From: "Aneesh Kumar K.V" Subject: [PATCH] ext4: Fix discard of inode prealloc space with delayed allocation. Date: Wed, 25 Feb 2009 21:52:02 +0530 Message-ID: <1235578922-7790-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Cc: linux-ext4@vger.kernel.org, "Aneesh Kumar K.V" To: tytso@mit.edu Return-path: Received: from e23smtp08.au.ibm.com ([202.81.31.141]:55881 "EHLO e23smtp08.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755003AbZBYQWQ (ORCPT ); Wed, 25 Feb 2009 11:22:16 -0500 Received: from d23relay01.au.ibm.com (d23relay01.au.ibm.com [202.81.31.243]) by e23smtp08.au.ibm.com (8.13.1/8.13.1) with ESMTP id n1PGMBEL028612 for ; Thu, 26 Feb 2009 03:22:11 +1100 Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay01.au.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n1PGMSJ4422118 for ; Thu, 26 Feb 2009 03:22:28 +1100 Received: from d23av01.au.ibm.com (loopback [127.0.0.1]) by d23av01.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n1PGMA30022286 for ; Thu, 26 Feb 2009 03:22:11 +1100 Sender: linux-ext4-owner@vger.kernel.org List-ID: With delayed allocation we should not/cannot discard inode prealloc space during file close. We would still have dirty pages for which we haven't allocated blocks yet. With this fix after each get_blocks request we check whether we have zero reserved blocks and if yes and we don't have any writers on the file we discard inode prealloc space. Signed-off-by: Aneesh Kumar K.V --- fs/ext4/file.c | 9 ++++++++- fs/ext4/inode.c | 6 ++++++ 2 files changed, 14 insertions(+), 1 deletions(-) diff --git a/fs/ext4/file.c b/fs/ext4/file.c index f731cb5..4e468e2 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -33,9 +33,16 @@ */ static int ext4_release_file(struct inode *inode, struct file *filp) { + int rsv_data_blocks; + + spin_lock(&EXT4_I(inode)->i_block_reservation_lock); + rsv_data_blocks = EXT4_I(inode)->i_reserved_data_blocks; + spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); + /* if we are the last writer on the inode, drop the block reservation */ if ((filp->f_mode & FMODE_WRITE) && - (atomic_read(&inode->i_writecount) == 1)) + (atomic_read(&inode->i_writecount) == 1) && + !rsv_data_blocks) { down_write(&EXT4_I(inode)->i_data_sem); ext4_discard_preallocations(inode); diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 51cdd13..26dcec4 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1038,6 +1038,12 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used) EXT4_I(inode)->i_reserved_data_blocks -= used; spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); + /* + * If have done all the pending block allocation and if the + * we don't have any writer on the inode + */ + if (!total && (atomic_read(&inode->i_writecount) == 0)) + ext4_discard_preallocations(inode); } /* -- tg: (694593e..) fix_prealloc_discard (depends on: master)