Merge ../linux-2.6/
[linux-2.6] / 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 1.102 2005/07/06 12:13:09 dwmw2 Exp $
11  *
12  */
13
14 #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
24 extern int generic_file_open(struct inode *, struct file *) __attribute__((weak));
25 extern loff_t generic_file_llseek(struct file *file, loff_t offset, int origin) __attribute__((weak));
26
27 static int jffs2_commit_write (struct file *filp, struct page *pg,
28                                unsigned start, unsigned end);
29 static int jffs2_prepare_write (struct file *filp, struct page *pg,
30                                 unsigned start, unsigned end);
31 static int jffs2_readpage (struct file *filp, struct page *pg);
32
33 int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync)
34 {
35         struct inode *inode = dentry->d_inode;
36         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
37
38         /* Trigger GC to flush any pending writes for this inode */
39         jffs2_flush_wbuf_gc(c, inode->i_ino);
40                         
41         return 0;       
42 }
43
44 struct file_operations jffs2_file_operations =
45 {
46         .llseek =       generic_file_llseek,
47         .open =         generic_file_open,
48         .read =         generic_file_read,
49         .write =        generic_file_write,
50         .ioctl =        jffs2_ioctl,
51         .mmap =         generic_file_readonly_mmap,
52         .fsync =        jffs2_fsync,
53         .sendfile =     generic_file_sendfile
54 };
55
56 /* jffs2_file_inode_operations */
57
58 struct inode_operations jffs2_file_inode_operations =
59 {
60         .setattr =      jffs2_setattr
61 };
62
63 struct address_space_operations jffs2_file_address_operations =
64 {
65         .readpage =     jffs2_readpage,
66         .prepare_write =jffs2_prepare_write,
67         .commit_write = jffs2_commit_write
68 };
69
70 static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
71 {
72         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
73         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
74         unsigned char *pg_buf;
75         int ret;
76
77         D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT));
78
79         BUG_ON(!PageLocked(pg));
80
81         pg_buf = kmap(pg);
82         /* FIXME: Can kmap fail? */
83
84         ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
85
86         if (ret) {
87                 ClearPageUptodate(pg);
88                 SetPageError(pg);
89         } else {
90                 SetPageUptodate(pg);
91                 ClearPageError(pg);
92         }
93
94         flush_dcache_page(pg);
95         kunmap(pg);
96
97         D2(printk(KERN_DEBUG "readpage finished\n"));
98         return 0;
99 }
100
101 int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg)
102 {
103         int ret = jffs2_do_readpage_nolock(inode, pg);
104         unlock_page(pg);
105         return ret;
106 }
107
108
109 static int jffs2_readpage (struct file *filp, struct page *pg)
110 {
111         struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
112         int ret;
113         
114         down(&f->sem);
115         ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
116         up(&f->sem);
117         return ret;
118 }
119
120 static int jffs2_prepare_write (struct file *filp, struct page *pg,
121                                 unsigned start, unsigned end)
122 {
123         struct inode *inode = pg->mapping->host;
124         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
125         uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT;
126         int ret = 0;
127
128         D1(printk(KERN_DEBUG "jffs2_prepare_write()\n"));
129
130         if (pageofs > inode->i_size) {
131                 /* Make new hole frag from old EOF to new page */
132                 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
133                 struct jffs2_raw_inode ri;
134                 struct jffs2_full_dnode *fn;
135                 uint32_t phys_ofs, alloc_len;
136                 
137                 D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
138                           (unsigned int)inode->i_size, pageofs));
139
140                 ret = jffs2_reserve_space(c, sizeof(ri), &phys_ofs, &alloc_len, ALLOC_NORMAL);
141                 if (ret)
142                         return ret;
143
144                 down(&f->sem);
145                 memset(&ri, 0, sizeof(ri));
146
147                 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
148                 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
149                 ri.totlen = cpu_to_je32(sizeof(ri));
150                 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
151
152                 ri.ino = cpu_to_je32(f->inocache->ino);
153                 ri.version = cpu_to_je32(++f->highest_version);
154                 ri.mode = cpu_to_jemode(inode->i_mode);
155                 ri.uid = cpu_to_je16(inode->i_uid);
156                 ri.gid = cpu_to_je16(inode->i_gid);
157                 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
158                 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
159                 ri.offset = cpu_to_je32(inode->i_size);
160                 ri.dsize = cpu_to_je32(pageofs - inode->i_size);
161                 ri.csize = cpu_to_je32(0);
162                 ri.compr = JFFS2_COMPR_ZERO;
163                 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
164                 ri.data_crc = cpu_to_je32(0);
165                 
166                 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, phys_ofs, ALLOC_NORMAL);
167
168                 if (IS_ERR(fn)) {
169                         ret = PTR_ERR(fn);
170                         jffs2_complete_reservation(c);
171                         up(&f->sem);
172                         return ret;
173                 }
174                 ret = jffs2_add_full_dnode_to_inode(c, f, fn);
175                 if (f->metadata) {
176                         jffs2_mark_node_obsolete(c, f->metadata->raw);
177                         jffs2_free_full_dnode(f->metadata);
178                         f->metadata = NULL;
179                 }
180                 if (ret) {
181                         D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret));
182                         jffs2_mark_node_obsolete(c, fn->raw);
183                         jffs2_free_full_dnode(fn);
184                         jffs2_complete_reservation(c);
185                         up(&f->sem);
186                         return ret;
187                 }
188                 jffs2_complete_reservation(c);
189                 inode->i_size = pageofs;
190                 up(&f->sem);
191         }
192         
193         /* Read in the page if it wasn't already present, unless it's a whole page */
194         if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) {
195                 down(&f->sem);
196                 ret = jffs2_do_readpage_nolock(inode, pg);
197                 up(&f->sem);
198         }
199         D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags));
200         return ret;
201 }
202
203 static int jffs2_commit_write (struct file *filp, struct page *pg,
204                                unsigned start, unsigned end)
205 {
206         /* Actually commit the write from the page cache page we're looking at.
207          * For now, we write the full page out each time. It sucks, but it's simple
208          */
209         struct inode *inode = pg->mapping->host;
210         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
211         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
212         struct jffs2_raw_inode *ri;
213         unsigned aligned_start = start & ~3;
214         int ret = 0;
215         uint32_t writtenlen = 0;
216
217         D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
218                   inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags));
219
220         if (!start && end == PAGE_CACHE_SIZE) {
221                 /* We need to avoid deadlock with page_cache_read() in
222                    jffs2_garbage_collect_pass(). So we have to mark the
223                    page up to date, to prevent page_cache_read() from 
224                    trying to re-lock it. */
225                 SetPageUptodate(pg);
226         }
227
228         ri = jffs2_alloc_raw_inode();
229
230         if (!ri) {
231                 D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n"));
232                 return -ENOMEM;
233         }
234
235         /* Set the fields that the generic jffs2_write_inode_range() code can't find */
236         ri->ino = cpu_to_je32(inode->i_ino);
237         ri->mode = cpu_to_jemode(inode->i_mode);
238         ri->uid = cpu_to_je16(inode->i_uid);
239         ri->gid = cpu_to_je16(inode->i_gid);
240         ri->isize = cpu_to_je32((uint32_t)inode->i_size);
241         ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
242
243         /* In 2.4, it was already kmapped by generic_file_write(). Doesn't
244            hurt to do it again. The alternative is ifdefs, which are ugly. */
245         kmap(pg);
246
247         ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start,
248                                       (pg->index << PAGE_CACHE_SHIFT) + aligned_start,
249                                       end - aligned_start, &writtenlen);
250
251         kunmap(pg);
252
253         if (ret) {
254                 /* There was an error writing. */
255                 SetPageError(pg);
256         }
257         
258         /* Adjust writtenlen for the padding we did, so we don't confuse our caller */
259         if (writtenlen < (start&3))
260                 writtenlen = 0;
261         else
262                 writtenlen -= (start&3);
263
264         if (writtenlen) {
265                 if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) {
266                         inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen;
267                         inode->i_blocks = (inode->i_size + 511) >> 9;
268                         
269                         inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
270                 }
271         }
272
273         jffs2_free_raw_inode(ri);
274
275         if (start+writtenlen < end) {
276                 /* generic_file_write has written more to the page cache than we've
277                    actually written to the medium. Mark the page !Uptodate so that 
278                    it gets reread */
279                 D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n"));
280                 SetPageError(pg);
281                 ClearPageUptodate(pg);
282         }
283
284         D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",writtenlen?writtenlen:ret));
285         return writtenlen?writtenlen:ret;
286 }