diff options
Diffstat (limited to 'fs/jbd2/journal.c')
| -rw-r--r-- | fs/jbd2/journal.c | 138 |
1 files changed, 117 insertions, 21 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index fc5f2acc9f18..c5ff177400ff 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -742,6 +742,85 @@ struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal) return jbd2_journal_add_journal_head(bh); } +/* + * Return tid of the oldest transaction in the journal and block in the journal + * where the transaction starts. + * + * If the journal is now empty, return which will be the next transaction ID + * we will write and where will that transaction start. + * + * The return value is 0 if journal tail cannot be pushed any further, 1 if + * it can. + */ +int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid, + unsigned long *block) +{ + transaction_t *transaction; + int ret; + + read_lock(&journal->j_state_lock); + spin_lock(&journal->j_list_lock); + transaction = journal->j_checkpoint_transactions; + if (transaction) { + *tid = transaction->t_tid; + *block = transaction->t_log_start; + } else if ((transaction = journal->j_committing_transaction) != NULL) { + *tid = transaction->t_tid; + *block = transaction->t_log_start; + } else if ((transaction = journal->j_running_transaction) != NULL) { + *tid = transaction->t_tid; + *block = journal->j_head; + } else { + *tid = journal->j_transaction_sequence; + *block = journal->j_head; + } + ret = tid_gt(*tid, journal->j_tail_sequence); + spin_unlock(&journal->j_list_lock); + read_unlock(&journal->j_state_lock); + + return ret; +} + +/* + * Update information in journal structure and in on disk journal superblock + * about log tail. This function does not check whether information passed in + * really pushes log tail further. It's responsibility of the caller to make + * sure provided log tail information is valid (e.g. by holding + * j_checkpoint_mutex all the time between computing log tail and calling this + * function as is the case with jbd2_cleanup_journal_tail()). + * + * Requires j_checkpoint_mutex + */ +void __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block) +{ + unsigned long freed; + + BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); + + /* + * We cannot afford for write to remain in drive's caches since as + * soon as we update j_tail, next transaction can start reusing journal + * space and if we lose sb update during power failure we'd replay + * old transaction with possibly newly overwritten data. + */ + jbd2_journal_update_sb_log_tail(journal, tid, block, WRITE_FUA); + write_lock(&journal->j_state_lock); + freed = block - journal->j_tail; + if (block < journal->j_tail) + freed += journal->j_last - journal->j_first; + + trace_jbd2_update_log_tail(journal, tid, block, freed); + jbd_debug(1, + "Cleaning journal tail from %d to %d (offset %lu), " + "freeing %lu\n", + journal->j_tail_sequence, tid, block, freed); + + journal->j_free += freed; + journal->j_tail_sequence = tid; + journal->j_tail = block; + write_unlock(&journal->j_state_lock); +} + struct jbd2_stats_proc_session { journal_t *journal; struct transaction_stats_s *stats; @@ -1125,18 +1204,30 @@ static int journal_reset(journal_t *journal) } else { /* Lock here to make assertions happy... */ mutex_lock(&journal->j_checkpoint_mutex); - /* Add the dynamic fields and write it to disk. */ - jbd2_journal_update_sb_log_tail(journal); + /* + * Update log tail information. We use WRITE_FUA since new + * transaction will start reusing journal space and so we + * must make sure information about current log tail is on + * disk before that. + */ + jbd2_journal_update_sb_log_tail(journal, + journal->j_tail_sequence, + journal->j_tail, + WRITE_FUA); mutex_unlock(&journal->j_checkpoint_mutex); } return jbd2_journal_start_thread(journal); } -static void jbd2_write_superblock(journal_t *journal) +static void jbd2_write_superblock(journal_t *journal, int write_op) { struct buffer_head *bh = journal->j_sb_buffer; + int ret; - trace_jbd2_write_superblock(journal); + trace_jbd2_write_superblock(journal, write_op); + if (!(journal->j_flags & JBD2_BARRIER)) + write_op &= ~(REQ_FUA | REQ_FLUSH); + lock_buffer(bh); if (buffer_write_io_error(bh)) { /* * Oh, dear. A previous attempt to write the journal @@ -1152,40 +1243,45 @@ static void jbd2_write_superblock(journal_t *journal) clear_buffer_write_io_error(bh); set_buffer_uptodate(bh); } - - BUFFER_TRACE(bh, "marking dirty"); - mark_buffer_dirty(bh); - sync_dirty_buffer(bh); + get_bh(bh); + bh->b_end_io = end_buffer_write_sync; + ret = submit_bh(write_op, bh); + wait_on_buffer(bh); if (buffer_write_io_error(bh)) { - printk(KERN_ERR "JBD2: I/O error detected " - "when updating journal superblock for %s.\n", - journal->j_devname); clear_buffer_write_io_error(bh); set_buffer_uptodate(bh); + ret = -EIO; + } + if (ret) { + printk(KERN_ERR "JBD2: Error %d detected when updating " + "journal superblock for %s.\n", ret, + journal->j_devname); } } /** * jbd2_journal_update_sb_log_tail() - Update log tail in journal sb on disk. * @journal: The journal to update. + * @tail_tid: TID of the new transaction at the tail of the log + * @tail_block: The first block of the transaction at the tail of the log + * @write_op: With which operation should we write the journal sb * * Update a journal's superblock information about log tail and write it to * disk, waiting for the IO to complete. */ -void jbd2_journal_update_sb_log_tail(journal_t *journal) +void jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid, + unsigned long tail_block, int write_op) { journal_superblock_t *sb = journal->j_superblock; BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); - read_lock(&journal->j_state_lock); - jbd_debug(1, "JBD2: updating superblock (start %ld, seq %d)\n", - journal->j_tail, journal->j_tail_sequence); + jbd_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n", + tail_block, tail_tid); - sb->s_sequence = cpu_to_be32(journal->j_tail_sequence); - sb->s_start = cpu_to_be32(journal->j_tail); - read_unlock(&journal->j_state_lock); + sb->s_sequence = cpu_to_be32(tail_tid); + sb->s_start = cpu_to_be32(tail_block); - jbd2_write_superblock(journal); + jbd2_write_superblock(journal, write_op); /* Log is no longer empty */ write_lock(&journal->j_state_lock); @@ -1214,7 +1310,7 @@ static void jbd2_mark_journal_empty(journal_t *journal) sb->s_start = cpu_to_be32(0); read_unlock(&journal->j_state_lock); - jbd2_write_superblock(journal); + jbd2_write_superblock(journal, WRITE_FUA); /* Log is no longer empty */ write_lock(&journal->j_state_lock); @@ -1240,7 +1336,7 @@ static void jbd2_journal_update_sb_errno(journal_t *journal) sb->s_errno = cpu_to_be32(journal->j_errno); read_unlock(&journal->j_state_lock); - jbd2_write_superblock(journal); + jbd2_write_superblock(journal, WRITE_SYNC); } /* |