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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
David Woodhousec00c3102007-04-25 14:16:47 +01004 * Copyright © 2001-2007 Red Hat, Inc.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
6 * Created by David Woodhouse <dwmw2@infradead.org>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 */
11
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/kernel.h>
13#include <linux/slab.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
Linus Torvalds1da177e2005-04-16 15:20:36 -070022static int jffs2_commit_write (struct file *filp, struct page *pg,
23 unsigned start, unsigned end);
24static int jffs2_prepare_write (struct file *filp, struct page *pg,
25 unsigned start, unsigned end);
26static int jffs2_readpage (struct file *filp, struct page *pg);
27
28int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync)
29{
30 struct inode *inode = dentry->d_inode;
31 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
32
33 /* Trigger GC to flush any pending writes for this inode */
34 jffs2_flush_wbuf_gc(c, inode->i_ino);
Thomas Gleixner182ec4e2005-11-07 11:16:07 +000035
36 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070037}
38
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -080039const struct file_operations jffs2_file_operations =
Linus Torvalds1da177e2005-04-16 15:20:36 -070040{
41 .llseek = generic_file_llseek,
42 .open = generic_file_open,
Badari Pulavarty543ade12006-09-30 23:28:48 -070043 .read = do_sync_read,
44 .aio_read = generic_file_aio_read,
45 .write = do_sync_write,
46 .aio_write = generic_file_aio_write,
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 .ioctl = jffs2_ioctl,
48 .mmap = generic_file_readonly_mmap,
49 .fsync = jffs2_fsync,
Jens Axboe5ffc4ef2007-06-01 11:49:19 +020050 .splice_read = generic_file_splice_read,
Linus Torvalds1da177e2005-04-16 15:20:36 -070051};
52
53/* jffs2_file_inode_operations */
54
Arjan van de Ven92e1d5b2007-02-12 00:55:39 -080055const struct inode_operations jffs2_file_inode_operations =
Linus Torvalds1da177e2005-04-16 15:20:36 -070056{
KaiGai Koheiaa98d7c2006-05-13 15:09:47 +090057 .permission = jffs2_permission,
58 .setattr = jffs2_setattr,
59 .setxattr = jffs2_setxattr,
60 .getxattr = jffs2_getxattr,
61 .listxattr = jffs2_listxattr,
62 .removexattr = jffs2_removexattr
Linus Torvalds1da177e2005-04-16 15:20:36 -070063};
64
Christoph Hellwigf5e54d62006-06-28 04:26:44 -070065const struct address_space_operations jffs2_file_address_operations =
Linus Torvalds1da177e2005-04-16 15:20:36 -070066{
67 .readpage = jffs2_readpage,
68 .prepare_write =jffs2_prepare_write,
69 .commit_write = jffs2_commit_write
70};
71
72static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
73{
74 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
75 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
76 unsigned char *pg_buf;
77 int ret;
78
79 D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT));
80
Matt Mackallcd7619d2005-05-01 08:59:01 -070081 BUG_ON(!PageLocked(pg));
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
83 pg_buf = kmap(pg);
84 /* FIXME: Can kmap fail? */
85
86 ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
87
88 if (ret) {
89 ClearPageUptodate(pg);
90 SetPageError(pg);
91 } else {
92 SetPageUptodate(pg);
93 ClearPageError(pg);
94 }
95
96 flush_dcache_page(pg);
97 kunmap(pg);
98
99 D2(printk(KERN_DEBUG "readpage finished\n"));
100 return 0;
101}
102
103int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg)
104{
105 int ret = jffs2_do_readpage_nolock(inode, pg);
106 unlock_page(pg);
107 return ret;
108}
109
110
111static int jffs2_readpage (struct file *filp, struct page *pg)
112{
113 struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
114 int ret;
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000115
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 down(&f->sem);
117 ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
118 up(&f->sem);
119 return ret;
120}
121
122static int jffs2_prepare_write (struct file *filp, struct page *pg,
123 unsigned start, unsigned end)
124{
125 struct inode *inode = pg->mapping->host;
126 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
127 uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT;
128 int ret = 0;
129
130 D1(printk(KERN_DEBUG "jffs2_prepare_write()\n"));
131
132 if (pageofs > inode->i_size) {
133 /* Make new hole frag from old EOF to new page */
134 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
135 struct jffs2_raw_inode ri;
136 struct jffs2_full_dnode *fn;
David Woodhouse9fe48542006-05-23 00:38:06 +0100137 uint32_t alloc_len;
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000138
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
140 (unsigned int)inode->i_size, pageofs));
141
David Woodhouse9fe48542006-05-23 00:38:06 +0100142 ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
143 ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 if (ret)
145 return ret;
146
147 down(&f->sem);
148 memset(&ri, 0, sizeof(ri));
149
150 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
151 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
152 ri.totlen = cpu_to_je32(sizeof(ri));
153 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
154
155 ri.ino = cpu_to_je32(f->inocache->ino);
156 ri.version = cpu_to_je32(++f->highest_version);
157 ri.mode = cpu_to_jemode(inode->i_mode);
158 ri.uid = cpu_to_je16(inode->i_uid);
159 ri.gid = cpu_to_je16(inode->i_gid);
160 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
161 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
162 ri.offset = cpu_to_je32(inode->i_size);
163 ri.dsize = cpu_to_je32(pageofs - inode->i_size);
164 ri.csize = cpu_to_je32(0);
165 ri.compr = JFFS2_COMPR_ZERO;
166 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
167 ri.data_crc = cpu_to_je32(0);
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000168
David Woodhouse9fe48542006-05-23 00:38:06 +0100169 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
171 if (IS_ERR(fn)) {
172 ret = PTR_ERR(fn);
173 jffs2_complete_reservation(c);
174 up(&f->sem);
175 return ret;
176 }
177 ret = jffs2_add_full_dnode_to_inode(c, f, fn);
178 if (f->metadata) {
179 jffs2_mark_node_obsolete(c, f->metadata->raw);
180 jffs2_free_full_dnode(f->metadata);
181 f->metadata = NULL;
182 }
183 if (ret) {
184 D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret));
185 jffs2_mark_node_obsolete(c, fn->raw);
186 jffs2_free_full_dnode(fn);
187 jffs2_complete_reservation(c);
188 up(&f->sem);
189 return ret;
190 }
191 jffs2_complete_reservation(c);
192 inode->i_size = pageofs;
193 up(&f->sem);
194 }
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000195
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 /* Read in the page if it wasn't already present, unless it's a whole page */
197 if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) {
198 down(&f->sem);
199 ret = jffs2_do_readpage_nolock(inode, pg);
200 up(&f->sem);
201 }
202 D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags));
203 return ret;
204}
205
206static int jffs2_commit_write (struct file *filp, struct page *pg,
207 unsigned start, unsigned end)
208{
209 /* Actually commit the write from the page cache page we're looking at.
210 * For now, we write the full page out each time. It sucks, but it's simple
211 */
212 struct inode *inode = pg->mapping->host;
213 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
214 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
215 struct jffs2_raw_inode *ri;
216 unsigned aligned_start = start & ~3;
217 int ret = 0;
218 uint32_t writtenlen = 0;
219
220 D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
221 inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags));
222
David Woodhousecf5eba52006-05-14 04:06:24 +0100223 if (end == PAGE_CACHE_SIZE) {
224 if (!start) {
225 /* We need to avoid deadlock with page_cache_read() in
226 jffs2_garbage_collect_pass(). So we have to mark the
227 page up to date, to prevent page_cache_read() from
228 trying to re-lock it. */
229 SetPageUptodate(pg);
230 } else {
231 /* When writing out the end of a page, write out the
232 _whole_ page. This helps to reduce the number of
233 nodes in files which have many short writes, like
234 syslog files. */
235 start = aligned_start = 0;
236 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 }
238
239 ri = jffs2_alloc_raw_inode();
240
241 if (!ri) {
242 D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n"));
243 return -ENOMEM;
244 }
245
246 /* Set the fields that the generic jffs2_write_inode_range() code can't find */
247 ri->ino = cpu_to_je32(inode->i_ino);
248 ri->mode = cpu_to_jemode(inode->i_mode);
249 ri->uid = cpu_to_je16(inode->i_uid);
250 ri->gid = cpu_to_je16(inode->i_gid);
251 ri->isize = cpu_to_je32((uint32_t)inode->i_size);
252 ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
253
254 /* In 2.4, it was already kmapped by generic_file_write(). Doesn't
255 hurt to do it again. The alternative is ifdefs, which are ugly. */
256 kmap(pg);
257
258 ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start,
259 (pg->index << PAGE_CACHE_SHIFT) + aligned_start,
260 end - aligned_start, &writtenlen);
261
262 kunmap(pg);
263
264 if (ret) {
265 /* There was an error writing. */
266 SetPageError(pg);
267 }
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000268
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 /* Adjust writtenlen for the padding we did, so we don't confuse our caller */
270 if (writtenlen < (start&3))
271 writtenlen = 0;
272 else
273 writtenlen -= (start&3);
274
275 if (writtenlen) {
276 if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) {
277 inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen;
278 inode->i_blocks = (inode->i_size + 511) >> 9;
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000279
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
281 }
282 }
283
284 jffs2_free_raw_inode(ri);
285
286 if (start+writtenlen < end) {
287 /* generic_file_write has written more to the page cache than we've
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000288 actually written to the medium. Mark the page !Uptodate so that
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 it gets reread */
290 D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n"));
291 SetPageError(pg);
292 ClearPageUptodate(pg);
293 }
294
Todd Poynor4fc67fb2005-10-19 00:29:38 +0100295 D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",start+writtenlen==end?0:ret));
296 return start+writtenlen==end?0:ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297}