Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski...
[linux-2.6-block.git] / fs / jffs2 / file.c
... / ...
CommitLineData
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
24static 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);
27static 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);
30static int jffs2_readpage (struct file *filp, struct page *pg);
31
32int 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 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
50const 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
64const 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 .setxattr = jffs2_setxattr,
70 .getxattr = jffs2_getxattr,
71 .listxattr = jffs2_listxattr,
72 .removexattr = jffs2_removexattr
73};
74
75const struct address_space_operations jffs2_file_address_operations =
76{
77 .readpage = jffs2_readpage,
78 .write_begin = jffs2_write_begin,
79 .write_end = jffs2_write_end,
80};
81
82static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
83{
84 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
85 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
86 unsigned char *pg_buf;
87 int ret;
88
89 jffs2_dbg(2, "%s(): ino #%lu, page at offset 0x%lx\n",
90 __func__, inode->i_ino, pg->index << PAGE_SHIFT);
91
92 BUG_ON(!PageLocked(pg));
93
94 pg_buf = kmap(pg);
95 /* FIXME: Can kmap fail? */
96
97 ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_SHIFT,
98 PAGE_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
115int 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
123static 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
134static 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 pgoff_t index = pos >> PAGE_SHIFT;
142 uint32_t pageofs = index << PAGE_SHIFT;
143 int ret = 0;
144
145 pg = grab_cache_page_write_begin(mapping, index, flags);
146 if (!pg)
147 return -ENOMEM;
148 *pagep = pg;
149
150 jffs2_dbg(1, "%s()\n", __func__);
151
152 if (pageofs > inode->i_size) {
153 /* Make new hole frag from old EOF to new page */
154 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
155 struct jffs2_raw_inode ri;
156 struct jffs2_full_dnode *fn;
157 uint32_t alloc_len;
158
159 jffs2_dbg(1, "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
160 (unsigned int)inode->i_size, pageofs);
161
162 ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
163 ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
164 if (ret)
165 goto out_page;
166
167 mutex_lock(&f->sem);
168 memset(&ri, 0, sizeof(ri));
169
170 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
171 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
172 ri.totlen = cpu_to_je32(sizeof(ri));
173 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
174
175 ri.ino = cpu_to_je32(f->inocache->ino);
176 ri.version = cpu_to_je32(++f->highest_version);
177 ri.mode = cpu_to_jemode(inode->i_mode);
178 ri.uid = cpu_to_je16(i_uid_read(inode));
179 ri.gid = cpu_to_je16(i_gid_read(inode));
180 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
181 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
182 ri.offset = cpu_to_je32(inode->i_size);
183 ri.dsize = cpu_to_je32(pageofs - inode->i_size);
184 ri.csize = cpu_to_je32(0);
185 ri.compr = JFFS2_COMPR_ZERO;
186 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
187 ri.data_crc = cpu_to_je32(0);
188
189 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL);
190
191 if (IS_ERR(fn)) {
192 ret = PTR_ERR(fn);
193 jffs2_complete_reservation(c);
194 mutex_unlock(&f->sem);
195 goto out_page;
196 }
197 ret = jffs2_add_full_dnode_to_inode(c, f, fn);
198 if (f->metadata) {
199 jffs2_mark_node_obsolete(c, f->metadata->raw);
200 jffs2_free_full_dnode(f->metadata);
201 f->metadata = NULL;
202 }
203 if (ret) {
204 jffs2_dbg(1, "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n",
205 ret);
206 jffs2_mark_node_obsolete(c, fn->raw);
207 jffs2_free_full_dnode(fn);
208 jffs2_complete_reservation(c);
209 mutex_unlock(&f->sem);
210 goto out_page;
211 }
212 jffs2_complete_reservation(c);
213 inode->i_size = pageofs;
214 mutex_unlock(&f->sem);
215 }
216
217 /*
218 * Read in the page if it wasn't already present. Cannot optimize away
219 * the whole page write case until jffs2_write_end can handle the
220 * case of a short-copy.
221 */
222 if (!PageUptodate(pg)) {
223 mutex_lock(&f->sem);
224 ret = jffs2_do_readpage_nolock(inode, pg);
225 mutex_unlock(&f->sem);
226 if (ret)
227 goto out_page;
228 }
229 jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags);
230 return ret;
231
232out_page:
233 unlock_page(pg);
234 put_page(pg);
235 return ret;
236}
237
238static int jffs2_write_end(struct file *filp, struct address_space *mapping,
239 loff_t pos, unsigned len, unsigned copied,
240 struct page *pg, void *fsdata)
241{
242 /* Actually commit the write from the page cache page we're looking at.
243 * For now, we write the full page out each time. It sucks, but it's simple
244 */
245 struct inode *inode = mapping->host;
246 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
247 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
248 struct jffs2_raw_inode *ri;
249 unsigned start = pos & (PAGE_SIZE - 1);
250 unsigned end = start + copied;
251 unsigned aligned_start = start & ~3;
252 int ret = 0;
253 uint32_t writtenlen = 0;
254
255 jffs2_dbg(1, "%s(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
256 __func__, inode->i_ino, pg->index << PAGE_SHIFT,
257 start, end, pg->flags);
258
259 /* We need to avoid deadlock with page_cache_read() in
260 jffs2_garbage_collect_pass(). So the page must be
261 up to date to prevent page_cache_read() from trying
262 to re-lock it. */
263 BUG_ON(!PageUptodate(pg));
264
265 if (end == PAGE_SIZE) {
266 /* When writing out the end of a page, write out the
267 _whole_ page. This helps to reduce the number of
268 nodes in files which have many short writes, like
269 syslog files. */
270 aligned_start = 0;
271 }
272
273 ri = jffs2_alloc_raw_inode();
274
275 if (!ri) {
276 jffs2_dbg(1, "%s(): Allocation of raw inode failed\n",
277 __func__);
278 unlock_page(pg);
279 put_page(pg);
280 return -ENOMEM;
281 }
282
283 /* Set the fields that the generic jffs2_write_inode_range() code can't find */
284 ri->ino = cpu_to_je32(inode->i_ino);
285 ri->mode = cpu_to_jemode(inode->i_mode);
286 ri->uid = cpu_to_je16(i_uid_read(inode));
287 ri->gid = cpu_to_je16(i_gid_read(inode));
288 ri->isize = cpu_to_je32((uint32_t)inode->i_size);
289 ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
290
291 /* In 2.4, it was already kmapped by generic_file_write(). Doesn't
292 hurt to do it again. The alternative is ifdefs, which are ugly. */
293 kmap(pg);
294
295 ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start,
296 (pg->index << PAGE_SHIFT) + aligned_start,
297 end - aligned_start, &writtenlen);
298
299 kunmap(pg);
300
301 if (ret) {
302 /* There was an error writing. */
303 SetPageError(pg);
304 }
305
306 /* Adjust writtenlen for the padding we did, so we don't confuse our caller */
307 writtenlen -= min(writtenlen, (start - aligned_start));
308
309 if (writtenlen) {
310 if (inode->i_size < pos + writtenlen) {
311 inode->i_size = pos + writtenlen;
312 inode->i_blocks = (inode->i_size + 511) >> 9;
313
314 inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
315 }
316 }
317
318 jffs2_free_raw_inode(ri);
319
320 if (start+writtenlen < end) {
321 /* generic_file_write has written more to the page cache than we've
322 actually written to the medium. Mark the page !Uptodate so that
323 it gets reread */
324 jffs2_dbg(1, "%s(): Not all bytes written. Marking page !uptodate\n",
325 __func__);
326 SetPageError(pg);
327 ClearPageUptodate(pg);
328 }
329
330 jffs2_dbg(1, "%s() returning %d\n",
331 __func__, writtenlen > 0 ? writtenlen : ret);
332 unlock_page(pg);
333 put_page(pg);
334 return writtenlen > 0 ? writtenlen : ret;
335}