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 unsigned long ref_cnt = (unsigned long)handle; 37 38 BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT); 39 40 ref_cnt++; 41 handle = (handle_t *)ref_cnt; 42 43 current->journal_info = handle; 44 return handle; 45 } 46 47 48 /* Decrement the non-pointer handle value */ 49 static void ext4_put_nojournal(handle_t *handle) 50 { 51 unsigned long ref_cnt = (unsigned long)handle; 52 53 BUG_ON(ref_cnt == 0); 54 55 ref_cnt--; 56 handle = (handle_t *)ref_cnt; 57 58 current->journal_info = handle; 59 } 60 61 /* 62 * Wrappers for jbd2_journal_start/end. 63 */ 64 static int ext4_journal_check_start(struct super_block *sb) 65 { 66 journal_t *journal; 67 68 might_sleep(); 69 70 if (unlikely(ext4_forced_shutdown(EXT4_SB(sb)))) 71 return -EIO; 72 73 if (sb_rdonly(sb)) 74 return -EROFS; 75 WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE); 76 journal = EXT4_SB(sb)->s_journal; 77 /* 78 * Special case here: if the journal has aborted behind our 79 * backs (eg. EIO in the commit thread), then we still need to 80 * take the FS itself readonly cleanly. 81 */ 82 if (journal && is_journal_aborted(journal)) { 83 ext4_abort(sb, -journal->j_errno, "Detected aborted journal"); 84 return -EROFS; 85 } 86 return 0; 87 } 88 89 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line, 90 int type, int blocks, int rsv_blocks, 91 int revoke_creds) 92 { 93 journal_t *journal; 94 int err; 95 96 trace_ext4_journal_start(sb, blocks, rsv_blocks, revoke_creds, 97 _RET_IP_); 98 err = ext4_journal_check_start(sb); 99 if (err < 0) 100 return ERR_PTR(err); 101 102 journal = EXT4_SB(sb)->s_journal; 103 if (!journal || (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)) 104 return ext4_get_nojournal(); 105 return jbd2__journal_start(journal, blocks, rsv_blocks, revoke_creds, 106 GFP_NOFS, type, line); 107 } 108 109 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle) 110 { 111 struct super_block *sb; 112 int err; 113 int rc; 114 115 if (!ext4_handle_valid(handle)) { 116 ext4_put_nojournal(handle); 117 return 0; 118 } 119 120 err = handle->h_err; 121 if (!handle->h_transaction) { 122 rc = jbd2_journal_stop(handle); 123 return err ? err : rc; 124 } 125 126 sb = handle->h_transaction->t_journal->j_private; 127 rc = jbd2_journal_stop(handle); 128 129 if (!err) 130 err = rc; 131 if (err) 132 __ext4_std_error(sb, where, line, err); 133 return err; 134 } 135 136 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line, 137 int type) 138 { 139 struct super_block *sb; 140 int err; 141 142 if (!ext4_handle_valid(handle)) 143 return ext4_get_nojournal(); 144 145 sb = handle->h_journal->j_private; 146 trace_ext4_journal_start_reserved(sb, 147 jbd2_handle_buffer_credits(handle), _RET_IP_); 148 err = ext4_journal_check_start(sb); 149 if (err < 0) { 150 jbd2_journal_free_reserved(handle); 151 return ERR_PTR(err); 152 } 153 154 err = jbd2_journal_start_reserved(handle, type, line); 155 if (err < 0) 156 return ERR_PTR(err); 157 return handle; 158 } 159 160 int __ext4_journal_ensure_credits(handle_t *handle, int check_cred, 161 int extend_cred, int revoke_cred) 162 { 163 if (!ext4_handle_valid(handle)) 164 return 0; 165 if (jbd2_handle_buffer_credits(handle) >= check_cred && 166 handle->h_revoke_credits >= revoke_cred) 167 return 0; 168 extend_cred = max(0, extend_cred - jbd2_handle_buffer_credits(handle)); 169 revoke_cred = max(0, revoke_cred - handle->h_revoke_credits); 170 return ext4_journal_extend(handle, extend_cred, revoke_cred); 171 } 172 173 static void ext4_journal_abort_handle(const char *caller, unsigned int line, 174 const char *err_fn, 175 struct buffer_head *bh, 176 handle_t *handle, int err) 177 { 178 char nbuf[16]; 179 const char *errstr = ext4_decode_error(NULL, err, nbuf); 180 181 BUG_ON(!ext4_handle_valid(handle)); 182 183 if (bh) 184 BUFFER_TRACE(bh, "abort"); 185 186 if (!handle->h_err) 187 handle->h_err = err; 188 189 if (is_handle_aborted(handle)) 190 return; 191 192 printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n", 193 caller, line, errstr, err_fn); 194 195 jbd2_journal_abort_handle(handle); 196 } 197 198 static void ext4_check_bdev_write_error(struct super_block *sb) 199 { 200 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; 201 struct ext4_sb_info *sbi = EXT4_SB(sb); 202 int err; 203 204 /* 205 * If the block device has write error flag, it may have failed to 206 * async write out metadata buffers in the background. In this case, 207 * we could read old data from disk and write it out again, which 208 * may lead to on-disk filesystem inconsistency. 209 */ 210 if (errseq_check(&mapping->wb_err, READ_ONCE(sbi->s_bdev_wb_err))) { 211 spin_lock(&sbi->s_bdev_wb_lock); 212 err = errseq_check_and_advance(&mapping->wb_err, &sbi->s_bdev_wb_err); 213 spin_unlock(&sbi->s_bdev_wb_lock); 214 if (err) 215 ext4_error_err(sb, -err, 216 "Error while async write back metadata"); 217 } 218 } 219 220 int __ext4_journal_get_write_access(const char *where, unsigned int line, 221 handle_t *handle, struct buffer_head *bh) 222 { 223 int err = 0; 224 225 might_sleep(); 226 227 if (bh->b_bdev->bd_super) 228 ext4_check_bdev_write_error(bh->b_bdev->bd_super); 229 230 if (ext4_handle_valid(handle)) { 231 err = jbd2_journal_get_write_access(handle, bh); 232 if (err) 233 ext4_journal_abort_handle(where, line, __func__, bh, 234 handle, err); 235 } 236 return err; 237 } 238 239 /* 240 * The ext4 forget function must perform a revoke if we are freeing data 241 * which has been journaled. Metadata (eg. indirect blocks) must be 242 * revoked in all cases. 243 * 244 * "bh" may be NULL: a metadata block may have been freed from memory 245 * but there may still be a record of it in the journal, and that record 246 * still needs to be revoked. 247 * 248 * If the handle isn't valid we're not journaling, but we still need to 249 * call into ext4_journal_revoke() to put the buffer head. 250 */ 251 int __ext4_forget(const char *where, unsigned int line, handle_t *handle, 252 int is_metadata, struct inode *inode, 253 struct buffer_head *bh, ext4_fsblk_t blocknr) 254 { 255 int err; 256 257 might_sleep(); 258 259 trace_ext4_forget(inode, is_metadata, blocknr); 260 BUFFER_TRACE(bh, "enter"); 261 262 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, " 263 "data mode %x\n", 264 bh, is_metadata, inode->i_mode, 265 test_opt(inode->i_sb, DATA_FLAGS)); 266 267 /* In the no journal case, we can just do a bforget and return */ 268 if (!ext4_handle_valid(handle)) { 269 bforget(bh); 270 return 0; 271 } 272 273 /* Never use the revoke function if we are doing full data 274 * journaling: there is no need to, and a V1 superblock won't 275 * support it. Otherwise, only skip the revoke on un-journaled 276 * data blocks. */ 277 278 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA || 279 (!is_metadata && !ext4_should_journal_data(inode))) { 280 if (bh) { 281 BUFFER_TRACE(bh, "call jbd2_journal_forget"); 282 err = jbd2_journal_forget(handle, bh); 283 if (err) 284 ext4_journal_abort_handle(where, line, __func__, 285 bh, handle, err); 286 return err; 287 } 288 return 0; 289 } 290 291 /* 292 * data!=journal && (is_metadata || should_journal_data(inode)) 293 */ 294 BUFFER_TRACE(bh, "call jbd2_journal_revoke"); 295 err = jbd2_journal_revoke(handle, blocknr, bh); 296 if (err) { 297 ext4_journal_abort_handle(where, line, __func__, 298 bh, handle, err); 299 __ext4_error(inode->i_sb, where, line, true, -err, 0, 300 "error %d when attempting revoke", err); 301 } 302 BUFFER_TRACE(bh, "exit"); 303 return err; 304 } 305 306 int __ext4_journal_get_create_access(const char *where, unsigned int line, 307 handle_t *handle, struct buffer_head *bh) 308 { 309 int err = 0; 310 311 if (ext4_handle_valid(handle)) { 312 err = jbd2_journal_get_create_access(handle, bh); 313 if (err) 314 ext4_journal_abort_handle(where, line, __func__, 315 bh, handle, err); 316 } 317 return err; 318 } 319 320 int __ext4_handle_dirty_metadata(const char *where, unsigned int line, 321 handle_t *handle, struct inode *inode, 322 struct buffer_head *bh) 323 { 324 int err = 0; 325 326 might_sleep(); 327 328 set_buffer_meta(bh); 329 set_buffer_prio(bh); 330 set_buffer_uptodate(bh); 331 if (ext4_handle_valid(handle)) { 332 err = jbd2_journal_dirty_metadata(handle, bh); 333 /* Errors can only happen due to aborted journal or a nasty bug */ 334 if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) { 335 ext4_journal_abort_handle(where, line, __func__, bh, 336 handle, err); 337 if (inode == NULL) { 338 pr_err("EXT4: jbd2_journal_dirty_metadata " 339 "failed: handle type %u started at " 340 "line %u, credits %u/%u, errcode %d", 341 handle->h_type, 342 handle->h_line_no, 343 handle->h_requested_credits, 344 jbd2_handle_buffer_credits(handle), err); 345 return err; 346 } 347 ext4_error_inode(inode, where, line, 348 bh->b_blocknr, 349 "journal_dirty_metadata failed: " 350 "handle type %u started at line %u, " 351 "credits %u/%u, errcode %d", 352 handle->h_type, 353 handle->h_line_no, 354 handle->h_requested_credits, 355 jbd2_handle_buffer_credits(handle), 356 err); 357 } 358 } else { 359 if (inode) 360 mark_buffer_dirty_inode(bh, inode); 361 else 362 mark_buffer_dirty(bh); 363 if (inode && inode_needs_sync(inode)) { 364 sync_dirty_buffer(bh); 365 if (buffer_req(bh) && !buffer_uptodate(bh)) { 366 ext4_error_inode_err(inode, where, line, 367 bh->b_blocknr, EIO, 368 "IO error syncing itable block"); 369 err = -EIO; 370 } 371 } 372 } 373 return err; 374 } 375