LXR linux/fs/ext4/ext4

   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 */
  10static 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 */
  26static 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 */
  41static int ext4_journal_check_start(struct super_block *sb)
  42{
  43        journal_t *journal;
  44
  45        might_sleep();
  46
  47        if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
  48                return -EIO;
  49
  50        if (sb->s_flags & MS_RDONLY)
  51                return -EROFS;
  52        WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
  53        journal = EXT4_SB(sb)->s_journal;
  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 (journal && is_journal_aborted(journal)) {
  60                ext4_abort(sb, "Detected aborted journal");
  61                return -EROFS;
  62        }
  63        return 0;
  64}
  65
  66handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
  67                                  int type, int blocks, int rsv_blocks)
  68{
  69        journal_t *journal;
  70        int err;
  71
  72        trace_ext4_journal_start(sb, blocks, rsv_blocks, _RET_IP_);
  73        err = ext4_journal_check_start(sb);
  74        if (err < 0)
  75                return ERR_PTR(err);
  76
  77        journal = EXT4_SB(sb)->s_journal;
  78        if (!journal)
  79                return ext4_get_nojournal();
  80        return jbd2__journal_start(journal, blocks, rsv_blocks, GFP_NOFS,
  81                                   type, line);
  82}
  83
  84int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
  85{
  86        struct super_block *sb;
  87        int err;
  88        int rc;
  89
  90        if (!ext4_handle_valid(handle)) {
  91                ext4_put_nojournal(handle);
  92                return 0;
  93        }
  94
  95        err = handle->h_err;
  96        if (!handle->h_transaction) {
  97                rc = jbd2_journal_stop(handle);
  98                return err ? err : rc;
  99        }
 100
 101        sb = handle->h_transaction->t_journal->j_private;
 102        rc = jbd2_journal_stop(handle);
 103
 104        if (!err)
 105                err = rc;
 106        if (err)
 107                __ext4_std_error(sb, where, line, err);
 108        return err;
 109}
 110
 111handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
 112                                        int type)
 113{
 114        struct super_block *sb;
 115        int err;
 116
 117        if (!ext4_handle_valid(handle))
 118                return ext4_get_nojournal();
 119
 120        sb = handle->h_journal->j_private;
 121        trace_ext4_journal_start_reserved(sb, handle->h_buffer_credits,
 122                                          _RET_IP_);
 123        err = ext4_journal_check_start(sb);
 124        if (err < 0) {
 125                jbd2_journal_free_reserved(handle);
 126                return ERR_PTR(err);
 127        }
 128
 129        err = jbd2_journal_start_reserved(handle, type, line);
 130        if (err < 0)
 131                return ERR_PTR(err);
 132        return handle;
 133}
 134
 135static void ext4_journal_abort_handle(const char *caller, unsigned int line,
 136                                      const char *err_fn,
 137                                      struct buffer_head *bh,
 138                                      handle_t *handle, int err)
 139{
 140        char nbuf[16];
 141        const char *errstr = ext4_decode_error(NULL, err, nbuf);
 142
 143        BUG_ON(!ext4_handle_valid(handle));
 144
 145        if (bh)
 146                BUFFER_TRACE(bh, "abort");
 147
 148        if (!handle->h_err)
 149                handle->h_err = err;
 150
 151        if (is_handle_aborted(handle))
 152                return;
 153
 154        printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
 155               caller, line, errstr, err_fn);
 156
 157        jbd2_journal_abort_handle(handle);
 158}
 159
 160int __ext4_journal_get_write_access(const char *where, unsigned int line,
 161                                    handle_t *handle, struct buffer_head *bh)
 162{
 163        int err = 0;
 164
 165        might_sleep();
 166
 167        if (ext4_handle_valid(handle)) {
 168                struct super_block *sb;
 169
 170                sb = handle->h_transaction->t_journal->j_private;
 171                if (unlikely(ext4_forced_shutdown(EXT4_SB(sb)))) {
 172                        jbd2_journal_abort_handle(handle);
 173                        return -EIO;
 174                }
 175                err = jbd2_journal_get_write_access(handle, bh);
 176                if (err)
 177                        ext4_journal_abort_handle(where, line, __func__, bh,
 178                                                  handle, err);
 179        }
 180        return err;
 181}
 182
 183/*
 184 * The ext4 forget function must perform a revoke if we are freeing data
 185 * which has been journaled.  Metadata (eg. indirect blocks) must be
 186 * revoked in all cases.
 187 *
 188 * "bh" may be NULL: a metadata block may have been freed from memory
 189 * but there may still be a record of it in the journal, and that record
 190 * still needs to be revoked.
 191 *
 192 * If the handle isn't valid we're not journaling, but we still need to
 193 * call into ext4_journal_revoke() to put the buffer head.
 194 */
 195int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 196                  int is_metadata, struct inode *inode,
 197                  struct buffer_head *bh, ext4_fsblk_t blocknr)
 198{
 199        int err;
 200
 201        might_sleep();
 202
 203        trace_ext4_forget(inode, is_metadata, blocknr);
 204        BUFFER_TRACE(bh, "enter");
 205
 206        jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
 207                  "data mode %x\n",
 208                  bh, is_metadata, inode->i_mode,
 209                  test_opt(inode->i_sb, DATA_FLAGS));
 210
 211        /* In the no journal case, we can just do a bforget and return */
 212        if (!ext4_handle_valid(handle)) {
 213                bforget(bh);
 214                return 0;
 215        }
 216
 217        /* Never use the revoke function if we are doing full data
 218         * journaling: there is no need to, and a V1 superblock won't
 219         * support it.  Otherwise, only skip the revoke on un-journaled
 220         * data blocks. */
 221
 222        if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
 223            (!is_metadata && !ext4_should_journal_data(inode))) {
 224                if (bh) {
 225                        BUFFER_TRACE(bh, "call jbd2_journal_forget");
 226                        err = jbd2_journal_forget(handle, bh);
 227                        if (err)
 228                                ext4_journal_abort_handle(where, line, __func__,
 229                                                          bh, handle, err);
 230                        return err;
 231                }
 232                return 0;
 233        }
 234
 235        /*
 236         * data!=journal && (is_metadata || should_journal_data(inode))
 237         */
 238        BUFFER_TRACE(bh, "call jbd2_journal_revoke");
 239        err = jbd2_journal_revoke(handle, blocknr, bh);
 240        if (err) {
 241                ext4_journal_abort_handle(where, line, __func__,
 242                                          bh, handle, err);
 243                __ext4_abort(inode->i_sb, where, line,
 244                           "error %d when attempting revoke", err);
 245        }
 246        BUFFER_TRACE(bh, "exit");
 247        return err;
 248}
 249
 250int __ext4_journal_get_create_access(const char *where, unsigned int line,
 251                                handle_t *handle, struct buffer_head *bh)
 252{
 253        int err = 0;
 254
 255        if (ext4_handle_valid(handle)) {
 256                err = jbd2_journal_get_create_access(handle, bh);
 257                if (err)
 258                        ext4_journal_abort_handle(where, line, __func__,
 259                                                  bh, handle, err);
 260        }
 261        return err;
 262}
 263
 264int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 265                                 handle_t *handle, struct inode *inode,
 266                                 struct buffer_head *bh)
 267{
 268        int err = 0;
 269
 270        might_sleep();
 271
 272        set_buffer_meta(bh);
 273        set_buffer_prio(bh);
 274        if (ext4_handle_valid(handle)) {
 275                err = jbd2_journal_dirty_metadata(handle, bh);
 276                /* Errors can only happen due to aborted journal or a nasty bug */
 277                if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) {
 278                        ext4_journal_abort_handle(where, line, __func__, bh,
 279                                                  handle, err);
 280                        if (inode == NULL) {
 281                                pr_err("EXT4: jbd2_journal_dirty_metadata "
 282                                       "failed: handle type %u started at "
 283                                       "line %u, credits %u/%u, errcode %d",
 284                                       handle->h_type,
 285                                       handle->h_line_no,
 286                                       handle->h_requested_credits,
 287                                       handle->h_buffer_credits, err);
 288                                return err;
 289                        }
 290                        ext4_error_inode(inode, where, line,
 291                                         bh->b_blocknr,
 292                                         "journal_dirty_metadata failed: "
 293                                         "handle type %u started at line %u, "
 294                                         "credits %u/%u, errcode %d",
 295                                         handle->h_type,
 296                                         handle->h_line_no,
 297                                         handle->h_requested_credits,
 298                                         handle->h_buffer_credits, err);
 299                }
 300        } else {
 301                if (inode)
 302                        mark_buffer_dirty_inode(bh, inode);
 303                else
 304                        mark_buffer_dirty(bh);
 305                if (inode && inode_needs_sync(inode)) {
 306                        sync_dirty_buffer(bh);
 307                        if (buffer_req(bh) && !buffer_uptodate(bh)) {
 308                                struct ext4_super_block *es;
 309
 310                                es = EXT4_SB(inode->i_sb)->s_es;
 311                                es->s_last_error_block =
 312                                        cpu_to_le64(bh->b_blocknr);
 313                                ext4_error_inode(inode, where, line,
 314                                                 bh->b_blocknr,
 315                                        "IO error syncing itable block");
 316                                err = -EIO;
 317                        }
 318                }
 319        }
 320        return err;
 321}
 322
 323int __ext4_handle_dirty_super(const char *where, unsigned int line,
 324                              handle_t *handle, struct super_block *sb)
 325{
 326        struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
 327        int err = 0;
 328
 329        ext4_superblock_csum_set(sb);
 330        if (ext4_handle_valid(handle)) {
 331                err = jbd2_journal_dirty_metadata(handle, bh);
 332                if (err)
 333                        ext4_journal_abort_handle(where, line, __func__,
 334                                                  bh, handle, err);
 335        } else
 336                mark_buffer_dirty(bh);
 337        return err;
 338}
 339