jbd2: Remove data=ordered mode support using jbd buffer heads

Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 8 insertions, 213 deletions

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 3ca107b5c86b..483183d15ed5 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -37,8 +37,8 @@ static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
 }
 
 /*
- * When an ext3-ordered file is truncated, it is possible that many pages are
- * not sucessfully freed, because they are attached to a committing transaction.
+ * When an ext4 file is truncated, it is possible that some pages are not
+ * successfully freed, because they are attached to a committing transaction.
  * After the transaction commits, these pages are left on the LRU, with no
  * ->mapping, and with attached buffers.  These pages are trivially reclaimable
  * by the VM, but their apparent absence upsets the VM accounting, and it makes
@@ -80,21 +80,6 @@ nope:
 }
 
 /*
- * Try to acquire jbd_lock_bh_state() against the buffer, when j_list_lock is
- * held.  For ranking reasons we must trylock.  If we lose, schedule away and
- * return 0.  j_list_lock is dropped in this case.
- */
-static int inverted_lock(journal_t *journal, struct buffer_head *bh)
-{
-        if (!jbd_trylock_bh_state(bh)) {
-                spin_unlock(&journal->j_list_lock);
-                schedule();
-                return 0;
-        }
-        return 1;
-}
-
-/*
  * Done it all: now submit the commit record.  We should have
  * cleaned up our previous buffers by now, so if we are in abort
  * mode we can now just skip the rest of the journal write
@@ -200,162 +185,6 @@ static int journal_wait_on_commit_record(struct buffer_head *bh)
 }
 
 /*
- * Wait for all submitted IO to complete.
- */
-static int journal_wait_on_locked_list(journal_t *journal,
-                                       transaction_t *commit_transaction)
-{
-        int ret = 0;
-        struct journal_head *jh;
-
-        while (commit_transaction->t_locked_list) {
-                struct buffer_head *bh;
-
-                jh = commit_transaction->t_locked_list->b_tprev;
-                bh = jh2bh(jh);
-                get_bh(bh);
-                if (buffer_locked(bh)) {
-                        spin_unlock(&journal->j_list_lock);
-                        wait_on_buffer(bh);
-                        if (unlikely(!buffer_uptodate(bh)))
-                                ret = -EIO;
-                        spin_lock(&journal->j_list_lock);
-                }
-                if (!inverted_lock(journal, bh)) {
-                        put_bh(bh);
-                        spin_lock(&journal->j_list_lock);
-                        continue;
-                }
-                if (buffer_jbd(bh) && jh->b_jlist == BJ_Locked) {
-                        __jbd2_journal_unfile_buffer(jh);
-                        jbd_unlock_bh_state(bh);
-                        jbd2_journal_remove_journal_head(bh);
-                        put_bh(bh);
-                } else {
-                        jbd_unlock_bh_state(bh);
-                }
-                put_bh(bh);
-                cond_resched_lock(&journal->j_list_lock);
-        }
-        return ret;
-  }
-
-static void journal_do_submit_data(struct buffer_head **wbuf, int bufs)
-{
-        int i;
-
-        for (i = 0; i < bufs; i++) {
-                wbuf[i]->b_end_io = end_buffer_write_sync;
-                /* We use-up our safety reference in submit_bh() */
-                submit_bh(WRITE, wbuf[i]);
-        }
-}
-
-/*
- *  Submit all the data buffers to disk
- */
-static void journal_submit_data_buffers(journal_t *journal,
-                                transaction_t *commit_transaction)
-{
-        struct journal_head *jh;
-        struct buffer_head *bh;
-        int locked;
-        int bufs = 0;
-        struct buffer_head **wbuf = journal->j_wbuf;
-
-        /*
-         * Whenever we unlock the journal and sleep, things can get added
-         * onto ->t_sync_datalist, so we have to keep looping back to
-         * write_out_data until we *know* that the list is empty.
-         *
-         * Cleanup any flushed data buffers from the data list.  Even in
-         * abort mode, we want to flush this out as soon as possible.
-         */
-write_out_data:
-        cond_resched();
-        spin_lock(&journal->j_list_lock);
-
-        while (commit_transaction->t_sync_datalist) {
-                jh = commit_transaction->t_sync_datalist;
-                bh = jh2bh(jh);
-                locked = 0;
-
-                /* Get reference just to make sure buffer does not disappear
-                 * when we are forced to drop various locks */
-                get_bh(bh);
-                /* If the buffer is dirty, we need to submit IO and hence
-                 * we need the buffer lock. We try to lock the buffer without
-                 * blocking. If we fail, we need to drop j_list_lock and do
-                 * blocking lock_buffer().
-                 */
-                if (buffer_dirty(bh)) {
-                        if (test_set_buffer_locked(bh)) {
-                                BUFFER_TRACE(bh, "needs blocking lock");
-                                spin_unlock(&journal->j_list_lock);
-                                /* Write out all data to prevent deadlocks */
-                                journal_do_submit_data(wbuf, bufs);
-                                bufs = 0;
-                                lock_buffer(bh);
-                                spin_lock(&journal->j_list_lock);
-                        }
-                        locked = 1;
-                }
-                /* We have to get bh_state lock. Again out of order, sigh. */
-                if (!inverted_lock(journal, bh)) {
-                        jbd_lock_bh_state(bh);
-                        spin_lock(&journal->j_list_lock);
-                }
-                /* Someone already cleaned up the buffer? */
-                if (!buffer_jbd(bh)
-                        || jh->b_transaction != commit_transaction
-                        || jh->b_jlist != BJ_SyncData) {
-                        jbd_unlock_bh_state(bh);
-                        if (locked)
-                                unlock_buffer(bh);
-                        BUFFER_TRACE(bh, "already cleaned up");
-                        put_bh(bh);
-                        continue;
-                }
-                if (locked && test_clear_buffer_dirty(bh)) {
-                        BUFFER_TRACE(bh, "needs writeout, adding to array");
-                        wbuf[bufs++] = bh;
-                        __jbd2_journal_file_buffer(jh, commit_transaction,
-                                                BJ_Locked);
-                        jbd_unlock_bh_state(bh);
-                        if (bufs == journal->j_wbufsize) {
-                                spin_unlock(&journal->j_list_lock);
-                                journal_do_submit_data(wbuf, bufs);
-                                bufs = 0;
-                                goto write_out_data;
-                        }
-                } else if (!locked && buffer_locked(bh)) {
-                        __jbd2_journal_file_buffer(jh, commit_transaction,
-                                                BJ_Locked);
-                        jbd_unlock_bh_state(bh);
-                        put_bh(bh);
-                } else {
-                        BUFFER_TRACE(bh, "writeout complete: unfile");
-                        __jbd2_journal_unfile_buffer(jh);
-                        jbd_unlock_bh_state(bh);
-                        if (locked)
-                                unlock_buffer(bh);
-                        jbd2_journal_remove_journal_head(bh);
-                        /* Once for our safety reference, once for
-                         * jbd2_journal_remove_journal_head() */
-                        put_bh(bh);
-                        put_bh(bh);
-                }
-
-                if (need_resched() || spin_needbreak(&journal->j_list_lock)) {
-                        spin_unlock(&journal->j_list_lock);
-                        goto write_out_data;
-                }
-        }
-        spin_unlock(&journal->j_list_lock);
-        journal_do_submit_data(wbuf, bufs);
-}
-
-/*
  * Submit all the data buffers of inode associated with the transaction to
  * disk.
  *
@@ -602,42 +431,15 @@ void jbd2_journal_commit_transaction(journal_t *journal)
          * Now start flushing things to disk, in the order they appear
          * on the transaction lists.  Data blocks go first.
          */
-        err = 0;
-        journal_submit_data_buffers(journal, commit_transaction);
         err = journal_submit_inode_data_buffers(journal, commit_transaction);
         if (err)
                 jbd2_journal_abort(journal, err);
 
-        /*
-         * Wait for all previously submitted IO to complete if commit
-         * record is to be written synchronously.
-         */
-        spin_lock(&journal->j_list_lock);
-        if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
-                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT))
-                err = journal_wait_on_locked_list(journal,
-                                                commit_transaction);
-
-        spin_unlock(&journal->j_list_lock);
-
-        if (err)
-                jbd2_journal_abort(journal, err);
-
         jbd2_journal_write_revoke_records(journal, commit_transaction);
 
         jbd_debug(3, "JBD: commit phase 2\n");
 
         /*
-         * If we found any dirty or locked buffers, then we should have
-         * looped back up to the write_out_data label.  If there weren't
-         * any then journal_clean_data_list should have wiped the list
-         * clean by now, so check that it is in fact empty.
-         */
-        J_ASSERT (commit_transaction->t_sync_datalist == NULL);
-
-        jbd_debug (3, "JBD: commit phase 3\n");
-
-        /*
          * Way to go: we have now written out all of the data for a
          * transaction!  Now comes the tricky part: we need to write out
          * metadata.  Loop over the transaction's entire buffer list:
@@ -655,6 +457,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         J_ASSERT(commit_transaction->t_nr_buffers <=
                  commit_transaction->t_outstanding_credits);
 
+        err = 0;
         descriptor = NULL;
         bufs = 0;
         while (commit_transaction->t_buffers) {
@@ -829,13 +632,6 @@ start_journal_io:
                                                  &cbh, crc32_sum);
                 if (err)
                         __jbd2_journal_abort_hard(journal);
-
-                spin_lock(&journal->j_list_lock);
-                err = journal_wait_on_locked_list(journal,
-                                                commit_transaction);
-                spin_unlock(&journal->j_list_lock);
-                if (err)
-                        __jbd2_journal_abort_hard(journal);
         }
 
         /*
@@ -860,7 +656,7 @@ start_journal_io:
            so we incur less scheduling load.
         */
 
-        jbd_debug(3, "JBD: commit phase 4\n");
+        jbd_debug(3, "JBD: commit phase 3\n");
 
         /*
          * akpm: these are BJ_IO, and j_list_lock is not needed.
@@ -919,7 +715,7 @@ wait_for_iobuf:
 
         J_ASSERT (commit_transaction->t_shadow_list == NULL);
 
-        jbd_debug(3, "JBD: commit phase 5\n");
+        jbd_debug(3, "JBD: commit phase 4\n");
 
         /* Here we wait for the revoke record and descriptor record buffers */
  wait_for_ctlbuf:
@@ -946,7 +742,7 @@ wait_for_iobuf:
                 /* AKPM: bforget here */
         }
 
-        jbd_debug(3, "JBD: commit phase 6\n");
+        jbd_debug(3, "JBD: commit phase 5\n");
 
         if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
@@ -966,9 +762,8 @@ wait_for_iobuf:
            transaction can be removed from any checkpoint list it was on
            before. */
 
-        jbd_debug(3, "JBD: commit phase 7\n");
+        jbd_debug(3, "JBD: commit phase 6\n");
 
-        J_ASSERT(commit_transaction->t_sync_datalist == NULL);
         J_ASSERT(list_empty(&commit_transaction->t_inode_list));
         J_ASSERT(commit_transaction->t_buffers == NULL);
         J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
@@ -1090,7 +885,7 @@ restart_loop:
 
         /* Done with this transaction! */
 
-        jbd_debug(3, "JBD: commit phase 8\n");
+        jbd_debug(3, "JBD: commit phase 7\n");
 
         J_ASSERT(commit_transaction->t_state == T_COMMIT);