1 /* 2 * Interface between ext4 and JBD 3 */ 4 5 #include "ext4_jbd2.h" 6 7 #include <trace/events/ext4.h> 8 9 /* Just increment the non-pointer handle value */ 10 static handle_t *ext4_get_nojournal(void) 11 { 12 handle_t *handle = current->journal_info; 13 unsigned long ref_cnt = (unsigned long)handle; 14 15 BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT); 16 17 ref_cnt++; 18 handle = (handle_t *)ref_cnt; 19 20 current->journal_info = handle; 21 return handle; 22 } 23 24 25 /* Decrement the non-pointer handle value */ 26 static void ext4_put_nojournal(handle_t *handle) 27 { 28 unsigned long ref_cnt = (unsigned long)handle; 29 30 BUG_ON(ref_cnt == 0); 31 32 ref_cnt--; 33 handle = (handle_t *)ref_cnt; 34 35 current->journal_info = handle; 36 } 37 38 /* 39 * Wrappers for jbd2_journal_start/end. 40 */ 41 static int ext4_journal_check_start(struct super_block *sb) 42 { 43 journal_t *journal; 44 45 might_sleep(); 46 if (sb->s_flags & MS_RDONLY) 47 return -EROFS; 48 WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE); 49 journal = EXT4_SB(sb)->s_journal; 50 /* 51 * Special case here: if the journal has aborted behind our 52 * backs (eg. EIO in the commit thread), then we still need to 53 * take the FS itself readonly cleanly. 54 */ 55 if (journal && is_journal_aborted(journal)) { 56 ext4_abort(sb, "Detected aborted journal"); 57 return -EROFS; 58 } 59 return 0; 60 } 61 62 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line, 63 int type, int blocks, int rsv_blocks) 64 { 65 journal_t *journal; 66 int err; 67 68 trace_ext4_journal_start(sb, blocks, rsv_blocks, _RET_IP_); 69 err = ext4_journal_check_start(sb); 70 if (err < 0) 71 return ERR_PTR(err); 72 73 journal = EXT4_SB(sb)->s_journal; 74 if (!journal) 75 return ext4_get_nojournal(); 76 return jbd2__journal_start(journal, blocks, rsv_blocks, GFP_NOFS, 77 type, line); 78 } 79 80 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle) 81 { 82 struct super_block *sb; 83 int err; 84 int rc; 85 86 if (!ext4_handle_valid(handle)) { 87 ext4_put_nojournal(handle); 88 return 0; 89 } 90 sb = handle->h_transaction->t_journal->j_private; 91 err = handle->h_err; 92 rc = jbd2_journal_stop(handle); 93 94 if (!err) 95 err = rc; 96 if (err) 97 __ext4_std_error(sb, where, line, err); 98 return err; 99 } 100 101 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line, 102 int type) 103 { 104 struct super_block *sb; 105 int err; 106 107 if (!ext4_handle_valid(handle)) 108 return ext4_get_nojournal(); 109 110 sb = handle->h_journal->j_private; 111 trace_ext4_journal_start_reserved(sb, handle->h_buffer_credits, 112 _RET_IP_); 113 err = ext4_journal_check_start(sb); 114 if (err < 0) { 115 jbd2_journal_free_reserved(handle); 116 return ERR_PTR(err); 117 } 118 119 err = jbd2_journal_start_reserved(handle, type, line); 120 if (err < 0) 121 return ERR_PTR(err); 122 return handle; 123 } 124 125 static void ext4_journal_abort_handle(const char *caller, unsigned int line, 126 const char *err_fn, 127 struct buffer_head *bh, 128 handle_t *handle, int err) 129 { 130 char nbuf[16]; 131 const char *errstr = ext4_decode_error(NULL, err, nbuf); 132 133 BUG_ON(!ext4_handle_valid(handle)); 134 135 if (bh) 136 BUFFER_TRACE(bh, "abort"); 137 138 if (!handle->h_err) 139 handle->h_err = err; 140 141 if (is_handle_aborted(handle)) 142 return; 143 144 printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n", 145 caller, line, errstr, err_fn); 146 147 jbd2_journal_abort_handle(handle); 148 } 149 150 int __ext4_journal_get_write_access(const char *where, unsigned int line, 151 handle_t *handle, struct buffer_head *bh) 152 { 153 int err = 0; 154 155 might_sleep(); 156 157 if (ext4_handle_valid(handle)) { 158 err = jbd2_journal_get_write_access(handle, bh); 159 if (err) 160 ext4_journal_abort_handle(where, line, __func__, bh, 161 handle, err); 162 } 163 return err; 164 } 165 166 /* 167 * The ext4 forget function must perform a revoke if we are freeing data 168 * which has been journaled. Metadata (eg. indirect blocks) must be 169 * revoked in all cases. 170 * 171 * "bh" may be NULL: a metadata block may have been freed from memory 172 * but there may still be a record of it in the journal, and that record 173 * still needs to be revoked. 174 * 175 * If the handle isn't valid we're not journaling, but we still need to 176 * call into ext4_journal_revoke() to put the buffer head. 177 */ 178 int __ext4_forget(const char *where, unsigned int line, handle_t *handle, 179 int is_metadata, struct inode *inode, 180 struct buffer_head *bh, ext4_fsblk_t blocknr) 181 { 182 int err; 183 184 might_sleep(); 185 186 trace_ext4_forget(inode, is_metadata, blocknr); 187 BUFFER_TRACE(bh, "enter"); 188 189 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, " 190 "data mode %x\n", 191 bh, is_metadata, inode->i_mode, 192 test_opt(inode->i_sb, DATA_FLAGS)); 193 194 /* In the no journal case, we can just do a bforget and return */ 195 if (!ext4_handle_valid(handle)) { 196 bforget(bh); 197 return 0; 198 } 199 200 /* Never use the revoke function if we are doing full data 201 * journaling: there is no need to, and a V1 superblock won't 202 * support it. Otherwise, only skip the revoke on un-journaled 203 * data blocks. */ 204 205 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA || 206 (!is_metadata && !ext4_should_journal_data(inode))) { 207 if (bh) { 208 BUFFER_TRACE(bh, "call jbd2_journal_forget"); 209 err = jbd2_journal_forget(handle, bh); 210 if (err) 211 ext4_journal_abort_handle(where, line, __func__, 212 bh, handle, err); 213 return err; 214 } 215 return 0; 216 } 217 218 /* 219 * data!=journal && (is_metadata || should_journal_data(inode)) 220 */ 221 BUFFER_TRACE(bh, "call jbd2_journal_revoke"); 222 err = jbd2_journal_revoke(handle, blocknr, bh); 223 if (err) { 224 ext4_journal_abort_handle(where, line, __func__, 225 bh, handle, err); 226 __ext4_abort(inode->i_sb, where, line, 227 "error %d when attempting revoke", err); 228 } 229 BUFFER_TRACE(bh, "exit"); 230 return err; 231 } 232 233 int __ext4_journal_get_create_access(const char *where, unsigned int line, 234 handle_t *handle, struct buffer_head *bh) 235 { 236 int err = 0; 237 238 if (ext4_handle_valid(handle)) { 239 err = jbd2_journal_get_create_access(handle, bh); 240 if (err) 241 ext4_journal_abort_handle(where, line, __func__, 242 bh, handle, err); 243 } 244 return err; 245 } 246 247 int __ext4_handle_dirty_metadata(const char *where, unsigned int line, 248 handle_t *handle, struct inode *inode, 249 struct buffer_head *bh) 250 { 251 int err = 0; 252 253 might_sleep(); 254 255 set_buffer_meta(bh); 256 set_buffer_prio(bh); 257 if (ext4_handle_valid(handle)) { 258 err = jbd2_journal_dirty_metadata(handle, bh); 259 /* Errors can only happen if there is a bug */ 260 if (WARN_ON_ONCE(err)) { 261 ext4_journal_abort_handle(where, line, __func__, bh, 262 handle, err); 263 if (inode == NULL) { 264 pr_err("EXT4: jbd2_journal_dirty_metadata " 265 "failed: handle type %u started at " 266 "line %u, credits %u/%u, errcode %d", 267 handle->h_type, 268 handle->h_line_no, 269 handle->h_requested_credits, 270 handle->h_buffer_credits, err); 271 return err; 272 } 273 ext4_error_inode(inode, where, line, 274 bh->b_blocknr, 275 "journal_dirty_metadata failed: " 276 "handle type %u started at line %u, " 277 "credits %u/%u, errcode %d", 278 handle->h_type, 279 handle->h_line_no, 280 handle->h_requested_credits, 281 handle->h_buffer_credits, err); 282 } 283 } else { 284 if (inode) 285 mark_buffer_dirty_inode(bh, inode); 286 else 287 mark_buffer_dirty(bh); 288 if (inode && inode_needs_sync(inode)) { 289 sync_dirty_buffer(bh); 290 if (buffer_req(bh) && !buffer_uptodate(bh)) { 291 struct ext4_super_block *es; 292 293 es = EXT4_SB(inode->i_sb)->s_es; 294 es->s_last_error_block = 295 cpu_to_le64(bh->b_blocknr); 296 ext4_error_inode(inode, where, line, 297 bh->b_blocknr, 298 "IO error syncing itable block"); 299 err = -EIO; 300 } 301 } 302 } 303 return err; 304 } 305 306 int __ext4_handle_dirty_super(const char *where, unsigned int line, 307 handle_t *handle, struct super_block *sb) 308 { 309 struct buffer_head *bh = EXT4_SB(sb)->s_sbh; 310 int err = 0; 311 312 ext4_superblock_csum_set(sb); 313 if (ext4_handle_valid(handle)) { 314 err = jbd2_journal_dirty_metadata(handle, bh); 315 if (err) 316 ext4_journal_abort_handle(where, line, __func__, 317 bh, handle, err); 318 } else 319 mark_buffer_dirty(bh); 320 return err; 321 } 322