From: Theodore Ts'o Subject: [PATCH 10/12] ext4: fix the number of credits needed for ext4_unlink() and ext4_rmdir() Date: Sat, 9 Feb 2013 16:53:50 -0500 Message-ID: <1360446832-12724-11-git-send-email-tytso@mit.edu> References: <1360446832-12724-1-git-send-email-tytso@mit.edu> Cc: Theodore Ts'o To: Ext4 Developers List Return-path: Received: from li9-11.members.linode.com ([67.18.176.11]:47609 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760838Ab3BIVxz (ORCPT ); Sat, 9 Feb 2013 16:53:55 -0500 In-Reply-To: <1360446832-12724-1-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: The ext4_unlink() and ext4_rmdir() don't actually release the blocks associated with the file/directory. This gets done in a separate jbd2 handle called via ext4_evict_inode(). Thus, we don't need to reserve lots of journal credits for the truncate. Note that using too many journal credits is non-optimal because it can leading to the journal transmit getting closed too early, before it is strictly necessary. Signed-off-by: "Theodore Ts'o" --- fs/ext4/ext4_jbd2.h | 6 ------ fs/ext4/namei.c | 4 ++-- 2 files changed, 2 insertions(+), 8 deletions(-) diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h index 302814b..c1fc2dc 100644 --- a/fs/ext4/ext4_jbd2.h +++ b/fs/ext4/ext4_jbd2.h @@ -59,12 +59,6 @@ #define EXT4_META_TRANS_BLOCKS(sb) (EXT4_XATTR_TRANS_BLOCKS + \ EXT4_MAXQUOTAS_TRANS_BLOCKS(sb)) -/* Delete operations potentially hit one directory's namespace plus an - * entire inode, plus arbitrary amounts of bitmap/indirection data. Be - * generous. We can grow the delete transaction later if necessary. */ - -#define EXT4_DELETE_TRANS_BLOCKS(sb) (2 * EXT4_DATA_TRANS_BLOCKS(sb) + 64) - /* Define an arbitrary limit for the amount of data we will anticipate * writing to any given transaction. For unbounded transactions such as * write(2) and truncate(2) we can write more than this, but we always diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 36a4afd..5f3d2b5 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2748,7 +2748,7 @@ static int ext4_rmdir(struct inode *dir, struct dentry *dentry) goto end_rmdir; handle = ext4_journal_start(dir, EXT4_HT_DIR, - EXT4_DELETE_TRANS_BLOCKS(dir->i_sb)); + EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); if (IS_ERR(handle)) { retval = PTR_ERR(handle); handle = NULL; @@ -2811,7 +2811,7 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry) goto end_unlink; handle = ext4_journal_start(dir, EXT4_HT_DIR, - EXT4_DELETE_TRANS_BLOCKS(dir->i_sb)); + EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); if (IS_ERR(handle)) { retval = PTR_ERR(handle); handle = NULL; -- 1.7.12.rc0.22.gcdd159b