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;
journal->j_errno);
journal->j_flags |= JBD2_FLUSHED;
} else {
- /* 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);
}
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;
+ 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
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;
- 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);
WARN_ON(!sb->s_sequence);
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);
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);
}
/*
git.openpandora.org / pandora-kernel.git / blobdiff