1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Interface between ext4 and JBD 4 */ 5 6 #include "ext4_jbd2.h" 7 8 #include <trace/events/ext4.h> 9 10 int ext4_inode_journal_mode(struct inode *inode) 11 { 12 if (EXT4_JOURNAL(inode) == NULL) 13 return EXT4_INODE_WRITEBACK_DATA_MODE; /* writeback */ 14 /* We do not support data journalling with delayed allocation */ 15 if (!S_ISREG(inode->i_mode) || 16 ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE) || 17 test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA || 18 (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA) && 19 !test_opt(inode->i_sb, DELALLOC))) { 20 /* We do not support data journalling for encrypted data */ 21 if (S_ISREG(inode->i_mode) && IS_ENCRYPTED(inode)) 22 return EXT4_INODE_ORDERED_DATA_MODE; /* ordered */ 23 return EXT4_INODE_JOURNAL_DATA_MODE; /* journal data */ 24 } 25 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) 26 return EXT4_INODE_ORDERED_DATA_MODE; /* ordered */ 27 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA) 28 return EXT4_INODE_WRITEBACK_DATA_MODE; /* writeback */ 29 BUG(); 30 } 31 32 /* Just increment the non-pointer handle value */ 33 static handle_t *ext4_get_nojournal(void) 34 { 35 handle_t *handle = current->journal_info; 36 37 BUG_ON(handle && !handle->h_invalid); 38 39 if (!handle) { 40 handle = jbd2_alloc_handle(GFP_NOFS); 41 if (!handle) 42 return ERR_PTR(-ENOMEM); 43 handle->h_invalid = 1; 44 /* 45 * This is done by start_this_handle() if journalling 46 * is enabled. 47 */ 48 handle->saved_alloc_context = memalloc_nofs_save(); 49 current->journal_info = handle; 50 } 51 handle->h_ref++; 52 return handle; 53 } 54 55 56 /* Decrement the non-pointer handle value */ 57 static void ext4_put_nojournal(handle_t *handle) 58 { 59 BUG_ON(handle->h_ref == 0); 60 61 handle->h_ref--; 62 if (handle->h_ref == 0) { 63 memalloc_nofs_restore(handle->saved_alloc_context); 64 jbd2_free_handle(handle); 65 current->journal_info = NULL; 66 } 67 } 68 69 /* 70 * Wrappers for jbd2_journal_start/end. 71 */ 72 static int ext4_journal_check_start(struct super_block *sb) 73 { 74 int ret; 75 journal_t *journal; 76 77 might_sleep(); 78 79 ret = ext4_emergency_state(sb); 80 if (unlikely(ret)) 81 return ret; 82 83 if (WARN_ON_ONCE(sb_rdonly(sb))) 84 return -EROFS; 85 86 WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE); 87 journal = EXT4_SB(sb)->s_journal; 88 /* 89 * Special case here: if the journal has aborted behind our 90 * backs (eg. EIO in the commit thread), then we still need to 91 * take the FS itself readonly cleanly. 92 */ 93 if (journal && is_journal_aborted(journal)) { 94 ext4_abort(sb, -journal->j_errno, "Detected aborted journal"); 95 return -EROFS; 96 } 97 return 0; 98 } 99 100 handle_t *__ext4_journal_start_sb(struct inode *inode, 101 struct super_block *sb, unsigned int line, 102 int type, int blocks, int rsv_blocks, 103 int revoke_creds) 104 { 105 journal_t *journal; 106 int err; 107 if (inode) 108 trace_ext4_journal_start_inode(inode, blocks, rsv_blocks, 109 revoke_creds, type, 110 _RET_IP_); 111 else 112 trace_ext4_journal_start_sb(sb, blocks, rsv_blocks, 113 revoke_creds, type, 114 _RET_IP_); 115 err = ext4_journal_check_start(sb); 116 if (err < 0) 117 return ERR_PTR(err); 118 119 journal = EXT4_SB(sb)->s_journal; 120 if (!journal || (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)) 121 return ext4_get_nojournal(); 122 return jbd2__journal_start(journal, blocks, rsv_blocks, revoke_creds, 123 GFP_NOFS, type, line); 124 } 125 126 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle) 127 { 128 struct super_block *sb; 129 int err; 130 int rc; 131 132 if (!ext4_handle_valid(handle)) { 133 ext4_put_nojournal(handle); 134 return 0; 135 } 136 137 err = handle->h_err; 138 if (!handle->h_transaction) { 139 rc = jbd2_journal_stop(handle); 140 return err ? err : rc; 141 } 142 143 sb = handle->h_transaction->t_journal->j_private; 144 rc = jbd2_journal_stop(handle); 145 146 if (!err) 147 err = rc; 148 if (err) 149 __ext4_std_error(sb, where, line, err); 150 return err; 151 } 152 153 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line, 154 int type) 155 { 156 struct super_block *sb; 157 int err; 158 159 if (!ext4_handle_valid(handle)) 160 return ext4_get_nojournal(); 161 162 sb = handle->h_journal->j_private; 163 trace_ext4_journal_start_reserved(sb, 164 jbd2_handle_buffer_credits(handle), _RET_IP_); 165 err = ext4_journal_check_start(sb); 166 if (err < 0) { 167 jbd2_journal_free_reserved(handle); 168 return ERR_PTR(err); 169 } 170 171 err = jbd2_journal_start_reserved(handle, type, line); 172 if (err < 0) 173 return ERR_PTR(err); 174 return handle; 175 } 176 177 int __ext4_journal_ensure_credits(handle_t *handle, int check_cred, 178 int extend_cred, int revoke_cred) 179 { 180 if (!ext4_handle_valid(handle)) 181 return 0; 182 if (is_handle_aborted(handle)) 183 return -EROFS; 184 if (jbd2_handle_buffer_credits(handle) >= check_cred && 185 handle->h_revoke_credits >= revoke_cred) 186 return 0; 187 extend_cred = max(0, extend_cred - jbd2_handle_buffer_credits(handle)); 188 revoke_cred = max(0, revoke_cred - handle->h_revoke_credits); 189 return ext4_journal_extend(handle, extend_cred, revoke_cred); 190 } 191 192 static void ext4_journal_abort_handle(const char *caller, unsigned int line, 193 const char *err_fn, 194 struct buffer_head *bh, 195 handle_t *handle, int err) 196 { 197 char nbuf[16]; 198 const char *errstr = ext4_decode_error(NULL, err, nbuf); 199 200 BUG_ON(!ext4_handle_valid(handle)); 201 202 if (bh) 203 BUFFER_TRACE(bh, "abort"); 204 205 if (!handle->h_err) 206 handle->h_err = err; 207 208 if (is_handle_aborted(handle)) 209 return; 210 211 printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n", 212 caller, line, errstr, err_fn); 213 214 jbd2_journal_abort_handle(handle); 215 } 216 217 static void ext4_check_bdev_write_error(struct super_block *sb) 218 { 219 struct address_space *mapping = sb->s_bdev->bd_mapping; 220 struct ext4_sb_info *sbi = EXT4_SB(sb); 221 int err; 222 223 /* 224 * If the block device has write error flag, it may have failed to 225 * async write out metadata buffers in the background. In this case, 226 * we could read old data from disk and write it out again, which 227 * may lead to on-disk filesystem inconsistency. 228 */ 229 if (errseq_check(&mapping->wb_err, READ_ONCE(sbi->s_bdev_wb_err))) { 230 spin_lock(&sbi->s_bdev_wb_lock); 231 err = errseq_check_and_advance(&mapping->wb_err, &sbi->s_bdev_wb_err); 232 spin_unlock(&sbi->s_bdev_wb_lock); 233 if (err) 234 ext4_error_err(sb, -err, 235 "Error while async write back metadata"); 236 } 237 } 238 239 int __ext4_journal_get_write_access(const char *where, unsigned int line, 240 handle_t *handle, struct super_block *sb, 241 struct buffer_head *bh, 242 enum ext4_journal_trigger_type trigger_type) 243 { 244 int err; 245 246 might_sleep(); 247 248 if (ext4_handle_valid(handle)) { 249 err = jbd2_journal_get_write_access(handle, bh); 250 if (err) { 251 ext4_journal_abort_handle(where, line, __func__, bh, 252 handle, err); 253 return err; 254 } 255 } else 256 ext4_check_bdev_write_error(sb); 257 if (trigger_type == EXT4_JTR_NONE || 258 !ext4_has_feature_metadata_csum(sb)) 259 return 0; 260 BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT); 261 jbd2_journal_set_triggers(bh, 262 &EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers); 263 return 0; 264 } 265 266 /* 267 * The ext4 forget function must perform a revoke if we are freeing data 268 * which has been journaled. Metadata (eg. indirect blocks) must be 269 * revoked in all cases. 270 * 271 * "bh" may be NULL: a metadata block may have been freed from memory 272 * but there may still be a record of it in the journal, and that record 273 * still needs to be revoked. 274 */ 275 int __ext4_forget(const char *where, unsigned int line, handle_t *handle, 276 int is_metadata, struct inode *inode, 277 struct buffer_head *bh, ext4_fsblk_t blocknr) 278 { 279 int err; 280 281 might_sleep(); 282 283 trace_ext4_forget(inode, is_metadata, blocknr); 284 BUFFER_TRACE(bh, "enter"); 285 286 ext4_debug("forgetting bh %p: is_metadata=%d, mode %o, data mode %x\n", 287 bh, is_metadata, inode->i_mode, 288 test_opt(inode->i_sb, DATA_FLAGS)); 289 290 /* 291 * In the no journal case, we should wait for the ongoing buffer 292 * to complete and do a forget. 293 */ 294 if (!ext4_handle_valid(handle)) { 295 if (bh) { 296 clear_buffer_dirty(bh); 297 wait_on_buffer(bh); 298 __bforget(bh); 299 } 300 return 0; 301 } 302 303 /* Never use the revoke function if we are doing full data 304 * journaling: there is no need to, and a V1 superblock won't 305 * support it. Otherwise, only skip the revoke on un-journaled 306 * data blocks. */ 307 308 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA || 309 (!is_metadata && !ext4_should_journal_data(inode))) { 310 if (bh) { 311 BUFFER_TRACE(bh, "call jbd2_journal_forget"); 312 err = jbd2_journal_forget(handle, bh); 313 if (err) 314 ext4_journal_abort_handle(where, line, __func__, 315 bh, handle, err); 316 return err; 317 } 318 return 0; 319 } 320 321 /* 322 * data!=journal && (is_metadata || should_journal_data(inode)) 323 */ 324 BUFFER_TRACE(bh, "call jbd2_journal_revoke"); 325 err = jbd2_journal_revoke(handle, blocknr, bh); 326 if (err) { 327 ext4_journal_abort_handle(where, line, __func__, 328 bh, handle, err); 329 __ext4_error(inode->i_sb, where, line, true, -err, 0, 330 "error %d when attempting revoke", err); 331 } 332 BUFFER_TRACE(bh, "exit"); 333 return err; 334 } 335 336 int __ext4_journal_get_create_access(const char *where, unsigned int line, 337 handle_t *handle, struct super_block *sb, 338 struct buffer_head *bh, 339 enum ext4_journal_trigger_type trigger_type) 340 { 341 int err; 342 343 if (!ext4_handle_valid(handle)) 344 return 0; 345 346 err = jbd2_journal_get_create_access(handle, bh); 347 if (err) { 348 ext4_journal_abort_handle(where, line, __func__, bh, handle, 349 err); 350 return err; 351 } 352 if (trigger_type == EXT4_JTR_NONE || 353 !ext4_has_feature_metadata_csum(sb)) 354 return 0; 355 BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT); 356 jbd2_journal_set_triggers(bh, 357 &EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers); 358 return 0; 359 } 360 361 static void ext4_inode_attach_mmb(struct inode *inode) 362 { 363 struct mapping_metadata_bhs *mmb; 364 365 /* 366 * It's difficult to handle failure when marking buffer dirty without 367 * leaving filesystem corrupted 368 */ 369 mmb = kmalloc_obj(*mmb, GFP_NOFS | __GFP_NOFAIL | __GFP_ACCOUNT); 370 mmb_init(mmb, &inode->i_data); 371 /* Someone swapped another mmb before us? */ 372 if (cmpxchg(&EXT4_I(inode)->i_metadata_bhs, NULL, mmb)) 373 kfree(mmb); 374 } 375 376 int __ext4_handle_dirty_metadata(const char *where, unsigned int line, 377 handle_t *handle, struct inode *inode, 378 struct buffer_head *bh) 379 { 380 int err = 0; 381 382 might_sleep(); 383 384 set_buffer_meta(bh); 385 set_buffer_prio(bh); 386 set_buffer_uptodate(bh); 387 if (ext4_handle_valid(handle)) { 388 err = jbd2_journal_dirty_metadata(handle, bh); 389 /* Errors can only happen due to aborted journal or a nasty bug */ 390 if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) { 391 ext4_journal_abort_handle(where, line, __func__, bh, 392 handle, err); 393 if (inode == NULL) { 394 pr_err("EXT4: jbd2_journal_dirty_metadata " 395 "failed: handle type %u started at " 396 "line %u, credits %u/%u, errcode %d", 397 handle->h_type, 398 handle->h_line_no, 399 handle->h_requested_credits, 400 jbd2_handle_buffer_credits(handle), err); 401 return err; 402 } 403 ext4_error_inode(inode, where, line, 404 bh->b_blocknr, 405 "journal_dirty_metadata failed: " 406 "handle type %u started at line %u, " 407 "credits %u/%u, errcode %d", 408 handle->h_type, 409 handle->h_line_no, 410 handle->h_requested_credits, 411 jbd2_handle_buffer_credits(handle), 412 err); 413 } 414 } else { 415 if (inode) { 416 if (!ext4_i_metadata_bhs(inode)) 417 ext4_inode_attach_mmb(inode); 418 mmb_mark_buffer_dirty(bh, ext4_i_metadata_bhs(inode)); 419 } else { 420 mark_buffer_dirty(bh); 421 } 422 if (inode && inode_needs_sync(inode)) { 423 sync_dirty_buffer(bh); 424 if (buffer_req(bh) && !buffer_uptodate(bh)) { 425 ext4_error_inode_err(inode, where, line, 426 bh->b_blocknr, EIO, 427 "IO error syncing itable block"); 428 err = -EIO; 429 } 430 } 431 } 432 return err; 433 } 434