]>
Commit | Line | Data |
---|---|---|
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 | ||
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 = file_write_and_wait_range(filp, start, end); | |
39 | if (ret) | |
40 | return ret; | |
41 | ||
42 | inode_lock(inode); | |
43 | /* Trigger GC to flush any pending writes for this inode */ | |
44 | jffs2_flush_wbuf_gc(c, inode->i_ino); | |
45 | inode_unlock(inode); | |
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_iter = generic_file_read_iter, | |
55 | .write_iter = generic_file_write_iter, | |
56 | .unlocked_ioctl=jffs2_ioctl, | |
57 | .mmap = generic_file_readonly_mmap, | |
58 | .fsync = jffs2_fsync, | |
59 | .splice_read = generic_file_splice_read, | |
60 | }; | |
61 | ||
62 | /* jffs2_file_inode_operations */ | |
63 | ||
64 | const struct inode_operations jffs2_file_inode_operations = | |
65 | { | |
66 | .get_acl = jffs2_get_acl, | |
67 | .set_acl = jffs2_set_acl, | |
68 | .setattr = jffs2_setattr, | |
69 | .listxattr = jffs2_listxattr, | |
70 | }; | |
71 | ||
72 | const struct address_space_operations jffs2_file_address_operations = | |
73 | { | |
74 | .readpage = jffs2_readpage, | |
75 | .write_begin = jffs2_write_begin, | |
76 | .write_end = jffs2_write_end, | |
77 | }; | |
78 | ||
79 | static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg) | |
80 | { | |
81 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); | |
82 | struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); | |
83 | unsigned char *pg_buf; | |
84 | int ret; | |
85 | ||
86 | jffs2_dbg(2, "%s(): ino #%lu, page at offset 0x%lx\n", | |
87 | __func__, inode->i_ino, pg->index << PAGE_SHIFT); | |
88 | ||
89 | BUG_ON(!PageLocked(pg)); | |
90 | ||
91 | pg_buf = kmap(pg); | |
92 | /* FIXME: Can kmap fail? */ | |
93 | ||
94 | ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_SHIFT, | |
95 | PAGE_SIZE); | |
96 | ||
97 | if (ret) { | |
98 | ClearPageUptodate(pg); | |
99 | SetPageError(pg); | |
100 | } else { | |
101 | SetPageUptodate(pg); | |
102 | ClearPageError(pg); | |
103 | } | |
104 | ||
105 | flush_dcache_page(pg); | |
106 | kunmap(pg); | |
107 | ||
108 | jffs2_dbg(2, "readpage finished\n"); | |
109 | return ret; | |
110 | } | |
111 | ||
112 | int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg) | |
113 | { | |
114 | int ret = jffs2_do_readpage_nolock(inode, pg); | |
115 | unlock_page(pg); | |
116 | return ret; | |
117 | } | |
118 | ||
119 | ||
120 | static int jffs2_readpage (struct file *filp, struct page *pg) | |
121 | { | |
122 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host); | |
123 | int ret; | |
124 | ||
125 | mutex_lock(&f->sem); | |
126 | ret = jffs2_do_readpage_unlock(pg->mapping->host, pg); | |
127 | mutex_unlock(&f->sem); | |
128 | return ret; | |
129 | } | |
130 | ||
131 | static int jffs2_write_begin(struct file *filp, struct address_space *mapping, | |
132 | loff_t pos, unsigned len, unsigned flags, | |
133 | struct page **pagep, void **fsdata) | |
134 | { | |
135 | struct page *pg; | |
136 | struct inode *inode = mapping->host; | |
137 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); | |
138 | pgoff_t index = pos >> PAGE_SHIFT; | |
139 | uint32_t pageofs = index << PAGE_SHIFT; | |
140 | int ret = 0; | |
141 | ||
142 | pg = grab_cache_page_write_begin(mapping, index, flags); | |
143 | if (!pg) | |
144 | return -ENOMEM; | |
145 | *pagep = pg; | |
146 | ||
147 | jffs2_dbg(1, "%s()\n", __func__); | |
148 | ||
149 | if (pageofs > inode->i_size) { | |
150 | /* Make new hole frag from old EOF to new page */ | |
151 | struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); | |
152 | struct jffs2_raw_inode ri; | |
153 | struct jffs2_full_dnode *fn; | |
154 | uint32_t alloc_len; | |
155 | ||
156 | jffs2_dbg(1, "Writing new hole frag 0x%x-0x%x between current EOF and new page\n", | |
157 | (unsigned int)inode->i_size, pageofs); | |
158 | ||
159 | ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len, | |
160 | ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); | |
161 | if (ret) | |
162 | goto out_page; | |
163 | ||
164 | mutex_lock(&f->sem); | |
165 | memset(&ri, 0, sizeof(ri)); | |
166 | ||
167 | ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); | |
168 | ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE); | |
169 | ri.totlen = cpu_to_je32(sizeof(ri)); | |
170 | ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4)); | |
171 | ||
172 | ri.ino = cpu_to_je32(f->inocache->ino); | |
173 | ri.version = cpu_to_je32(++f->highest_version); | |
174 | ri.mode = cpu_to_jemode(inode->i_mode); | |
175 | ri.uid = cpu_to_je16(i_uid_read(inode)); | |
176 | ri.gid = cpu_to_je16(i_gid_read(inode)); | |
177 | ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs)); | |
178 | ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds()); | |
179 | ri.offset = cpu_to_je32(inode->i_size); | |
180 | ri.dsize = cpu_to_je32(pageofs - inode->i_size); | |
181 | ri.csize = cpu_to_je32(0); | |
182 | ri.compr = JFFS2_COMPR_ZERO; | |
183 | ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8)); | |
184 | ri.data_crc = cpu_to_je32(0); | |
185 | ||
186 | fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL); | |
187 | ||
188 | if (IS_ERR(fn)) { | |
189 | ret = PTR_ERR(fn); | |
190 | jffs2_complete_reservation(c); | |
191 | mutex_unlock(&f->sem); | |
192 | goto out_page; | |
193 | } | |
194 | ret = jffs2_add_full_dnode_to_inode(c, f, fn); | |
195 | if (f->metadata) { | |
196 | jffs2_mark_node_obsolete(c, f->metadata->raw); | |
197 | jffs2_free_full_dnode(f->metadata); | |
198 | f->metadata = NULL; | |
199 | } | |
200 | if (ret) { | |
201 | jffs2_dbg(1, "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n", | |
202 | ret); | |
203 | jffs2_mark_node_obsolete(c, fn->raw); | |
204 | jffs2_free_full_dnode(fn); | |
205 | jffs2_complete_reservation(c); | |
206 | mutex_unlock(&f->sem); | |
207 | goto out_page; | |
208 | } | |
209 | jffs2_complete_reservation(c); | |
210 | inode->i_size = pageofs; | |
211 | mutex_unlock(&f->sem); | |
212 | } | |
213 | ||
214 | /* | |
215 | * Read in the page if it wasn't already present. Cannot optimize away | |
216 | * the whole page write case until jffs2_write_end can handle the | |
217 | * case of a short-copy. | |
218 | */ | |
219 | if (!PageUptodate(pg)) { | |
220 | mutex_lock(&f->sem); | |
221 | ret = jffs2_do_readpage_nolock(inode, pg); | |
222 | mutex_unlock(&f->sem); | |
223 | if (ret) | |
224 | goto out_page; | |
225 | } | |
226 | jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags); | |
227 | return ret; | |
228 | ||
229 | out_page: | |
230 | unlock_page(pg); | |
231 | put_page(pg); | |
232 | return ret; | |
233 | } | |
234 | ||
235 | static int jffs2_write_end(struct file *filp, struct address_space *mapping, | |
236 | loff_t pos, unsigned len, unsigned copied, | |
237 | struct page *pg, void *fsdata) | |
238 | { | |
239 | /* Actually commit the write from the page cache page we're looking at. | |
240 | * For now, we write the full page out each time. It sucks, but it's simple | |
241 | */ | |
242 | struct inode *inode = mapping->host; | |
243 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); | |
244 | struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); | |
245 | struct jffs2_raw_inode *ri; | |
246 | unsigned start = pos & (PAGE_SIZE - 1); | |
247 | unsigned end = start + copied; | |
248 | unsigned aligned_start = start & ~3; | |
249 | int ret = 0; | |
250 | uint32_t writtenlen = 0; | |
251 | ||
252 | jffs2_dbg(1, "%s(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n", | |
253 | __func__, inode->i_ino, pg->index << PAGE_SHIFT, | |
254 | start, end, pg->flags); | |
255 | ||
256 | /* We need to avoid deadlock with page_cache_read() in | |
257 | jffs2_garbage_collect_pass(). So the page must be | |
258 | up to date to prevent page_cache_read() from trying | |
259 | to re-lock it. */ | |
260 | BUG_ON(!PageUptodate(pg)); | |
261 | ||
262 | if (end == PAGE_SIZE) { | |
263 | /* When writing out the end of a page, write out the | |
264 | _whole_ page. This helps to reduce the number of | |
265 | nodes in files which have many short writes, like | |
266 | syslog files. */ | |
267 | aligned_start = 0; | |
268 | } | |
269 | ||
270 | ri = jffs2_alloc_raw_inode(); | |
271 | ||
272 | if (!ri) { | |
273 | jffs2_dbg(1, "%s(): Allocation of raw inode failed\n", | |
274 | __func__); | |
275 | unlock_page(pg); | |
276 | put_page(pg); | |
277 | return -ENOMEM; | |
278 | } | |
279 | ||
280 | /* Set the fields that the generic jffs2_write_inode_range() code can't find */ | |
281 | ri->ino = cpu_to_je32(inode->i_ino); | |
282 | ri->mode = cpu_to_jemode(inode->i_mode); | |
283 | ri->uid = cpu_to_je16(i_uid_read(inode)); | |
284 | ri->gid = cpu_to_je16(i_gid_read(inode)); | |
285 | ri->isize = cpu_to_je32((uint32_t)inode->i_size); | |
286 | ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds()); | |
287 | ||
288 | /* In 2.4, it was already kmapped by generic_file_write(). Doesn't | |
289 | hurt to do it again. The alternative is ifdefs, which are ugly. */ | |
290 | kmap(pg); | |
291 | ||
292 | ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start, | |
293 | (pg->index << PAGE_SHIFT) + aligned_start, | |
294 | end - aligned_start, &writtenlen); | |
295 | ||
296 | kunmap(pg); | |
297 | ||
298 | if (ret) { | |
299 | /* There was an error writing. */ | |
300 | SetPageError(pg); | |
301 | } | |
302 | ||
303 | /* Adjust writtenlen for the padding we did, so we don't confuse our caller */ | |
304 | writtenlen -= min(writtenlen, (start - aligned_start)); | |
305 | ||
306 | if (writtenlen) { | |
307 | if (inode->i_size < pos + writtenlen) { | |
308 | inode->i_size = pos + writtenlen; | |
309 | inode->i_blocks = (inode->i_size + 511) >> 9; | |
310 | ||
311 | inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime)); | |
312 | } | |
313 | } | |
314 | ||
315 | jffs2_free_raw_inode(ri); | |
316 | ||
317 | if (start+writtenlen < end) { | |
318 | /* generic_file_write has written more to the page cache than we've | |
319 | actually written to the medium. Mark the page !Uptodate so that | |
320 | it gets reread */ | |
321 | jffs2_dbg(1, "%s(): Not all bytes written. Marking page !uptodate\n", | |
322 | __func__); | |
323 | SetPageError(pg); | |
324 | ClearPageUptodate(pg); | |
325 | } | |
326 | ||
327 | jffs2_dbg(1, "%s() returning %d\n", | |
328 | __func__, writtenlen > 0 ? writtenlen : ret); | |
329 | unlock_page(pg); | |
330 | put_page(pg); | |
331 | return writtenlen > 0 ? writtenlen : ret; | |
332 | } |