1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. 4 */ 5 6 #include <linux/slab.h> 7 #include <linux/compat.h> 8 #include <linux/cred.h> 9 #include <linux/buffer_head.h> 10 #include <linux/blkdev.h> 11 12 #include "exfat_raw.h" 13 #include "exfat_fs.h" 14 15 static int exfat_cont_expand(struct inode *inode, loff_t size) 16 { 17 struct address_space *mapping = inode->i_mapping; 18 loff_t start = i_size_read(inode), count = size - i_size_read(inode); 19 int err, err2; 20 21 err = generic_cont_expand_simple(inode, size); 22 if (err) 23 return err; 24 25 inode->i_ctime = inode->i_mtime = current_time(inode); 26 mark_inode_dirty(inode); 27 28 if (!IS_SYNC(inode)) 29 return 0; 30 31 err = filemap_fdatawrite_range(mapping, start, start + count - 1); 32 err2 = sync_mapping_buffers(mapping); 33 if (!err) 34 err = err2; 35 err2 = write_inode_now(inode, 1); 36 if (!err) 37 err = err2; 38 if (err) 39 return err; 40 41 return filemap_fdatawait_range(mapping, start, start + count - 1); 42 } 43 44 static bool exfat_allow_set_time(struct exfat_sb_info *sbi, struct inode *inode) 45 { 46 mode_t allow_utime = sbi->options.allow_utime; 47 48 if (!uid_eq(current_fsuid(), inode->i_uid)) { 49 if (in_group_p(inode->i_gid)) 50 allow_utime >>= 3; 51 if (allow_utime & MAY_WRITE) 52 return true; 53 } 54 55 /* use a default check */ 56 return false; 57 } 58 59 static int exfat_sanitize_mode(const struct exfat_sb_info *sbi, 60 struct inode *inode, umode_t *mode_ptr) 61 { 62 mode_t i_mode, mask, perm; 63 64 i_mode = inode->i_mode; 65 66 mask = (S_ISREG(i_mode) || S_ISLNK(i_mode)) ? 67 sbi->options.fs_fmask : sbi->options.fs_dmask; 68 perm = *mode_ptr & ~(S_IFMT | mask); 69 70 /* Of the r and x bits, all (subject to umask) must be present.*/ 71 if ((perm & 0555) != (i_mode & 0555)) 72 return -EPERM; 73 74 if (exfat_mode_can_hold_ro(inode)) { 75 /* 76 * Of the w bits, either all (subject to umask) or none must 77 * be present. 78 */ 79 if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask))) 80 return -EPERM; 81 } else { 82 /* 83 * If exfat_mode_can_hold_ro(inode) is false, can't change 84 * w bits. 85 */ 86 if ((perm & 0222) != (0222 & ~mask)) 87 return -EPERM; 88 } 89 90 *mode_ptr &= S_IFMT | perm; 91 92 return 0; 93 } 94 95 /* resize the file length */ 96 int __exfat_truncate(struct inode *inode, loff_t new_size) 97 { 98 unsigned int num_clusters_new, num_clusters_phys; 99 unsigned int last_clu = EXFAT_FREE_CLUSTER; 100 struct exfat_chain clu; 101 struct super_block *sb = inode->i_sb; 102 struct exfat_sb_info *sbi = EXFAT_SB(sb); 103 struct exfat_inode_info *ei = EXFAT_I(inode); 104 105 /* check if the given file ID is opened */ 106 if (ei->type != TYPE_FILE && ei->type != TYPE_DIR) 107 return -EPERM; 108 109 exfat_set_volume_dirty(sb); 110 111 num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi); 112 num_clusters_phys = EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi); 113 114 exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags); 115 116 if (new_size > 0) { 117 /* 118 * Truncate FAT chain num_clusters after the first cluster 119 * num_clusters = min(new, phys); 120 */ 121 unsigned int num_clusters = 122 min(num_clusters_new, num_clusters_phys); 123 124 /* 125 * Follow FAT chain 126 * (defensive coding - works fine even with corrupted FAT table 127 */ 128 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 129 clu.dir += num_clusters; 130 clu.size -= num_clusters; 131 } else { 132 while (num_clusters > 0) { 133 last_clu = clu.dir; 134 if (exfat_get_next_cluster(sb, &(clu.dir))) 135 return -EIO; 136 137 num_clusters--; 138 clu.size--; 139 } 140 } 141 } else { 142 ei->flags = ALLOC_NO_FAT_CHAIN; 143 ei->start_clu = EXFAT_EOF_CLUSTER; 144 } 145 146 i_size_write(inode, new_size); 147 148 if (ei->type == TYPE_FILE) 149 ei->attr |= ATTR_ARCHIVE; 150 151 /* 152 * update the directory entry 153 * 154 * If the directory entry is updated by mark_inode_dirty(), the 155 * directory entry will be written after a writeback cycle of 156 * updating the bitmap/FAT, which may result in clusters being 157 * freed but referenced by the directory entry in the event of a 158 * sudden power failure. 159 * __exfat_write_inode() is called for directory entry, bitmap 160 * and FAT to be written in a same writeback. 161 */ 162 if (__exfat_write_inode(inode, inode_needs_sync(inode))) 163 return -EIO; 164 165 /* cut off from the FAT chain */ 166 if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER && 167 last_clu != EXFAT_EOF_CLUSTER) { 168 if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER)) 169 return -EIO; 170 } 171 172 /* invalidate cache and free the clusters */ 173 /* clear exfat cache */ 174 exfat_cache_inval_inode(inode); 175 176 /* hint information */ 177 ei->hint_bmap.off = EXFAT_EOF_CLUSTER; 178 ei->hint_bmap.clu = EXFAT_EOF_CLUSTER; 179 180 /* hint_stat will be used if this is directory. */ 181 ei->hint_stat.eidx = 0; 182 ei->hint_stat.clu = ei->start_clu; 183 ei->hint_femp.eidx = EXFAT_HINT_NONE; 184 185 /* free the clusters */ 186 if (exfat_free_cluster(inode, &clu)) 187 return -EIO; 188 189 return 0; 190 } 191 192 void exfat_truncate(struct inode *inode, loff_t size) 193 { 194 struct super_block *sb = inode->i_sb; 195 struct exfat_sb_info *sbi = EXFAT_SB(sb); 196 struct exfat_inode_info *ei = EXFAT_I(inode); 197 unsigned int blocksize = i_blocksize(inode); 198 loff_t aligned_size; 199 int err; 200 201 mutex_lock(&sbi->s_lock); 202 if (ei->start_clu == 0) { 203 /* 204 * Empty start_clu != ~0 (not allocated) 205 */ 206 exfat_fs_error(sb, "tried to truncate zeroed cluster."); 207 goto write_size; 208 } 209 210 err = __exfat_truncate(inode, i_size_read(inode)); 211 if (err) 212 goto write_size; 213 214 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 215 inode->i_blkbits; 216 write_size: 217 aligned_size = i_size_read(inode); 218 if (aligned_size & (blocksize - 1)) { 219 aligned_size |= (blocksize - 1); 220 aligned_size++; 221 } 222 223 if (ei->i_size_ondisk > i_size_read(inode)) 224 ei->i_size_ondisk = aligned_size; 225 226 if (ei->i_size_aligned > i_size_read(inode)) 227 ei->i_size_aligned = aligned_size; 228 mutex_unlock(&sbi->s_lock); 229 } 230 231 int exfat_getattr(struct user_namespace *mnt_uerns, const struct path *path, 232 struct kstat *stat, unsigned int request_mask, 233 unsigned int query_flags) 234 { 235 struct inode *inode = d_backing_inode(path->dentry); 236 struct exfat_inode_info *ei = EXFAT_I(inode); 237 238 generic_fillattr(&init_user_ns, inode, stat); 239 exfat_truncate_atime(&stat->atime); 240 stat->result_mask |= STATX_BTIME; 241 stat->btime.tv_sec = ei->i_crtime.tv_sec; 242 stat->btime.tv_nsec = ei->i_crtime.tv_nsec; 243 stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size; 244 return 0; 245 } 246 247 int exfat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, 248 struct iattr *attr) 249 { 250 struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb); 251 struct inode *inode = dentry->d_inode; 252 unsigned int ia_valid; 253 int error; 254 255 if ((attr->ia_valid & ATTR_SIZE) && 256 attr->ia_size > i_size_read(inode)) { 257 error = exfat_cont_expand(inode, attr->ia_size); 258 if (error || attr->ia_valid == ATTR_SIZE) 259 return error; 260 attr->ia_valid &= ~ATTR_SIZE; 261 } 262 263 /* Check for setting the inode time. */ 264 ia_valid = attr->ia_valid; 265 if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) && 266 exfat_allow_set_time(sbi, inode)) { 267 attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET | 268 ATTR_TIMES_SET); 269 } 270 271 error = setattr_prepare(&init_user_ns, dentry, attr); 272 attr->ia_valid = ia_valid; 273 if (error) 274 goto out; 275 276 if (((attr->ia_valid & ATTR_UID) && 277 !uid_eq(attr->ia_uid, sbi->options.fs_uid)) || 278 ((attr->ia_valid & ATTR_GID) && 279 !gid_eq(attr->ia_gid, sbi->options.fs_gid)) || 280 ((attr->ia_valid & ATTR_MODE) && 281 (attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) { 282 error = -EPERM; 283 goto out; 284 } 285 286 /* 287 * We don't return -EPERM here. Yes, strange, but this is too 288 * old behavior. 289 */ 290 if (attr->ia_valid & ATTR_MODE) { 291 if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0) 292 attr->ia_valid &= ~ATTR_MODE; 293 } 294 295 if (attr->ia_valid & ATTR_SIZE) 296 inode->i_mtime = inode->i_ctime = current_time(inode); 297 298 setattr_copy(&init_user_ns, inode, attr); 299 exfat_truncate_atime(&inode->i_atime); 300 301 if (attr->ia_valid & ATTR_SIZE) { 302 error = exfat_block_truncate_page(inode, attr->ia_size); 303 if (error) 304 goto out; 305 306 down_write(&EXFAT_I(inode)->truncate_lock); 307 truncate_setsize(inode, attr->ia_size); 308 309 /* 310 * __exfat_write_inode() is called from exfat_truncate(), inode 311 * is already written by it, so mark_inode_dirty() is unneeded. 312 */ 313 exfat_truncate(inode, attr->ia_size); 314 up_write(&EXFAT_I(inode)->truncate_lock); 315 } else 316 mark_inode_dirty(inode); 317 318 out: 319 return error; 320 } 321 322 static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg) 323 { 324 struct fstrim_range range; 325 int ret = 0; 326 327 if (!capable(CAP_SYS_ADMIN)) 328 return -EPERM; 329 330 if (!bdev_max_discard_sectors(inode->i_sb->s_bdev)) 331 return -EOPNOTSUPP; 332 333 if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range))) 334 return -EFAULT; 335 336 range.minlen = max_t(unsigned int, range.minlen, 337 bdev_discard_granularity(inode->i_sb->s_bdev)); 338 339 ret = exfat_trim_fs(inode, &range); 340 if (ret < 0) 341 return ret; 342 343 if (copy_to_user((struct fstrim_range __user *)arg, &range, sizeof(range))) 344 return -EFAULT; 345 346 return 0; 347 } 348 349 long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 350 { 351 struct inode *inode = file_inode(filp); 352 353 switch (cmd) { 354 case FITRIM: 355 return exfat_ioctl_fitrim(inode, arg); 356 default: 357 return -ENOTTY; 358 } 359 } 360 361 #ifdef CONFIG_COMPAT 362 long exfat_compat_ioctl(struct file *filp, unsigned int cmd, 363 unsigned long arg) 364 { 365 return exfat_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); 366 } 367 #endif 368 369 int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync) 370 { 371 struct inode *inode = filp->f_mapping->host; 372 int err; 373 374 err = __generic_file_fsync(filp, start, end, datasync); 375 if (err) 376 return err; 377 378 err = sync_blockdev(inode->i_sb->s_bdev); 379 if (err) 380 return err; 381 382 return blkdev_issue_flush(inode->i_sb->s_bdev); 383 } 384 385 const struct file_operations exfat_file_operations = { 386 .llseek = generic_file_llseek, 387 .read_iter = generic_file_read_iter, 388 .write_iter = generic_file_write_iter, 389 .unlocked_ioctl = exfat_ioctl, 390 #ifdef CONFIG_COMPAT 391 .compat_ioctl = exfat_compat_ioctl, 392 #endif 393 .mmap = generic_file_mmap, 394 .fsync = exfat_file_fsync, 395 .splice_read = generic_file_splice_read, 396 .splice_write = iter_file_splice_write, 397 }; 398 399 const struct inode_operations exfat_file_inode_operations = { 400 .setattr = exfat_setattr, 401 .getattr = exfat_getattr, 402 }; 403