1 /* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright © 2001-2007 Red Hat, Inc. 5 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org> 6 * 7 * Created by David Woodhouse <dwmw2@infradead.org> 8 * 9 * For licensing information, see the file 'LICENCE' in this directory. 10 * 11 */ 12 13 #include <linux/kernel.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 22 static int jffs2_write_end(struct file *filp, struct address_space *mapping, 23 loff_t pos, unsigned len, unsigned copied, 24 struct page *pg, void *fsdata); 25 static int jffs2_write_begin(struct file *filp, struct address_space *mapping, 26 loff_t pos, unsigned len, unsigned flags, 27 struct page **pagep, void **fsdata); 28 static int jffs2_readpage (struct file *filp, struct page *pg); 29 30 int jffs2_fsync(struct file *filp, loff_t start, loff_t end, int datasync) 31 { 32 struct inode *inode = filp->f_mapping->host; 33 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 34 int ret; 35 36 ret = filemap_write_and_wait_range(inode->i_mapping, start, end); 37 if (ret) 38 return ret; 39 40 mutex_lock(&inode->i_mutex); 41 /* Trigger GC to flush any pending writes for this inode */ 42 jffs2_flush_wbuf_gc(c, inode->i_ino); 43 mutex_unlock(&inode->i_mutex); 44 45 return 0; 46 } 47 48 const struct file_operations jffs2_file_operations = 49 { 50 .llseek = generic_file_llseek, 51 .open = generic_file_open, 52 .read = do_sync_read, 53 .aio_read = generic_file_aio_read, 54 .write = do_sync_write, 55 .aio_write = generic_file_aio_write, 56 .unlocked_ioctl=jffs2_ioctl, 57 .mmap = generic_file_readonly_mmap, 58 .fsync = jffs2_fsync, 59 .splice_read = generic_file_splice_read, 60 }; 61 62 /* jffs2_file_inode_operations */ 63 64 const struct inode_operations jffs2_file_inode_operations = 65 { 66 .check_acl = jffs2_check_acl, 67 .setattr = jffs2_setattr, 68 .setxattr = jffs2_setxattr, 69 .getxattr = jffs2_getxattr, 70 .listxattr = jffs2_listxattr, 71 .removexattr = jffs2_removexattr 72 }; 73 74 const struct address_space_operations jffs2_file_address_operations = 75 { 76 .readpage = jffs2_readpage, 77 .write_begin = jffs2_write_begin, 78 .write_end = jffs2_write_end, 79 }; 80 81 static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg) 82 { 83 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 84 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 85 unsigned char *pg_buf; 86 int ret; 87 88 D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT)); 89 90 BUG_ON(!PageLocked(pg)); 91 92 pg_buf = kmap(pg); 93 /* FIXME: Can kmap fail? */ 94 95 ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE); 96 97 if (ret) { 98 ClearPageUptodate(pg); 99 SetPageError(pg); 100 } else { 101 SetPageUptodate(pg); 102 ClearPageError(pg); 103 } 104 105 flush_dcache_page(pg); 106 kunmap(pg); 107 108 D2(printk(KERN_DEBUG "readpage finished\n")); 109 return ret; 110 } 111 112 int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg) 113 { 114 int ret = jffs2_do_readpage_nolock(inode, pg); 115 unlock_page(pg); 116 return ret; 117 } 118 119 120 static int jffs2_readpage (struct file *filp, struct page *pg) 121 { 122 struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host); 123 int ret; 124 125 mutex_lock(&f->sem); 126 ret = jffs2_do_readpage_unlock(pg->mapping->host, pg); 127 mutex_unlock(&f->sem); 128 return ret; 129 } 130 131 static int jffs2_write_begin(struct file *filp, struct address_space *mapping, 132 loff_t pos, unsigned len, unsigned flags, 133 struct page **pagep, void **fsdata) 134 { 135 struct page *pg; 136 struct inode *inode = mapping->host; 137 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 138 pgoff_t index = pos >> PAGE_CACHE_SHIFT; 139 uint32_t pageofs = index << PAGE_CACHE_SHIFT; 140 int ret = 0; 141 142 pg = grab_cache_page_write_begin(mapping, index, flags); 143 if (!pg) 144 return -ENOMEM; 145 *pagep = pg; 146 147 D1(printk(KERN_DEBUG "jffs2_write_begin()\n")); 148 149 if (pageofs > inode->i_size) { 150 /* Make new hole frag from old EOF to new page */ 151 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 152 struct jffs2_raw_inode ri; 153 struct jffs2_full_dnode *fn; 154 uint32_t alloc_len; 155 156 D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n", 157 (unsigned int)inode->i_size, pageofs)); 158 159 ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len, 160 ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); 161 if (ret) 162 goto out_page; 163 164 mutex_lock(&f->sem); 165 memset(&ri, 0, sizeof(ri)); 166 167 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); 168 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE); 169 ri.totlen = cpu_to_je32(sizeof(ri)); 170 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4)); 171 172 ri.ino = cpu_to_je32(f->inocache->ino); 173 ri.version = cpu_to_je32(++f->highest_version); 174 ri.mode = cpu_to_jemode(inode->i_mode); 175 ri.uid = cpu_to_je16(inode->i_uid); 176 ri.gid = cpu_to_je16(inode->i_gid); 177 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs)); 178 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds()); 179 ri.offset = cpu_to_je32(inode->i_size); 180 ri.dsize = cpu_to_je32(pageofs - inode->i_size); 181 ri.csize = cpu_to_je32(0); 182 ri.compr = JFFS2_COMPR_ZERO; 183 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8)); 184 ri.data_crc = cpu_to_je32(0); 185 186 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL); 187 188 if (IS_ERR(fn)) { 189 ret = PTR_ERR(fn); 190 jffs2_complete_reservation(c); 191 mutex_unlock(&f->sem); 192 goto out_page; 193 } 194 ret = jffs2_add_full_dnode_to_inode(c, f, fn); 195 if (f->metadata) { 196 jffs2_mark_node_obsolete(c, f->metadata->raw); 197 jffs2_free_full_dnode(f->metadata); 198 f->metadata = NULL; 199 } 200 if (ret) { 201 D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n", ret)); 202 jffs2_mark_node_obsolete(c, fn->raw); 203 jffs2_free_full_dnode(fn); 204 jffs2_complete_reservation(c); 205 mutex_unlock(&f->sem); 206 goto out_page; 207 } 208 jffs2_complete_reservation(c); 209 inode->i_size = pageofs; 210 mutex_unlock(&f->sem); 211 } 212 213 /* 214 * Read in the page if it wasn't already present. Cannot optimize away 215 * the whole page write case until jffs2_write_end can handle the 216 * case of a short-copy. 217 */ 218 if (!PageUptodate(pg)) { 219 mutex_lock(&f->sem); 220 ret = jffs2_do_readpage_nolock(inode, pg); 221 mutex_unlock(&f->sem); 222 if (ret) 223 goto out_page; 224 } 225 D1(printk(KERN_DEBUG "end write_begin(). pg->flags %lx\n", pg->flags)); 226 return ret; 227 228 out_page: 229 unlock_page(pg); 230 page_cache_release(pg); 231 return ret; 232 } 233 234 static int jffs2_write_end(struct file *filp, struct address_space *mapping, 235 loff_t pos, unsigned len, unsigned copied, 236 struct page *pg, void *fsdata) 237 { 238 /* Actually commit the write from the page cache page we're looking at. 239 * For now, we write the full page out each time. It sucks, but it's simple 240 */ 241 struct inode *inode = mapping->host; 242 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 243 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 244 struct jffs2_raw_inode *ri; 245 unsigned start = pos & (PAGE_CACHE_SIZE - 1); 246 unsigned end = start + copied; 247 unsigned aligned_start = start & ~3; 248 int ret = 0; 249 uint32_t writtenlen = 0; 250 251 D1(printk(KERN_DEBUG "jffs2_write_end(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n", 252 inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags)); 253 254 /* We need to avoid deadlock with page_cache_read() in 255 jffs2_garbage_collect_pass(). So the page must be 256 up to date to prevent page_cache_read() from trying 257 to re-lock it. */ 258 BUG_ON(!PageUptodate(pg)); 259 260 if (end == PAGE_CACHE_SIZE) { 261 /* When writing out the end of a page, write out the 262 _whole_ page. This helps to reduce the number of 263 nodes in files which have many short writes, like 264 syslog files. */ 265 aligned_start = 0; 266 } 267 268 ri = jffs2_alloc_raw_inode(); 269 270 if (!ri) { 271 D1(printk(KERN_DEBUG "jffs2_write_end(): Allocation of raw inode failed\n")); 272 unlock_page(pg); 273 page_cache_release(pg); 274 return -ENOMEM; 275 } 276 277 /* Set the fields that the generic jffs2_write_inode_range() code can't find */ 278 ri->ino = cpu_to_je32(inode->i_ino); 279 ri->mode = cpu_to_jemode(inode->i_mode); 280 ri->uid = cpu_to_je16(inode->i_uid); 281 ri->gid = cpu_to_je16(inode->i_gid); 282 ri->isize = cpu_to_je32((uint32_t)inode->i_size); 283 ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds()); 284 285 /* In 2.4, it was already kmapped by generic_file_write(). Doesn't 286 hurt to do it again. The alternative is ifdefs, which are ugly. */ 287 kmap(pg); 288 289 ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start, 290 (pg->index << PAGE_CACHE_SHIFT) + aligned_start, 291 end - aligned_start, &writtenlen); 292 293 kunmap(pg); 294 295 if (ret) { 296 /* There was an error writing. */ 297 SetPageError(pg); 298 } 299 300 /* Adjust writtenlen for the padding we did, so we don't confuse our caller */ 301 writtenlen -= min(writtenlen, (start - aligned_start)); 302 303 if (writtenlen) { 304 if (inode->i_size < pos + writtenlen) { 305 inode->i_size = pos + writtenlen; 306 inode->i_blocks = (inode->i_size + 511) >> 9; 307 308 inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime)); 309 } 310 } 311 312 jffs2_free_raw_inode(ri); 313 314 if (start+writtenlen < end) { 315 /* generic_file_write has written more to the page cache than we've 316 actually written to the medium. Mark the page !Uptodate so that 317 it gets reread */ 318 D1(printk(KERN_DEBUG "jffs2_write_end(): Not all bytes written. Marking page !uptodate\n")); 319 SetPageError(pg); 320 ClearPageUptodate(pg); 321 } 322 323 D1(printk(KERN_DEBUG "jffs2_write_end() returning %d\n", 324 writtenlen > 0 ? writtenlen : ret)); 325 unlock_page(pg); 326 page_cache_release(pg); 327 return writtenlen > 0 ? writtenlen : ret; 328 } 329