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