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, |
29 | struct page **pagep, void **fsdata); |
30 | static int jffs2_read_folio(struct file *filp, struct folio *folio); |
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(file: 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, ino: 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 = filemap_splice_read, |
60 | .splice_write = iter_file_splice_write, |
61 | }; |
62 | |
63 | /* jffs2_file_inode_operations */ |
64 | |
65 | const struct inode_operations jffs2_file_inode_operations = |
66 | { |
67 | .get_inode_acl = jffs2_get_acl, |
68 | .set_acl = jffs2_set_acl, |
69 | .setattr = jffs2_setattr, |
70 | .listxattr = jffs2_listxattr, |
71 | }; |
72 | |
73 | const struct address_space_operations jffs2_file_address_operations = |
74 | { |
75 | .read_folio = jffs2_read_folio, |
76 | .write_begin = jffs2_write_begin, |
77 | .write_end = jffs2_write_end, |
78 | }; |
79 | |
80 | static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg) |
81 | { |
82 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); |
83 | struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); |
84 | unsigned char *pg_buf; |
85 | int ret; |
86 | |
87 | jffs2_dbg(2, "%s(): ino #%lu, page at offset 0x%lx\n" , |
88 | __func__, inode->i_ino, pg->index << PAGE_SHIFT); |
89 | |
90 | BUG_ON(!PageLocked(pg)); |
91 | |
92 | pg_buf = kmap(page: pg); |
93 | /* FIXME: Can kmap fail? */ |
94 | |
95 | ret = jffs2_read_inode_range(c, f, buf: pg_buf, offset: pg->index << PAGE_SHIFT, |
96 | PAGE_SIZE); |
97 | |
98 | if (ret) { |
99 | ClearPageUptodate(page: pg); |
100 | SetPageError(pg); |
101 | } else { |
102 | SetPageUptodate(pg); |
103 | ClearPageError(page: pg); |
104 | } |
105 | |
106 | flush_dcache_page(page: pg); |
107 | kunmap(page: pg); |
108 | |
109 | jffs2_dbg(2, "readpage finished\n" ); |
110 | return ret; |
111 | } |
112 | |
113 | int __jffs2_read_folio(struct file *file, struct folio *folio) |
114 | { |
115 | int ret = jffs2_do_readpage_nolock(inode: folio->mapping->host, pg: &folio->page); |
116 | folio_unlock(folio); |
117 | return ret; |
118 | } |
119 | |
120 | static int jffs2_read_folio(struct file *file, struct folio *folio) |
121 | { |
122 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(folio->mapping->host); |
123 | int ret; |
124 | |
125 | mutex_lock(&f->sem); |
126 | ret = __jffs2_read_folio(file, folio); |
127 | mutex_unlock(lock: &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, |
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 | struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); |
139 | pgoff_t index = pos >> PAGE_SHIFT; |
140 | int ret = 0; |
141 | |
142 | jffs2_dbg(1, "%s()\n" , __func__); |
143 | |
144 | if (pos > inode->i_size) { |
145 | /* Make new hole frag from old EOF to new position */ |
146 | struct jffs2_raw_inode ri; |
147 | struct jffs2_full_dnode *fn; |
148 | uint32_t alloc_len; |
149 | |
150 | jffs2_dbg(1, "Writing new hole frag 0x%x-0x%x between current EOF and new position\n" , |
151 | (unsigned int)inode->i_size, (uint32_t)pos); |
152 | |
153 | ret = jffs2_reserve_space(c, minsize: sizeof(ri), len: &alloc_len, |
154 | ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); |
155 | if (ret) |
156 | goto out_err; |
157 | |
158 | mutex_lock(&f->sem); |
159 | memset(&ri, 0, sizeof(ri)); |
160 | |
161 | ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); |
162 | ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE); |
163 | ri.totlen = cpu_to_je32(sizeof(ri)); |
164 | ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4)); |
165 | |
166 | ri.ino = cpu_to_je32(f->inocache->ino); |
167 | ri.version = cpu_to_je32(++f->highest_version); |
168 | ri.mode = cpu_to_jemode(inode->i_mode); |
169 | ri.uid = cpu_to_je16(i_uid_read(inode)); |
170 | ri.gid = cpu_to_je16(i_gid_read(inode)); |
171 | ri.isize = cpu_to_je32((uint32_t)pos); |
172 | ri.atime = ri.ctime = ri.mtime = cpu_to_je32(JFFS2_NOW()); |
173 | ri.offset = cpu_to_je32(inode->i_size); |
174 | ri.dsize = cpu_to_je32((uint32_t)pos - inode->i_size); |
175 | ri.csize = cpu_to_je32(0); |
176 | ri.compr = JFFS2_COMPR_ZERO; |
177 | ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8)); |
178 | ri.data_crc = cpu_to_je32(0); |
179 | |
180 | fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL); |
181 | |
182 | if (IS_ERR(fn)) { |
183 | ret = PTR_ERR(fn); |
184 | jffs2_complete_reservation(c); |
185 | mutex_unlock(&f->sem); |
186 | goto out_err; |
187 | } |
188 | ret = jffs2_add_full_dnode_to_inode(c, f, fn); |
189 | if (f->metadata) { |
190 | jffs2_mark_node_obsolete(c, f->metadata->raw); |
191 | jffs2_free_full_dnode(f->metadata); |
192 | f->metadata = NULL; |
193 | } |
194 | if (ret) { |
195 | jffs2_dbg(1, "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n" , |
196 | ret); |
197 | jffs2_mark_node_obsolete(c, fn->raw); |
198 | jffs2_free_full_dnode(fn); |
199 | jffs2_complete_reservation(c); |
200 | mutex_unlock(&f->sem); |
201 | goto out_err; |
202 | } |
203 | jffs2_complete_reservation(c); |
204 | inode->i_size = pos; |
205 | mutex_unlock(&f->sem); |
206 | } |
207 | |
208 | /* |
209 | * While getting a page and reading data in, lock c->alloc_sem until |
210 | * the page is Uptodate. Otherwise GC task may attempt to read the same |
211 | * page in read_cache_page(), which causes a deadlock. |
212 | */ |
213 | mutex_lock(&c->alloc_sem); |
214 | pg = grab_cache_page_write_begin(mapping, index); |
215 | if (!pg) { |
216 | ret = -ENOMEM; |
217 | goto release_sem; |
218 | } |
219 | *pagep = pg; |
220 | |
221 | /* |
222 | * Read in the page if it wasn't already present. Cannot optimize away |
223 | * the whole page write case until jffs2_write_end can handle the |
224 | * case of a short-copy. |
225 | */ |
226 | if (!PageUptodate(pg)) { |
227 | mutex_lock(&f->sem); |
228 | ret = jffs2_do_readpage_nolock(inode, pg); |
229 | mutex_unlock(&f->sem); |
230 | if (ret) { |
231 | unlock_page(pg); |
232 | put_page(pg); |
233 | goto release_sem; |
234 | } |
235 | } |
236 | jffs2_dbg(1, "end write_begin(). pg->flags %lx\n" , pg->flags); |
237 | |
238 | release_sem: |
239 | mutex_unlock(&c->alloc_sem); |
240 | out_err: |
241 | return ret; |
242 | } |
243 | |
244 | static int jffs2_write_end(struct file *filp, struct address_space *mapping, |
245 | loff_t pos, unsigned len, unsigned copied, |
246 | struct page *pg, void *fsdata) |
247 | { |
248 | /* Actually commit the write from the page cache page we're looking at. |
249 | * For now, we write the full page out each time. It sucks, but it's simple |
250 | */ |
251 | struct inode *inode = mapping->host; |
252 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); |
253 | struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); |
254 | struct jffs2_raw_inode *ri; |
255 | unsigned start = pos & (PAGE_SIZE - 1); |
256 | unsigned end = start + copied; |
257 | unsigned aligned_start = start & ~3; |
258 | int ret = 0; |
259 | uint32_t writtenlen = 0; |
260 | |
261 | jffs2_dbg(1, "%s(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n" , |
262 | __func__, inode->i_ino, pg->index << PAGE_SHIFT, |
263 | start, end, pg->flags); |
264 | |
265 | /* We need to avoid deadlock with page_cache_read() in |
266 | jffs2_garbage_collect_pass(). So the page must be |
267 | up to date to prevent page_cache_read() from trying |
268 | to re-lock it. */ |
269 | BUG_ON(!PageUptodate(pg)); |
270 | |
271 | if (end == PAGE_SIZE) { |
272 | /* When writing out the end of a page, write out the |
273 | _whole_ page. This helps to reduce the number of |
274 | nodes in files which have many short writes, like |
275 | syslog files. */ |
276 | aligned_start = 0; |
277 | } |
278 | |
279 | ri = jffs2_alloc_raw_inode(); |
280 | |
281 | if (!ri) { |
282 | jffs2_dbg(1, "%s(): Allocation of raw inode failed\n" , |
283 | __func__); |
284 | unlock_page(page: pg); |
285 | put_page(page: pg); |
286 | return -ENOMEM; |
287 | } |
288 | |
289 | /* Set the fields that the generic jffs2_write_inode_range() code can't find */ |
290 | ri->ino = cpu_to_je32(inode->i_ino); |
291 | ri->mode = cpu_to_jemode(inode->i_mode); |
292 | ri->uid = cpu_to_je16(i_uid_read(inode)); |
293 | ri->gid = cpu_to_je16(i_gid_read(inode)); |
294 | ri->isize = cpu_to_je32((uint32_t)inode->i_size); |
295 | ri->atime = ri->ctime = ri->mtime = cpu_to_je32(JFFS2_NOW()); |
296 | |
297 | /* In 2.4, it was already kmapped by generic_file_write(). Doesn't |
298 | hurt to do it again. The alternative is ifdefs, which are ugly. */ |
299 | kmap(page: pg); |
300 | |
301 | ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start, |
302 | offset: (pg->index << PAGE_SHIFT) + aligned_start, |
303 | writelen: end - aligned_start, retlen: &writtenlen); |
304 | |
305 | kunmap(page: pg); |
306 | |
307 | if (ret) { |
308 | /* There was an error writing. */ |
309 | SetPageError(pg); |
310 | } |
311 | |
312 | /* Adjust writtenlen for the padding we did, so we don't confuse our caller */ |
313 | writtenlen -= min(writtenlen, (start - aligned_start)); |
314 | |
315 | if (writtenlen) { |
316 | if (inode->i_size < pos + writtenlen) { |
317 | inode->i_size = pos + writtenlen; |
318 | inode->i_blocks = (inode->i_size + 511) >> 9; |
319 | |
320 | inode_set_mtime_to_ts(inode, |
321 | ts: inode_set_ctime_to_ts(inode, ITIME(je32_to_cpu(ri->ctime)))); |
322 | } |
323 | } |
324 | |
325 | jffs2_free_raw_inode(ri); |
326 | |
327 | if (start+writtenlen < end) { |
328 | /* generic_file_write has written more to the page cache than we've |
329 | actually written to the medium. Mark the page !Uptodate so that |
330 | it gets reread */ |
331 | jffs2_dbg(1, "%s(): Not all bytes written. Marking page !uptodate\n" , |
332 | __func__); |
333 | SetPageError(pg); |
334 | ClearPageUptodate(page: pg); |
335 | } |
336 | |
337 | jffs2_dbg(1, "%s() returning %d\n" , |
338 | __func__, writtenlen > 0 ? writtenlen : ret); |
339 | unlock_page(page: pg); |
340 | put_page(page: pg); |
341 | return writtenlen > 0 ? writtenlen : ret; |
342 | } |
343 | |