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 void ext4_journal_abort_handle(const char *caller, unsigned int line, 126 const char *err_fn, struct buffer_head *bh, 127 handle_t *handle, int err) 128 { 129 char nbuf[16]; 130 const char *errstr = ext4_decode_error(NULL, err, nbuf); 131 132 BUG_ON(!ext4_handle_valid(handle)); 133 134 if (bh) 135 BUFFER_TRACE(bh, "abort"); 136 137 if (!handle->h_err) 138 handle->h_err = err; 139 140 if (is_handle_aborted(handle)) 141 return; 142 143 printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n", 144 caller, line, errstr, err_fn); 145 146 jbd2_journal_abort_handle(handle); 147 } 148 149 int __ext4_journal_get_write_access(const char *where, unsigned int line, 150 handle_t *handle, struct buffer_head *bh) 151 { 152 int err = 0; 153 154 might_sleep(); 155 156 if (ext4_handle_valid(handle)) { 157 err = jbd2_journal_get_write_access(handle, bh); 158 if (err) 159 ext4_journal_abort_handle(where, line, __func__, bh, 160 handle, err); 161 } 162 return err; 163 } 164 165 /* 166 * The ext4 forget function must perform a revoke if we are freeing data 167 * which has been journaled. Metadata (eg. indirect blocks) must be 168 * revoked in all cases. 169 * 170 * "bh" may be NULL: a metadata block may have been freed from memory 171 * but there may still be a record of it in the journal, and that record 172 * still needs to be revoked. 173 * 174 * If the handle isn't valid we're not journaling, but we still need to 175 * call into ext4_journal_revoke() to put the buffer head. 176 */ 177 int __ext4_forget(const char *where, unsigned int line, handle_t *handle, 178 int is_metadata, struct inode *inode, 179 struct buffer_head *bh, ext4_fsblk_t blocknr) 180 { 181 int err; 182 183 might_sleep(); 184 185 trace_ext4_forget(inode, is_metadata, blocknr); 186 BUFFER_TRACE(bh, "enter"); 187 188 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, " 189 "data mode %x\n", 190 bh, is_metadata, inode->i_mode, 191 test_opt(inode->i_sb, DATA_FLAGS)); 192 193 /* In the no journal case, we can just do a bforget and return */ 194 if (!ext4_handle_valid(handle)) { 195 bforget(bh); 196 return 0; 197 } 198 199 /* Never use the revoke function if we are doing full data 200 * journaling: there is no need to, and a V1 superblock won't 201 * support it. Otherwise, only skip the revoke on un-journaled 202 * data blocks. */ 203 204 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA || 205 (!is_metadata && !ext4_should_journal_data(inode))) { 206 if (bh) { 207 BUFFER_TRACE(bh, "call jbd2_journal_forget"); 208 err = jbd2_journal_forget(handle, bh); 209 if (err) 210 ext4_journal_abort_handle(where, line, __func__, 211 bh, handle, err); 212 return err; 213 } 214 return 0; 215 } 216 217 /* 218 * data!=journal && (is_metadata || should_journal_data(inode)) 219 */ 220 BUFFER_TRACE(bh, "call jbd2_journal_revoke"); 221 err = jbd2_journal_revoke(handle, blocknr, bh); 222 if (err) { 223 ext4_journal_abort_handle(where, line, __func__, 224 bh, handle, err); 225 __ext4_abort(inode->i_sb, where, line, 226 "error %d when attempting revoke", err); 227 } 228 BUFFER_TRACE(bh, "exit"); 229 return err; 230 } 231 232 int __ext4_journal_get_create_access(const char *where, unsigned int line, 233 handle_t *handle, struct buffer_head *bh) 234 { 235 int err = 0; 236 237 if (ext4_handle_valid(handle)) { 238 err = jbd2_journal_get_create_access(handle, bh); 239 if (err) 240 ext4_journal_abort_handle(where, line, __func__, 241 bh, handle, err); 242 } 243 return err; 244 } 245 246 int __ext4_handle_dirty_metadata(const char *where, unsigned int line, 247 handle_t *handle, struct inode *inode, 248 struct buffer_head *bh) 249 { 250 int err = 0; 251 252 might_sleep(); 253 254 set_buffer_meta(bh); 255 set_buffer_prio(bh); 256 if (ext4_handle_valid(handle)) { 257 err = jbd2_journal_dirty_metadata(handle, bh); 258 /* Errors can only happen if there is a bug */ 259 if (WARN_ON_ONCE(err)) { 260 ext4_journal_abort_handle(where, line, __func__, bh, 261 handle, err); 262 } 263 } else { 264 if (inode) 265 mark_buffer_dirty_inode(bh, inode); 266 else 267 mark_buffer_dirty(bh); 268 if (inode && inode_needs_sync(inode)) { 269 sync_dirty_buffer(bh); 270 if (buffer_req(bh) && !buffer_uptodate(bh)) { 271 struct ext4_super_block *es; 272 273 es = EXT4_SB(inode->i_sb)->s_es; 274 es->s_last_error_block = 275 cpu_to_le64(bh->b_blocknr); 276 ext4_error_inode(inode, where, line, 277 bh->b_blocknr, 278 "IO error syncing itable block"); 279 err = -EIO; 280 } 281 } 282 } 283 return err; 284 } 285 286 int __ext4_handle_dirty_super(const char *where, unsigned int line, 287 handle_t *handle, struct super_block *sb) 288 { 289 struct buffer_head *bh = EXT4_SB(sb)->s_sbh; 290 int err = 0; 291 292 ext4_superblock_csum_set(sb); 293 if (ext4_handle_valid(handle)) { 294 err = jbd2_journal_dirty_metadata(handle, bh); 295 if (err) 296 ext4_journal_abort_handle(where, line, __func__, 297 bh, handle, err); 298 } else 299 mark_buffer_dirty(bh); 300 return err; 301 } 302