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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright (C) 2001-2003 Red Hat, Inc.
5 *
6 * Created by David Woodhouse <dwmw2@infradead.org>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
David Woodhouse265489f2005-07-06 13:13:13 +010010 * $Id: file.c,v 1.102 2005/07/06 12:13:09 dwmw2 Exp $
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 *
12 */
13
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/kernel.h>
15#include <linux/slab.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
Linus Torvalds1da177e2005-04-16 15:20:36 -070024static int jffs2_commit_write (struct file *filp, struct page *pg,
25 unsigned start, unsigned end);
26static int jffs2_prepare_write (struct file *filp, struct page *pg,
27 unsigned start, unsigned end);
28static int jffs2_readpage (struct file *filp, struct page *pg);
29
30int 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
41struct file_operations jffs2_file_operations =
42{
43 .llseek = generic_file_llseek,
44 .open = generic_file_open,
45 .read = generic_file_read,
46 .write = generic_file_write,
47 .ioctl = jffs2_ioctl,
48 .mmap = generic_file_readonly_mmap,
49 .fsync = jffs2_fsync,
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 .sendfile = generic_file_sendfile
Linus Torvalds1da177e2005-04-16 15:20:36 -070051};
52
53/* jffs2_file_inode_operations */
54
55struct inode_operations jffs2_file_inode_operations =
56{
57 .setattr = jffs2_setattr
58};
59
60struct address_space_operations jffs2_file_address_operations =
61{
62 .readpage = jffs2_readpage,
63 .prepare_write =jffs2_prepare_write,
64 .commit_write = jffs2_commit_write
65};
66
67static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
68{
69 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
70 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
71 unsigned char *pg_buf;
72 int ret;
73
74 D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT));
75
Matt Mackallcd7619d2005-05-01 08:59:01 -070076 BUG_ON(!PageLocked(pg));
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
78 pg_buf = kmap(pg);
79 /* FIXME: Can kmap fail? */
80
81 ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
82
83 if (ret) {
84 ClearPageUptodate(pg);
85 SetPageError(pg);
86 } else {
87 SetPageUptodate(pg);
88 ClearPageError(pg);
89 }
90
91 flush_dcache_page(pg);
92 kunmap(pg);
93
94 D2(printk(KERN_DEBUG "readpage finished\n"));
95 return 0;
96}
97
98int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg)
99{
100 int ret = jffs2_do_readpage_nolock(inode, pg);
101 unlock_page(pg);
102 return ret;
103}
104
105
106static int jffs2_readpage (struct file *filp, struct page *pg)
107{
108 struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
109 int ret;
110
111 down(&f->sem);
112 ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
113 up(&f->sem);
114 return ret;
115}
116
117static int jffs2_prepare_write (struct file *filp, struct page *pg,
118 unsigned start, unsigned end)
119{
120 struct inode *inode = pg->mapping->host;
121 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
122 uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT;
123 int ret = 0;
124
125 D1(printk(KERN_DEBUG "jffs2_prepare_write()\n"));
126
127 if (pageofs > inode->i_size) {
128 /* Make new hole frag from old EOF to new page */
129 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
130 struct jffs2_raw_inode ri;
131 struct jffs2_full_dnode *fn;
132 uint32_t phys_ofs, alloc_len;
133
134 D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
135 (unsigned int)inode->i_size, pageofs));
136
137 ret = jffs2_reserve_space(c, sizeof(ri), &phys_ofs, &alloc_len, ALLOC_NORMAL);
138 if (ret)
139 return ret;
140
141 down(&f->sem);
142 memset(&ri, 0, sizeof(ri));
143
144 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
145 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
146 ri.totlen = cpu_to_je32(sizeof(ri));
147 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
148
149 ri.ino = cpu_to_je32(f->inocache->ino);
150 ri.version = cpu_to_je32(++f->highest_version);
151 ri.mode = cpu_to_jemode(inode->i_mode);
152 ri.uid = cpu_to_je16(inode->i_uid);
153 ri.gid = cpu_to_je16(inode->i_gid);
154 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
155 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
156 ri.offset = cpu_to_je32(inode->i_size);
157 ri.dsize = cpu_to_je32(pageofs - inode->i_size);
158 ri.csize = cpu_to_je32(0);
159 ri.compr = JFFS2_COMPR_ZERO;
160 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
161 ri.data_crc = cpu_to_je32(0);
162
163 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, phys_ofs, ALLOC_NORMAL);
164
165 if (IS_ERR(fn)) {
166 ret = PTR_ERR(fn);
167 jffs2_complete_reservation(c);
168 up(&f->sem);
169 return ret;
170 }
171 ret = jffs2_add_full_dnode_to_inode(c, f, fn);
172 if (f->metadata) {
173 jffs2_mark_node_obsolete(c, f->metadata->raw);
174 jffs2_free_full_dnode(f->metadata);
175 f->metadata = NULL;
176 }
177 if (ret) {
178 D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret));
179 jffs2_mark_node_obsolete(c, fn->raw);
180 jffs2_free_full_dnode(fn);
181 jffs2_complete_reservation(c);
182 up(&f->sem);
183 return ret;
184 }
185 jffs2_complete_reservation(c);
186 inode->i_size = pageofs;
187 up(&f->sem);
188 }
189
190 /* Read in the page if it wasn't already present, unless it's a whole page */
191 if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) {
192 down(&f->sem);
193 ret = jffs2_do_readpage_nolock(inode, pg);
194 up(&f->sem);
195 }
196 D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags));
197 return ret;
198}
199
200static int jffs2_commit_write (struct file *filp, struct page *pg,
201 unsigned start, unsigned end)
202{
203 /* Actually commit the write from the page cache page we're looking at.
204 * For now, we write the full page out each time. It sucks, but it's simple
205 */
206 struct inode *inode = pg->mapping->host;
207 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
208 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
209 struct jffs2_raw_inode *ri;
210 unsigned aligned_start = start & ~3;
211 int ret = 0;
212 uint32_t writtenlen = 0;
213
214 D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
215 inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags));
216
217 if (!start && end == PAGE_CACHE_SIZE) {
218 /* We need to avoid deadlock with page_cache_read() in
219 jffs2_garbage_collect_pass(). So we have to mark the
220 page up to date, to prevent page_cache_read() from
221 trying to re-lock it. */
222 SetPageUptodate(pg);
223 }
224
225 ri = jffs2_alloc_raw_inode();
226
227 if (!ri) {
228 D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n"));
229 return -ENOMEM;
230 }
231
232 /* Set the fields that the generic jffs2_write_inode_range() code can't find */
233 ri->ino = cpu_to_je32(inode->i_ino);
234 ri->mode = cpu_to_jemode(inode->i_mode);
235 ri->uid = cpu_to_je16(inode->i_uid);
236 ri->gid = cpu_to_je16(inode->i_gid);
237 ri->isize = cpu_to_je32((uint32_t)inode->i_size);
238 ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
239
240 /* In 2.4, it was already kmapped by generic_file_write(). Doesn't
241 hurt to do it again. The alternative is ifdefs, which are ugly. */
242 kmap(pg);
243
244 ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start,
245 (pg->index << PAGE_CACHE_SHIFT) + aligned_start,
246 end - aligned_start, &writtenlen);
247
248 kunmap(pg);
249
250 if (ret) {
251 /* There was an error writing. */
252 SetPageError(pg);
253 }
254
255 /* Adjust writtenlen for the padding we did, so we don't confuse our caller */
256 if (writtenlen < (start&3))
257 writtenlen = 0;
258 else
259 writtenlen -= (start&3);
260
261 if (writtenlen) {
262 if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) {
263 inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen;
264 inode->i_blocks = (inode->i_size + 511) >> 9;
265
266 inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
267 }
268 }
269
270 jffs2_free_raw_inode(ri);
271
272 if (start+writtenlen < end) {
273 /* generic_file_write has written more to the page cache than we've
274 actually written to the medium. Mark the page !Uptodate so that
275 it gets reread */
276 D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n"));
277 SetPageError(pg);
278 ClearPageUptodate(pg);
279 }
280
281 D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",writtenlen?writtenlen:ret));
282 return writtenlen?writtenlen:ret;
283}