From: Greg KH Subject: [patch 49/60] ext4: Fix discard of inode prealloc space with delayed allocation. Date: Tue, 09 Jun 2009 17:14:17 -0700 Message-ID: <20090610002351.008415019@blue.kroah.org> References: <20090610001328.251476848@blue.kroah.org> Cc: Justin Forbes , Zwane Mwaikambo , Theodore Ts'o , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, linux-ext4@vger.kernel.org, "Aneesh Kumar K.V" , Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@kernel.org Return-path: Received: from kroah.org ([198.145.64.141]:57397 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757600AbZFJDgb (ORCPT ); Tue, 9 Jun 2009 23:36:31 -0400 Content-Disposition: inline; filename=ext4-fix-discard-of-inode-prealloc-space-with-delayed-allocation.patch In-Reply-To: <20090610032135.GA19346@kroah.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: -stable review patch. If anyone has any objections, please let us know. ------------------ From: Aneesh Kumar K.V (cherry picked from commit d6014301b5599fba395c42a1e96a7fe86f7d0b2d) 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 Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/file.c | 3 ++- fs/ext4/inode.c | 8 ++++++++ 2 files changed, 10 insertions(+), 1 deletion(-) --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -39,7 +39,8 @@ static int ext4_release_file (struct ino } /* 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) && + !EXT4_I(inode)->i_reserved_data_blocks) { down_write(&EXT4_I(inode)->i_data_sem); ext4_discard_reservation(inode); --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1046,6 +1046,14 @@ static void ext4_da_update_reserve_space EXT4_I(inode)->i_reserved_meta_blocks = mdb; EXT4_I(inode)->i_allocated_meta_blocks = 0; spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); + + /* + * If we have done all the pending block allocations and if + * there aren't any writers on the inode, we can discard the + * inode's preallocations. + */ + if (!total && (atomic_read(&inode->i_writecount) == 0)) + ext4_discard_reservation(inode); } /*