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 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line, 42 int type, int nblocks) 43 { 44 journal_t *journal; 45 46 might_sleep(); 47 48 trace_ext4_journal_start(sb, nblocks, _RET_IP_); 49 if (sb->s_flags & MS_RDONLY) 50 return ERR_PTR(-EROFS); 51 52 WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE); 53 journal = EXT4_SB(sb)->s_journal; 54 if (!journal) 55 return ext4_get_nojournal(); 56 /* 57 * Special case here: if the journal has aborted behind our 58 * backs (eg. EIO in the commit thread), then we still need to 59 * take the FS itself readonly cleanly. 60 */ 61 if (is_journal_aborted(journal)) { 62 ext4_abort(sb, "Detected aborted journal"); 63 return ERR_PTR(-EROFS); 64 } 65 return jbd2__journal_start(journal, nblocks, GFP_NOFS, type, line); 66 } 67 68 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle) 69 { 70 struct super_block *sb; 71 int err; 72 int rc; 73 74 if (!ext4_handle_valid(handle)) { 75 ext4_put_nojournal(handle); 76 return 0; 77 } 78 sb = handle->h_transaction->t_journal->j_private; 79 err = handle->h_err; 80 rc = jbd2_journal_stop(handle); 81 82 if (!err) 83 err = rc; 84 if (err) 85 __ext4_std_error(sb, where, line, err); 86 return err; 87 } 88 89 void ext4_journal_abort_handle(const char *caller, unsigned int line, 90 const char *err_fn, struct buffer_head *bh, 91 handle_t *handle, int err) 92 { 93 char nbuf[16]; 94 const char *errstr = ext4_decode_error(NULL, err, nbuf); 95 96 BUG_ON(!ext4_handle_valid(handle)); 97 98 if (bh) 99 BUFFER_TRACE(bh, "abort"); 100 101 if (!handle->h_err) 102 handle->h_err = err; 103 104 if (is_handle_aborted(handle)) 105 return; 106 107 printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n", 108 caller, line, errstr, err_fn); 109 110 jbd2_journal_abort_handle(handle); 111 } 112 113 int __ext4_journal_get_write_access(const char *where, unsigned int line, 114 handle_t *handle, struct buffer_head *bh) 115 { 116 int err = 0; 117 118 might_sleep(); 119 120 if (ext4_handle_valid(handle)) { 121 err = jbd2_journal_get_write_access(handle, bh); 122 if (err) 123 ext4_journal_abort_handle(where, line, __func__, bh, 124 handle, err); 125 } 126 return err; 127 } 128 129 /* 130 * The ext4 forget function must perform a revoke if we are freeing data 131 * which has been journaled. Metadata (eg. indirect blocks) must be 132 * revoked in all cases. 133 * 134 * "bh" may be NULL: a metadata block may have been freed from memory 135 * but there may still be a record of it in the journal, and that record 136 * still needs to be revoked. 137 * 138 * If the handle isn't valid we're not journaling, but we still need to 139 * call into ext4_journal_revoke() to put the buffer head. 140 */ 141 int __ext4_forget(const char *where, unsigned int line, handle_t *handle, 142 int is_metadata, struct inode *inode, 143 struct buffer_head *bh, ext4_fsblk_t blocknr) 144 { 145 int err; 146 147 might_sleep(); 148 149 trace_ext4_forget(inode, is_metadata, blocknr); 150 BUFFER_TRACE(bh, "enter"); 151 152 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, " 153 "data mode %x\n", 154 bh, is_metadata, inode->i_mode, 155 test_opt(inode->i_sb, DATA_FLAGS)); 156 157 /* In the no journal case, we can just do a bforget and return */ 158 if (!ext4_handle_valid(handle)) { 159 bforget(bh); 160 return 0; 161 } 162 163 /* Never use the revoke function if we are doing full data 164 * journaling: there is no need to, and a V1 superblock won't 165 * support it. Otherwise, only skip the revoke on un-journaled 166 * data blocks. */ 167 168 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA || 169 (!is_metadata && !ext4_should_journal_data(inode))) { 170 if (bh) { 171 BUFFER_TRACE(bh, "call jbd2_journal_forget"); 172 err = jbd2_journal_forget(handle, bh); 173 if (err) 174 ext4_journal_abort_handle(where, line, __func__, 175 bh, handle, err); 176 return err; 177 } 178 return 0; 179 } 180 181 /* 182 * data!=journal && (is_metadata || should_journal_data(inode)) 183 */ 184 BUFFER_TRACE(bh, "call jbd2_journal_revoke"); 185 err = jbd2_journal_revoke(handle, blocknr, bh); 186 if (err) { 187 ext4_journal_abort_handle(where, line, __func__, 188 bh, handle, err); 189 __ext4_abort(inode->i_sb, where, line, 190 "error %d when attempting revoke", err); 191 } 192 BUFFER_TRACE(bh, "exit"); 193 return err; 194 } 195 196 int __ext4_journal_get_create_access(const char *where, unsigned int line, 197 handle_t *handle, struct buffer_head *bh) 198 { 199 int err = 0; 200 201 if (ext4_handle_valid(handle)) { 202 err = jbd2_journal_get_create_access(handle, bh); 203 if (err) 204 ext4_journal_abort_handle(where, line, __func__, 205 bh, handle, err); 206 } 207 return err; 208 } 209 210 int __ext4_handle_dirty_metadata(const char *where, unsigned int line, 211 handle_t *handle, struct inode *inode, 212 struct buffer_head *bh) 213 { 214 int err = 0; 215 216 might_sleep(); 217 218 set_buffer_meta(bh); 219 set_buffer_prio(bh); 220 if (ext4_handle_valid(handle)) { 221 err = jbd2_journal_dirty_metadata(handle, bh); 222 if (err) { 223 /* Errors can only happen if there is a bug */ 224 handle->h_err = err; 225 __ext4_journal_stop(where, line, handle); 226 } 227 } else { 228 if (inode) 229 mark_buffer_dirty_inode(bh, inode); 230 else 231 mark_buffer_dirty(bh); 232 if (inode && inode_needs_sync(inode)) { 233 sync_dirty_buffer(bh); 234 if (buffer_req(bh) && !buffer_uptodate(bh)) { 235 struct ext4_super_block *es; 236 237 es = EXT4_SB(inode->i_sb)->s_es; 238 es->s_last_error_block = 239 cpu_to_le64(bh->b_blocknr); 240 ext4_error_inode(inode, where, line, 241 bh->b_blocknr, 242 "IO error syncing itable block"); 243 err = -EIO; 244 } 245 } 246 } 247 return err; 248 } 249 250 int __ext4_handle_dirty_super(const char *where, unsigned int line, 251 handle_t *handle, struct super_block *sb) 252 { 253 struct buffer_head *bh = EXT4_SB(sb)->s_sbh; 254 int err = 0; 255 256 ext4_superblock_csum_set(sb); 257 if (ext4_handle_valid(handle)) { 258 err = jbd2_journal_dirty_metadata(handle, bh); 259 if (err) 260 ext4_journal_abort_handle(where, line, __func__, 261 bh, handle, err); 262 } else 263 mark_buffer_dirty(bh); 264 return err; 265 } 266