include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[linux-3.10.git] / fs / jffs2 / file.c
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2001-2007 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  */
11
12 #include <linux/kernel.h>
13 #include <linux/fs.h>
14 #include <linux/time.h>
15 #include <linux/pagemap.h>
16 #include <linux/highmem.h>
17 #include <linux/crc32.h>
18 #include <linux/jffs2.h>
19 #include "nodelist.h"
20
21 static int jffs2_write_end(struct file *filp, struct address_space *mapping,
22                         loff_t pos, unsigned len, unsigned copied,
23                         struct page *pg, void *fsdata);
24 static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
25                         loff_t pos, unsigned len, unsigned flags,
26                         struct page **pagep, void **fsdata);
27 static int jffs2_readpage (struct file *filp, struct page *pg);
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 const struct file_operations jffs2_file_operations =
41 {
42         .llseek =       generic_file_llseek,
43         .open =         generic_file_open,
44         .read =         do_sync_read,
45         .aio_read =     generic_file_aio_read,
46         .write =        do_sync_write,
47         .aio_write =    generic_file_aio_write,
48         .unlocked_ioctl=jffs2_ioctl,
49         .mmap =         generic_file_readonly_mmap,
50         .fsync =        jffs2_fsync,
51         .splice_read =  generic_file_splice_read,
52 };
53
54 /* jffs2_file_inode_operations */
55
56 const struct inode_operations jffs2_file_inode_operations =
57 {
58         .check_acl =    jffs2_check_acl,
59         .setattr =      jffs2_setattr,
60         .setxattr =     jffs2_setxattr,
61         .getxattr =     jffs2_getxattr,
62         .listxattr =    jffs2_listxattr,
63         .removexattr =  jffs2_removexattr
64 };
65
66 const struct address_space_operations jffs2_file_address_operations =
67 {
68         .readpage =     jffs2_readpage,
69         .write_begin =  jffs2_write_begin,
70         .write_end =    jffs2_write_end,
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         BUG_ON(!PageLocked(pg));
83
84         pg_buf = kmap(pg);
85         /* FIXME: Can kmap fail? */
86
87         ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
88
89         if (ret) {
90                 ClearPageUptodate(pg);
91                 SetPageError(pg);
92         } else {
93                 SetPageUptodate(pg);
94                 ClearPageError(pg);
95         }
96
97         flush_dcache_page(pg);
98         kunmap(pg);
99
100         D2(printk(KERN_DEBUG "readpage finished\n"));
101         return ret;
102 }
103
104 int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg)
105 {
106         int ret = jffs2_do_readpage_nolock(inode, pg);
107         unlock_page(pg);
108         return ret;
109 }
110
111
112 static int jffs2_readpage (struct file *filp, struct page *pg)
113 {
114         struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
115         int ret;
116
117         mutex_lock(&f->sem);
118         ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
119         mutex_unlock(&f->sem);
120         return ret;
121 }
122
123 static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
124                         loff_t pos, unsigned len, unsigned flags,
125                         struct page **pagep, void **fsdata)
126 {
127         struct page *pg;
128         struct inode *inode = mapping->host;
129         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
130         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
131         uint32_t pageofs = index << PAGE_CACHE_SHIFT;
132         int ret = 0;
133
134         pg = grab_cache_page_write_begin(mapping, index, flags);
135         if (!pg)
136                 return -ENOMEM;
137         *pagep = pg;
138
139         D1(printk(KERN_DEBUG "jffs2_write_begin()\n"));
140
141         if (pageofs > inode->i_size) {
142                 /* Make new hole frag from old EOF to new page */
143                 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
144                 struct jffs2_raw_inode ri;
145                 struct jffs2_full_dnode *fn;
146                 uint32_t alloc_len;
147
148                 D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
149                           (unsigned int)inode->i_size, pageofs));
150
151                 ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
152                                           ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
153                 if (ret)
154                         goto out_page;
155
156                 mutex_lock(&f->sem);
157                 memset(&ri, 0, sizeof(ri));
158
159                 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
160                 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
161                 ri.totlen = cpu_to_je32(sizeof(ri));
162                 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
163
164                 ri.ino = cpu_to_je32(f->inocache->ino);
165                 ri.version = cpu_to_je32(++f->highest_version);
166                 ri.mode = cpu_to_jemode(inode->i_mode);
167                 ri.uid = cpu_to_je16(inode->i_uid);
168                 ri.gid = cpu_to_je16(inode->i_gid);
169                 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
170                 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
171                 ri.offset = cpu_to_je32(inode->i_size);
172                 ri.dsize = cpu_to_je32(pageofs - inode->i_size);
173                 ri.csize = cpu_to_je32(0);
174                 ri.compr = JFFS2_COMPR_ZERO;
175                 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
176                 ri.data_crc = cpu_to_je32(0);
177
178                 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL);
179
180                 if (IS_ERR(fn)) {
181                         ret = PTR_ERR(fn);
182                         jffs2_complete_reservation(c);
183                         mutex_unlock(&f->sem);
184                         goto out_page;
185                 }
186                 ret = jffs2_add_full_dnode_to_inode(c, f, fn);
187                 if (f->metadata) {
188                         jffs2_mark_node_obsolete(c, f->metadata->raw);
189                         jffs2_free_full_dnode(f->metadata);
190                         f->metadata = NULL;
191                 }
192                 if (ret) {
193                         D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n", ret));
194                         jffs2_mark_node_obsolete(c, fn->raw);
195                         jffs2_free_full_dnode(fn);
196                         jffs2_complete_reservation(c);
197                         mutex_unlock(&f->sem);
198                         goto out_page;
199                 }
200                 jffs2_complete_reservation(c);
201                 inode->i_size = pageofs;
202                 mutex_unlock(&f->sem);
203         }
204
205         /*
206          * Read in the page if it wasn't already present. Cannot optimize away
207          * the whole page write case until jffs2_write_end can handle the
208          * case of a short-copy.
209          */
210         if (!PageUptodate(pg)) {
211                 mutex_lock(&f->sem);
212                 ret = jffs2_do_readpage_nolock(inode, pg);
213                 mutex_unlock(&f->sem);
214                 if (ret)
215                         goto out_page;
216         }
217         D1(printk(KERN_DEBUG "end write_begin(). pg->flags %lx\n", pg->flags));
218         return ret;
219
220 out_page:
221         unlock_page(pg);
222         page_cache_release(pg);
223         return ret;
224 }
225
226 static int jffs2_write_end(struct file *filp, struct address_space *mapping,
227                         loff_t pos, unsigned len, unsigned copied,
228                         struct page *pg, void *fsdata)
229 {
230         /* Actually commit the write from the page cache page we're looking at.
231          * For now, we write the full page out each time. It sucks, but it's simple
232          */
233         struct inode *inode = mapping->host;
234         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
235         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
236         struct jffs2_raw_inode *ri;
237         unsigned start = pos & (PAGE_CACHE_SIZE - 1);
238         unsigned end = start + copied;
239         unsigned aligned_start = start & ~3;
240         int ret = 0;
241         uint32_t writtenlen = 0;
242
243         D1(printk(KERN_DEBUG "jffs2_write_end(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
244                   inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags));
245
246         /* We need to avoid deadlock with page_cache_read() in
247            jffs2_garbage_collect_pass(). So the page must be
248            up to date to prevent page_cache_read() from trying
249            to re-lock it. */
250         BUG_ON(!PageUptodate(pg));
251
252         if (end == PAGE_CACHE_SIZE) {
253                 /* When writing out the end of a page, write out the
254                    _whole_ page. This helps to reduce the number of
255                    nodes in files which have many short writes, like
256                    syslog files. */
257                 aligned_start = 0;
258         }
259
260         ri = jffs2_alloc_raw_inode();
261
262         if (!ri) {
263                 D1(printk(KERN_DEBUG "jffs2_write_end(): Allocation of raw inode failed\n"));
264                 unlock_page(pg);
265                 page_cache_release(pg);
266                 return -ENOMEM;
267         }
268
269         /* Set the fields that the generic jffs2_write_inode_range() code can't find */
270         ri->ino = cpu_to_je32(inode->i_ino);
271         ri->mode = cpu_to_jemode(inode->i_mode);
272         ri->uid = cpu_to_je16(inode->i_uid);
273         ri->gid = cpu_to_je16(inode->i_gid);
274         ri->isize = cpu_to_je32((uint32_t)inode->i_size);
275         ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
276
277         /* In 2.4, it was already kmapped by generic_file_write(). Doesn't
278            hurt to do it again. The alternative is ifdefs, which are ugly. */
279         kmap(pg);
280
281         ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start,
282                                       (pg->index << PAGE_CACHE_SHIFT) + aligned_start,
283                                       end - aligned_start, &writtenlen);
284
285         kunmap(pg);
286
287         if (ret) {
288                 /* There was an error writing. */
289                 SetPageError(pg);
290         }
291
292         /* Adjust writtenlen for the padding we did, so we don't confuse our caller */
293         writtenlen -= min(writtenlen, (start - aligned_start));
294
295         if (writtenlen) {
296                 if (inode->i_size < pos + writtenlen) {
297                         inode->i_size = pos + writtenlen;
298                         inode->i_blocks = (inode->i_size + 511) >> 9;
299
300                         inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
301                 }
302         }
303
304         jffs2_free_raw_inode(ri);
305
306         if (start+writtenlen < end) {
307                 /* generic_file_write has written more to the page cache than we've
308                    actually written to the medium. Mark the page !Uptodate so that
309                    it gets reread */
310                 D1(printk(KERN_DEBUG "jffs2_write_end(): Not all bytes written. Marking page !uptodate\n"));
311                 SetPageError(pg);
312                 ClearPageUptodate(pg);
313         }
314
315         D1(printk(KERN_DEBUG "jffs2_write_end() returning %d\n",
316                                         writtenlen > 0 ? writtenlen : ret));
317         unlock_page(pg);
318         page_cache_release(pg);
319         return writtenlen > 0 ? writtenlen : ret;
320 }