jffs2: Update copyright notices
[linux-3.10.git] / fs / jffs2 / file.c
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 #include <linux/kernel.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         .unlocked_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         .check_acl =    jffs2_check_acl,
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 ret;
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         mutex_lock(&f->sem);
119         ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
120         mutex_unlock(&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_write_begin(mapping, index, flags);
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                 mutex_lock(&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                         mutex_unlock(&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                         mutex_unlock(&f->sem);
199                         goto out_page;
200                 }
201                 jffs2_complete_reservation(c);
202                 inode->i_size = pageofs;
203                 mutex_unlock(&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                 mutex_lock(&f->sem);
213                 ret = jffs2_do_readpage_nolock(inode, pg);
214                 mutex_unlock(&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 }