1 files changed, 84 insertions, 111 deletions

diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 7f34f4716165..f1507e5b7c9a 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -255,81 +255,6 @@ __flush_batch(journal_t *journal, int *batch_count)
 }
 
 /*
- * Try to flush one buffer from the checkpoint list to disk.
- *
- * Return 1 if something happened which requires us to abort the current
- * scan of the checkpoint list.  Return <0 if the buffer has failed to
- * be written out.
- *
- * Called with j_list_lock held and drops it if 1 is returned
- */
-static int __process_buffer(journal_t *journal, struct journal_head *jh,
-                            int *batch_count, transaction_t *transaction)
-{
-        struct buffer_head *bh = jh2bh(jh);
-        int ret = 0;
-
-        if (buffer_locked(bh)) {
-                get_bh(bh);
-                spin_unlock(&journal->j_list_lock);
-                wait_on_buffer(bh);
-                /* the journal_head may have gone by now */
-                BUFFER_TRACE(bh, "brelse");
-                __brelse(bh);
-                ret = 1;
-        } else if (jh->b_transaction != NULL) {
-                transaction_t *t = jh->b_transaction;
-                tid_t tid = t->t_tid;
-
-                transaction->t_chp_stats.cs_forced_to_close++;
-                spin_unlock(&journal->j_list_lock);
-                if (unlikely(journal->j_flags & JBD2_UNMOUNT))
-                        /*
-                         * The journal thread is dead; so starting and
-                         * waiting for a commit to finish will cause
-                         * us to wait for a _very_ long time.
-                         */
-                        printk(KERN_ERR "JBD2: %s: "
-                               "Waiting for Godot: block %llu\n",
-                               journal->j_devname,
-                               (unsigned long long) bh->b_blocknr);
-                jbd2_log_start_commit(journal, tid);
-                jbd2_log_wait_commit(journal, tid);
-                ret = 1;
-        } else if (!buffer_dirty(bh)) {
-                ret = 1;
-                if (unlikely(buffer_write_io_error(bh)))
-                        ret = -EIO;
-                get_bh(bh);
-                BUFFER_TRACE(bh, "remove from checkpoint");
-                __jbd2_journal_remove_checkpoint(jh);
-                spin_unlock(&journal->j_list_lock);
-                __brelse(bh);
-        } else {
-                /*
-                 * Important: we are about to write the buffer, and
-                 * possibly block, while still holding the journal lock.
-                 * We cannot afford to let the transaction logic start
-                 * messing around with this buffer before we write it to
-                 * disk, as that would break recoverability.
-                 */
-                BUFFER_TRACE(bh, "queue");
-                get_bh(bh);
-                J_ASSERT_BH(bh, !buffer_jwrite(bh));
-                journal->j_chkpt_bhs[*batch_count] = bh;
-                __buffer_relink_io(jh);
-                transaction->t_chp_stats.cs_written++;
-                (*batch_count)++;
-                if (*batch_count == JBD2_NR_BATCH) {
-                        spin_unlock(&journal->j_list_lock);
-                        __flush_batch(journal, batch_count);
-                        ret = 1;
-                }
-        }
-        return ret;
-}
-
-/*
  * Perform an actual checkpoint. We take the first transaction on the
  * list of transactions to be checkpointed and send all its buffers
  * to disk. We submit larger chunks of data at once.
@@ -339,9 +264,11 @@ static int __process_buffer(journal_t *journal, struct journal_head *jh,
  */
 int jbd2_log_do_checkpoint(journal_t *journal)
 {
-        transaction_t *transaction;
-        tid_t this_tid;
-        int result;
+        struct journal_head     *jh;
+        struct buffer_head      *bh;
+        transaction_t           *transaction;
+        tid_t                   this_tid;
+        int                     err, result, batch_count = 0;
 
         jbd_debug(1, "Start checkpoint\n");
 
@@ -374,46 +301,92 @@ restart:
          * done (maybe it's a new transaction, but it fell at the same
          * address).
          */
-        if (journal->j_checkpoint_transactions == transaction &&
-                        transaction->t_tid == this_tid) {
-                int batch_count = 0;
-                struct journal_head *jh;
-                int retry = 0, err;
-
-                while (!retry && transaction->t_checkpoint_list) {
-                        jh = transaction->t_checkpoint_list;
-                        retry = __process_buffer(journal, jh, &batch_count,
-                                                 transaction);
-                        if (retry < 0 && !result)
-                                result = retry;
-                        if (!retry && (need_resched() ||
-                                spin_needbreak(&journal->j_list_lock))) {
-                                spin_unlock(&journal->j_list_lock);
-                                retry = 1;
-                                break;
-                        }
-                }
+        if (journal->j_checkpoint_transactions != transaction ||
+            transaction->t_tid != this_tid)
+                goto out;
 
-                if (batch_count) {
-                        if (!retry) {
-                                spin_unlock(&journal->j_list_lock);
-                                retry = 1;
-                        }
-                        __flush_batch(journal, &batch_count);
+        /* checkpoint all of the transaction's buffers */
+        while (transaction->t_checkpoint_list) {
+                jh = transaction->t_checkpoint_list;
+                bh = jh2bh(jh);
+
+                if (buffer_locked(bh)) {
+                        spin_unlock(&journal->j_list_lock);
+                        get_bh(bh);
+                        wait_on_buffer(bh);
+                        /* the journal_head may have gone by now */
+                        BUFFER_TRACE(bh, "brelse");
+                        __brelse(bh);
+                        goto retry;
                 }
+                if (jh->b_transaction != NULL) {
+                        transaction_t *t = jh->b_transaction;
+                        tid_t tid = t->t_tid;
 
-                if (retry) {
-                        spin_lock(&journal->j_list_lock);
-                        goto restart;
+                        transaction->t_chp_stats.cs_forced_to_close++;
+                        spin_unlock(&journal->j_list_lock);
+                        if (unlikely(journal->j_flags & JBD2_UNMOUNT))
+                                /*
+                                 * The journal thread is dead; so
+                                 * starting and waiting for a commit
+                                 * to finish will cause us to wait for
+                                 * a _very_ long time.
+                                 */
+                                printk(KERN_ERR
+                "JBD2: %s: Waiting for Godot: block %llu\n",
+                journal->j_devname, (unsigned long long) bh->b_blocknr);
+
+                        jbd2_log_start_commit(journal, tid);
+                        jbd2_log_wait_commit(journal, tid);
+                        goto retry;
+                }
+                if (!buffer_dirty(bh)) {
+                        if (unlikely(buffer_write_io_error(bh)) && !result)
+                                result = -EIO;
+                        get_bh(bh);
+                        BUFFER_TRACE(bh, "remove from checkpoint");
+                        __jbd2_journal_remove_checkpoint(jh);
+                        spin_unlock(&journal->j_list_lock);
+                        __brelse(bh);
+                        goto retry;
                 }
                 /*
-                 * Now we have cleaned up the first transaction's checkpoint
-                 * list. Let's clean up the second one
+                 * Important: we are about to write the buffer, and
+                 * possibly block, while still holding the journal
+                 * lock.  We cannot afford to let the transaction
+                 * logic start messing around with this buffer before
+                 * we write it to disk, as that would break
+                 * recoverability.
                  */
-                err = __wait_cp_io(journal, transaction);
-                if (!result)
-                        result = err;
+                BUFFER_TRACE(bh, "queue");
+                get_bh(bh);
+                J_ASSERT_BH(bh, !buffer_jwrite(bh));
+                journal->j_chkpt_bhs[batch_count++] = bh;
+                __buffer_relink_io(jh);
+                transaction->t_chp_stats.cs_written++;
+                if ((batch_count == JBD2_NR_BATCH) ||
+                    need_resched() ||
+                    spin_needbreak(&journal->j_list_lock))
+                        goto unlock_and_flush;
         }
+
+        if (batch_count) {
+                unlock_and_flush:
+                        spin_unlock(&journal->j_list_lock);
+                retry:
+                        if (batch_count)
+                                __flush_batch(journal, &batch_count);
+                        spin_lock(&journal->j_list_lock);
+                        goto restart;
+        }
+
+        /*
+         * Now we issued all of the transaction's buffers, let's deal
+         * with the buffers that are out for I/O.
+         */
+        err = __wait_cp_io(journal, transaction);
+        if (!result)
+                result = err;
 out:
         spin_unlock(&journal->j_list_lock);
         if (result < 0)