[01/12] Btrfs: Avoid superfluous tree-log writeout

Message ID	4AFBD666.6000406@oracle.com (mailing list archive)
State	Accepted
Headers	show Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id nAC9YtXc019640 for <patchwork-linux-btrfs@patchwork.kernel.org>; Thu, 12 Nov 2009 09:34:56 GMT Message-ID: <4AFBD666.6000406@oracle.com> Date: Thu, 12 Nov 2009 17:33:26 +0800 From: "Yan, Zheng" <zheng.yan@oracle.com> User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.4pre) Gecko/20091014 Fedora/3.0-2.8.b4.fc11 Thunderbird/3.0b4 MIME-Version: 1.0 To: linux-btrfs@vger.kernel.org, chris Mason <chris.mason@oracle.com> Subject: [PATCH 01/12] Btrfs: Avoid superfluous tree-log writeout Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index d4132aa..0cf1781 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -982,12 +982,12 @@ int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans, while (1) { ret = find_first_extent_bit(&log_root_tree->dirty_log_pages, - 0, &start, &end, EXTENT_DIRTY); + 0, &start, &end, EXTENT_DIRTY | EXTENT_NEW); if (ret) break; - clear_extent_dirty(&log_root_tree->dirty_log_pages, - start, end, GFP_NOFS); + clear_extent_bits(&log_root_tree->dirty_log_pages, start, end, + EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS); } eb = fs_info->log_root_tree->node; diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 8d1fd6d..30df7fd 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4918,8 +4918,16 @@ struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans, btrfs_set_buffer_uptodate(buf); if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { - set_extent_dirty(&root->dirty_log_pages, buf->start, - buf->start + buf->len - 1, GFP_NOFS); + /* + * we allow two log transactions at a time, use different + * EXENT bit to differentiate dirty pages. + */ + if (root->log_transid % 2 == 0) + set_extent_dirty(&root->dirty_log_pages, buf->start, + buf->start + buf->len - 1, GFP_NOFS); + else + set_extent_new(&root->dirty_log_pages, buf->start, + buf->start + buf->len - 1, GFP_NOFS); } else { set_extent_dirty(&trans->transaction->dirty_pages, buf->start, buf->start + buf->len - 1, GFP_NOFS); diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index c207e8c..b7b22c3 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -354,7 +354,7 @@ int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans, * those extents are sent to disk but does not wait on them */ int btrfs_write_marked_extents(struct btrfs_root *root, - struct extent_io_tree *dirty_pages) + struct extent_io_tree *dirty_pages, int mark) { int ret; int err = 0; @@ -367,7 +367,7 @@ int btrfs_write_marked_extents(struct btrfs_root *root, while (1) { ret = find_first_extent_bit(dirty_pages, start, &start, &end, - EXTENT_DIRTY); + mark); if (ret) break; while (start <= end) { @@ -413,7 +413,7 @@ int btrfs_write_marked_extents(struct btrfs_root *root, * on all the pages and clear them from the dirty pages state tree */ int btrfs_wait_marked_extents(struct btrfs_root *root, - struct extent_io_tree *dirty_pages) + struct extent_io_tree *dirty_pages, int mark) { int ret; int err = 0; @@ -425,12 +425,12 @@ int btrfs_wait_marked_extents(struct btrfs_root *root, unsigned long index; while (1) { - ret = find_first_extent_bit(dirty_pages, 0, &start, &end, - EXTENT_DIRTY); + ret = find_first_extent_bit(dirty_pages, start, &start, &end, + mark); if (ret) break; - clear_extent_dirty(dirty_pages, start, end, GFP_NOFS); + clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS); while (start <= end) { index = start >> PAGE_CACHE_SHIFT; start = (u64)(index + 1) << PAGE_CACHE_SHIFT; @@ -460,13 +460,13 @@ int btrfs_wait_marked_extents(struct btrfs_root *root, * those extents are on disk for transaction or log commit */ int btrfs_write_and_wait_marked_extents(struct btrfs_root *root, - struct extent_io_tree *dirty_pages) + struct extent_io_tree *dirty_pages, int mark) { int ret; int ret2; - ret = btrfs_write_marked_extents(root, dirty_pages); - ret2 = btrfs_wait_marked_extents(root, dirty_pages); + ret = btrfs_write_marked_extents(root, dirty_pages, mark); + ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark); return ret || ret2; } @@ -479,7 +479,8 @@ int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans, return filemap_write_and_wait(btree_inode->i_mapping); } return btrfs_write_and_wait_marked_extents(root, - &trans->transaction->dirty_pages); + &trans->transaction->dirty_pages, + EXTENT_DIRTY); } /* diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index d4e3e7a..93c7ccb 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -107,10 +107,10 @@ void btrfs_throttle(struct btrfs_root *root); int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans, struct btrfs_root *root); int btrfs_write_and_wait_marked_extents(struct btrfs_root *root, - struct extent_io_tree *dirty_pages); + struct extent_io_tree *dirty_pages, int mark); int btrfs_write_marked_extents(struct btrfs_root *root, - struct extent_io_tree *dirty_pages); + struct extent_io_tree *dirty_pages, int mark); int btrfs_wait_marked_extents(struct btrfs_root *root, - struct extent_io_tree *dirty_pages); + struct extent_io_tree *dirty_pages, int mark); int btrfs_transaction_in_commit(struct btrfs_fs_info *info); #endif diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index f51bf13..013cc6f 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -1977,10 +1977,11 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, { int index1; int index2; + int mark; int ret; struct btrfs_root *log = root->log_root; struct btrfs_root *log_root_tree = root->fs_info->log_root_tree; - u64 log_transid = 0; + unsigned long log_transid = 0; mutex_lock(&root->log_mutex); index1 = root->log_transid % 2; @@ -2014,24 +2015,29 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, goto out; } + log_transid = root->log_transid; + if (log_transid % 2 == 0) + mark = EXTENT_DIRTY; + else + mark = EXTENT_NEW; + /* we start IO on all the marked extents here, but we don't actually * wait for them until later. */ - ret = btrfs_write_marked_extents(log, &log->dirty_log_pages); + ret = btrfs_write_marked_extents(log, &log->dirty_log_pages, mark); BUG_ON(ret); btrfs_set_root_node(&log->root_item, log->node); root->log_batch = 0; - log_transid = root->log_transid; root->log_transid++; log->log_transid = root->log_transid; root->log_start_pid = 0; smp_mb(); /* - * log tree has been flushed to disk, new modifications of - * the log will be written to new positions. so it's safe to - * allow log writers to go in. + * IO has been started, blocks of the log tree have WRITTEN flag set + * in their headers. new modifications of the log will be written to + * new positions. so it's safe to allow log writers to go in. */ mutex_unlock(&root->log_mutex); @@ -2052,7 +2058,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, index2 = log_root_tree->log_transid % 2; if (atomic_read(&log_root_tree->log_commit[index2])) { - btrfs_wait_marked_extents(log, &log->dirty_log_pages); + btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark); wait_log_commit(trans, log_root_tree, log_root_tree->log_transid); mutex_unlock(&log_root_tree->log_mutex); @@ -2072,16 +2078,17 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, * check the full commit flag again */ if (root->fs_info->last_trans_log_full_commit == trans->transid) { - btrfs_wait_marked_extents(log, &log->dirty_log_pages); + btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark); mutex_unlock(&log_root_tree->log_mutex); ret = -EAGAIN; goto out_wake_log_root; } ret = btrfs_write_and_wait_marked_extents(log_root_tree, - &log_root_tree->dirty_log_pages); + &log_root_tree->dirty_log_pages, + EXTENT_DIRTY | EXTENT_NEW); BUG_ON(ret); - btrfs_wait_marked_extents(log, &log->dirty_log_pages); + btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark); btrfs_set_super_log_root(&root->fs_info->super_for_commit, log_root_tree->node->start); @@ -2147,12 +2154,12 @@ int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root) while (1) { ret = find_first_extent_bit(&log->dirty_log_pages, - 0, &start, &end, EXTENT_DIRTY); + 0, &start, &end, EXTENT_DIRTY | EXTENT_NEW); if (ret) break; - clear_extent_dirty(&log->dirty_log_pages, - start, end, GFP_NOFS); + clear_extent_bits(&log->dirty_log_pages, start, end, + EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS); } if (log->log_transid > 0) {

[01/12] Btrfs: Avoid superfluous tree-log writeout

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