0c607c1388f441cb113362b08d345e69ef1927e9
[linux-3.10.git] / fs / jffs2 / file.c
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 static int jffs2_commit_write (struct file *filp, struct page *pg,
29                                unsigned start, unsigned end);
30 static int jffs2_prepare_write (struct file *filp, struct page *pg,
31                                 unsigned start, unsigned end);
32 static int jffs2_readpage (struct file *filp, struct page *pg);
33
34 int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync)
35 {
36         struct inode *inode = dentry->d_inode;
37         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
38
39         /* Trigger GC to flush any pending writes for this inode */
40         jffs2_flush_wbuf_gc(c, inode->i_ino);
41                         
42         return 0;       
43 }
44
45 struct file_operations jffs2_file_operations =
46 {
47         .llseek =       generic_file_llseek,
48         .open =         generic_file_open,
49         .read =         generic_file_read,
50         .write =        generic_file_write,
51         .ioctl =        jffs2_ioctl,
52         .mmap =         generic_file_readonly_mmap,
53         .fsync =        jffs2_fsync,
54 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,29)
55         .sendfile =     generic_file_sendfile
56 #endif
57 };
58
59 /* jffs2_file_inode_operations */
60
61 struct inode_operations jffs2_file_inode_operations =
62 {
63         .setattr =      jffs2_setattr
64 };
65
66 struct address_space_operations jffs2_file_address_operations =
67 {
68         .readpage =     jffs2_readpage,
69         .prepare_write =jffs2_prepare_write,
70         .commit_write = jffs2_commit_write
71 };
72
73 static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
74 {
75         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
76         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
77         unsigned char *pg_buf;
78         int ret;
79
80         D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT));
81
82         if (!PageLocked(pg))
83                 PAGE_BUG(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 0;
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         down(&f->sem);
119         ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
120         up(&f->sem);
121         return ret;
122 }
123
124 static int jffs2_prepare_write (struct file *filp, struct page *pg,
125                                 unsigned start, unsigned end)
126 {
127         struct inode *inode = pg->mapping->host;
128         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
129         uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT;
130         int ret = 0;
131
132         D1(printk(KERN_DEBUG "jffs2_prepare_write()\n"));
133
134         if (pageofs > inode->i_size) {
135                 /* Make new hole frag from old EOF to new page */
136                 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
137                 struct jffs2_raw_inode ri;
138                 struct jffs2_full_dnode *fn;
139                 uint32_t phys_ofs, alloc_len;
140                 
141                 D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
142                           (unsigned int)inode->i_size, pageofs));
143
144                 ret = jffs2_reserve_space(c, sizeof(ri), &phys_ofs, &alloc_len, ALLOC_NORMAL);
145                 if (ret)
146                         return ret;
147
148                 down(&f->sem);
149                 memset(&ri, 0, sizeof(ri));
150
151                 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
152                 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
153                 ri.totlen = cpu_to_je32(sizeof(ri));
154                 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
155
156                 ri.ino = cpu_to_je32(f->inocache->ino);
157                 ri.version = cpu_to_je32(++f->highest_version);
158                 ri.mode = cpu_to_jemode(inode->i_mode);
159                 ri.uid = cpu_to_je16(inode->i_uid);
160                 ri.gid = cpu_to_je16(inode->i_gid);
161                 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
162                 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
163                 ri.offset = cpu_to_je32(inode->i_size);
164                 ri.dsize = cpu_to_je32(pageofs - inode->i_size);
165                 ri.csize = cpu_to_je32(0);
166                 ri.compr = JFFS2_COMPR_ZERO;
167                 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
168                 ri.data_crc = cpu_to_je32(0);
169                 
170                 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, phys_ofs, ALLOC_NORMAL);
171
172                 if (IS_ERR(fn)) {
173                         ret = PTR_ERR(fn);
174                         jffs2_complete_reservation(c);
175                         up(&f->sem);
176                         return ret;
177                 }
178                 ret = jffs2_add_full_dnode_to_inode(c, f, fn);
179                 if (f->metadata) {
180                         jffs2_mark_node_obsolete(c, f->metadata->raw);
181                         jffs2_free_full_dnode(f->metadata);
182                         f->metadata = NULL;
183                 }
184                 if (ret) {
185                         D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret));
186                         jffs2_mark_node_obsolete(c, fn->raw);
187                         jffs2_free_full_dnode(fn);
188                         jffs2_complete_reservation(c);
189                         up(&f->sem);
190                         return ret;
191                 }
192                 jffs2_complete_reservation(c);
193                 inode->i_size = pageofs;
194                 up(&f->sem);
195         }
196         
197         /* Read in the page if it wasn't already present, unless it's a whole page */
198         if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) {
199                 down(&f->sem);
200                 ret = jffs2_do_readpage_nolock(inode, pg);
201                 up(&f->sem);
202         }
203         D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags));
204         return ret;
205 }
206
207 static int jffs2_commit_write (struct file *filp, struct page *pg,
208                                unsigned start, unsigned end)
209 {
210         /* Actually commit the write from the page cache page we're looking at.
211          * For now, we write the full page out each time. It sucks, but it's simple
212          */
213         struct inode *inode = pg->mapping->host;
214         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
215         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
216         struct jffs2_raw_inode *ri;
217         unsigned aligned_start = start & ~3;
218         int ret = 0;
219         uint32_t writtenlen = 0;
220
221         D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
222                   inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags));
223
224         if (!start && end == PAGE_CACHE_SIZE) {
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         }
231
232         ri = jffs2_alloc_raw_inode();
233
234         if (!ri) {
235                 D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n"));
236                 return -ENOMEM;
237         }
238
239         /* Set the fields that the generic jffs2_write_inode_range() code can't find */
240         ri->ino = cpu_to_je32(inode->i_ino);
241         ri->mode = cpu_to_jemode(inode->i_mode);
242         ri->uid = cpu_to_je16(inode->i_uid);
243         ri->gid = cpu_to_je16(inode->i_gid);
244         ri->isize = cpu_to_je32((uint32_t)inode->i_size);
245         ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
246
247         /* In 2.4, it was already kmapped by generic_file_write(). Doesn't
248            hurt to do it again. The alternative is ifdefs, which are ugly. */
249         kmap(pg);
250
251         ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start,
252                                       (pg->index << PAGE_CACHE_SHIFT) + aligned_start,
253                                       end - aligned_start, &writtenlen);
254
255         kunmap(pg);
256
257         if (ret) {
258                 /* There was an error writing. */
259                 SetPageError(pg);
260         }
261         
262         /* Adjust writtenlen for the padding we did, so we don't confuse our caller */
263         if (writtenlen < (start&3))
264                 writtenlen = 0;
265         else
266                 writtenlen -= (start&3);
267
268         if (writtenlen) {
269                 if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) {
270                         inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen;
271                         inode->i_blocks = (inode->i_size + 511) >> 9;
272                         
273                         inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
274                 }
275         }
276
277         jffs2_free_raw_inode(ri);
278
279         if (start+writtenlen < end) {
280                 /* generic_file_write has written more to the page cache than we've
281                    actually written to the medium. Mark the page !Uptodate so that 
282                    it gets reread */
283                 D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n"));
284                 SetPageError(pg);
285                 ClearPageUptodate(pg);
286         }
287
288         D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",writtenlen?writtenlen:ret));
289         return writtenlen?writtenlen:ret;
290 }