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, int datasync) 30 { 31 struct inode *inode = filp->f_mapping->host; 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 } 321