Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2005, 2006 |
Boaz Harrosh | 27d2e14 | 2009-06-14 17:23:09 +0300 | [diff] [blame] | 3 | * Avishay Traeger (avishay@gmail.com) |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 4 | * Copyright (C) 2008, 2009 |
Boaz Harrosh | aa281ac | 2014-10-19 19:38:58 +0300 | [diff] [blame] | 5 | * Boaz Harrosh <ooo@electrozaur.com> |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 6 | * |
| 7 | * Copyrights for code taken from ext2: |
| 8 | * Copyright (C) 1992, 1993, 1994, 1995 |
| 9 | * Remy Card (card@masi.ibp.fr) |
| 10 | * Laboratoire MASI - Institut Blaise Pascal |
| 11 | * Universite Pierre et Marie Curie (Paris VI) |
| 12 | * from |
| 13 | * linux/fs/minix/inode.c |
| 14 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 15 | * |
| 16 | * This file is part of exofs. |
| 17 | * |
| 18 | * exofs is free software; you can redistribute it and/or modify |
| 19 | * it under the terms of the GNU General Public License as published by |
| 20 | * the Free Software Foundation. Since it is based on ext2, and the only |
| 21 | * valid version of GPL for the Linux kernel is version 2, the only valid |
| 22 | * version of GPL for exofs is version 2. |
| 23 | * |
| 24 | * exofs is distributed in the hope that it will be useful, |
| 25 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 26 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 27 | * GNU General Public License for more details. |
| 28 | * |
| 29 | * You should have received a copy of the GNU General Public License |
| 30 | * along with exofs; if not, write to the Free Software |
| 31 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 32 | */ |
| 33 | |
| 34 | #include "exofs.h" |
| 35 | |
| 36 | static inline unsigned exofs_chunk_size(struct inode *inode) |
| 37 | { |
| 38 | return inode->i_sb->s_blocksize; |
| 39 | } |
| 40 | |
| 41 | static inline void exofs_put_page(struct page *page) |
| 42 | { |
| 43 | kunmap(page); |
| 44 | page_cache_release(page); |
| 45 | } |
| 46 | |
| 47 | /* Accesses dir's inode->i_size must be called under inode lock */ |
| 48 | static inline unsigned long dir_pages(struct inode *inode) |
| 49 | { |
| 50 | return (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
| 51 | } |
| 52 | |
| 53 | static unsigned exofs_last_byte(struct inode *inode, unsigned long page_nr) |
| 54 | { |
| 55 | loff_t last_byte = inode->i_size; |
| 56 | |
| 57 | last_byte -= page_nr << PAGE_CACHE_SHIFT; |
| 58 | if (last_byte > PAGE_CACHE_SIZE) |
| 59 | last_byte = PAGE_CACHE_SIZE; |
| 60 | return last_byte; |
| 61 | } |
| 62 | |
| 63 | static int exofs_commit_chunk(struct page *page, loff_t pos, unsigned len) |
| 64 | { |
| 65 | struct address_space *mapping = page->mapping; |
| 66 | struct inode *dir = mapping->host; |
| 67 | int err = 0; |
| 68 | |
| 69 | dir->i_version++; |
| 70 | |
| 71 | if (!PageUptodate(page)) |
| 72 | SetPageUptodate(page); |
| 73 | |
| 74 | if (pos+len > dir->i_size) { |
| 75 | i_size_write(dir, pos+len); |
| 76 | mark_inode_dirty(dir); |
| 77 | } |
| 78 | set_page_dirty(page); |
| 79 | |
| 80 | if (IS_DIRSYNC(dir)) |
| 81 | err = write_one_page(page, 1); |
| 82 | else |
| 83 | unlock_page(page); |
| 84 | |
| 85 | return err; |
| 86 | } |
| 87 | |
| 88 | static void exofs_check_page(struct page *page) |
| 89 | { |
| 90 | struct inode *dir = page->mapping->host; |
| 91 | unsigned chunk_size = exofs_chunk_size(dir); |
| 92 | char *kaddr = page_address(page); |
| 93 | unsigned offs, rec_len; |
| 94 | unsigned limit = PAGE_CACHE_SIZE; |
| 95 | struct exofs_dir_entry *p; |
| 96 | char *error; |
| 97 | |
| 98 | /* if the page is the last one in the directory */ |
| 99 | if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) { |
| 100 | limit = dir->i_size & ~PAGE_CACHE_MASK; |
| 101 | if (limit & (chunk_size - 1)) |
| 102 | goto Ebadsize; |
| 103 | if (!limit) |
| 104 | goto out; |
| 105 | } |
| 106 | for (offs = 0; offs <= limit - EXOFS_DIR_REC_LEN(1); offs += rec_len) { |
| 107 | p = (struct exofs_dir_entry *)(kaddr + offs); |
| 108 | rec_len = le16_to_cpu(p->rec_len); |
| 109 | |
| 110 | if (rec_len < EXOFS_DIR_REC_LEN(1)) |
| 111 | goto Eshort; |
| 112 | if (rec_len & 3) |
| 113 | goto Ealign; |
| 114 | if (rec_len < EXOFS_DIR_REC_LEN(p->name_len)) |
| 115 | goto Enamelen; |
| 116 | if (((offs + rec_len - 1) ^ offs) & ~(chunk_size-1)) |
| 117 | goto Espan; |
| 118 | } |
| 119 | if (offs != limit) |
| 120 | goto Eend; |
| 121 | out: |
| 122 | SetPageChecked(page); |
| 123 | return; |
| 124 | |
| 125 | Ebadsize: |
| 126 | EXOFS_ERR("ERROR [exofs_check_page]: " |
Boaz Harrosh | 0a93551 | 2010-10-26 17:52:41 +0200 | [diff] [blame] | 127 | "size of directory(0x%lx) is not a multiple of chunk size\n", |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 128 | dir->i_ino |
| 129 | ); |
| 130 | goto fail; |
| 131 | Eshort: |
| 132 | error = "rec_len is smaller than minimal"; |
| 133 | goto bad_entry; |
| 134 | Ealign: |
| 135 | error = "unaligned directory entry"; |
| 136 | goto bad_entry; |
| 137 | Enamelen: |
| 138 | error = "rec_len is too small for name_len"; |
| 139 | goto bad_entry; |
| 140 | Espan: |
| 141 | error = "directory entry across blocks"; |
| 142 | goto bad_entry; |
| 143 | bad_entry: |
| 144 | EXOFS_ERR( |
Boaz Harrosh | 0a93551 | 2010-10-26 17:52:41 +0200 | [diff] [blame] | 145 | "ERROR [exofs_check_page]: bad entry in directory(0x%lx): %s - " |
| 146 | "offset=%lu, inode=0x%llu, rec_len=%d, name_len=%d\n", |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 147 | dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs, |
| 148 | _LLU(le64_to_cpu(p->inode_no)), |
| 149 | rec_len, p->name_len); |
| 150 | goto fail; |
| 151 | Eend: |
| 152 | p = (struct exofs_dir_entry *)(kaddr + offs); |
| 153 | EXOFS_ERR("ERROR [exofs_check_page]: " |
Boaz Harrosh | 0a93551 | 2010-10-26 17:52:41 +0200 | [diff] [blame] | 154 | "entry in directory(0x%lx) spans the page boundary" |
| 155 | "offset=%lu, inode=0x%llx\n", |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 156 | dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs, |
| 157 | _LLU(le64_to_cpu(p->inode_no))); |
| 158 | fail: |
| 159 | SetPageChecked(page); |
| 160 | SetPageError(page); |
| 161 | } |
| 162 | |
| 163 | static struct page *exofs_get_page(struct inode *dir, unsigned long n) |
| 164 | { |
| 165 | struct address_space *mapping = dir->i_mapping; |
| 166 | struct page *page = read_mapping_page(mapping, n, NULL); |
| 167 | |
| 168 | if (!IS_ERR(page)) { |
| 169 | kmap(page); |
| 170 | if (!PageChecked(page)) |
| 171 | exofs_check_page(page); |
| 172 | if (PageError(page)) |
| 173 | goto fail; |
| 174 | } |
| 175 | return page; |
| 176 | |
| 177 | fail: |
| 178 | exofs_put_page(page); |
| 179 | return ERR_PTR(-EIO); |
| 180 | } |
| 181 | |
| 182 | static inline int exofs_match(int len, const unsigned char *name, |
| 183 | struct exofs_dir_entry *de) |
| 184 | { |
| 185 | if (len != de->name_len) |
| 186 | return 0; |
| 187 | if (!de->inode_no) |
| 188 | return 0; |
| 189 | return !memcmp(name, de->name, len); |
| 190 | } |
| 191 | |
| 192 | static inline |
| 193 | struct exofs_dir_entry *exofs_next_entry(struct exofs_dir_entry *p) |
| 194 | { |
| 195 | return (struct exofs_dir_entry *)((char *)p + le16_to_cpu(p->rec_len)); |
| 196 | } |
| 197 | |
| 198 | static inline unsigned |
| 199 | exofs_validate_entry(char *base, unsigned offset, unsigned mask) |
| 200 | { |
| 201 | struct exofs_dir_entry *de = (struct exofs_dir_entry *)(base + offset); |
| 202 | struct exofs_dir_entry *p = |
| 203 | (struct exofs_dir_entry *)(base + (offset&mask)); |
| 204 | while ((char *)p < (char *)de) { |
| 205 | if (p->rec_len == 0) |
| 206 | break; |
| 207 | p = exofs_next_entry(p); |
| 208 | } |
| 209 | return (char *)p - base; |
| 210 | } |
| 211 | |
| 212 | static unsigned char exofs_filetype_table[EXOFS_FT_MAX] = { |
| 213 | [EXOFS_FT_UNKNOWN] = DT_UNKNOWN, |
| 214 | [EXOFS_FT_REG_FILE] = DT_REG, |
| 215 | [EXOFS_FT_DIR] = DT_DIR, |
| 216 | [EXOFS_FT_CHRDEV] = DT_CHR, |
| 217 | [EXOFS_FT_BLKDEV] = DT_BLK, |
| 218 | [EXOFS_FT_FIFO] = DT_FIFO, |
| 219 | [EXOFS_FT_SOCK] = DT_SOCK, |
| 220 | [EXOFS_FT_SYMLINK] = DT_LNK, |
| 221 | }; |
| 222 | |
| 223 | #define S_SHIFT 12 |
| 224 | static unsigned char exofs_type_by_mode[S_IFMT >> S_SHIFT] = { |
| 225 | [S_IFREG >> S_SHIFT] = EXOFS_FT_REG_FILE, |
| 226 | [S_IFDIR >> S_SHIFT] = EXOFS_FT_DIR, |
| 227 | [S_IFCHR >> S_SHIFT] = EXOFS_FT_CHRDEV, |
| 228 | [S_IFBLK >> S_SHIFT] = EXOFS_FT_BLKDEV, |
| 229 | [S_IFIFO >> S_SHIFT] = EXOFS_FT_FIFO, |
| 230 | [S_IFSOCK >> S_SHIFT] = EXOFS_FT_SOCK, |
| 231 | [S_IFLNK >> S_SHIFT] = EXOFS_FT_SYMLINK, |
| 232 | }; |
| 233 | |
| 234 | static inline |
| 235 | void exofs_set_de_type(struct exofs_dir_entry *de, struct inode *inode) |
| 236 | { |
Al Viro | bef41c2 | 2011-07-26 03:07:49 -0400 | [diff] [blame] | 237 | umode_t mode = inode->i_mode; |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 238 | de->file_type = exofs_type_by_mode[(mode & S_IFMT) >> S_SHIFT]; |
| 239 | } |
| 240 | |
| 241 | static int |
Al Viro | 75811d4 | 2013-05-16 13:48:17 -0400 | [diff] [blame] | 242 | exofs_readdir(struct file *file, struct dir_context *ctx) |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 243 | { |
Al Viro | 75811d4 | 2013-05-16 13:48:17 -0400 | [diff] [blame] | 244 | loff_t pos = ctx->pos; |
| 245 | struct inode *inode = file_inode(file); |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 246 | unsigned int offset = pos & ~PAGE_CACHE_MASK; |
| 247 | unsigned long n = pos >> PAGE_CACHE_SHIFT; |
| 248 | unsigned long npages = dir_pages(inode); |
| 249 | unsigned chunk_mask = ~(exofs_chunk_size(inode)-1); |
Al Viro | 75811d4 | 2013-05-16 13:48:17 -0400 | [diff] [blame] | 250 | int need_revalidate = (file->f_version != inode->i_version); |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 251 | |
| 252 | if (pos > inode->i_size - EXOFS_DIR_REC_LEN(1)) |
| 253 | return 0; |
| 254 | |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 255 | for ( ; n < npages; n++, offset = 0) { |
| 256 | char *kaddr, *limit; |
| 257 | struct exofs_dir_entry *de; |
| 258 | struct page *page = exofs_get_page(inode, n); |
| 259 | |
| 260 | if (IS_ERR(page)) { |
Boaz Harrosh | 0a93551 | 2010-10-26 17:52:41 +0200 | [diff] [blame] | 261 | EXOFS_ERR("ERROR: bad page in directory(0x%lx)\n", |
| 262 | inode->i_ino); |
Al Viro | 75811d4 | 2013-05-16 13:48:17 -0400 | [diff] [blame] | 263 | ctx->pos += PAGE_CACHE_SIZE - offset; |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 264 | return PTR_ERR(page); |
| 265 | } |
| 266 | kaddr = page_address(page); |
| 267 | if (unlikely(need_revalidate)) { |
| 268 | if (offset) { |
| 269 | offset = exofs_validate_entry(kaddr, offset, |
| 270 | chunk_mask); |
Al Viro | 75811d4 | 2013-05-16 13:48:17 -0400 | [diff] [blame] | 271 | ctx->pos = (n<<PAGE_CACHE_SHIFT) + offset; |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 272 | } |
Al Viro | 75811d4 | 2013-05-16 13:48:17 -0400 | [diff] [blame] | 273 | file->f_version = inode->i_version; |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 274 | need_revalidate = 0; |
| 275 | } |
| 276 | de = (struct exofs_dir_entry *)(kaddr + offset); |
| 277 | limit = kaddr + exofs_last_byte(inode, n) - |
| 278 | EXOFS_DIR_REC_LEN(1); |
| 279 | for (; (char *)de <= limit; de = exofs_next_entry(de)) { |
| 280 | if (de->rec_len == 0) { |
| 281 | EXOFS_ERR("ERROR: " |
Boaz Harrosh | 0a93551 | 2010-10-26 17:52:41 +0200 | [diff] [blame] | 282 | "zero-length entry in directory(0x%lx)\n", |
| 283 | inode->i_ino); |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 284 | exofs_put_page(page); |
| 285 | return -EIO; |
| 286 | } |
| 287 | if (de->inode_no) { |
Al Viro | 75811d4 | 2013-05-16 13:48:17 -0400 | [diff] [blame] | 288 | unsigned char t; |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 289 | |
Al Viro | 75811d4 | 2013-05-16 13:48:17 -0400 | [diff] [blame] | 290 | if (de->file_type < EXOFS_FT_MAX) |
| 291 | t = exofs_filetype_table[de->file_type]; |
| 292 | else |
| 293 | t = DT_UNKNOWN; |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 294 | |
Al Viro | 75811d4 | 2013-05-16 13:48:17 -0400 | [diff] [blame] | 295 | if (!dir_emit(ctx, de->name, de->name_len, |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 296 | le64_to_cpu(de->inode_no), |
Al Viro | 75811d4 | 2013-05-16 13:48:17 -0400 | [diff] [blame] | 297 | t)) { |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 298 | exofs_put_page(page); |
| 299 | return 0; |
| 300 | } |
| 301 | } |
Al Viro | 75811d4 | 2013-05-16 13:48:17 -0400 | [diff] [blame] | 302 | ctx->pos += le16_to_cpu(de->rec_len); |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 303 | } |
| 304 | exofs_put_page(page); |
| 305 | } |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 306 | return 0; |
| 307 | } |
| 308 | |
| 309 | struct exofs_dir_entry *exofs_find_entry(struct inode *dir, |
| 310 | struct dentry *dentry, struct page **res_page) |
| 311 | { |
| 312 | const unsigned char *name = dentry->d_name.name; |
| 313 | int namelen = dentry->d_name.len; |
| 314 | unsigned reclen = EXOFS_DIR_REC_LEN(namelen); |
| 315 | unsigned long start, n; |
| 316 | unsigned long npages = dir_pages(dir); |
| 317 | struct page *page = NULL; |
| 318 | struct exofs_i_info *oi = exofs_i(dir); |
| 319 | struct exofs_dir_entry *de; |
| 320 | |
| 321 | if (npages == 0) |
| 322 | goto out; |
| 323 | |
| 324 | *res_page = NULL; |
| 325 | |
| 326 | start = oi->i_dir_start_lookup; |
| 327 | if (start >= npages) |
| 328 | start = 0; |
| 329 | n = start; |
| 330 | do { |
| 331 | char *kaddr; |
| 332 | page = exofs_get_page(dir, n); |
| 333 | if (!IS_ERR(page)) { |
| 334 | kaddr = page_address(page); |
| 335 | de = (struct exofs_dir_entry *) kaddr; |
| 336 | kaddr += exofs_last_byte(dir, n) - reclen; |
| 337 | while ((char *) de <= kaddr) { |
| 338 | if (de->rec_len == 0) { |
Boaz Harrosh | 0a93551 | 2010-10-26 17:52:41 +0200 | [diff] [blame] | 339 | EXOFS_ERR("ERROR: zero-length entry in " |
| 340 | "directory(0x%lx)\n", |
| 341 | dir->i_ino); |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 342 | exofs_put_page(page); |
| 343 | goto out; |
| 344 | } |
| 345 | if (exofs_match(namelen, name, de)) |
| 346 | goto found; |
| 347 | de = exofs_next_entry(de); |
| 348 | } |
| 349 | exofs_put_page(page); |
| 350 | } |
| 351 | if (++n >= npages) |
| 352 | n = 0; |
| 353 | } while (n != start); |
| 354 | out: |
| 355 | return NULL; |
| 356 | |
| 357 | found: |
| 358 | *res_page = page; |
| 359 | oi->i_dir_start_lookup = n; |
| 360 | return de; |
| 361 | } |
| 362 | |
| 363 | struct exofs_dir_entry *exofs_dotdot(struct inode *dir, struct page **p) |
| 364 | { |
| 365 | struct page *page = exofs_get_page(dir, 0); |
| 366 | struct exofs_dir_entry *de = NULL; |
| 367 | |
| 368 | if (!IS_ERR(page)) { |
| 369 | de = exofs_next_entry( |
| 370 | (struct exofs_dir_entry *)page_address(page)); |
| 371 | *p = page; |
| 372 | } |
| 373 | return de; |
| 374 | } |
| 375 | |
Boaz Harrosh | 8cf74b3 | 2009-03-22 12:47:26 +0200 | [diff] [blame] | 376 | ino_t exofs_parent_ino(struct dentry *child) |
| 377 | { |
| 378 | struct page *page; |
| 379 | struct exofs_dir_entry *de; |
| 380 | ino_t ino; |
| 381 | |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame^] | 382 | de = exofs_dotdot(d_inode(child), &page); |
Boaz Harrosh | 8cf74b3 | 2009-03-22 12:47:26 +0200 | [diff] [blame] | 383 | if (!de) |
| 384 | return 0; |
| 385 | |
| 386 | ino = le64_to_cpu(de->inode_no); |
| 387 | exofs_put_page(page); |
| 388 | return ino; |
| 389 | } |
| 390 | |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 391 | ino_t exofs_inode_by_name(struct inode *dir, struct dentry *dentry) |
| 392 | { |
| 393 | ino_t res = 0; |
| 394 | struct exofs_dir_entry *de; |
| 395 | struct page *page; |
| 396 | |
| 397 | de = exofs_find_entry(dir, dentry, &page); |
| 398 | if (de) { |
| 399 | res = le64_to_cpu(de->inode_no); |
| 400 | exofs_put_page(page); |
| 401 | } |
| 402 | return res; |
| 403 | } |
| 404 | |
| 405 | int exofs_set_link(struct inode *dir, struct exofs_dir_entry *de, |
| 406 | struct page *page, struct inode *inode) |
| 407 | { |
| 408 | loff_t pos = page_offset(page) + |
| 409 | (char *) de - (char *) page_address(page); |
| 410 | unsigned len = le16_to_cpu(de->rec_len); |
| 411 | int err; |
| 412 | |
| 413 | lock_page(page); |
| 414 | err = exofs_write_begin(NULL, page->mapping, pos, len, |
| 415 | AOP_FLAG_UNINTERRUPTIBLE, &page, NULL); |
| 416 | if (err) |
Joe Perches | 571f7f4 | 2010-10-21 22:17:17 -0700 | [diff] [blame] | 417 | EXOFS_ERR("exofs_set_link: exofs_write_begin FAILED => %d\n", |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 418 | err); |
| 419 | |
| 420 | de->inode_no = cpu_to_le64(inode->i_ino); |
| 421 | exofs_set_de_type(de, inode); |
| 422 | if (likely(!err)) |
| 423 | err = exofs_commit_chunk(page, pos, len); |
| 424 | exofs_put_page(page); |
| 425 | dir->i_mtime = dir->i_ctime = CURRENT_TIME; |
| 426 | mark_inode_dirty(dir); |
| 427 | return err; |
| 428 | } |
| 429 | |
| 430 | int exofs_add_link(struct dentry *dentry, struct inode *inode) |
| 431 | { |
David Howells | 2b0143b | 2015-03-17 22:25:59 +0000 | [diff] [blame^] | 432 | struct inode *dir = d_inode(dentry->d_parent); |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 433 | const unsigned char *name = dentry->d_name.name; |
| 434 | int namelen = dentry->d_name.len; |
| 435 | unsigned chunk_size = exofs_chunk_size(dir); |
| 436 | unsigned reclen = EXOFS_DIR_REC_LEN(namelen); |
| 437 | unsigned short rec_len, name_len; |
| 438 | struct page *page = NULL; |
| 439 | struct exofs_sb_info *sbi = inode->i_sb->s_fs_info; |
| 440 | struct exofs_dir_entry *de; |
| 441 | unsigned long npages = dir_pages(dir); |
| 442 | unsigned long n; |
| 443 | char *kaddr; |
| 444 | loff_t pos; |
| 445 | int err; |
| 446 | |
| 447 | for (n = 0; n <= npages; n++) { |
| 448 | char *dir_end; |
| 449 | |
| 450 | page = exofs_get_page(dir, n); |
| 451 | err = PTR_ERR(page); |
| 452 | if (IS_ERR(page)) |
| 453 | goto out; |
| 454 | lock_page(page); |
| 455 | kaddr = page_address(page); |
| 456 | dir_end = kaddr + exofs_last_byte(dir, n); |
| 457 | de = (struct exofs_dir_entry *)kaddr; |
| 458 | kaddr += PAGE_CACHE_SIZE - reclen; |
| 459 | while ((char *)de <= kaddr) { |
| 460 | if ((char *)de == dir_end) { |
| 461 | name_len = 0; |
| 462 | rec_len = chunk_size; |
| 463 | de->rec_len = cpu_to_le16(chunk_size); |
| 464 | de->inode_no = 0; |
| 465 | goto got_it; |
| 466 | } |
| 467 | if (de->rec_len == 0) { |
| 468 | EXOFS_ERR("ERROR: exofs_add_link: " |
Boaz Harrosh | 0a93551 | 2010-10-26 17:52:41 +0200 | [diff] [blame] | 469 | "zero-length entry in directory(0x%lx)\n", |
| 470 | inode->i_ino); |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 471 | err = -EIO; |
| 472 | goto out_unlock; |
| 473 | } |
| 474 | err = -EEXIST; |
| 475 | if (exofs_match(namelen, name, de)) |
| 476 | goto out_unlock; |
| 477 | name_len = EXOFS_DIR_REC_LEN(de->name_len); |
| 478 | rec_len = le16_to_cpu(de->rec_len); |
| 479 | if (!de->inode_no && rec_len >= reclen) |
| 480 | goto got_it; |
| 481 | if (rec_len >= name_len + reclen) |
| 482 | goto got_it; |
| 483 | de = (struct exofs_dir_entry *) ((char *) de + rec_len); |
| 484 | } |
| 485 | unlock_page(page); |
| 486 | exofs_put_page(page); |
| 487 | } |
| 488 | |
Boaz Harrosh | 0a93551 | 2010-10-26 17:52:41 +0200 | [diff] [blame] | 489 | EXOFS_ERR("exofs_add_link: BAD dentry=%p or inode=0x%lx\n", |
| 490 | dentry, inode->i_ino); |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 491 | return -EINVAL; |
| 492 | |
| 493 | got_it: |
| 494 | pos = page_offset(page) + |
| 495 | (char *)de - (char *)page_address(page); |
| 496 | err = exofs_write_begin(NULL, page->mapping, pos, rec_len, 0, |
| 497 | &page, NULL); |
| 498 | if (err) |
| 499 | goto out_unlock; |
| 500 | if (de->inode_no) { |
| 501 | struct exofs_dir_entry *de1 = |
| 502 | (struct exofs_dir_entry *)((char *)de + name_len); |
| 503 | de1->rec_len = cpu_to_le16(rec_len - name_len); |
| 504 | de->rec_len = cpu_to_le16(name_len); |
| 505 | de = de1; |
| 506 | } |
| 507 | de->name_len = namelen; |
| 508 | memcpy(de->name, name, namelen); |
| 509 | de->inode_no = cpu_to_le64(inode->i_ino); |
| 510 | exofs_set_de_type(de, inode); |
| 511 | err = exofs_commit_chunk(page, pos, rec_len); |
| 512 | dir->i_mtime = dir->i_ctime = CURRENT_TIME; |
| 513 | mark_inode_dirty(dir); |
| 514 | sbi->s_numfiles++; |
| 515 | |
| 516 | out_put: |
| 517 | exofs_put_page(page); |
| 518 | out: |
| 519 | return err; |
| 520 | out_unlock: |
| 521 | unlock_page(page); |
| 522 | goto out_put; |
| 523 | } |
| 524 | |
| 525 | int exofs_delete_entry(struct exofs_dir_entry *dir, struct page *page) |
| 526 | { |
| 527 | struct address_space *mapping = page->mapping; |
| 528 | struct inode *inode = mapping->host; |
| 529 | struct exofs_sb_info *sbi = inode->i_sb->s_fs_info; |
| 530 | char *kaddr = page_address(page); |
| 531 | unsigned from = ((char *)dir - kaddr) & ~(exofs_chunk_size(inode)-1); |
| 532 | unsigned to = ((char *)dir - kaddr) + le16_to_cpu(dir->rec_len); |
| 533 | loff_t pos; |
| 534 | struct exofs_dir_entry *pde = NULL; |
| 535 | struct exofs_dir_entry *de = (struct exofs_dir_entry *) (kaddr + from); |
| 536 | int err; |
| 537 | |
| 538 | while (de < dir) { |
| 539 | if (de->rec_len == 0) { |
| 540 | EXOFS_ERR("ERROR: exofs_delete_entry:" |
Boaz Harrosh | 0a93551 | 2010-10-26 17:52:41 +0200 | [diff] [blame] | 541 | "zero-length entry in directory(0x%lx)\n", |
| 542 | inode->i_ino); |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 543 | err = -EIO; |
| 544 | goto out; |
| 545 | } |
| 546 | pde = de; |
| 547 | de = exofs_next_entry(de); |
| 548 | } |
| 549 | if (pde) |
| 550 | from = (char *)pde - (char *)page_address(page); |
| 551 | pos = page_offset(page) + from; |
| 552 | lock_page(page); |
| 553 | err = exofs_write_begin(NULL, page->mapping, pos, to - from, 0, |
| 554 | &page, NULL); |
| 555 | if (err) |
Joe Perches | 571f7f4 | 2010-10-21 22:17:17 -0700 | [diff] [blame] | 556 | EXOFS_ERR("exofs_delete_entry: exofs_write_begin FAILED => %d\n", |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 557 | err); |
| 558 | if (pde) |
| 559 | pde->rec_len = cpu_to_le16(to - from); |
| 560 | dir->inode_no = 0; |
| 561 | if (likely(!err)) |
| 562 | err = exofs_commit_chunk(page, pos, to - from); |
| 563 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
| 564 | mark_inode_dirty(inode); |
| 565 | sbi->s_numfiles--; |
| 566 | out: |
| 567 | exofs_put_page(page); |
| 568 | return err; |
| 569 | } |
| 570 | |
| 571 | /* kept aligned on 4 bytes */ |
| 572 | #define THIS_DIR ".\0\0" |
| 573 | #define PARENT_DIR "..\0" |
| 574 | |
| 575 | int exofs_make_empty(struct inode *inode, struct inode *parent) |
| 576 | { |
| 577 | struct address_space *mapping = inode->i_mapping; |
| 578 | struct page *page = grab_cache_page(mapping, 0); |
| 579 | unsigned chunk_size = exofs_chunk_size(inode); |
| 580 | struct exofs_dir_entry *de; |
| 581 | int err; |
| 582 | void *kaddr; |
| 583 | |
| 584 | if (!page) |
| 585 | return -ENOMEM; |
| 586 | |
| 587 | err = exofs_write_begin(NULL, page->mapping, 0, chunk_size, 0, |
| 588 | &page, NULL); |
| 589 | if (err) { |
| 590 | unlock_page(page); |
| 591 | goto fail; |
| 592 | } |
| 593 | |
Cong Wang | bf7014b | 2011-11-25 23:14:29 +0800 | [diff] [blame] | 594 | kaddr = kmap_atomic(page); |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 595 | de = (struct exofs_dir_entry *)kaddr; |
| 596 | de->name_len = 1; |
| 597 | de->rec_len = cpu_to_le16(EXOFS_DIR_REC_LEN(1)); |
| 598 | memcpy(de->name, THIS_DIR, sizeof(THIS_DIR)); |
| 599 | de->inode_no = cpu_to_le64(inode->i_ino); |
| 600 | exofs_set_de_type(de, inode); |
| 601 | |
| 602 | de = (struct exofs_dir_entry *)(kaddr + EXOFS_DIR_REC_LEN(1)); |
| 603 | de->name_len = 2; |
| 604 | de->rec_len = cpu_to_le16(chunk_size - EXOFS_DIR_REC_LEN(1)); |
| 605 | de->inode_no = cpu_to_le64(parent->i_ino); |
| 606 | memcpy(de->name, PARENT_DIR, sizeof(PARENT_DIR)); |
| 607 | exofs_set_de_type(de, inode); |
Cong Wang | bf7014b | 2011-11-25 23:14:29 +0800 | [diff] [blame] | 608 | kunmap_atomic(kaddr); |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 609 | err = exofs_commit_chunk(page, 0, chunk_size); |
| 610 | fail: |
| 611 | page_cache_release(page); |
| 612 | return err; |
| 613 | } |
| 614 | |
| 615 | int exofs_empty_dir(struct inode *inode) |
| 616 | { |
| 617 | struct page *page = NULL; |
| 618 | unsigned long i, npages = dir_pages(inode); |
| 619 | |
| 620 | for (i = 0; i < npages; i++) { |
| 621 | char *kaddr; |
| 622 | struct exofs_dir_entry *de; |
| 623 | page = exofs_get_page(inode, i); |
| 624 | |
| 625 | if (IS_ERR(page)) |
| 626 | continue; |
| 627 | |
| 628 | kaddr = page_address(page); |
| 629 | de = (struct exofs_dir_entry *)kaddr; |
| 630 | kaddr += exofs_last_byte(inode, i) - EXOFS_DIR_REC_LEN(1); |
| 631 | |
| 632 | while ((char *)de <= kaddr) { |
| 633 | if (de->rec_len == 0) { |
| 634 | EXOFS_ERR("ERROR: exofs_empty_dir: " |
| 635 | "zero-length directory entry" |
| 636 | "kaddr=%p, de=%p\n", kaddr, de); |
| 637 | goto not_empty; |
| 638 | } |
| 639 | if (de->inode_no != 0) { |
| 640 | /* check for . and .. */ |
| 641 | if (de->name[0] != '.') |
| 642 | goto not_empty; |
| 643 | if (de->name_len > 2) |
| 644 | goto not_empty; |
| 645 | if (de->name_len < 2) { |
| 646 | if (le64_to_cpu(de->inode_no) != |
| 647 | inode->i_ino) |
| 648 | goto not_empty; |
| 649 | } else if (de->name[1] != '.') |
| 650 | goto not_empty; |
| 651 | } |
| 652 | de = exofs_next_entry(de); |
| 653 | } |
| 654 | exofs_put_page(page); |
| 655 | } |
| 656 | return 1; |
| 657 | |
| 658 | not_empty: |
| 659 | exofs_put_page(page); |
| 660 | return 0; |
| 661 | } |
| 662 | |
| 663 | const struct file_operations exofs_dir_operations = { |
| 664 | .llseek = generic_file_llseek, |
| 665 | .read = generic_read_dir, |
Al Viro | 75811d4 | 2013-05-16 13:48:17 -0400 | [diff] [blame] | 666 | .iterate = exofs_readdir, |
Boaz Harrosh | e6af00f | 2008-10-28 15:38:12 +0200 | [diff] [blame] | 667 | }; |