From: Jan Kara Subject: Re: [PATCH 10/12] ext4: fix the number of credits needed for ext4_unlink() and ext4_rmdir() Date: Mon, 11 Feb 2013 17:28:30 +0100 Message-ID: <20130211162830.GM5318@quack.suse.cz> References: <1360446832-12724-1-git-send-email-tytso@mit.edu> <1360446832-12724-11-git-send-email-tytso@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ext4 Developers List To: Theodore Ts'o Return-path: Received: from cantor2.suse.de ([195.135.220.15]:38935 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757594Ab3BKQ2c (ORCPT ); Mon, 11 Feb 2013 11:28:32 -0500 Content-Disposition: inline In-Reply-To: <1360446832-12724-11-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sat 09-02-13 16:53:50, Ted Tso wrote: > 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. Nice spotting. The patch looks good. You can add: Reviewed-by: Jan Kara Honza > > 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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Jan Kara SUSE Labs, CR