_t writtenlen = 0;
257
258 jffs2_dbg(1, "%s(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
259 __func__, inode->i_ino, pg->index << PAGE_CACHE_SHIFT,
260 start, end, pg->flags);
261
262 /* We need to avoid deadlock with page_cache_read() in
263 jffs2_garbage_collect_pass(). So the page must be
264 up to date to prevent page_cache_read() from trying
265 to re-lock it. */
266 BUG_ON(!PageUptodate(pg));
267
268 if (end == PAGE_CACHE_SIZE) {
269 /* When writing out the end of a page, write out the
270 _whole_ page. This helps to reduce the number of
271 nodes in files which have many short writes, like
272 syslog files. */
273 aligned_start = 0;
274 }
275
276 ri = jffs2_alloc_raw_inode();
277
278 if (!ri) {
279 jffs2_dbg(1, "%s(): Allocation of raw inode failed\n",
280 __func__);
281 unlock_page(pg);
282 page_cache_release(pg);
283 return -ENOMEM;
284 }
285
286 /* Set the fields that the generic jffs2_write_inode_range() code can't find */
287 ri->ino = cpu_to_je32(inode->i_ino);
288 ri->mode = cpu_to_jemode(inode->i_mode);
289 ri->uid = cpu_to_je16(inode->i_uid);
290 ri->gid = cpu_to_je16(inode->i_gid);
291 ri->isize = cpu_to_je32((uint32_t)inode->i_size);
292 ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
293
294 /* In 2.4, it was already kmapped by generic_file_write(). Doesn't
295 hurt to do it again. The alternative is ifdefs, which are ugly. */
296 kmap(pg);
297
298 ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start,
299 (pg->index << PAGE_CACHE_SHIFT) + aligned_start,
300 end - aligned_start, &writtenlen);
301
302 kunmap(pg);
303
304 if (ret) {
305 /* There was an error writing. */
306 SetPageError(pg);
307 }
308
309 /* Adjust writtenlen for the padding we did, so we don't confuse our caller */
310 writtenlen -= min(writtenlen, (start - aligned_start));
311
312 if (writtenlen) {
313 if (inode->i_size < pos + writtenlen) {
314 inode->i_size = pos + writtenlen;
315 inode->i_blocks = (inode->i_size + 511) >> 9;
316
317 inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
318 }
319 }
320
321 jffs2_free_raw_inode(ri);
322
323 if (start+writtenlen < end) {
324 /* generic_file_write has written more to the page cache than we've
325 actually written to the medium. Mark the page !Uptodate so that
326 it gets reread */
327 jffs2_dbg(1, "%s(): Not all bytes written. Marking page !uptodate\n",
328 __func__);
329 SetPageError(pg);
330 ClearPageUptodate(pg);
331 }
332
333 jffs2_dbg(1, "%s() returning %d\n",
334 __func__, writtenlen > 0 ? writtenlen : ret);
335 unlock_page(pg);
336 page_cache_release(pg);
337 return writtenlen > 0 ? writtenlen : ret;
338 }
339