| 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 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 14 | |
| 15 | #include <linux/kernel.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 | static int jffs2_write_end(struct file *filp, struct address_space *mapping, |
| 25 | loff_t pos, unsigned len, unsigned copied, |
| 26 | struct page *pg, void *fsdata); |
| 27 | static int jffs2_write_begin(struct file *filp, struct address_space *mapping, |
| 28 | loff_t pos, unsigned len, unsigned flags, |
| 29 | struct page **pagep, void **fsdata); |
| 30 | static int jffs2_readpage (struct file *filp, struct page *pg); |
| 31 | |
| 32 | int jffs2_fsync(struct file *filp, loff_t start, loff_t end, int datasync) |
| 33 | { |
| 34 | struct inode *inode = filp->f_mapping->host; |
| 35 | struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); |
| 36 | int ret; |
| 37 | |
| 38 | ret = filemap_write_and_wait_range(inode->i_mapping, start, end); |
| 39 | if (ret) |
| 40 | return ret; |
| 41 | |
| 42 | inode_lock(inode); |
| 43 | /* Trigger GC to flush any pending writes for this inode */ |
| 44 | jffs2_flush_wbuf_gc(c, inode->i_ino); |
| 45 | inode_unlock(inode); |
| 46 | |
| 47 | return 0; |
| 48 | } |
| 49 | |
| 50 | const struct file_operations jffs2_file_operations = |
| 51 | { |
| 52 | .llseek = generic_file_llseek, |
| 53 | .open = generic_file_open, |
| 54 | .read_iter = generic_file_read_iter, |
| 55 | .write_iter = generic_file_write_iter, |
| 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 | .get_acl = jffs2_get_acl, |
| 67 | .set_acl = jffs2_set_acl, |
| 68 | .setattr = jffs2_setattr, |
| 69 | .setxattr = jffs2_setxattr, |
| 70 | .getxattr = jffs2_getxattr, |
| 71 | .listxattr = jffs2_listxattr, |
| 72 | .removexattr = jffs2_removexattr |
| 73 | }; |
| 74 | |
| 75 | const struct address_space_operations jffs2_file_address_operations = |
| 76 | { |
| 77 | .readpage = jffs2_readpage, |
| 78 | .write_begin = jffs2_write_begin, |
| 79 | .write_end = jffs2_write_end, |
| 80 | }; |
| 81 | |
| 82 | static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg) |
| 83 | { |
| 84 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); |
| 85 | struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); |
| 86 | unsigned char *pg_buf; |
| 87 | int ret; |
| 88 | |
| 89 | jffs2_dbg(2, "%s(): ino #%lu, page at offset 0x%lx\n", |
| 90 | __func__, inode->i_ino, pg->index << PAGE_SHIFT); |
| 91 | |
| 92 | BUG_ON(!PageLocked(pg)); |
| 93 | |
| 94 | pg_buf = kmap(pg); |
| 95 | /* FIXME: Can kmap fail? */ |
| 96 | |
| 97 | ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_SHIFT, |
| 98 | PAGE_SIZE); |
| 99 | |
| 100 | if (ret) { |
| 101 | ClearPageUptodate(pg); |
| 102 | SetPageError(pg); |
| 103 | } else { |
| 104 | SetPageUptodate(pg); |
| 105 | ClearPageError(pg); |
| 106 | } |
| 107 | |
| 108 | flush_dcache_page(pg); |
| 109 | kunmap(pg); |
| 110 | |
| 111 | jffs2_dbg(2, "readpage finished\n"); |
| 112 | return ret; |
| 113 | } |
| 114 | |
| 115 | int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg) |
| 116 | { |
| 117 | int ret = jffs2_do_readpage_nolock(inode, pg); |
| 118 | unlock_page(pg); |
| 119 | return ret; |
| 120 | } |
| 121 | |
| 122 | |
| 123 | static int jffs2_readpage (struct file *filp, struct page *pg) |
| 124 | { |
| 125 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host); |
| 126 | int ret; |
| 127 | |
| 128 | mutex_lock(&f->sem); |
| 129 | ret = jffs2_do_readpage_unlock(pg->mapping->host, pg); |
| 130 | mutex_unlock(&f->sem); |
| 131 | return ret; |
| 132 | } |
| 133 | |
| 134 | static int jffs2_write_begin(struct file *filp, struct address_space *mapping, |
| 135 | loff_t pos, unsigned len, unsigned flags, |
| 136 | struct page **pagep, void **fsdata) |
| 137 | { |
| 138 | struct page *pg; |
| 139 | struct inode *inode = mapping->host; |
| 140 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); |
| 141 | pgoff_t index = pos >> PAGE_SHIFT; |
| 142 | uint32_t pageofs = index << PAGE_SHIFT; |
| 143 | int ret = 0; |
| 144 | |
| 145 | pg = grab_cache_page_write_begin(mapping, index, flags); |
| 146 | if (!pg) |
| 147 | return -ENOMEM; |
| 148 | *pagep = pg; |
| 149 | |
| 150 | jffs2_dbg(1, "%s()\n", __func__); |
| 151 | |
| 152 | if (pageofs > inode->i_size) { |
| 153 | /* Make new hole frag from old EOF to new page */ |
| 154 | struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); |
| 155 | struct jffs2_raw_inode ri; |
| 156 | struct jffs2_full_dnode *fn; |
| 157 | uint32_t alloc_len; |
| 158 | |
| 159 | jffs2_dbg(1, "Writing new hole frag 0x%x-0x%x between current EOF and new page\n", |
| 160 | (unsigned int)inode->i_size, pageofs); |
| 161 | |
| 162 | ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len, |
| 163 | ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); |
| 164 | if (ret) |
| 165 | goto out_page; |
| 166 | |
| 167 | mutex_lock(&f->sem); |
| 168 | memset(&ri, 0, sizeof(ri)); |
| 169 | |
| 170 | ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); |
| 171 | ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE); |
| 172 | ri.totlen = cpu_to_je32(sizeof(ri)); |
| 173 | ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4)); |
| 174 | |
| 175 | ri.ino = cpu_to_je32(f->inocache->ino); |
| 176 | ri.version = cpu_to_je32(++f->highest_version); |
| 177 | ri.mode = cpu_to_jemode(inode->i_mode); |
| 178 | ri.uid = cpu_to_je16(i_uid_read(inode)); |
| 179 | ri.gid = cpu_to_je16(i_gid_read(inode)); |
| 180 | ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs)); |
| 181 | ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds()); |
| 182 | ri.offset = cpu_to_je32(inode->i_size); |
| 183 | ri.dsize = cpu_to_je32(pageofs - inode->i_size); |
| 184 | ri.csize = cpu_to_je32(0); |
| 185 | ri.compr = JFFS2_COMPR_ZERO; |
| 186 | ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8)); |
| 187 | ri.data_crc = cpu_to_je32(0); |
| 188 | |
| 189 | fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL); |
| 190 | |
| 191 | if (IS_ERR(fn)) { |
| 192 | ret = PTR_ERR(fn); |
| 193 | jffs2_complete_reservation(c); |
| 194 | mutex_unlock(&f->sem); |
| 195 | goto out_page; |
| 196 | } |
| 197 | ret = jffs2_add_full_dnode_to_inode(c, f, fn); |
| 198 | if (f->metadata) { |
| 199 | jffs2_mark_node_obsolete(c, f->metadata->raw); |
| 200 | jffs2_free_full_dnode(f->metadata); |
| 201 | f->metadata = NULL; |
| 202 | } |
| 203 | if (ret) { |
| 204 | jffs2_dbg(1, "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n", |
| 205 | ret); |
| 206 | jffs2_mark_node_obsolete(c, fn->raw); |
| 207 | jffs2_free_full_dnode(fn); |
| 208 | jffs2_complete_reservation(c); |
| 209 | mutex_unlock(&f->sem); |
| 210 | goto out_page; |
| 211 | } |
| 212 | jffs2_complete_reservation(c); |
| 213 | inode->i_size = pageofs; |
| 214 | mutex_unlock(&f->sem); |
| 215 | } |
| 216 | |
| 217 | /* |
| 218 | * Read in the page if it wasn't already present. Cannot optimize away |
| 219 | * the whole page write case until jffs2_write_end can handle the |
| 220 | * case of a short-copy. |
| 221 | */ |
| 222 | if (!PageUptodate(pg)) { |
| 223 | mutex_lock(&f->sem); |
| 224 | ret = jffs2_do_readpage_nolock(inode, pg); |
| 225 | mutex_unlock(&f->sem); |
| 226 | if (ret) |
| 227 | goto out_page; |
| 228 | } |
| 229 | jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags); |
| 230 | return ret; |
| 231 | |
| 232 | out_page: |
| 233 | unlock_page(pg); |
| 234 | put_page(pg); |
| 235 | return ret; |
| 236 | } |
| 237 | |
| 238 | static int jffs2_write_end(struct file *filp, struct address_space *mapping, |
| 239 | loff_t pos, unsigned len, unsigned copied, |
| 240 | struct page *pg, void *fsdata) |
| 241 | { |
| 242 | /* Actually commit the write from the page cache page we're looking at. |
| 243 | * For now, we write the full page out each time. It sucks, but it's simple |
| 244 | */ |
| 245 | struct inode *inode = mapping->host; |
| 246 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); |
| 247 | struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); |
| 248 | struct jffs2_raw_inode *ri; |
| 249 | unsigned start = pos & (PAGE_SIZE - 1); |
| 250 | unsigned end = start + copied; |
| 251 | unsigned aligned_start = start & ~3; |
| 252 | int ret = 0; |
| 253 | uint32_t writtenlen = 0; |
| 254 | |
| 255 | jffs2_dbg(1, "%s(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n", |
| 256 | __func__, inode->i_ino, pg->index << PAGE_SHIFT, |
| 257 | start, end, pg->flags); |
| 258 | |
| 259 | /* We need to avoid deadlock with page_cache_read() in |
| 260 | jffs2_garbage_collect_pass(). So the page must be |
| 261 | up to date to prevent page_cache_read() from trying |
| 262 | to re-lock it. */ |
| 263 | BUG_ON(!PageUptodate(pg)); |
| 264 | |
| 265 | if (end == PAGE_SIZE) { |
| 266 | /* When writing out the end of a page, write out the |
| 267 | _whole_ page. This helps to reduce the number of |
| 268 | nodes in files which have many short writes, like |
| 269 | syslog files. */ |
| 270 | aligned_start = 0; |
| 271 | } |
| 272 | |
| 273 | ri = jffs2_alloc_raw_inode(); |
| 274 | |
| 275 | if (!ri) { |
| 276 | jffs2_dbg(1, "%s(): Allocation of raw inode failed\n", |
| 277 | __func__); |
| 278 | unlock_page(pg); |
| 279 | put_page(pg); |
| 280 | return -ENOMEM; |
| 281 | } |
| 282 | |
| 283 | /* Set the fields that the generic jffs2_write_inode_range() code can't find */ |
| 284 | ri->ino = cpu_to_je32(inode->i_ino); |
| 285 | ri->mode = cpu_to_jemode(inode->i_mode); |
| 286 | ri->uid = cpu_to_je16(i_uid_read(inode)); |
| 287 | ri->gid = cpu_to_je16(i_gid_read(inode)); |
| 288 | ri->isize = cpu_to_je32((uint32_t)inode->i_size); |
| 289 | ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds()); |
| 290 | |
| 291 | /* In 2.4, it was already kmapped by generic_file_write(). Doesn't |
| 292 | hurt to do it again. The alternative is ifdefs, which are ugly. */ |
| 293 | kmap(pg); |
| 294 | |
| 295 | ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start, |
| 296 | (pg->index << PAGE_SHIFT) + aligned_start, |
| 297 | end - aligned_start, &writtenlen); |
| 298 | |
| 299 | kunmap(pg); |
| 300 | |
| 301 | if (ret) { |
| 302 | /* There was an error writing. */ |
| 303 | SetPageError(pg); |
| 304 | } |
| 305 | |
| 306 | /* Adjust writtenlen for the padding we did, so we don't confuse our caller */ |
| 307 | writtenlen -= min(writtenlen, (start - aligned_start)); |
| 308 | |
| 309 | if (writtenlen) { |
| 310 | if (inode->i_size < pos + writtenlen) { |
| 311 | inode->i_size = pos + writtenlen; |
| 312 | inode->i_blocks = (inode->i_size + 511) >> 9; |
| 313 | |
| 314 | inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime)); |
| 315 | } |
| 316 | } |
| 317 | |
| 318 | jffs2_free_raw_inode(ri); |
| 319 | |
| 320 | if (start+writtenlen < end) { |
| 321 | /* generic_file_write has written more to the page cache than we've |
| 322 | actually written to the medium. Mark the page !Uptodate so that |
| 323 | it gets reread */ |
| 324 | jffs2_dbg(1, "%s(): Not all bytes written. Marking page !uptodate\n", |
| 325 | __func__); |
| 326 | SetPageError(pg); |
| 327 | ClearPageUptodate(pg); |
| 328 | } |
| 329 | |
| 330 | jffs2_dbg(1, "%s() returning %d\n", |
| 331 | __func__, writtenlen > 0 ? writtenlen : ret); |
| 332 | unlock_page(pg); |
| 333 | put_page(pg); |
| 334 | return writtenlen > 0 ? writtenlen : ret; |
| 335 | } |