1 /*
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 *
10 * $Id: file.c,v 1.99 2004/11/16 20:36:11 dwmw2 Exp $
11 *
12 */
13
14 #include <linux/version.h>
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/fs.h>
18 #include <linux/time.h>
19 #include <linux/pagemap.h>
20 #include <linux/highmem.h>
21 #include <linux/crc32.h>
22 #include <linux/jffs2.h>
23 #include "nodelist.h"
24
25 extern int generic_file_open(struct inode *, struct file *) __attribute__((weak));
26 extern loff_t generic_file_llseek(struct file *file, loff_t offset, int origin) __attribute__((weak));
27
28
29 int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync)
30 {
31 struct inode *inode = dentry->d_inode;
32 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
33
34 /* Trigger GC to flush any pending writes for this inode */
35 jffs2_flush_wbuf_gc(c, inode->i_ino);
36
37 return 0;
38 }
39
40 struct file_operations jffs2_file_operations =
41 {
42 .llseek = generic_file_llseek,
43 .open = generic_file_open,
44 .read = generic_file_read,
45 .write = generic_file_write,
46 .ioctl = jffs2_ioctl,
47 .mmap = generic_file_readonly_mmap,
48 .fsync = jffs2_fsync,
49 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,29)
50 .sendfile = generic_file_sendfile
51 #endif
52 };
53
54 /* jffs2_file_inode_operations */
55
56 struct inode_operations jffs2_file_inode_operations =
57 {
58 .setattr = jffs2_setattr
59 };
60
61 struct address_space_operations jffs2_file_address_operations =
62 {
63 .readpage = jffs2_readpage,
64 .prepare_write =jffs2_prepare_write,
65 .commit_write = jffs2_commit_write
66 };
67
68 int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
69 {
70 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
71 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
72 unsigned char *pg_buf;
73 int ret;
74
75 D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT));
76
77 if (!PageLocked(pg))
78 PAGE_BUG(pg);
79
80 pg_buf = kmap(pg);
81 /* FIXME: Can kmap fail? */
82
83 ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
84
85 if (ret) {
86 ClearPageUptodate(pg);
87 SetPageError(pg);
88 } else {
89 SetPageUptodate(pg);
90 ClearPageError(pg);
91 }
92
93 flush_dcache_page(pg);
94 kunmap(pg);
95
96 D2(printk(KERN_DEBUG "readpage finished\n"));
97 return 0;
98 }
99
100 int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg)
101 {
102 int ret = jffs2_do_readpage_nolock(inode, pg);
103 unlock_page(pg);
104 return ret;
105 }
106
107
108 int jffs2_readpage (struct file *filp, struct page *pg)
109 {
110 struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
111 int ret;
112
113 down(&f->sem);
114 ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
115 up(&f->sem);
116 return ret;
117 }
118
119 int jffs2_prepare_write (struct file *filp, struct page *pg, unsigned start, unsigned end)
120 {
121 struct inode *inode = pg->mapping->host;
122 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
123 uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT;
124 int ret = 0;
125
126 D1(printk(KERN_DEBUG "jffs2_prepare_write()\n"));
127
128 if (pageofs > inode->i_size) {
129 /* Make new hole frag from old EOF to new page */
130 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
131 struct jffs2_raw_inode ri;
132 struct jffs2_full_dnode *fn;
133 uint32_t phys_ofs, alloc_len;
134
135 D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
136 (unsigned int)inode->i_size, pageofs));
137
138 ret = jffs2_reserve_space(c, sizeof(ri), &phys_ofs, &alloc_len, ALLOC_NORMAL);
139 if (ret)
140 return ret;
141
142 down(&f->sem);
143 memset(&ri, 0, sizeof(ri));
144
145 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
146 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
147 ri.totlen = cpu_to_je32(sizeof(ri));
148 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
149
150 ri.ino = cpu_to_je32(f->inocache->ino);
151 ri.version = cpu_to_je32(++f->highest_version);
152 ri.mode = cpu_to_jemode(inode->i_mode);
153 ri.uid = cpu_to_je16(inode->i_uid);
154 ri.gid = cpu_to_je16(inode->i_gid);
155 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
156 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
157 ri.offset = cpu_to_je32(inode->i_size);
158 ri.dsize = cpu_to_je32(pageofs - inode->i_size);
159 ri.csize = cpu_to_je32(0);
160 ri.compr = JFFS2_COMPR_ZERO;
161 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
162 ri.data_crc = cpu_to_je32(0);
163
164 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, phys_ofs, ALLOC_NORMAL);
165
166 if (IS_ERR(fn)) {
167 ret = PTR_ERR(fn);
168 jffs2_complete_reservation(c);
169 up(&f->sem);
170 return ret;
171 }
172 ret = jffs2_add_full_dnode_to_inode(c, f, fn);
173 if (f->metadata) {
174 jffs2_mark_node_obsolete(c, f->metadata->raw);
175 jffs2_free_full_dnode(f->metadata);
176 f->metadata = NULL;
177 }
178 if (ret) {
179 D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret));
180 jffs2_mark_node_obsolete(c, fn->raw);
181 jffs2_free_full_dnode(fn);
182 jffs2_complete_reservation(c);
183 up(&f->sem);
184 return ret;
185 }
186 jffs2_complete_reservation(c);
187 inode->i_size = pageofs;
188 up(&f->sem);
189 }
190
191 /* Read in the page if it wasn't already present, unless it's a whole page */
192 if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) {
193 down(&f->sem);
194 ret = jffs2_do_readpage_nolock(inode, pg);
195 up(&f->sem);
196 }
197 D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags));
198 return ret;
199 }
200
201 int jffs2_commit_write (struct file *filp, struct page *pg, 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 }
284
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